Evidence of leaflet injury during percutaneous aortic valve deployment

It has been suggested that valved stent deployment during transcatheter aortic valve implantation may be responsible for traumatic injury to pericardial leaflets, especially with balloon expandable valved stents. However, such an injury has not been described nor reported so far. We here report the microscopic analysis of 4 Sapien-Edwards prostheses, 2 of which have been implanted in humans. There was no macroscopic evidence of traumatic injury to the pericardial leaflets of the percutaneous valves. However, pathological microscopic findings were observed in all of them. These mainly consisted of collagen fibers fragmentation and disruption. Areas of non- or mildly affected tissue were adjacent to areas of severely damaged tissue. The entire thickness of the leaflets might be involved. The severity of the lesions also differed among leaflets from a same prosthesis. Areas of plasmatic insudation were identified in one case. The disruption index was significantly higher in the Sapien group in comparison to the control group: 42.4% (14-63.5%) versus 17.5% (9.2-31%) (p < 0.001). Although of limited size sample, this study does prove that traumatic injury to leaflets occurs during percutaneous valves implantation. This should prompt physicians to wait for the long-term results of this new technology before extending the indications to low-risk patients.