Pump thrombosis is an established complication of left ventricular assist devices (LVADs). Outflow graft obstruction has been previously described as one cause of LVAD thrombosis. We identified four cases of outflow graft obstruction that were attributed to a commonly applied polytetrafluoroethylene (PTFE) covering of the outflow graft. In this set of patients, the outflow graft was obstructed by a thrombus which formed between the outflow graft and its external PTFE covering, leading to impingement of the outflow graft. Patients typically presented after a median duration of 26 months (range 23–41 months) of support with gradual increase of heart failure symptoms and low pump flows. Computed tomography angiography was found to be the best diagnostic modality. Treatments included surgical LVAD replacement as well as percutaneous intraluminal stenting of the outflow graft. Our findings indicate that PTFE graft covering of the LVAD outflow graft can lead to graft occlusion and should be reconsidered as a potentially harmful modification to the approved device implant technique.

Background The Impella 5.5® was approved by the FDA for use for mechanical circulatory support up to 14 days in late 2019 at limited centers in the United States. Our single center’s experience with Impella 5.5® can expand the overall understanding for achieving successful patient outcomes as well as provide support for the expansion of its FDA-approved use. Methods This study is an IRB-approved single-center retrospective cohort analysis of hospitalized adult patient characteristics and outcomes in cases where the Impella 5.5® was utilized for mechanical circulatory support. Results A total of 26 implanted Impella 5.5® devices were identified in 24 hospitalized patients at our institution from January 2020 to January 2021. The overall survival rate during index hospitalization was 75%. Eleven Impella 5.5® devices were identified in 10 patients with an average device implantation greater than 14 days. Average device implantation for this subgroup was 27 days with a range of 15–80 days. Survival rate for Impella 5.5® use greater than 14 days was 67%. In the entire cohort and subgroup of device implantation > 14 days, evidence of end organ damage improved with Impella 5.5® use. Complications in our cohort and subgroup of device implantation > 14 days were similar to previously reported complication incidence of axillary inserted LVAD devices. Conclusions Our institution’s experience with the Impella 5.5® has been strongly positive with favorable outcomes and helps to establish the Impella 5.5® as a viable option for mechanical circulatory support beyond 14 days.

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