New burst test method for comparing strengths of blood vessel repairs

An in vivo system was developed which allows researchers to determine the intraluminal pressures necessary to burst anastomosed blood vessels. Rat femoral arteries underwent standard microsurgical anastomoses and sham surgeries. After 6 min of leak-free blood flow, the vessels were ligated and cannulated with PE 50 tubing. The catheter was tied into position with 6-0 suture, constructing a water-tight balloon of tissue inclusive of the repair site around the tubing, then attached via a "Y" adapter to a pressure transducer with a digital readout and to a saline filled syringe in an infusion pump. The digital readout from the transducer accurately expressed the pressure on the anastomosis. The highest pressure recorded when the anastomosis ruptured was taken to be the anastomotic burst pressure. Mean burst pressure for 9 suture anastomoses was 326 mm mercury. All vessel burst pressures exceeded rat mean systolic pressure; 90% exceeded rat maximum systolic pressure. All sham surgeries failed to burst, even at pressures exceeding 1,500 mm Hg. The burst pressure test clearly provides researchers with a valid quantitative measure for in vivo comparison of the efficacies of various anastomotic techniques.