Minimally Invasive Implantation of Continuous Flow Left Ventricular Assist Devices: The Evolution of Surgical Techniques in a Single-Center Experience

Abstract

In this work we aimed to evaluate the evolution of our surgical experience with the implantation of a continuous flow left ventricular assist device (LVAD), from the original full sternotomy approach to less invasive surgical strategies including mini-sternotomy and/or mini-thoracotomies. We reviewed all consecutive patients implanted with a continuous flow LVAD at our Institute. To exclude the possible bias related to the device used, out of 91 collected LVADs implants, we selected only those patients (n = 42) who received, between 2012 and 2015, the HeartWare HVAD. The analysis focused on the surgical approach used for the LVAD implant. Most of the patients (95%) were affected by dilated or ischemic cardiomyopathy, with an INTERMACS class I-II in the majority of cases (77%). The LVAD implant was performed through a full sternotomy in 10 patients (24%); the remaining 32 cases (76%) were managed with minimally invasive procedures. These were left mini-thoracotomy with upper mini-sternotomy (20 patients, 62%), right and left mini-thoracotomy (7 patients, 22%), and a recently developed left mini-thoracotomy with outflow graft anastomosis to the left axillary artery (5 patients, 16%). The most common adverse event on device was right heart failure (26%). Eighteen patients (43%) were transplanted. Overall estimated 24 months survival (on device or after transplant) was 68 ± 7%. The causal analysis, adjusted by propensity score weighting baseline data and sample size, showed that left mini-thoracotomy with outflow anastomosis to the left axillary artery resulted in a significantly reduced rate of post implant right heart failure (P < 0.01), and mechanical ventilation time (P = 0.049). To conclude, in our series, by applying mini-invasive implant techniques in the majority of cases, mid-term survival of continuous flow LVADs in severely compromised patients was satisfactory. In the adjusted analysis, the left anterior mini-thoracotomy with outflow anastomosis to the left axillary artery showed the most favorable results.

Keywords: HVAD; HeartWare; Implant; Left ventricular assist device; Minimally invasive; Surgical technique.