Orthotopic pulmonic valve replacement with a pulmonary homograft as an interposition graft

Pulmonary insufficiency: preparing the patient with ventricular dysfunction for surgery

Insufficiency of any of the four cardiac valves is a common cause of heart failure in children. Progression of ventricular dysfunction can be predictable, but requires thorough understanding of valvar disease. In valvar regurgitation, the heart has to cope with an increased volume of blood. The pathophysiological sequence is similar for both the right and the left heart. There is initially an increase in end-diastolic volume, followed by an increase in end-systolic volume, and at the end, a decrease in the shortening and ejection fractions. Different compensatory mechanisms and pathophysiologic adaptations develop to maintain the stroke volume for each type of valvar insufficiency, but heart failure eventually ensues. When symptoms of heart failure develop, irreversible ventricular dysfunction is often established, and outcome after surgery may ultimately be compromised. Discerning the optimal time for intervention, before irreversible ventricular dysfunction develops, is a key point in the management of regurgitant valvar heart disease.

Pulmonary regurgitation: not a benign lesion

Pulmonary regurgitation (PR) is a common complication after surgical or percutaneous relief of pulmonary stenosis and following repair of tetralogy of Fallot. Significant PR is usually well tolerated in childhood. However, in the long term, chronic PR has a detrimental effect on right ventricular (RV) function and exercise capacity and leads to an increased risk of arrhythmia and sudden cardiac death (SCD). Recent advances in non-invasive imaging and, in particular, wider availability of cardiovascular magnetic resonance (CMR), have improved the assessment of PR and RV function in these patients. This in turn has facilitated decision making on the optimal timing for elective pulmonary valve replacement (PVR), which should be performed before irreversible RV dysfunction ensues.

Twenty-year follow-up of the Hancock modified orifice porcine aortic valve

BACKGROUND

The entire experience with the Hancock modified orifice porcine bioprosthetic aortic valve from 1976 to 1996 at the Brigham and Women's Hospital has been reviewed. Eight hundred forty-three patients received this valve with a total follow-up of 61,114 months, and a mean follow-up of approximately 72.5 months. There were 490 men and 353 women, and the predominate lesion was aortic stenosis (636 of 843); 365 (43%) patients required a concomitant coronary artery bypass graft operation.

METHODS

Patients were followed prospectively in the Brigham Cardiac Valve Data Registry, and the data were analyzed by the SAS statistical package, using actuarial survival curves and incidence per patient-year of morbidity and mortality.

RESULTS

The overall operative mortality was 45 of 843 (5.3%) with 23 of 478 (4.8%) for isolated aortic valve replacement and 22 of 365 (6.0%) for aortic valve plus coronary artery bypass graft operation. The major morbidity of this valve was structural valve dysfunction, which was significantly related to the age of the patient in whom the valve was placed. Actuarial probability of freedom from structural valve degeneration at 5, 10, and 15 years overall was 99%+/-1%, 79%+/-3% and 57%+/-4%, at 15 years, respectively. In patients younger than 50 years, freedom from structural valve dysfunction was 16%+/-8%, whereas in the age group older than 70 years it was 87%+/-5% (p = 0.0005). Thromboembolism at 10 and 15 years was 81%+/-3% overall, 84%+/-2% in patients in normal sinus rhythm, and 57%+/-13% in patients with chronic atrial fibrillation.

CONCLUSIONS

The Hancock modified orifice aortic valve, despite its more complicated fabrication, has been a reliable porcine bioprosthetic valve and can be used reliably in patients older than 70 years because of its low structural valve degeneration rate, and protection from stroke and anticoagulant hemorrhage in those patients in sinus rhythm.