Use of a counterpulsation balloon as a substitute for the pulmonic valve: a new application

An inflatable, 3-ml balloon positioned within the distal right ventricular outflow tract was used to restore pulmonic valve function in 8 dogs that had undergone open-chest valvectomy. Balloon inflation and deflation were accomplished with a counterpulsation console. Valvectomy produced loss of the pulmonic incisura, a decrease in pulmonary artery diastolic pressure (PADP; mean +/- standard error) (9.5 +/- 1.3 versus 4.4 +/- 0.6 mm Hg, p less than 0.01), and an increase in pulmonary artery pulse pressure (PAPP) (8.6 +/- 0.7 versus 19.1 +/- 1.9 mm Hg, p less than 0.01) without significantly affecting forward cardiac output (CO) (1,750 +/- 110 versus 1,880 +/- 230 ml/min, p is not significant). Properly timed counterpulsation restored the pulmonic incisura, raised the PADP from 6.1 +/- 0.8 to 9.5 +/- 0.8 mm Hg (p less than 0.01), lowered the PAPP from 15.1 +/- 1.4 to 10.6 +/- 1.0 mm Hg (p less than 0.01), and raised the forward CO from 1,850 +/- 260 to 1,920 +/- 260 ml/min (p less than 0.01). The injection of glass beads, 40 to 150 microns in diameter, into the right ventricular outflow tract increased pulmonary vascular resistance from 383 +/- 87 to 730 +/- 150 dyne . sec cm-5 (p less than 0.05) and decreased forward CO from 1,850 +/- 260 to 1,570 +/- 230 ml/min (p less than 0.05). Following this injection, counterpulsation again restored the pulmonic incisura, raised the PADP from 9.3 +/- 1.4 to 16.0 +/- 1.8 mm Hg (p less than 0.01), lowered the PAPP from 25.0 +/- 2.5 to 18.2 +/- 2.5 mm Hg (p less than 0.01), and raised the forward CO from 1,570 +/- 230 to 1,720 +/- 220 ml/min (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)