Platelet aggregation on peritoneal tube grafts and double velour grafts in the inferior vena cava of the pig

In 14 pigs the infrarenal vena cava was replaced with a peritoneal tube graft or a collagen-coated double velour graft. With 111In-labelled platelets dynamic in vivo imaging of platelet aggregation over the graft was carried out using a scintillation camera. After removal, the grafts were examined by autoradiography for an evaluation of the platelet aggregation pattern. Measurements of activity in different regions of the grafts were also performed. The results indicated low activity uptakes both in vivo and in vitro. The dynamic study did not show any uniform increase of activity content 1-3 h postoperatively, in any of the groups. During the period 2-3 h postoperatively no increasing activity accumulation was found. Hemashield Microvel grafts had an uptake of 0.19 per cent of the total activity while the corresponding figure for peritoneal tube grafts was 0.17 per cent. The activity distribution on different parts of the grafts indicated lower accumulation on the Hemashield graft surfaces than in the anastomoses, while the accumulation was higher on the graft surface of peritoneal tube grafts. The autoradiographical findings supported this indication. In conclusion, low platelet aggregation was found with both dynamic in vivo imaging and in vitro activity measurements on both peritoneal tube grafts and collagen-coated double velour grafts.