Abstract 11416: The “Natural History” of Intra-operative Pulmonary Artery Stents: A 20-year Perspective

Abstract

Background: Branch pulmonary artery (PA) stenoses are typically treated with catheter-based percutaneous therapies or surgical arterioplasty. Intra-operative (intra-op) PA stent placement is an alternative strategy. In this study, we sought to describe our 20-year experience with intra-op PA stent placement and to evaluate long-term patient outcomes, specifically the need and risk factors for re-intervention. Methods: We performed a retrospective review of all intra-op PA stents placed at our institution from 1994-2013. Patient and stent characteristics and outcome data were collected. Risk factors associated with re-intervention were identified using univariate cox regression analysis. Results: Eighty-one PA stents were placed in 68 patients, mostly to treat proximal PA stenoses (85%). Stent implantation was acutely successful in 67 patients (98.5%) with a procedural complication rate of 4.4%. Stents capable of being dilated to large diameters (“adult-size”) were used in 97% of patients. At hospital discharge, 93% of patients had no or mild residual PA stenosis by echocardiogram. During a median follow-up period of 6 years (interquartile range 0.9-12.7), 31 patients (46%) underwent PA re-intervention with a median time to first re-intervention of 2.5 years. Risk factors for re-intervention included age < 18 months (Hazard ratio [HR] 3.26, p=0.002) and body surface area < 0.47 m2 (HR 3.47, p=0.001) at the time of stent implantation, and the presence of multiple aorto-pulmonary collaterals in patients with tetralogy of Fallot (HR 3.19, p=0.02). Conclusions: Intra-op PA stent implantation is technically feasible with low procedural complications. It offers several advantages over transcatheter stenting, including the ability to implant adult-size stents in small patients while avoiding injury to percutaneous vessels, to position and flare stents to facilitate future percutaneous stent re-dilation, and to access the PAs directly, which shortens procedural time and eliminates radiation exposure. It also may prevent re-stenosis from scar tissue caused by patch arterioplasty. A future direct comparison of intra-op PA stenting to catheter-based stenting and surgical arterioplasty for PA stenosis is necessary.