Présentation au sujet: "Fabien Koskas, Julien Gaudric CHU Pitié-Salpêtrière, Paris, France"— Transcription de la présentation:
1Fabien Koskas, Julien Gaudric CHU Pitié-Salpêtrière, Paris, France Prevention of spinal ischemia during repair of descending (DTA) or thoracoabdominal aortic aneurysms (TAA)Fabien Koskas, Julien GaudricCHU Pitié-Salpêtrière, Paris, FranceGrateful thanks to the organizers of this meeting, I was asked to play the case against routine CSF drainage during Thoracic endovascular aortic repair
9PROTECTION MEDULLAIRE Clampage médullaireHémodynamiqueIschémiemédullaireHypoxieOxygénateur/CECPaO2 post opexclusion pulm G
10PROTECTION MEDULLAIRE Clampage médullaireHémodynamiqueIschémiemédullaireHypoxieHyperpression LCRDrainage per et post opératoire
11Personal experience Open surgery of DTA-TAA From January ninety to December 2000 four hundred twenty six patients were electively operated upon in our service for a DTA or a TAA. Twenty two percent were dissecting aneurysms. There were 144 DTAs
12Mechanisms of postoperative paraplegia after T(EV)AR Reversible intraoperative spinal ischemiaReperfusion injuryBreakdown of cellular membranes : edemaSpinal compression injuryIrreversible spinal ischemiaPermanent suppression of the spinal blood supply by the aortic procedureThromboembolic events within the spinal blood supplyPoor perioperative systemic hemodynamicsThe mechanisms of postoperative paraplegia after thoracic aortic repair, endovascular or not, are notoriously multiple :Reversible intraoperative spinal ischemiaReperfusion injury with a cascade initiated by the breakdown of cellular membranes and worsened by edema, CSF hypertension and spinal compression injuryIrreversible spinal ischemia by permanent suppression of the spinal blood flow by the aortic procedure itself or its thromboembolic consequencesAnd even poor systemic hemodynamics
13Vascularisation médullaire ASPASAADK: D8-L2=85%Si ADK<D12: A radiculairethor moy entre D7-D8Kieffer E, in Techniques modernesen chirurgie vasculaire 2007Lazorthes G et al. Arterial vascularization of the spinal cord. J Neurosurg 1971;35:253-62
14480 personal cases using exhaustive spinal angiograpy This graph shows in our personal experience of 480 cases studied before aortic repair using exhaustive spinal angiography, the probability that a certain metameric aortic level give rise to a spinal artery, with the superior dorsal in white, the middle dorsal in grey and the Adamkiewicz in black.This is one of the reasons why paraplegia has been seldom reported even after the cure of high aortic lesions like coarctation480 personal cases using exhaustive spinal angiograpyJ Vasc Surg 2002;35:262-8.
15AK> AK= AK? AK< Ann Vasc Surg 1989;3:34-46. In our institution we were lucky enough to benefit early from the collaboration of excellent neuroradiologists.This encouraged us at systematically screening all patients using exhaustive spinal angiography before thoracic aortic repair.Basically, preoperative spinal angiography helps at classifying the case into four classes of spinal risk depending whether the main spinal blood supply arises from above the lesion, below the lesion, in the middle of the lesion or is unknownAK<Ann Vasc Surg 1989;3:34-46.
16Risk of paraplegia/paresis after open surgical repair of TAA Type%ClassI15Ak><10II15-40Ak<III10Ak=5-50*IVAk?50This a summary of one of our previous works on the spinal risk after open surgery of TAA.The topographic type of the aneurysm is a recognized predictor, with a higher risk in types I and IIHowever, the class according to the level of arising of the Adamkiewicz is an even better predictor, the higher risk being observed where the adamkiewicz arises from the lesion or from an unknown level.*Depending upon spinal arterial reattachmentAnn Vasc Surg 1989;3:34-46.
17Spinal angiography & Results A spinal angiogram was obtained in 77 % of our cases. The Adamkiewicz arose above the lesion in 10 % of these, below the lesion in 7 %, at the level of the lesion in 54 % and was not seen on this spinal angiogram in seven %Even in the group of DTAs spinal arteries arose from the lesion in 15% of the cases and from an unknown part in one percent Among the 144 cases treated of a DTA, the rate of postoperative paraplegia was 1% while the rate of paraparesis was 6%.Of course, the figure is completely different for TAA cases type I and II but it is another story
18Risk of paraplegia/paresis after endovascular repair UnknownProbably globally lesser than after open surgerySelection biasBetter perioperative hemodynamicsConservation of collateral pathwaysVery low,especially in the Ak> and Ak< groupsNot null,especially whenever Ak= or Ak?What about the risk of paraplegia after endovascular repair.Despite the fact that most reports are encouraging, we must acknowledge that the risk is unknown.It is probably lower than after open surgery for several reasons :A selection bias while best candidates for EVAR are often the most limited lesionsintraoperative hemodynamics are betterEVAR conserves much of the native collateral network of the spinal blood supplyWe think that the spinal risk is especially low in the Ak above and Ak below groups.However this risk is certainly not null, especially in the groups where the spinal blood supply arises from the lesion to be covered by the graft or is unknown
19Spinal angio versus spinal imaging Exhaustive spinal angio (ESA) is our gold standard, especially for open surgery of TAAs IIESA is technically demanding, time consuming, expensive and invasiveEVAR 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*Of course it may be answered that exhaustive spinal angio which is our gold standard before open surgery is technically demanding, time consuming, expensive and at least as invasive as blind CSF drainage.We think that EVAR requires a less exhaustive spinal arterial evaluation than open surgery and allows for a shifting from exhaustive spinal angio to selective spinal imaging a concept I will explain in the next slide.With modern CT technology more and more cases can benefit from selective spinal imaging without any catheterization, using the same acquisition as that used to document the aortic lesion.* Kawaharada et al. Eur J Cardiothorac Surg 2002;21:970-4.* Yoshioka K et al. Radiographics 2003;23:
20This is a beatiful example wher the Adamkiewicz was found arising from the first lumbar artery using CT
21Principles of selective spinal imaging Explore all intercostal arteries to be covered by the stent-graft and adjacentWith multislice CT (16 bit +), using the same acquisition as that taken for imaging the aortic lesionWith sequential catheterization only in case of a failureClassify according to the resultSelective spinal imaging means that all intercostal arteries to be covered by the stent-graft and adjacent must be screenedUsing multislice CT or with selective catheter techniques only in case of a failure of CT.With our present 16 bit CT machines and algorithms more than half of the patients do not need a spinal angioIt is easy to bet that with the evolution of CT and even MRI techniques, the rate will augment in the next months or years.With selective spinal imaging, classification of a case before EVAR becomes cost effective
22Methods of spinal protection Spinal revascularizationDistal perfusionSpinal or general hypothermiaSpinal drainageIntrathecal or IV drugsPapaverin, steroïds , calcium blockers, radical scavengers, barbiturates, naloxone, PGEI, allopurinol, oxygen carriers etc…There have been several proposed methods of spinal protection, including :Spinal revascularizationDistal perfusionSpinal or general hypothermiaSpinal drainageIntra-thecal or IV drugsBut none definitely proved it’s efficiency despite some theoretical, experimental or clinical evidenceAmong the last drugs, we personally found the use of intrathecal papaverin useful
23Spinal revascularization Systematic and blindNeverSelectiveSize, topography and backflow of intercostal arteriesIntra-operative monitoring (evoked potentials)Pre-operative spinal angiographyAmong these methods of spinal protection, spinal revascularization by reimplantation of intercostal arteries seems logical and is the most popular among surgeons.Few authors choose to systematically reimplant all available intercostal arteries. Such method is difficult, time-consuming and carries a risk of intra-operative hemorrhage and late aneurysmal degeneration of the aortic buttons.There are also very few authors who never reimplant any intercostal artery and rely upon collateral circuits to provide blood supply to the spine. The situation in this case is quite different from that of stent-grafts where the efficiency of collateral circuits is not altered by the surgical approach or intra-operative hemodynamic disturbances . Such method is only tolerable when dealing with short lesions at distance from the usual aortic segments giving rise to the Adamkiewicz.Most of us use a selective approach. The choice of the intercostal arteries to reimplant may be based upon the size, the topography and the backflow of such arteries. However such method is relatively blind and carries well known risks.Intra-operative monitoring based upon evoked potentials has the definite advantage of testing the functional result of the suppression of an intercostal artery. However, such method is quite difficult to organize in our experience and needs intra-operative decision making. We therefore prefer to base selective spinal revascularization upon the findings of preoperative spinal angiography.
24Distal perfusion Improves the hemodynamic tolerance to cross-clamping Reduces the duration of visceral and spinal ischemiaDistal perfusion also contributes to spinal protection by reducing the duration of ischemia and by improving the hemodynamic tolerance to cross-clamping
25Methods of distal perfusion Passive shuntExtra-anatomic bypassActive shuntCardio-pulmonary bypassBetter control of flowBetter oxygen transferBetter control of temperatureBut necessitates high doses of heparinAmong the several methods of distal perfusion, passive shunts, extra-anatomic bypass, active shunt, cardiopulmonary bypass is the preferred choice of many because of a better control of the flow, a better oxygen transfer and a better control of temperature. However the price of this is that it necessitates high doses of heparin with a higher intra-operative bleeding
26Hypothermic circulatory arrest Visceral (and spinal) protectionAvoids difficult or hazardous cross-clampingDissectionRedo surgeryInflammatory aneurysmEases the anastomosis by the use of an open techniqueButBleedingSub-optimal myocardial protection through thoracotomy among cardiac patientsOne other advantage of cardiopulmonary bypass is that it permits the use deep hypothermia and circulatory arrest.Such method provides optimal visceral and spinal protection for long and difficult procedures and eases the making of the proximal anastomoses by the use of an open technique, without the need of proximal cross-clamping. This can be extremely helpful when dealing with pathologies where proximal control and cross-clamping is difficult and hazardous like in dissection, redo or inflammatory cases.However, circulatory arrest has definitely the cost of higher intra-operative bleeding. Also, through thoracotomy, myocardial protection relies only upon hypothermia and this may prove insufficient among cardiac patients.
27These are the two circuits that we use most often These are the two circuits that we use most often. The one one on the right, that uses the pulmonary artery is well adapted to case treated using hypothermic arrest
28Methods21 % of the cases were operated upon using simple cross-clamping. The majority of these were short DTAs or type IV TAA.. 56% were operated upon using cardio-pulmonary bypass while 23% were done using a deep hypothermic circulatory arrest.
29Syndrôme compartimental médullaire P(LCR)PAIschémie Ischémie-ReperfusionPPerf Med ≈ PA(aortique distale) -P(LCR)PA : lors du clampage proximalP(LCR) : à cause de l’oedeme médullaire par phénomene de non réabsorptionNe prend pas en compte les résistances artériolo capillairesP veineuseDelayed onset of neurological deficit:signifiance and management.HuynhT et al.Sem in Vasc Surg 2000
30CSF drainage does not target any other mechanism of postoperative paraplegia However it must be pointed out that CSF drainage does not target any other mechanism of postoperative paraplegia than compression injury after reversible ischemia and reperfusion
31CSF 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;1:28. Oka Y, Miyamoto T. Prevention of spinal cord injury after cross-clamping of the thoracic aorta. Jpn J Surg 1984;14:29. 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;7:30. 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;13:36. 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; discussionThere is a maze of literature, with certain titles going back to the sixties, proving that CSF drainage is useful at reducing post-ischemic compression injury. Among this literature there is even a quite convincing prospective randomized trial proving this usefulness during open surgery. There are also some papers and several unpublished evidences that CSF drainage can reverse some cases of postoperative paraplegia or paresis.And at reversing it in some casesGarutti 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
32Caractéristiques communes Etudes randomiséesCaractéristiques communesType d’étudesRandomisation du drainage du LCR en chirurgie aortique thoracique.Chirurgie ouverte seulement (≠endovasculaire)PatientsATA à haut risque (type I et II)TechniqueDrainage LCR par ponction lombaireAutres techniques de protection équivalentes dans les groupes cas et témoin :-CEC atriofémorale-réimplantation de l’ADKObjectifMesure du taux de parésie/paraplégie postopératoire des membres inférieurs-Crawford (JVS, 1991)-Svensson (Annals of Thoracic Surg, 1998)-Coselli (JVS, 2002)
34Indications du drainage Indic drainage:-ATA I,II,III et IV si réimplantation ADKQuel matériel:-Kit drainage externe du LCR. Sophysa(Tuohy 14G, KT multiperforé 60cm, poche de recueuil)
35Indications SSI positive SSI negative Surgical risk Spinal artery(ies) arising from aortic segment to be repairedAdamkiewicz , MDA or SDASSI negativeNo spinal artery arising from aortic segmentSurgical riskSSI is considered positive if spinal arteries arise from the aortic segment to be covered and negative in the contrary.It is also important to know if it is the artery of Adamkiewicz or a dorsal artery that arises from the critical aortic segment.Of course the general class of surgical risk of the patient is to be considered to take the indication
36In this clear cut example of a 26 years old patient with this large intercostal arising from the aneurism and giving rise the artery of Adamkiewicz We did not take the risk of EVAR even with the protection of CSF drainage.The patient was operated openly with reattachment of the intercostal artery.Follow-up was uneventful
37SSI negative No CSF drainage Endovascular or open repair in peace of mindWhen SSI is negative, EVAR is proposed in peace of mind and without CSF drainage
38SSI positive Good surgical risk Ak / MDA or SDA with large territoryOpen surgery with reattachment of critical intercostal arteries using the best spinal protection methods availableMDA or SDA with small territoryGive objective information to patientIf EVAR preferred, CSF drainage, spinal monitoring etc.Retrievable stent-graft* ?Whenever SSI is positive in a good surgical risk patient, and the critical artery is the Adamkiewicz or has a large metameric territory we prefer open surgery with reattachment of critical intercostal arteries and the best available methods of spinal protection, distal perfusion, CSF drainage, papaverin or hypothermia.There is however a discussion if the critical spinal artery is a MDA or a SDA with a small territory.In this case, we think it is extremely important to give unbiased information to the patient.If EVAR is preferred, it is of course done with CSF drainage and the best available methods of spinal monitoring.It is perhaps in these situations that the concept of a retrievable stent-graft is appealingIshimaru et al, J Thorac Cardiovasc Surg, 1998;115:811Midorikawa et al. Jpn J Thorac Cardiovasc Surg 2000;48:761-8
39SSI positive Poor surgical risk Give information to patientEVAR if feasibleCSF drainageCareful monitoring of systemic blood pressureRetrievable stent-graft* under spinal monitoring ?When SSI is positive in a poor risk patient, we follow a similar pattern.Systemic blood pressure control is of a paramount importance in these cases.CSF drainage is of course routinely used.Like others, we develop currently a retrievable stent-graft, using the same technologies as those employed for our custom–made designs.These retrievable implants could be inserted on awake patient or under any method of spinal monitoring like evoked potentials.* Midorikawa et al. Jpn J Thorac Cardiovasc Surg 2000;48:761-8 & personal unpublished designs
40Personal results with EVAR Systematic ESAOnly 66 TEVAR cases (612 EVAR cases in the same period)One paraparesis in one hybrid one-stepped elephant trunk under hypothermic circulatory arrestNo paraplegiaWith this general pattern of indications, we treated only 66 cases using EVAR since 1996 without any case of paraplegia but one paraparesis of two months after one complex procedure including a one-stepped stented elephant trunk through sternotomy under hypothermic circulatory arrest for type B dissection
41ConclusionPostoperative paraplegia remains a disaster for the patient and a medicolegal concern for surgeons and radiologistsGiven 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 demonstrateThe availability of SSI using CT renders blind repair of DTA or TAA questionable