Progressive Pulmonary Artery Band Restriction Is Associated with Restrictive Right Ventricular Physiology After Staged Repair of Complete Atrioventricular Septal Defect

Background/Objectives: Pulmonary artery banding (PAB) is used in selected high-risk infants with complete atrioventricular septal defect (AVSD). We examined whether progressive functional band restriction was associated with postoperative restrictive right ventricular (RV) physiology after staged repair. Methods: This retrospective single-centre cohort included 53 patients who underwent definitive biventricular repair between October 2022 and November 2025 after previous PAB. Postoperative restrictive RV physiology was operationally defined by pulmonary arterial end-diastolic forward flow (EDFF) explicitly documented as present or absent in contemporaneous written postoperative echocardiography reports within 6 h of intensive care admission. Early post-banding and final pre-repair Doppler gradients were compared within patients. Logistic regression assessed associations with EDFF. The primary clinical outcome was a composite major adverse event (MAE), comprising 30-day or in-hospital mortality, postoperative extracorporeal membrane oxygenation, or unplanned cardiac reoperation. Results: EDFF-defined restrictive RV physiology was identified in 21 patients (39.6%) on the initial postoperative assessment. Pre-repair PAB gradient was higher in EDFF-positive than EDFF-negative patients (93 vs. 72 mmHg; p < 0.001). Median patient-level gradient increase was 45 vs. 29.5 mmHg (p < 0.001). EDFF-positive patients had higher rates of low cardiac output syndrome (71.4% vs. 21.9%) and extracorporeal membrane oxygenation (33.3% vs. 3.1%). MAE occurred in 33.3% versus 12.5% of patients, respectively, without a statistically significant between-group difference (p = 0.090). In the primary adjusted model, pre-repair gradient was associated with EDFF (adjusted odds ratio per 10 mmHg, 5.14; 95% confidence interval, 1.82–14.48; p = 0.002). The association for patient-level gradient increase persisted after adjustment for interstage duration and weight gain (adjusted odds ratio per 10 mmHg, 3.51; 95% confidence interval, 1.65–7.50; p = 0.001). Conclusions: Greater functional PAB restriction and longitudinal gradient increase were associated with early postoperative EDFF-defined restrictive RV physiology and greater early postoperative morbidity. Findings are exploratory and do not establish causality or a validated intervention threshold.