Early Distal Migration of a Self-Expanding Aortic Valve Prosthesis Causing Myocardial Infarction

Macroscopic and microscopic features of surgically explanted transcatheter aortic valve prostheses

OBJECTIVES

With the extended indications of transcatheter aortic valve (TAV) replacement (TAVR) to lower-risk patients, there is an increasing number of patients requiring surgical explantation of failed TAV. We sought to describe macroscopic and microscopic features of surgically explanted percutaneous aortic valve prostheses.

METHODS

Preoperative and surgical characteristic of patients undergoing surgical explantation of TAV were retrospectively analyzed from 2007 to 2020. Surgical and pathologic features of these valves, and outcomes of the surgical valve replacement were described.

RESULTS

Out of 1764 patients who underwent a TAVR procedure, 21 were operated for TAV failure. Isolated or combined indications for surgery included: significant paravalvular leak (n = 15), delayed prosthesis migration (n = 5), significant increase of trans-TAV gradients (n = 6), and endocarditis (n = 3). Mean time elapsed between TAVR and explantations was 674.9 ± 803.9 days. Macroscopic lesions found on explanted percutaneous valves were severe adhesions to the aorta (n = 10), calcifications (n = 7), leaflet thrombosis (n = 4), and vegetations (n = 3). Except for patients with endocarditis, one or more pathological lesions were found in 15 patients. Pathology analyses on these valves showed fibro-calcific degenerations (n = 12), pannus formation (n = 9), and chronic inflammation (n = 3). One patient (4.8%) died after surgical explantation, and 13 (61.9%) had concomitant procedures. The survival rate at 1 year was 94.4%.

CONCLUSIONS

Microscopic findings of fibro-calcific leaflet degeneration, and pannus formation in addition to macroscopic calcification and thrombosis present early, (within a mean of 2 years) after TAVR. Further investigation with a higher number of patients and echocardiographic follow-up is warranted.

Surgical explantation of transcatheter aortic bioprostheses: Results and clinical implications

OBJECTIVE

Despite the rapid adoption of transcatheter aortic valve replacement (TAVR) and worldwide interest in its implantation, TAVR valve explantation has not been well described.

METHODS

We retrospectively reviewed 1442 consecutive patients who underwent a TAVR procedure between 2011 and 2019, in which TAVR explantation was performed in 15 patients (1.0%). In addition, 2 patients from outside institutions also underwent TAVR explantation at our institution. We reviewed the clinical details of these 17 patients.

RESULTS

The frequency of TAVR explant increased over time from 0 to 1 during the period from 2011 to 2015 to 6 in 2019. The mean age was 73.0 ± 9.3 years. The majority of patients (88.2%) were in New York Heart Association functional class IV heart failure. The Society of Thoracic Surgeons Predicted Risk of Mortality score was significantly higher at the time of explantation than at the time of the original TAVR (3.5% vs 9.9%; P < .001). The indication for explantation included structural valve degeneration (23.5%), severe paravalvular leak (41.2%), TAVR procedure-related complications (23.5%), endocarditis (5.9%), and bridge-to-definitive surgery (5.9%). Neoendothelialization of the TAVR valve into the aortic wall requiring intense aortic endarterectomy was noted in all 5 of the TAVR valves older than 1 year, in which 2 (40%) required unplanned aortic root repair. There were 2 (11.8%) in-hospital mortalities.

CONCLUSIONS

Surgical TAVR valve explant is increasing and may become common in the near future. The clinical effects of explanting chronically implanted valves with the potential need for aortic repair is not negligible. These data should be used to more appropriately select TAVR candidates as TAVR practices expand into younger and lower risk patients.