Prevention of spinal ischemia during repair of descending (DTA) or thoracoabdominal aortic aneurysms (TAA)

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

PROTECTION MEDULLAIRE Clampage médullaire Ischémie médullaire Hémodynamique Hypoxie Hyperpression LCR

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

Ischémie médullaire PROTECTION MEDULLAIRE Clampage médullaire Contrôle tensionnel per op -clampage proximal -déclampage

CEC

Hémodynamique Contrôle tensionnel

post-op

Paraplégies 2 aires Contrôle pertes sanguines Cell saver, récupérateurs

PROTECTION MEDULLAIRE Clampage médullaire Ischémie médullaire Hémodynamique Hypoxie exclusion pulm G Oxygénateur/CEC PaO 2 post op

PROTECTION MEDULLAIRE Clampage médullaire Ischémie médullaire Hémodynamique Hypoxie Hyperpression LCR

Drainage per et post opératoire

Personal experience Open surgery of DTA-TAA

1990-2000 Dissection DTA % 33 8 TAA I % 12 3 TAA II % 34 8 TAA III 12 % 3 TAA IV % 1 0 Total % 92 22 Atheroma 64 15 19 4 41 10 41 10 70 16 235 55 Other Total 47 11 144 34 5 36 1 8 19 4 94 22 17 4 70 16 11 3 82 19 99 23 426 100 1990-2000 Paraplegia Paraparesis Total DTA % 2 8 1 6 144 100 TAA I 3 3 % 8 8 36 100 TAA II % 18 12 19 13 94 100 TAA III % 9 5 13 7 70 100 TAA IV % 1 1 1 1 82 100 Total % 33 29 8 7 426 100

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

ASP

Vascularisation médullaire

ASP ASA

Lazorthes G et al. Arterial vascularization of the spinal cord. J Neurosurg 1971;35:253-62

ADK: D8-L2=85% Si ADK

Kieffer E, in Techniques modernes en chirurgie vasculaire 2007

25,0% 20,0% 15,0% 10,0% 5,0% 0,0% 480 personal cases using exhaustive spinal angiograpy J Vasc Surg 2002;35:262-8.

Adamkiewicz MDA SDA

AK

> Ann Vasc Surg 1989;3:34-46.

AK< AK

=

AK

?

Risk of paraplegia/paresis after open surgical repair of TAA Type I II III IV % 15 15-40 10 10 Class Ak> Ak< Ak= Ak?

% <10 <10 5-50* 50

*Depending upon spinal arterial reattachment

Ann Vasc Surg 1989;3:34-46.

Spinal angiography & Results

1990-2000 Ak> Ak< Ak= Ak?

Total done DTA % 4 26 63 6 1 6 15 1 99 23 TAA I % 2 3 28 1 34 0 1 7 0 8 TAA II % 0 0 13 0 0 75 18 3 88 21 TAA III % 12 0 6 3 0 45 11 1 63 15 TAA IV % 23 0 17 5 5 0 4 1 45 11 Total % 41 29 228 31 329 10 7 54 7 77 1990-2000 Paraplegia Paraparesis Total DTA % 2 8 1 6 144 100 TAA I 3 3 % 8 8 36 100 TAA II % 18 12 19 13 94 100 TAA III % 9 5 13 7 70 100 TAA IV % 1 1 1 1 82 100 Total % 33 29 8 7 426 100

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?

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

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

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…

Spinal revascularization

• • •

Systematic and blind Never Selective

–

Size, topography and backflow of intercostal arteries

–

Intra-operative monitoring (evoked potentials)

–

Pre-operative spinal angiography

Distal perfusion

•

Improves the hemodynamic tolerance to cross-clamping

•

Reduces the duration of visceral and spinal ischemia

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

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

Methods

1990-2000 Xclamp CBP DHCA Total DTA % 21 5 TAA I % 0 0 TAA II % 1 0 TAA III % 3 1 TAA IV % 66 15 Total % 91 21 92 22 31 7 144 34 23 13 36 5 3 8 51 12 42 10 94 22 56 13 11 3 70 16 13 0 3 0 82 19 235 97 56 23 426 100

Syndrôme compartimental médullaire

P (LCR) PA Ischémie Ischémie-Reperfusion

PPerf Med ≈ PA (aortique distale) -P (LCR) PA :  P (LCR) :  lors du clampage proximal 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

CSF drainage does not target any other mechanism of postoperative paraplegia

27.

28.

29.

30.

31.

32.

33.

34.

35.

36.

CSF drainage is useful at reducing post-ischemic compression injury

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.

Oka Y, Miyamoto T. Prevention of spinal cord injury after cross-clamping of the thoracic aorta. Jpn J Surg 1984;14:159-62.

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.

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.

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.

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.

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.

Bethel SA. Use of lumbar cerebrospinal fluid drainage in thoracoabdominal aortic aneurysm repairs. J Vasc Nurs 1999;17:53-8.

Coselli JS, LeMaire SA, Schmittling ZC, Koksoy C. Cerebrospinal fluid drainage in thoracoabdominal aortic surgery. Semin Vasc Surg 2000;13:308-14.

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

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

)

Etude

Crawford

Drainage Etudes randomisées -Résultats Contrôle LCR vol/pression Drainage postop

14/46 (30%) 17/52 (33%) 50ml Non Svensson Coselli 2/17 (11,8%) 7/16 (43,8%) 7-10 cmH2O 48h 2/82 (2,7%) 9/74 (12,2%) <10mmHg 48h

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)

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

SSI negative

• •

No CSF drainage Endovascular or open repair in peace of mind

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.

•Ishimaru et al, J Thorac Cardiovasc Surg, 1998;115:811

Retrievable stent-graft* ?

•Midorikawa et al. Jpn J Thorac Cardiovasc Surg 2000;48:761-8

SSI positive

Poor 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

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

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