Impact of Transcatheter Pulmonary Artery Intervention Following Superior Cavopulmonary Connection on Pulmonary Artery Growth

Introduction: Balloon and stent angioplasty of the pulmonary arteries (PAs) are frequently performed following superior cavopulmonary connection (SCPC), not only to normalize the caliber of the affected PA but also in hopes of maximizing downstream growth over time. There are limited data on the impact on subsequent PA growth prior to total cavopulmonary connection (TCPC). Methods: A single-center, retrospective cohort study was performed on children who underwent transcatheter (TC) PA intervention following SCPC between January 1, 2010, and December 31, 2018. Growth of treated and contralateral PAs was measured at the lobar bifurcation (distal branch PA [DBPA]) and in the proximal lower lobe (lower lobe branch [LLB]) on serial angiograms. Growth rate was evaluated using a mixed-effect model clustered by individual patient with an interaction term for treated PA and time to evaluate for differential growth rates between treated and contralateral PAs. Results: Thirty-five patients underwent TC PA intervention following SCPC, at a median of 70 days (interquartile range: 19-297 days) postoperatively. Significant growth was seen at both DBPA and LLB for raw (0.8 mm/year, 95% CI: 0.6-1.0, P <.001 for both) and body surface area (BSA) adjusted measures (8.4mm/m²/year, 95% CI: 5.6-11.2, P <.001; 7.9 mm/m²/year, 95% CI: 5.5-10.2, P <.001). The growth rate of the treated vessel was not significantly different from that of the contralateral vessel at the DBPA or LLB positions for raw (P =.71,.70) or BSA-adjusted measurements (P =.86,.64). Conclusion: Transcatheter PA intervention was associated with normal distal PA growth rate relative to the untreated side.