Spontaneous anastomosis of transected vessels

Experiments were performed on rats to establish the capacity for spontaneous repair of transected arteries and veins. The tests were done on the femoral vessels, with transection effected in a number of modifications. Veins proved capable of bridging even a triple transection within 2 weeks. Not a single artery, however, anastomosed. Vascular repair was on the basis of adventitial and perivascular networks. Explanations of arterial incapacity for spontaneous repair can presently be only speculative. The observations add to our knowledge concerning the revascularization of free grafts, and also indicate that in veins, spontaneous anastomosis can be induced by loosely approximating the stumps.