Comparing HVAD Inflow Cannula Angle between Median Sternotomy and Thoracotomy

Abstract

<h3>Purpose</h3> Left ventricular assist device (VAD) implantation via thoracotomy is a safe operation with potential advantages compared to conventional sternotomy. One proposed advantage is improved inflow cannula (IFC) positioning due to better visualisation. We investigated the difference in IFC angles for patients with HVADs implanted via these techniques and compared post-operative as well as long term outcomes. <h3>Methods</h3> 42 patients were retrospectively selected from our VAD database. 28 in the sternotomy group and 14 in the thoracotomy group. We included all thoracotomy implants performed at our centre and consecutive sternotomy implants from 2015-2019. Inclusion required a minimum support time of 30 days. Patients with concomitant procedures were excluded. The first post-operative CT chest scan was used to measure the angle between the IFC and mitral valve in axial and coronal planes. <h3>Results</h3> There was no significant difference in gender, INTERMACS score, BMI or age between the two groups. Median support time was not significantly different between the thoracotomy and sternotomy groups (328 vs 360 days, p=0.9). Median cardiopulmonary bypass (CPB) time was higher in the thoracotomy group (104 vs 78 minutes, p<0.01). Median ICU length of stay for the thoracotomy group was 5 days compared to 8 days in the sternotomy group, p=0.08. There was no significant difference in median IFC angle on the axial plane between the thoracotomy group and the sternotomy group (9 degrees v 10 degrees, p=0.3). Similarly, there was no difference in the coronal plane (9 degrees vs 12 degrees, p=0.9). Rates of pump thrombosis, stroke and GI bleeding were not significantly different between the two groups. <h3>Conclusion</h3> In our sample size of 42 patients, the thoracotomy group had a slightly longer CPB time, however, there was no difference in IFC angle, pump thrombosis, GI bleeding, stroke or ICU length of stay. In saying this, there may be other benefits to the thoracotomy approach such as facilitating easier sternal entry upon transplantation.