Compliance effects on small diameter polyurethane graft patency
Journal
Journal of Biomedical Materials Research
Journal Volume
27
Journal Issue
10
Pages
1269-1279
Date Issued
1993
Author(s)
Abstract
Microporous compliance matched and noncompliant grafts were compared in a dog carotid artery interposition model. We fabricated 4 mm diameter sponge type polyurethane (Biomer) tubes 5 cm in length with a 0.5 mm wall thickness. The luminal surface was covered with a 50 μm coating of cross‐linked gelatin. Compliance was measured in vitro and in vivo by volume and vessel diameter changes. Over a mean arterial pressure range of 55–155 mm Hg, the diameter changes of grafts and stump arteries were measured in situ using an ultrasonic Hokanson device. Compliance matched grafts were found to have the same in vitro compliance values as the natural canine carotid at a mean arterial pressure of 100 mm Hg. Compliance matched and noncompliant grafts had values of 10.3 ± 1.3 and 0.9 ± 0.1 × 10−2 mm Hg, respectively. End to end arterial anastomoses were constructed between the graft and the host arteries. The use of synthetic grafts with matched compliance to the adjacent natural vessels has been advocated as the ideal solution to circumvent the problems of graft failure. These studies indicate that compliance values for compliance matched grafts decreased immediately after implantation (from 10.3 to 6.5 × 10−2 %/mm Hg) and within 6 weeks decreased to 3.6 × 10−2 %/mm Hg. The compliance values for noncompliant grafts remained constant throughout the test period. At autopsy all grafts showed a tightly adhered tissue capsule. The thickness of the anastomotic hyperplasia at the distal sites of compliance matched grafts was significantly different (P < .05) than that of the adjacent artery. The patency for compliant and noncompliant grafts was 64% and 50%, respectively. Evidence for polyurethane graft degradation was obtained by Fourier transform infrared spectroscopy and gel permeation chromatography analysis of patent explants. Compliance mismatch alone does not contribute to graft failure, however, material degradation, suture technique and/or capsule formation can play a contributory role although these were not tested directly. © 1993 John Wiley & Sons, Inc. Copyright © 1993 John Wiley & Sons, Inc.
Other Subjects
Cardiovascular system; Chromatographic analysis; Degradation; Fourier transforms; Gel permeation chromatography; Graft vs. host reactions; Implants (surgical); Infrared spectroscopy; Polyurethanes; Anastomotic hyperplasia; Arterial anastomoses; Autopsy; Capsule formation; Carotid artery; Compliance effects; Compliance matching; Polyurethane graft patency; Suture technique; Grafts; gelatin; polyurethan; animal experiment; animal tissue; artery compliance; artery diameter; artery intima proliferation; carotid artery; conference paper; controlled study; degradation; dog; end to end anastomosis; gel permeation chromatography; graft patency; histology; infrared spectroscopy; mean arterial pressure; nonhuman; suturing method; Animal; Biocompatible Materials; Blood Pressure; Blood Vessel Prosthesis; Carotid Arteries; Dogs; Elasticity; Gelatin; Glutaral; Microscopy, Electron, Scanning; Muscle, Smooth, Vascular; Polyurethanes; Regression Analysis; Spectroscopy, Fourier Transform Infrared; Support, U.S. Gov't, P.H.S.; Time Factors
Type
journal article