Background; Severe pulmonary excess flow and marginal growth of the pulmonary artery often cause impairment of pulmonary circulation early after congenital cardiac surgery. The resultant elevated vascular resistance may lead to pulmonary hypertension (PH), which is a major cause of postoperative morbidity. Endothelin-1 (ET-1) plays a key role in this process and bosentan hydrate (BOS), an ET-1 dual receptor blocker, may therefore be a logical treatment for impaired pulmonary circulation. We review our initial experience with BOS treatment in ten pediatric patients.
Patients and Methods; Age distribution; neonate: 1, 1-3months: 3, 4-6months: 5, 6-12months: 1. Down syndrome: 5. Operation performed; AVSD repair: 3, VSD closure: 2, TAPVD repair: 1, PAPVD repair: 1, DORV repair: 1, Truncus repair: 1, bidirectional cavopulmonary shunt: 1. BOS was administered orally or through a nasogastric tube at a dose of 0.75 mg/kg twice a day.
Results; All patients were treated with oral sildenafil citrate (SIL) prior to BOS treatment. Three patients suffered from PH-related symptoms despite SIL treatment. After adding BOS, all patients were weaned from SIL uneventfully without the symptoms. BOS was discontinued shortly after hospital discharge, except for three patients who had persistent PH. Only one patient had a robust increase in liver transaminase, which was normalized after discontinuation of BOS. There were no other adverse events during BOS treatment.
Conclusions; Our early experience suggests that ET-1 blockade may be an effective alternative approach for impaired pulmonary circulation that are refractive to existing therapies in the early postoperative period after congenital cardiac surgery.