Fabien Koskas, Julien Gaudric CHU Pitié-Salpêtrière, Paris, France

1. Prevention of spinal ischemia during repair of descending (DTA) or thoracoabdominal aortic aneurysms (TAA) Fabien Koskas, Julien Gaudric CHU Pitié-Salpêtrière, Paris, France

6. PROTECTION MEDULLAIRE Clampage médullaire Hémodynamique Ischémie médullaire Hypoxie Hyperpression LCR

7. Perfusion aortique distale CEC/shunts Potentiels évoqués somesthésiques/moteur Clampage court <30mn Artifices techniques Identification groupes à risque PROTECTION MEDULLAIRE Clampage médullaire Diminution métabolisme médullaire Hypothermie profonde / péridurale Ischémie médullaire Identification et réimplantation de l’A. d’Adamkiewicz Pharmacologie (papavérine intrathécale etc…)

8. Contrôle tensionnel per op -clampage proximal -déclampage CEC Contrôle tensionnel post-op Paraplégies 2aires Contrôle pertes sanguines Cell saver, récupérateurs PROTECTION MEDULLAIRE Clampage médullaire Hémodynamique Ischémie médullaire

9. Oxygénateur/CEC PaO2 post op PROTECTION MEDULLAIRE Clampage médullaire Hémodynamique Ischémie médullaire Hypoxie exclusion pulm G

10. PROTECTION MEDULLAIRE Clampage médullaire Hémodynamique Ischémie médullaire Hypoxie Hyperpression LCR Drainage per et post opératoire

11. Personal experienceOpen surgery of DTA-TAA

12. Mechanisms of postoperative paraplegia after T(EV)AR • Reversible intraoperative spinal ischemia • Reperfusion injury • Breakdown of cellular membranes : edema • Spinal compression injury • Irreversible spinal ischemia • Permanent suppression of the spinal blood supply by the aortic procedure • Thromboembolic events within the spinal blood supply • Poor perioperative systemic hemodynamics

13. ASP ASP ASA Vascularisation médullaire ADK: D8-L2=85% Si ADK<D12: A radiculaire thor moy entre D7-D8 Kieffer E, in Techniques modernes en chirurgie vasculaire 2007 Lazorthes G et al. Arterial vascularization of the spinal cord. J Neurosurg 1971;35:253-62

14. 480 personal cases using exhaustive spinal angiograpy J Vasc Surg 2002;35:262-8.

15. AK> AK= AK? AK< Ann Vasc Surg 1989;3:34-46.

16. Risk of paraplegia/paresis after open surgical repair of TAA *Depending upon spinal arterial reattachment Ann Vasc Surg 1989;3:34-46.

17. Spinal angiography & Results

18. Risk of paraplegia/paresis after endovascular repair • Unknown • Probably globally lesser than after open surgery • Selection bias • Better perioperative hemodynamics • Conservation of collateral pathways • Very low, especially in the Ak> and Ak< groups • Not null, especially whenever Ak= or Ak?

19. Spinal angio versus spinal imaging • Exhaustive spinal angio (ESA) is our gold standard, especially for open surgery of TAAs II • ESA is technically demanding, time consuming, expensive and invasive • EVAR might require a less exhaustive evaluation : selective spinal imaging (SSI) • With modern CT technology, more and more cases can benefit from SSI without the need of another acquisition than that necessary to document the aortic lesion* * Kawaharada et al.Eur J Cardiothorac Surg 2002;21:970-4. * Yoshioka K et al. Radiographics 2003;23:1215-25

21. Principles of selective spinal imaging • Explore all intercostal arteries to be covered by the stent-graft and adjacent • With multislice CT (16 bit +), using the same acquisition as that taken for imaging the aortic lesion • With sequential catheterization only in case of a failure • Classify according to the result

22. Methods of spinal protection  • Spinal revascularization • Distal perfusion • Spinal or general hypothermia • Spinal drainage • Intrathecal or IV drugs • Papaverin, steroïds , calcium blockers, radical scavengers, barbiturates, naloxone, PGEI, allopurinol, oxygen carriers etc…

23. Spinal revascularization • Systematic and blind • Never • Selective • Size, topography and backflow of intercostal arteries • Intra-operative monitoring (evoked potentials) • Pre-operative spinal angiography

24. Distal perfusion • Improves the hemodynamic tolerance to cross-clamping • Reduces the duration of visceral and spinal ischemia

25. Methods of distal perfusion • Passive shunt • Extra-anatomic bypass • Active shunt • Cardio-pulmonary bypass • Better control of flow • Better oxygen transfer • Better control of temperature • But necessitates high doses of heparin

26. Hypothermic circulatory arrest • Visceral (and spinal) protection • Avoids difficult or hazardous cross-clamping • Dissection • Redo surgery • Inflammatory aneurysm • Eases the anastomosis by the use of an open technique • But • Bleeding • Sub-optimal myocardial protection through thoracotomy among cardiac patients

28. Methods

29. Syndrôme compartimental médullaire P(LCR) PA Ischémie Ischémie-Reperfusion PPerf Med ≈ PA(aortiquedistale) -P(LCR) • PA :  lors du clampage proximal • P(LCR) :  à cause de l’oedeme médullaire •  par phénomene de non réabsorption • Ne prend pas en compte les résistances artériolo capillaires • P veineuse Delayed onset of neurological deficit:signifiance and management.HuynhT et al.Sem in Vasc Surg 2000

30. CSF drainage does not target any other mechanism of postoperative paraplegia

31. CSF drainage is useful at reducing post-ischemic compression injury 27. Miyamoto K, Ueno A, Wada T, Kimoto S. A new and simple method of preventing spinal cord damage following temporary occlusion of the thoracic aorta by draining the cerebrospinal fluid. J Cardiovasc Surg (Torino) 1960;1:188-97. 28. Oka Y, Miyamoto T. Prevention of spinal cord injury after cross-clamping of the thoracic aorta. Jpn J Surg 1984;14:159-62. 29. McCullough JL, Hollier LH, Nugent M. Paraplegia after thoracic aortic occlusion: influence of cerebrospinal fluid drainage. Experimental and early clinical results. J Vasc Surg 1988;7:153-60. 30. Svensson LG, Grum DF, Bednarski M, et al. Appraisal of cerebrospinal fluid alterations during aortic surgery with intrathecal papaverine administration and cerebrospinal fluid drainage. J Vasc Surg 1990;11:423-9. 31. Crawford ES, Svensson LG, Hess KR, et al. A prospective randomized study of cerebrospinal fluid drainage to prevent paraplegia after high-risk surgery on the thoracoabdominal aorta. J Vasc Surg 1991;13:36-45; discussion 45-6. 32. Woloszyn TT, Marini CP, Coons MS, et al. Cerebrospinal fluid drainage and steroids provide better spinal cord protection during aortic cross-clamping than does either treatment alone. Ann Thorac Surg 1990;49:78-82; discussion 83. 33. Safi HJ, Campbell MP, Ferreira ML, et al. Spinal cord protection in descending thoracic and thoracoabdominal aortic aneurysm repair. Semin Thorac Cardiovasc Surg 1998;10:41-4. 34. Bethel SA. Use of lumbar cerebrospinal fluid drainage in thoracoabdominal aortic aneurysm repairs. J Vasc Nurs 1999;17:53-8. 35. Coselli JS, LeMaire SA, Schmittling ZC, Koksoy C. Cerebrospinal fluid drainage in thoracoabdominal aortic surgery. Semin Vasc Surg 2000;13:308-14. 36. Safi HJ, Miller CC, 3rd, Huynh TT, et al. Distal aortic perfusion and cerebrospinal fluid drainage for thoracoabdominal and descending thoracic aortic repair: ten years of organ protection. Ann Surg 2003;238:372-80; discussion 380-1. And at reversing it in some cases Garutti I, Fernandez C, Bardina A, et al. Reversal of paraplegia via cerebrospinal fluid drainage after abdominal aortic surgery. J Cardiothorac Vasc Anesth 2002;16:471-2. And several unpublished personal cases

32. Etudes randomisées Caractéristiques communes Type d’études Randomisation du drainage du LCR en chirurgie aortique thoracique. Chirurgie ouverte seulement (≠endovasculaire) Patients ATA à haut risque (type I et II) Technique Drainage LCR par ponction lombaire Autres techniques de protection équivalentes dans les groupes cas et témoin : -CEC atriofémorale -réimplantation de l’ADK Objectif Mesure du taux de parésie/paraplégie postopératoire des membres inférieurs -Crawford (JVS, 1991) -Svensson (Annals of Thoracic Surg, 1998) -Coselli (JVS, 2002)

33. Etudes randomisées -Résultats-

34. Indications du drainage Indic drainage: -ATA I,II,III et IV si réimplantation ADK Quel matériel: -Kit drainage externe du LCR. Sophysa (Tuohy 14G, KT multiperforé 60cm, poche de recueuil)

35. Indications • SSI positive • Spinal artery(ies) arising from aortic segment to be repaired • Adamkiewicz , MDA or SDA • SSI negative • No spinal artery arising from aortic segment • Surgical risk

37. SSI negative • No CSF drainage • Endovascular or open repair in peace of mind

38. SSI positive Good surgical risk Ak / MDA or SDA with large territory • Open surgery with reattachment of critical intercostal arteries using the best spinal protection methods available MDA or SDA with small territory • Give objective information to patient • If EVAR preferred, CSF drainage, spinal monitoring etc. • Retrievable stent-graft* ? • Ishimaru et al, J Thorac Cardiovasc Surg, 1998;115:811 • Midorikawa et al. Jpn J Thorac Cardiovasc Surg 2000;48:761-8

39. SSI positivePoor surgical risk • Give information to patient • EVAR if feasible • CSF drainage • Careful monitoring of systemic blood pressure • Retrievable stent-graft* under spinal monitoring ? * Midorikawa et al. Jpn J Thorac Cardiovasc Surg 2000;48:761-8& personal unpublished designs

40. Personal results with EVAR • 1996-2003 • Systematic ESA • Only 66 TEVAR cases (612 EVAR cases in the same period) • One paraparesis in one hybrid one-stepped elephant trunk under hypothermic circulatory arrest • No paraplegia

41. Conclusion • Postoperative paraplegia remains a disaster for the patient and a medicolegal concern for surgeons and radiologists • Given the low rates of paraplegia after DTA repair and the small number of patients in the series of TAA repair, efficiency of protective methods is difficult to demonstrate • The availability of SSI using CT renders blind repair of DTA or TAA questionable