Long-term results after aortic valve replacement with four different prostheses

Midterm results of aortic valve replacement with cryopreserved homografts

OBJECTIVE

The aim of this study was to analyze the midterm clinical results of aortic valve replacement with cryopreserved homografts.

MATERIALS AND METHODS

Aortic valve replacement was performed in 40 patients with cryopreserved homograft. The indications were aortic valve endocarditis in 20 patients (50%), truncus arteriosus in 6 patients (15%), and re-stenosis or regurtitation after aortic valve reconstruction in 14 (35%) patients. The valve sizes ranged from 10 to 27mm. A full root replacement technique was used for homograft replacement in all patients.

RESULTS

The 30-day postoperative mortality rate was 12.5% (5 patients). There were four late deaths. Only one of them was related to cardiac events. Overall mortality was 22.5%. Thirty-three patients were followed up for 67±26 months. Two patients needed reoperation due to aortic aneurysm caused by endocarditis. The mean transvalvular gradient significantly decreased after valve replacement (p<0.003). The last follow up showed that the 27 (82%) patients had a normal left ventricular function.

CONCLUSION

Cryopreserved homografts are safe alternatives to mechanical valves that can be used when there are proper indications. Although it has a high perioperative mortality rate, cryopreserved homograft implantation is an alternative for valve replacement, particularly in younger patients and for complex surgical problems such as endocarditis that must be minimalized.

Thirty years experience with heart valve surgery: isolated aortic valve replacement

BACKGROUND

Thirty years have elapsed since the commencement of open-heart surgery in South Australia. A retrospective study was performed to evaluate mortality and complication rates and to identify factors associated with poor outcomes in all patients who underwent prosthetic aortic valve replacement during this period.

METHODS

Questionnaires and personal contact have been used to generate a combined database of pre-operative and post-operative information and long-term follow-up on 1322 patients who underwent isolated prosthetic aortic valve replacement at the Cardio-Thoracic Surgical Unit of the Royal Adelaide Hospital between 1963 and 1992.

RESULTS

Complete survival follow-up data were obtained for 94% (1241) of the patients. The Bjork-Shiley valve was used in 66% (875) of the patients, a Starr-Edwards prosthesis in 31% (412), a St Jude prosthesis in 2% (26), and only 0.7% (9) bioprosthetic valves were inserted. The hospital mortality rate for the 30-year period was 2.9%. Progressively older and less fit patients have undergone surgery in recent years. The long-term survival of patients with aortic stenosis and aortic incompetence was not significantly different. Long-term survival was significantly shorter for patients with higher New York Heart Association (NYHA) functional classifications, and for patients in pre-operative atrial fibrillation. Pre-operative dyspnoea was significantly improved following aortic valve replacement. The rates of postoperative haemorrhagic and embolic complications were low by comparison with other published series.

CONCLUSIONS

Aortic valve replacement can be performed with low hospital mortality and complication rates, and significant symptomatic improvement can be expected. Aortic valve recipients have a favourable prognostic outcome compared with an age- and sex-matched population, and risk factors that determine long-term survival can be identified pre-operatively.

Lunular hypertrophy and aortic valve disease

Cuspid malcoaptation secondary to abnormal hypertrophy in combination with stiffening involving the line of apposition (lunular hypertrophy) has not been recognized as a cause of aortic valve dysfunction. This entity was found in 50 adults (mean age, 62 years). Thirty-three had pure aortic valve insufficiency (> or = 3+, n = 13; < 3+, n = 20), 13 had mixed aortic valve insufficiency and stenosis (> or = 3+, n = 2; < 3+, n = 11), and 4 had pure aortic valve stenosis. Forty-one had a history of rheumatic heart disease and advanced mitral valve disease, and 7 had coronary artery disease. All underwent shaving of the hypertrophic protuberances, which in 26 patients constituted the entire aortic valve repair. In the remaining 24 patients, aortic valve repair included one or more additional procedures; there were 15 commissurotomies, 12 debridements of calcium deposits from the base of the cusps, and 5 cusp resuspensions. Concomitant mitral valve repair was performed in 26 patients, mitral valve replacement in 15, tricuspid valve repair in 11, coronary artery bypass grafting in 7, and repair of an ascending aortic aneurysm in 2. In 2 patients, the attempt to repair the aortic valve was unsuccessful, necessitating valve replacement. There were 5 operative deaths (10%), but none were related to aortic valve repair. Forty-three patients entered follow-up (mean, 56 +/- 57 months). Three patients (7%) suffered late recurrent aortic valve insufficiency (at 6, 48, and 72 months). The remaining 40 patients (93%) had trivial or no recurrent aortic valve dysfunction. The 6-year actuarial freedom from aortic valve-related problems was 92%.(ABSTRACT TRUNCATED AT 250 WORDS)

Repair of asymptomatic aortic valve disease during other cardiac surgery

Repair of asymptomatic aortic valve disease was performed in 12 patients (9 female, 3 male, mean age 57.5 years) undergoing other cardiac surgery. Stenosis was the predominant aortic valve lesion in 7 (group A) with a mean gradient of 33.4 mmHg and regurgitation of mean grade 1.4 was predominant in 5 (group B). Cusp debridement +/- commissurotomy was performed in 9; commissural resuspension in 6 and repair of cusp perforation in 2. Perioperative transoesophageal echocardiography was used to assess the adequacy of repair in 4 patients. Prospective precordial echocardiographic follow-up is complete (mean 4.3 months). In group A there has been a significant reduction is peak aortic pressure gradient (33.4 vs 22.1 mmHg, p less than 0.05) and in cusp thickness (2.25 to 1.64 mm, p less than 0.05). In group B the degree of incompetence has improved in 3 of the 5 patients. Three patients have worsened valve disease following repair; in all these there was mixed valve disease of rheumatic origin. Aortic valve repair of asymptomatic disease during other cardiac surgery is a feasible technique which does not accelerate the disease process in the short term. Long-term follow-up is in progress to assess the prognosis of this preventive intervention.

Surgical aortic valvuloplasty using the Cavitron Ultrasonic Surgical Aspirator: an invasive hemodynamic follow-up study

Valve repair and calcium debridement in patients with calcific aortic stenosis, using the Cavitron Ultrasonic Surgical Aspirator (CUSA), results in a reduction in the aortic valve gradient while potentially avoiding long-term problems inherent to prosthetic valves. Invasive followup data in these patients has not previously been reported. Ten patients in whom CUSA debridement was performed underwent cardiac catheterization prior to and 8.0 +/- 2.5 months following the procedure. Compared to baseline, the aortic valve area significantly increased from 0.75 +/- 0.2 to 1.1 +/- 0.3 cm2 (p = 0.009) and the mean gradient was significantly reduced from 54 +/- 21 to 27 +/- 21 mmHg (p = 0.02) at followup. No significant change was noted in cardiac output, ejection fraction, left ventricular end systolic or diastolic volumes or left ventricular end diastolic pressure. However, 6 patients were found to have at least one grade worsening of aortic regurgitation. The development of increased aortic insufficiency in many patients after CUSA aortic valve debridement will likely limit this procedure's clinical utility.

Hypertrophy of nodules of Arantius and aortic insufficiency: pathophysiology and repair

Aortic insufficiency (AI) due to fibrosis and thickening of the nodules of Arantius in the otherwise normal aortic valve was found in 11 adults (age range, 41 to 65 years) between 1976 and 1988. Nine had concomitant mitral stenosis; 2 had coronary artery disease. In 6 patients AI was graded 3+ or greater; in 5 it was less than 3+. Correction of AI and restoration of cuspid flexibility and apposition by shaving the hypertrophied nodules was accomplished in all, with postrepair AI graded as 1+ or less. There was one hospital death, a patient who had prior mitral operation. Mean follow-up was 68 +/- 56 months. Only 1 patient had late (6 years) recurrent serious (3+) AI. Nine continued to have 1+ or less AI, based on echocardiography or catheterization (n = 6) or on physical examination performed at a mean of 74 months. We conclude that thickening of the nodules of Arantius may cause AI. Long-term correction can be accomplished by sculpturing of the involved cusps.

Aortic valve repair for aortic stenosis in adults

The stenotic aortic valve was surgically repaired in 48 adults, 21 women and 27 men, aged 38 to 83 years. Five had congenital aortic stenosis (AS), with a mean aortic valve gradient and area of 58 +/- 23 mm Hg (standard deviation) and 0.54 +/- 0.13 cm2, respectively; 32 had senile AS with a mean aortic valve gradient and area of 43 +/- 20 mm Hg and 0.98 +/- 0.41 cm2; and 11 had rheumatic AS with a mean aortic valve gradient and area of 59 +/- 24 mm Hg and 0.47 +/- 0.15 cm2. Only 6 patients underwent isolated aortic valvoplasty, 11 underwent concomitant mitral valve procedure, and 34 underwent concomitant coronary revascularization. Repair consisted of decalcification in 33 patients and decalcification as well as commissurotomy in 15 patients. There were three hospital deaths, none related to the aortic valve. Only 2 patients (both rheumatic) did not improve clinically. During follow-up (mean, 64 +/- 41 months) aortic valve restenosis developed in 24% (10 patients, 3/5 congenital, 4/11 rheumatic, and 3/32 senile) at a mean of 64 +/- 28 months. Postoperative Doppler echocardiographic assessment of 21 patients with senile AS at 1.1 +/- 2.7 and 18.1 +/- 1.4 months showed significantly lower aortic valve gradient and improved area in comparison with preoperative values. At 36 +/- 2.7 months, aortic valve gradient and area were not significantly different than preoperative values, and at 58.5 +/- 2.6 months aortic valve gradient was 1.41 (p = 0.07) times the preoperative value. At 7 years, actuarial freedom from aortic valve-related symptoms of the patients with senile AS was 87%. We conclude that in select patients aortic valve repair results in excellent relief of AS. Late restenosis is expected and more likely to occur in the valves with congenital and rheumatic disease than in those with senile disease.

Clinical results and in vivo valve function after implantation of a Bicer valve prosthesis in the aortic position

Between December 1981 and June 1987, 71 patients underwent aortic valve replacement with a Bicer monostrut tilting disc prosthesis. Clinical results and in vivo function of the artificial valve were assessed. The average age of the 71 patients at the time of operation was 51.3 +/- 11.5 years. The hospital mortality rate was 2.8% (two patients) and there were no further deaths during a mean (+/- SD) follow-up period of 2.4 +/- 1.6 years (range 1 month to 5.5 years) after surgery. There was also no occurrence of thromboembolism or valve dysfunction. Function of the Bicer valve prosthesis was assessed in 17 patients: 5 with a 21 mm valve, 7 with a 23 mm valve and 5 with a 25 mm valve. Examination was performed on average 10.3 +/- 8.1 months after surgery. Valve function was examined at rest and during exercise performed with a bicycle ergometer. Pressure gradients at rest were low: 21 mm valve = 8 mm Hg, 23 mm valve = 3 mm Hg and 25 mm valve = 2 mm Hg; the gradients during exercise were 11, 8 and 8 mm Hg, respectively. The valves had the following effective orifice area at rest: 21 mm valve = 1.54 cm2, 23 mm valve = 4.20 cm2 and 25 mm valve = 3.76 cm2; during exercise, the respective areas were 1.57, 3.48 and 3.01 cm2. These valves are deemed to be sufficiently wide for effective valve function. Aortographic observation indicated mild regurgitation that was within reasonable limits and posed no problem.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative analysis of tilting disc and ball valve prosthesis in aortic position

In a retrospective analysis, comparison was made between the Cutter-Smeloff ball valve (n = 63) and the Lillehei-Kaster tilting disc valve (n = 256) in the aortic position. No significant intergroup difference was found as regards rate of thromboembolism (0.6/100 patient years for both valve types), endocarditis (0.2 for Cutter-Smeloff and 0.5 for Lillehei-Kaster/100 patient years) and paraprosthetic leak (0.9 and 0.5, respectively/100 patient years). The actuarial curve of cumulative survival was similar for both valves until 6 years postoperatively. Thereafter the outcome was less favourable for the patients with Cutter-Smeloff valve (actuarial survival 79 +/- 5% than for those with Lillehei-Kaster valve (91.2 +/- 2%). The reason for this, statistically significant, difference may be associated with the difference in valve profiles.

Replacement of aortic valve combined with myocardial revascularization: determinants of early and late risk for 500 patients, 1967-1981

Five hundred consecutive patients underwent aortic valve replacement and coronary revascularization in the years from 1967 to 1981, with 29 (5.9%) in-hospital deaths. Current operative mortality (1978-1981) is 3.4%. Univariate and multivariate analyses were used to identify determinants of early and late risk. Female sex, aortic insufficiency, and advanced age increased in-hospital mortality, whereas use of cardioplegia decreased it. At follow-up of 471 patients who survived hospitalization for 1 to 135 months (mean 41) after surgery, 96 late deaths were documented. Survival rates were 87%, 80%, and 55%, and event-free survival rates were 80%, 65%, and 39% at 2, 5, and 10 years after surgery, respectively. The late survival rate was unfavorably influenced by the presence of moderately or severely impaired left ventricular function and double-vessel coronary disease; the rate was enhanced for patients in age group from 50 to 59 years old and was not influenced by the method of myocardial protection. The event-free survival rate decreased with the presence of moderately or severely impaired left ventricular function and was enhanced for patients with New York Heart Association class I or II symptoms before surgery. Patients with bioprostheses who did not receive anticoagulants had higher survival and event-free survival rates than did either patients with bioprostheses who received anticoagulants or patients with mechanical valves, whether they received anticoagulants or not.