Ventricular Septal Defect as a Complication of TAVI: Mechanism and Incidence

Introduction: Ventricular septal defect (VSD) is a rare complication of transcatheter aortic valve implantation (TAVI). Several underlying mechanisms have been proposed including rupture of the membranous septum by valve struts, penetration of the stiff wire, or balloon induced trauma. Most reported VSDs have been asymptomatic; however, others are symptomatic with potentially severe complications. The present study examined the incidence, clinical presentation and putative mechanism of TAVI associated VSD.

Method and Results: Four-hundred patients who underwent TAVI in three tertiary centers in Israel during 2015 were retrospectively reviewed for cases of procedural associated VSD. Six patients with post procedural VSD (1.5%) were identified by trans-thoracic echocardiography. Three of the patients were implanted with Edwards Sapien (two with S3 valve and one with XT) bioprosthetic valve;
the other three patients were implanted with Medtronic Corevalve bioprosthetic valve (two with Evolut and one with Corevalve "classic"). Procedural course was uneventful and valves were deployed according to product guidelines. Post-procedural echocardiography revealed small, restrictive, left-to-right shunt VSD; in four of the six cases the VSD was located in the membranous part of the septum, while in the other two cases the VSD is located in the apical region of the septum. All patients were hemodynamically and clinically stable during hospital stay, the VSD and did not require additional intervention.

Conclusion: VSD is a rare complication of TAVI that is most probably underdiagnosed. Clinical course is benign with no need for immediate intervention. The mechanisms underlying VSD formation include local trauma by the valve’s struts onto the membranous septum, and apical septum injury caused by the stiff wire. Long term follow-up is warranted to further elucidate the sequel of this complication.