Safety and Efficacy of Pressure Regulated Deployment of Balloon-expandable Transcatheter Aortic Valve Implantation (TAVI)

Abstract

Introduction: Currently no optimal strategy exists for deployment of balloon-expandable transcatheter aortic valves. Prosthesis oversizing is associated with the devastating complication of aortic annular rupture as well as increased post-procedural atrioventricular conduction disease. Conversely, valve undersizing is associated with greater paravalvular regurgitation and poor long-term outcomes. We propose a novel pressure regulated deployment strategy that enables optimal apposition between prosthesis and annulus while also carefully preventing significant annular overstretching and injury. Methods: 251 consecutive patients underwent TAVI procedure with balloon-expandable valves across two Australian centres. Prosthesis sizing was determined using device manufacturer and previously published charts. In all patients the valve prosthesis was deployed using a pressure regulated expansion strategy. Following initial deployment, an additional intraprocedural post-dilatation with Balloon Aortic Valvuloplasty was occasionally performed to reduce paravalvular leak. 41 patients underwent prosthesis implantation that would have otherwise resulted in >20% oversizing by traditional volume expansion. For this group the deployment pressure was limited to 5.5 atm. Results: No cases of aortic annular rupture occurred and overall rates of PPM insertion and development of new LBBB were 6.3% and 12.2%, respectively. There was no significant association between the degree of valve oversizing and sustained postprocedural conduction disease. However, there was a strongly significant inverse relationship between valve oversizing and resulting paravalvular leak. Higher deployment pressures resulted in fewer post-dilatation BAV. Conclusion: Pressure regulated deployment of transcatheter aortic balloon-expandable valves is a safe and efficacious strategy.