Trypsin-like enzymes during fertilization in the shrimp Rhynchocinetes typus

OBJECTIVE: To determine factors affecting postoperative pulmonary circulation in patients with major systemic-to-pulmonary collateral arteries. METHODS: A total of 48 patients underwent biventricular repair subsequent to unifocalization at ages in the range 1-34 years. The preparative procedures consisted of ligation of the collateral arteries in 6, plasty to the pulmonary arteries using no artificial materials in 12 and extensive reconstruction using heterologous pericardial tubes in 30. The number of the pulmonary vascular segments unifocalized was 9-18 (16 +/- 3). The amount of flow draining via residual minute systemic-to-pulmonary collaterals measured at the time of repair was 4-58% (24 +/- 16%) of the total perfusion by the cardiopulmonary bypass machine. RESULTS: This value was 40 +/- 16% in 5 patients dying in the short term after repair. The number of segments was nine or ten after unifocalization in 2 of these. Another 4 patients died in the longer term, 3 of these with CATCH 22 syndrome dying because of pulmonary hypertension. Postoperative catheterization demonstrated mean pulmonary arterial pressures in the range 8-40 (21 +/- 9) mmHg and pulmonary resistance in the range 1.7-10 (5.0 +/- 2.1) units/m2. Pulmonary resistance was correlated statistically to age at repair (r = 0.77), the number of pulmonary vascular segments (r = -0.41) and to percent collateral flow (r = 0.48). The use of a heterologous pericardial tube for unifocalization was also related probably to higher pulmonary resistance. CONCLUSION: It is essential to accomplish effective unifocalizations followed by earlier definitive repair so as to establish better pulmonary circulation.