The experimental relationship between leaflet clearance and orientation of the St. Jude Medical valve in the mitral position.

The optimal orientation of the St. Jude Medical mechanical prosthesis in the mitral position has not yet been determined. While in the majority of cases the valve can perform satisfactorily regardless of valve orientation, certain circumstances can increase the risk of leaflet impingement. These valves are commonly implanted with their leaflets oriented parallel to the anatomic axis of the native leaflets (anatomic orientation) or with their prosthetic leaflets perpendicular to the axis of the native leaflets (antianatomic orientation). To determine the influence of valve orientation on the clearance from the prosthetic leaflet to the posterior ventricular wall, we calculated the clearances on all available models of the St. Jude Medical mitral valve. Clearances were computed from measurements of valve dimensions with use of an electronic caliper. In all cases the clearance in antianatomic orientation was at least 49.5% greater (mean 59%, range 49.5% to 77.5%) than in anatomic orientation.

Efficacy of combined coronary revascularization and valve procedures in octogenarians.

From January 1982 to October 1991, 42 consecutive patients 80 years of age and older underwent a combined cardiac procedure with coronary revascularization and valve repair or replacement. There were 20 women and 22 men. Mean age at operation was 82.8 years (range, 80 to 89.7 years). Twenty-seven patients (64%) were in New York Heart Association (NYHA) functional class III or IV preoperatively. Six patients (14.3%) had undergone previous cardiac procedures. There were six hospital deaths (14.3%). The only significant preoperative risk factor identified for the event hospital death was aortic insufficiency (p = 0.005). The 36 hospital survivors were followed up at a mean of 21.1 months after hospital discharge. There were nine (21%) late deaths occurring at a mean of 21.3 months postoperatively: two from acute myocardial infarctions and seven from chronic heart failure. Survival analysis indicated that higher preoperative NYHA class (p = 0.0003), hypertension (p = 0.015), hypercholesterolemia (p = 0.03), and elevated left atrial/left ventricular gradient (p = 0.04) were incremental risk factors for overall mortality. The actuarial survival at 40 months was 51.9%, with no significant difference as compared with an age-, sex-, and race-matched population. Of the 27 late survivors, 26 were in NYHA class I or II. We conclude that octogenarians may undergo complex cardiac surgical procedures with an expectation of an acceptable mortality rate and significant improvement in their functional status. These results must be taken into consideration in light of reported strategies to ameliorate health-care costs by limiting availability of complex medical care to the elderly.

The impact of intraoperative autotransfusion on cardiac surgery. A prospective randomized double-blind study.

The effect of intraoperative autotransfusion during coronary artery bypass grafting was studied in a randomized double-blind trial involving 38 patients. Nineteen patients had the collected RBCs washed and autotransfused (autotransfusion group), while the remaining patients had their washed cells discarded (control group). Postoperative hemoglobin and hematocrit values were similar. Exposure to banked blood was markedly decreased in the autotransfusion group compared with the control group. In addition, the mean volume of banked packed RBCs transfused per patient was significantly less in the autotransfusion group compared with the control group. Platelet utilization also was markedly decreased in the autotransfusion group. Cryoprecipitate and fresh frozen plasma utilization also was less in the autotransfusion group than in the control group, but this did not reach statistical significance. We conclude that the intraoperative use of autotransfusion decreases the volume of homologous blood products transfused, which results in reduced exposure of the patients to banked blood products.

The impact of aprotinin on coronary artery bypass graft patency.

STUDY DESIGN: Aprotinin has recently been shown to reduce postoperative bleeding and transfusion requirements associated with coronary artery bypass grafting. One concern with its use, however, is that it may have a deleterious effect on graft patency because it promotes hemostasis. Forty-seven patients undergoing coronary artery bypass. Forty-seven patients undergoing coronary artery bypass grafting were enrolled in a prospective, randomized double-blind trial of aprotinin to determine the effect of this agent on postoperative bleeding, transfusion requirements, renal function, and graft patency. The study group was comprised of the 32 patients who underwent technically adequate ultrafast CT scans 6 to 8 weeks postoperatively to determine graft patency. Sixteen patients received aprotinin (aprotinin group) and 16 received placebo (control group). RESULTS: Demographic and operative descriptors were comparable between groups. Postoperative mediastinal and chest tube drainage in the aprotinin group was significantly less than that in the control group (722 vs 1,540 mL; p = 0.0006) and the mean blood transfusion requirements were less, but this did not reach significance (125 vs 297 mL; p = 0.42). Analysis of graft patency by patients revealed that 5 patients in the aprotinin group (31%) had at least one occluded graft, while none of the patients in the control group had an occluded graft (p = 0.04). Analysis by graft revealed that 38 of 43 grafts placed in the aprotinin group were patent, while all 38 grafts placed in the placebo group were patent (88.4 vs 100%; p = 0.057). There was no difference in the incidence of myocardial infarction, renal dysfunction or hematologic indexes at discharge between the groups, or evidence of other thrombotic complications. CONCLUSION: We conclude that high-dose aprotinin is effective in reducing hemorrhage after coronary artery bypass grafting. However, its routine use should be approached cautiously due to its possible adverse effects on graft patency.

Early and late-phase events after valve replacement with the St. Jude Medical prosthesis in 1200 patients.

From May 1982 to August 1991, 1200 patients underwent valve replacement with the St. Jude Medical (St. Jude Medical, Inc., St. Paul, Minn.) valve: 615 men (51%) and 585 women, mean age 58 years. Preoperatively, 830 patients (69%) were in functional class III or IV. A total of 611 patients (51%) had the aortic valve replaced, 490 (41%) the mitral valve, 2 (0.2%) the tricuspid valve, and 97 (8%) multiple valves. There were 81 hospital deaths (6.8%). Risk factors included older age (p = 0.0001), female gender (p = 0.02), higher preoperative left ventricular end-diastolic pressure (p = 0.05), previous cardiac operation (p = 0.003), longer aortic crossclamp time (p = 0.0001), and longer cardiopulmonary bypass time (p = 0.0001). Follow-up was 98% complete (3153 patient-years). There were 152 late deaths; 32 (21%) were considered valve-related: six thromboembolism, four valve thrombosis, five anticoagulant-related hemorrhage, eight prosthetic valve endocarditis, one paravalvular leak, and seven sudden death. The 5-year actuarial survival was 75%. Risk factors for late death included older age (p = 0.03), lower preoperative ejection fraction (p = 0.005), longer aortic crossclamp time (p = 0.001), longer cardiopulmonary bypass time (p = 0.0001), previous cardiac operation (p = 0.02), and higher preoperative functional class (p = 0.0001). Actuarial freedom at 5 years from major thromboembolic events and anticoagulant-related hemorrhage was 97% and 95%, respectively. This value for valve thrombosis was 99%, for reoperation 96%, for prosthetic valve endocarditis 98%, and for paravalvular leak 96%. Actuarial freedom from all valve-related events and valve-related death at 5 years was 74% and 94%, respectively. We conclude that the low incidence of valve-related events and low mortality supports the continued use of the St. Jude Medical valve.

Esophageal perforation in a patient with acquired immunodeficiency syndrome.

Infection with Mycobacterium tuberculosis is frequently found in patients with acquired immunodeficiency syndrome and can result in diffuse lymphadenopathy from disseminated disease. A case is presented of esophageal erosion and perforation secondary to mediastinal lymph node enlargement from Mycobacterium tuberculosis in a patient positive for human immunodeficiency virus. Emergent surgical intervention required resection of the perforated esophagus, end-cervical esophagostomy, gastrostomy, and feeding jejunostomy. Long-term prognosis is poor owing to acquired immunodeficiency syndrome, therefore, reconstruction at a later date is uncertain.

Left ventricular pseudoaneurysm with hemoptysis.

A 53-year-old man who had previously undergone resection of a left ventricular aneurysm was admitted because of hemoptysis. Preoperative evaluation with computed tomographic scan and cardiac catheterization demonstrated a pseudoaneurysm of the inferior ventricular wall measuring 16 cm in diameter with protrusion into the left hemithorax. The neck of the pseudoaneurysm was a defect in the ventricular wall extending from the base of the mitral valve annulus to the insertion of the posterior papillary muscle. Operative repair was performed using an albumin-coated, low-porosity Dacron patch.

Chronic type A aortic dissection: an unusual complication of cocaine inhalation.

Acute aortic pathology temporally related to cocaine inhalation may lead to frank rupture or acute aortic dissection. This is a report of an unusual case of a 43-year-old man who presented 9 weeks after experiencing a tearing sensation in his chest while smoking cocaine. The diagnosis was chronic type A aortic dissection with 4+ aortic insufficiency. The successful surgical management included resuspension of the aortic valve and placement of a Dacron tube graft in the ascending aorta such that flow was maintained distally in both the true and false lumens.

Management of an innominate artery aneurysm during an open heart operation.

A 76-year-old woman was found to have a 4 x 2.5-cm saccular aneurysm at the origin of the innominate artery at the time of a reoperative open heart operation. The operative procedure was modified to include repair of the aneurysm with a Dacron patch. During the period of innominate artery occlusion, the patient was cooled to 25 degrees C and the mean arterial pressure was maintained at 90 mm Hg to maximize cerebral protection.

Factors affecting mitral valve reoperation in 317 survivors after mitral valve reconstruction.

From a very heterogeneous group of 340 patients undergoing mitral valve reconstruction from 1969 through 1988, 313 hospital survivors were analyzed for factors affecting the occurrence of reoperative mitral valve procedures related to native mitral valve dysfunction. Follow-up was 100% and extended from 1 year to 20 years (mean follow-up, 7.2 years). Sixty-three patients (18.5% of the 340) required mitral valve reoperation at a mean postoperative interval of 6 years (range, 1 to 15 years). Incremental risk factors analyzed for the event late mitral valve failure included age, sex, preoperative New York Heart Association class, cause of valvular disease, pathophysiology of the mitral valve, previous mitral valve operation, mitral valve pathology, and estimation of mitral valve function at operation after repair. Mitral valve pathophysiology affected the actuarial freedom from mitral valve replacement (p = 0.023 [log-rank]). Actuarial freedom from mitral valve reoperation was 90% at 5 years and 80% at 8 years in patients who had either pure mitral regurgitation or isolated mitral stenosis compared with 80% and 72% at 5 and 10 years, respectively, in patients who had mixed mitral stenosis and regurgitation (p = 0.023). Patients undergoing late reoperation were younger (51.7 +/- 1.56 years [+/- the standard error of the mean]) than those not having reoperation (p less than 0.0003). Durability of the repair was less in patients with rheumatic heart disease (p less than 0.025) and greater in patients with ischemic heart disease (p less than 0.004). Seventy-three percent of patients undergoing reoperation had concomitant operations compared with 68% of those not having reoperation (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of low-pressure versus standard-pressure fixation Carpentier-Edwards bioprosthesis.

Intermediate-phase clinical results of 51 low-pressure (LP) and 234 standard-pressure (SP) fixation porcine Carpentier-Edwards (CE) valves implanted between 1977 and 1991 were compared for valve-related events. Group similarities included New York Heart Association functional class, ejection fraction, and sex. Patients with SP valves were younger (mean age, 58 versus 68 years; p = 0.0001). There were 20 in-hospital deaths (8.6%) in the SP valve group and 5 (9.8%) in the LP valve group (p = 0.79). Follow-up was 99%, with a mean of 104 months in the SP valve group versus 55 months in the SP valve group (p = 0.0001). The actuarial survival rate was 48.2% and 22.3% at 10 and 15 years, respectively, in the SP valve group and 34.1% at 10 years in the LP valve group (p = 0.42). Freedom from events at 5, 10, and 15 years in the SP valve group and at 5 years in the LP valve group was as follows: for late valve-related events, 86.3%, 51.4% and 20.2%, respectively, in the SP valve group versus 85% in the LP valve group (p = 0.44); for valve-related death, 96.4%, 93.6%, and 87.3% in the SP valve group versus 100% in the LP valve group (p = 0.20); for structural valve failure, 96%, 68%, and 35% in the SP valve group versus 100% in the LP valve group (p = 0.09); and for reoperation, 95%, 61%, and 30% in the SP valve group versus 92% in the LP valve group (p = 0.82). In conclusion, this study revealed no significant statistical difference between LP and SP valves. In the LP valve group, structural valve failure/valve-related death was not observed, perhaps indicating a more favorable result. Absolute verification of this trend awaits long-term follow-up.

Cryopreserved allograft veins as alternative coronary artery bypass conduits: early phase results.

Traditional autologous conduits are sometimes unavailable or unsuitable to permit total revascularization during coronary artery bypass grafting. In these patients the results of using nonautologous alternative conduits has been disappointing. Encouraged by the excellent long-term results seen with cryopreserved allograft valves, a clinical protocol was developed to evaluate the use of a commercially cryopreserved allograft saphenous vein (CPV). Our protocol consisted of using CPV when left internal mammary arteries and autologous saphenous vein grafts were unavailable or unsuitable for complete revascularization. Blood group (ABO) typed CPVs were thawed and implanted as required using standard surgical techniques. From December 1989 through June 1991, 19 of 1,602 patients who underwent coronary revascularization had CPVs implanted (1.2%). There were no operative deaths. An attempt was made to evaluate the patency of all grafts with coronary arteriography or ultrafast computed tomographic scans. Fourteen patients were available for patency evaluation. Patency rate in the 14 patients studied at a mean of 7 +/- 2 months (range, 2 to 16 months) were: internal mammary artery, 93% (14/15); saphenous vein graft, 80% (4/5); and CPV, 41% (7/17). The patency of the CPV was significantly less than the patency rate for the saphenous vein and internal mammary artery (p = 0.004). We conclude that the short-term patency rate of CPVs is inferior to that of autologous vessels. Due to its poor patency, we recommend that CPV should only be used when no other autologous conduit is available.

Actuarial survival and other events following valve surgery in octogenarians: comparison with an age-, sex-, and race-matched population.

From January 1973 to December 1989, 54 patients over 80 years of age underwent an intracardiac repair which included a cardiac valve operation. There were 21 males and 33 females. Mean age at operation was 82 years, range 80-89 years. Fifty-two patients (96%) were in New York Heart Association functional class III or IV preoperatively. Six patients had undergone previous valve surgery (11%). There were eight hospital deaths (14.8%). Risk factors for hospital death included older age at repair (p = 0.008), increased total cardiopulmonary bypass time (p = 0.06), and, possibly, smaller aortic valve prosthesis (p = 0.10). All 46 hospital survivors were followed up at a mean of 28.8 months after hospital discharge. There were 11 late deaths (23.9%), occurring at a mean of 32.3 months postoperatively. Survival analysis indicated that increased age (p = 0.06) and increased pulmonary artery diastolic pressure preoperatively (p less than 0.07) were multivariate risk factors for overall mortality. Actuarial survival at 5 years was 44%, with no difference from survival in an age-, sex-, and race-matched population. We conclude that octogenarians in the modern era have good chance for survival following valvular surgery. As hazards for full anticoagulation were low in this series, if valve repair is not feasible, we presently recommend the use of mechanical valves in the elderly to reduce the requirement for late reoperation due to bioprosthesis degeneration.

Evaluation of cyropreserved internal thoracic artery as an alternative coronary graft: evidence for preserved functional, metabolic and structural integrity.

The internal thoracic artery (ITA) is the conduit of choice for coronary artery bypass grafting (CABG). This study, utilizing a canine model, evaluates cryopreserved ITA. Sixteen ITAs were harvested and cryopreserved according to United CryoInstitute protocol. Test conduits, 5 cm long and 4 mm mean diameter, were anastomosed to the ligated carotid artery of an unmatched mongrel recipient, above and below the site of native artery ligation. Graft patency was assessed by angiography at 14 days (early) and 980 days (late) postoperatively. Catheterization of the 16 vessels identified three (18%) early and one (6%) late graft occlusion. Ninety days postoperatively, each dog was killed and the graft harvested for histopathological and functional evaluation. Morphologic evaluation, using conventional staining, showed preserved cellular structure, decrease in smooth muscle cells and distorted endothelial layer. Immunocytochemistry, using an antibody against prostacyclin (PGI2), detected PGI2 immunoactivity in the ITA smooth muscle cells. An in vitro assay performed on the arterial rings confirmed preserved functional integrity of the vascular endothelium and smooth muscle. These findings suggest that cryopreserved ITA may have potential as a substitute graft, in devising conduit strategies for primary or reoperative coronary bypass surgery.

Demographic changes in coronary artery bypass surgery and its effect on mortality and morbidity.

Over the past 4-5 years, possibly with the advent of percutaneous transluminal coronary angioplasty (PTCA), there has been a changing patient population for coronary artery bypass surgery (CABS) with a gradual increase in the operative mortality. In an attempt to analyze the changing demographics in patients undergoing CABS and its effect on operative mortality, we analyzed data from 5536 consecutive patients undergoing isolated CABS. There was 4151 patients less than 70 years of age and 1385 patients greater than 70 years. Reoperative CABS procedures were performed in 385 patients, and CABS for post infarction unstable angina pectoris was performed in 578 patients. During the same time period, 2910 patients underwent PTCA. The mean age of bypass patients was 68.5 years with 38% being 70 years or older. The left ventricular ejection fraction in patients undergoing CABS averaged 38%. The average number of bypasses performed was 3.1. In comparison, patients presenting for PTCA were younger (average age 55), had normal ejection fractions (average 55%) and were predominantly treated for single or double vessel disease. The hospital mortality for elective CABS in patients less than 70 years of age was 1.8%, for reoperative CABS 3.6%, for post infarction unstable angina pectoris 4%, and for patients greater than 70 years 8%, for a combined operative mortality of 4.8%. These data suggest that because of the increasing number of elderly patients (greater than 70 years of age), and the increasing number of reoperative CABS cases and acute myocardial infarction patients with unstable angina pectoris presenting for CABS, the operative mortality will continue to rise.

Valve-related events and valve-related mortality in 340 mitral valve repairs. A late phase follow-up study.

To assess the early and late valve-related events, 340 consecutive patients undergoing mitral valve repair from 1969 to 1988 were evaluated. Follow-up was complete, with a mean of 7.5% years and range from 2 to 22 years (cumulative 2456 patient-years). There were 221 (65%) female patients. Rheumatic valvular disease was present in 246 (68%) patients. The remaining patients had ischemic or congenital valve disease, floppy valve or infective endocarditis. At surgery, 47% of the patients had pure mitral incompetence, 43% had mixed mitral stenosis and incompetence and 10% had predominant mitral stenosis. Seventy-three percent of the patients were in functional class III or IV. Twelve percent had had prior heart surgery. Concomitant valve procedures including coronary revascularization were performed in 62.3%. There were 23 hospital deaths (6.8%) but only 3 of these (0.8%) were valve-related in patients who died at reoperation for valve repair failure. There were 4 other early repair failures who survived early reoperation. Of the 317 hospital survivors, there were 127 late deaths, and an actuarial survival of 44 +/- 3.7% (70% CL) at 14 years. Of these, 13 were valve-related or 0.5% patient-year. Late events included thromboembolism (TE) 1% patient-year, anticoagulant bleeding 0.4% patient-year, infective endocarditis (IE) 0.2% patient-year and late reoperation for mitral valve repair failure in 63 patients or 2.8% patient-year. At the late follow-up, 88% of the hospital survivors were in functional class I or II.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of the need for tricuspid valve replacement: value of preoperative right ventricular angiocardiography.

Of 530 patients undergoing tricuspid valve surgery from January 1, 1961 through December 31, 1987, those 362 patients having had preoperative right ventricular angiocardiography were studied. Mean age was 58.5 years. There were 71 males and 291 females. Tricuspid valve replacement (TVR) was performed in 126 (34.8%), and 236 underwent tricuspid valve repair (65.2%). The predominant pathology was combined tricuspid insufficiency and stenosis in 18 patients (4.9%), and isolated tricuspid insufficiency in 344 (95.1%). There were no complications related to the right ventriculogram. Preoperative angiographic severity of tricuspid valve incompetence was grade 1 in 23 patients (6.4%), grade 2 in 65 (17.9%), grade 3 in 109 (30.1%), and grade 4 in 165 (45.6%). Intraoperative assessment of the severity of tricuspid valve incompetence correlated 72% of the time with the preoperative angiographic assessment, in those patients with more severe degrees of incompetence (grade 3+ or 4+), p (X 2) less than 0.001. Increasing severity of preoperative angiographic triscuspid valve incompetence was associated with the requirement for TVR (vs. repair), p (X 2) = 0.0002. In conclusion, preoperative right ventricular angiography is a useful method for assessing tricuspid valve function and may predict the requirement for TVR in patients undergoing tricuspid valve surgery.

Normothermic retrograde cardioplegia is effective in patients with left ventricular hypertrophy. A prospective and randomized study.

Twenty patients with left ventricular hypertrophy (LVH) undergoing isolated aortic valve replacement were prospectively randomized to receive either continuous retrograde normothermic (n = 8) or intermittent retrograde hypothermic (n = 12) methods of myocardial protection. Biopsies of the left ventricular septum were evaluated for ultrastructure and assayed for ATP. There was no mortality, no requirement for intra-aortic balloon pump nor neurological events in any of the patients from either group. Myocardial ATP (warm 23.2 +/- 1.8 nmol/mg protein; cold 22.4 +/- 1.2 nmol/mg protein; p = 0.72) and myocardial CPK-MB (warm 43.6 +/- 5.2 U/l; cold 39.0 +/- 2.5 U/l; p = 0.67) were not significantly different. Ultrastructure was generally well preserved in the biopsies from both groups, with the exception of one patient in the normothermic group. Systemic lactate sampled after 40 minutes of cardiopulmonary bypass was significantly higher in the normothermic group (warm 3.4 +/- 0.27 mmol/l; cold 2.3 +/- 0.21 mmol/l; p = 0.01), however, the myocardial lactate production was not significantly different between the two groups (extraction ratio; warm 0.01 +/- 0.3; cold 0.13 +/- 0.1; p = 0.45). We conclude that the continuous normothermic retrograde method of myocardial protection is effective in patients with left ventricular hypertrophy; however, the higher systemic lactate levels using this technique raises concerns regarding the adequacy of systemic perfusion at 37 degrees C.

Early and late phase events following bioprosthetic tricuspid valve replacement.

From 1961 through 1987, 9,247 patients underwent an intracardiac repair for valvular heart disease. Five hundred thirty patients had a procedure that included a tricuspid valve operation (6%), with tricuspid valve replacement performed in 175 patients (2%), of whom 154 had a bioprosthetic valve implanted (1.7%). These 154 patients with a bioprosthetic valve in the tricuspid position are the subject of this review. There were 27 males and 127 females. Ages ranged from 10 to 75 years. There was tricuspid valve insufficiency in 139 patients (90%), and stenosis plus insufficiency in 15 (10%). Carpentier-Edwards prostheses were implanted in 83 (54%), Ionescu-Shiley in 55 (35%), Hancock in 12 (8%), and Mitroflow in 4 (3%). Concomitant procedures were performed in 146 patients (95%). At least one previous operation had been performed in 86 patients (56%). Preoperatively, 139 patients were in functional Class III or IV (90%). Hospital death occurred in 20 patients (13%). Logistic regression analysis revealed that incremental risk factors for hospital death included increasing peripheral edema preoperatively (p = 0.04), and use of a Hancock prosthesis in the tricuspid position (p = 0.03). All 134 hospital survivors were followed at a mean of 66.01 months, range 1 to 162 months. There were 70 late deaths (52%). Log-rank test indicated that incremental risk factors for late death were: longer cross-clamp time at repair (p = 0.0007); higher pulmonary artery systolic pressure preoperatively (p = 0.01); earlier date of surgery (p = 0.03); and larger tricuspid prosthesis size (p = 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Events associated with rupture of intra-aortic balloon counterpulsation devices.

Nineteen intra-aortic balloon (IAB) ruptures occurred in sixteen patients during a three-year period. Perforation occurred secondary to abrasion with material failure or mishandling of the device during insertion. To avoid serious sequelae, it is important to be aware of the possibility of IAB rupture and to remove any defective device immediately upon recognition of an event.