title: Heparin reduces the intimal hyperplasia seen in microvascular vein grafts.
abstract: The influence of heparin on microvascular vein graft intimal hyperplasia was studied in a rat model. The iliolumbar vein was grafted into the iliac artery in 80 rats. Heparin was delivered via a subcutaneous miniosmotic pump, starting either 2 days before grafting (early heparin group, n = 20) or immediately after grafting (heparin group, n = 30). Saline-containing pumps were placed in the control group (n = 30). Heparin activity was measured at 24 h, and again 3 weeks later when the animals were sacrificed. The grafts were harvested and prepared for histological examination. The intimal thickness was measured at the anastomoses and in the mid-graft region using an eye-piece graticule set at right angles to the graft internal elastic lamina. Heparin significantly reduced the intimal thickness at the anastomoses, from a median of 38 microns (range: 10-100 microns) in the control group to a median of 20 microns (range: 10-150 microns) in the heparin group. A similar reduction was seen in the mid-graft region. Although intimal thickening was reduced in the early heparin group, this reduction failed to reach statistical significance. The possible clinical application is discussed.
authors.affiliation: University Department of Surgery, Queen Elizabeth II Medical Centre, Nedlands, Western Australia.
authors.forename: P E
authors.initials: PE
authors.lastname: Norman
authors.forename: A K
authors.initials: AK
authors.lastname: House
mesh_terms: D000714:Anastomosis, Surgical; D000818:Animals; D001807:Blood Vessel Prosthesis; D004730:Endothelium, Vascular / Q000187:drug effects; D006083:Graft Occlusion, Vascular / Q000517:prevention & control*; D006493:Heparin / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D006965:Hyperplasia / Q000517:prevention & control; D007083:Iliac Artery / Q000601:surgery; D007866:Leg / Q000098:blood supply*; D008833:Microcirculation / Q000601:surgery; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D051381:Rats; D011920:Rats, Inbred WF; D014680:Veins / Q000473:pathology / Q000637:transplantation
chemical_list: D006493:Heparin