A Comparative Study of Mechanical and Homograft Prostheses in the Pulmonary Position

Pulmonary valve replacement following repair of tetralogy of Fallot: comparison of outcomes between bio- and mechanical prostheses

OBJECTIVES

The aims of this study were to evaluate and compare the outcomes after pulmonary valve replacement (PVR) with a mechanical prosthesis (MP) and a bioprosthesis (BP).

METHODS

From 2004 through 2017, a total of 131 patients, who had already been repaired for tetralogy or Fallot or its variants, underwent their first PVR with an MP or a BP. Outcomes of interests were prosthesis failure (stenosis >3.5 m/s, regurgitation >mild or infective endocarditis) and reintervention.

RESULTS

The median age at PVR was 19 years. BP and MP were used in 88 (67.2%) and 43 (32.8%) patients, respectively. The median follow-up duration was 7.4 years, and the 10-year survival rate was 96.4%. Risk factors for prosthesis failure were smaller body surface area [hazard ratio (HR) 0.23 per 1 m2, P = 0.047] and smaller prosthesis size (HR 0.73 per 1 mm, P = 0.039). Risk factors for prosthesis reintervention were smaller body surface area (HR 0.11 per 1 m2, P = 0.011) and prosthesis size (HR 0.67 per 1 mm, P = 0.044). Probability of prosthesis failure and reintervention at 10 years were 24.6% (19.5% in BP vs 34.8% in MP, P = 0.34) and 7.8% (5.6% in BP vs 11.9% in MP, P = 0.079), respectively. Anticoagulation-related major thromboembolic events were observed in 4 patients receiving an MP.

CONCLUSIONS

MP might not be superior to BP in terms of prosthesis failure or reintervention. MP should be carefully considered for highly selected patients in the era of transcatheter PVR.

Porcine Versus Pericardial Pulmonary Valve Replacement in Adults With Prior Congenital Cardiac Surgery: Midterm Outcomes

Background:

Postcongenital heart surgery pulmonary regurgitation requires subsequent pulmonary valve replacement. We sought to compare the outcomes of pulmonary valve replacement after using bioprosthetic valves, porcine versus pericardial bioprosthesis.

Method:

Retrospective single-center study of consecutive pulmonary valve replacement in patients with pulmonary regurgitation following initial congenital cardiac surgery. From 2004 to 2016, 82 adult patients (53 males, 29 females) underwent pulmonary valve replacement at a mean age of 28.7 ± 8 years (range 18-52 years) with a mean time to pulmonary valve replacement of 24 ± 7 years (range 13-43 years). Porcine bioprosthetic valves (group 1, n = 32) and pericardial valves (group 2, n = 50) were used. Cardiac magnetic resonance imaging was performed (n = 54) at a mean of 18 ± 13 months before and 24 ± 21 months after pulmonary valve replacement.

Results:

No significant difference was seen between the groups except that the mean follow-up was longer for group 1 (5.02 ± 2.06 vs 4.08 ± 3.21 years). In-hospital mortality was 1.1%. Follow-up completeness was 100% with no late death. Mean right ventricular end-systolic and end-diastolic volumes reduced significantly in both the groups ( P < .001), whereas right ventricular ejection fraction remained unchanged (group 1, P = .129; group 2, P = .675) . Only the left ventricular end-diastolic volume increased in both the groups, but the increase was significant for group 2 only (group 1, P = .070; group 2, P = .015), whereas the left ventricular end-systolic and ejection fraction remained unchanged in both the groups. There was no reoperation for pulmonary valve replacement. Freedom from intervention was 93.8% (group 1) and 100% (group 2) at eight years after pulmonary valve replacement ( P = .407).

Conclusion:

Midterm outcomes of pulmonary valve replacement in our adult cohort were satisfactory. Both types of bioprosthetic valves performed comparably for eight years and were a good option in adults.

Mid-term outcomes of mechanical pulmonary valve replacement: a single-institutional experience of 396 patients

OBJECTIVES

Previous small-sized studies have demonstrated the safety and efficacy of mechanical pulmonary valve replacement (mPVR) in patients with congenital heart disease; however, the predictors of major complications and reoperation remained unclear.

METHODS

In a retrospective study, we reported the mid-term outcomes of a large-scaled series of patients, 396 patients, with congenital heart diseases who underwent mPVR in a single institution.

RESULTS

The patients' mean age at mPVR was 24.3 ± 9 years (4-58 years). Most patients (84.3%) underwent tetralogy of Fallot total correction. The median of follow-up was 36 months (24-49 months). Prosthetic valve malfunction caused by thrombosis or pannus formation developed in 12.1% of patients during follow-up period. Reoperation was performed in 7 cases with pannus formation and 6 cases with mechanical valve thrombosis. Freedom from reoperation at 1, 5, and 10 years was 99%, 97%, and 96%, respectively. Neither early nor mid-term mortalities were detected. Cox regression models showed that male gender and smaller valve size increased the risk of prosthetic valve failure. The age at mPVR, interval between congenital heart defect repair and mPVR, and concomitant procedures predicted reoperation. In multivariate analysis, younger age and the interval between first operation and mPVR predicted reoperation either.

CONCLUSIONS

The success rate of mPVR is excellent in mid-term follow-up. Younger age, longer interval between the repair of congenital defect and mPVR, and cooperation increased reoperation risk. However, strict adherence to life-long anticoagulation regimen and patient selection are of great importance for the implementation of mPVR.

Pulmonary Valve Replacement With a Bovine Pericardial Valve

Objectives:

From a population of 90 patients after pulmonary valve replacement with a biological valve (Carpentier-Edwards Perimount valve), 56 of 80 available patients were examined five years after surgery.

Background:

Pulmonary valve replacement is needed in many patients with congenital heart disease. Homografts have limited availability and predictable degeneration, and mechanical valves require anticoagulation. No superiority of one kind of pulmonary valve replacement has been shown. Biological valves that are readily available are being used and evaluated in increasing numbers.

Methods:

In this cross-sectional study, five years following surgery, data were gathered from hospital charts, echocardiography, stress echocardiography, magnetic resonance imaging, and exercise testing.

Results:

In 90 patients, there were three new valve replacements, one early cardiac death, and four late noncardiac deaths. Echocardiographic assessment of the study group showed pulmonary Doppler velocities (m/s) before, after operation, and at five-year follow-up of 2.8 ± 1.1, 1.6 ± 0.4, and 2.3 ± 0.7, respectively. The assessed insufficiencies (0-3) at the same times were 2.3 ± 1.0, 0.3 ± 0.4, and 1.1 ± 0.8. Maximal oxygen uptake increased from 65.6% ± 10.1% to 77.1% ± 18.2% of predicted and QRS width increased by 7 ± 23ms. Valve degeneration could be associated with young age but not with diagnosis or valve size.

Conclusion:

In our study, the biological valve in the pulmonary position showed excellent mid-term results with few reoperations, low gradients, and mild to moderate insufficiency. Oversizing, in contrast to young age, was not a risk factor for valve degeneration. In younger patients, this allows later percutaneous replacement, reducing the need for further surgery. However, longer follow-up is needed.

Mid-term outcome of mechanical pulmonary valve prostheses: the importance of anticoagulation

INTRODUCTION

Pulmonary valve replacement (PVR) is being performed more commonly late after the correction of tetralogy of Fallot. Most valves are replaced with an allograft or xenograft, although reoperations are a common theme. Mechanical prostheses have a less favorable reputation due to the necessity of lifelong anticoagulation therapy and higher risk of thrombosis, but they are also less likely to require reoperation. There is a paucity of data on the use of prosthetic valves in the pulmonary position. We report the midterm outcomes of 38 cases of PVR with mechanical prostheses.

METHODS

One hundred twenty two patients who underwent PVR were studied. Thirty-eight patients, mean age 25 ± 8.4 years underwent PVR with mechanical prostheses based on the right ventricular function and the preferences of the patients and physicians. Median age of prosthesis was 1 year (range 3 months to 5 years).

RESULTS

Seven (18%) patients had malfunctioning pulmonary prostheses and two patients underwent redo PVR. Mean International Normalized Ratio (INR) in these seven patients was 2.1±0.8. Fibrinolytic therapy was tried and five of them responded to it well. There was no significant association between the severity of right ventricular dysfunction, patient's age, prostheses valve size and age of the prosthesis in the patients with prosthesis malfunction.

CONCLUSION

PVR with mechanical prostheses can be performed with promising midterm outcomes. Thrombosis on mechanical pulmonary valve prostheses remains a serious complication, but most prosthesis malfunction respond to fibrinolytic therapy, underscoring the need for adequate anticoagulation therapy.

New technologies for surgery of the congenital cardiac defect

The surgical repair of complex congenital heart defects frequently requires additional tissue in various forms, such as patches, conduits, and valves. These devices often require replacement over a patient's lifetime because of degeneration, calcification, or lack of growth. The main new technologies in congenital cardiac surgery aim at, on the one hand, avoiding such reoperations and, on the other hand, improving long-term outcomes of devices used to repair or replace diseased structural malformations. These technologies are: 1) new patches: CorMatrix® patches made of decellularized porcine small intestinal submucosa extracellular matrix; 2) new devices: the Melody® valve (for percutaneous pulmonary valve implantation) and tissue-engineered valved conduits (either decellularized scaffolds or polymeric scaffolds); and 3) new emerging fields, such as antenatal corrective cardiac surgery or robotically assisted congenital cardiac surgical procedures. These new technologies for structural malformation surgery are still in their infancy but certainly present great promise for the future. But the translation of these emerging technologies to routine health care and public health policy will also largely depend on economic considerations, value judgments, and political factors.

Long term results of right ventricular outflow tract reconstruction with homografts

Background

Homograft cardiac valves and valved-conduits have been available in our institute since 1992. We sought to determine the long-term outcome after right ventricular outflow tract (RVOT) reconstruction using homografts, and risk factors for reoperation were analyzed.

Materials and Methods

We retrospectively reviewed 112 patients who had undergone repair using 116 homografts between 1992 and 2008. Median age and body weight at operation were 31.2 months and 12.2 kg, respectively. The diagnoses were pulmonary atresia or stenosis with ventricular septal defect (n=93), congenital aortic valve diseases (n=15), and truncus arteriosus (N=8). Mean follow-up duration was 79.2±14.8 months.

Results

There were 10 early and 4 late deaths. Overall survival rate was 89.6%, 88.7%, 86.1% at postoperative 1 year, 5 years and 10 years, respectively. Body weight at operation, cardiopulmonary bypass (CPB) time and aortic cross-clamping (ACC) time were identified as risk factors for death. Forty-three reoperations were performed in thirty-nine patients. Freedom from reoperation was 97.0%, 77.8%, 35.0% at postoperative 1 year, 5 years and 10 years respectively. Small-sized graft was identified as a risk factor for reoperation.

Conclusion

Although long-term survival after RVOT reconstruction with homografts was excellent, freedom from reoperation was unsatisfactory, especially in patients who had small grafts upon initial repair. Thus, alternative surgical strategies not using small grafts may need to be considered in this subset.