We evaluated the short- and mid-term in vivo performance of the Innovamedica ventricular assist device (VAD), a new, low-cost, paracorporeal, pneumatically actuated, pulsatile blood pump. We implanted the VAD in six healthy sheep by inserting the stainless-steel inflow cannula into the left ventricular apex and suturing the outflow graft to the descending thoracic aorta. The anesthetized animals were supported for 6 hours, and pump performance, hemodynamic parameters, and hemolysis were monitored. The pump maintained a blood flow of 4.4 ± 0.8 L/min and an arterial blood pressure of 76 ± 15 mm Hg. At 6 hours, the plasma free hemoglobin concentration was 5.11 ± 0.6 mg/dl (baseline value, 4.52 ± 0.7 mg/dl). The VAD was easy to implant and deair and performed well during the 6 hour period. After successful short-term results, we similarly implanted the VAD in two healthy sheep for 30 days. The animals reached the scheduled end point without device-related problems. Postmortem examination of the explanted organs revealed small infarcted areas in the kidneys of one animal, but renal function was unaffected; the animal also had two thrombi (3 and 7 mm) on the outlet valve. This device may offer a simple, economical alternative to currently available VADs.

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We evaluated the in vivo performance of the Innovamedica pneumatic ventricular assist device (VAD), a new prototype of a simple, low-cost device for hospital circulatory support programs. We implanted the Innovamedica VAD in 6 sheep (weighing 55 to 91 kg). The inflow cannula was placed in the left ventricle, and the outflow cannula was anastomosed to the descending thoracic aorta. After heparinization (3mg/kg), we initiated the pump and monitored its hemodynamic performance for 6 hours. In a subsequent study we implanted the device for left ventricular support in two sheep for a 30-day period. We evaluated device performance based on implantation procedure, hemodynamic performance, and hematological impact. We monitored hematological and biochemical variables, and we assessed hemolysis. In the short-term experiments, the pumps maintained a mean blood flow of 4.4 ± 0.8 L/min. During support, mean arterial blood pressure was 76 ± 15 mmHg. The overall average concentration of plasma free hemoglobin was 5.11 ± 0.6 mg/dl compared with a baseline value of 4.52 ± 0.7 mg/dl. In the 30 day trials, mean blood output was 4 l/min ± 0.2, plasma free hemoglobin was 5.9 ± 4 mg/dl for the 30 day period excluding the first 48 hours. Warfarin/Aspirin anticoagulation was used after the first 72 hours with an average INR of 2.9 for the entire test period. Post-mortem showed no blood clots or any significant tissue damage to brain, lungs or kidneys. The devices operated without any significant adverse events in all of the experiments. The Innovamedica VAD was easy to implant and de-air and was found to be effective, reliable and biocompatible.