Article Abstract

Radiopaque preventive landmarks’ placement during stentless bioprosthesis implantation

Authors: Niki Lama, Vasileios Patris, Dimitrios Fagkrezos, Petros Moschouris, Konstantinos Giakoumidakis, Charikleia Triantopoulou, Petros Maniatis, Mihalis Argiriou

Abstract

Background: In patients with aortic stenosis, bioprosthetic valves are increasingly used. Although their benefits, they are also presenting limitations, as their time-related degeneration. Reoperation which was, until a few years ago, the only treatment for this condition, carries a significant surgical risk, especially in patients with multiple comorbidities, so the benefit of less invasive technique enabling the implantation of aortic valve prosthesis [transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV)] by a percutaneous access is remarkably important. Eligible patients are judged by a heart team, and imaging plays a key role in this selection, focusing on correct identification of bioprosthetic aortic valves type and size, evaluation of patients at increased anatomical risk for coronary artery occlusion. Radiolucency of stentless bioprosthetic valves, represent a significant challenge.
Methods: Surgical aortic valve replacements (SAVRs) with a bioprosthesis were performed using a stentless valve with no radiopaque components (Solo Smart, Sorin). The chosen method, in order to evaluate the results of the operation, was computed tomography (CT) scanning (64-slice MDCT, Brilliance, Philips). The study consisted of a thin sliced contrast electrocardiograph (ECG) gated chest CT (1 systolic cardiac phase), trying to simulate the required assessment of aortic root and the radiopaque placed markers.
Results: As surgical implant technique varies and may impact the relationship of the prosthetic annulus to the coronary ostia, marking the aortic annulus during the operation in order to have some useful radiopaque landmarks, is a great assistance promoting better orientation and correct identification of the position of the bioprosthetic valve. Although the implantation of metallic vascular clips at the level of aortic annulus (in any commissure or in the middle of any cups) was considered, the decision was to position three metallic clips bellow the aortic annulus in the three stiches ligated during the solo valve implantation.
Conclusions: We are suggesting the preventive implantation of radiopaque landmarks, during SAVRs using tissue valves which are lacking fixed anatomic markers, as a guide for a presumptive TAV-in-SAV procedure, keeping in mind that appropriate guidance is crucial and can prevent valve misplacement, coronary obstruction and other potentially lethal complications.