Abstract
Late failure of PHUV often results from anastomotic pannus hyperplasia. Varying factors have been implicated in the process. In this paper, we studied the influence of compliance mismatch (C. M.) at anastomotic sites and use-fulness of the phonoangiography (PAG) and frequency analysis to evaluate the ideal anastomotic geometry. Compliance, C is defined by V/V0·Δp×100, (Δp=100; pressure from 50 to 150mmHg), therefore C=V/V0. It is noted that umbilical vessels and knitted Dacron are about 8 times less compliant than that of the thoracic aorta of dog whereas woven Dacron and EPTFE are about 50 times less compliant. In order to evaluate the influence of C. M. on the anastomotic site, we studied the diameter change in the area under pressure range of 50mmHg to 150mmHg. That is, the diameter of the anastomotic area was measured from X-ray film taken in the pressure range using mercury as a contrast medium. We have concluded that, 1) the compliance of the suture line depends on graft compliance, 2) the region affected on the C. M. is host artery within 5mm from suture line, and 3) stenosis at the anastomotic site and disproportion of graft diameter amplify the influence of the C. M. In order to alleviate the C. M., we are studing the fixation of the host vessel wall near the suture line using Teflon ring. We also studied PAG and its frequency analysis of anastomotic bruits under controlled graft flow. The data showed that abnormality of the anastomotic geometry is proportional to the bruits and inversely proportional to flow, therefore its quantitative evaluation is possible by means of determining the maximal graft flow at the level, at which the anastomotic bruits disappear from the bruits frequency spectrum.
