Cryopreserved venous homografts as vascular conduits in canine carotid arteries

In this study we evaluated the histologic condition, prostacyclin production, and compliance of morphologically intact cryopreserved venous homografts (CVH) and autografts 3, 6, and 9 months after arterial implantation. Eighteen external jugular veins were cryopreserved and implanted into the carotid arteries of mongrel dogs. All grafts were patent at the time of excision. Electron microscopy documented a disrupted endothelium in the homografts at 3 months that was intact at 9 months. The cellular infiltrate, suggestive of rejection, in the 3-month homografts resolved by 9 months. Prostacyclin production at 3 months was 8.7 +/- 3.2 pg/ml/cm2 compared with 24.1 +/- 9.6 pg/ml/cm2 (p less than 0.025) in the adjacent carotid artery. The prostacyclin production in the 6-month homografts was 21.7 +/- 12.4 pg/ml/cm2, not significantly different from the adjacent carotid artery. The return of prostacyclin paralleled the return of an intact endothelium. Compliance of fresh vein was diminished by cryopreservation, from 1.57 +/- 0.39% radial change/mm Hg (10(-2] to 0.79 +/- 0.21% radial change/mg Hg (10(-2] (p less than 0.02). The compliance of CVH at 3 months (1.7 +/- 1.0) and at 6 months (1.1 +/- 0.42) was not significantly different from cryopreserved veins. These data showed that CVH remained patent in dogs for 9 months, without loss of compliance for 6 months, and developed a morphologically intact and functional endothelium that paralleled the resolution of the inflammatory infiltrate.