Copulsation balloon for right ventricular assistance: Preliminary trials

Abstract

Background - Options for management of acute right ventricular (RV) failure are limited. This report describes preliminary testing of a temporary RV assist device that acts by direct compression of the RV. The system comprises a pancake-shaped silicone balloon (5 cm diameter) connected to a drive console that delivers a 65-mL pneumatic pulse during cardiac systole. Methods and Results - Initial in vivo tests were performed on 6 pigs (weight, 41±4 kg). RV wall motion and stroke volume were monitored via transesophageal echocardiography. Acute RV failure was created by graded right coronary ligation, which yielded a 63% reduction in RV stroke volume (39.9±8.2 to 14.7±1.9 mL; P<0.002). We secured the balloon over the RV free wall by attaching it to the edges of the opened pericardium. The sternum was then reapproximated, and data were collected with the device off and on (every beat). Device placement had no deleterious effect on RV function. Balloon activation returned RV stroke volumes to normal (37.8±9.2 mL) and increased mean pulmonary artery pressures from 13±2 to 16±3 mm Hg (P<0.01). RV compression did not induce or exacerbate tricuspid regurgitation. Mean aortic pressure improved from postinfarction levels but did not return to normal. Conclusions - We conclude that the pulmonary circulation can be supported in the short term via cardiac compression and that balloon copulsation techniques for short-term RV failure should be tested in long- term models.