Operative procedure and volumetry in experimental biomechanical hearts

To date, skeletal muscle ventricles (SMVs) have been integrated into the circulation by a second operation following construction, vascular delay and several weeks of electrical conditioning. Recently, intra-thoracic SMVs around a mock system contracted against a pressure of 70 mmHg for several months immediately after construction in the presence of clenbuterol. This indicates that the two-step procedure may be exchanged for a clinically favorable one-step operation. The stroke volume is tested intra-operatively.

In twelve Boer goats, the latissimus dorsi muscle was folded in a double layer around a polyurethane chamber, which was integrated into descending thoracic aorta. This muscular flow-through chamber containing a stabilizing inner layer denoted "Biomechanical Heart" (BMH) showed immediate activity against systemic pressure. The conductance catheter method was applied for analysis of intra-operative stroke volume.

The one-step operative procedure employed was practicable in all 12 goats. Operative complications were eliminated without difficulty. Intraoperative application of the conductance catheter resulted in BMH with a stroke volume of 55 +/- 14 ml. In the best BMH on postoperative day 132, a continuous pumping capacity of 1.4 l/min was measured. This BMH functioned up to day 414 postoperatively, and failed due to a rupture of the pumping chamber.

This operative procedure and dynamic volumetry of experimental Biomechanical Hearts might be relevant for clinical use.