The Annals of Thoracic Surgery, Vol 46, 278-282, Copyright © 1988 by The Society of Thoracic Surgeons
Experimental repair of ventricular septal defects using autologous right ventricular muscle flaps: preliminary report
SR Gundry, TR Coughlin Jr, NH Goldberg, JR Hankins, CF Mackenzie, J Flowers, R Moorman and JS McLaughlin
Department of Surgery, University of Maryland School of Medicine, Baltimore 21201.
Survival after repair of postinfarction ventricular septal defects remains
poor, often due to extensive loss of contractile muscle in the septum or
left ventricle. We evaluated whether a contractile flap of right
ventricular muscle could be used to repair a similar ventricular septal
defect to augment left ventricular performance in 7 fully instrumented
mongrel dogs (weight, 23 to 28 kg). By using hypothermic bypass and cold
fibrillatory arrest, a trapezoidal right ventricle flap was fashioned from
the free wall of the mid to lower right ventricle, basing its widest
portion anteriorly on the septum and left ventricle. A large, 2-cm-diameter
core of septum was excised beneath this flap to simulate a postinfarct
ventricular septal defect. The right ventricular flap was then invaginated
through the defect and sewn to the left ventricular side of the septum with
pledgeted sutures taken full thickness through the flap and septum in a
"vest-over-pants" fashion. Contraction of the right ventricular flap was
confirmed visually and by postbypass multiple gated acquisition scans. The
right ventricular defect was closed with fascia lata. All dogs were weaned
from bypass without inotropes. Precardiac and postcardiac outputs of 2.5
+/- 0.5 versus 2.3 +/- 0.4 L/min and left ventricular end-diastolic
pressures of 4 +/- 2 versus 4 +/- 3 mm Hg were identical. No shunts were
detected by oxygen saturation. Autopsies confirmed the integrity of the
repair. We conclude that septal defects can be repaired by using
contractile right ventricular muscle, thus preserving left ventricular
function. This technique offers promise for repair of postinfarction
ventricular septal defects by using autologous, already conditioned to
contract, cardiac muscle, but its application in humans must await
long-term testing.