A Novel Perspective on Histopathology Provides Novel Insights into Surgical Effects in Pulmonary Atresia,Ventricular Septal Defect,and Major Aortopulmonary Collateral Arteries: A Case-Series Study

Background: Never had literatures characterized the relationship between the property of major aortopulmonary collateral arteries (MAPCAs) and outcomes of selective unifocalization of pulmonary atresia with ventricular septal defects and MAPCAs. Methods: This is a case-series study. Thirteen patients were included. Angiography-based assessment was conducted to determine whether collateral arteries should be unifocalized or treated with intraoperative ligature. Specimens were collected and stained by HE and ET+VG. Results: Twelve patients underwent one-stage unifocalization at a median age of 37 months (range: 6–228 months) and a median weight of 14.0 kg (range: 5.0–49.0 kg), which produced a favorable right ventricle to aortic systolic pressure ratio of no more than 0.5 except in one patient who died. Patients were divided into three groups: Group 1 (n = 6), had no native pulmonary arteries, and collateral arteries supplied all pulmonary blood; Group 2 (n = 6) presented dysplastic native pulmonary arteries on one or both sides, and in some lung lobes or segments, blood was supplied only by collateral arteries; Group 3 (n = 1) had well-developed left and right pulmonary arteries, and collateral arteries, and pulmonary arteries provided blood flow to the same segments. Pathological reports demonstrated two types of collateral arteries: Elastic arteries presented an arborization distribution similar to native pulmonary artery walls, while muscular arteries showed high resistance and distortion. We selectively unifocalized single-supply collateral arteries with morphologic features based on the arborization distribution. Conclusions: We found that there were two kinds of MAPCAs with different histology, and we performed selective UF for MAPCAs that might belong to the elastic artery. Selective unifocalization achieved a low right ventricle to aortic systolic pressure ratio and favorable surgical effects.