Endovascular Repair of Thoracic Aortic Tears

Transcription

1 Endovascular Repair of Thoracic Aortic Tears Hassan Y. Tehrani, MB, ChB, Brian G. Peterson, MD, Kushagra Katariya, MD, Mark D. Morasch, MD, Randy Stevens, MD, Gabrielle DiLuozzo, MD, Tomas Salerno, MD, Giuseppe Maurici, RT, Darwin Eton, MD, and Mark K. Eskandari, MD Department of Surgery, University of Miami/Jackson Memorial Hospital, Miami, Florida, Division of Vascular Surgery, Northwestern Memorial Hospital, Chicago, Illinois, and Department of Cardiothoracic, Surgery Mt. Sinai Medical Center, New York, New York CARDIOVASCULAR Background. Standard treatment of traumatic thoracic aortic transection (TTAT) is open repair by left thoracotomy with or without the use of partial cardiopulmonary bypass. However, open repair is associated with high rates of morbidity and mortality, particularly in multiply injured trauma patients. We reviewed our experiences of endovascular repair of acute TTAT. Methods. Between February 2001 and February 2006, 30 patients (male 24, female 6, mean age 43 years) who had sustained severe blunt trauma with multiple injuries (mean injury severity score 42) underwent endovascular repair for TTAT. Devices used included commercially available proximal abdominal aortic extension cuffs and thoracic stent-grafts. Either low dose or no systemic heparin was used. Arterial access was obtained by femoral-iliac cutdown (n 19) or completely percutaneous through the femoral artery (n 11). Mean follow-up was 11.6 months (range, 1 to 48 months). Results. Technically success was achieved in 100% of patients, as determined by angiographic and computed tomographic (CT) scan exclusion of TTAT. Mean operating time was 132 minutes. Mean blood loss was 300 cm 3. Three patients had complications: 1 iliac artery rupture, 1 cerebellar stroke, and 1 partial stent collapse. There were 2 perioperative deaths. There were no instances of procedure-related paralysis. Clinical and CT follow-up did not reveal evidence of endoleak, stent migration, or late pseudoaneurysm formation. Conclusions. The adaptation of commercially available stent-graft devices to treat TTAT is technically feasible, and can be performed with low rates of morbidity and mortality. The long-term durability of endovascular repair of TTAT remains unknown, but early and midterm results appear promising. (Ann Thorac Surg 2006;82:873 8) 2006 by The Society of Thoracic Surgeons Thoracic aortic injury carries a mortality rate of over 90%, with 80% of these individuals dying at the scene. The landmark study by Parmley and colleagues [1], published in 1958, documented a mortality rate at the scene of as high as 85% and a subsequent mortality rate in nonoperated survivors of 1% per hour for the first 48 hours. Aortic injuries are responsible for the cause of death of up to 15% of all deaths after motor vehicle accidents [2]. In 1959, Passaro and Pace [3] described the first successful primary repair of an acute traumatic thoracic aortic transection (TTAT) performed by Klassen the previous year. Since that time, open surgical repair has remained the standard treatment for TTAT. However, conventional open repair with interposition grafting mandates left thoracotomy, single lung ventilation and aortic cross-clamping, with or without the adjunct use of partial cardiopulmonary bypass and systemic heparinization. Several studies have demonstrated mortality rates ranging from 5% to 28% after open repair, and paraplegia rates secondary to spinal cord ischemia ranging from 2.3% to 14% [4 8]. Patients with TTAT nearly always have associated severe multiple injuries, and as a consequence are often in extremis on presentation, which adds to the complexity of performing open surgery. Currently, there are no specifically designed, commercially available devices used to treat TTAT. Since the mid-1990s there have been a number of case series demonstrating the feasibility of endovascular repair of TTAT using either abdominal aortic extension cuffs or stent-grafts designed to treat thoracic aneurysms [9 17]. The advantages of this treatment modality include the avoidance of thoracotomy, single lung ventilation, aortic cross-clamping, cardiopulmonary bypass, and systemic heparinization in these multiply injured patients. The purpose of this study was to demonstrate that Accepted for publication April 3, Presented at the Forty-second Annual Meeting of The Society of Thoracic Surgeons, Chicago, IL, Jan 30 Feb 1, Address correspondence to Dr Tehrani, University of Miami/Jackson Memorial Hospital, Department of Surgery, 1611 NW. 12th Ave., ET 3016, Miami, FL 33136; htehrani@med.miami.edu. Dr Morasch discloses a financial relationship with W. L. Gore and Associates, Inc, Abbott Vascular, Berlex, Inc, and King Pharmaceuticals; and Dr Eskandari with Guidant, Cordis, Abbott Vascular Devices, and W. L. Gore and Associates, Inc by The Society of Thoracic Surgeons /06/$32.00 Published by Elsevier Inc doi: /j.athoracsur

2 CARDIOVASCULAR 874 TEHRANI ET AL Ann Thorac Surg ENDOVASCULAR REPAIR OF THORACIC AORTIC TEARS 2006;82:873 8 Fig 1. Traumatic thoracic aortic tear prior to repair. TTAT in the setting of blunt trauma can be treated using endoluminal stent-grafts. We report our two center experience of endovascular repair of acute TTAT. Patients and Methods We performed a retrospective analysis of all patients undergoing endovascular repair of TTAT between February 2001 and February 2006 at Northwestern Memorial Hospital (NMH), Chicago Illinois and Jackson Memorial Hospital (JMH), Miami Florida. At both institutions, the respective Institutional Review Boards approved the study and waived the need for patient consent. All patients were involved in high-speed motor vehicle collisions or rapid deceleration events and suffered multiple injuries. These patients underwent endovascular of TTAT in the acute setting. Mechanism of injury or abnormalities seen on initial chest radiograph in the setting of blunt trauma (including widened mediastinum, obliteration of the aortic knob, tracheal deviation to the right, left hemothorax, depression of the left main stem bronchus, presence of a pleural or apical cap, widened paratracheal stripe, or fractures of the first rib or scapula) mandated further workup with a chest computed tomographic (CT) scan (Fig 1). In all cases, patients with radiographic evidence of thoracic aortic injuries underwent immediate endovascular repair. The rapidity with which the endovascular repair could be performed did not significantly delay surgical treatment of concomitant injuries (ie, laparotomy or craniotomy). Thoracic aortic transection suggested by CT was confirmed in all cases with intraoperative aortography. There were no cases in which an aortic transection was suggested by CT but could not be elucidated at the time of angiography. Measurements of the proximal and distal neck length and aortic diameter, as well as location and extent of injury in relation to the origins of the arch vessels, were obtained using the aforementioned imaging modalities. All procedures were performed either in a purposebuilt operating room angiosuite or regular operating room with c-arm fluoroscopy. The devices used consisted of either commercially available endovascular aortic proximal extension cuffs (AneuRx, Medtronic/AVE, Santa Rosa, CA; Excluder, W.L. Gore & Associates, Flagstaff, AZ), or thoracic aortic stent-grafts (TAG, W.L. Gore & Associates, Flagstaff, AZ; Braile Biomedica stent-graft, Braile Biomedica, SJ Rio Preto, Sao Paulo, Brazil) (Table 1). After induction of general anesthesia, access to the aorta was obtained through the common femoral artery in 28 patients (93%) (19 by a cut-down and 11 percutaneous) or by a cut-down on the iliac artery in 2 patients (7%). A floppy tipped J-wire was then passed into the aorta under direct fluoroscopic guidance through a 6 French sheath. An aortogram was obtained using steep left anterior oblique projection so as to open up the aortic arch. Arch anatomy and location of the aortic transection were noted. In those patients undergoing percutaneous repair, a 10 French Perclose device (Perclose/Abbott Labs, Redwood City, CA) was then deployed using the previously described preclose technique [19]. The floppy wire was then exchanged for a super-stiff wire. Over this wire, and depending on the stent-graft used, an 18 to 22 French sheath was exchanged and passed proximally into the thoracic aorta. This larger sheath was used to deliver the endovascular graft, which was placed over the area of transection and deployed without the use of chemically induced cardiac arrest or hypotension. After deployment, angiograms were performed and additional stent-grafts were placed as needed. Compliant aortic occlusion balloons were selectively used to obtain stentgraft apposition to the aortic wall if an endoleak was noted. Either low dose or no systemic heparin was used. The diameter of the devices used was based upon previously recorded measurements of the aortic lumen diameter by CT scan performed preoperatively. The devices were oversized by approximately 20%. In most cases the size of the aorta was too small for an available thoracic stent-graft. Therefore, approximately 75% of our patients received an endovascular repair with multiple overlapping smaller diameter abdominal aortic proximal extension cuffs. In four patients, preoperative CT scan demonstrated the area of transection to be in close proximity to the origin of the left subclavian artery, from which the dominant vertebral artery took its origin. In order to ensure an adequate seal proximal to the transection in this patient, the left subclavian artery was transposed to the left common carotid artery prior to endovascular repair. The origin of the left subclavian artery was then covered with the stent-graft. After endovascular repair, patients underwent CT angiography within one month postrepair and at 6- to 12-month intervals thereafter. Table 1. Types of Endografts Used for Repair Device No. (%) Excluder 20 (66.6%) AneuRx 1 (3.3%) TAG 6 (20%) Braile 2 (6.6%) Excluder AneuRx 1 (3.3%)

3 Ann Thorac Surg TEHRANI ET AL 2006;82:873 8 ENDOVASCULAR REPAIR OF THORACIC AORTIC TEARS Table 2. Patient Summary Including Sex, Age, Device Type, Injury Severity Score (ISS), Periprocedural Complications, and Associated Injuries Sex Age Device ISS Complications Associated Injuries 875 CARDIOVASCULAR M 51 Excluder 35 Femur fx M 40 Excluder 34 Rib fx, pulm contusion F 41 AneuRx 41 Pelvis/femur/rib fx, pulm contusion M 42 Excluder 66 SAH, spinal cord injury, fx, pulm contusion F 40 Excluder 66 CHI, C/T/L spine fx M 50 Excluder 25 Rib fx, pulm contusion F 20 Excluder 41 Femur fx, ankle dislocation M 73 Excluder 38 Midface/pelvis/wrist fx M 26 Excluder 38 Left PCA stroke Tibial fx, knee dislocation F 47 Excluder 45 Lumbar spine/rib fx, pulm contusion M 43 Excluder 38 Rib/pelvis fx, pulm contusion, hemothorax M 22 TAG 66 Device collapse T-spine fx, spinal cord injury, CHI M 28 Excluder 34 C-spine fx, spinal cord injury M 59 TAG 41 SAH, pelvis/femur fx, pulm contusion M 66 TAG 25 Pulm contusion M 28 Excluder 25 Rib fx, pulm contusion M 36 Exc Anrx 45 Pelvis/femur fracture fx, CHI M 35 Braile 33 Pelvis/rib fx, pulm contusion, kidney injury M 32 Excluder 57 Humerus/pelvis fx, bladder rupture M 33 Excluder 33 Pelvis fx, liver laceration M 29 Excluder 35 EIA rupture SDH, nasal fx M 82 Excluder 29 Small bowel injury M 40 Excluder 29 C-spine fx M 45 TAG 26 Facial laceration M 42 Braile 26 Facial laceration F 67 Excluder 59 Death Pelvis/c-spine fx, bladder rupture M 21 Excluder 36 Liver/spleen injury M 21 Excluder 41 Liver/spleen/pancreas injury F 71 TAG 33 Clavicle fx, pneumothorax, splenic injury M 72 TAG 41 Death SDH, mandible/pelvis/femur fx, diaphragm rupture M male; F female; Excluder/AneuRx/Exc/Anrx aortic extension cuffs; TAG Gore thoracic endoprosthesis; PCA posterior cerebral artery, EIA external iliac artery, Fx fracture, Pulm pulmonary, SAH subarachnoid hemorrhage, CHI closed head injury, C/T/L cervical/thoracic/lumbar, SDH subdural hematoma. Results The average patient age in this study was years (range, 20 to 82), with 24 (80%) males and 6 (20%) females. Sixteen cases were performed at NMH, 14 at JMH. Patients suffered multiple injuries including the following: closed head injury, rib fractures with concomitant pulmonary contusion, extremity or pelvic fractures, and solid organ injury (Table 2). The mean injury severity score (ISS) of this group of patients was (range, 25 to 66). The mechanisms of injury included high-speed motor vehicle collisions (28 patients), a fall from a threestory building (1 patient), and a pedestrian versus automobile accident (1 patient). Technical success was achieved in 100% of patients and was defined by angiography and CT scan demonstrating exclusion of TTAT. Angiography demonstrated apposition of the stent-grafts to the aortic wall, normal perfusion of the aortic arch vessels, and exclusion of the aortic transection without evidence of extravasation of contrast in all cases. The mean operating time was 132 minutes and mean blood loss was 300 cm 3. There were three procedure-related complications (10%): 1 (3.3%) cerebellar stroke, 1 (3.3%) iliac artery rupture, and 1 (3.3%) partial stent collapse necessitating return to the operating room for additional stent placement. There were 2 (6.6%) early deaths at 16 and 24 days postprocedure. These multiply injured patients were aged 72 and 67, respectively. Both patients developed multisystem organ failure, and in view of their advance age, comorbidities, and injuries, supportive care was withdrawn. There were no instances of procedure-related paralysis. Despite receiving contrast dye loads for preoperative CT imaging and at the time of endovascular repair, no patient suffered contrast-induced nephropathy. Mean follow-up of this patient cohort was 11.6 months (range, 1 to 48 months). Clinical and CT follow-up did not reveal evidence of endoleak, stent migration, or late pseudoaneurysm formation (Fig 2).

4 CARDIOVASCULAR 876 TEHRANI ET AL Ann Thorac Surg ENDOVASCULAR REPAIR OF THORACIC AORTIC TEARS 2006;82:873 8 Fig 2. Traumatic thoracic aortic tear after endovascular repair. Comment Traumatic aortic transection occurring as a result of blunt trauma leads to immediate death in over 80% of cases. Those patients that survive often have associated multiple and severe injuries. Since the description by Parmley and colleagues [1] of the high mortality in nonoperated patients, the standard of care for TTAT has been early surgical repair. Despite advances in cardiac anesthesia and refinement of surgical techniques and perfusion systems, the morbidity and mortality of early operative repair of TTAT remains high. While some groups have advocated delay in the surgical treatment of TTAT in stable patients with close arterial pressure monitoring, the theoretical advantages of this strategy are negated when considering that 2% to 5% of these patients develop secondary rupture, most within one week of the initial injury [20 22]. All patients in this series underwent immediate endovascular repair after radiographic evidence of aortic injury. This did not significantly delay the surgical intervention of concomitant injuries when necessary. Since the initial report describing endovascular treatment of thoracic aortic pathology with stent-grafts by Kato and colleagues [10], several subsequent case reports have demonstrated the technical feasibility of this technique [11 18]. As our report shows, we have demonstrated that TTAT can be safely and effectively treated using a variety of endovascular stent-grafts. Early in our experience we used off-the-shelf commercially available endovascular aortic proximal extension cuffs. More recently we have been using endografts originally intended to treat thoracic aneurysms. Currently, there are no endografts available that have been designed specifically to treat TTAT. Those designed to treat thoracic aneurysms are available in a range of diameters, the smallest of which is usually too oversized to be deployed in patients with TTAT, who invariably have smaller sized aortas. Excessive oversizing of the endograft diameter in relation to the native aorta may have been responsible for the device collapse as seen in one of our patients, and has been described elsewhere [23]. The smallest commercially available device designed for use in the thoracic aorta has a diameter of 26 mm. This device is intended for aortas at least 23 mm in diameter according to the manufacturer s instructions for use. In many cases, this device size limitation necessitated the use of aortic extension cuffs designed for use in the infrarenal aorta in an off-label fashion to prevent oversizing in smaller aortas. Endovascular repair of TTAT has clear advantages over open surgery, avoiding left thoracotomy, single lung ventilation, systemic heparinization, and cardiopulmonary bypass in often critically injured patients. As seen in our study, operative times and mean blood loss are lower than might be expected with conventional surgery. We had no instances of procedure-related paraplegia: the elimination of aortic cross-clamping with this technique may theoretically completely avoid this dreaded complication. While a direct comparison between patients undergoing either endovascular or conventional repair of blunt aortic injuries would be ideal, there was only one patient treated by open repair during this time period (due to lack of an available stent), making this comparison impossible. The infrequency with which these injuries occur makes a comparison of treatment modalities difficult. Three small series have attempted to make this comparison. Kasirajan and colleagues [24] treated five patients suffering traumatic aortic transection endoluminally and reported significantly lower mean procedural time, length of hospital stay, and perioperative mortality in comparison with open repair controls. A year later, Ott and colleagues [25] reported their experience of 18 patients with blunt thoracic aortic injuries and demonstrated a mortality rate of 17%, paraplegia rate of 16%, and recurrent laryngeal nerve injury rate of 8.3% in patients undergoing open repair. The five patients in the endovascular group had no deaths, paraplegia, or recurrent nerve injuries. More recently, Amabile and colleagues [26] treated twenty patients with traumatic thoracic aortic rupture over a six year period. Nine of these patients underwent endovascular repair and the remaining 11 had open repair. There was one intraoperative death in the open repair group, and no deaths, paraplegia, or procedural-related complications in the endovascular group. Endovascular repair was technically successful in each case, demonstrating endovascular repair to be at least as good as conventional open repair in the immediate perioperative period with the need for longer follow-up. The average age of patients with TTAT is lower than that of patients who present with aneurysmal disease and the long-term outcome and durability of these endovascular devices has yet to be proven. As such, follow-up still requires annual CT angiography. To date, we have no instances of endoleak, stent migration, or late pseudoaneurysm formation. As these devices are not required to bridge a fusiform aneurysm, and are placed over a short distance within an otherwise normal aorta, the occurrence of late complications like those seen after endovascular repair of abdominal or thoracic aortic aneurysms may be less frequent. If device-related problems did occur in follow-up, and if conversion to open surgery

5 Ann Thorac Surg TEHRANI ET AL 2006;82:873 8 ENDOVASCULAR REPAIR OF THORACIC AORTIC TEARS was required, it could likely be performed under more elective circumstances and in a healthier patient. In summary, our series, the largest series reported in the literature to date, demonstrates that the adaptation of commercially available stent-graft devices to treat TTAT is technically feasible, and can be performed with low rates of morbidity and mortality. The long-term durability of endovascular repair of TTAT remains unknown, but early and midterm results appear promising. Dr Morasch received research support from W. L. Gore and Associates, Inc; Guidant, Corp; Cook, Inc; and Medtronic. Dr Tehrani received a research grant from W. L. Gore and Associates, Inc. References 1. Parmley LF, Mattingly TW, Manion WC, Jahnke EJ Jr. Nonpenetrating traumatic injury of the aorta. Circulation 1958;17: Williams JS, Graff JA, Uku JM, Steinig JP. Thoracic aortic injury in vehicular trauma. Ann Thorac Surg 1994;57: Passaro E, Pace WG. Traumatic rupture of the aorta. Surgery 1959;46: Lobato AC, Quick RC, Phillips B, et al. Immediate endovascular repair for descending thoracic aortic transection secondary to blunt trauma. J Endovasc Ther 2000;7: Cowley RA, Turney SZ, Hankins JR, Rodriguez A, Attar S, Shankar BS. Rupture of thoracic aorta caused by blunt trauma: a fifteen-year experience. J Thorac Cardiovasc Surg 1990;100: Gott VL. Heparinized shunts for thoracic vascular operations. Ann Thorac Surg 1972;14: Verdant A. Traumatic rupture of the thoracic aorta. Ann Thorac Surg 1990;49: von Oppell UO, Dunne TT, De Groot MK, Zilla P. Traumatic aortic rupture: twenty-year meta-analysis of mortality and risk for paraplegia. Ann Thorac Surg 1994;58: Dake MD, Miller DC, Semba CP, Mitchell RS, Walker PJ, Liddell RP. Transluminal placement of endovascular stentgrafts for the treatment of descending thoracic aortic aneurysms. N Engl J Med 1994;331: Kato N, Dake MD, Miller DC, et al. Traumatic thoracic aortic aneurysm: treatment with endovascular stent-grafts. Radiology 1997;205: Sam A 2nd, Kibbe M, Matsumura J, Eskandari MK. Blunt traumatic aortic transection: endoluminal repair with commercially available aortic cuffs. J Vasc Surg 2003;38: Wellons ED, Milner R, Solis M, Levitt A, Rosenthal D. Stent-graft repair of traumatic thoracic aortic disruptions. J Vasc Surg 2004;40: Dunham MB, Zygun D, Petrasek P, Kortbeek JB, Karmy- Jones R, Moore RD. Endovascular stent grafts for acute blunt aortic injury. J Trauma 2004;56: Semba CP, Kato N, Kee ST, et al. Acute rupture of the descending thoracic aorta: repair with use of endovascular stent-grafts. J Vasc Interv Radiol 1997;8: Ahn SH, Cutry A, Murphy TP, Slaiby JM. Traumatic thoracic aortic rupture: treatment with endovascular graft in the acute setting. J Trauma 2001;50: Peterson BG, Matsumura JS, Morasch MD, West MA, Eskandari MK. Percutaneous endovascular repair of blunt thoracic aortic transection. J Trauma 2005;59: Rousseau H, Dambrin C, Marcheix B, et al. Acute traumatic aortic rupture: a comparison of surgical and stent-graft repair. J Thorac Cardiovasc Surg 2005;129: Peterson BG, Longo GM, Matsumura JS, et al. Endovascular repair of thoracic aortic pathology with custom-made devices. Surgery 2005;138: Morasch MD, Kibbe MR, Evans ME, et al. Percutaneous repair of abdominal aortic aneurysm. J Vasc Surg 2004;40: Pierangeli A, Turinetto B, Galli R, Caldarera L, Fattori R, Gavelli G. Delayed treatment of isthmic aortic rupture. Cardiovasc Surg 2000;8: Fabian TC, Richardson JD, Croce MA, et al. Prospective study of blunt aortic injury: multicenter trial of the American Association for the Surgery of Trauma. J Trauma 1997;42: Holmes JH IV, Bloch RD, R. Hall RA, Carter YM, Karmy- Jones RC. Natural history of traumatic rupture of the thoracic aorta managed nonoperatively: a longitudinal analysis. Ann Thorac Surg 2002;73: 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: Kasirajan K, Heffernan D, Langsfeld M. Acute thoracic aortic trauma: a comparison of endoluminal stent grafts with open repair and nonoperative management. Ann Vasc Surg 2003; 17: Ott MC, Stewart TC, Lawlor DK, Gray DK, Forbes TL. Management of blunt thoracic aortic injuries: endovascular stents versus open repair. J Trauma 2004;56: 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: CARDIOVASCULAR DISCUSSION DR R. MORTON BOLMAN III (Boston, MA): What was the average length of stent that you used, and what was the average diameter? DR TEHRANI: We typically overlap three or four cuffs, which are only about 3-1/2 cm long each, but you have to have a certain degree of overlap to avoid endoleak. We didn t actually measure the length, but it probably lies somewhere between 7 and 10 cm. DR BOLMAN: And the size? DR TEHRANI: Typically these patients are younger, healthier, and they have a aortic diameter that s around about 20 to 22, so we put in 23 mm cuffs or 26 mm cuffs. DR GRAYSON H. WHEATLEY (Phoenix, AZ): Dr Tehrani, I want to complement you on an excellent presenting and for performing a very important study. However, I had a few questions. First of all, what was your strategy in deciding who received an endoluminal graft for the treatment of their traumatic aortic transection, and during that same period of time over the four year period, can you estimate what percentage of patients underwent surgical repair versus medical management versus endovascular repair? I am just interested in your strategy on who received this therapy. And second, I wanted to also ask your comments on who received heparin during their endovascular intervention. Part of the controversy is that here you are potentially heparinizing a patient with an acute multisystem trauma, and what is your

6 CARDIOVASCULAR 878 TEHRANI ET AL Ann Thorac Surg ENDOVASCULAR REPAIR OF THORACIC AORTIC TEARS 2006;82:873 8 strategy in terms of measuring coagulation profiles, or what was your cutoff in determining anticoagulation in those patients? Thank you very much. DR TEHRANI: Thank you Dr Wheatley. In answer to your first question, after our first case using a stent-graft we were so impressed with the result that we continued using this strategy in patients with this problem. We haven t really performed any open surgical cases except in one patient, and the only reason why performed open surgery was because we didn t have any stent-grafts available to us. My colleagues at Northwestern, have taken the same approach: They haven t performed any open repairs since they have started using stent-grafts. With regards to your next question about the heparinization, I know my colleagues at Northwestern have performed most of their cases without heparin. I tend to give a couple of thousand units to keep the ACT around about 200. However, if the patient has a known head injury, obviously I don t give any heparin. It really depends on the patient and the surgeon preference. The concern about not giving heparin is once you have the wire across the aortic arch, it is a nidus for thrombus formation, and that you may have a higher incidence of stroke. DR JOHN ELEFTERIADES (New Haven, CT): Congratulations on a very fine presentation, and I have a fundamental question for you. Our understanding of this disease has changed a lot in the last two decades, and we are realizing now that many of these patients can heal these tears on their own. My question to you is, do you think these patients might have healed on their own, and in particular, how many were done outside of the immediate acute period, say a day or two or three days later, when they had proven that they had not ruptured? DR TEHRANI: All of these patients surgeries were performed in the acute setting; pretty much done as soon as the diagnosis was made. I understand your concerns about waiting to see whether these tears heal up: there is always going to be the worry that you are going to sit on these patients that are at risk of rupture and a lot of times we don t know which ones will and which ones won t. We had a couple of patients that we did wait on and they did rupture. But those patients were actually turned down for surgery, and even for endovascular graft placement, because they had such severe other injuries that it was felt that they would not survive. I think if the patient has a small intimal tear, with small pseudoaneurysm then it is reasonable to not intervene except for blood pressure and heart rate control. But I feel that once you see a lot of hematoma in the mediastinum, then you should push to have them treated. DR JOSEPH S. COSELLI (Houston, TX): Very nice presentation. I am just curious about a few of the aspects of the treatment of these patients that you didn t mention, and that is, your thoughts on the use of IVUS routinely and transesophageal echocardiography. It is quite notable that you had no incidence of paraplegia, and so what would your thoughts be on the use of CSF [cerebrospinal fluid] drainage in this population? DR TEHRANI: Thank you Dr Coselli. With regards to the use of intraoperative IVUS [intravascular ultrasound] and TEE [transesophageal echocardiography], we don t really really use it. We confirm our diagnosis with the thoracic aortogram. We only use TEE to look at cardiac function, not to look at the tear or for stent-graft placement. With regards to your next question about spinal cord drainage. We are covering only a short segment of the proximal descending thoracic aorta, and there is no cross-clamping. We occasionally inflated an occlusion balloon for a few seconds to tack up the proximal and distal portions of the stent. Looking at the literature: in other case series, although they are only small numbers, I haven t found a single instance where there has been device or procedure related paraplegia when this procedure has been done for this indication. I think it just won t happen, again, because you are covering such a short segment of the aorta and you are not cross clamping. Notice From the American Board of Thoracic Surgery The 2006 Part I (written) examination will be held on Monday, December 4, It is planned that the examination will be given at multiple sites throughout the United States using an electronic format. The closing date for registration is August 1, Those wishing to be considered for examination must apply online at To be admissible to the Part II (oral) examination, a candidate must have successfully completed the Part I (written) examination. A candidate applying for admission to the certifying examination must fulfill all the requirements of the Board in force at the time the application is received. Please address all communications to the American Board of Thoracic Surgery, 6333 N St. Clair St, Suite 2320, Chicago, IL 60611; telephone: (312) ; fax: (312) ; info@abts.org by The Society of Thoracic Surgeons Ann Thorac Surg 2006;82: /06/$32.00 Published by Elsevier Inc