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Background. Hypothermic cardiopulmonary bypass with intervals of circulatory arrest is a useful adjunct during operations on the descending thoracic aorta and distal aortic arch when severe aortic disease precludes placement of clamps on the aorta. Hypothermia also has a marked protective effect on spinal cord function during periods of aortic occlusion. Methods. Fifty-one patients (age range, 22 to 79 years) with descending thoracic or thoracoabdominal aortic disease had resection and graft replacement of the diseased aortic segments using hypothermic cardiopulmonary bypass and intervals of circulatory arrest in situations where the location, extent, or severity of disease precluded placement of clamps on the proximal aorta (8 patients) or (in 43 patients) when extensive thoracic (11) or thoracoabdominal (32) aortic disease was present and the risk for development of spinal cord ischemic injury and renal failure was judged to be increased. Patent intercostal (below T-6) and upper lumbar arteries were attached to the graft whenever possible. Results. Thirty-day mortality was 9.8% (5 patients). Paraplegia occurred in 2 and paraparesis in 1 of the 46 30-day survivors (6.5%). Among the 27 operative survivors with thoracoabdominal aneurysms, paraplegia occurred in 1 of 12 with Crawford type I (8%), 0 of 10 with type II, and 1 of 5 with type III aneurysms (20%). Paraplegia occurred in none of the 12 patients with aortic dissection and in 2 of the 15 patients with degenerative aneurysms. Renal failure requiring dialysis occurred in 1 (2.2%) of the 46 30-day survivors. Conclusions. Hypothermic circulatory arrest is a valuable adjunct for the treatment of complex aortic disease involving the aortic arch and thoracoabdominal aorta. In patients with thoracoabdominal aneurysms, its use has been associated with a low incidence of renal failure and an incidence of paraplegia/paraparesis in traditionally high-risk subsets (type I and II aneurysms, aortic dissection), which may be less than that observed with other surgical techniques.

The cause of cerebral and peripheral embolism remains undetermined in a significant number of patients. An atherosclerotic thoracic aorta has thus far been considered to be an uncommon one. To define the potential role of the ascending thoracic aorta as an embolic source, intraoperative ultrasonic aortic imaging was performed in 1200 of 1334 consecutive patients aged 50 years and older who were undergoing cardiac surgery. Patients were divided into two groups according to the results of the ultrasound study in terms of presence or absence of atherosclerotic disease. The prevalence of previous neurological events in the two groups was characterized and compared. Ascending aortic atherosclerosis was present in 231 (19.3%) of the patients studied. Patients in this category were older (P < .0001). A higher percentage of them were smokers (P < .0001) compared with patients with less severe disease. Coronary artery disease was more extensive (P = .012), and a higher percentage of these patients had a history of peripheral vascular disease (P < .0001). Univariate analysis of the subjects with (n = 158) and without (n = 1042) previous neurological events indicated that age, body mass index, atrial fibrillation, hypertension, and atherosclerosis of the ascending aorta were associated significantly with previous occurrence of a cerebrovascular accident. For the group as a whole, multiple logistic regression analysis demonstrated that hypertension (odds ratio, 1.81; P = .002), atherosclerosis of the ascending aorta (odds ratio, 1.65; P = .013), and atrial fibrillation (odds ratio, 1.54; P = .060) were significantly and independently associated with the occurrence of previous neurological events. Atherosclerosis of the ascending aorta is an independent risk factor for cerebrovascular events. An atherosclerotic ascending aorta may represent a potential source of emboli or may be a marker of generalized atherosclerosis.

Objective The authors evaluated the protective effect of hypothermic circulatory arrest for patients with bilateral carotid artery disease who underwent cardiac surgical procedures. Summary background data Severe bilateral carotid artery disease coexisting with cardiac disease that requires surgical treatment is associated with a substantial incidence of stroke after operations that require cardiopulmonary bypass. The optimal method of management of patients with these coexisting conditions is not established clearly. Because hypothermia has a protective effect on neural and myocardial tissue during cardiac operations, a protocol employing profound hypothermia and a period of circulatory arrest was evaluated in a group of patients who underwent combined carotid and cardiac surgery who were considered to be at increased risk for the development of stroke. Methods Fifty patients with bilateral carotid artery disease, including 24 patients with high-grade unilateral stenosis and contralateral occlusion and 6 patients with 80% to 99% bilateral stenosis, underwent combined carotid endarterectomy and cardiac surgery (coronary artery bypass grafting in all 50 patients and additional procedures in 8 patients). Profound systemic hypothermia (15 C) was instituted, and the carotid endarterectomy was performed during a period of circulatory arrest that averaged 30 minutes. The cardiac procedure was performed during the periods of cooling and rewarming. Results The 30-day mortality rate was 6% (3 patients). There were no early postoperative strokes or reversible ischemic neurologic deficits. There have been seven late deaths in the postoperative period, which extends to 54 months. None of these deaths were caused by stroke. There has been one late stroke, which occurred in the distribution of the unoperated carotid artery. Conclusions This technique provides adequate protection of the brain and myocardium during combined carotid and cardiac surgical procedures and appears to reduce the frequency of stroke in the high-risk subgroup of patients with bilateral carotid artery disease.

The optimal substitute for severely diseased aortic valves in children and young adults is unknown. The use of a mechanical prosthesis requires permanent treatment of the patient with anticoagulants and is associated with thromboembolic and hemorrhagic complications. Aortic-valve allografts and porcine bioprostheses, which do not necessitate anticoagulant therapy, may deteriorate and have limited durability.We therefore evaluated the use of the autologous pulmonary valve (i.e., the patient's own pulmonary valve) and the adjacent pulmonary artery as a replacement for the aortic valve and aortic sinuses in 33 patients. Five of the patients were from 8 to 16 years of age, and 28 were from 20 to 47 years of age. The pulmonary valve and the main pulmonary artery were used to replace the diseased aortic valve and the adjacent aorta. The coronary arteries were detached from the aorta and implanted into the pulmonary artery. The pulmonary valve and artery were replaced with a cryopreserved pulmonary allograft.There were no deaths during follow-up of up to 48 months (mean, 21 months). There were no episodes of infective endocarditis, and no reoperations on the aortic root were necessary. Also, there was no evidence on echocardiography of progressive dilatation of the autografts. With color-flow Doppler imaging, 22 patients were found to have only trivial regurgitation or none, 9 patients to have mild regurgitation, and no patients to have moderate or severe regurgitation across the autograft at the most recent follow-up visit. The mean peak velocity of flow across the autograft was 1.3 m per second (upper limit of normal, 1.8), indicating the absence of stenosis. One patient required reoperation for stenosis of the pulmonary allograft.Although the pulmonary-autograft procedure is more complex than simple aortic-valve replacement, it has been safely applied in selected patients, including young adults. Intermediate follow-up indicates satisfactory function of the autografts, with no dilatation or progressive valvular regurgitation. Pulmonary-root autografts may thus be the best available substitute for diseased aortic valves in children and young adults.

During a 16-year interval ending in October 1990, 168 patients underwent 172 aortic root replacements. Thirty patients (18%) had Marfan syndrome. Annuloaortic ectasia (81 patients) and aortic dissection (63 patients) were the principal indications for operation. Twenty-seven patients (16%) had previous operations on the ascending aorta or aortic valve. The hospital mortality rate was 5% and the duration of cardiopulmonary bypass was the only significant independent predictor of early death (p = 0.017). Major modifications in technique were made in 1981, when the inclusion/wrap technique employing a composite graft (used in the first 105 procedures) was abandoned in favor of an open technique (used in 51 procedures), and in 1988, when aortic allografts and pulmonary autografts were introduced for selected conditions (reoperations, dissection, endocarditis, isolated aortic valve disease) in 16 patients. The mean duration of follow-up was 81 months. Forty-six patients were followed for more than 10 years. The actuarial survival rate was 61% at 7 years and 48% at 12 years. No significant difference in survival rate was observed between the patients with annuloaortic ectasia and aortic dissection, or between the inclusion/wrap and open techniques. However the frequency of pseudoaneurysm formation at suture lines and the frequency of reoperations on the ascending aorta and aortic valve were less with the open technique. The actuarial freedom from thromboembolism for the 152 patients with prosthetic valves was 82% at 12 years. One early and one late death occurred among the 16 patients with allograft or autograft root replacement. Anticoagulant therapy was not used in these patients and no thromboembolic episodes occurred in the follow-up period (mean, 7 months). The satisfactory results observed with extended follow-up support the continued use of the composite graft technique as the preferred method of treatment for patients with annuloaortic ectasia, persistent aneurysms of the sinuses of Valsalva following previous operations, and for patients with ascending aortic dissection who require aortic valve replacement. The availability of aortic root allografts and the perfection of techniques for safe implantation of the autologous pulmonary root into the aortic position have broadened the indications for aortic root replacement.

Background Management of the enlarged, chronically dissected aorta after previous repair of acute ascending aortic dissection or after a previous cardiac operation may present a formidable technical challenge and the optimal method of management is not clearly established. Methods Twenty-one patients with chronic type A aortic dissection (mean age 57 years) underwent resection of the ascending aorta, the aortic arch, and varying segments of the descending thoracic aorta. Single-stage replacement with perfusion of the aortic arch first to minimize the duration of brain ischemia and a bilateral anterior thoracotomy (clamshell) incision were used. Fourteen patients had undergone previous repair of acute type A dissection. Seven patients had type A dissection after aortic valve replacement (3 patients) or coronary artery bypass (4 patients). Marked enlargement of the aorta distal to the left subclavian artery precluded a two-stage repair. The mean interval between the initial and reoperative procedures was 69 months (range, 5 to 249). Results There was 1 (4.8%) hospital death. Four patients required reoperation for bleeding. One patient required a right ventricular assist device that was successfully removed. Ten patients required assisted ventilation for more than 48 hours. All were successfully weaned from ventilatory support. No patient had a stroke or other adverse neurologic outcome. There has been 1 late death (mean follow-up 2 years). Conclusions The single-stage, arch-first replacement technique is a safe and effective procedure for patients who require extensive reoperations for chronic expanding type A dissection.

Hypothermic cardiopulmonary bypass with circulatory arrest is an important adjunct for operations on the distal aortic arch, the descending thoracic, and the thoracoabdominal aorta. The safety and efficacy of this technique when compared with other adjuncts (ie, simple aortic clamping, partial cardiopulmonary bypass, regional hypothermia) is not clearly established.One hundred and ninety-two patients (age range, 20 to 83 years) with descending thoracic or thoracoabdominal aortic disease had resection and graft replacement of the involved aortic segments using hypothermic cardiopulmonary bypass and intervals of circulatory arrest (mean, 38 minutes). The technique was used when the location and severity of disease precluded placement of clamps on the proximal aorta (31 patients) or (in 161 patients) when extensive thoracic (47) or thoracoabdominal (114) aortic disease was present, and the risk for development of spinal cord ischemic injury was judged to be increased. Lower intercostal and lumbar arteries were attached separately to the aortic graft in 101 of the 161 patients (63%) who had extensive aortic replacement. No other adjuncts for spinal cord protection were used.The 30-day mortality was 6.8% (13 patients). It was 40% (8 of 20) for patients having emergent operations (acute aortic dissection or rupture) and 2.9% (5 of 172) for all others (p0.001). The 90-day mortality was 12.5% (24 patients). Paraplegia occurred in 4 and paraparesis in 1 (full recovery) of the 186 operative survivors whose lower limb function could be assessed postoperatively (2.7%). Among the 109 survivors with thoracoabdominal aortic disease, early paraplegia occurred in 1 of 36 with Crawford extent I, 0 of 42 with extent II, and 2 of 31 with extent III disease. One patient (extent II) developed paraplegia on the 9th postoperative day after a hypotensive episode. None of the 47 patients with aortic dissection developed paralysis. Among the 186 operative survivors, renal dialysis was required in 4 patients (2.2%), prolonged inotropic support in 18 (10%), reoperation for bleeding in 9 (5%), mechanical ventilation (or = 48 hours) in 64 (34%), and tracheostomy in 17 (9%). Four patients (2%) sustained a stroke.Hypothermic cardiopulmonary bypass with circulatory arrest provides safe and substantial protection against paralysis and renal, cardiac, and visceral organ system failure that equals or exceeds that of other currently used techniques but without the need of other adjuncts.

Objectives: Adult patients with aortic coarctation may have complications after childhood repair. Other adult patients have coarctation and aneurysms of the aorta and the left subclavian artery. The optimal management of such cases is not clearly established. We evaluated the role of hypothermic cardiopulmonary bypass and circulatory arrest. Methods: Thirteen adult patients (mean age 38 years) with coarctation and coexisting abnormalities of the aorta and left subclavian artery were treated. Five patients had pseudoaneurysms develop after bypass grafting (n = 3) or patch angioplasty (n = 2). These were detected a mean of 21 years (range 13-44 years) after the initial operation. Four pseudoaneurysms were asymptomatic, and 1 had ruptured. One patient had recurrent coarctation from fibrous obliteration of a 10-mm bypass graft inserted 15 years previously. The remaining 7 patients had aneurysms of the left subclavian artery (n = 5), aneurysms of the ascending aorta and arch (n = 1), or stenosis of the left subclavian artery (n = 1) in combination with moderate or severe coarctation. Resection and interposition graft replacement of the aneurysmal or stenotic aortic segments were performed in all cases with an interval of hypothermic circulatory arrest that averaged 44 ± 5 minutes (range 33-54 minutes). Seven patients had interposition graft replacement of aneurysmal or stenotic left subclavian arteries. Results: There were no in-hospital or late deaths (maximal follow-up 7 years). No patient had brain injury, paralysis, myocardial, respiratory, or renal failure. No patient has evidence of recurrent coarctation or aneurysm formation. Conclusions: Cardiopulmonary bypass with hypothermic circulatory arrest can safely be used in the treatment of complex adult coarctation. It permits accurate delineation of the anatomy with minimal dissection, avoidance of aortic clamping and sacrifice of intercostal arteries, precise interposition graft repair, and adequate protection of vital organs. J Thorac Cardiovasc Surg 2002;124:155-61

Background . The risk of aortic valve replacement (AVR) after previous coronary artery bypass grafting (CABG) is controversial. Its magnitude influences the threshold for recommending this procedure and has been cited in arguments regarding the optimal management of mild aortic stenosis at primary CABG. We therefore reviewed our experience with reoperative AVR ± CABG and the primary combined procedure. Methods . Between January 1, 1985, and June 30, 1996, 427 patients underwent primary AVR + CABG, and 52 underwent AVR ± CABG after prior CABG. Demographics, operative characteristics, and operative results were compared between groups. Data for all patients were pooled and analyzed collectively for risk factors influencing mortality. Results . The extent of native coronary artery disease and the incidence of prior myocardial infarction and stroke were greater in the reoperative group. Aortic cross-clamp and cardiopulmonary bypass times were slightly shorter, and fewer distal anastomoses were performed in the reoperative group. Operative mortality (primary group, 6.3% versus reoperative group, 7.4%) and morbidity were similar. Stepwise multivariate logistic regression analysis identified age, perioperative myocardial infarction, intraaortic balloon support, ventricular arrhythmia, perioperative stroke, and development of renal failure or acute respiratory distress syndrome, but not reoperative status, as predictors of mortality. Conclusions . The risk of AVR after previous CABG is similar to that for primary AVR + CABG. Valve replacement should, therefore, be pursued despite prior CABG when hemodynamically significant aortic stenosis develops. Furthermore, a circumspect approach to "prophylactic" AVR for mild aortic stenosis at primary CABG seems warranted.

OBJECTIVESThis study was undertaken to determine whether atherosclerosis of the ascending aorta is a predictor of long-term neurologic events and mortality.BACKGROUNDAtherosclerosis of the thoracic aorta has been recently considered a significant predictor of neurologic events and peripheral embolism, but not of long-term mortality.METHODSLong-term follow-up (a total of 5,859 person-years) was conducted of 1,957 consecutive patients ≥50 years old who underwent cardiac surgery. Atherosclerosis of the ascending aorta was assessed intraoperatively (epiaortic ultrasound) and patients were divided into four groups according to severity (normal, mild, moderate or severe). Carotid artery disease was evaluated (carotid ultrasound) in 1,467 (75%) patients. Cox proportional-hazards regression analysis was performed to assess the independent effect of predictors on neurologic events and mortality.RESULTSA total of 491 events occurred in 472 patients (neurologic events 92, all-cause mortality 399). Independent predictors of long-term neurologic events were: hypertension (p = 0.009), ascending aorta atherosclerosis (p = 0.011) and diabetes mellitus (p = 0.015). The independent predictors of mortality were advanced age (p < 0.0001), left ventricular dysfunction (p < 0.0001), ascending aorta atherosclerosis (p < 0.0001), hypertension (p = 0.0001) and diabetes mellitus (p = 0.0002). There was >1.5-fold increase in the incidence of both neurologic events and mortality as the severity of atherosclerosis increased from normal-mild to moderate, and a greater than threefold increase in the incidence of both as the severity of atherosclerosis increased from normal-mild to severe.CONCLUSIONSAtherosclerosis of the ascending aorta is an independent predictor of long-term neurologic events and mortality. These results provide additional evidence that in addition to being a direct cause of cerebral atheroembolism, an atherosclerotic ascending aorta may be a marker of generalized atherosclerosis and thus of increased morbidity and mortality.