Ventricular outflow tracts after Kawashima intraventricular rerouting for double outlet right ventricle with subpulmonary ventricular septal defect

Objective: To determine whether or not the ventricular outflow tracts can b e efficiently constructed in patients with double outlet right ventricle wi th subpulmonary ventricular septal defect by the Kawashima intraventricular rerouting in which the morphologically right ventricular outlet is divided into two, one for the systemic and the other for the pulmonary circulation s. Methods: The intraventricular rerouting procedure was carried out in nin e patients with this particular malformation. Age at repair ranged from 35 days to 3 years old. The distance between the attachments of the tricuspid and the pulmonary valves was 10 mm or greater in all except one patient in whom the measured value was 3 mm. Resecting subaortic musculature appropria tely, a tailored patch, either oval-shaped tin seven) or heart-shaped tin t wo), was placed to construct an unobstructed channel for the left ventricul ar outflow tract with its diameter greater than that of the anticipated nor mal aortic orifice at the time of repair. For an unobstructed channel to th e pulmonary arteries, enlargement of the right ventricular outflow tract wa s carried out using a patch in six. Results: All patients survived the oper ative procedure. On postoperative catheterization, mean pulmonary arterial pressure was 15 +/- 8 mmHg, and cardiac index was calculated as 3.3 +/- 0.6 l/min per m(2). It proved that the constructed left ventricular outflow tr act can become larger in the longer term. Pressure gradient across the left ventricular outflow tract was greater than 20 mmHg in two patients in the intermediate term. One of these two underwent reoperation for the obstructi on 10 years after the initial repair. It was suspected that use of a heart- shaped internal conduit, which seems to result from inadequate conal resect ion, was one of the possible causes of such obstruction in the longer term. Pressure gradient of 47 mmHg was seen across the right ventricular outflow tract in one patient, although this patient has undergone no reoperation. Enlargement of the right ventricular outflow tract could minimize postopera tive obstruction for the pulmonary pathway. Conclusions: The intraventricul ar rerouting remains one of the attractive surgical options for repair in t his particular setting, in terms of successful construction of the ventricu lar outflow tracts. (C) 1999 Elsevier Science B.V. All rights reserved.