Pitfalls and Safeguards in the Open Implantation of Mitral Transcatheter Valves in Patients with Increased Risk of Annulus Rupture

Introduction: Mitral valve stenosis with massive calcification of the annulus remains surgically challenging in respect of clinical outcome. Especially advanced age and accompanying multiorgan pathology increase both the intra-operative and the in-house mortality. Prolonged surgery time with threatening ventricular rupture and the so-called SAM-phenomes can be considered as a complex of causal factors. The aim of our alternative combined surgical-interventional approach was to reduce the risk of annual rupture and to avoid obstruction of the outflow tract.

Method: From December 2016 to July 2017, a total of 4 female patients (mean age was 79 years) with high-grade mitral valve stenosis based on calcified annulus underwent an open implantation of an Edwards Sapien III prosthesis using the heart-lung machine. Preoperatively, a CT examination for the assessment of mitral valve annulus calcification was performed in addition to TEE. Our explored interventional technique involved a partial resection of the AML and the placement with balloon expansion of the prosthesis under sight. In two cases were given a sutureless aortic valve replacement, in one case a myectomy according to Morrow and in one case a double myocardial revascularization. Additionally, in 3 patients, the left atrial was amputated or closed.

Results: Our pilot cohort revealed a 100% survival rate, a mean clamping time of 113.25 ± 30.9 minutes as well as an average HLM time of 163.5 ± 59.4 minute. Peri-interventionally, in 2 patients was a violation of the LV myocardium observed, which was successfully treated surgically. An additional suture fixation was necessary in 3 of 4 patients on the heart atrium side. The perioperative TEE showed in 3 patients an inconspicuous, heart valve-typical gradient on all implanted prostheses and a clinically irrelevant paravalvular leakage occurred in the anterior annulus. In the left ventricular outflow tract mild to moderately elevated gradients were recorded.

Conclusion: The open implantation of the Edwards-Sapien-prosthesis in patients with pronounced risk of mitral valve annulus rupture is a suitable and sufficient method to minimize surgical risk. Precondition for successful implantation is the knowledge of potential pitfalls and safeguards in this OFF-label procedure. Initial experience with the method can be used to develop appropriate prostheses in the future.

No conflict of interest has been declared by the author(s).