Laure Milano

two European Courts, led to significant debates and some criticism from scholars, see inter alia

See the ECtHR judgments in Cases A and B

The construction of a European standard of ne bis in idem and the concept of final judicial decision in the EAW

Araceli Turmo

The existence of ne bis in idem as a fundamental right is not contested in European Union law or any of the legal orders of the Member States. This broad recognition of the importance of the principle is nevertheless only the first step towards its implementation in the context of the European arrest warrant (EAW) 1 or other instruments of European criminal law. Scholars have long drawn attention to the complexity of this principle and of the specific procedural mechanisms which allow its enforcement, in particular in the context of a multilevel legal order like the EU. The EAW is a comparatively recent area of development of the European Court of Justice' case law on ne bis in idem, as a result of the evolving competences of the EU as a whole, and of the Court more specifically, in the field of criminal law. The Court had initially constructed separate strands 2 of case law on the principle, the first being applicable in the fields of competition law and the second, with regard to criminal law, to Article 54 of the Convention Implementing the Schengen Agreement (CISA). 3 The development of the case law following legislative interventions in the field of EU criminal law did not help to resolve these inconsistencies. The coexistence of these different strands, to which one must add not only Article 50 of the European Charter of Fundamental Rights but also the further complicating factor of the case law of the European Court of Human Rights on Article 4 of Protocol 7, has long been criticised as unjustifiable inconsistency 4 and a source of uncertainty as to the EU standard for ne bis in idem. 5 Recent years have added even more complexity to this, perhaps most notably with the introduction of exceptions for certain cases of double prosecution, intended to mitigate the (unintended?) consequences of the characterisation of certain types of administrative enforcement as criminal in nature. 6 As Advocate General Bobek wrote in bpost in 2021, '[the principle as it has been developed in the case law of the ECJ] can hardly be characterised as (ne) bis in idem, but rather by now a quater or quinquies in idem, while uncertainty continues to plague bis as well. [START_REF]Case C-117/20[END_REF] ' Although recent judgments 8 have attempted to establish a more uniform understanding of ne bis in idem in EU law and to integrate within this a solution to the case of double proceedings, the results are not entirely satisfactory [START_REF]The Grand Chamber's Judgment in Case C-117/20 bpost: Disimproving the Essence of ne bis in idem' (European Law Blog[END_REF] and do not go as far as Advocate General Bobek had proposed. [START_REF]Opinions of Advocate General Bobek in Cases C-117/20, bpost, and C-151/20[END_REF] Indeed, as with any fundamental right and, more generally, any principle of law, the content of the norm is even more significant than its existence and may vary significantly according to the implementation choices made by legislative and judicial institutions. In the case of ne bis in idem, the extent of the protection granted varies significantly depending on the interpretation of a wide range of concepts which may be considered its component parts and is influenced by the choices made in other aspects of criminal and procedural law. This interpretation is the expression of a balance between competing interests present in any criminal justice system. On the one hand, the system must be capable of effectively prosecuting, judging and sentencing criminals. On the other, defendants (and the judicial system and legal order themselves) must be protected from endless or successive prosecution. A number of practical arrangements may also mitigate the impact of double prosecutions or convictions and be taken into account while applying the fundamental right, as demonstrated by the recent case law of the European Court of Justice which allows Member States to combine proceedings and sanctions both considered criminal in nature. The interpretation of the principle by judicial authorities must always take into account its different facets. As the ECJ has consistently ruled, ne bis in idem, as recognised under the AFSJ, is intended not only to prevent the impunity of persons definitively convicted and sentenced; but also to ensure legal certainty through the cross-border recognition of the final decisions of public bodies, in the absence of harmonisation or approximation of the criminal laws of the Member States. 11 In a recent judgment on the application of ne bis in idem in the context of the grounds for optional nonexecution of a EAW, the ECJ explained: 'the executing judicial authority must strike a balance between, on the one hand, preventing impunity and combating crime and, on the other, ensuring legal certainty for the person concerned, in order to attain the European Union's objective of becoming an area of freedom, security and justice, in accordance with Article 67(1) and (3) TFEU.' 12 The power exercised by judges when striking this balance between conflicting interests is particularly visible in the ways in which they interpret the building blocks of ne bis in idem in the context of different instruments of EU criminal law and, increasingly, the EAW. One crucial choice is how to define the 'idem': when should one consider the new proceedings to be for 'the same criminal offence' as the one for which the accused has already been acquitted or convicted? A broad understanding of the 'idem', including all possible legal characterisations of a set of behaviours, will lead to a generous application of ne bis in idem granting more protection to the accused, whereas an interpretation which restricts it to specific offences may allow successive trials and convictions regarding different legal characterisations of a single set of behaviours. This chapter focuses on another major component of ne bis in idem: the requirement of finality. This is the requirement that a final judicial decision 13 has already been made concerning the same person and the same facts, which means that the new proceedings constitute a 'bis'. In European Union law, this fundamental right is understood as applicable only insofar as the accused has already been convicted or acquitted in a final decision. This approach can also be found in the Framework Decision on the EAW, in which the grounds for non-execution of a warrant related to the existence of a previous judgment in a Member State or a third State both require this judgment to have been final. 14 The definition of a final judicial decision is, however, not specified by these instruments. A number of issues arise in relation to this concept when applying ne bis in idem in EU law, which are visible in a growing number of preliminary rulings by the ECJ. This paper will analyse the Court's recent case law on the finality requirement in the Framework Decision on the EAW in the light of the broader context of the pertinent provisions and precedents. The significant number of preliminary references on ne bis in idem in the context of the EAW illustrate not only the importance of the principle but also the need for European case law in order to set common standards for its implementation (1). The definition of what constitutes a 'final' decision capable of triggering ne bis in idem is one of the elements that requires judicial intervention. Its importance in the application of the fundamental right has led to the construction of an elaborate case law in other areas of EU criminal law (2). As the ECJ develops its case law on the concept in the context of the EAW, issues of consistency have started to appear as it becomes apparent that simple reliance on the existing precedents is not the Court's preferred approach (3).

Ne bis in idem: an essential guarantee for the European arrest warrant

In recent years, an increasing number of references have been made to the European Court of Justice on the issue of the scope and contents of ne bis in idem in the context of the application of the Framework Decision on the European Arrest Warrant. This case law demonstrates the importance of the principle with regard to this instrument -as in other aspects of police and judicial cooperation in criminal matters. It also confirms that it is not possible to rely on domestic law to define the contents of the principle or its scope, and European standards are necessary. The extended competence that the ECJ gained with the Treaty of Lisbon to assist Member States courts in the implementation of acts in the area of police and judicial cooperation has predictably led to a significant number of references on the provisions of the Framework Decision, and among them many on the appropriate standard for ne bis in idem and its effects in such proceedings. The case law of the ECJ on this fundamental right was, for a long time, mostly related to matters that are not formally considered part of criminal law (most notably, competition law) or to the implementation of Article 54 of the CISA which, as part of title III on 'police and security cooperation' between the Contracting States, was the main source of the development of ne bis in idem in EU criminal law. 15 Once preliminary references started to be made on the specific issue of the interpretation and application of this fundamental right with regard to the EAW, the Court of 13 Final acquittal or conviction in the language of Article 50 of the Charter. 14 Article 3(2) and Article 4(5) of the Framework Decision: 'the requested person has been finally judged'. 15 According to Article 54: 'A person whose trial has been finally disposed of in one Contracting Party may not be prosecuted in another Contracting Party for the same acts provided that, if a penalty has been imposed, it has been enforced, is actually in the process of being enforced or can no longer be enforced under the laws of the sentencing Contracting Party.' Justice had to contend with the complex issues arising out of this cooperation mechanism with regard to ne bis in idem. At the same time, it had to decide which of the standards set in its previous case law to follow, whether to create a new one -or whether to try to establish a common standard for EU law. If one follows the wording of the instruments, even within the field of police and judicial cooperation in criminal matters, the scope of the protection granted under the principle varies significantly. 16 The number and diversity of the references made specifically on the issue of ne bis in idem illustrate its importance but also the difficulties arising out of its application in such a context of transnational cooperation. The importance of this principle in the implementation of the Framework Decision on the EAW is apparent from the wording of the instrument itself. Indeed, ne bis in idem is, although not explicitly mentioned, included as one of the mandatory grounds for non-execution in Article 3(2)17 as well as two of the grounds for optional non-execution: Article 4(3)18 and, with respect to third countries, Article 4(5). 19 This fundamental right is of course an expected ground for the non-execution of a judicial decision emanating from a different State, since it would operate as a defence in the context of a single national legal system. However, the absence of any disagreement as to the legitimacy of ne bis in idem as a bar to the execution of European arrest warrants does not prevent disagreements from arising as to the precise scope of the bar and the circumstances in which it may be relied on. Although the universal acceptance of ne bis in idem as a fundamental right and essential component of the criminal justice system may make it appear straightforward, recent case law demonstrates the range of issues which arise out of its application. In the context of EU criminal law, a further complicating factor is that the principle is applicable across the borders of domestic legal systems. This is not the case under the ECHR where, as is well-known, the principle as set out in Article 4 of Protocol 7 only applies within the confines of one legal system. 20 This specificity of EU standard of ne bis in idem, which protects individuals from repeated trials or punishment 'within the Union' under Article 50 of the Charter, creates an increased number of challenges for judicial authorities interpreting and enforcing the principle in the context of EU instruments. The ECJ is not merely trying to construct a minimum standard for ne bis in idem which could be acceptable and applicable in the different Member States, it also has to look for way to allow for the application of ne bis in idem in the context of cooperation mechanisms which have to operate across legal systems. The cross-jurisdictional nature of the guarantee in the AFSJ transforms the nature and function of the principle 21 . It also makes it especially necessary to establish common understandings and definitions for the components of ne bis in idem. Although, in the absence of harmonisation, EU instruments must to a large extent rely on domestic law to define, for example, what constitues a final judgment or a criminal penalty triggering the application of the principle or what must be considered a repeated procedure on the 'same facts', it is impossible to ensure cooperation between the judicial authorities of different Member States if there is no common standard. Reliance on mutual trust is not sufficient, although it is indispensable. This explains the characterisation of ne bis in idem as an autonomous concept of EU law by the ECJ. 22 The provisions guaranteeing ne bis in idem in EU instruments need to be interpreted in the same way across the EU if they are to provide effective protection and contribute to the objective of offering citizens a borderless area of freedom, security and justice. This requires the ECJ to construct common definitions for the constitutive elements of ne bis in idem. [START_REF] Neagu | The Ne Bis in Idem Principle in the Interpretation of European Courts: Towards Uniform Interpretation[END_REF] The EAW is a perfect illustration of the type of police and judicial cooperation in which common standards for the notions required to apply ne bis in idem are necessary. The executing authorities must determine whether the person has indeed been 'finally judged' for 'the same facts' in any Member State, which requires being able to understand the scope of these conditions and the way in which they might apply in any of the legal orders of the European Union -or even beyond, under Article 4(5) of the Framework Decision.

The essential but elusive notion of final judicial decision in ne bis in idem

The criterion of the finality of the decision made on the conviction or the acquittal of the person is one of the essential conditions for the application of ne bis in idem in EU law. As such, it is a constitutive element for which the European Court of Justice has had to provide clarifications towards a common understanding applicable in the context of police and judicial cooperation. [START_REF]The notion of a 'final judicial decision' was in fact one of the points which the Greek proposal for a Framework Decision on ne bis in idem aimed to clarify (Initiative of the Hellenic Republic with a view to adopting a Coubncil Framework Decision[END_REF] The existence of a previous set of proceedings which have resulted in a final outcome is the condition for the possibility of the 'bis' which this principle precludes. [START_REF] Bas Van Bockel | The Interpretation and Application…[END_REF] The ECJ has frequently referred to finality as an essential condition for the application of ne bis in idem. Indeed, the ability of the judicial system to produce final decisions which settle disputes is an essential characteristic of any functioning legal system, and this fundamental right is only applicable when one such final resolution has been reached -although the nature of this final outcome and the way in which the system reaches it may be subject to varying interpretations. Of course the final decision must have been made in proceedings brought against the same person -someone who was merely interviewed as a witness in earlier proceedings may not rely on ne bis in idem. 26 This requirement is not specific to this legal system, and is generally presented as a common feature of ne bis in idem across national and international legal systems. It establishes a clear distinction between the rules related to ne bis in idem, which operates a posteriori, after a final judgment has been made in one legal system, [START_REF] Daniel | [END_REF] and rules which have a more preventative nature, such as lis pendens. Although both share similar objectives in that they aim to prevent the adoption of two distinct judicial decisions on the same issue, the rules related to lis pendens do so by regulating the relationship between simultaneous, parallel proceedings. Although the problem posed by positive jurisdiction conflicts which can lead to incompatible decisions is just as important, it is solved by instruments regulating conflicts of law and jurisdiction rather than ne bis in idem in EU law. [START_REF] Bas Van Bockel | The Ne Bis in Idem Principle in EU Law[END_REF] Ne bis in idem is meant to regulate the relationship between ongoing proceedings and preexisting final decisions, much like res judicata. In fact, ne bis in idem and res judicata share very similar functions and goals, although the former is perceived as more focused on protecting the rights of the individual (hence its recognition as a fundamental right) while the other, which applies beyond the scope of criminal law, is perceived as predominantly procedural in nature. The finality requirement in the context of ne bis in idem has sometimes been presented as a manifestation of res judicata. 29 This is not strictly true because they are distinct, albeit interrelated, principles, and the criteria as to what constitutes res judicata and what is a 'final' judgment or decision in the context of ne bis in idem does not always overlap. Most significantly, the fundamental right may be triggered by a decision which puts an end to the proceedings even if it is not a judicial act, such as an out-of-court settlement. 30 However, the reference is certainly useful and has in fact been used by the EU Courts. The obvious connection between the two principles means that the ECJ will sometimes rely on its case law related to res judicata in order to rule on a claim based on ne bis in idem, for example in order to rule that an order was not capable of triggering ne bis in idem because it did not rule on the substance of the case and, therefore, did not constitute res judicata. 31 This is in fact true with regard to other aspects of the criteria for the application of the principle, and not just with regard to the concept of 'finality' itself: the ECJ's early case law on the 'idem' clearly referred to criteria of similarity between two sets of proceedings which had been established in the context of the case law on res judicata as a bar to admissibility. 32 In the context of EU law, ne bis in idem is applied in relation to a variety of judgments and decisions, ranging from decisions of the European Commission which impose fines on undertakings to the judgments of national courts. The issue of what constitutes finality, in such a way as to make ne bis in idem applicable, therefore requires clarifications through case law. The concept cannot simply rely on national understandings of res judicata, even in the context of instruments such as the Framework Decision on the EAW, precisely because cooperation across the boundaries of domestic legal systems requires a common standard for the application of ne bis in idem. Police and judicial authorities in one Member State must be able to identify which judicial decisions made in a different Member State give rise to the application of ne bis in idem. One cannot rely on the precise wording of the applicable provisions either. Article 50 of the Charter only refers to acquittals and convictions, but is clearly applicable many other cases, including to decisions of the European Commission. 33 Article 54 of the CISA refers to a trial having been 'finally disposed of' while the EAW Framework Decision refers to persons who have been 'finally judged': one might argue that these should be interpreted as referring to a single, common autonomous concept of a 'final' decision for the purposes of ne bis in idem, which also matches that of the corresponding provision of the Charter. This was certainly what the ECJ stated in Mantello. 34 However, the lack of consistency inherent to the construction of different strands of case law related to specific instruments seems to prevent such a push towards uniformity. In any case, clarifications are required if these provisions are to be applicable with regard to the diverse range of judgments and decisions adopted at the national level and to which ne bis in idem might apply. The case law does establish some rules which generally allow for a simple application of the criteria for ne bis in idem. The first criterion relates to the status of the judgment or decision within the judicial system itself: it most no longer be susceptible to an appeal (to the exception of extraordinary remedies). In this regard, the criteria developed in order to define res judicata as a 29 Ibid., p. 224. 30 principle of EU law are helpful guides and entirely pertinent in order to apply ne bis in idem, insofar as they may apply both to judgments produced by EU Courts but also by national courts. The identification of a judicial pronouncement as final once the ordinary remedies are no longer open, either because they are time-barred or because the parties have made use of them, is not controversial and it constitutes a useful first step. The European Court of Human Rights refers to the decisions acquiring 'force of res judicata' (from the French force de chose jugée) as the criterion for finality under ne bis in idem, a characteristic acquired by judicial decisions once they are irrevocable due to the unavailability of ordinary remedies. [START_REF]Explanatory Report to the Protocol No. 7 to[END_REF] The ECJ has also always maintained that, in particular in the context of Article 54 of the CISA, it is not necessary that the decision be a judgment or the act of a judicial body. This was confirmed in the recent case WS v Bundesrepublik Deutschland (Notice rouge d'Interpol), [START_REF]Case C-505/19[END_REF] in which a German national brought an action against the Federal Republic of Germany seeking an order requiring that the Member State take the measures necessary to arrange for an Interpol red notice issued regarding him be withdrawn. The red notice had been issued at the request of the United States after proceedings regarding the same acts had been concluded in Germany by a settlement procedure under which he had paid a sum of money. The questions were whether ne bis in idem applies in such situations and whether, when the applicability of the principle is not yet established, the provisional arrest of a person who is the subject of a red notice is possible under Article 54 of the CISA, Article 50 of the Charter and Article 21(1) TFEU. In a decision reminiscent of the famous precedent in Gözütok and Brügge, (check si cited) the ECJ held that a decision made by a body other than a criminal court, such as the settlement in this case, may trigger ne bis in idem if it bars further prosecutions and is based on a determination as to the merits of the case. 37 The finality of the decision, its ability to bar further proceedings at the national level, was therefore the essential condition for the application of ne bis in idem under the CISA. Another, more difficult set of criteria has to do with the contents of the judgment or decision. Indeed, the fact that a decision may not (or no longer) be appealed is not necessarily sufficient for it to trigger ne bis in idem. Here, too, one might refer to the case law on res judicata where similar questions have been raised. The case law of the ECJ, both with respect to res judicata and to ne bis in idem, clearly states that not all decisions made by judicial authorities can produce such effects. However, the identification of the appropriate criteria to determine which types of decisions may do so, based on their contents, is not an easy task, especially considering the diversity of national legal systems in which EU criminal law may apply. With respect to res judicata, the case law regarding the orders and judgments made by the EU Courts themselves establishes as a core criterion whether the decision actually settles the dispute or part of it. This is also expressed in the phrase according to which res judicata 'extends to all matters of fact and law settled by a judicial decision'. [START_REF]Case C-281/89[END_REF] For example, the orders by which the President of the Court of Justice puts an end to a dispute following a request for a discontinuance do not contain any judicial ruling on an issue of fact or law. 39 The case law of the ECJ does not completely transpose this approach to ne bis in idem. Several cases on Article 54 of the CISA indicate that the matter is more complex. In Gasparini, 40 the Court did not follow Advocate General Sharpston's Opinion which proposed that a national court should be bound by an acquittal adopted in another Member State due to the offence becoming time-barred only if that decision was not merely final, but had involved consideration on the merits of the case. [START_REF][END_REF] This 'substance-based approach' to the principle, as she termed it, was justified by the idea that the rationale behind ne bis in idem presupposes that society has already had one chance to settle its accounts with the individual and that a society's self-imposed time-limits, which in effect lead it to surrender this chance, cannot as such be imposed upon other States in the context of the CISA. 42 All of the Member States which submitted observations also agreed that an assessment of the merits was necessary for Article 54 to apply. 43 Such an approach is consistent with the approach to res judicata under which a decision which does not actually settle the dispute is not truly a 'final decision' capable of producing the effects which attach to the concept -although once again the scope of the criteria is not entirely similar. An acquittal based on the statute of limitations would settle the dispute and become final for the purposes of res judicata. However, from the point of view of a more substantive principle such as ne bis in idem, the approach according to which such decisions do not 'settle' the dispute and may not therefore be considered sufficient cause to bar further action in another State seems justified. The Court, however, ruled that an acquittal must trigger ne bis in idem under Article 54 of the CISA even in the absence of any determination on the merits of the case. This was based on the objective of the provision, which is to ensure that persons can enjoy their freedom of movement in the Schengen Area once their cases are finally disposed of. 44 The aim of ensuring that individuals can rely on the fact that there has already been a final decision concerning a behaviour prevails over the idea that States should be able to justify a prosecution if the criminal liability of a person has not yet been assessed. Whether this formalistic approach should be understood to apply more generally was contested, however, considering the importance which the ECJ seemed to have given to the examination of the merits of the case in other precedents. 45 By contrast, the ECJ has ruled on the same provision that a decision which is made after examining the merits of the case, but which is not final, does not trigger ne bis in idem.The case at hand involved an order made before the charging of the suspected person, which suspended the proceedings but did not definitively bar further prosecution. 46 Once again, although this time more predictably, the formal status of the decision in the domestic judicial system prevailed over its contents in its ability to produce this effect. In Miraglia, 47 the ECJ held that ne bis in idem did not apply to a decision declaring a case to be closed after the public prosecutor had decided not to pursue the prosecution, without any determination as to the merits of the case, on the sole ground that criminal proceedings have been started in another Member State against the same defendant and for the same facts. In Kossowski, 48 the decision of the public prosecutor closing the investigation procedure was similarly not considered a final judicial decision for the purposes of ne bis in idem because the statement of reasons for the decision showed that no detailed investigation had been carried out. Gasparini does seem to stand out, however it does not appear unjustified with regard to the effects of acquittals based on time bars within domestic legal systems. All of this case law regarding the CISA illustrates the importance of the finality criterion as one of the essential constitutive elements of ne bis in idem. The criterion is often decisive, a factor which partly explains the number of references on this very issue. Another explaining factor for this case law is, however, that this criterion can be one of the most difficult to define, especially in a multinational and multilevel system in which there can be no consensus as to what constitutes a final judicial decision. A common definition, applicable at least within the scope of specific EU law instruments, is therefore a necessary contribution of the case law to the standard that must be enforced in the EU. However, as is apparent in particular with regard to the importance given to the contents of the decision which triggers the protection of ne bis in idem, the ECJ has fluctuated even in the context of the interpretation of a single instrument. The different wording the corresponding provisions and different aims of the instruments lead to further temptations to adjust the interpretation of the 'bis' according to the context.

Defining the 'bis' in the context of the European arrest warrant

Considering the importance of the condition that the 'bis' can only exist if there is a final judicial decision, the Framework Decision on the European arrest warrant was also expected to give rise to a significant amount of disputes on its precise definition. If the person has already been the subject of criminal proceedings and, as the case may be, a conviction in one State, this must be taken into consideration when deciding whether a warrant may be executed since it may constitute a violation of the principle. Articles 3(2), 4(3) and 4(5) of the Framework Decision establish different exceptions which may all be considered expressions of ne bis in idem. Articles 3(2) and 4(5) require that the previous judicial decision on which it is based has become final and has been enforced (or is no longer capable of being so). Article 4(3) allows the executing State to refuse to execute a warrant when its own judicial authorities have decided not to prosecute or to halt proceedings against the person for the same offence, or where a final judgment has passed in a Member State, in respect of the same acts, prevents further proceedings. A number of judgments provide valuable clarifications regarding the interpretation of the criterion of finality, as well as the related enforcement requirement, in the context of the ne bis in idem exceptions to the execution of EAW. If the executing authority has enough evidence that the principle is being violated, it must (or may, under Article 4) refuse to execute the warrant. In the absence of harmonisation, the default with regard to procedural matters is always to refer to the domestic legal systems which are called upon to cooperate. However, as with other instruments of EU law, the implementation of these provisions of the Framework Decision at the national level requires some common interpretation of the conditions under which ne bis in idem might be triggered. This approach extends to the notion of a final judicial decision, which can therefore not entirely depend on the decision's status in the legal system where it originated. Of course, finality must be understood in relation with the other criteria -a decision is only 'final' for the purposes of ne bis in idem if it covers the same person and the same facts as the newly issued warrant. A request for further information from the issuing Member State might serve to determine whether there is in fact an 'idem'. 49 As Advocate General Bobek wrote in a more recent case, for the principle ne bis in idem to be validly triggered, there must be a final statement from a Member State that authoritatively defines the extent of the idem that may then start precluding the ne bis.' 50 The Court of Justice has also ruled that the question whether a person has been 'finally' judged, for the purposes of Article 3(2) of the Framework Decision, is determined by the law of the Member State in which the judgment was delivered. 51 This means that the decisive factor is whether the judicial decision has the effect, under domestic law, of barring any further prosecution for the same acts. The finality of a judicial decision relied upon in a defence based on ne bis in idem must therefore, first and foremost, be determined on the basis of the status and effects of that decision under the law of the State where it was issued. In the same judgment, the ECJ invited executing authorities to make use of the cooperation arrangements provided for in Article 15(2) of the 49 Ibid., para. 49. 50 Framework Decision in order to ask the authority of the State where the judgment was delivered the precise nature of that judgment. [START_REF]Case C-505/19[END_REF] In an effort to establish a common standard across EU criminal law and to facilitate the interpretation of the Framework Decision on the EAW, the ECJ had also indicated that; in view of their shared objective, the interpretations of ne bis in idem it has given in the context of Article 54 of the CISA must be equally valid in the context of Article 3(2) of the Framework Decision. 53 However, recent case law seems to call this into question with respect to the issue of finality, in particular the judgment of the Court in AB. 54 The proceedings in Slovakia regarded the possible issuance of a EAW in respect of one of the accused persons in a case which had previously led to a final judgment. This judgment, which had the effects of an acquittal, was based on an amnesty which was decided before a determination was made on the substance of the case, and was later revoked. However the judgment had become final by the time the amnesty was revoked. Under Slovak law, the revocation of the amnesty entailed the annulment of decisions adopted on that basis and thus removed the legal obstacles to prosecutions, without the need for specific decisions or proceedings.

The ECJ chose 55 a definition of the concept of final judicial decision for the purposes of ne bis in idem as requiring a determination on the merits of the case, meaning that ne bis in idem was not triggered by the final judgment in such a situation. It justified this, first, by analogy to Article 54 CISA and the judgments in cases Miraglia 56 and Kossowski. 57 Advocate General Kokott had also cited ECtHR judgment Mihalache v Romania in this regard. 58 The ECJ followed Advocate General Kokott in stating [START_REF]Para. 57 of the judgment in AB, referring to para[END_REF] that this interpretation was confirmed by Article 50 of the Charter which refers to the person being 'convicted' or 'acquitted', both of which imply an examination of the substance of the case and a determination of the accused's criminal liability. The ECJ also justified this interpretation by reference to the objective established in Article 3(2) TFEU which includes the 'legitimate objective of preventing impunity for persons who have committed an offence'. [START_REF] Para | [END_REF] A decision to discontinue prosecution not on the basis of an examination of the substance of the case but on account of an amnesty could not, therefore, constitute a final decision giving rise to ne bis in idem. Although with some uncertainty as to the exact nature of the decision made following the amnesty in this case, the ECJ therefore found that the decision to discontinue prosecution on account of an amnesty generally does not involve a determination as to the merits of the case and that, therefore, the issuance of a EAW for the same facts is not precluded by ne bis in idem. 61 Beyond the procedural peculiarities of the Slovak case at issue, what must be noted here is the firm choice of a substantive interpretation of the notion of a final decision giving rise to the protection of ne bis in idem for the purposes of the EAW Framework Decision. Although the referring court informed the ECJ that the decision which initially brought the prosecutions to an end had the same effects as an acquittal under Slovak law and was tantamount to a decision on the 'substance' of the case, what mattered the most to the ECJ was that it appeared that the decision based on the amnesty had been made before any court could rule on the accused's criminal liability. Thus, before they were acquitted or convicted.

The two precedents cited by the ECJ on this issue were given in the context of Article 54 CISA on decisions made by public prosecutors to terminate criminal proceedings without any detailed investigation or determination as to the merits of the case. 62 These were therefore not truly comparable to what was presented as an acquittal in AB, except insofar as the ECJ was satisfied that the national decision was not based on a determination as to the substance of the case. The ECtHR judgment cited by the Advocate General, Mihalache, provided an interesting counterpoint in which the European Court found that ne bis in idem was applicable following a public prosecutor's order discontinuing criminal proceedings while imposing a fine on the applicant. This decision could be considered a 'final acquittal or conviction' triggering the application of the principle. That case raised issues somewhat similar to WS, which restated the importance of the fact that the final decision triggering ne bis in idem be based on a determination as to the merits of the case, in relation to a settlement which put an end to the proceedings following the payment of a sum of money determined by a public prosecutor. Yet, considering the ECJ's references to judgments made in the context of Article 54 of the CISA, one precedent which is conspicuously absent from the judgment is Gasparini. 63 . The justification for distinguishing conditions for the triggering of ne bis in idem in that case from the circumstances in AB is not clear. In both cases, the acquittal is decided without any examination of the criminal liability of the accused. A consensus interpretation of Gasparini was previously that it established the lack of any requirement of a 'substantive determination' for an acquittal to benefit from ne bis in idem 64 and some authors drew from this and other judgements a conclusion that, according to the ECJ, the substantive contents of the decision were not a decisive factor in the triggering of this guarantee. 65 An alternative interpretation, under which an acquittal which was not based on a substantive determination could not bar further prosecution in another Member State, certainly seemed equally defensible. 66 However, once the choice had been made so explicitly in the case law, any judgment which seems incompatible should require further justification. The fact that AB applies a different instrument of EU criminal law is not sufficient since the Court cites precedents related to the CISA in the grounds for the decision. One possible explanation 67 is that the judgment in Gasparini was explicitly based on the objective of Article 54 of the CISA, which is to ensure that persons who have their cases finally disposed of are able to enjoy their right to freedom of movement and are not prosecuted for the same acts in several Contracting States. This objective might justify a broad interpretation of the types of final decisions which might be covered under ne bis in idem, which would not be required in the case of the EAW, especially where the warrant is to be issued by authorities of the same Member State as the one where the initial prosecution had been carried out. However, this is not made explicit by the ECJ and would certainly merit clarification. The Court's approach is clearly different and some explanation ought to have been given as to the need to distinguish Gasparini or the specific requirements at play when the EAW is issued in the same Member State as the one where the earlier decision was made. It is difficult to tell whether AB should be read as an overruling of Gasparini or whether more case law will establish a clearer distinction, either between the scopes of application of ne bis in idem for 62 In Miraglia, the ECJ held that ne bis in idem did not apply to a decision declaring a case to be closed after the public prosecutor had decided not to pursue the prosecution, without any determination as to the merits of the case, on the sole ground that criminal proceedings have been started in another Member State against the same defendant and for the same facts. In Kossowski, the decision of the public prosecutor closing the investigation procedure was similarly not considered a final judicial decision for the purposes of ne bis in idem because the statement of reasons for the decision showed that no detailed investigation had been carried out. 63 Case C-467/04. 64 different instruments, or between different aspects of the two cases which justified these seemingly incompatible solutions. From the point of view of material justice, so long as no determination has been made as to the substance of the case and therefore the guilt or innocence of the accused, the matter cannot be considered to have been settled. One generally accepted exception to this, also justified by general requirements within the legal order and, in particular, the rights of the person accused, was the one set out in Gasparini: a time bar will lead the criminal justice system to consider the case 'closed' even in the absence of a decision on the substance of the case. In this regard, perhaps AB must be considered an expression of the usual rule, to which the exception made for the statute of limitations does not apply. As is often the case, it would have been preferable for the ECJ to explain this -or the other justifications for its decision not to follow (or cite) Gaspariniin its judgment. Similar questions related to the 'transfer' of interpretations established in the context of the CISA to the EAW were raised in X (European arrest warrant -Ne bis in idem), 68 on the enforcement requirement set out in Article 4(5) of the Framework Decision. As is apparent from the drafting of the provisions and the case law, this condition, which is also set out in Article 54 of the CISA, is closely related to finality: cases where there are questions as to the fulfilment of the enforcement requirement are often also cases in which questions may be raised as to the existence of a final question. The condition that there be a final decision is therefore often linked to a requirement that this decision has been executed or is no longer capable of being enforced, as in the Framework Decision on the EAW. In an earlier judgment in Bourquain, 69 the ECJ had to rule on a preliminary reference made in a very peculiar case on a conviction in absentia by the French Permanent Military Court while the accused had fled to the German Democratic Republic. When new proceedings were launched in Germany in 2002, Mr Bourquain sought to rely on this previous conviction which had indeed become final but had never been capable of being executed, first because if he had reappeared before the end of the limitation period, a new trial would have had to take place, second, because he had later benefited from an amnesty, third, because the limitation period for the execution of the sentence had passed. The ECJ held that such a conviction is 'final' even if, as was the case here, there was never a point when it could have been enforced. The fact that by the time proceedings started in Germany, the French penalty was no longer capable of being enforced due to the limitation period, was enough to rule that the first conviction barred the German authorities from instituting new criminal proceedings for the same acts. The specific procedural mechanisms at play in the French system in this case show how the finality of a judicial conviction may be inherently linked to its execution: the judgment is not entirely clear as to what the solution would be with regard to a conviction in absentia which can still be executed and for which the obligation to institute new proceedings if the person is arrested still applies.

In X, the reference requested guidance on the interpretation of the ground for non-execution when the requested person has been finally judged and the sentence may no longer be executed under the law of the third country, under Article 4(5). The person against whom the EAW had been issued claimed that he had been prosecuted and finally judged for the same acts in Iran. The Iranian decision had acquitted him in respect of some of those acts and sentenced him in respect of others to a term of imprisonment, which he had partially served, until he benefited from a general leniency measure granted by the Supreme Leader of Iran to mark the 40th anniversary of the Islamic Revolution. The reference to the ECJ raised the question of the margin of discretion granted to the executing judicial authority when applying the provision transposing Article 4(5), and asked whether the requirement that the sentence has been served or may no longer be executed could be fulfilled in a situation such as that at issue in the main proceedings. The Court held that the executing authority must have a margin of discretion to determine whether it is appropriate to refuse to execute a EAW on that ground. It recalled that, while exercising this power, it must strike a balance between the two aims of preventing impunity and combating crime, on the one hand, and ensuring legal certainty for the person concerned, on the other. 70 As such, therefore, the fact that a leniency measure which prevents the execution of the sentence was granted by a non-judicial authority and was not based on objective criminal policy considerations does not prevent it from meeting the requirements for the triggering of ne bis in idem under Article 4(5). 71 This judgment shows how crucial, but also how complex, the interpretation of the provisions which set out the finality requirement is for the implementation of the Framework Decision on the EAW is. The recognition of a final judicial decision as such, for the purposes of ne bis in idem, depends on the degree of trust which the executing judicial authority can place in the system in which it originated -a condition which depends on compliance with the standards of a fair trial 72 and which cannot be presumed beyond the Member States of the European Union. 73 Therefore, the executing authority cannot be required to recognise the final decision or its execution in the third State as producing the effects of ne bis in idem in its own legal system. However, the ECJ takes the view that such effects are, a priori, possible, even if the decision was not made by a judicial authority and not based on the implementation of a specific criminal policy or the merits of the case. This approach may be difficult to reconcile with the one in AB which seems to go in a different direction. If a decision can only be final for the purposes of the ne bis in idem exceptions to the EAW if it was made after some examination of the substance of the case, it seems at least questionable to rule that a leniency measure that bears no relation to the substance of the case can produce these effects with respect to the enforcement requirement. Interestingly, Advocate General Hogan had proposed a different ruling on the issue of the recognition of the remission of the sentence following the general leniency measure, because the logic of mutual trust could not operate outside the sphere of the judicial application of the law and therefore could not apply to a measure adopted by a political authority outside any criminal policy considerations. 74 The X case on the EAW, like AB, shows that the transfer of interpretations and precedents from cases on Article 54 of the CISA to the relevant provisions of the Framework Decision on the EAW is not straightforward.

***

The case law on the notion of a final judicial decision in the context of the ne bis in idem exceptions to the execution of a European arrest warrant is not yet sufficiently developed to draw definitive conclusions. What is clear is that, in part due to the inconsistencies present in the preexisting case law, the European Court of Justice has not yet established a clear and uniform standard for the concept in EU criminal law. Yet, the case law also confirms the importance of the criterion for the application of ne bis in idem in the context of the EAW, as in other instruments adopted in this field. The existence of a final judicial decision, or of a decision which can have the similar effect of barring further proceedings within a legal system, is an essential condition for the triggering of this fundamental right in EU law. References to domestic procedural law in order to determine which decisions should benefit from these effects are not sufficient, although they are a necessary starting point in an area which relies on mutual trust and cooperation between the judicial authorities of different States. However, for an autonomous concept to truly exist, the ECJ should make further efforts towards clarifying and unifying the constitutive elements of ne bis in idem across EU law, including those which are necessary to identify a 'bis'. With ne bis in idem remaining one of the major sources of preliminary references to the ECJ in this field, and the finality criterion one of the aspects which produces the largest amount of case law, we can expect further clarification -and complexity -to be introduced in the near future. The implementation of the right in the context of the EAW certainly remains an ongoing source of references. 75

  Joined Cases C-187/01 and 385/01, Gözütok and Brügge [2003] EU:C:2003:87, para. 31. 31 Order of the General Court in Case T-413/06 P-DEP, Gualtieri v European Commission [2012], EU:T:2012:624, paras 12-14.32 See, for example, the use of the phrase according to which 'the application of [ne bis in idem] is subject to the threefold condition of identity of the facts, unity of offender and unity of the legal interest protected', a clear reference to the criteria of similarity between two sets of proceedings required for the objection of inadmissibility based on res judicata: Joined Cases C-204/00 etc., Aalborg Portland and Others v EuropeanCommission [2004], EU:C:2004:6, para. 338. The same criteria appear in many cases, especially in competition law, for example in T-217/06, Arkema France and Others v European Commission [2011], EU:T:2011:251, para. 292. 33 Bas van Bockel, The Ne Bis in Idem Principle in EU Law, op. cit., p. 225.

34

Case C-261/09, Mantello, para. 38.

  Opinion of AG Bobek in Case C-505/19, WS [2020], EU:C:2020:939, para. 49.

51

Case C-261/09, Gaetano Mantello, para. 46.

  Bas van Bockel, The Ne Bis in Idem Principle in EU Law, op. cit., p. 227. 65 Daniel Flore, op. cit., p. 686. Contra, see André Klip, op. cit., arguing that Gasparini was incorrectly decided. 66 Bas van Bockel, ibid. 67 Lorenzo Cecchetti, 'Between Autonomy and Respect for National Prerogatives: Another Brick in the Case Law on the Ne Bis in Idem Principe in EU Law', EU Law Live, 17 January 2022.

Daniel Flore, Droit pénal européen, 2e éd. (Larcier 2014), 599-602.

'If the executing judicial authority is informed that the requested person has been finally judged by a Member State in respect of the same acts provided that, where there has been sentence, the sentence has been served or is currently being served or may no longer be executed under the law of the sentencing Member State'.

'Where the judicial authorities of the executing Member State have decided either not to prosecute for the offence on which the European arrest warrant is based or to halt proceedings, or where a final judgment has been passed upon the requested person in a Member State, in respect of the same acts, which prevents further proceedings'.

'If the executing judicial authority is informed that the requested person has been finally judged by a third State in respect of the same acts provided that, where there has been sentence, the sentence has been served or is currently being served or may no longer be executed under the law of the sentencing country'.

Article 4, para. 1: 'No one shall be liable to be tried or punished again in criminal proceedings under the jurisdiction of the same State […].'

Bas van Bockel, 'The Interpretation and Application of the Ne Bis In Idem Principle in the EU Area of Freedom, Security and Justice', in Sara Iglesias Sánchez and Maribel González Pascual (eds), Fundamental Rights in the EU Area of Freedom, Security and Justice (Cambridge University Press 2021), pp. 354-370, p. 357.

See the request for a preliminary ruling introduced by the Spanish Audiencia Nacional in Case C-164/22, which actually combines questions on Article 54 of the CISA and the Framework Decision on the EAW.


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Je souhaiterais tout d'abord remercier l'ensemble de mon jury de thèse, qui me fait l'honneur de juger ce travail aujourd'hui.

Merci au Professeur Jean-Louis GERARD, merci pour votre engagement pour l'anesthésieréanimation au CHU de Caen et dans toute la région. Merci pour votre écoute, votre soutien envers les internes du département. Merci d'avoir accepté ma dispo (2 fois), d'avoir appuyé mon projet d'ASR entre Avranches et… la réanimation chirurgicale (qui l'eût cru). Je vous

Merci Mathis, 1-0 pour le mur, merci pour ces 6 stages ensemble, ces rigolades, les tirages au sort en réa cardiaque, Lomepal à fond dans la voiture, les heures de WZ, les barbecues à Avranches, l'idée de prendre un poste à Avranches et sa concrétisation, Merci ! (cf courrier du chirurgien) Merci Alexandra, de m'avoir soutenu, écouté pendant ces 5 ans, merci pour toutes ces cartes postales, et de toujours être là pour moi.

Merci à tous les copains de l'internat de Caen, Gus, Arthur, Nicolas, Tanguy et Clémence et plus largement toute l'équipe Cherbourgeoise du premier semestre, à Sacha, premier neurogénéticien de France et à tous les co-internes, internes, IADEs, élèves IADEs, infimier-è-s, AS que j'ai côtoyé durant ces 5 ans (et demi), dont il est impossible de citer tous les prénoms et qui m'ont fait grandir toutes ces années, Merci ! Merci aux gars de Tours, depuis les premiers verres au Campus, en passant par les corpos ski, les dizaines de soirée, les soirées médecines et j'en passe…Merci à toute cette grande famille qui ne cesse de s'agrandir chaque année.

Merci à Alex pour toutes ces années, depuis l'externat et les sous-colles où on ne comprenait pas forcément tout, au choix de venir à Caen, à cette coloc…animée, et à tout ce qu'on partagera dans le futur j'en suis sûr.

Merci à Hubert (de terre), Jordane et Manon pour ce soutien pendant les dernières années avant le concours, c'est en partie grâce à vous que j'en suis arrivé là.

Merci Laurent, mon plus vieil ami, 18 ans qu'on se connait, l'Orbellière, le baseball, « il coule pas trop lui », Alfred Firmin, le voyage en Espagne avec le local, les virées Pointe de Courpain, les premières soirées dans la salle chez tes parents, les randos dans les Pyrénées, en Corse avec toutes ces ampoules aux pieds, l'arrivée de Marie puis du petit Malo. Malgré la distance je me suis toujours senti aussi proche de toi et encore aujourd'hui, tu es là pour ce moment si particulier pour moi. Merci pour tout.

Merci Antoine, tu sais la place que tu as dans ma vie depuis notre rencontre à Tours, ne change pas.

Merci à mes parents qui nous ont toujours fait passer avant eux et tout donné, qui nous ont éduqué avec amour, qui m'ont soutenu durant ces longues années (malgré mes redoublements), à Lucie, ma soeur préférée et à Rafa, mon frère préféré, vous êtes ce que j'ai de plus cher, je vous aime. Merci aussi à papi et mamie qui auraient tant voulu me voir devenir docteur, merci de m'avoir appris tant de choses (et fait tant de soupes et gâteaux durant l'externat).

Et enfin, Merci à Lucie Marie Juliette MARTIN, ma co-interne, ma meilleure amie, puis ma copine pour devenir ensuite ma fiancée et future femme. Merci de me supporter au quotidien (pas une mince affaire), d'être présente à mes côtés depuis plus de

Tables and figures

Tables:

Table 1: Characteristics of study population …………………………………………...…………10 Indeed, according to the intracranial pressure-volume relationship, the withdrawal of even a small amount of CSF results in a significant decrease in ICP and improves cerebral perfusion parameters [START_REF] Nwachuku | Intermittent Versus Continuous Cerebrospinal Fluid Drainage Management in Adult Severe Traumatic Brain Injury: Assessment of Intracranial Pressure Burden[END_REF]. Recently, a retrospective study highlighted that in a protocol-based management for traumatic brain injury, EVD allowed intracranial pressure control and avoided third tier therapeutic measures in 40% of cases [START_REF] Moyer | External ventricular drainage for intracranial hypertension after traumatic brain injury: is it really useful?[END_REF]. However, the 60% rate of EVD inefficiency confirms that EVD use in the context of TBI remains to be improved. Two areas of improvement are possible: identification of optimal EVD management and identification of TBI patients who are most likely to benefit from EVD. Currently no consensus on the best timing of EVD insertion exists [START_REF] Chau | Optimal Timing of External Ventricular Drainage after Severe Traumatic Brain Injury: A Systematic Review[END_REF]. However, considering its impact on ICP control and on inflammatory biomarkers, an earlier timing of insertion could improve the prognosis of TBI patients with ICH.

Thus, the primary objective of the study was to identify factors associated with long term outcome in TBI patients with ICH and CSF drainage. The secondary objective was to identify factors associated with long term outcome in the overall TBI population with CSF drainage.

Methods

Data source

All patients with traumatic brain injury (bleeding on initial Computer tomography (CT) scan) and intracranial pressure monitoring admitted to both intensive care between May 2011 and March 2019 were screened for inclusion. Inclusion criteria were: patients with TBI and EVD insertion were included. In order to define the population of TBI with ICH, ICH was defined as an ICP > 25 mmHg requiring at least the first-tier therapy. Data for all participating patients were extracted from a prospective trauma registry and completed by information from the medical files if appropriate or required. The first CT-scan after external ventricular drain insertion was analyzed to determine the occurrence of hemorrhagic complications (intracerebral hematoma).

Timing of External ventricular drain insertion

After admission and initial CT-scan, prompt evacuation of subdural and/or epidural hematoma was performed when required. Primary decompressive craniectomy was defined as a craniectomy performed during initial surgery when dura mater closure or bone flap replacement was impossible.

ICP was monitored after TBI, according to Brain trauma foundation guidelines [START_REF]Guidelines for the Management of Severe Traumatic Brain Injury[END_REF], in all patients with an intraparenchymal probe (Codman ® or Sophysa ® ) usually inserted in the right frontal lobe.

External ventricular drain (antibiotic free) insertion was decided according to a standardized protocol for ICH control that was followed in both center:

First Tier interventions to control ICP:

• Initiation of appropriate sedation and analgesia,

• Head elevation (30 to 45 degrees),

• Optimization of venous return from head,

• Fever control (temperature <38°C),

• Optimization of PaCO2 through mechanical ventilation (36 to 40 mmHg),

• Repeated assessment of cerebral autoregulation with transcranial doppler; individualized adaptation of cerebral perfusion pressure (CPP) if indicated with vasopressors.

Second Tier:

• Repeat brain CT-Scan to rule out evolution of existing lesions suitable for surgical intervention,

• Intermittent bolus administration of hypertonic saline if ICP > 25 mmHg,

• Continuous neuromuscular paralysis in adequately sedated patients if bolus administration proves to lower ICP,

• Consider cerebrospinal fluid drainage: EVD with continuous drainage strategy.

Third Tier:

• Decompressive craniectomy (secondary decompressive craniectomy),

• Barbiturate coma,

• Therapeutic hypothermia (Target temperature of 34°-36°C).

Definition of good outcome

A good outcome was defined as a Glasgow Outcome Scale (Supplementary materials:

2) of more than 3 at 3 months after the trauma. Conversely, a bad outcome was defined as a Glasgow Outcome Scale of one to three at 3 months.

Definition of complications

External ventricular drainage associated bacterial ventriculitis was defined according to the 2017 Infectious Diseases Society of America's Clinical Practice Guidelines for Healthcare-Associated Ventriculitis and Meningitis [START_REF] Tunkel | Infectious Diseases Society of America's Clinical Practice Guidelines for Healthcare-Associated Ventriculitis and Meningitis*[END_REF]. Hemorrhage complications were identified on the first brain CT-scan after EVD and were defined as a hematoma requiring surgical intervention or exerting any mass effect on the brain on CT-scan. Hematoma expansion was defined as an augmentation of size of preexisting brain lesion (compared to the previous brain CT-scan).

EVD obstruction is defined as an occlusion of CSF drain requiring EVD replacement.

Data collection

The following data were collected for every included patient: age, gender, severity of the traumatic brain injury: prehospital Glasgow coma score (GCS), pupil abnormalities (areactive mydriasis or unilateral pupil abnormalities), hypoxemia (SpO2 < 92%) or hypotension (PAS < 90 mmHg), initial transcranial doppler exam, initial intracranial pressure. ICU characteristics: time between admission and EVD, osmotherapy before EVD, primary and secondary decompressive craniectomy, EVD associated bacterial ventriculitis, length of stay in ICU, length of CSF drainage, ICU mortality, EVD failure (defined as third tier therapies use and/or death due to raised ICP), EVD complication and decision to withdraw life sustaining treatment. Radiological data from brain CT-scan (initial whole-body CT-scan, brain CT-scan before and after EVD). Simplified acute physiology score (SAPS II) [START_REF] Gall | A new Simplified Acute Physiology Score (SAPS II) based on a European/North American multicenter study[END_REF] and the in-hospital mortality were also recorded. Glasgow Outcome Scale (GOS) (17) at 3 months was assessed using the neurological examination reported in the medical record.

Statistical analysis

Categorical variables are reported as counts and proportions, and continuous variables as median and inter quartile range and were performed by Excel (Microsoft®, Redmond, USA).

A univariate analysis was performed using the Fischer Exact test for categorical variables and the t-test or Wilcoxon test for continuous variables. P values < 0.2 determining variables entered into a multivariable logistic regression model. The hypothesis of Logit linearity of the quantitative variable was verified after modeling the log (OR) according to the variables concerned. In the absence of loglinearity, the quantitative variables were dichotomized according to their median values. The statistical analysis was performed on the R platform (R:

A Language and Environment for Statistical Computing, R Foundation for Statistical Computing, Vienna, Austria).

Results

Study population

Among 496 patients admitted for TBI in Beaujon (Paris) Trauma center from May 2011 to March 2019 and 175 in Caen (Normandy) Trauma center. Respectively 83 and 74 patients treated with EVD were included (n=157). 3 patients had to be excluded after medical record reading and missing GOS at 3 months (Figure 4). 14 patients did not have ICP measurement before EVD placement.

Discussion

This study demonstrated that an initial high GCS and a lower age were factors associated with good prognosis at 3 months after ICH in TBI patients with ICH requiring EVD placement. On contrary, pupillary abnormalities and effacement of the sulci (on the initial CTscan) were factors associated with bad prognosis at 3 months.

Prognosis of TBI patients requiring CSF drainage

Only 46% of patients had a good prognosis at 3 months after TBI and ICH requiring EVD placement. This result is congruent with the recent study of McCrea et al. In this cohort study, a good functional outcome at 3 months (defined as an extended Glasgow outcome scale ≥4) was found in 45% and 69% of patients with severe and moderate TBI respectively [START_REF] Mccrea | Functional Outcomes Over the First Year After Moderate to Severe Traumatic Brain Injury in the Prospective, Longitudinal TRACK-TBI Study[END_REF].

The CRASH trial collaborators, which is the most widely used model for TBI pronostication, has evaluated different models to predict relevant outcomes in more than 10,000 patients with traumatic brain injury [START_REF] Mrc Crash Trial | Predicting outcome after traumatic brain injury: practical prognostic models based on large cohort of international patients[END_REF]. The basic model included four clinical predictors that were associated with neurological prognosis (age, Glasgow coma scale, pupil reactivity, and the presence of major extracranial injury) and was completed in the CT model by brain lesion information (presence of petechial haemorrhages, obliteration of the third ventricle or basal cisterns, subarachnoid bleeding, midline shift, and non-evacuated haematoma). The factors associated with poor outcome identified in our study seem coherent with the CRASH trial which showed that the presence of the obliteration of third ventricle or basal cisterns was associated with the worst prognosis at 14 days. Furthermore, the association of epidural haematoma with relatively good outcome has been demonstrated in patients with moderate to severe TBI. This finding was confirmed in a recent large retrospective study by the CENTER-TBI group in which epidural haematoma was not associated with 6 months unfavourable outcome. This study has also confirmed the negative impact on long term outcome of subdural haematoma and subarachnoid haemorrhage. In our study the absence of subdural haematoma and subarachnoid haemorrhage as factors associated with the 3 months prognosis could be explained by the specific characteristics of the cohort which has a relatively small sample size and focus on a highly selected population (TBI patients with ICH which required CSF drainage). Thus, all the findings on long term outcome in our specific population of TBI is congruent with the previous literature and could question the study of Griesdale et al [START_REF] Griesdale | External ventricular drains and mortality in patients with severe traumatic brain injury[END_REF]. In this study, the authors concluded that EVD use was associated with increased mortality; however, this was driven entirely by those patients with a best GCS ≥ 6. Thus, the brain trauma foundation in its last version has considered CSF drainage in TBI only in patients with GCS <6 [START_REF]Guidelines for the Management of Severe Traumatic Brain Injury[END_REF]. The result of our study tends to confirm that the prognosis of patient with TBI and CSF drainage did not show any specificity and that factors associated with poor prognosis are common with previous findings. Thus, CSF drainage should not be restricted to patients with a Glasgow coma score < 6 and should be considered as a therapeutic option for ICH regardless of the initial GCS.

Our study demonstrated no effect of the timing of EVD placement on the GOS at 3 months. However, patients with a good functional outcome appeared to have a later EVD placement (28 (16 to 58) vs 15 (8 to 52)) but this result failed to reach statistical significance.

This difference could reflect that intensity of ICH (and its rapidity to increase) is a key factor for long term outcome. This hypothesis is consistent with the fact that sulcus effacement on initial CT-scan is associated with bad prognosis at 3 months in univariate and multivariate analysis. Interestingly, EVD failure to control ICP was not statistically different in patients with good and bad outcome. This result confirms those previously published by Huijben et al. In their study, the authors have demonstrated that the use of high therapeutic index level treatment was not significantly associated with worse long term outcome [START_REF] Huijben | Use and impact of high intensity treatments in patients with traumatic brain injury across Europe: a CENTER-TBI analysis[END_REF].

In the 14 patients with EVD insertion without ICH evidence there was no difference in terms of GOS at 3 months, which may suggest the absence of effectiveness of "prophylactic"

or "very early" EVD. However, this observation should be taken cautiously and further studies should explore whether early CSF drainage may, in a subgroup of patients, prevent refractory intracranial hypertension and possibly improve outcome.

CSF drainage complications

In our cohort study, a complication occurred in 24 patients (16%). This low rate of complications is consistent with the previous studies and confirms the relative low risk of CSF drainage in the context of ICH after TBI. It suggests that EVD insertion had a good risk-benefit ratio when needed. In our study, the ventriculitis rate of 6% was low compared to the 8-22%

rates reported in the literature [START_REF] Arabi | Ventriculostomy-associated infections: incidence and risk factors[END_REF][START_REF] Lozier | Ventriculostomy-related infections: a critical review of the literature[END_REF][START_REF] Chi | Infections associated with indwelling ventriculostomy catheters in a teaching hospital[END_REF]. These results appear consistent with previous studies and confirm that the rate of ventriculitis in a selected population of TBI is lower than in population compiling patients with subarachnoid hemorrhage, hydrocephalus, intracerebral hemorrhage and TBI. The higher volume of intraventricular blood in subarachnoid hemorrhage is associated with a longer length of CSF drainage, a greater risk of catheter obstruction and finally a higher risk of infection. This could explain the low infection rate in isolated TBI in our study. No intraparenchymal bleeding nor hematoma expansion as a side effect of CSF drainage were recorded.

Limitations

This report is characterized by few limitations and our results should be interpreted cautiously. First, this is a monocentric observational study with serious risk of bias.

Second, even if this study is one of the largest reports of EVD for TBI, the sample size and an ensuing lack of power could have fault to identify significant results like the time between admission and EVD insertion.

Third, the ICP control protocol described in this study is in accordance with national guidelines, discrepancy with other local protocols may persist and results should be interpreted accordingly.

Fourth, the definition of good outcome by a GOS > 3 at 3 months is questionable. GOS is less accurate than the GOS extended, however the granularity of the data in medical records did not allow us to estimate the GOS-E.

Finally, the choice of a 3-month evaluation could be insufficient considering that TBI patients frequently demonstrated functional gains between 3 months and one-year postinjury.

Conclusion

This study suggests that in a selected population of TBI with ICH requiring CSF drainage, high initial GCS was factor associated with a good functional prognosis at 3 months.

Conversely, a higher age, presence of pupil abnormalities and effacement of the sulci on the initial CT-Scan were associated with bad GOS at 3 months. The results of our study tend to confirm that the prognosis of patients with TBI and CSF drainage did not show any specificity and that factors associated with poor prognosis are common with previous findings.

  Abbreviations

Figure 1 : 1 Figure 2 : 2 Figure 3 :Figure 4 : 8 Summary 1 . 1 2. 4 2 3 4 2. 4 6 2. 6 3 . 8 3. 1

 112234811434466381 Figure 1: Pathophysiology of secondary brain injury……………………………...………...……..1

4. Discussion……………………………………………………………………………………….. 18 4. 1 7 .

 1817 Prognosis of TBI patients requiring CSF drainage…………………………………...18 4.2 CSF drainage complications……………………………………………………………20 4.3 Limitations………………………………………………………………………………..20 5. Conclusion………………………………………………….……………………………………22 6. References………………………………………………………………..……………..............23 Supplementary materials…………………………………………………....….....................26 1. Introduction Traumatic brain injury (TBI) is a major worldwide public health concern affecting mostly young people, victims of road traffic accidents, and elderly, victims of falls (1) (about sixty-nine million people every year) (2). In Europe 262 per 100,000 individuals suffer from TBI (3). In patients with severe TBI, the majority of deaths is associated with increased intracranial pressure (ICP) (4). Primary injuries follow the trauma such as hematomas, contusions, axonal injury or skull fractures. Secondary injuries (Fig 1) develop over time due to molecular and cellular changes that might lead to development of cytotoxic or vasogenic brain edema. TBI represent also a major cause of long-term disabilities among survivors (5).

Figure 1 :

 1 Figure 1: Pathophysiology of secondary brain injury

Figure 2 :

 2 Figure 2: The Monroe-Kellie doctrine

Figure 3 :

 3 Figure 3: External Ventricular Drainage

2. 1 Ethics

 1 This retrospective data use was approved by an Institutional Ethics Committee (Comité de Protection des Personnes Nord-Ouest III, ref. A12-D35-VOL.13, September 25, 2012) for Caen and by the Institutional Review Board (Comité de Protection des Personnes, Paris VI, Pitié, président Pr Laurent Lacapelle, Bâtiment de la Force, 47 Boulevard de l'Hôpital, 75651 Paris Cedex 13, 28 November 2012) and from the Advisory Committee for Information Processing in Health Research (Comité consultatif sur le traitement de l'information en matière de recherche dans le domaine de la santé, autorisation 11.305bis) and from the National Commission for Data Protection (Commission Nationale de l'Informatique et des Libertés, autorisation 911461) for Beaujon. 2.2 Study design This retrospective cohort study was conducted in two designated Level 1 traumacenter and teaching hospital (Centre Hospitalier Universitaire Caen Normandie and Beaujon Hospital -Clichy) between May 2011 and March 2019. Guidelines for reporting this retrospective study were from the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement (supplementary material: 1) (14).

Figure 4 :

 4 Figure 4: Flowchart of the study

Table 2 :

 2 Characteristics between good and bad GOS at 3 months………………………….…12

Table 3 :

 3 Factors of good prognosis GOS at 3 months after TBI and ICH (>25mmHg) with EVD insertion………………………………………........……………………...13

Table 4 :

 4 TBI patients with ICH and EVD insertion characteristics regarding their prognosis at 3 months………………………………………………………………………...[START_REF] Tunkel | Infectious Diseases Society of America's Clinical Practice Guidelines for Healthcare-Associated Ventriculitis and Meningitis*[END_REF]

Table 5 :

 5 Factors of good prognosis GOS at 3 months after TBI with EVD insertion…………………………………………………………..........................………………...16

	Figures:

Table 1 )

 1 . 62% of patients had a severe TBI, and 60% had an initial GCS motor component inferior to 5. The initial ICP was 17 mmHg [10; 30]. 58% (n=89/154) of patients received osmotherapy or barbiturate bolus before EVD placement. The EVD insertion occurred after a median time of 19 hours [IQR 8; 53] after admission and the median length of CSF drainage was 10 days [IQR 5; 15] (Table 1). All the results are presented in Table 1.

	The median SAPS II was 45 [IQR 35; 54]. 116 patients (75%) were sedated and mechanically
	ventilated during pre-hospital management. 25% of patients (n=38) presented pupil
	abnormalities and 17% (n=26) of patients suffered from hypoxemia or hypotension during the
	initial management. A transcranial Doppler was realized for all patients, and among them, 43
	(28%) showed signs of elevated intracranial pressure (pulsatility index on Transcranial Doppler
	> 1,4).

Table 1 :

 1 Characteristics of study population Factors associated with good prognosis at 3 months in TBI patients with ICH > 25mmHg

	All patients, n=154

Continuous variables are described by the median and interquartile range (IQR). Categorical variables are described by the number of patients and the corresponding percentage (%). EVD: external ventricular drainage; GCS: Glasgow coma score; CSF: Cerebrospinal fluid; CT: computer tomography; ICU: Intensive care unit; GOS: Glasgow outcome scale

3.2

Table 2 :

 2 TBI patients with ICH and EVD insertion characteristics regarding their prognosis at 3 months (n=140) Continuous variables are described by the median and interquartile range IQR. Categorical variables are described by the number of patients and the corresponding percentage (%).

		Bad prognosis	Good
	Parameters	at 3 months	prognosis at 3	p-value
		(n=78)	months (n=62)
	Clinical Charateristics
	Male	58 (74)	50 (81)	0.38
	Female	20 (26)	12 (19)	0.38
	Age (years)	39 (26 to 55)	30 (23 to 46)	0.015
	SAPS II	48 (43 to 58)	35 (27 to 46)	<0.0001
	Initial Glasgow coma score	6 (4 to 9)	8 (5 to 11)	0.0026
	Initial motor Glasgow coma score	3 (1 to 5)	4 (3 to 6)	0.0026
	Initial Glasgow coma scale <8	56 (72)	32 (52)	0.014
	Hypotension (Systolic Blood pressure < 90mmHg)	9 (12)	6 (10)	0.72
	Hypoxia (Oxygen stauration < 92%)	8 (10)	3 (5)	0.24
	Pupil abnormalities	29 (37)	7(11)	<0.0001
	Sedation	63 (81)	44 (71)	0.17
	PI on Transcranial Doppler > 1,4	19 (37)	24 (57)	0.056
	Initial intracranial pressure (mmHg)	16 (10 to 35)	19 (13 to 29)	0.46
	Secondary brain insults of systemic
	origin uncontrolled with treatment	18 (23)	13 (21)	0.77
	before EVD
	Bolus of osmotherapy before EVD	47 (60)	22 (36)	0.0036
	Bolus of barbiturate before EVD	12 (15)	5 (8)	0.19
	Time from admission to EVD placement (hours)	15 (8 to 52)	28 (16 to 58)	0.064
	Failed EVD (all causes)	37 (47)	26 (42)	0.52
	Withdrawal of care	21 (27)	1 (2)	<0.0001
	Bolus of barbiturate after EVD	29 (37)	19 (31)	0.42
	Primary decompressive craniectomy	11 (14)	10 (16)	0.74
	Lenght of CSF drainage (days)	9 (5 to 15)	10.5 (8 to 15)	0.28
	Ventriculitis	5 (6)	2 (3)	0.39
	Secondary decompressive craniectomy	17 (22)	12 (19)	0.83
	In ICU mortality	40 (51)	0 (0)	<0.0001
	ICU length of stay (days)	20 (9 to 36)	24 (17 to 31)	0.12
	Hematoma on EVD path	2 (3)	7 (11)	0.078
	Previous EVD CT-Scan characteristics
	Traumatic Sub-Arachnoid Hemorrhage	61 (78)	46 (74)	0.58
	Epidural hematoma	9 (12)	19 (31)	0.005

Table 3 :

 3 Factors associated with good prognosis at 3 months after TBI and ICH (>25mmHg)

	(n=62)
	Parameters	OR	95% CI	p-value
	Clinical Charateristics
	Age (years)	0.96	[0.93; 0.98]	0.009
	Initial Glasgow coma score	1.21	[1.06; 1.37]	0.003
	Epidural hematoma	2.75	[0.98; 7.75]	0.054
	Pupil abnormalities	0.28	[0.1; 0.76]	0.012
	Effacement of sulci	0.23	[0.08; 0.66]	0.007
	3.3 Factors associated with good prognosis at 3 months in the overall TBI population with CSF
	drainage
	a) Univariate analysis
	In the good prognosis group, patients were younger (33 (23; 48.5) vs 43 (26; 56)
	p=0.036), with a lower severity evaluated by the SAPS II (39 (28; 47) vs 48 (44; 58) p<0.0001)

and the initial GCS

(8 (5; 12)

vs 6 (4; 9) p=0.005). Moreover, patients with good prognosis had fewer pupil abnormalities (9 (13) vs 29 (35) p=0.0014). Neither hypoxemia (4 (6) vs 8

[START_REF] Geeraerts | Management of severe traumatic brain injury (first 24hours)[END_REF]

p=0.39) or hypotension (6 (9) vs 9 (11) p=0.67) were associated with bad prognosis (Table

4

).

Table 4 :

 4 TBI patients with EVD insertion characteristics regarding their prognosis at 3 months

		Bad prognosis	Good
	Parameters	at 3 months	prognosis at 3	p-value
		(n=83)	months (n=71)
	Clinical Charateristics
	Male	61 (74)	57 (80)	0.32
	Female	22 (26)	14 (20)	0.32
	Age (years)	43 (26 to 56)	33 (23 to 48)	0,036
	SAPS II	48 (44 to 58)	39 (28 to 47)	< 0,0001
	Initial Glasgow coma score	6 (4 to 9)	8 (5 to 11.5)	0.005
	Initial motor Glasgow coma score	3 (1 to 5)	5 (3 to 6)	< 0.002
	Initial Glasgow coma scale <8	58 (70)	38 (54)	0.037
	Hypotension (Systolic Blood pressure < 90mmHg)	9 (11)	6 (9)	0.67
	Hypoxia (Oxygen stauration < 92%)	8 (10)	4 (6)	0.39
	Pupil abnormalities	29 (35)	9 (13)	0.0014
	Sedation	66 (80)	50 (70)	0.19
	PI on Transcranial Doppler > 1,4	19 (36)	24 (52)	0.1
	Intracranial hypertension under simple sedation (> 25mmHg)	78 (94)	62 (87)	0.15
	Initial intracranial pressure (mmHg)	16 (10 to 34)	18 (11 to 29)	0.86
	Secondary brain insults of systemic
	origin uncontrolled with treatment	18 (22)	13 (19)	0.63
	before EVD
	Bolus of osmotherapy before EVD	49 (59)	23 (32)	0.001
	Bolus of barbiturate before EVD	12 (15)	5 (7)	0.14
	Time from admission to EVD placement (hours)	14 (8 to 51)	24 (8 to 54)	0.43
	Failed EVD (all causes)	39 (47)	29 (41)	0.44
	Withdrawal of care	23 (28)	1 (1)	<0.0001
	Bolus of barbiturate after EVD	29 (35)	20 (29)	0.4
	Primary decompressive craniectomy	11 (13)	10 (14)	0.88
	Lenght of CSF drainage (days)	9 (4 to 16)	10 (8 to 14.5)	0.26
	Ventriculitis	5 (6)	4 (6)	0.92
	Secondary decompressive craniectomy	17 (21)	12 (17)	0.68
	In ICU mortality	43 (52)	0 (0)	<0.0001
	ICU length of stay (days)	20 (8 to 36)	24 (16.5 to 30)	0.24
	Hematoma on EVD path	2 (2)	8 (11)	0.045
	Previous EVD CT-Scan characteristics
	Traumatic Sub-Arachnoid Hemorrhage	66 (80)	52 (73)	0.36

sulci on the initial CT-scan (OR=0.3 [0.12; 0.79] p=0.014) were associated with a bad prognosis at 3 months after TBI and EVD placement.

Table 5 :

 5 Factors associated with good prognosis at 3 months after TBI with EVD insertion

	Parameters	OR	95% CI	p-value
	Clinical Charateristics
	Effacement of sulci	0.30	[0.12; 0.79]	0.014
	Age (years)	0.97	[0.94; 0.99]	0.003
	Initial Glasgow coma score	1.16	[1.04; 1.3]	0.007
	Epidural hematoma	2.91	[1.09; 7.76]	0.032
	Pupil abnormalities	0.33	[0.13; 0.84]	0.019
	OR = Odds ratio, CI = confident interval, EVD = extra ventricular drain

  Report numbers of individuals at each stage of study-eg numbers potentially eligible, examined for eligibility, confirmed eligible, included in the study, completing follow-up, and analysed

	Results
	Participants	13*	(a) 8
			(b) Give reasons for non-participation at each stage	NA
			(c) Consider use of a flow diagram	8
	Descriptive data	14*	(a) Give characteristics of study participants (eg	10
			demographic, clinical, social) and information on
			exposures and potential confounders
			(b) Indicate number of participants with missing	-
			data for each variable of interest
			(c) Summarise follow-up time (eg, average and	-
			total amount)
	Outcome data	15*	Report numbers of outcome events or summary	10
	Introduction		measures over time
	Background/rationale Main results Objectives Methods Study design Setting Participants Other analyses Discussion Key results Variables Limitations Data sources/ measurement Interpretation Bias Generalisability Study size Other information	2 16 3 4 5 6 17 18 7 19 8* 20 9 21 10	Explain the scientific background and rationale for (a) Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision the investigation being reported State specific objectives, including any prespecified (eg, 95% confidence interval). Make clear which confounders were adjusted for and why they were hypotheses included Present key elements of study design early in the (b) Report category boundaries when continuous variables were categorized paper Describe the setting, locations, and relevant dates, (c) If relevant, consider translating estimates of relative risk into absolute risk for a meaningful time including periods of recruitment, exposure, follow-period up, and data collection (a) Give the eligibility criteria, and the sources and Report other analyses done-eg analyses of subgroups and interactions, and sensitivity analyses methods of selection of participants. Describe methods of follow-up (b) For matched studies, give matching criteria and Summarise key results with reference to study objectives number of exposed and unexposed Clearly define all outcomes, exposures, predictors, Discuss limitations of the study, taking into account sources of potential bias or imprecision. Discuss potential confounders, and effect modifiers. Give both direction and magnitude of any potential bias diagnostic criteria, if applicable For each variable of interest, give sources of data Give a cautious overall interpretation of results considering objectives, limitations, multiplicity of and details of methods of assessment analyses, results from similar studies, and other (measurement). Describe comparability of relevant evidence assessment methods if there is more than one group Describe any efforts to address potential sources of Discuss the generalisability (external validity) of the study results bias Explain how the study size was arrived at	-1 3 4 NA 4 NA 4 17 NA 19 6 17 6 18 -8
	Quantitative variables Funding	11 22	Explain how quantitative variables were handled in Give the source of funding and the role of the	NA
			the analyses. If applicable, describe which funders for the present study and, if applicable, for
			groupings were chosen and why the original study on which the present article is
	Statistical methods	12	(a) Describe all statistical methods, including those based	7
			used to control for confounding
			(b) Describe any methods used to examine	-
			subgroups and interactions
			(c) Explain how missing data were addressed	-
			(d) If applicable, explain how loss to follow-up was	NA
			addressed
			(e) Describe any sensitivity analyses	-

Remerciements

Supplementary materials

Conclusion:

In a selected population of TBI with ICH requiring CSF drainage, high initial GCS was factor associated with a good functional prognosis at 3 months. Conversely, a higher age, presence of pupil abnormalities and effacement of the sulci on the initial CT-Scan were associated with bad GOS at 3 months KEY WORDS: traumatic brain injury, intracranial hypertension, cerebrospinal fluid drainage, functional prognosis