Venous Patch Aortoplasty for Correction of Experimental Coarctation

Abstract

Experimental chronic aortic coarctation in eight beagle dogs was repaired with a free autogenous vein patch graft. Seven sham-operated dogs were controls. One year later the aortic resting blood pressure proximal to the aortoplasty was 122/77 (SD 10/8) mmHg in the aortoplasty group and 112/76 (SD 11/10) in the control group. The strength of the venous patch was tested with intravenous infusion of phenylephrine 0.01 mg/kg/min for 10 min (total dose 0.1 mg/kg). The aortic blood pressure after this infusion was 240/167 (38/26) and 271/179 (27/19) mmHg, respectively. The systolic gradient across the aortoplasty site was 3.9 (6.9) mmHg at rest and 7.7 (16.6) after the phenylephrine infusion. The aortic cross-sectional area at the aortoplasty site was 46.8 (2.7) mm² in the aortoplasty group and 43.7 (3.7) in the control group. Focal intimal smooth muscle cell hyperplasia was found in the venous patch and in the aortic wall beside the sutures, and the medial layer of the patch was fibrotic. A venous patch may be an option for treatment of coarctation.

Key Words:

• aortoplasty
• coarctation
• histology
• phenylephrine
• venous patch