Gore-Tex Mesh as Cause for Distal Outflow Graft Obstruction in Ventricular Assist Device Patients

Abstract

Purpose Re-do sternotomy following left ventricular assist device (LVAD) implant can occur due to cardiac transplantation or device complication. A polytetrafluoroethylene membrane (Gore-Tex) has been used to cover portions of the outflow graft to reduce adhesions. We describe 3 cases of late-presenting extrinsic compression of the distal outflow graft from a Gore-Tex membrane in both HVAD and HMII devices. Methods We conducted a retrospective analysis of all LVAD implants which included a Gore-Tex membrane at our institution between 1/2012-6/2018. We defined cases of extrinsic outflow graft obstruction (OGO) by clinical presentation, CT imaging, and intraoperative findings. Results During the study period, 158 LVADs with tubular Gore-Tex outflow graft coverage were implanted (93 HVAD, 59 HM2, 4 HM3). Three cases of extrinsic OGO (1 HVAD, 2 HM2) were identified, for a cumulative incidence of 1.9% (1.44 per 100 patient years). The average time to clinical presentation was 1157 ± 155 days. Each case presented with persistent low-flow alarms detected via remote monitoring in the absence of power spikes or clinical symptoms. Markers of hemolysis (LDH, plasma free hemoglobin) were normal, INR was therapeutic, and echocardiograms did not indicate volume depletion or right ventricular failure. In each case, CT imaging demonstrated critical narrowing of the distal outflow graft (N=2) or aortic anastomosis (N=1) (Fig A). Each patient underwent surgical exploration; upon incision of the overlying Gore-Tex membrane, a proteinaceous material was drained resulting in immediate improvement in flows and avoidance of pump exchange (Fig B). Conclusion We highlight 3 cases of a previously undescribed mechanism of OGO by extrinsic compression, resulting from accumulation of proteinaceous material underneath the Gore-Tex membrane. Each presented with gradual onset of low flows without additional symptoms, suggesting that a high level of clinical suspicion is necessary to ensure appropriate management.