Kevin R An

and 6 more

Objectives Redo sternotomy and explantation of left ventricular assist devices (LVAD) for heart transplantation (HT) involve prolonged dissection, potential injury to mediastinal structures and/or bleeding. Our study compared a complete expanded polytetrafluoroethylene (ePTFE) wrap versus minimal or no ePTFE during LVAD implantation, on outcomes of subsequent HT. Methods Between July 2005 and July 2018, 84 patients underwent a LVAD implant and later underwent HT. Thirty patients received a complete ePTFE wrap during LVAD implantation (Group 1), and 54 patients received either a sheet of ePTFE placed in the anterior mediastinum or no ePTFE (Group 2). Results Baseline characteristics were similar between Groups 1 and 2. Surgeons reported subjective improvements in speed, predictability and safety of dissection with complete ePTFE compared with minimal or no ePTFE. Time from incision to initiation of cardiopulmonary bypass (CPB) were similar between groups (97±38 min vs 89±29 min, p=0.3). Injury to mediastinal structures during the dissection was similar between groups (10% vs 11%, p>0.9). While surgeons reported less intraoperative bleeding in Group 1 (43% vs 61%), this trend did not reach significance (p=0.1). In-hospital mortality, ICU length of stay and hospital length of stay were similar between both groups. Conclusions In patients undergoing LVAD explant-HT, there was a trend towards reduced surgeon reported intraoperative bleeding with ePTFE placement. Despite qualitatively reported greater ease and speed of mediastinal dissection with ePTFE membrane placement, time to initiation of CPB did not differ, likely because surgeons remained cautious, allowing extra time for unanticipated difficulties.
Background Ex-situ heart perfusion (ESHP) has been developed to decrease cold ischemia time and allow metabolic assessment of donor’s hearts prior to transplantation. Current clinical ESHP systems preserve the heart in an unloaded condition and only evaluate the cardiac metabolic profile. In this pilot study we performed echocardiographic functional assessment using two alternative systems for left ventricular (LV) loading: Pump Supported Afterload Working Mode (SAM) and Passive Afterload Working Modes (PAM). Methods Six hearts were procured from male Yorkshire pigs. During cold ischemia, hearts were mounted on our custom made ESHP circuit and a 3D printed enclosure for the performance of echocardiography with a standard TEE probe. Following perfusion with Langherdorf mode of the unloaded heart, the system was switched into different working modes to allow LV loading and functional assessment: pump supported (SAM) and passive (PAM). Echocardiographic assessment of left ventricular function in the donor hearts was performed in vivo and at 1h of ESHP with SAM, after 4.5h with PAM and after 5.5h with SAM. Results We obtained good quality epicardial echocardiographic images at all time points allowing for comprehensive LV systolic assessment. All indices showed a decrease in LV systolic function throughout the trial with the biggest drop after heart harvesting. Conclusion We demonstrated the feasibility of echocardiographic functional assessment during ESHP and two different working modes. The expected LV systolic dysfunction consisted of a reduction in EF, FAC, FS, and Strain throughout the experiment with the most significant decrease after harvesting.