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The Sulzer Carbomedics prosthetic heart valve (CP) is a commonly used mechanical valve in clinical practice. In the present study, we used conventional and color Doppler echocardiography to assess the hemodynamics of normally functioning CP in the aortic (n = 73) and mitral (n = 127) positions. Our findings demonstrate no significant correlation of Doppler-measured peak and mean pressure gradients and effective orifice area with implanted valve size and actual orifice areas, measured directly by the manufacturer for CPs in both the mitral and aortic positions. However, it is still useful to measure effective orifice area by Doppler because a value in the normal or nonstenotic range points to an unobstructed prosthesis in the aortic or mitral position, in the absence of poor left ventricular ejection fraction. A value in the stenotic range could mean a normally functioning or obstructed prosthesis and, therefore, may need further investigation, such as assessment of valve leaflet motion by transthoracic or transesophageal echocardiography or fluoroscopy. Valve regurgitation as evaluated by color Doppler flow mapping was mild in practically all CPs in the aortic position, and in the majority of CPs in the mitral position.

Fifty-four consecutive patients underwent aortic valve replacement with a pulmonary autograft (Ross operation) over an 18-month period. It was inserted as an intra-aortic cylinder in 13 patients and as a total aortic root replacement in 41; unwrapped in 16, partially wrapped with autologous pericardium in 12 and completely wrapped with bovine pericardium in 13. There were two cardiac deaths, one death from mediastinitis, and two early reoperations to replace an incompetent autograft. Comparison of postoperative echocardiographic data showed a higher incidence of moderate and severe autograft incompetence in the intra-aortic cylinder group and also in the subset without previous operation which had a total root replacement without a complete wrap. Autograft function was best in the group which received a total root replacement with a complete wrap and in those with previous cardiac surgery who received an unwrapped autograft. This preliminary information with short follow up supports the use of complete wrapping of the autograft when it is used as a total root replacement particularly in older patients without previous cardiac surgery in whom future autograft growth is not desirable.

Cryopreserved aortic valve homografts have become an accepted aortic valve substitute, but long-term studies with echocardiographic assessment of valve function are largely unavailable. Between 1981 and January 1, 1991, a total of 178 patients aged 9 months to 80 years (median 46 years) underwent implantation of a cryopreserved aortic valve homograft. Serial two-dimensional Doppler echocardiographic studies were obtained in 149 patients. Overall survival was 91% at 1 year and 85% at 8 years. Survival of patients undergoing isolated primary infracoronary aortic valve replacement was 99% at 1 month and 94% at 8 years. Twelve patients underwent homograft explanation. Freedom from explantation for leaflet degeneration was 95% at 8 years. Freedom from presumed leaflet failure (valve degeneration at explantation or aortic insufficiency grade 3/4 or more without reoperation on echocardiography) was 94% at 5 years and 85% at 8 years. By multivariable analysis younger recipient age was the only risk factor identified for leaflet failure. Ninety-five percent of patients followed up for 4 or more years were in New York Heart Association class I or II.

A total of 200 aortic vale re-replacements were performed between Jan. 1, 1975, and July 1, 1979. The re-replacements (RRP) were an isolated procedure or combined with coronary artery bypass grafting or resection of ascending aortic aneurysm. Ten patients (5%) died in hospital, compared with 24 (2.9%) among 842 patients undergoing isolated or combined initial aortic valve replacement (AVR) (p = 0.12). The mode of death was cardiac failure in six of the 10 patients, hemorrhage in two (from accidents at repeat sternotomy), and neurologic deficits in two (each with innominate vein transection at repeat sternotomy repaired by ligation). There were seven (3.9%) hospital deaths among 181 first RRP (p for difference from initial AVR = 0.5), but three (15%) of 19 died after the second or third RRP (p = 0.001). By simple contingency table analysis, preoperative New York Heart Association (NYHA) Class IV increased the risk of hospital death after RRP (p = 0.002), as did prosthetic valve endocarditis (p = 0.0005) and the use of cold ischemic arrest (p = 0.03). Logistic multivariate analysis showed advanced NYHA functional class (p = 0.02), use of cold ischemic arrest (p = 0.09), and increased aortic cross-clamps time (p = 0.03) to be incremental risk factors. Recommendations for reducing hospital deaths in the event of RRP are (1) reoperate before severe hemodynamic deterioration occurs, (2) plan and conduct the operation to minimize accidents from repeat sternotomy and dissection, (3) keep aortic cross-clamp time as short as possible, and (4) employ cold cardioplegia.

During a two-year period (August, 1971, to July, 1973) 1 Starr-Edwards Model 2400 and 135 Starr-Edwards Model 2320 aortic prostheses were inserted without postoperative antiocagulant therapy. Seven of these valves (including the Model 2400 prosthesis) have been replaced because of substantial transvalvular gradients resulting from fibrous overgrowth of the valve orifice. Symptoms associated with aortic stenosis occurred an average of nine months after the initial operation. Six patients had severe anemia (packed cell volume less than 30%) and hemolysis (serum lactic dehydrogenase greater than 900 units). Gradients across the prostheses ranged from 66 to 105 mm Hg with a mean of 87 mm Hg. One valve was size 8A, 3 were 10A, and 1 was 12A. Fibrous ingrowth was not observed in an earlier group of 23 patients receiving the Model 2310 or Model 2320 prosthesis who were placed on long-term anticoagulant therapy. These findings, coupled with a 9% incidence of thromboembolism at one year, indicate that patients having these prostheses inserted should receive long-term anticoagulant therapy.

We evaluated 643 patients surviving aortic, mitral, and aortic and mitral ("double") valve replacement with the Björk-Shiley prosthesis from 1 to 72 months (median 38 months) postoperatively. Intermediate-term survival rate was similar to that reported for other prosthetic and bioprosthetic devices. Factors unrelated to the device, but related to preoperative patient characteristics or intraoperative or early postoperative events, had important association with late survival rate. These included previous valve replacement, concomitant ventricular aneurysm resection, black race, preoperative functional class, method of myocardial protection, duration of ischemic arrest, ventricular arrhythmias, and double valve replacement. Concomitant coronary artery bypass grafting and the type of valve lesion had no effect on survival prognosis. Freedom from thromboembolism was equal to or superior to other devices, but valve thrombosis occurred 16 times in 15 patients and caused 13 deaths. Improvement in New York Heart Association (NYHA) functional class occurred in the majority of patients. We conclude that the Björk-Shiley valve is durable and effective, but, as with other devices, is associated with problems of thromboembolism and thrombosis. Intermediate-term survival is related also to non-device, patient-associated characteristics.

We reviewed our entire experience with composite graft replacement of the ascending aorta and aortic valve during a 63 month interval ending in December, 1979. Anuloaortic ectasia was the most common indication for operation, followed by aortic dissection (acute and chronic). Hospital mortality was 5% and was related to the preoperative functional status and the duration of intraoperative myocardial ischemia. Reoperation on the ascending aorta for reasons other than postoperative hemorrhage was required in five of the 82 hospital survivors (6%). By actuarial analysis, 90% of hospital survivors were free of any reoperation on the ascending aorta or aortic valve three years postoperatively, and 93% were free of reoperation related specifically to the composite graft. Pseudoaneurysms at the coronary ostia or distal aortic anastomosis were observed in five of 16 patients having postoperative angiography. One of the five patients has required reoperation. Follow-up has averaged 23.5 months (range: 0.2-60 months). Three year actuarial survival for the 86 patients was 81%, for 44 patients with anuloaortic ectasia was 88%, and for 31 patients with aortic dissection was 83%. Composite graft replacement of the ascending aorta and aortic valve is a satisfactory alternative to supracoronary graft replacement and aortic valve replacement. It offers the advantage of excluding all aneurysmal tissue from the aortic anulus to the innominate artery, thereby eliminating the potential for later development of aneurysms of the sinuses of Valsalva, a known complication of the supracoronary technique. It is the method of choice for patients with anuloaortic ectasia and cephalad displacement of the coronary ostia. It is suitable for many patients with acute or chronic dissection and for patients with sinuses of Valsalva aneurysms following previous operations on the ascending aorta or aortic valve.

Aortic valve endocarditis with an aortic root abscess cavity was treated by a modification of the standard technique of aortic homograft implantation in 3 patients. At a mean follow-up of 35 months, all 3 patients were well without reoperation or signs of aortic incompetence. This technique may, in some cases, be an alternative to the more complex procedure of homograft aortic root replacement with coronary reimplantation.

This article presents the University of Alabama experience with homograft aortic valve replacement for prosthetic valve endocarditis. Of 117 patients who have undergone homograft aortic valve replacement since 1981, there has been a total of 22 patients who underwent operation for endocarditis. Sixteen were isolated valve replacements, three combined with other procedures, and three were aortic root replacements. When placed in a setting of active endocarditis, there have been no reoperations for endocarditis of the homograft valve. Surgical techniques are presented for the freehand sewn homograft as well as aortic root replacement. Prosthetic valve endocarditis is a highly lethal event and when aortic valve replacement is advised in this setting, we believe a homograft aortic valve should be implanted whenever possible.

Actuarial freedom from reoperation for obstruction in 147 patients receiving cryopreserved or fresh allograft valved conduits between a ventricle and the pulmonary arteries was 94% at 3.5 years. The 2 patients undergoing reoperation were 6 and 36 months of age at the time of insertion of the allograft. Among 24 patients in whom cardiac catheterization was performed on indication late postoperatively, 5 had gradients of more than 40 mm Hg across the conduit. For comparison, among 78 patients receiving xenograft or irradiated allograft valved conduits, the percentages of freedom from conduit reoperation at 3.5, 5, 10, and 15 years were 99%, 95%, 59%, and 11%, respectively. The diameters of the allograft and xenograft valves inserted varied directly with the age and size of the patients, but in patients 3 to 5 years of age, allografts with a diameter of at least 21 mm could usually be used.

From November, 1973, through June, 1978, 428 operations in 425 patients were performed for replacement of aortic, mitral, or aortic plus mitral valves, utilizing 277 Hancock and 180 Carpentier-Edwards bioprostheses. Actuarially determined survival at 36 months was similar for all three groups and compared favorably with our experience with the Björk-Shiley prosthesis. Certain patient-related variables influencing late survival were identified by multivariate analysis and included previous operation for congenital heart disease, coronary artery bypass grafting in nonaortic valve replacement, race (black), age at operation, and New York Heart Association Functional Class. A small but definite incidence of thromboembolism occurred in all three groups, again similar to our experience with the Björk-Shiley prosthesis. Multivariate analysis identified four factors influencing risk of thromboembolism: previous cardiac operation, age, double-valve replacement, and rhythm at discharge. Valve degeneraation occurred, primarily in children and young adults. Over the medium term, the porcine bioprosthesis compared favorably with mechanical prostheses in terms of survival, function, and thromboembolism. Certain patient-related variables affecting survival may be modified by earlier surgical intervention.