Stent Frame Infolding of a 34-mm Evolut-R in a Patient With a Mechanical Mitral Valve

Infolding of Evolut PRO+ during transcatheter aortic valve implantation and bailout by post-balloon dilation: A case report

An 89-year-old man with symptomatic severe aortic stenosis underwent transcatheter aortic valve implantation due to old age and a history of coronary artery bypass grafting. Computed tomography showed a tricuspid aortic valve and severe calcification at the aortic valve annulus, with a perimeter of 88.7 mm. The 34-mm Evolut PRO+ (Medtronic Inc., Minneapolis, MN, USA) was selected. After balloon aortic valvuloplasty, deployment of the Evolut PRO+ was attempted, but significant expansion failure was observed. Upon retraction and removal of the Evolut PRO+ from the body, frame deformation was observed. A new Evolut PRO+ was tried again, but a similar finding was noted as a magatama-like infolding on transesophageal echocardiography. Fortunately, the patient's hemodynamics were relatively stable. Post-dilation was performed using a 25 mm Z-MED II (NuMED, Inc., Montreal, Canada) for reshaping.

Learning objective

In self-expanding transcatheter aortic valves (TAVs), bending of the TAV frame is widely known as one of the key problems. However, this is rare and infrequently encountered. In this case, TAV frame infolding occurred repeatedly, and the morphology of the infolding was evaluated in vitro and in vivo. Furthermore, we report that some TAVs can be reshaped by post-dilation.

Pre-dilation and Post-dilation in Transcatheter Aortic Valve Replacement: Indications, Benefits and Risks

Transcatheter aortic valve replacement (TAVR) is an established treatment for patients with symptomatic severe aortic stenosis. In recent years, an emphasis has been placed on simplification of the procedure. Balloon predilation was initially considered a mandatory step to cross and prepare the stenotic aortic valve, but several studies demonstrated the feasibility of performing TAVR without balloon valvuloplasty. Balloon postdilation of the implanted valve is sometimes required to optimise results, although many patients do not require this step. Contemporary consensus advocates an individualised approach to TAVR procedures and so balloon pre- and post-dilation are performed selectively. This review aims to outline the advantages and disadvantages of balloon pre- and post-dilation and to identify the scenarios in which they are required during TAVR procedures.

Self-expanding transcatheter aortic valve infolding: Current evidence, diagnosis, and management

BACKGROUND

Prosthetic valve infolding is a rare but severe complication of transcatheter aortic valve implantation (TAVI) with self-expanding valves. However, currently available clinical data are limited and fragmented.

OBJECTIVES

This report aims to provide a comprehensive overview of this complication focusing on predisposing factors, clinical presentation, diagnostic findings, treatment and clinical outcomes.

METHODS

A systematic review of the literature was performed to identify cases of infolding occurring during TAVI with self-expanding valves published until August 2020. These data were pooled with all the retrospectively identified infolding cases occurred at San Raffaele Scientific Institute between December 2014 and August 2020.

RESULTS

A total of 34 cases were included. Among patients with available data, 38% received a first-generation CoreValve, and 62% a second-generation Evolut R (82%) or Evolut PRO (18%). Infolding occurred mostly with ≥29-mm valves (94%). Predisposing factors included resheathing of a second-generation valve (82%), heavy calcification of the native valve (65%), lack of predilatation (16%), Sievers type-1 bicuspid aortic valve (11%), and improper valve loading (5%). Infolding resulted in severe PVL causing hemodynamic instability (29%) or cardiac arrest (12%). Postdilatation was the treatment strategy in 68%, while prosthesis replacement with a new device in 23% of cases. Device success rate was 82%. Death and stroke occurred in 3% and 12% of cases.

CONCLUSIONS

Prosthetic valve infolding is typically observed after resheathing of a large-size self-expanding TAVI. When infolding is timely diagnosed, prosthesis removal and replacement should be pursued. Further studies are required to precisely define predisposing factors to prevent this complication.