Perventricular Device Closure of Residual Muscular Ventricular Septal Defects after Repair of Complex Congenital Heart Defects in Pediatric Patients

Residual muscular ventricular septal defects are surgical challenges, especially after the repair of complex congenital heart defects. We investigated perventricular device closure as a salvage technique in pediatric patients who had postoperative residual muscular ventricular septal defects.From February 2009 through June 2011, 14 pediatric patients at our hospital had residual muscular ventricular septal defects after undergoing surgical repair of complex congenital heart defects. Ten patients met our criteria for perventricular device closure of the residual defects: significant left-to-right shunting (Qp/Qs >1.5) or substantial hemodynamic instability (a defect ≥2 mm in size). The patients'' mean age was 20.4 ± 13.5 months, and their mean body weight was 10 ± 3.1 kg. The median diameter of the residual defects was 4.2 mm (range, 2.5–5.1 mm).We deployed a total of 11 SQFDQ-II Muscular VSD Occluders (Shanghai Shape Memory Alloy Co., Ltd.; Shanghai, China) in the 10 patients, in accord with conventional techniques of perventricular device closure. The mean procedural duration was 31.1 ±9.1 min. We recorded the closure and complication rates perioperatively and during a 12-month follow-up period. Complete closure was achieved in 8 patients; 2 patients had persistent trivial residual shunts. No deaths, conduction block, device embolism, or other complications occurred throughout the study period.We conclude that perventricular device closure is a safe, effective salvage treatment for postoperative residual muscular ventricular septal defects in pediatric patients. Long-term studies with larger cohorts might further confirm this method''s feasibility.Key words: Cardiac surgical procedures/instrumentation/methods, equipment design, heart defects, congenital/adverse effects, heart septal defects, ventricular/complications/pathology/therapy, hemodynamics, postoperative complications, prostheses and implants, surgical procedures, minimally invasive/methods, treatment outcomeMuscular ventricular septal defects (VSDs) constitute approximately 20% of all VSDs¹ and are possibly associated with other complex congenital heart conditions, such as tetralogy of Fallot and double-outlet right ventricle.² Surgical closure is the mainstay treatment for most VSDs; however, muscular VSDs cannot be approached adequately without a ventricular incision, especially when associated with a large left-to-right shunt, pulmonary hypertension, or interventricular septal hypertrophy.^3–5 After complex congenital heart defects with severe left-to-right shunting are repaired, residual muscular VSDs can significantly increase the patient''s risk of death.^4,5Particularly in pediatric patients, postoperative residual muscular VSD poses a surgical challenge. Open surgical repair is associated with repeat cardiopulmonary bypass (CPB), the risk of ventriculotomy because of an inadequate operative field of vision, and postoperative ventricular dysfunction.^5,6 Fluoroscopically guided transcatheter device closure is another treatment option; however, restricted vascular access and the technical difficulty of this procedure are well documented in pediatric patients. Radiation exposure and hemodynamic instability during device positioning can also compromise the prognosis.^2,7Perventricular device closure of VSDs with transesophageal echocardiographic (TEE) guidance was first reported by Amin and colleagues.⁸ This method enables direct access, which is especially suitable in closing apical muscular VSDs.⁹ We investigated the feasibility of perventricular device closure as a salvage procedure in pediatric patients who had residual muscular VSDs after having undergone repair of complex congenital heart defects.