[The conversion of a modified Fontan procedure to a total extracardiac cavo-pulmonary conduit. The Medico-Surgical Cardiology Group].

BACKGROUND

After a modified Fontan procedure with atriopulmonary or atrioventricular conduit, some patients present stress intolerance, supraventricular arrhythmia, recurrent pleuropericardial or ascitic effusions, and protein-losing enteropathy, all of which are signs that the previous procedure has failed. The aim of this study was to evaluate the midterm outcome after surgical therapy for this condition.

MATERIAL AND METHODS

Between August 1994 and December 1997, nine patients (6 males and 3 females), age 10 to 39 (mean 21.5) years, underwent conversion of previous modified Fontan procedure to total extracardiac cavo-pulmonary connection. Time from the previous procedure was 6 to 18 years (mean 10). Diagnosis was tricuspid atresia with pulmonary stenosis (n = 2), double-inlet left ventricle and concordant ventriculoarterial connection (n = 3), double-inlet left ventricle and discordant ventriculoarterial connection (n = 3), Holmes heart (n = 1). Nine patients presented decreased stress tolerance, seven had arrhythmia, five had pleuropericardial effusions and two had protein-losing enteropathy. In all but one patient, right atrial pressure was higher than 15 mmHg, while in six patients the cardiac index was less than 2 l/min/m2. A polytetrafluoroethylene non-valved conduit was interposed between the inferior vena cava and the right pulmonary artery for conversion in all patients. A bidirectional cavo-pulmonary anastomosis (modified Glenn) was associated in all patients. Evaluation was done by NYHA Class and by an arbitrary score assigned to patients based on 7 parameters.

RESULTS

There was no perioperative mortality. All patients were clinically improved at a mean follow-up of 24 months (range: 3 to 46). No patient had effusions, and the arrhythmias disappeared in 4 patients and were controlled by medical therapy in one. The two patients with protein-losing enteropathy improved markedly within 30 days and the score dropped below 10 points.

CONCLUSIONS

The conversion of the modified Fontan procedure to total extracardiac cavo-pulmonary connection improves clinical condition by decreasing the right atrium-pulmonary gradient and right atrial preload, and by providing a laminar cavo-pulmonary flow without any need for intracardiac anastomoses. This procedure should be undertaken early in this subset of patients, before ventricular failure ensues.