Postoperative disc entrapment following cardiac valve replacement--a report of ten cases.

The sudden jamming of a prosthetic valve disc is one cause for postoperative hemodynamic deterioration. This complication occurred in 10 instances (2% of disc valves implanted), resulting in 4 fatalities. In 6 patients the disc entrapment was a complication following mitral valve replacement, and in 4 others the malfunction followed aortic valve surgery. The entrapment of the disc occurred on the second postoperative day in 3 patients. Two of these were due to an unresected chordal strand becoming wedged between the disc and valve rim of a Björk-Shiley mitral prosthesis and resulted in death. In the third patient, the aortic valve disc became attached to the Björk-Shiley composite aortic graft following the repair of an aortic dissection. A firm blood clot had formed between the graft and the oversewn aortic wall. This patient recovered after cardiopulmonary resuscitation and subsequent reoperation. The remaining cases developed while the patients were still either on the operating table or in the recovery room. The mechanisms of the disc entrapments are presented and the significance of an early correct diagnosis and urgent surgical correction is underlined.