Considerations for prostheses choice in multiple valve surgery.

OBJECTIVES: The prosthesis type for multiple valve surgery (replacement of two or more diseased native or prosthetic valves, replacement of two diseased valves with repair/reconstruction of a third, or replacement of a single diseased valve with repair/reconstruction of a second valve) remains inadequately evaluated. The clinical performance of multiple valve surgery with bioprostheses (BP) and mechanical prostheses (MP) was assessed to compare patient survival and composites of valve-related complications. METHODS: Between 1975 and 2000, 1245 patients had multiple valve surgery (BP 785, mean age 62.0 ± 14.7 years; and MP 460, mean age 56.9 ± 12.9 years). There were 1712 procedures performed [BP 969(56.6%) and MP 743(43.4%). Concomitant coronary artery bypass (conCABG) was BP 206(21.3%) and MP 105(14.1%) (p = 0.0002). The cumulative follow-up was BP 5131 years and MP 3364 years. Independent predictors were determined for mortality, valve-related complications and composites of complications. RESULTS: Unadjusted patient survival at 12 years was BP 52.1 ± 2.1% and MP 54.8 ± 4.6% (p = 0.1127), while the age adjusted survival was BP 48.7 ± 2.3% and MP 54.4 ± 5.0%. The predictors of overall mortality were age [Hazard Ratio (HR) 1.051, p < 0.0001], previous valve (HR 1.366, p = 0.028) and conCABG (HR 1.27, p = 0.021). The actual freedom from valve-related mortality at 12 years was BP 85.6 ± 1.6% and MP 91.0 ± 1.6% (actuarial p = 0.0167). The predictors of valve-related mortality were valve type (BP > MP) (2.61, p = 0.001), age (HR 1.032, p = 0.0005) and previous valve (HR 12.61, p < 0.0001). The actual freedom from valve-related reoperation at 12 years was BP 60.8 ± 1.9% and MP85.6 ± 2.1% (actuarial p < 0.001). The predictors of valve-related reoperation were valve type (MP > BP) (HR 0.32, p < 0.0001), age (HR 0.99, p = 0.0001) and previous valve (HR 1.38, p = 0.008) CONCLUSIONS: Overall survival (age adjusted) is differentiated by valve type over 10 and 12 years and valve-related mortality and valve-related reoperation favours the use of mechanical prostheses, overall for multiple valve surgery.

Pulse wave velocity involving proximal portions of the aorta correlates with the degree of aortic dilatation at the sinuses of valsalva in ascending thoracic aortic aneurysms.

OBJECTIVE: To determine the relationship between arterial stiffness measured in different aortic segments and the presence and extent of ascending thoracic aortic aneurysm (ATAA). METHODS: Patients at a Thoracic Aortic Diseases clinic at a University teaching hospital were compared to patients attending a Cardiology outpatient Clinic at the same institution. A non-invasive measure of vascular stiffness was performed using pulse wave velocity (PWV) measurement of several vascular segments-carotid-femoral pulse wave velocity (cfPWV), heart-femoral pulse wave velocity (hfPWV) and brachial-ankle pulse wave velocity (baPWV). Aortic dimensions were measured on echocardiogram. RESULTS: Patients with ATAA (N = 32) were 66 years and the same age as those without ATAA (N = 46). There was no significant difference between those with or without aortic aneurysm with respect to cfPWV, hfPWV or baPWV. In ATAA, there was a significant (p <0.05) inverse correlation between aortic diameter at the sinuses of Valsalva and cfPWV, as well as hfPWV, but not with baPWV. This relationship was not evident in persons without ATAA. CONCLUSION: Reduced aortic stiffness (increased compliance), assessed by cfPWV or hfPWV, correlates with larger aortic size of ATAA at the level of the sinuses of Valsalva but not at the ascending aorta, suggesting cfPWV may be a useful method to assess the size of ATAA at the level of the sinuses of Valsalva. Overall aortic stiffness assessed by PWV did not differentiate persons with or without an ATAA, in individuals who do not have a genetic or inheritable cause of their ATAA.

Long-term outcomes after thoracic aortic surgery: a population-based study.

OBJECTIVE: Long-term survival after aortic surgery has remained largely unexplored, despite suggestions of superior durability compared with endovascular techniques. The objective of the present study was to determine the long-term survival after open thoracic aortic surgery and to identify the predictors of mortality. METHODS: The provincial database was accessed to identify all adult patients who had undergone primary open thoracic aortic surgery in British Columbia since 1993. Kaplan-Meier survival analyses were performed for the entire group and by year of surgery, urgency of surgery, and aortic segment requiring surgery. Multivariate analyses were performed to identify the predictors of mortality. RESULTS: From January 1993 to June 2010, 1960 patients underwent primary open thoracic aortic surgery at 4 hospitals in British Columbia. Overall, the 30-day mortality was 9.1%, with a perioperative stroke rate of 5.8%. Long-term survival was 77.7%, 59.6%, and 44.7% at 5, 10, and 15 years, respectively. Subanalyses demonstrated improved long-term survival in the modern era; among patients undergoing elective aortic surgery; and among patients undergoing surgery on the ascending aorta or aortic root (P < .0001). The preoperative characteristics associated with decreased long-term survival included age older than 65 years, acute renal failure, dialysis, cerebrovascular accident, chronic obstructive pulmonary disease, peripheral vascular disease, and descending or thoracoabdominal aorta surgery. CONCLUSIONS: Long-term survival after elective thoracic aortic surgery is excellent, with improved outcomes in the modern era. Several preoperative risk factors associated with decreased survival were identified, which could assist in risk stratification and patient selection. Finally, the long-term survival rates identified in the present study should serve as a benchmark to which new aortic interventions should be compared.

Aortic wall stress in hypertension and ascending thoracic aortic aneurysms: implications for antihypertensive therapy.

The objective of this study was the evaluation of aortic wall stress in patients with ascending thoracic aortic aneurysms (TAA) because of the paucity of data to guide medical therapy for blood pressure (BP) management in TAA. Twelve men, age 67.4 ± 3.3 years (SEM) with hypertension and ascending TAA without other etiology, previous aortic surgery or associated significant aortic valve disease, had maximum dimensions of the ascending aorta measured from CT angiogram (CTa) and transthoracic echocardiogram (TTE) with aortic wall thickness measured on TTE. Wall stress (WS(σ)(P)) at peak systolic BP (SBP) was expressed by the equation: WS(σ)(P) = 2LCSA × SBP/MCSA, where LCSA is ascending aorta luminal cross-sectional area; MCSA is the surface area of the aortic wall cross sectional area considering aortic wall thickness. There was no significant difference in wall stress from TTE or CTa although mean wall stress was slightly larger when calculated from CTa. For each 5 mmHg increment in Systolic BP (SBP), there was a 3.9 kPa increase in wall stress that was 3.5 kPa for small aneurysms (40 to <45 mm) and 4.4 kPa for larger aneurysms (45-52 mm). There was a 33.0 ± 1.2 % reduction in wall stress when SBP went from 165 to 110 mmHg with a 21.0 ± 0.7 % reduction in wall stress found when SBP was reduced from 140 to 110 mmHg. These data, in patients with hypertension and ascending TAA suggest that meaningful reductions in aortic wall stress occur with reductions of SBP and this benefit extends to SBP levels <140 mmHg.

Vancouver simplified grading system with computed tomographic angiography for blunt aortic injury.

OBJECTIVE: Delineation of blunt aortic injury by computed tomographic angiography guides management of this potentially fatal injury. Two existing grading systems are problematic to apply and not linked to outcomes. A simplified computed tomographic angiography-based grading system, linked to clinical outcomes, was developed, and feasibility and reliability were evaluated. METHODS: Retrospective review was performed of all blunt aortic injury cases presenting to a single provincial quaternary referral center designated for blunt aortic injury management between 2001 and 2009. Management, associated injuries, hospital survival, and cause of death were determined. Initial computed tomographic angiography was reviewed, and injuries were graded according to the new Vancouver simplified grading system by 2 study authors. Three additional trauma radiologists then graded the aortic injuries with the 2 existing systems and the simplified system. Interrater reliability was determined. RESULTS: Forty-eight patients were identified. Two had minimal aortic injury (grade I), 7 had an intimal flap larger than 1 cm (grade II), 32 had traumatic pseudoaneurysm (grade III), 6 had active contrast extravasation (grade IV), and 1 could not be rated. Survivals were 100%, 90%, and 33% for grades I and II, III, and IV, respectively. Of grade III injuries, 14% were medically managed, 68% repaired endovascularly, and 18% repaired with open surgery. Interrater correlation was best with the simplified score, with only 0.5% of cases unable to be classified. CONCLUSIONS: The Vancouver simplified blunt aortic injury grading system is easy to use and correlates with clinical outcomes. Prospective external validation is required.

Prophylactic intravenous magnesium sulphate in addition to oral {beta}-blockade does not prevent atrial arrhythmias after coronary artery or valvular heart surgery: a randomized, controlled trial.

BACKGROUND: Atrial arrhythmias (AA) are an important cause of morbidity after cardiac surgery. Efforts at prevention of postoperative AA have been suboptimal. Perioperative beta-blocker administration is the standard of care at many centers. Although prophylactic administration of magnesium sulfate (MgSO(4)) has been recommended, review of all previously published trials of MgSO(4) reveals conflicting results. This study was designed to address methodological shortcomings from previous studies and is the largest randomized, placebo-controlled trial of intravenous (IV) MgSO(4) for the prevention of AA after coronary artery bypass grafting or cardiac valvular surgery. METHODS AND RESULTS: A total of 927 nonemergent cardiac surgery patients were stratified into 2 groups: isolated coronary artery bypass grafting (n=694), or valve surgery with or without coronary artery bypass grafting (n=233), and randomized to receive either 5g IV MgSO(4) or placebo on removal of the cross-clamp, followed by daily 4-hour infusions, from postoperative day 1 until postoperative day 4. All patients were treated according to an established oral beta-blocker protocol. Postoperative serum Mg levels were checked and standard of care was to administer IV MgSO(4) for low serum levels. The primary end point was AA lasting > or =30 minutes or requiring treatment for hemodynamic compromise. There were no differences in the incidence of AA between patients who received IV MgSO(4) or placebo (26.4% versus 24.3%, respectively). The results were similar when broken down according to stratified groups. CONCLUSIONS: In patients treated with a protocol for postoperative oral beta-blocker after nonemergent cardiac surgery, the addition of prophylactic IV MgSO(4) did not reduce the incidence of AA.

Seven-year results with the St Jude Medical Silzone mechanical prosthesis.

OBJECTIVE: The Artificial Valve Endocarditis Reduction Trial was stopped on January 21, 2000, due to a higher incidence of paraprosthetic leak in the St Jude Medical Silzone prosthesis compared with the conventional prosthesis. The Artificial Valve Endocarditis Reduction Trial investigators reported the 2-year results in 2002. This retrospective study assessed the influence on thromboembolism and paraprosthetic leak to 7 years. METHODS: A total of 253 patients had 254 operations: 80 aortic valve replacements, 139 mitral valve replacements, and 35 multiple replacements with placement of Silzone prostheses. The mean age was 58.6 years (range 21-84 years, median age 59.8 years), and there were 126 women (49.8%) and 74 concomitant procedures (coronary artery bypass 28.9%). RESULTS: Major paraprosthetic leak (repair, re-replacement, or mortality) occurred in 10 of the original procedures after 30 days (3 aortic valve replacements, 3 mitral valve replacements, 4 multiple replacements). Nine occurrences in 8 patients-5 early (2 years)-were managed. Seven were managed with definitive re-replacement. One was an early nonoperative fatality. There was 1 late fatality after the second late paraprosthetic leak reoperation. One of the 10 procedures occurring after 2 years had mild to moderate aortic valve replacement paraprosthetic leak managed as an incidental re-replacement at the time of correction of supra valvular patch stenosis. One additional occurrence, in addition to the 8 patients (<30 days), was considered a technical error and not related to the Silzone prosthesis and was replaced with a Silzone prosthesis. The linearized rate of paraprosthetic leak within the first 2 years of follow-up was 1.3%/patient-year and after 2 years was 0.4%/patient-year. The linearized occurrence rate for major thromboembolism was 0.42%/patient-year for aortic valve replacement and 1.71%/patient-year for mitral valve replacement. CONCLUSIONS: Paraprosthetic leak with the St Jude Medical Silzone prosthesis was managed both during the early (2years) intervals with re-replacement. Late managed events may be manifestations of earlier occurring paraprosthetic leak. Follow-up echocardiograms should meet standards of care, 6 to 12 months after surgery and at the slightest suspicion of dysfunction. There is no advanced continuing risk of the St Jude Medical Silzone prosthesis.

Mitral valve disease: if the mitral valve is not reparable/failed repair, is bioprosthesis suitable for replacement?

OBJECTIVE: The durability of mitral bioprostheses has long been known to be inferior to aortic bioprostheses. Mitral valve reconstruction/repair is currently recommended for most mitral valve procedures. The choice of prostheses for non-reparable or failed mitral valve repairs has not been specified or given appropriate attention within the literature. The objective of this study is to address the role of bioprostheses in the specific subset of non-reparable or failed repair patients by using the knowledge of the general durability of mitral porcine bioprostheses, inclusive of the Carpentier-Edwards mitral porcine bioprosthesis. METHODS: The CE-SAV was implanted in 1135 patients (1175 operations) for mitral valve replacement (MVR) from 1982 to 2000. The mean age was 65.0+/-12.1 years (range 13-86 years). The mean follow-up was 6.4+/-4.5 years, 7555.9 patient-years and 98.3% complete. The evaluation considered freedom from structural valve deterioration (SVD) and freedom from composites of complications, as well as risk assessment. RESULTS: For the 51-60 year age group, the actual and actuarial freedom from SVD was, at 18 years, 56.0+/-4.1% and 14.7+/-5.8%; for the 61-70 year age group was, at 18 years, 69.6+/-2.6% and 26.5+/-5.9%, respectively. For the >70 group, at 15 years was 92.2+/-2.0% and 69.0+/-9.7%, respectively. There were a total of 256 SVD events with 31 fatalities and 226 reoperations with 10 fatalities (4.42%). The predictors of SVD were age (hazard ratio [HR] 0.98, p=0.0002), concomitant CAB (HR 0.66, p=0.020) and valve size (HR 1.08, p=0.034). The overall actual freedom, at 15-18 years, for >70 age group was, for valve-related reoperation, 94.3+/-1.5%; and for valve-related mortality was 87.8+/-2.3%. CONCLUSIONS: The CE-SAV mitral porcine bioprosthesis cannot be recommended as representative of prosthesis-type of choice for non-reparable or failed repair of native mitral valves for ages 70 years of age. The clinical performance of the CE-SAV is similar to other mitral bioprostheses.

Early antithrombotic therapy for aortic valve bioprostheses: is there an indication for routine use?

BACKGROUND: Consensus reports over the past 10 years from the United States, Europe, United Kingdom, and Canada have not provided consistent guidelines for antithrombotic therapy of aortic valve bioprostheses for the three-month period after surgery. This study was conducted to determine if antithrombotic therapy was protective against TE with aortic bioprostheses 30 days or less after aortic valve replacement (AVR). METHODS: From 1994 to 2000, 1,372 patients implanted with three currently marketed aortic bioprostheses, Medtronic Mosaic (Medtronic, Inc, Minneapolis, MN) (415 patients), Carpentier-Edwards SAV (462), and Carpentier-Edwards PERIMOUNT (495) (Edwards Lifesciences, Irvine, CA), with a mean age of greater than 70 years were evaluated. Patient populations were comparable, inclusive of concomitant coronary artery bypass grafting (CABG) for the overall populations and for patients greater than 70 years. RESULTS: There were 37 thromboembolic (TE) events: major TE, 14; reversible ischemic neurologic deficit (RIND), 12; and minor TE, 11. There were 4 TE deaths. Multivariate (stepwise logistic regression) analysis revealed no predictive risk factors for overall TE. For the combination of major TE plus RIND there were two predictive risk factors with analysis of 12 risk variables: preoperative cerebrovascular accident (odds ratio [OR] 4.45, 95% confidence interval [CI] 1.17 to 16.87, p = 0.028); and concomitant CABG (OR 3.19, 95% CI 1.16 to 8.76, p = 0.025). Neither anticoagulant nor antiplatelet therapies gave significant protection. CONCLUSIONS: There does not appear to be an indication for routine antithrombotic management. The study supports the potential use of antithrombotic therapy for comorbidities of preoperative cerebrovascular accident and concomitant CABG but not atrial fibrillation, left ventricular dysfunction, or elderly age greater than 70 years. Vascular burden and advanced age are likely contributing factors to these independent predictors. There may still be a need for, or at least consideration of, a randomized trial for AVR with bioprostheses.

Aortic arch reconstruction: safety of moderate hypothermia and antegrade cerebral perfusion during systemic circulatory arrest.

BACKGROUND AND AIM: The ideal strategy for cerebral protection during aortic arch (AA) reconstructive surgery remains undefined. Antegrade cerebral perfusion (ACP) during systemic circulatory arrest (SCA) may provide superior results; however, optimal systemic temperature is undetermined. Our objective was to determine whether "deep" hypothermia is necessary during ACP with SCA, and whether the degree of hypothermia is associated with neurologic outcomes postoperatively. METHODS: Retrospective series of 72 consecutive patients (aged 65.9 +/- 3.2 years) who underwent AA reconstructive surgery at Vancouver General Hospital using a cerebral protection strategy of ACP with SCA between December 1995 and December 2002. Patients were divided into two groups according to lowest systemic temperature: <22 degrees C (n = 52) and > or =22 degrees C (n = 20). RESULTS: ACP was via right axillary or innominate artery, +/- left common carotid cannulation. Median SCA time with ACP was not different between groups. There were four hospital deaths (5.6%) (three from the <22 degrees C group). Eight patients (11.2%) had major neurologic injuries (seven from the <22 degrees C group): 4 (5.6%) permanent (1 fatal) and 4 (5.6%) temporary. There was a trend toward a significantly higher incidence of delirium in the <22 degrees C group than the > or =22 degrees C group (30.8 vs 10.0%, respectively, p = 0.07). CONCLUSIONS: In our experience, SCA with ACP was a safe technique for AA reconstructive surgery. The observation of a larger number of major neurologic injuries, and a trend toward a higher incidence of delirium in the <22 degrees C group, suggests that systemic temperatures below 22 degrees C may not be necessary and may be associated with a higher incidence of neurologic injury when using ACP during SCA.

Carpentier-Edwards supra-annular aortic porcine bioprosthesis: clinical performance over 20 years.

OBJECTIVE: Experience with the Carpentier-Edwards supra-annular porcine bioprosthesis (Edwards Lifesciences, Irvine, Calif) has been evaluated longitudinally over 20 years. Clinical performance was evaluated by actuarial and actual analysis. Hemodynamic performance was evaluated by echocardiographic/Doppler assessment. Morphology of structural failure was evaluated from pathologic examinations. METHODS: From 1981 through 1999, 1823 patients (mean age, 68.9 +/- 10.9 years; range, 19-89 years) underwent 1847 procedures. Concomitant coronary artery bypass was performed in 788 (42.7%) patients. Previous valve procedures were performed in 107 (5.8%) patients, and other cardiac procedures were performed in 87 (4.7%) patients. RESULTS: The overall valve-related complication rate was 4.36% per patient-year (630 patients), with a fatality rate of 0.96% per patient-year (139 patients). Patient survival at 18 years was 15.8% +/- 1.6%. Overall late mortality rate was 6.3% per patient-year. Overall actual cumulative freedom at 18 years from reoperation was 85.0% +/- 1.2%, valve-related mortality was 88.7% +/- 1.1%, and valve-related residual morbidity was 96.3% +/- 5.0%. Actual freedom from structural valve deterioration at 18 years was 86.4% +/- 1.2% overall, 90.5% +/- 1.8% for age 61 to 70 years, and 98.2% +/- 0.6% for age greater than 70 years. Structural valve deterioration presented with pathologic evidence consistent with stenosis in 27.6% and insufficiency in 72.4%. Hemodynamic performance at 1 year revealed normal effective orifice area indexes for sizes 23 to 27 mm and mild-to-moderate reduction for size 21 mm. CONCLUSIONS: The Carpentier-Edwards supra-annular aortic porcine bioprosthesis continues to provide excellent freedom from structural valve deterioration and overall freedom from valve-related residual morbidity, mortality, and reoperation up to 18 years. Hemodynamic performance is satisfactory. The prosthesis remains recommended for patients older than 70 years and for patients 61 to 70 years of age, especially when comorbid risk factors are not anticipated to provide extended survival.

Medtronic mosaic porcine bioprosthesis: investigational center experience to six years.

BACKGROUND AND AIM OF THE STUDY: The findings of this single-center experience with the Medtronic Mosaic porcine bioprosthesis were evaluated to determine the clinical performance of the valve. METHODS: Between 1994 and 2000, a total of 657 patients was implanted with the prosthesis. Aortic valve replacement (AVR) was performed in 415 patients (mean age 70.5+/-10.7 years; range: 26-89 years) and mitral valve replacement (MVR) in 242 patients (mean age 70.5+/-9.5 years; range: 19-86 years). Concomitant coronary artery bypass (CAB) was performed in 51.1% and 46.7% of AVR and MVR patients, respectively. The majority of patients were aged over 70 years (59.8% AVR, 58.7% MVR). RESULTS: Survival at six years was 73.0+/-2.4% after AVR, and 74.0+/-5% after MVR (p = NS). Actual freedom from valve-related mortality at six years was 98+/-1% for AVR and 96+/-1% for MVR; freedom from overall thromboembolism (TE) was 86+/-3% for AVR and 89+/-2% for MVR. After AVR, 42 thromboembolic events occurred in 39 patients (23 minor; 14 major; three reversible ischemic neurologic deficits (RIND); two thrombosis). After AVR, the late TE rate was 2.1% per pt-yr, and the major rate 0.6% per pt-yr (exclusive of thrombosis). The overall TE rate after AVR was 2.9% per pt-yr (major rate 1% per pt-yr). After MVR, 25 events occurred in 24 patients (10 minor; eight major; five RIND; two thrombosis). After MVR, the late TE rate was 2.6% per pt-yr, and the major rate 0.7% per pt-yr (exclusive of thrombosis). The overall TE rate after MVR was 3.5% per pt-yr (major rate 1.1% per pt-yr). There were four cases of structural valve deterioration (SVD) (two each after AVR and MVR). Reoperation was performed in three of four cases of thrombosis, and in two of four cases of SVD. CONCLUSION: The Medtronic Mosaic porcine bioprosthesis is safe and effective. The rate of SVD after six years was low, being zero in the aortic position of patients aged >60 years, and zero also in the mitral position of patients aged <60 years. The incidence of early and late thromboembolism was contributed to by the advanced age of the patient population.

Intraoperative spinal cord monitoring during descending thoracic and thoracoabdominal aneurysm surgery.

BACKGROUND: Postoperative paraplegia is one of the most dreaded complications after descending thoracic and thoracoabdominal aneurysm surgery. In this study, intraoperative monitoring was applied during resection of descending thoracic and thoracoabdominal aneurysms to detect spinal cord ischemia and help prevent paraplegia. METHODS: Fifty-six patients (descending thoracic, 25; thoracoabdominal, 31) were monitored intraoperatively with both motor- (MEP) and somatosensory- (SSEP) evoked potentials. MEPs were elicited with transcranial electrical stimulation and recorded from the spinal epidural space (D wave) or peripheral muscles (myogenic MEP). SSEPs were obtained with median and tibial nerve stimulation. RESULTS: A total of 16 patients (28.6%) showed MEP evidence of spinal cord ischemia, only 4 of whom had delayed congruent SSEP changes. In 13 patients (23.2%), ischemic changes in MEPs were reversed by reimplanting segmental arteries or increasing blood flow or blood pressure. None of these 13 patients suffered acute paraplegia regardless of the status of SSEP at the end of the procedure, but 1 of them developed delayed postoperative paraplegia after multisystem failure. Three patients (5.4%) who had persistent loss of MEPs despite of recovery of SSEPs awoke paraplegic. CONCLUSIONS: The results demonstrate that compared with SSEP, MEP, especially myogenic MEP, is more sensitive and specific in detection of spinal cord ischemia, and that intraoperative monitoring can indeed help prevent paraplegia.

Traumatic rupture of the thoracic aorta: third decade of experience.

BACKGROUND: Traumatic rupture of the thoracic aorta is a relatively common injury of deceleration accidents, usually high-speed motor vehicle accidents. Spinal cord injury has been a well-documented complication of surgical management. The use of nonheparinized partial bypass with a centrifugal pump was evaluated for protection against spinal cord injury and reduction of risk of associated injuries. METHODS: From 1989 to 1999, the third decade of the authors' experience, traumatic rupture was diagnosed in 58 patients (male 46 and female 12; mean age 39.9 years, range 17 to 85). Associated injuries were documented in 98.3% (57 patients). In all, 45 patients (77.6%) had the opportunity for definitive surgical management; 42 (93.3%) were managed with partial cardiopulmonary bypass, 35 without the use of heparin. Full cardiopulmonary bypass was utilized in 1 patient while 2 had repair without cardiopulmonary bypass support. Thirteen patients did not have the opportunity for definitive surgical management, 1 death on arrival, 8 (61.5%) suspected, and 4 (30.8%) diagnosed. RESULTS: There were 6 deaths in the surgical group, 5 in nonheparinized patients. The causes were intraoperative hypovolemia (2), anoxic brain death after intraoperative cardiac arrest (1), sepsis (1), and adult respiratory distress syndrome (1). The other was in the simple aortic cross-clamp group from intraoperative pulmonary compromise. There was one spinal cord injury, paraparesis in 1 of the 2 patients managed without bypass support. The total hospital stay ranged from 8 to 112 days, primarily owing to management of associated injuries. Of the 13 patients who did not have the opportunity for definitive surgical management, 5 had unsuccessful emergency thoracotomy and 3 survived the hospital course without surgery. Of the total population, the overall mortality was 27.6%, whereas the mortality of the potentially operable patients was 25.8%. Of the surgical group, the intraoperative mortality was 6.7% and 30-day mortality was 13.3%. CONCLUSIONS: Spinal cord injury was prevented by the use of partial cardiopulmonary bypass. Nonheparinized bypass was likely to be a contributory factor to lack of mortality directly related to associated injuries.