Extended in vivo evaluation of a miniaturized axial flow pump with a novel inflow cannula for a minimal invasive implantation procedure.
ABSTRACT Minimally invasive techniques are desirable to minimize surgical trauma during left ventricular assist device (LVAD) implantation. This is particularly challenging for full-flow support. In this study, a minimally invasive implantation technique was developed for a microaxial rotary pump. The system was evaluated in a chronic sheep model.
A HeartWare MVAD (HeartWare, Miami Lakes, FL) pump (length, 50 mm; diameter, 21 mm; maximum flow, 7-8 liters/min) was combined with a novel inflow cannula, including a new flow-optimized tip. The device was implanted into sheep (range, 60-80 kg, mean, 71.6 ± 6.8 kg) through a right-sided minithoracotomy. The inflow cannula was inserted through the superior pulmonary vein, passing through the left atrium into the left ventricle. Scheduled implant period was 30 days for 8 sheep and 100 days for 3 sheep. Mean support flow was set to half of the nominal cardiac output.
Six of 8 sheep finished the scheduled 30-day investigation period (one failed due to early non-pump-related post-operative bleeding and one due to prototype controller failure). The 3 sheep scheduled for 100 days reached the study end point. Peak pump flows of up to 6.9 liters/min were achieved. At necropsy, no signs of mitral valve lesions or thrombus formation around the cannula, the tip, or the insertion site were observed, except for valve leaflet erosion in 1 animal, where the cannula had been entangled in the sub-valvular chords due to lack of ultrasound monitoring.
The minimally invasive implantation technique using the HeartWare MVAD pump, together with a new cannula, provided excellent results in a chronic animal model.
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ABSTRACT: Mechanical circulatory support of the failing heart has become an important means of treating end-stage heart disease. This rapidly growing therapeutic field has produced impressive clinical outcomes and has great potential to help thousands of otherwise terminal patients worldwide. In this review, we examine the state of the art of mechanical circulatory support: current practice, totally implantable systems of the future, evolving biventricular support mechanisms, the potential for myocardial recovery and adjunctive treatment methods, and miniaturized devices with expanded indications for therapy.Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 04/2014; 41(2):115-20. DOI:10.14503/THIJ-14-4143 · 0.63 Impact Factor
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ABSTRACT: Purpose of review Permanent long-term mechanical circulatory support (MCS) is currently reserved for patients who are transplant ineligible. In light of improved outcomes with current continuous flow devices, increased interest has focused on the potential extension of MCS therapy to ambulatory advanced heart failure patients and as an alternative to cardiac transplantation. Recent findings Average 1-year and 2-year survival with heart transplantation is about 85 and 80%, and with MCS therapy, it is 85 and 70% (with censoring at transplant). Specific subsets of destination therapy patients enjoy survival out to 2 years, which is comparable with transplant survival. Risk factor analyses identify similar risk profiles for each therapy. Life satisfaction after each is highly dependent on the frequency and severity of adverse events, which are quite different for these interventions. Patients with long expected waiting times will likely be the initial group for triage off the transplant wait list to MCS therapy. Summary MCS has progressively improved and may become a reasonable alternative to transplantation for highly selected patients with long expected waiting time. More routine extension of MCS therapy to the transplant population awaits further reduction of major adverse events, miniaturized devices, and less invasive implant techniques.Current Opinion in Organ Transplantation 10/2014; 19(5):486-93. DOI:10.1097/MOT.0000000000000120 · 2.38 Impact Factor