Thoracic endovascular aortic repair for traumatic aortic transection

Transcription

1 Thoracic endovascular aortic repair for traumatic aortic transection Michael R. Go, MD, Joel E. Barbato, MD, Ellen D. Dillavou, MD, Navyash Gupta, MD, Robert Y. Rhee, MD, Michel S. Makaroun, MD, and Jae-Sung Cho, MD, Pittsburgh, Pa Background: Traumatic transection of the thoracic aorta is a highly morbid injury. Treatment may be delayed while attention focuses on concomitant injuries. Thoracic endovascular aortic repair (TEVAR) is effective but remains controversial in these often-young patients. We reviewed our experience in acute and subacute treatment of these injuries with TEVAR. Methods: A retrospective analysis of five men and five women who underwent TEVAR for aortic transection from 1999 to 2007 was conducted. Procedures were performed with standard endovascular techniques. Follow-up included computed tomography at 1 month and yearly thereafter. Results: Mean age was 44 years (range, 20 to 84 years). Motor vehicle accidents accounted for 7 injuries, a snowmobile accident for 1, skydiving for 1, and balloon angioplasty of a coarctation for 1. Average diameter of the proximal landing zone was 25 mm (range, 23 to 29 mm). Mean external iliac size was 10 mm (range, 7 to 15 mm), and no conduits were required. Immediate technical success was 90%, with no 30-day mortality. Seven patients underwent repair acutely <24 ( hours) and three patients subacutely (range, 4 days to 2 months) for pseudoaneurysm. Four patients had procedures for concomitant injuries before their transection was repaired (3 laparotomies and a fixation for open fracture). One endoleak was noted, which resolved by the 1-month follow-up. The lone device-related complication was an endograft collapse at 5 months managed by repeat endografting, which was complicated by aortoesophageal fistula requiring esophagectomy and open reconstruction. No iliac injuries occurred. At 20-months of mean follow-up (range, 2 to 70 months), all patients are alive and well. Conclusions: TEVAR for traumatic aortic transection is feasible, with good initial success. Repair can be delayed in selected cases. Continued surveillance is necessary to ensure good long-term outcomes in these young patients. Care must be taken when performing TEVAR for this off-label indication because these devices are designed for the larger aortic diameters of aneurysm patients. ( J Vasc Surg 2007;46: ) Traumatic thoracic aortic transection (TAT) carries an ment can be lengthy, requires a thoracotomy with aortic overall mortality of 90%. 1 More than 80% of patients with cross-clamping, and incurs its own significant risks, which this injury die at the scene of the accident, and of those who often can be prohibitive in patients with associated head, do reach a hospital, a 1% mortality per hour has beenabdominal, and orthopedic injuries. Operative mortality described. 1 Delay in treatment for this injury is sometimes can be as high as 28%, and paraplegia affects up to 14% of necessary while diagnostic and management efforts focus patients after surgery. 5 on other injuries. In some cases, initially unrecognized Repair of these injuries with thoracic aortic stent grafts transections can progress to chronic contained perforations promises to offer a lower risk alternative to open surgery for with ongoing risk of rupture. these patients. Several case reports and small series of The main mechanism of injury in TAT is movement ofpatients with TAT treated in the acute setting with stent the mobile aortic arch against the fixed proximal descend-grafting thoracic aorta during deceleration injury, such as in acation, and mortality rates. In theory, the avoidance of have described acceptable technical success, compli motor vehicle accident or a fall. In fact, 15% of all deaths a thoracotomy and aortic cross-clamping should decrease from motor vehicle accidents are thought to result fromcomplication and death rates after aortic repair in these aortic injury, second only to the 60% caused by headcomplex, critically ill patients. injury. 3 This study reports our experience in the endovascular For nearly 50 years, open repair of TAT has been the repair of TAT performed in the acute setting as well as the 4 standard of care for this injury. Unfortunately, this treat- subacute repair of contained pseudoaneurysms after treatment of other injuries. From the Division of Vascular Surgery, Department of Surgery, University of Pittsburgh Medical School. Competition of interest: Michel S. Makaroun, MD, has a consulting agreement with W. L. Gore, Cardiomems, and Cook. He has research support from W. L. Gore, Cardiomems, Cook, Cordis, and Abbott. Reprint requests: Jae-Sung Cho, MD, Division of Vascular Surgery, University of Pittsburgh Medical Center, A1011 PUH, 200 Lothrop St, Pittsburgh, PA ( chojs@upmc.edu) /$32.00 Copyright 2007 by The Society for Vascular Surgery. doi: /j.jvs PATIENTS AND METHODS A retrospective review was conducted of all patients who underwent endovascular repair of TAT performed by the Division of Vascular Surgery at the University of Pittsburgh Medical Center between December 1999 and January Institutional Review Board approval for this study was obtained. Study variables analyzed included age, sex, mechanism of injury, associated injuries, time elapsed

2 JOURNAL OF VASCULAR SURGERY Volume 46, Number 5 Go et al 929 Table I. Associated injuries Patient Associated injury Procedures before aortic repair Time to repair 1 None None Immediate 2 Diaphragmatic rupture, pneumothorax, rib fractures None Immediate 3 Rib fractures None Immediate 4 Pelvic fracture None Immediate 5 Liver laceration, jejunal perforation, gastric Laparotomy Immediate perforation, pelvic fracture 6 Hemothorax, hemoperitoneum, femur fracture Laparotomy 1 d 7 Diaphragmatic rupture, splenic laceration Laparotomy 1 d 8 Liver laceration, pelvic fracture, pulmonary None 4 d contusion, ileal perforation 9 Liver/splenic laceration, pelvic fracture, tibia fracture Reduction and fixation of tibia 6 d 10 Liver laceration, pelvic fracture, femur fracture None 2 mon between injury and stent grafting, type and size of stentafter injury, respectively. In another patient with a stable graft, stent graft associated complications, and mortality. aortic transection and a severe liver laceration with pelvic All radiographic imaging was reviewed to identify the hemorrhage, TEVAR was delayed by 2 months at the method of diagnosis, to obtain morphologic information discretion of the referring physician (Table I). about the aortic transection, and to measure aortic and Four patients underwent operations for other acute external iliac artery diameters. life-threatening injuries before repair of their aortic transection (Table I). These operations included an exploratory In acute settings, standard advanced trauma life support protocols were used to assess patients, and life-laparotomthreatening injuries such as intraperitoneal hemorrhage tion of an open long-bone fracture in one patient. in three patients and open reduction and fixa- were addressed first. Then the transection repair was performed by using a Cook Zenith TX2 TAA EndovascularThe location of injury was at the expected anatomic loca- The diagnosis of TAT was made by CT in all patients. Graft (Cook Inc, Bloomington, Ind) or a Gore TAG Tho-tionracic Endoprosthesis (W. L. Gore & Associates Inc, Flag-A Gore TAG Thoracic Endoprosthesis was used in eight within 1 to 3 cm of the aortic isthmus, in all patients. 11 staff, Ariz) as described previously. Gore Excluder extension cuffs were used to repair the transection in one patient. in one. Two Gore Excluder extension cuffs were used in the patients and a Cook Zenith TX2 TAA Endovascular Graft No treatment delay occurred because of device unavailability in our institution. All patients were systemically hepa-two patients was in the context of a clinical investigational repair of the patient with the iatrogenic TAT. The repair in rinized with 80 U/kg and then reversed at the completionprotocol, and the rest represented off-label usage of these of the procedure. Prophylactic spinal drainage was not devices. performed. Average aortic diameter at the isthmus was 25 mm Patients underwent computed tomography (CT) angiography of the chest and four-view plain chest radiogra-30 mm, with lengths of 3 cm for the extension cuffs to 15 (range, 23 to 29 mm), and stent graft diameters were 26 to phy before discharge from the hospital, at 1 month, andcm for the longer thoracic stent grafts. Mean external iliac then yearly with an office visit. Follow-up information fordiameter of these patients was 10 mm (range, 7 to 15 mm). these patients was obtained from clinic records, and CT scans were reviewed to assess for complications such as endoleak, migration, or collapse. No conduits were required (Table II). Completion angiography revealed no endoleaks or other graft-related complications; however, one patient did have a small proximal type 1 leak at the lesser curve of the arch on predischarge CT that resolved by the 1-month follow-up. This patient accounts for an immediate technical success rate of 90%. There were no 30-day deaths. In eight cases, the stent graft was deployed distal to the left subclavian artery origin. The stent graft intentionally covered the left subclavian artery origin in two patients, and no sequelae developed as a result. No patient presented RESULTS Ten patients (5 men and 5 women) underwent thoracic endovascular aortic repair (TEVAR) for TAT during the study period. Mean age was 44 years (range, 20 to 84 years). Motor vehicle accidents accounted for seven transections, a snowmobile accident accounted for one, a skydiving injury accounted for another, and an iatrogenic injury during balloon angioplasty for an aortic coarctation with a spinal cord ischemic injury or stroke. There were no for the last. Other associated injuries are detailed in Table I. groin complications or iliac artery injuries. At a mean of 20 Time from injury to treatment varied greatly in this months of follow-up, all patients are doing well (Table II). series. Treatment was acute in seven patients, defined here A late graft-related complication occurred in a 50 yearold man whose endograft collapsed 5 months after repair. as 24 hours of injury. Late transfer from a referring hospital and a false-negative initial CT scan resulted in His aortic transection resulted from a skydiving accident delayed subacute TEVAR in two patients, at 4 and 6 days (Fig, A). At the initial repair, he was treated with a 26-mm

3 930 Go et al JOURNAL OF VASCULAR SURGERY November 2007 Table II. Operative variables and complications Variable* Value Gore TAG 8 Gore Excluder extension cuffs 1 Cook TX2 1 Mean aortic diameter, mm (range) 25 (23-29) Stent graft diameter range, mm Mean external iliac diameter, mm (range) 10 (7-15) Left subclavian covered 2 Left arm ischemia 0 Left subclavian revascularization 0 Paraplegia 0 (0) Endoleak 1 (10) Collapse 1 (10) Migration 0 (0) Iliac injury or groin complication 0 (0) Procedure related complication 1 (10) Mortality 0 (0) Mean follow up, mon (range) 20 (2-70) *Data are presented as number (%) unless indicated otherwise. W.L. Gore & Associates, Flagstaff, Ariz. Cook Inc, Cook Inc, Bloomington, Ind. treatment of degenerative aneurysmal disease, applications 10-cm TAG device because his proximal aortic neck for other pathologies are emerging, including dissections diameter measured 23 mm (Fig, B). The completion angiogram showed a small but appreciable bird s beak with-avoidance of thoracotomy, aortic cross-clamping, and left and TAT. Advantages of this application of TEVAR include out an endoleak (Fig, C). A CT scan at 3 months revealed heart or cardiopulmonary bypass, all major sources of morbidity and death after open repair. In most cases, TEVAR that the bird s beak was still present, with no endoleak or graft collapse. At 5 months from the initial repair, healso requires considerably less time than open repair and experienced new onset of chest pain and was diagnosedcan be done expediently in relatively unstable patients. with a recurrent pseudoaneurysm at the site of the original Previously published studies of stent grafting for aortic TAT secondary to endograft collapse (Fig, D). This was transection consist of case reports and small series, but all managed by a secondary extension graft. Because the trans-consistentlverse arch proximal to the left subclavian artery measureda feasible alternative to open repair. Reported immediate demonstrate that this application of TEVAR is 25 mm in diameter, a 28-mm 15-cm TAG device was technical success rate is virtually 100% in the literature, with deployed with coverage of the left subclavian artery originvery low paraplegia rates. (Fig, E). However, 1 month after the placement of this Tehrani et al 6 7 and Hoornweg et alpublished series of second stent graft, the patient presented with sepsis related30 and 28 patients, respectively, without incidence of 6,7 to aortoesophageal fistula. He ultimately underwent esophagectomy, excision of the stent grafts, and open aortictients was recently published by Neschis et al, with results procedure-related death or paralysis. A series of 20 -pa 16 replacement; fortunately, he recovered and now is doing similar to the present series. They reported one endoleak, well. This patient accounts for an overall late graft-related one graft collapse, and no procedure-related deaths, although four patients in their series died from other complication rate of 10%. injuries. DISCUSSION Traditional open repair of TAT involving thoracotomy, aortic cross-clamping, and in some cases left heart bypass is a highly invasive and morbid procedure. Respiratory compromise from lung and chest wall injuries is compounded by thoracotomy, and aortic cross-clamping and unclamping complicate pre-existing hemodynamic and cardiac instability in these critically injured patients. Paraplegia, the most feared complication of any elective thoracic aortic procedure, becomes an even more significant problem in the emergency setting of trauma. For these reasons, up to a third of trauma patients who arrive at a hospital alive with TAT die before they are 12 deemed fit for open aortic surgery. The mortality rates for 5 those who do undergo operation approach 30%. A variety of technical improvements, including the use of shunts for distal perfusion and cardiopulmonary bypass, seem to have decreased the mortality rate of this operation in some cases 13 ; but overall, open thoracic aortic surgery in these trauma victims remains a daunting undertaking. Delaying aortic repair in those who otherwise would not tolerate immediate surgery is often the only alternative. In fact, when this delay is judiciously applied, it may actually improve survival after aortic surgery in selected cases where immediate operation in a patient with other life-threatening 14,15 injuries would likely result in death. This delay, of course, comes at a cost: some patients with untreated TAT 3 may progress to exsanguination before undergoing repair. The advent of TEVAR for the treatment of TAT promises to avoid many of the complications associated with open thoracic aortic repair. It therefore may allow surgeons to offer this treatment to more critically ill aortic transection patients that previously might not have tolerated open repair and avoid having to delay repair of an injury that leaves patients in a tenuous state while uncorrected. Although TEVAR has only been approved for the Amabile et al 17 published a series of 20 patients with TAT, of whom nine were treated with TEVAR and 11 with open surgery, including direct repair or aortic replacement and cardiopulmonary bypass. The technical success rate in their endovascular group was 100%, without any procedurerelated death or morbidity, including paralysis, although one patient died after an open surgery. They concluded that the immediate outcome after endovascular aortic transection repair was at least as good as open repair. The present series also demonstrated a high immediate technical success rate, with only one procedurerelated complication. During the same time period, 43 patients underwent open repair in our institution, eight (18.6%) of whom died in the perioperative period. Care should be taken in making this comparison, however, because this is only a retrospective review of the TEVAR

4 JOURNAL OF VASCULAR SURGERY Volume 46, Number 5 Go et al 931 A, A 50-year-old man was found to have a thoracic aortic transection after a skydiving accident (arrow). B, He underwent a successful thoracic endovascular aneurysm repair with a 26-mm 10-cm TAG endoprosthesis (W. L Gore and Assoc, Flagstaff, Ariz). C, A computed tomography scan at 3 months showed a small but appreciable bird s beak without endoleak or graft collapse. The superimposed wedge symbol outlines the bird s beak. D, The patient, however, presented at 5 months with a recurrent pseudoaneurysm due to endograft collapse (arrow). E, He was treated with repeat endografting with good initial result, but ultimately required graft excision and open reconstruction for aortoesophageal fistula. patients. To our knowledge, this is the first report of the application of TEVAR for TAT in both the acute and subacute stages of injury. Thus, endovascular repair of traumatic transection seems to be a flexible treatment option that can be used immediately after injury in critically ill patients or in a delayed fashion in selected patients. However, as in the setting of endovascular repair for degenerative thoracic aneurysms, potential complications unique to stent grafting must be taken into consideration when applying this technique to repair TAT. Type 1 and type 2 endoleak associated with left subclavian coverage are well documented in the literature as are the incidences of 11,16,18-23 stent graft collapse or migration. Although no endoleaks were identified on completion arteriography in the current study, a small type 1 endoleak was detected on a postoperative CT scan that spontaneously resolved by the 1-month follow-up. The lone late graft-related complication in this series was indeed a stent graft collapse that resulted in serious complications.

5 932 Go et al JOURNAL OF VASCULAR SURGERY November 2007 Thoracic endograft collapse is often related to graft typically only in their third or fourth decade of life will need oversizing, a problem inherently associated with the smaller to be established before TEVAR can completely replace aortic diameters of relatively young trauma victims. Indeed, open aortic repair for TAT. In that regard, TEVAR may several cases of thoracic endograft collapse after TAT repairserve a role of a bridge graft in the management of TAT as have been reported. 16,20-23 The mean aortic diameter of a temporizing measure for those who develop persistent patients with traumatic aortic injury was 19.3 mm in onepseudoaneurysm or other graft-related complications. We study 24 ; however, currently available endografts in the do not yet espouse routine open conversion after TEVAR. United States do not accommodate such small aortas. The smallest TAG device accommodates a 23-mm aorta and theconclusion smallest TX2 device a 24-mm aorta. Deploying these grafts TEVAR promises to be a viable alternative to open into a small aorta inevitably results in folding of the graft surgical repair in a variety of the situations that trauma material at the proximal edge and thus poor apposition. patients often face. It can be performed with less risk of In addition, the acute angle of the transverse archexacerbating pulmonary injuries than a thoracotomy and combined with poor conformability of the grafts causes acan be completed more expeditiously in unstable patients bird s beak phenomenon in reference to the elevation ofthan open repair. Furthermore, as demonstrated by the the proximal portion of the graft from the lesser curve of current series, delayed repair can be done safely and effec- in selected patients with TAT. Continued surveillance the aorta. Vector forces exerted onto this area cause canti-tivellevering effects and may collapse the graft as observed in is needed to define long-term outcomes in this group of 25 our series. This patient did not receive an oversized device, young patients. but did have a bird s beak on completion angiogram and on a CT at 3 months. Anecdotally, it was thought that the AUTHOR CONTRIBUTIONS collapses occur early after implantation, but a review of the Conception and design: JC literature suggests that the timing of collapse is highly Analysis and interpretation: JC, MG, MM variable, ranging from days to 6 months. The timing noted Data collection: MG, JB, ED, NG, RR, JC in this series falls within the reported range. Writing the article: MG, JC Because the left subclavian artery is close to the transection, it often must be covered for an adequate proximal Critical revision of the article: JC Final approval of the article: JC sealing zone. Although this is innocuous in most cases, it Statistical analysis: MG, JC should be avoided in certain situations, such as left internal Obtained funding: Not applicable mammary-to-coronary bypass, left axillary-to-femoral bypass, or in the setting of a dominant left vertebral artery. Overall responsibility: JC Left subclavian coverage in the setting of prior aortic surgery may also increase the risk of postoperative spinal cordreferences ischemia. In such cases, left subclavian artery revascularization should be performed to preserve the anterior spinal traumatic injury of the aorta. Circulation 1958;17: Parmley LF, Mattingly TW, Manion WC, Jahnke EJ Jr. Nonpenetrating 26,27 artery and other collateral flow to the spinal cord. 2. Richens D, Field M, Neale M, Oakley C. The mechanism of injury in Smaller sizes of the aorta and external iliac arteries in blunt traumatic rupture of the aorta. Eur J Cardiothorac Surg 2002;21: this relatively young group of patients may also cause access 3. Fabian TC, Richardson JD, Croce MA, Smith JS Jr, Rodman G Jr, vessel injury or, as already mentioned, crimping of the graft Kearney PA, et al. Prospective study of blunt aortic injury: Multicenter 9,28,29 when deployed. Some authors have thus recommended aortic extension cuffs designed for use in the 1997;42: Trial of the American Association for the Surgery of Trauma. J Trauma 4. Passaro EJ, Pace WG. Traumatic rupture of the aorta. Surg 1959;46: infrarenal aorta as a smaller diameter alternative to thoracic devices designed for an aneurysm. The short lengths of 5. Cowley RA, Turney SZ, Hankins JR, Rodriguez A, Attar S, Shankar BS. these cuffs, however, often require multiple segments to Rupture of thoracic aorta caused by blunt trauma. A fifteen-year experience. J Thorac Cardiovasc Surg 1990;100: provide enough coverage, predisposing to type 3 endoleaks. 6. Tehrani HY, Peterson BG, Katariya K, Morasch MD, Stevens R, DiLuozzo G, et al. Endovascular repair of thoracic aortic tears. Ann Thorac Systemic heparinization was used in all patients in this Surg 2006;82: study for the short duration of time that the access sheaths were in place to prevent lower extremity arterial thrombosis, and it was reversed at the completion of the procedure. This did not contribute to overall significant blood loss in this series. TEVAR without heparinization has been reported 6,7 and would be indicated in the management of TAT with intracranial bleeding or other hemorrhagic injuries. The need for rigorous long-term follow-up, including multiple CT scans, can be an issue in this patient population with traditionally poor follow-up rates. Finally, the longterm durability of these stent grafts in patients who are 7. Hoornweg LL, Dinkelman MK, Goslings JC, Reekers JA, Verhagen HJ, Verhoeven EL, et al. Endovascular management of traumatic ruptures of the thoracic aorta: a retrospective multicenter analysis of 28 cases in The Netherlands. J Vasc Surg 2006;43: Orford VP, Atkinson NR, Thomson K, Milne PY, Campbell WA, Roberts A, et al. Blunt traumatic aortic transection: the endovascular experience. Ann Thorac Surg 2003;75: Peterson BG, Matsumura JS, Morasch MD, West MA, Eskandari MK. Percutaneous endovascular repair of blunt thoracic aortic transection. J Trauma 2005;59: Orend KH, Pamler R, Kapfer X, Liewald F, Gorich J, Sunder-Plassmann L. Endovascular repair of traumatic descending aortic transection. J Endovasc Ther 2002;9:573-8.

6 JOURNAL OF VASCULAR SURGERY Volume 46, Number 5 Go et al Makaroun MS, Dillavou ED, Kee ST, Sicard G, Chaikof E, Bavaria J, et al. Endovascular treatment of thoracic aortic aneurysms: results of the phase II multicenter trial of the GORE TAG thoracic endoprosthesis. J Vasc Surg 2005;41: von Oppell UO, Dunne TT, De Groot MK, Zilla P. Traumatic aortic rupture: twenty-year metaanalysis of mortality and risk of paraplegia. Ann Thorac Surg 1994;58: Jahromi AS, Kazemi K, Safar HA, Doobay B, Cina CS. Traumatic rupture of the thoracic aorta: cohort study and systematic review. J Vasc Surg 2001;34: Galli R, Pacini D, Di BR, Fattori R, Turinetto B, Grillone G, et al. Surgical indications and timing of repair of traumatic ruptures of the thoracic aorta. Ann Thorac Surg 1998;65: Pierangeli A, Turinetto B, Galli R, Caldarera L, Fattori R, Gavelli G. Delayed treatment of isthmic aortic rupture. Cardiovasc Surg 2000;8: Neschis DG, Moaine S, Gutta R, Charles K, Scalea TM, Flinn WR, et al. Twenty consecutive cases of endograft repair of traumatic aortic disruption: lessons learned. J Vasc Surg 2007;45: Amabile P, Collart F, Gariboldi V, Rollet G, Bartoli JM, Piquet P. Surgical versus endovascular treatment of traumatic thoracic aortic rupture. J Vasc Surg 2004;40: Parmer SS, Carpenter JP, Stavropoulos SW, Fairman RM, Pochettino A, Woo EY, et al. Endoleaks after endovascular repair of thoracic aortic aneurysms. J Vasc Surg 2006;44: Bavaria JE, Appoo JJ, Makaroun MS, Verter J, Yu ZF, Mitchell RS. Endovascular stent grafting versus open surgical repair of descending thoracic aortic aneurysms in low-risk patients: a multicenter comparative trial. J Thorac Cardiovasc Surg 2007;133: Muhs BE, Balm R, White GH, Verhagen HJ. Anatomic factors associated with acute endograft collapse after Gore TAG treatment of thoracic aortic dissection or traumatic rupture. J Vasc Surg Mestres G, Maeso J, Fernandez V, Matas M. Symptomatic collapse of a thoracic aorta endoprosthesis. J Vasc Surg 2006;43: Idu MM, Reekers JA, Balm R, Ponsen KJ, de Mol BA, Legemate DA. Collapse of a stent-graft following treatment of a traumatic thoracic aortic rupture. J Endovasc Ther 2005;12: Steinbauer MG, Stehr A, Pfister K, Herold T, Zorger N, Topel I, et al. Endovascular repair of proximal endograft collapse after treatment for thoracic aortic disease. J Vasc Surg 2006;43: Borsa JJ, Hoffer EK, Karmy-Jones R, Fontaine AB, Bloch RD, Yoon JK, et al. Angiographic description of blunt traumatic injuries to the thoracic aorta with specific relevance to endograft repair. J Endovasc Ther 2002;9 Suppl 2:II Demers P, Miller DC, Mitchell RS, Kee ST, Sze D, Razavi MK, et al. Midterm results of endovascular repair of descending thoracic aortic aneurysms with first-generation stent grafts [see comment]. J Thorac Cardiovasc Surg 2004;127: Gravereaux EC, Faries PL, Burks JA, Latessa V, Spielvogel D, Hollier LH, et al. Risk of spinal cord ischemia after endograft repair of thoracic aortic aneurysms. J Vasc Surg 2001;34: Khoynezhad A, Donayre CE, Bui H, Kopchok GE, Walot I, White RA. Risk factors of neurologic deficit after thoracic aortic endografting. Ann Thorac Surg 2007;83:S Milas ZL, Milner R, Chaikoff E, Wulkan M, Ricketts R. Endograft stenting in the adolescent population for traumatic aortic injuries. J Pediatr Surg 2006;41:e Sam A, Kibbe M, Matsumura J, Eskandari MK. Blunt traumatic aortic transection: endoluminal repair with commercially available aortic cuffs. J Vasc Surg 2003;38: Submitted Mar 30, 2007; accepted Jun 22, 2007.