D. Sandler

Intraperitoneal pocket for left ventricular assist device placement

BACKGROUND Implantation of the HeartMate Implanted Pneumatic or Vented Electric Ventricular Assist Device requires that the pump be implanted either in the peritoneal cavity or in the abdominal wall. Both sites have been problematic. METHODS We describe a new technique in which an intraperitoneal pocket is created, using Gore-Tex Dual Mesh Plus Biomaterial with Holes, to contain the ventricular assist device. This shields the ventricular assist device from the peritoneal contents and avoids abdominal wall dissection. Thirty consecutive patients who underwent implantation using this technique were compared with 16 patients who underwent implantation before this technique was in use. RESULTS Thirty consecutive patients underwent implantation, and 2 of those patients underwent re-implantation because of device failure (16/30 HeartMate Implanted Pneumatic, 14/30 HeartMate Vented Electric, and 2/14 HeartMate Vented Electric replaced with the HeartMate Implanted Pneumatic). Twenty-five patients have undergone explantation. Pocket infections in patients who have had implanted devices for >1 month decreased from 4 of 13 before the pockets were used to 1 of 25 with the intraperitoneal pockets (Fishers exact test p = 0.038). Two hernia repairs were required after explantation when the biomaterial pocket was used. A decrease in return to surgery for bleeding was noted after the pocket was used (7/16 without the pocket and 3/32 with the pocket; Fishers exact test, p = 0.010). CONCLUSIONS Bleeding complications and pocket infections decreased in this early experience. Further study is necessary to confirm the apparent decrease in complication rate by using this new technique in this small cohort of patients.

1147-210 Implantable cardiac defibrillator interactions with magnetic resonance imaging at 1.5 tesia

Background: Cardiac magnetic resonance imaging (MRI) is a commonly used modality to help differentiate patients with right ventricular outflow tract (RVOT) tachycardia and those with arrhythmogenic right ventricular dysplasia (ARVD). Both of these groups of patients present with monomorphic ventricular tachycardia (VT) arising from the right ventricle. Methods and Results: Patients were diagnosed with ARVD and RVOT tachycardia using standard clinical criteria. Thirteen ARVD patients underwent cardiac MRI; 5 had normal scans and 8 had findings suggestive of ARVD (including fatty infiltration, fibrosis, and right ventricular wall thinning, hypokinesis, or dyskinesis). Thirty-seven patients with RVOT tachycardia underwent cardiac MRI; of these 26 were normal and 11 were abnormal. Therefore, the positivity rate of MRI was 62% in ARVD pts, and the negativity rate in RVOT pts was 30%. Conclusions: These findings suggest that abnormalities of the right ventricle seen on cardiac MRI appear to be nonspecific for ARVD. In addition, the sensitivity of MRI imaging in detecting patients with ARVD is suboptimal, as these pts not uncommonly have normal or only mildly abnormal cardiac MRI scans, especially early in the disease process.

Thrombolytics in VAD management — A single-center experience

Background With continued increase in the use of mechanical circulatory support, the incidence of device thrombus remains a challenge. This study is a retrospective analysis of data at a single center to assess the safety and efficacy of thrombolytic use in durable mechanical assist devices. Methods Data was analyzed retrospectively from 154 patients who underwent left ventricular assist device (LVAD) implantation from 1/1/2005 to 6/30/2014. The HMII device was implanted in 131 patients while 23 received the HVAD. LVAD thrombus was diagnosed when lactate dehydrogenase levels exceeded 1000 units/l accompanied by clinical signs of hemolysis and heart failure, echocardiographic data and surges in pump power. TPA (tissue plasminogen activator) protocol consisted of a 5 mg intravenous bolus followed by 3 mg/h infusion in normal saline for 10 h. If symptoms persisted another cycle of TPA at 1 mg/h was continued up to 48 h. Results The TPA group had a 70% success rate. Success was defined as complete resolution of hemolysis and clinical symptoms with no requirement for LVAD exchange at 30 days. 95% survival was noted at 30 days and 90% were free of a hemorrhagic stroke in the TPA group. The rates of hemorrhagic strokes in the TPA group and the control group were not different (OR = 0.92). Conclusion The TPA protocol described here was successful consistently. Though this study is limited by its size and retrospective nature it leads the way for larger studies to generate more robust comparisons between different types of mechanical assist devices as well as the tailored use of thrombolytics in this patient population.