Impact of placing a conduit from the right ventricle to the pulmonary arteries as the first stage of further palliation in the Norwood sequence for hypoplasia of the left heart

Abstract

Objective: We describe the experience from a single institution with the Norwood sequence of palliation for hypoplasia of the left heart, emphasizing complications related to placement of a conduit from the right ventricle to the pulmonary arteries and their management.

Methods: Between November, 2002 and January, 2006, we palliated 32 patients with hypoplastic left heart syndrome or its variants by placing a conduit from the right ventricle to the pulmonary arteries. We reviewed retrospectively the charts and angiograms from these patients.

Results: Hospital survival after construction of the conduit was 90.6%. There were 3 interstage deaths, of which 2 were likely due severe obstruction of the conduit. Stents were implanted into the proximal or medial portions of the conduits of 3 patients. Early revision of the distal anastomosis, and shortening the conduit, was performed early postoperatively in 2 patients. So far, 24 out 26 survivors of the first stage underwent a bi-directional cavopulmonary anastomosis after a mean interval of 4.3 plus or minus 1.4 months. Of these, 3 required a semi-urgent second stage of palliation because of worsening cyanosis, with one patient dying after the second stage. Completion of the Fontan circulation by insertion of an extracardiac conduit was performed in 8 patients at the mean age of 19.8 plus or minus 2.2 months. We were able to achieve biventricular repair in 1 patient, with aortic atresia, hypoplastic arch and ventricular septal defect, 4.3 months after the initial palliative procedure. Overall survival of the whole cohort of 32 patients was 78.9%, plus or minus 7.8%, at 5 months, and 74.3%, plus or minus 8.6%, up to 25 months.

Conclusions: The introduction of the conduit placed from the right ventricle to the pulmonary arteries has led to an improved outcome in the complex entity of hypoplastic left heart syndrome and its variants. Stenosis of the conduit, nonetheless, may account for significant interstage morbidity, and often requires intervention or early installation of the second stage of palliation.