Rupture of a calcified right ventricle to pulmonary artery homograft by balloon dilation- emergency rescue by venus P-Valve.

Abstract

Background: Percutaneous pulmonary valve implantation (PPVI) is a recognized alternative treatment to surgery for patients with dysfunctional right ventricular outflow tracts. Patient selection is essential to avoid serious complications from attempted treatment, such as rupture or dissection, especially of the calcified outflow tracts. We describe a case with an unexpected rupture of a calcified homograft valve and main pulmonary artery, which was treated successfully by emergency implantation of a self-expanding Venus P-Valve (Venus MedTech, Hangzhou, China) without the need for pre-stenting with a covered stent.

Case details: A 13-year-old boy had two previous operations of tetralogy of Fallot, one a total repair and the other a homograft valved conduit for pulmonary regurgitation. He presented with dyspnea and severe right ventricular outflow tract obstruction (RVOTO) and had a calcified outflow tract and main pulmonary artery. In the catheter laboratory, a non-compliant balloon dilation resulted in a contained rupture of the conduit. The patient remained hemodynamically stable, and the rupture was treated with a self-expandable Venus P-Valve without the need for a covered stent combined with a balloon-expandable valve or a further surgical procedure.

Discussion: Preprocedural evaluation with an inflating balloon is necessary to examine tissue compliance and determine suitability for PPVI. However, this condition is accompanied by a risk of conduit rupture. Risk factors of this complication are calcification and homograft use. These ruptures are mostly controlled with a prophylactic or therapeutic covered stent, with a low rate of requiring surgery. However, there are severe ruptures which lead to hemothorax and death. In the available literature, there was no similar reported case of conduit rupture, which a self-expandable Pulmonary valve stent has managed. It seems that fibrosis and collagen tissue around the heart, formed after open surgeries, can contribute to the control of bleeding in these cases.

Conclusion (clinical learning point): The suitability of patients for the PPVI procedure should be examined more carefully, specifically patients with homograft and calcification in their conduit. Furthermore, conduit rupture might be manageable with self-expandable artificial pulmonary valves, specifically in previously operated patients, and the applicability of this hypothesis is worth examining in future research.