Evaluation of spinal cord ischemia in endovascular stent graft repair and surgical operation of descending thoracic or thoracoabdominal aortic aneurysms

Between October 1996 and June 2003, endovascular stent graft repair was performed in 87 patients with descending thoracic aortic aneurysms, graft replacement was performed in 24 patients with thoracoabdominal aortic aneurysms, and endovascular stent graft repair with concomitant surgical bypass of abdominal visceral arteries was performed in 3 patients with thoracoabdominal aortic aneurysms. The retrievable stent graft was inserted and evoked spinal cord potential were monitored in order to predict spinal cord ischemia for stent graft repair. There was no paraplegia or hospital death, although 3 patients had paraparesis in stent graft repair. Two of the 3 patients with paraparesis made a full neurologic recovery. There were no cases of paraplegia or paraparesis in surgical operations with thoracoabdominal aortic aneurysm. The concomitant surgical procedure was a good technique for patients in whom cardiopulmonary bypass could not be used. Our results of stent graft repair and surgical operation for descending thoracic or thoracoabdominal aortic aneurysms were acceptable. The retrievable stent graft was useful for prediction of spinal cord ischemia before endovascular stent graft repair of descending thoracic or thoracoabdominal aortic aneurysm.     

Role of the BioMedicus Pump and Distal Aortic Perfusion in Thoracoabdominal Aortic Aneurysm Repair

Abstract: We reviewed the role of the BioMedicus pump in the reduction of neurologic complications following the repair of Type 1 and Type 2 thoracoabdominal aortic aneurysms. Since 1991, we have used several different methods for the repair of thoracoabdominal aortic aneurysms including simple cross-clamping, selective use of the BioMedicus pump, cardiopulmonary bypass with or without profound hypothermia, and most recently, distal aortic perfusion using the BioMedicus pump combined with cerebral spinal fluid drainage. This latter method has been the most promising in rectifying the side effects of aortic clamping and in providing the time necessary for thorough thoracoabdominal aortic aneurysm repair. On our service, the ongoing study of the BioMedicus pump and distal aortic perfusion in conjunction with cerebral spinal fluid drainage has shown that these adjuncts can extend the tolerance of the spinal cord to ischemia and lower the overall rate of neurologic complications for Type 1 and Type 2 thoracoabdominal aortic aneurysm repairs to a rate of 5% (early results) and 3% (late results). We highly recommend distal aortic perfusion using the BioMedicus pump combined with cerebral spinal fluid drainage for thoracoabdominal aortic aneurysm repair.     

Left heart bypass using a centrifugal pump as an adjunct measure for surgery of thoracic descending aorta]

We have employed left heart bypass (LHB) using a centrifugal pump with heparin coated tubes as an adjunct measure for surgery of thoracic descending aortic aneurysm in 8 cases. During aortic cross-clamping, LHB was controlled to maintain the distal pressure above 50 mmHg. In 7 cases, hemodynamics were stable and no complication occurred in relation with this method. However, acute heart failure due to coronary insufficiency occurred in one patient, and subsequent cardiopulmonary bypass was required to maintain systemic circulation. LHB provides adequate distal perfusion and proximal decompression in most cases, and it has also contributed to diminution of intraoperative bleeding. However, LHB can not maintain distal perfusion when acute heart failure occurs, which indicates that we have to select another adjunct measures, such as femorofemoral bypass to avoid distal hypoperfusion in cases with heart diseases.     

Progress in the treatment of aneurysms of the distal aortic arch: approach through median sternotomy

AIM: A review of past and current operative procedures for the treatment of aneurysms of the distal aortic arch is presented in conjunction with a series of 43 patients. In this study, distal aortic arch aneurysm refers to an aneurysm involving at least the origin of the left subclavian artery, but not extending beyond the left common carotid artery. We excluded dissection aneurysm and extended aneurysm to the descending thoracic aorta from this study. METHODS: Between January, 1985, and March, 2000, 43 consecutive patients (37 males, 6 females; mean age 67.5 years) underwent repair of aneurysms of the distal aortic arch. The approach to the aneurysm was through a left thoracotomy in 4 patients and a median sternotomy in 39 patients, including an additional left thoracotomy continued to a median sternotomy in 2 patients. The supportive methods during surgery were left heart bypass using a centrifugal pump in 4 patients (LHB group), cardiopulmonary bypass with selective cerebral perfusion in 11 patients (SCP group), and cardiopulmonary bypass with continuous retrograde cerebral perfusion in 28 patients (RCP group). In the RCP group, the "aortic no-touch technique" was applied in 21 patients. The operative methods were patch closure in 4 patients, graft replacement of the distal arch using the inclusion technique in 14 patients, and total arch replacement using the exclusion technique in 25 patients. RESULTS: There were 5 hospital deaths: 1 patient in the LHB group, intractable bleeding; 1 patient in the SCP group, rupture of the distal anastomosis; 3 patients in the RCP group, stroke, rupture of the dissection arising from the distal anastomosis, and perioperative myocardial infarction. Stroke occurred in 1 patient (25%) with LHB, 3 patients (27.2%) with SCP, and 1 patient (3.6%) with RCP. Among the postoperative survivors, a new onset of left recurrent nerve palsy occurred in 2 patients (66.7%) with LHB, 1 patient (10%) with SCP, and in 1 patient (4%) with RCP. No neurological injury or left recurrent nerve palsy occurred in the patients who underwent the "aortic no-touch technique". CONCLUSION: Total arch replacement with the graft exclusion technique under profound hypothermic circulatory arrest using RCP through the median sternotomy is a promising surgical treatment for atherosclerotic distal aortic arch aneurysm. The "aortic no-touch technique" further improved the surgical results of the distal aortic arch aneurysm.     

Total circulatory arrest for the replacement of the descending and thoracoabdominal aorta

HYPOTHESIS: Hypothermic total circulatory arrest (TCA) in the resection and replacement of the thoracoabdominal and descending thoracic aorta is safe, will significantly decrease the incidence of postoperative renal failure, and should be preferentially performed over left heart bypass (LHB). DESIGN: Retrospective review case series. SETTING: Large, private, urban teaching hospital. PATIENTS: All adult patients with aortic disease that involved the distal aortic arch, the descending thoracic aorta, or the thoracoabdominal aorta who underwent resection and graft replacement of the diseased segment via LHB or TCA at our institution from 1989 to 2001 are included in this study. A total of 59 patients were evaluated: 10 had descending thoracic aneurysms, 20 had thoracoabdominal aneurysms, 22 had chronic type B dissections, 4 had acute type B dissections, and 3 had adult coarctations. INTERVENTIONS: In 1989 to 1994, LHB was primarily used; in 1994 to 2001, TCA was primarily used. MAIN OUTCOME MEASURES: Renal failure, 30-day operative mortality, paraplegia, and any other morbidities. RESULTS: A significant decrease occurred in the incidence of postoperative renal failure from 15% (3/20) in patients who underwent LHB to 0% (0/39) in patients who underwent TCA (P = .04). Furthermore, a significant decrease occurred in the 30-day operative mortality, which decreased from 20% (4/20) in patients who underwent LHB to 5% (2/39) in patients who underwent TCA (P = .04). Postoperative paraplegia decreased from 5% (1/20) in patients who underwent LHB to 2.6% (1/39) in patients who underwent TCA (P > .99). CONCLUSIONS: Our use of TCA in the resection and replacement of the diseased thoracoabdominal and descending thoracic aorta has produced excellent results. Our patients have experienced no postoperative renal failure and a low 30-day operative mortality. The use of TCA in this patient population is a viable option for surgeons comfortable with the technique.     

Multiple aneurysm repair: hybrid approach to chronic dissection around visceral branches

The present case report details our experience with the hybrid approach for multiple aneurysms in the aortic arch, thoracoabdominal aorta, and around the aortic bifurcation. Total arch replacement for the arch aneurysm under hypothermic cardiopulmonary bypass with antegrade cerebral perfusion was the first stage of aneurysm repair. Five months later, bifurcated graft replacement with debranching of four abdominal branches was undertaken as the second stage of treatment. Finally, stent-graft repair for chronic dissection of the thoracoabdominal aorta was performed utilizing a Gore-Tex Tag endovascular prosthesis. Over 7 months of treatment, all aneurysms were excluded from the aortic blood flow and pressure without abdominal organ dysfunction except a transiently elevated total bilirubin level. Although the patient had an episode of minor gastrointestinal bleeding after discharge, he is currently leading a normal life without limitations at home 5 months after the stent-graft repair.     

Left heart bypass during descending thoracic aortic aneurysm repair does not reduce the incidence of paraplegia

BACKGROUND: The preferred technique for spinal cord protection during surgical repair of descending thoracic aortic aneurysms (DTAAs) remains controversial. The purpose of this retrospective analysis was to determine if the use of left heart bypass (LHB) reduced the incidence of paraplegia in patients who underwent DTAA repair. METHODS: Over a 15-year period 387 consecutive patients underwent surgical repair of DTAAs using either the "clamp-and-sew" technique (341 patients, 88.1%) or distal aortic perfusion via a LHB circuit (46 patients, 11.9%). Data regarding patient characteristics, operative variables, and outcomes were retrieved from a prospectively maintained database. The impact of LHB on the frequency of paraplegia was determined using univariate and propensity score analyses. RESULTS: There were 17 operative deaths (4.4%) including 11 patients (2.8%) who died within 30 days. Paraplegia occurred in 10 patients (2.6%). On univariate analysis increasing age (p = 0.03), increasing aortic clamp time (p < 0.001), increasing red blood cell transfusion requirements (p = 0.01), and acute dissection (p = 0.03) were associated with increased incidence of paraplegia. Patients who received LHB had a similar incidence of paraplegia (2/46, 4%) compared with those treated without LHB (8/341, 2.3%; p = 0.3). Both matching and stratification propensity score analyses confirmed that LHB was not associated with reduced risk of paraplegia. CONCLUSIONS: On retrospective analysis the use of LHB during DTAA repair did not reduce the incidence of spinal cord injury. The "clamp-and-sew" technique remains an appropriate approach to DTAA repair.     

Combined grafting of thoracic aortic aneurysm and cardiac repair using continuous cold-blood coronary perfusion.

OBJECTIVE: For patients diagnosed with combined thoracic aortic aneurysms and cardiac lesions, we conduct a 1-stage operation for ascending and aortic arch grafting. We studied surgical outcome comparatively with patients undergoing aortic grafting alone. For descending and thoracoabdominal aortic grafting, we choose a 2-stage operation. SUBJECTS AND METHODS: Subjects were 80 patients undergoing ascending and aortic arch aneurysm repair between June 1994 and March 1999. Group 1 consisted of 30 undergoing simultaneous cardiac repair. Concomitant cardiac procedures involved 21 valvular, 5 coronary arterial, and 4 valvular and coronary arterial surgeries. Group 2 consisted of 50 undergoing aortic grafting alone. We used crystalloid cardioplegia and additional antegrade continuous cold-blood coronary perfusion in Group 1, and crystalloid cardioplegia alone in Group 2. RESULTS: Hospital mortality was 10% in Group 1 and 2% in Group 2. Surgery length, cardiopulmonary bypass time, and aortic cross-clamping time in Group 1 were significantly longer than Group 2. Myocardial ischemic time did not differ significantly. Postoperative ICU stay, mechanical ventilation time and catecholamine support time did not differ significantly. Actuarial survival was 66.9 +/- 13.1% at 52 months in Group 1 and 87.2 +/- 4.8% at 57 months in Group 2 (p = 0.2918). CONCLUSION: Simultaneous cardiac repair and ascending and aortic arch aneurysm repair were conducted using continuous cold-blood coronary perfusion. Hospital mortality and mid-term survival did not differ significantly between groups.     

Cardiopulmonary bypass in surgery for interrupted aortic arch

Interrupted aortic arch is a complicated congenital heart defect. Because of its anatomic features, the conventional cardiopulmonary bypass (CPB) procedure is not suitable for the surgery of this type of lesion. Thus, we conducted a retrospective study of CPB in surgery for the disease. Ten patients with interrupted aortic arch underwent surgery by one of three different CPB methods, including profound hypothermia with circulatory arrest in four cases, profound hypothermia with low flow rate in five cases, and normothermia in one case. In profound hypothermic CPB, both ascending aorta and main pulmonary artery were cannulated. Through these two cannulas, the flow was pumped to the upper and lower body separately to cool down the body temperature. After cooling, the main pulmonary artery cannula was removed and interrupted aortic arch was corrected either under low flow rate perfusion or under circulatory arrest. After this, the other intracardiac lesions were repaired under conventional CPB. At the end of CPB, one patient demonstrated third-degree atria-ventricular block and required reinstituting CPB and a second procedure to repair the ventricular septal defect (VSD). In the intensive care unit, one patient developed lung infection and dyspnea after extubation that required intubation and mechanical ventilation for another several days. Another patient required 3 days of peritoneal dialysis caused by low cardiac output, hyperkalemia, and oliguria. All patients survived. The mechanical ventilation times were from 8 hours to 8 days and stays in the intensive care unit were from 4 to 12 days. Profound hypothermic cardiopulmonary bypass either with low flow rate or with circulatory arrest is equally the preferable choice for the surgery of interrupted aortic arch.     

Transverse aortic arch aneurysm: improved results of treatment employing new modifications of aortic reconstruction and hypothermic cerebral circulatory arrest.

The results of graft replacement for aneurysms involving the entire transverse aortic arch have lagged far behind that achieved for similar lesions located elsewhere. For example, prior to the study reported here, the mortality rate of the former, in our experience, was 25%, whereas it was only 8% for the most extensive forms of thoracoabdominal aortic aneurysms. The difference had been due to limitations and complications of methods employed for cerebral and myocardial protection. The high mortality rate in our patients was due to the deficiencies of temporary bypass graft and cardiopulmonary bypass, and separate brachiocephalic perfusion employed for this purpose. This report is concerned with the use of profound hypothermia for cerebral protection and the application of graft inclusion and direct brachiocephalic arterial reattachment to prevent bleeding in region of operation, as so successfully employed in patients with thoracoabdominal aortic aneurysms. The entire thoracic aorta was involved in four patients, the aortic valve in two patients, coronary artery bypass was performed in two patients, and the pulmonary artery was obstructed in one patient. Employing the techniques described in this report, all eight patients with these extensive lesions survived without complication.     

Renal perfusion during thoracoabdominal aortic operations: cold crystalloid is superior to normothermic blood

BACKGROUND: Renal failure remains a common complication of thoracoabdominal aortic aneurysm repair. The purpose of this randomized clinical trial was to compare two methods of selective renal perfusion--cold crystalloid perfusion versus normothermic blood perfusion--and determine which technique provides the best kidney protection during thoracoabdominal aortic aneurysm repair. METHODS: Thirty randomized patients undergoing Crawford extent II thoracoabdominal aortic aneurysm repair with left heart bypass had renal artery perfusion with either 4 degrees C Ringer's lactate solution (14 patients) or normothermic blood from the bypass circuit (16 patients). Acute renal dysfunction was defined as an elevation in serum creatinine level exceeding 50% of baseline within 10 postoperative days. RESULTS: One death occurred in each group. One patient in the blood perfusion group experienced renal failure requiring hemodialysis. Ten patients (63%) in the blood perfusion group and 3 patients (21%) in the cold crystalloid perfusion group experienced acute renal dysfunction (p = 0.03). Multivariable analysis confirmed that the use of cold crystalloid perfusion was independently protective against acute renal dysfunction (p = 0.02; odds ratio, 0.133). CONCLUSIONS: When using left heart bypass during repair of extensive thoracoabdominal aortic aneurysms, selective cold crystalloid perfusion offers superior renal protection when compared with conventional normothermic blood perfusion.     

Combined grafting of thoracic aortic aneurysm and cardiac repair using continuous cold-blood coronary perfusion

Objective: For patients diagnosed with combined thoracic aortic aneurysms and cardiac lesions, we conduct a 1-stage operation for ascending and aortic arch grafting. We studied surgical outcome comparatively with patients undergoing aortic grafting alone. For descending and thoracoabdominal aortic grafting, we choose a 2-stage operation.Subjects and Methods: Subjects were 80 patients undergoing ascending and aortic arch aneurysm repair between June 1994 and March 1999. Group 1 consisted of 30 undergoing simultaneous cardiac repair. Concomitant cardiac procedures involved 21 valvular, 5 coronary arterial, and 4 valvular and coronary arterial surgeries. Group 2 consisted of 50 undergoimg aortic grafting alone. We used crystalloid cardioplegia and additional antegrade continuous cold-blood coronary perfusion in Group 1, and crystalloid cardioplegia alone in Group 2.Results: Hospital mortality was 10% in Group 1 and 2% in Group 2. Surgery length, cardiopulmonary bypass time, and aortic cross-clamping time in Group 1 were significantly longer than Group 2. Myocardial ischemic time did not differ significantly. Postoperative ICU stay, mechanical ventilation time and catecholamine support time did not differ significantly. Actuarial survival was 66.9±13.1% at 52 months in Group 1 and 87.2±4.8% at 57 months in Group 2 (p=0.2918).Conclusion: Simultaneous cardiac repair and ascending and aortic arch aneurysm repair were conducted using continuous cold-blood coronary perfusion. Hospital mortality and mid-term survival did not differ significantly between groups.     

Surgical repair of thoracoabdominal aortic aneurysms

Morbidity and mortality following thoracoabdominal aortic aneurysm (TAAA) repair are tremendous. Preoperative assessment is essential in detecting cardiac and pulmonary risk factors in order to reduce cardiopulmonary complications. Paraplegia and renal failure are main determinants of postoperative mortality and therefore gained substantial attention during the last decades. Left heart bypass, cerebrospinal fluid (CSF) drainage and epidural cooling have significantly reduced paraplegia rate, however, this dreadful event still occurs in up to 25% of patients undergoing type II repair. Renal failure has been partly prevented by means of retrograde aortic perfusion and cooling but renal failure still remains a significant problem. We have evaluated the effects of protective measures aiming for reduction of paraplegia and renal failure. Monitoring motor evoked potentials (MEPs) is an accurate technique to assess spinal cord integrity during TAAA repair, guiding surgical strategies to prevent paraplegia. Selective volume- and pressure controlled perfusion is a technique to continuously perfuse the kidneys during aortic cross clamping and subsequent circulatory exclusion In patients with atherosclerotic thoracoabdominal aortic aneurysms, blood supply to the spinal cord depends on a highly variable collateral system. In our experience, monitoring MEPs allowed detection of cord ischemia, guiding aggressive surgical strategies to restore spinal cord blood supply and reduce neurologic deficit: overall paraplegia rate was less than 3%. We believe that these protective measures should be included in the surgical protocol of TAAA repair, especially in type II cases. Renal and visceral ischemia can be reduced significantly by continuous perfusion during aortic cross clamping in TAAA repair. Not only sufficient volume flow but also adequate arterial pressure appears to be essential in maintaining renal function.Obviously, endovascular modalities have been successfully applied in TAAA patients, the majority of which as part of hybrid procedures. Technological innovation will eventually cause a shift from open to minimal invasive surgical repair. At present, however, open surgery is considered the gold standard for TAAA repair, especially in (relatively) young patients and patients suffering from Marfan's disease.     

Hypothermic circulatory arrest and hypothermic perfusion for extensive disease of the thoracic and thoracoabdominal aorta.

BACKGROUND: Hypothermic cardiopulmonary bypass with or without an interval of circulatory arrest has been evaluated for the treatment of complex aortic disease of the descending thoracic and thoracoabdominal aorta. Hypothermia has a protective effect on spinal cord function, and its use should reduce the incidence of paraplegia and paraparesis in traditionally high-risk patients. Experimentally, the protective effect of hypothermia has been related to amelioration of excitotoxic injury by reduction of neurotransmitter release and to inhibition of delayed apoptopic cell death. METHODS: During a 12-year period, 114 patients with descending thoracic or thoracoabdominal aortic disease underwent replacement of the involved aortic segments using hypothermic cardiopulmonary bypass and intervals of circulatory arrest. The mean age of the patients was 60 years (range 22 to 79 years). Acute or chronic dissection was present in 40 patients (35%). Sixty-four patients (56%) had Crawford Types I, II, or III thoracoabdominal aneurysms. RESULTS: The hospital mortality was 8% (9 patients). Paraplegia occured in 2 and paraparesis in 1 of the 108 patients whose lower limb function was assessed postoperatively (2.8%). None of 40 patients with aortic dissection and none of the last 81 patients in the series developed paralysis. One patient developed renal failure that required dialysis. CONCLUSIONS: Our experience with hypothermic cardiopulmonary bypass and circulatory arrest confirms that hypothermia provides substantial protection against spinal cord ischemic injury. It allows complex operations on the descending thoracic and thoracoabdominal aorta to be performed with acceptable mortality, a low incidence of renal failure, and an incidence of other complications that does not exceed that reported with other techniques.     

Use of minimized extracorporeal circulation system in noncoronary and valve cardiac surgical procedures-a case series

The aim of this report is to explore application of minimized cardiopulmonary bypass (CPB) circuits in areas of cardiac surgery other than coronary bypass grafting and aortic valve surgery. We report three cases operated under minimal extracorporeal circulation support. Replacement of the descending thoracic aorta was performed in two patients; one with a descending aortic aneurysm and one with pseudoaneurysm formation after previous coarctation repair. We have also implanted a left ventricular assist device for destination therapy. The minimized extracorporeal circulation system provides optimal circulatory support, while it is associated with reduced postoperative morbidity, minimizing the side effects from the use of CPB. Moreover, when off-pump technique is attempted, it can be used as a standby circuit connected to the patient so as to enhance safety of the procedure. Minimized extracorporeal circulation systems can be used with safety and efficacy in a wide range of cardiac surgeries including descending aorta pathology and assist device implantation.     

Transapical aortic cannulation via left lateral thoracotomy for descending thoracic and thoracoabdominal aortic surgery

Two patients underwent surgery for a chronic type B dissection using a total cardiopulmonary bypass (CPB) with transapical arterial cannulation. At surgery, a total CPB was established by cannulating the left femoral artery and the ascending aorta via the ventricular apex. The patients were cooled to 30°C. The proximal anastomosis was done after cross-clamping the aortic arch between the left carotid artery and the left subclavian artery in both cases. In the first case, the entire descending thoracic aorta was replaced, and two pairs of intercostal arteries were reconstructed. The other patient underwent replacement of the proximal descending thoracic aorta. Neither patient experienced any complications. Transapical aortic cannulation is a useful option during descending thoracic and thoracoabdominal aortic surgery. It can provide more stable circulation during the cross-clamping, more gentle manipulation of the aorta by nonpulsatile flow, and more liberty in temperature control.     

Nonpenetrating trauma to the thoracic aorta

Twenty-seven patients underwent surgical repair for nonpenetrating injuries of the thoracic aorta. Emergency operation was performed in 19 patients with acute aortic injury and there were 12 survivors. Left heart bypass (LHB), external shunts, and simple aortic cross-clamping were methods employed during repair. All operative deaths occurred in the left heart bypass group. Morbidity, hospital stay, operative time, and blood loss all were markedly less in patients repaired with an external shunt or simple cross-clamping. Systemic heparinization related adversely to mortality and morbidity. Eight patients had repair of chronic post-traumatic descending aortic aneurysms. One of these had previous repair elsewhere with paraplegia and subsequent mycotic aneurysm at the graft repair site. He presented to us with massive hemoptysis. Surgical correction in the chronic group was performed using either left heart bypass, external shunt, or simple aortic cross-clamp with graft interposition. The only death occurred in a patient repaired on left heart bypass.     

Minimally Invasive Cardiac Surgery: Current Status and Perspective

Recently, the minimally invasive approach has become a growing aspect in the field of cardiac surgery with the goal of eliminating cardiopulmonary bypass (CPB) and/or median sternotomy. In coronary bypass surgery, the application of this approach is direct anastomosis, primarily of the left internal thoracic artery to the left descending coronary artery under a beating condition without the use of CPB through a small left thoracotomy minimally invasive direct coronary artery bypass (MIDCAB). In the repair of intracardiac lesions, CPB cannot be excluded, but a small right parasternal incision or small partial sternotomy (ministernotomy) has been applied for congenital defects and mitral and aortic valve lesions. With technological advances in CPB, these approaches may become more popular in the near future.     

Hypothermic circulatory arrest and hypothermic perfusion for extensive disease of the thoracic and thoracoabdominal aorta

Background: Hypothermic cardiopulmonary bypass with or without an interval of circulatory arrest has been evaluated for the treatment of complex aortic disease of the descending thoracic and thoracoabdominal aorta. Hypothermia has a protective effect on spinal cord function, and its use should reduce the incidence of paraplegia and paraparesis in traditionally high-risk patients. Experimentally, the protective effect of hypothermia has been related to amelioration of excitotoxic injury by reduction of neurotransmitter release and to inhibition of delayed apoptopic cell death.Methods: During a 12-year period, 114 patients with descending thoracic or thoracoabdominal aortic disease underwent replacement of the involved aortic segments using hypothermic cardiopulmonary bypass and intervals of circulatory arrest. The mean age of the patients was 60 years (range 22 to 79 years). Acute or chronic dissection was present in 40 patients (35%). Sixty-four patients (56%) had Crawford Types I, II, or III thoracoabdominal aneurysms.Results: The hospital mortality was 8% (9 patients). Paraplegia occured in 2 and paraparesis in 1 of the 108 patients whose lower limb function was assessed postoperatively (2.8%). None of 40 patients with aortic dissection and none of the last 81 patients in the series developed paralysis. One patient developed renal failure that required dialysis.Conclusions: Our experience with hypothermic cardiopulmonary bypass and circulatory arrest confirms that hypothermia provides substantial protection against spinal cord ischemic injury. It allows complex operations on the descending thoracic and thoracoabdominal aorta to be performed with acceptable mortality, a low incidence of renal failure, and an incidence of other complications that does not exceed that reported with other techniques.