EComment. Unidirectional flap valve patch closure of ventricular septal defects

Abstract

Talwar and colleagues are to be congratulated on the excellent results they have obtained with this difficult group of patients [1]. Patients with pulmonary hypertension and elevated pulmonary vascular resistance represent a very significant proportion of children with congenital heart defects in developing, transitional and emerging countries around the world secondary to the large percentage of these populations with poor access to sophisticated medical care [2]. Labelling a patient as “inoperable” secondary to pulmonary hypertension and elevated pulmonary vascular resistance based upon questionable cardiac catheterization data is committing these children to inexorable decline in health and progression to Eisenmenger's physiology. The expense of electromagnetic cardiac output (ECMO) and the sophisticated medications that are required to combat post-operative pulmonary hypertension is simply beyond the budgetary scope of most hospitals in developing countries [3]. The fenestrated uni-directional flap valve ventricular septal defect (VSD) closure technique is a simple and inexpensive alternative. There is no absolute level of pulmonary vascular resistance for which the uni-directional flap valve technique should be used. The protection provided by the fenestration works whether an acute crisis develops or there is sustained pulmonary hypertension post-operatively. As such the technique provides an opportunity to extubate these patients early post-operatively, thus avoiding the potential complications associated with paralysis, sedation and relatively long intubation times. Moreover this approach is far more cost effective and in countries with restricted health care funds the benefits are self-evident. The long-term benefit of this technique is controversial. Gan et al. recently published a report stating that there was neither short term nor long term benefits using this technique [4]. Retrospectively analyzing two propensity matched groups, one with the uni-directional technique and the other using routine VSD closure, they found no difference in early or late mortality. Interestingly we found that for simple VSD closure using our modification resulted in a 3.6% (54/56) mortality rate [5], much below the 6.5% mortality rate they quoted for the routine closure VSD mortality rate in this propensity matched group. We were unable to show any difference in survival up to 8 years following surgery for those with a pre-operative pulmonary vascular resistance above 10 Wood units compared to those below 10. The world-wide availability of Sildenafil and relatively modest cost in most countries presents an opportunity for those patients with elevated pulmonary vascular resistance to receive potential life-altering procedures. The uni-directional flap valve VSD closure technique will provide these patients with a relatively low operative mortality rate and the use of Sildenafil for those who have persistent pulmonary hypertension a medical therapy to help lower pulmonary artery pressure. We have just completed a study of 36 consecutive double patch flap valve operations using Sildenafil in the post-operative period (unpublished data). Enrolment required a pulmonary artery pressure of greater than 50% systemic post-operatively. Hospital mortality was 2.8% (1/36), and following 3 months of therapy 78% (28/35) had normal pulmonary pressures by echo. The uni-directional flap valve VSD closure technique is beneficial and simplifies the post-operative management and decreases the operative mortality in this challenging group of patients.