Driveline Fractures in the Heartmate II Left Ventricular Assist Device - A Single Center Experience in Asia

Purpose The incidence of driveline fractures among patients on HeartMate II Left Ventricular Assist Device (LVAD) support is reviewed Methods This is a single-center, retrospective review of all the patients on HeartMate II LVAD support who presented with driveline fractures. Patients’ presentation, interventions, and outcome following corrective treatment were examined. Results Between May 2009 and October 2018, 60 HeartMate II LVAD were implanted. Over a cumulative support period of 81 patient-years (maximum, 8.5 years), 15 patients (25%) had driveline fractures (age 14-70, 2 female), 5 of them were destination therapy (> 65 years old). Mean duration from the time of implant to driveline fractures was 44.5 ± 15.5 months. 12 patients had significant weight gain following LVAD implant, ranging from 5.2 to 32.3kg (median 17.4kg). While tethered on to power module, 8 patients (53.3%) encountered intermittent pump stoppage, 5 (33.3%) had transient low pump speed, 1 (6.7%) had recurrent driveline fault and 1 more (6.7%) presented with hemoserous discharge leaking from broken insulation in the external driveline with multiple recurrent low voltage advisory. Ungrounded cable was issued to 13 patients as a temporary measure with mean duration of its usage of 259 days (range 26-980 days), before corrective treatment. There were 2 patients with ongoing use of the ungrounded cable (mean 1 year). 8 patients (53.3%) underwent pump replacement, 2 with significant external driveline fractures successfully underwent external driveline replacement and 1 underwent heart transplant. Of the 9 pumps returned for analysis, 7 (78%) were found to have damaged internalized part of the driveline while 2 (22%) had circumferential fractures at the edge of the pump housing extending across the diameter of the bend relief. There were 3 mortality (20%), 1 due to recurrent pump pocket infection and pump thrombosis following the initial pump replacement for driveline fractures, 1 died of subdural haemorrhage before elective pump exchange and 1 died 3 weeks after pump stoppage. Conclusion The incidence of HeartMate II internal driveline fractures seemed to be higher in our Asian experience as opposed to what have been reported in literature. An ungrounded cable served as a temporary measure for short to shield and a timely pump exchange maybe lifesaving when driveline damage progressed into phase to phase.