Histomorphometric analysis of intrapulmonary vessels in patients undergoing bidirectional Glenn shunt and total cavopulmonary connection

ObjectivesThe purposes of this study were to elucidate the histomorphometry of the intrapulmonary arteries in patients undergoing univentricular type of repairs and to identify the histomorphometric characteristics, if any, that may predispose patients to postoperative Fontan failure.Patients and methodsOperatively resected wedges of lung tissue from 44 patients undergoing univentricular type of repairs (aged 17 months to 34 years; mean, 83.52 ± 75.90 months) was subjected to histomorphometric analysis.ResultsDespite pulmonary arterioplasty, a low Nakata index was associated with 9.61 (95% confidence interval: 1.01–91.5; P = .003) times increased risk of death after the operation. A statistically significant difference in the mean indexed diameter of the intra-acinar pulmonary arteries (P = .03) was observed between patients undergoing superior and total cavopulmonary connections. Overall, there were 8 (8.2%), 4 (9.1%), 13 (29.5%), and 29 (65.9%) instances of intrapulmonary arterial intimal lesions, thrombosis, smooth muscle extension, and interstitial fibrosis, respectively. Among patients undergoing total cavopulmonary connection, only low Nakata index was significantly associated with the presence of severe intimal lesions, abnormal smooth muscle extension, intra-acinar pulmonary arterial thrombus, and smaller intra-acinar pulmonary arteries.ConclusionsA low Nakata index is significantly associated with the presence of severe intimal lesions, thrombus, abnormal smooth muscle extension, a lower mean indexed area of the intrapulmonary arteries, and poor postoperative outcome. However, none of the histomorphometrically derived parameters could conclusively predict the outcome after univentricular repair