Use of Three-Dimensional Printing for Closure of Multiple Muscular Ventricular Septal Defects

Abstract

Purpose: Multiple muscular ventricular septal defects (VSDs) are located in parts of the septum which are difficult to access surgically. The main challenge surgically remains identification of all defects intraoperatively, without which residual defects are inevitable. Patient-specific three dimensional (3D) printed models can help demonstrate intracardiac anatomy with accuracy. We present our experience in using this technology to surgically close otherwise inaccessible multiple muscular VSDs for the first time. Methods: All patients between September 2021 to April 2023 with multiple VSDs in whom a 3D printed model was used to aid surgical planning were included in the study. Patient data was collected retrospectively. All patients underwent a pre-operative computerised tomography scan from which 3D images were compiled by the cardiac radiologist. This data was used by the 3D engineer to construct the 3D model using specialised software package. The model was then used to precisely identify the multiple VSDs and plan surgical intervention. Results: Between September 2021 and April 2023, 5 patients underwent closure of multiple VSDs using a 3D model. 3 patients were previously deemed unsuitable for biventricular repair and were planned for Fontan palliation. 4 (80%) patients were male. Median age at surgery was 3.9 years (IQR 1.3–6.6). Median weight was 15.5 kg (IQR 14–17.7). 4 (80%) patients had previously undergone pulmonary artery (PA) banding. 2 patients had previous aortic arch repair. The VSDs were approached through the right atrium in 2 (40%) patients, and through the right ventricle in 3 (60%) patients. Crossing muscle bundles were resected converting the multiple defects into a single confluent defect which was then closed with a patch. Additional procedures included PA de-banding (n=4), and aortic valve repair (n=1). Median cardiopulmonary bypass and myocardial ischaemia time were 209 minutes (IQR 117–217) and 149 minutes (IQR 86–186), respectively. There was no heart block and no patient had a haemodynamically significant residual VSD. The median follow-up was 5.4 months (IQR 1.48–9.88). All patients had no haemodynamically significant residual VSDs. Conclusion: The use of 3D printing to aid closure of multiple ventricular septal defects is safe, reliable, and reproducible. We recommend the addition of 3D printing to the armamentarium of surgeons dealing with the challenge of closing multiple muscular VSDs in children.