The Synergy Pocket Circulatory Assist device from Circulite, a company out of Saddle Brook, New Jersey and Aachen, Germany, is doing well in a European clinical trial, according to the MIT Tech Review.
According to the magazine, the device, first covered by us in Aug 2007, has been implanted in nine patients, all of them still alive and apparently doing well. Of these patients, five have successfully gone on to heart transplants, showing the device to be a potentially useful modality as a bridge to transplantation.
A quick refresher on the technology:
… the Synergy Pocket Circulatory Assist device combines a superficially positioned micro-pump with inflow and outflow cannulae placed with endovascular techniques. Blood is drawn from the Left Atrium via the Inflow Cannula that is connected to the micro-pump which pumps the blood back to the body via the Outflow Graft to the Subclavian Artery…
The Synergy Pocket Circulatory Assist device works in synergy with the patient’s native heart function and pumps up to 3 liters of blood per minute (partial circulatory assist) to increase the total cardiac output (blood to body).
The hemodynamic effects of partial circulatory assist were assessed in a computer-based heart failure simulation model which predicts partial circulatory assist of 2 to 3 liter of blood flow per minute:
Decreases left ventricular end diastolic pressure by 7 to 10 mm Hg Provides significant pressure and volume unloading of the native heart Increases net cardiac output by ~ 1 liter of blood flow per minute
The hemodynamic effects of partial circulatory assist have also been reported in a small, single center study. Twenty patients supported on HeartMate™ VE Ventricular Assist Device (VAD), were assessed on full assist (approximately 5 liters of blood flow per minute) and partial assist (approximately 1.6 liters of blood flow per minute) which was achieved by reducing the device’s cycles per minutes setting. The authors concluded that partial circulatory assist:
Improved peak VO2 consumption Improved myocardial function
…Synergy device micro-pump has been refined to be the smallest implantable blood pump and has several unique features that are designed to minimize the risk of thrombus formation and hemolysis.
The Synergy device micro-pump combines axial, centrifugal and orthogonal flow paths with a single-stage impeller that is powered by an integrated brushless micro-electric motor. The micro-pump is the size of a AA battery with an outer body diameter of 14 mm, length of 49 mm, weight of 25 grams and pumps up to 3 liters of blood per minute.
The Synergy device micro-pump design features a unique magnetically and hydrodynamically levitated and stabilized impeller design. The design allows the motor to be sealed thus eliminating blood contact in the motor and the potential of thrombosis formation. The micro-pump also features a proprietary self-washing flow path that minimizes the risk of thrombus formation in or around the impeller.