Results of immediate surgical treatment of all acute type A dissections.

BACKGROUND: Surgery for acute type A aortic dissection is associated with a high mortality rate and incidence of postoperative complications. This study was designed to explore perioperative risk factors for death in patients with acute type A aortic dissection. METHODS AND RESULTS: One hundred twenty-four consecutive patients with acute type A aortic dissection between 1984 and 1998 were reviewed. All underwent operation with resection of the intimal tear and open distal anastomosis: 107 patients had surgery within 24 hours and 17 patients had surgery within 72 hours of symptom onset. Median age was 62 years (23 to 89); 89 were men. Forty-three patients had ascending aortic replacement only, 72 had hemiarch repair, in 2 the entire arch was replaced, and in 7 replacement included the proximal descending aorta. The aortic valve was replaced in 54 patients, resuspended in 52, and untouched in 18. Hospital mortality rate was 15.3% (19 of 124): of these, 3 patients died during surgery, 4 had fatal rupture of the distal aorta before discharge, and 2 died of malperfusion-related complications. Multivariate analysis revealed age >60, hemodynamic compromise, and absence of hypertension as preoperative indicators of hospital death (P:<0.05); the presence of new neurological symptoms was a significant preoperative risk factor in univariate analysis. Ominous intraoperative factors included contained hematoma and a comparatively low esophageal temperature but not cerebral ischemic time (mean 32 minutes). The site of the intimal tear did not influence outcome, but mortality rate was higher with more extensive resection: 43% with resection including the descending aorta died versus 14% with only ascending aorta or hemiarch replacement. Overall 5- and 10-year survival was 71% and 54%, respectively; among discharged patients (median follow-up 41 months) survival was 84% and 64% versus expected US survival of 92% and 79%. CONCLUSIONS: Immediate surgical treatment of all acute type A dissections with resection of the intimal tear and use of hypothermic circulatory arrest for distal anastomosis results in acceptable early mortality rates and excellent long-term survival.

Selegiline use to prevent progression of Parkinson's disease. Experience in 22 de novo patients.

To test the hypothesis that selegiline (L-deprenyl), a selective inhibitor of B-type monoamine oxidase, can halt the natural progression of Parkinson's disease, its use in 22 naive patients (mean age, 58 years; mean Parkinson's disease duration, 2.3 years) in the early stages (1 to 2) of the disease was studied. Patients were started and maintained on a daily dose of 10 mg of selegiline, and they underwent neurologic examinations at 3-month intervals using our center's disease staging and total rated disability scores. The criterion set for disease progression was defined as either the appearance of a new objective sign and/or a definite, persistent worsening (greater than 25%) of existing signs after the initiation of the selegiline trial. Patients remained on a regimen of selegiline [corrected] for periods ranging from 7 to 84 months. At the time of their latest neurologic examination, 17 (77%) of the 22 patients had conditions that demonstrably worsened with selegiline alone at an average of 10.8 months from the start of the drug therapy. Six of these 17 patients with worsening conditions (or 27% of the original 22) eventually required the addition of levodopa with carbidopa (Sinemet) on average at 13 months from the start of selegiline therapy; they have continued, to date, taking this combination for an additional mean follow-up period of 20.7 months. Four of the original 22 patients had relatively unchanged, stable neurologic status at the time of their latest examination (average follow-up period, 11.6 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Selegiline as an adjunct to conventional levodopa therapy in Parkinson's disease. Experience with this type B monoamine oxidase inhibitor in 200 patients.

Two hundred patients at a median age of 63 years, receiving conventional levodopa therapy for 8 years, who had had Parkinson's disease for 10 years, tried a regimen of selegiline (L-deprenyl), a type B monoamine oxidase inhibitor, at a daily dose of 10 mg, for varying periods from less than 6 months to more than 24 months (28% over 24 months). Selegiline does improve parkinsonism during the initial 6 months to 12 to 24 months of combined therapy in one third to almost half of patients with an end-of-dose type of response to long-term levodopa therapy. However, even this particular class of patients is unable to maintain such an improvement by 36 months, much less by 48 months, from the start of the selegiline trial. About one quarter of poor responders to levodopa and those with random deterioration show improvement in their parkinsonian status in the first 6 months of the selegiline trial, but their conditions quickly deteriorate by 1 year. The predominant pattern of response to previous levodopa therapy and the severity of the total disability score at the initiation of the selegiline trial were the two variables that were predictive of risk of failure with the drug. No evidence suggested that selegiline decreases the excess mortality rate of Parkinson's disease above that achieved with the use of levodopa alone. Selegiline as an adjunctive agent to conventional levodopa therapy was not unduly impressive with regard to preventing progression of Parkinson's disease.

National sharing of cadaveric isolated intestinal allografts for human transplantation: a feasibility study.

UNLABELLED: Most isolated intestinal graft losses are immunological. We conducted a pilot study to evaluate the feasibility of national sharing of HLA no-mismatch allografts for cadaveric isolated intestinal transplantation. METHODS: UNOS data were analyzed in a theoretical model. Part I: All solid organ donors between 1/95-8/97 who would have met criteria for bowel donation were considered potential donors for all recipients who actually received isolated intestinal transplants during this period. We then determined how many donor intestines could have been directed to no-mismatch candidates had national sharing been in place. Donor exclusion criteria were CMV+ donors to CMV- recipients, hemodynamic instability, age >50, size mismatch (donor weight greater than recipient), and obesity. Mean and median waits for transplants, as well as theoretical mean and median waits for transplants that would have occurred given national sharing, were calculated. Part II: We estimated, based on registry graft survival data, the number of intestinal transplants necessary to demonstrate a no-mismatch graft survival advantage at 2 years. RESULTS: Part I: Although no actual cadaveric no-mismatch transplant was performed, 12-17% of patients could have received no-mismatch allografts had sharing been in place, using various donor acceptance criteria. The impact on waiting time was variable. Part II: Accepting a 15% rate of no-mismatch cases and a survival advantage of 10% at 2 years, 793 transplants would be required to prove an advantage to HLA matching at P<0.05. If the graft survival advantage were 20% at 2 years, the time to show significance would be approximately 5 years. Using early acute rejection as an endpoint could require fewer transplants (93), and only a few years to complete the study. CONCLUSIONS: National sharing of cadaveric isolated intestinal allografts is feasible. Median waits would not be significantly increased. The time necessary to prove graft survival advantage would be considerable, but a difference in the rate of acute rejection could be seen within 2 years. Additionally, a national sharing arrangement might improve the overall outcome of isolated intestinal transplantation.

Long-term medical complications in patients surviving > or = 5 years after liver transplant.

BACKGROUND: Short-term outcomes of liver transplantation are well reported. Little is known, however, about long-term results in liver recipients surviving > or =5 years. We sought to analyze long-term complications in liver recipients surviving > or =5 years after transplant, to assess their medical condition and to compare findings to the general population. METHODS: We analyzed the chart and database records of all patients (n=139) who underwent liver transplantation at a major transplant center before January 1, 1991. Outcome measures included the presence of diabetes, hypertension, heart, renal or neurological disease, osteoporosis, incidence of de novo malignancy or fracture, or other pathology, body mass index, serum cholesterol and glucose, liver function, blood pressure, frequency of laboratory and clinic follow-up, current pharmacological regimen, and late rejection episodes. RESULTS: Ninety-six patients (70%) survived > or =5 years. Compared to numbers expected based on U.S. population rates, transplant recipients had significantly higher overall prevalences of hypertension (standardized prevalence ratio [SPR]=3.07, 95% confidence interval [CI], 2.35-3.93) and diabetes (SPR=5.99, 95% CI, 4.15-8.38), and higher incidences of de novo malignancy (standardized incidence ratio [SIR]=3.94, 95% CI, 2.09-6.73), non-Hodgkin's lymphoma (SIR=28.56, 95% CI, 7.68-73.11), non-melanoma skin cancer (estimated SIR> or =3.16) and fractures in women (SIR=2.05, 95% CI, 1.12-3.43). Forty-one of 87 (47.1%) patients were obese, and 23 patients (27.4%) had elevated serum cholesterol levels (> or =240 mg/dl, 6.22 mmol/L), compared to 33% and 19.5% of U.S. adults, respectively. Prevalences of heart or peptic ulcer disease were not significantly higher. CONCLUSIONS: Liver transplantation is being performed with excellent 5-year survival. Significant comorbidities exist, however, which appear to be related to long-term immunosuppression.

Prevalence and natural history of cryptorchidism.

OBJECTIVE: A prospective hospital-based cohort study was conducted to determine the prevalence rates of cryptorchidism at birth, 3 months, and 1 year of age. DESIGN: A total of 6935 consecutive male neonates delivered at Mount Sinai Hospital in New York City between October 1987 and October 1990 were examined at birth for cryptorchidism. Standardized examination and classification criteria were used. Infants classified as cryptorchid at birth were reexamined at 3 months and 1 year after the expected date of delivery. RESULTS: Of 6935 neonates assessed at birth, 255 (3.7%) were found to be cryptorchid at birth. The rates were significantly elevated for low birth weight, preterm, small-for-gestational age, and twin neonates. The overall rate had declined to 1.0% by the 3-month assessment and 1.1% at the 1-year assessment. Although the rates at the 1-year assessment tended to be higher for low birth weight and preterm infants, no significant group differences were observed. CONCLUSIONS: Since the prevalence rates in this study are similar to those reported several decades ago, these data provide no evidence that the rate of cryptorchidism has increased either at birth or by 1 year of age. Furthermore, most testes that descend spontaneously do so within the first 3 months after the expected date of delivery.

Recurrence of Crohn's disease in end ileostomies.

: It appears well established that the recurrence rates following operations for Crohn's disease of ileum and colon are higher after anastomotic operations than after an end ileostomy. To obtain further information regarding the rate of recurrence following end ileostomy we reviewed the charts of 182 patients: 117 with involvement of the ileum as well as the colon, and 65 with Crohn's colitis only, who were operated upon at the Mt. Sinai Hospital during 1952-1984. They were followed until death or the first ileostomy revision or the last contact. Of the ileocolitis group, 50 patients (43%), and of the colitis group, nine patients (14%) required an ileostomy revision. Of the 50 with ileocolitis, 34 (29%) and four of the colitis group (6.2%) had revisions done primarily for recurrent Crohn's disease at or near the stoma. The estimated overall cumulative probability of recurrence was 50% twenty years following ileostomy, and was significantly higher in the ileocolitis group than in the colitis group (64% vs. 15%; p < 0.001), with mean follow-up durations of 6.5 and 7.5 years, respectively. The probability of ileostomy revision for any reason was also significantly higher for patients with ileocolitis (74% vs. 34%; p < 0.001). We conclude that the site of initial Crohn's disease plays a role in the recurrence of disease in an end ileostomy, with a better outlook for patients with colonic involvement alone.

Can retrograde perfusion mitigate cerebral injury after particulate embolization? A study in a chronic porcine model.

OBJECTIVE: We assessed the impact on histologic and behavioral outcome of an interval of retrograde cerebral perfusion after arterial embolization, comparing retrograde cerebral perfusion with and without inferior vena caval occlusion with continued antegrade perfusion. METHODS: Sixty Yorkshire pigs (27 to 30 kg) were randomly assigned to the following groups: antegrade cerebral perfusion control; antegrade cerebral perfusion after embolization; retrograde cerebral perfusion control; retrograde cerebral perfusion after embolization; retrograde cerebral perfusion with inferior vena cava occlusion, retrograde cerebral perfusion with inferior vena cava occlusion control, and retrograde cerebral perfusion with inferior vena cava occlusion after embolization. After cooling to 20 degrees C, a bolus of 200 mg of polystyrene microspheres 250 to 750 (microm diameter (or saline solution) was injected into the isolated aortic arch. After 5 minutes of antegrade cerebral perfusion, 25 minutes of antegrade cerebral perfusion, retrograde cerebral perfusion, or retrograde cerebral perfusion with inferior vena cava occlusion was instituted. After the operation, all animals underwent daily assessment of neurologic status until the time of death on day 7. RESULTS: Aortic arch return, cerebral vascular resistance, and oxygen extraction data during retrograde cerebral perfusion showed differences, suggesting that more effective flow occurs during retrograde cerebral perfusion with inferior vena cava occlusion, which also resulted in more pronounced fluid sequestration. Microsphere recovery from the brain revealed significantly fewer emboli after retrograde cerebral perfusion with inferior vena cava occlusion. Behavioral scores showed full recovery in all but one control animal (after retrograde cerebral perfusion with inferior vena cava occlusion) by day 7 but were considerably lower after embolization, with no significant differences between groups. The extent of histopathologic injury was not significantly different among embolized groups. Although no histopathologic lesions were present in either the antegrade cerebral perfusion control group or the retrograde cerebral perfusion control group, mild significant ischemic damage occurred after retrograde cerebral perfusion with inferior vena cava occlusion even in control animals. CONCLUSIONS: Although effective washout of particulate emboli from the brain can be achieved with retrograde cerebral perfusion with inferior vena cava occlusion, no advantage of retrograde cerebral perfusion with inferior vena cava occlusion after embolization is seen from behavioral scores, electroencephalographic recovery, or histopathologic examination; retrograde cerebral perfusion with inferior vena cava occlusion results in greater fluid sequestration and mild histopathologic injury even in control animals. Retrograde cerebral perfusion with inferior vena cava occlusion shows clear promise in the management of embolization, but further refinements must be sought to address its still worrisome potential for harm.

Neurologic outcome after ascending aorta-aortic arch operations: effect of brain protection technique in high-risk patients.

OBJECTIVE: We sought to assess the optimal strategy for avoiding neurologic injury after aortic operations requiring hypothermic circulatory arrest. METHODS: All 717 patients who survived ascending aorta-aortic arch operations through a median sternotomy since 1986 were examined for factors influencing stroke. Temporary neurologic dysfunction was assessed in all patients who survived the operation without stroke since 1993. Multivariate analyses were carried out to determine independent risk factors for neurologic injury. RESULTS: Independent risk factors for stroke were as follows: age greater than 60 years (P <.001; odds ratio, 4.5); emergency operation (P =.02; odds ratio, 2.2); new preoperative neurologic symptoms (P =.05; odds ratio, 2.9); presence of clot or atheroma (P <.001; odds ratio, 4.4); mitral valve replacement or other concomitant procedures (P =.055; odds ratio, = 3.7); and total cerebral protection time, defined as the sum of hypothermic circulatory arrest and any retrograde or antegrade cerebral perfusion (P =.001; odds ratio, 1.02/min). In 453 patients surviving operations without stroke after 1993, independent risk factors for temporary neurologic dysfunction included age (P <.001; odds ratio, 1.06/y), dissection (P =.001; odds ratio, 2.2), need for coronary artery bypass grafting (P =.006; odds ratio, 2.1) or other procedures (P =.023; odds ratio, 3.4), and total cerebral protection time (P <.001; odds ratio, 1.02/min). When all patients with total cerebral protection times between 40 and 80 minutes were examined, the method of cerebral protection did not influence the occurrence of stroke, but antegrade cerebral perfusion resulted in a significant reduction in incidence on temporary neurologic dysfunction (P =.05; odds ratio, 0.3). CONCLUSIONS: The occurrence of stroke is principally determined by patient- and disease-related factors, but use of antegrade cerebral perfusion can significantly reduce the occurrence of temporary neurologic dysfunction.

Risk factors for rupture of chronic type B dissections.

OBJECTIVE: This study was an attempt to determine risk factors for rupture and to improve management of patients with type B aortic dissection who survive the acute phase without operation. METHODS: We studied 50 patients by means of serial computer-generated 3-dimensional computed tomographic scans. All patients who did not undergo operative treatment before the completion of at least 2 computed tomographic scans a minimum of 3 months apart after an acute type B dissection were included in the study. The median duration of follow-up was 40 months (range 0.9-112 months). Only 1 patient died of causes unrelated to the aneurysm during follow-up. Nine patients had fatal rupture (18%); 10 patients underwent elective aneurysm resection because of rapid expansion or development of symptoms, and 31 patients remained alive without operation or rupture. Possible risk factors for rupture in patients in the rupture, operative, and event-free groups were compared, as were dimensional data from first follow-up and last computed tomographic scans. RESULTS: Older age, chronic obstructive pulmonary disease, and elevated mean blood pressures were unequivocally associated with rupture (rupture versus event-free survival, P <.05), and pain was marginally significantly associated. Analysis of dimensional factors contributing to rupture was complicated by the fact that patients who underwent elective operation had significantly larger aneurysms and faster expansion rates than did either of the other groups, leaving comparisons of aneurysmal diameter between groups with and without rupture showing only marginal statistical significance. The last median descending aortic diameter before rupture in the rupture group was 5.4 cm (range 3.2-6. 7 cm). CONCLUSIONS: In an environment in which patients with large and rapidly expanding aneurysms are usually referred for surgical treatment, older patients with chronic type B dissections, especially if they have uncontrolled hypertension and a history of chronic obstructive pulmonary disease, are significantly more likely to have rupture than are younger, normotensive patients without lung disease. Neither the presence of a persistently patent false lumen nor a large abdominal aortic diameter appears to increase the risk of rupture. Overall, our nondimensional data strikingly resemble the natural history of patients with nondissecting aneurysms, suggesting that calculations derived from data on chronic descending thoracic and thoracoabdominal aneurysms would provide an overly conservative individual estimate of rupture risk for patients with chronic type B dissection, who tend toward earlier rupture of smaller aneurysms. A more aggressive surgical approach toward treatment of patients with chronic type B dissection seems warranted.

Some limitations on studies about the relation between gross cystic disease and risk of subsequent breast cancer.

Studies about the relationship between gross cysts and risk of subsequent carcinoma of the breast should be interpreted with caution. When the study material is limited to microscopic review of benign biopsy specimens, there is considerable chance of misclassification of cases both of those with and of those without gross cysts. Moreover, statistical analyses based on internal comparisons of such data tend to separate the influence of gross cysts from that of any associated proliferative disease process. Thus, while they may provide information about whether or not gross cysts identified under a microscope influence the risk of breast cancer, independently of other, associated pathology, they do not address the question of whether or not gross cysts serve as a marker for an increased risk of breast cancer. On the other hand, statistical analyses based on external comparisons do not allow estimates of relative risks associated with gross cysts that are clearly unaffected by other factors related to breast cancer risk. Follow-up data on over 2500 patients who consulted Dr. C. D. Haagensen for gross cystic disease of the breast provide evidence of an increased risk of breast cancer, when compared with an external standard. A microscopic biopsy review of Dr. Haagensen's benign breast cases, with and without GCD, is currently under way to classify the cases in a way that is comparable to the Dupont and Page criteria. It is hoped that a statistical analysis that incorporates these microscopic findings with the clinical information and the gross pathology will shed further light on the role of gross cysts in relation to breast cancer.

Surgery for ulcerative colitis in elderly persons: changes in indications for surgery and outcome over time.

HYPOTHESIS: Medical therapy has changed the indications for surgery over the last 4 decades. Advances in perioperative care have significantly improved the outcome. DESIGN: The medical records of all patients 65 years and older who underwent surgery for ulcerative colitis during a 40-year period were analyzed retrospectively. SETTING: Tertiary referral center. PATIENTS: One hundred thirteen consecutive patients 65 years and older who underwent surgery for ulcerative colitis between January 1, 1960, and June 30, 1999. MAIN OUTCOME MEASURES: Changes in elective and urgent indications for surgery. Changes over time in outcome and the factors that brought about these changes. Predictors of poor outcome in an elderly population with ulcerative colitis. RESULTS: One hundred thirteen patients were divided into 3 cohorts of 38, 38, and 37 consecutive patients admitted to the hospital during the periods 1960 through 1984, 1985 through 1993, and 1994 through 1999, respectively. Indications for surgery and morbidity and mortality rates have changed with time. Dysplasia has replaced carcinoma as a major indication for elective surgery (P =.001). Toxic megacolon has become significantly less common as an indication for urgent surgery (P =.001). Surgery-associated adverse outcomes have decreased significantly from 50% (13% deaths, 37% major complications) to 27% (3% deaths, 24% major complications) (P =.04). Male sex, an albumin level of 2.8 g/dL or less, and urgent surgery were found to be independent predictors of poor outcome. CONCLUSIONS: In our referral center, the indications for urgent and elective surgery have changed during the past 4 decades from toxic megacolon and carcinoma, to disease refractory, to medical therapy and dysplasia, respectively. Morbidity and mortality have decreased dramatically over time. Urgent procedures, low levels of albumin, and male sex are all predictors of poor outcome.

Predictors of adverse outcome and transient neurological dysfunction after ascending aorta/hemiarch replacement.

BACKGROUND: This study was undertaken to determine predictors of adverse outcome and transient neurological dysfunction after replacement of the ascending aorta with an open distal anastomosis. METHODS: All 443 patients (300 male, median age 63) undergoing replacement of the ascending aorta with an open distal anastomosis between 1986 and 1998 were included in the analysis. The ascending aorta alone was replaced in 190 (42.9%); 253 (57.1%) also had proximal arch replacement. Median hypothermic circulatory arrest (HCA) time was 25 minutes (range 12 to 68). Either death or permanent neurological dysfunction were considered adverse outcome (AO). RESULTS: Adverse outcome occurred in 11.5% (51 of 443) of patients overall: in 7.4% of elective (20 of 269) or urgent (4 of 54) operations, but in 17% (19 of 113) of emergencies. Multivariate analysis of the group as a whole revealed that significant (p < 0.05) independent preoperative predictors of AO were age greater than 60 [odds ratio (OR) 2.2], hemodynamic instability (OR 2.7), and dissection (OR 1.9). For the 435 operative survivors, procedural variables predictive of AO were contained rupture (OR 2.8) and HCA time (OR 1.03/min). When only the 271 elective patients were analyzed separately, the need for a concomitant procedure (p = 0.009, OR 3.6) and HCA time (p = 0.002, OR 1.06/min) were the only predictors of AO in multivariate analysis. Transient neurological dysfunction (TND) occurred in 86 of 392 patients (22%). Significant predictors of TND for all patients without AO were age (OR 1.06/y), HCA time (OR 1.04/min), coronary artery disease (OR 2.2), hemodynamic instability (OR 3.4), and acute operation (OR 2.2). Survival of discharged patients was 93% at 1 year and 83% at 5 years. CONCLUSIONS: Early elective operation and shorter HCA time during ascending aorta/hemiarch surgery will reduce both AO and TND.

Retrograde cerebral perfusion enhances cerebral protection during prolonged hypothermic circulatory arrest: a study in a chronic porcine model.

BACKGROUND: This study was undertaken to confirm earlier findings that retrograde cerebral perfusion (RCP) can improve cerebral outcome after prolonged hypothermic circulatory arrest (HCA), and to determine whether RCP with inferior vena caval occlusion, which is more effective in removing particulate emboli, is superior to conventional RCP in enhancing cerebral protection. METHODS: Sixty-two pigs (27 to 30 kg) were randomly assigned to undergo one of the following for 90 minutes at 20 degrees C: antegrade cerebral perfusion (ACP); conventional RCP (RCP); RCP with occlusion of the inferior vena cava (RCP-O), or HCA with the head packed in ice. RCP flow was regulated to a sagittal sinus pressure of 20 mm Hg. Hemodynamic, electrophysiologic, and metabolic monitoring were carried out until 4 hours after rewarming, daily behavioral and neurologic assessments until elective sacrifice on day 7, and histologic analysis of the brain after death. RESULTS: Complete behavioral recovery was seen in all surviving animals by day 5 after ACP or RCP, but in only 83% after RCP-O and 50% after HCA (p = 0.001). A histopathologic score of 2 or more, indicating more than mild injury, was not found in any animal after ACP, in 27% after RCP, in 47% after HCA, and in 68% after RCP-O (p = 0.002). The median oxygen consumption was 6.66 mL/min after ACP, 1.37 mL/min with RCP, and 1.02 mL/min with RCP-O (p < 0.0001). The median amount of fluid sequestered was 2,450 mL after RCP-O, 760 mL after RCP, and -200 mL after ACP (p < 0.0001). CONCLUSIONS: Conventional RCP without inferior vena caval occlusion results in a significantly better outcome than RCP-O after prolonged HCA, despite more efficient cerebral perfusion during RCP-O, and also provides cerebral protection superior to prolonged HCA alone, but care must be taken during its implementation to minimize cerebral edema and other possible causes of retroperfusion-related cerebral injury.

Favorable outcome after composite valve-graft replacement in patients older than 65 years.

BACKGROUND: Concomitant surgical replacement of the aortic valve and ascending aorta is an ideal treatment for aortic root aneurysms, but there may be hesitation in its use in older patients, despite their known increased risk of rupture. This study was conducted to examine our results in 84 patients older than 65 years undergoing elective aortic root resection with composite valve-graft replacement. METHODS: Eighty-four patients older than 65 years were operated on between June 1987 and August 1998. Median age was 74 years (range, 66 to 89 years), and 57 patients were men. Seventeen patients were undergoing reoperation. Aortic insufficiency was present in 70 patients. Forty-seven patients received a conduit using a bioprosthesis, whereas in 37 a mechanical valved conduit (St. Jude) was used. The ascending aorta alone was replaced in 23 patients; 50 had hemi-arch replacement, and in 11 the entire aortic arch was replaced. RESULTS: Hospital mortality was 8.3% (7 of 84). Sixteen late deaths (19%) were noted during a median follow-up of 3.2 years (range, 0 to 10 years). Only one late death was aorta-related. The incidence of thrombotic or hemorrhagic complications was 2.1/100 patient-years, with equal frequency for both mechanical and bioprosthetic valves. CONCLUSIONS: We conclude that composite valve-graft replacement in elderly patients results in a low operative mortality, yields excellent long-term survival, and averts fatal aneurysm rupture in this high-risk population.

Pathogenesis of spinal cord injury during simulated aneurysm repair in a chronic animal model.

The pathogenesis of paraplegia after repair of thoracic aortic aneurysms is controversial. Using direct spinal cord evoked potential monitoring, critical intercostal arteries (CICA) were identified to evaluate the impact of backbleeding and ligation versus that of preservation during simulated aneurysm repair. Thirty pigs (40 kg) were randomly assigned to one of five groups. In groups 1 through 4, a thoracic segment containing CICA was cross-clamped for 60 minutes and distal aortic perfusion was provided by a centrifugal pump. In groups 1 and 2, the thoracic segment was vented, maintaining segment pressure at 0 mm Hg; CICA were ligated in group 1 and preserved in group 2. Thoracic segment was perfused at 70 mm Hg in groups 3 and 4; CICA were ligated in group 3 and preserved in group 4. Critical intercostal artery ligations were performed at the end of the cross-clamp period. In group 5 simple cross-clamping at the left subclavian artery was performed as a control. The combination of venting and ligation of CICA correlated with impaired neurologic outcome according to Tarlov's score (median, 1.5 in group 1 versus 3 in group 2; p = 0.015), indicated by a significant difference in median values of direct spinal cord evoked potential amplitude (expressed as a fraction of baseline values) at 120 minutes after cross-clamping (0.76 in group 1 versus 0.98 in group 2; p = 0.0082).(ABSTRACT TRUNCATED AT 250 WORDS)

Prospective study of the natural history of thoracic aortic aneurysms.

BACKGROUND: The decision whether or not to recommend resection of moderately large descending thoracic and thoracoabdominal aneurysms requires weighing the relatively high mortality and significant risk of paraplegia associated with operation against the likelihood that the aneurysm will rupture spontaneously, with an almost invariably fatal outcome. To better define the risk of aneurysm rupture, we undertook a prospective study of patients who had not had operation on their moderately large descending thoracic and thoracoabdominal aneurysms. METHODS: Patients were enrolled at the time of their second computed tomographic scans: three-dimensional computer-generated reconstructions allowed determination of several dimensional parameters for each study, including diameters and cross-sectional areas at the site of maximal dilatation in the descending aorta and in the abdomen as well as total thoracoabdominal surface area. Comparisons of serial studies permitted calculation of yearly rates of change in these dimensions. RESULTS: Of 114 patients, 8 died of causes unrelated to the aneurysm, 26 died of rupture, 20 met previously determined criteria for operation, and 60 survived without operation or rupture. Multivariate regression analysis identified maximal diameter in the descending and in the abdominal aorta as independent risk factors for rupture, as well as older age, the presence of even uncharacteristic pain, and a history of chronic obstructive pulmonary disease. A piecewise exponential model enabled construction of an equation allowing calculation of rate of rupture in patients in whom the values of the risk factors are known, and also of the probability of rupture in a given individual over a specified time interval. CONCLUSIONS: Because using this equation--based on easily determined risk factors (age, pain, chronic obstructive pulmonary disease, maximal thoracic and maximal abdominal aortic diameter)--allows the risk of aneurysm rupture within a given interval to be estimated fairly accurately for each individual patient, it is our current practice to recommend operation when the calculated risk of rupture within 1 year exceeds the anticipated mortality of elective operation, rather than relying on general operative guidelines based almost exclusively on aneurysm size.

Retrograde cerebral perfusion during thoracic aortic surgery and late neuropsychological dysfunction.

OBJECTIVE: Retrograde cerebral perfusion (RCP) is commonly used in thoracic aortic surgery, ostensibly to provide metabolic support, maintain cerebral hypothermia and/or wash out particulate emboli. We tested the hypothesis that RCP would affect neuropsychological outcome in a clinical cohort. METHODS: Ninety-four patients undergoing elective thoracic aortic repairs requiring deep hypothermic circulatory arrest consented to participate in this study. These patients underwent preoperative neuropsychological evaluation and comprise the reference group. Fifty-six of these patients also underwent neuropsychological evaluation several weeks postoperatively, 12 of whom (21%) had RCP. The neuropsychological domains tested were attention, processing speed, memory, executive function, and fine motor function. A global assessment of impairment, negative neuropsychological outcome (NNO), was defined as a postoperative decrease in function in two or more neuropsychological domains for patients with at least three domains tested both pre- and postoperatively (n=48). The relationship of three potential predictors (RCP, cerebral ischemia time and patient age) to negative outcomes was analyzed using Wilcoxon two-sample tests, chi(2) tests, Mantel-Haenszel tests and multiple logistic regression. P<0.05 was considered significant. RESULTS: Memory dysfunction and NNO had strong associations with RCP. This effect remained significant when controlling separately for age and cerebral ischemia time. CONCLUSIONS: The effects of RCP are difficult to distinguish from those of age and prolonged cerebral ischemia time, because complex thoracic aortic repairs are associated with advanced age, prolonged cerebral ischemia and use of RCP. Despite this limitation, these preliminary data indicated that RCP had no beneficial effect (and most likely a negative effect) upon cognitive outcome.

Is aortic surgery using hypothermic circulatory arrest in octogenarians justifiable?

OBJECTIVE: This study was undertaken to analyze the risk of mortality and neurological complications after aortic surgery requiring hypothermic circulatory arrest (HCA) in octogenarians. METHODS: All patients of >80 years at the time of aortic surgery requiring HCA since 1988 were examined. Of 51 patients, 23 were male; the median age was 83. Twenty-six (51%) had proximal repair; the arch was replaced in eight (16%), and 17 (33%) had descending aorta repair. Eleven (22%) were emergencies. Multivariate analysis was carried out to determine the risk factors for in-hospital mortality and/or stroke (adverse outcome) using variables with P<0.1 after univariate analysis. RESULTS: The hospital mortality was 16%. Five patients suffered strokes (9.8%): only one survived >6 months, and three died before discharge. The overall adverse outcome was 22%, but elective operation was associated with much better results, with an adverse outcome of only 3.6% after operations via a median sternotomy. Adverse outcome was strikingly higher with more distal resections via a left thoracotomy: 47 vs. 8.8% for ascending aorta/arch resections (P=0.003). Emergency operation via a lateral thoracotomy was associated with a prohibitively high adverse outcome. Twenty-nine patients (73%) had temporary neurological dysfunction (TND). Multivariate analysis revealed emergency operation (P=0.01; odds ratio (OR), 10.6) and operations via a lateral thoracotomy (P=0.008; OR, 11) as independent preoperative predictors of adverse outcome. The overall survival was 66% at 2 years and 39% at 5 years, compared with 85 and 52% among age- and sex-matched controls. CONCLUSIONS: Aortic surgery utilizing HCA in octogenarians can be performed with an acceptable risk of mortality and stroke. From the evidence in this study, it seems that elective aneurysm repair via a median sternotomy can be undertaken for the usual indications, even in octogenarians. However, the enhanced vulnerability of the brain in the elderly is reflected by a high early mortality following stroke, and a high incidence of TND. Emergency operations increase the possibility of adverse outcome dramatically, and patients who require a lateral thoracotomy are at significantly higher risk than those operated via a median sternotomy.

Cyclosporine A as a potential neuroprotective agent: a study of prolonged hypothermic circulatory arrest in a chronic porcine model.

OBJECTIVE: To assess whether Cyclosporine A (CsA) or cycloheximide (CHX) can reduce ischemia-induced neurological damage by blocking apoptotic pathways, we assessed their effects on cerebral recovery in a chronic animal model of hypothermic circulatory arrest (HCA). METHODS: Twenty-eight pigs (28-33 kg) underwent 90 min of HCA at 20 degrees C. In this blinded study, animals were randomized to placebo (n=12), 5 mg/kg CsA (n=8), given intravenously before and subcutaneously for 7 days after HCA, or a single dose of 1 mg/kg CHX (n=8), given after weaning from cardiopulmonary bypass. Hemodynamics, intracranial pressure (ICP) and neurophysiological data (EEG, SSEP) were assessed for 3 h after HCA; early behavioral recovery was scored, and neurological/behavioral evaluation (9=normal) was carried out daily until elective sacrifice on postoperative day (POD) 7. Brains were selectively perfused and evaluated histopathologically for apoptosis. RESULTS: Basic hemodynamic data revealed no differences between CsA or CHX and control groups. ICP was significantly lower throughout rewarming (P=0.009) and reperfusion (P=0.05) in the CsA group. EEG recovery 3 h after HCA was observed in four of eight CsA animals but in only 1 of 12 controls (P=0.11) and one of eight CHX animals; cortical SSEP recovery also seemed faster in CsA animals, but failed to reach significance. Some early recovery scores were significantly better in the CsA group, and daily behavioral scores were consistently and significantly higher in the CsA-treated animals from POD1 through POD4. CONCLUSIONS: The data indicate that treatment with Cyclosporine A but not cycloheximide has a positive effect on cerebral recovery following HCA. Whether CsA results in inhibition of neuronal apoptosis, and/or inhibits release of cytokines and thereby reduces postischemic cerebral edema remains to be elucidated. The neuroprotective effect of CsA, if confirmed in further studies, would make its clinical application conceivable.