Experimental micro-anastomosis of 0.4-0.5 mm vessels.

Ninety-two anastomoses of arteries 0.5 mm in diameter have been performed in rats with an 85-90 per cent patency rate in the second postoperative week. The factors of prime importance in the achievement of high patency rates have been atraumatic handing and meticulous suturing technique. At 1 hour and at 8 to 10 days the patency rates were not statistically different whether 20 per cent magnesium sulphate heparin or normal saline were used. Similar results were obtained with 40 repairs of divided veins averaging 0.4 mm in diameter. These results suggest strongly that clinical microvascular surgery in vessels approximately 0.5 mm in diameter, especially in children, should given results comparable to 1 mm vessel surgery.