Transcatheter aortic bioprosthesis dislocation: technical aspects and midterm follow-up

Aims: Prosthesis dislocation during transcatheter aortic valve implantation (TAVI) is a rare but important complication. There is scarce data on the performance of prosthesis in the aorta that have become dislocated from their intended anatomical position in the aortic annulus. We investigated the causes of dislocation during TAVI of the self-expanding Core Valve ReValving (TM) System (CRS) (Medtronic Inc., Minneapolis, MN, USA). This included midterm follow-up of patients experiencing this acute complication. Methods and results: Among 176 consecutive patients undergoing TAVI with the CRS prosthesis, seven (3.9%) experienced acute valve dislocation. A comprehensive analysis of the mechanism of dislocation and clinical outcomes of patients experiencing this complication was performed. Based on the underlying mechanism, all cases of prosthesis displacement were classified into the following three groups: 1) accidental dislocation immediately after valve implantation (n=1; 14.3%); 2) dislocation during the snaring manoeuvre to reposition a low deployment of the CRS prosthesis (lower edge >10 mm) below the aortic annulus accompanied with haemodynamically significant regurgitation (n=4; 57.1%), 3) intentional dislocation performed with the snaring manoeuvre as a bailout in cases of coronary ostia impairment or severe prosthetic leak due to higher deployment for a suboptimal sealing of the device with valve calcifications (n=2; 28.6%). The majority of cases occurred during early experiences with the new Accutrak (TM) (Medtronic Inc., Minneapolis, MN, USA) delivery system. In six patients a second CRS was implanted in the appropriate position. The dislodged CRS functioned normally, without any evidence of structural deterioration, thrombosis or further distal migration and showed complete apposition against the aortic wall. No thromboembolic events were reported in any patient. Conclusions: Dislocation of a CRS device can be managed effectively with the implantation of a second device in a standard fashion leaving the dislocated device safely in the aorta. Intentional repositioning of a CRS device in the aorta can be accomplished by experienced operators without any serious neurologic or vascular events in the post-procedure period or at midterm follow-up.