Aortic Valve Replacement with Starr-Edwards Valves over 14 Years

Three hundred thirteen patients underwent aortic valve replacement with 319 Starr-Edwards caged-ball prostheses and have been followed for 1 to 14 years. Hospital mortality (24.8%) and first-year mortality (4.8%) suggest that this is a high-risk group. Overall postoperative patient survival was 37.1%, with 18.8% free from any event, at 14 years. Thromboembolism was the most significant single event (a probability of 18.7% at 14 years), and the Series 2300/2320 valves were associated with a probability of hemolysis of nearly 80% over 13 years.Patients who underwent valve replacement before 1973 had a significantly greater probability of late death (31.1%) and of complications (47.1%) during the first 5 years. Those patients undergoing replacement after 1973 had a significantly greater probability of thromboembolic episodes (15.4%).Starr-Edwards caged-ball prostheses provide an acceptable valve replacement for high-risk patients. However, the overall complication rate of 81.2% over 14 years, compared with 78% for homograft valves for the same period, does not support the adoption of this prosthesis as the valve of first choice at this hospital.     

Long-term assessment of aortic valve replacement with autologous pulmonary valve

Two hundred two autologous pulmonary valves were transplanted into the aortic position between 1967 and 1982 at the National Heart Hospital in London. The indication for operation was congenital or acquired aortic valve disease, and the patients were followed for periods from 1 to 4 years. The patients were not anti-coagulated, but the entire series has been completely free from thromboembolism or bleeding. The actuarial prediction of freedom from valve-related deaths was 82 +/- 6% at the end of the fourteenth year after operation; deaths were due to reoperations for technical failure and to infective endocarditis. Event-free survival of the autologous pulmonary valve in the aortic position was 73 +/- 6% after 14 years at risk. Valve failure resulted mainly from technical problems encountered during the early years of surgical experience. There was no macroscopic or histological evidence of calcification in any of the failed valves. The right ventricular outflow was reconstructed with an aortic homograft in the majority of patients; 81 +/- 5% of these homografts demonstrated event-free performance over a 12-year follow-up period. It is concluded that the long-term performance of a pulmonary autograft inserted for aortic valve disease is superior to that of any other valve substitute and that the operation offers an almost ideal means of aortic valve replacement in appropriate patients.     

The Marfan Syndrome: Surgical Technique and Follow-up in 50 Patients

Fifty patients with Marfan's syndrome underwent operation at the National Heart Hospital because of cardiovascular complications. Forty-six had an aneurysm of the ascending aorta, 13 had chronic dissection, and 6 had acute dissection of the aortic wall. Forty-three aortic valves were incompetent, and five were stenotic and incompetent. One mitral valve had minor regurgitation. The Starr-Edwards prosthesis was used in 36 patients, homograft valves in 4, fascia lata valves in 2, and xenograft valves in 6. The ascending aorta was replaced with a Dacron tube in 40 patients and with an aortic homograft in 2. Three patients required Dacron patches over the aneurysm, and 1 patient had plication of the aortic wall.Early mortality totaled 12% (6 patients). Only 1 of these patients died in the last five years. Reoperations for homograft incompetence, periprosthetic leak, and acute dissection of an unreplaced aorta resulted in 1 hospital death (33%). Forty-three patients have been followed for up to 8.5 years (mean, 3.5 years), with 7 late deaths (16.2%). The improvement in recent surgical results with decreased operative mortality supports an aggressive surgical approach to Marfan's syndrome in view of the poor prognosis for the natural history of this disease.     

Assessment and Comparison of the Performance of Cardiac Valves

A statistical method is presented to assess and compare cardiac valve performances. Patient survival and valve performances have been separated, and valve function and malfunction have been described in comprehensive and comparable terms. Formulas are proposed to calculate the significance of the difference between two survival probabilities as well as to calculate the instantaneous rate of events and the median remaining lifetime.     

Clinical Durability of the Pericardial Xenograft Valve: Ten Years' Experience with Mitral Replacement

Data from 366 patients with mitral valve replacement (250 single and 116 multiple) who received pericardial xenografts between 1971 and 1981 were analyzed. Cumulative duration of follow-up was 1,151 patient-years, with a maximum duration of 10.7 years. Actuarial survival at 11 years is 71.6 ± 14.2%. Pericardial valve failure occurred in 7 patients (0.6 episodes per 100 patient-years). Actuarial freedom from valve failure at 11 years is 90.4 ± 9.1% for the entire series. Although 275 (75.1%) patients were in chronic atrial fibrillation, anticoagulants were not used in any patient beyond the first 6 postoperative weeks. The incidence of emboli was 0.6% per year. Six episodes occurred following single mitral valve replacement and 1 after multiple valve replacement (5 early and 2 late). The actuarial freedom from embolism is 96.4 ± 1.5% at 6 and 11 years postoperatively. Valve thrombosis has not been encountered.This analysis has shown a low incidence of valve dysfunction and a very low risk of embolic complications without long-term anticoagulation. The pericardial xenograft is a safe substitute for the mitral valve, with predictable behavior during the first decade of follow-up.     

Thirteen Years' Experience with the Kay-Shiley Disc Valve for Tricuspid Replacement in Ebstein's Anomaly

From August, 1965, to November, 1974, 11 patients underwent operation for Ebstein's anomaly. In 1 patient operated on on August 16, 1965, the early Kay-Shiley disc valve was used. In the remaining 10 patients, the Kay-Shiley muscle guard valve was inserted. This valve was designed to prevent the prosthesis from encroaching on the right ventricle, thereby increasing the flow around the disc. One patient with a history of Wolff-Parkinson-White syndrome died of dysrhythmia on the first postoperative day. The other 10 patients have been followed from 4 to 13 years (mean, 6 years 2 months) after operation. Seven patients are working full-time without difficulty, 2 are housewives, and 1 attends school. All patients have improved at least one class in the New York Heart Association Functional Classification.     

Triple-Valve Replacement: An Analysis of Eight Years' Experience

The total experience with combined aortic, mitral, and tricuspid valve replacement in 38 patients during an eight-year period ending in December, 1974, is reviewed. The hospital mortality was 23.7% (9 patients) and was influenced by the preoperative New York Heart Association Functional Class: 18% (5 of 28 patients) in Class III and 40% (4 of 10) in Class IV. Intraoperative myocardial injury was the other important factor affecting hospital mortality. The majority of late deaths were related to cardiac causes. The five-year survival was 53% (20 patients) for the entire group and 62% (17 patients) for the Class III patients. At latest follow-up (mean, 44 months), 22 (76%) of the hospital survivors had improved by at least one functional class. It appears that surgical intervention before patients reach Class IV status should give better early and long-term results. Our current indications for tricuspid valve replacement as opposed to repair are presented.     

Transcervical Thymectomy with the Aid of Mediastinoscopy for Myasthenia Gravis: Eight Years' Experience

Fifty-eight patients with myasthenia gravis, including 12 children, underwent thymectomy. Eleven of them (19%) had total stable remission and 42 (72%) showed clinical improvement and were able to reduce their anticholinesterase medication. These two groups combined comprised 53 patients (91%). There was no operative or postoperative mortality.Histopathological examination of the resected thymuses revealed a tumor (benign thymoma) in 4 patients (7%), thymitis in 36 (62%), and no pathological changes in 18 (31%). Patients with few or no germinal centers tended to achieve remission more rapidly than those with numerous germinal centers.     

Acceptable Size of the Pulmonary Valve Ring in Congenital Cardiac Defects

Because congenital defects are being corrected at progressively younger ages, knowledge of the normal sizes of cardiac orifices and their acceptable limits is becoming increasingly important.A graphically corrected table of normal children's heights and pulmonary artery diameters is given. In addition, reasons are presented for the belief that a decrease in the cross-sectional area of up to 50% of normal may be considered acceptable during corrective procedures; in light of present knowledge any further decrease in cross-sectional area, in particular below 25% of normal, should probably not be left uncorrected.     

Right ventricular aberrant muscle bundle. Review of reported cases and recent case report

A patient with right ventricular aberrant muscle bundle is described, and other reported patients with the same anomaly are reviewed. In our patient a large pressure gradient developed across the bundle during the course of a ten-year follow-up. Operation successfully relieved the pressure gradient and symptoms.     

The Intraaortic Balloon Pump: An Analysis of Five Years' Experience

During a five-year period, 178 patients had the intraaortic balloon pump (IABP) inserted for circulatory support. The IABP was used most frequently as an adjunct for weaning patients from cardiopulmonary bypass. Seventy-seven of 103 patients (75%) were successfully weaned from cardiopulmonary bypass with the IABP, and 36 of them (35%) ultimately survived hospitalization. Other indications for the IABP included circulatory support before cardiac operation (16 patients), operative prophylaxis in high-risk patients (13), and postoperative hemodynamic support (23). Additionally, the IABP was placed in 23 patients who did not undergo cardiac operation.The incidence of IABP-related complications was significantly less when the IABP was inserted through the ascending aorta (4%) intraoperatively compared with the femoral or iliac artery (25%) (p < 0.05). This was due primarily to vascular complications and groin wound infections that occurred with the femoral or iliac artery approach. IABP-related spinal cord paralysis developed in 3 patients (1.7%).We conclude that the IABP is an effective support device for treating patients with left ventricular failure particularly when weaning them from cardiopulmonary bypass. However, the risk of complications, including paraplegia, must be carefully weighed when use of the IABP is considered, especially in situations in which its efficacy is less clear.     

Long-Term Sequential Hemodynamic Evaluation of Right Ventricular Outflow Tract Reconstruction Using a Valve Mechanism

From May, 1972, to May, 1978, right ventricular outflow tract reconstruction was performed in 20 patients with congenital heart disease. A monocusp patch constructed entirely of glutaraldehyde-stabilized calf pericardium, was employed in 19 patients, and a composite conduit consisting of a three-cusp pericardial xenograft valve in a Dacron tube was used in 1 patient.There were 2 hospital deaths (10%) and no late deaths. The follow-up ranged from 5 to 75 months (mean, 55.7 ± 4.6 months; total, 1,002 patient months). Eleven patients had completed 5 years of follow-up at the time of writing.Hemodynamic studies were performed in 10 patients at an average of 40 months after operation and the right ventricle-pulmonary artery systolic gradient was 9.3 ± 1.7 mm Hg. This was not significantly different in 6 patients who had a second postoperative catheterization at 51.8 ± 2.0 months following operation. Angiography showed fully mobile, thin valve cusps.These results compare well with those reported with other types of conduits, particularly with reference to relief of obstruction.     

The Performance of the Braunwald-Cutter Aortic Prosthetic Valve

Four hundred seventy-five patients underwent aortic valve replacement with the Braunwald-Cutter ball-valve prosthesis at two institutions. The early (30-day) hospital mortality was 4.7% for those with isolated aortic valve replacement and 6.9% for the entire group. For the former, 5-year actuarial survival of the hospital survivors was 72 ± 5.7%; for the latter group it was 71 ± 4.4%. Eleven patients (5 since the date of follow-up inquiry) have Suffered poppet escape, 9 of whom died. The actuarial incidence of known poppet escape is 4 ± 2.6% at 47 months; when the 5 patients suffering poppet escape since the date of follow-up inquiry are included, with certain assumptions, the incidence is 3.7 ± 1.14%. The projected probability of poppet escape using all 11 patients is 12.2% at 5 years; the 70% confidence bands of projected probability of poppet escape separate from those of the risk of rereplacement at 61 months. This and other analyses indicate that in general, patients with the Braunwald-Cutter aortic prosthesis should have it replaced 4 1/2 to 5 years after its insertion.     

A monitor for the continuous assessment of left ventricular performance after open-heart operations.

A cardiac monitoring system has been developed that incorporated phasic aortic blood flow measurement by an extractable electromagnetic flow probe and high-fidelity arterial blood pressure recordings. Cardiac output, stroke volume, and peak aortic blood flow are measured continuously; using logarithmic amplifiers, the pressure-flow derivatives of left ventricular function, such as cardiac power and stroke work, are obtained beat by beat. This monitor is used to follow the postoperative course of patients undergoing cardiac operations and to evaluate the hemodynamic effect of therapeutic agents.     

Fifty-two Consecutive Aortic Valve Replacements Employing Local Deep Hypothermia

From August, 1972, to May, 1974, 52 consecutive aortic valves were replaced with the Björk-Shiley tilting-disc prosthesis. The hospital mortality was zero. Patients ranged in age from 14 to 77 years, and 19 patients had simultaneous correction of associated cardiac lesions. Using techniques of low flow and local deep hypothermia, aortic valve replacement can be accomplished with little risk even in patients with associated coronary arteriosclerosis. Coronary artery perfusion is unnecessary and often hazardous. Follow-up periods vary from one to twenty-one months. Forty-nine patients are alive and substantially improved.     

The management of empyema thoracis by thoracoscopy and irrigation

A technique of irrigation for the management of empyema is described. Initial thoracoscopy under general anesthesia enabled full debridement and division of loculi within the empyema cavity under direct vision. Irrigation with two tubes was instituted until three consecutive cultures of irrigation fluid became sterile; then the chest drains were removed. The results in 12 patients are presented. Using this method, irrigation was required for an average of 14 days and chest drains were removed after an average of 20 days. Patients remained in the hospital for an average of 4.8 weeks. Tuberculous empyema was not found to be a contraindication to the irrigation technique.     

Comparison of Patients with Coronary Artery or Valve Disease: Intraoperative Differences in Blood Volume and Observations of Vasomotor Response

A review of 296 patients undergoing cardiac operations has shown that those with coronary artery disease have a blood volume deficit. The 148 patients with valve disease had a normal blood volume of 78 ml/kg (normal range, 68–88 ml/kg), while the 148 with coronary artery disease had a blood volume of 69 ml/kg (p < 0.001). Infusion of plasma prior to cardiopulmonary bypass as well as the total transfusion required afterward to maintain blood pressure indicated an important clinical difference in these two groups. Another finding was that the requirement for a drug to control blood pressure prior to use of cardiopulmonary bypass was greater in the coronary patients (p < 0.01). Comparison of the requirement for a hypotensive agent before and after bypass showed a greater predictability in the valve group. This experience leads us to conclude that patients with coronary artery disease and angina not only have a low blood volume, but they also have a marked vasoactive lability which shows up in their hemodynamic response to the conduct of an operation and to anesthesia.     

Spontaneous Heterograft Aortic Valve Failure

Glutaraldehyde-treated porcine aortic valve prostheses have been in clinical use for ten years. The long-term durability of these valves remains unknown although they have functioned well in most large clinical series for more than five years. At the present time, several manufacturers produce bioprostheses mounted on flexible stents. This report concerns the failure of an Edwards porcine xenograft in the aortic position 15 months following implantation. At reoperation, the right and left coronary leaflets of the explanted valve were torn from the aortic wall. The loss of wall integrity suggests that during the process of mounting the xenograft on the flexible stent, the aortic walls of the bioprosthesis may have been thinned beyond a critical point of maintenance of wall strength. The pathological and clinical findings of similar cases are reviewed.     

Prevention of “Strut-Snagging” during Mitral Valve Replacement with Stented Tissue Valves

A technique is described for preventing snagging of the struts during replacement of the mitral valve by stent-supported bioprostheses. The method is simple and is particularly applicable when the mitral valve annulus or the left atrium is small.     

The Effects of Sterilization and Storage Treatments on the Stress-Strain Behavior of Aortic Valve Leaflets

An investigation was made of the feasibility of using tensile tests to detect alterations in the molecular structure of aortic valve tissue brought about by sterilizing or storage treatments. Stressstrain tests were carried out on fresh valve leaflets from pigs and repeated with the same specimens after specified sterilization or storage treatments. It was found that the stress at a given strain was increased by treatment with ethylene oxide, buffered formalin, and tissue culture solution and decreased by treatment with antibiotics. The least change was with tissue culture solution and antibiotics.It has been suggested that the best method of allograft sterilization should involve minimal structural alteration to the collagen and elastic components of the tissue. Thus, treatment with tissue culture solution and antibiotics seems appropriate.