Ligation of vessels in surgical treatment of aneurysms was applied in 97.5% of cases during World War II. Operations in cases of aneurysms with ligation of large vessels often result in necrosis of the extremity or in its reduced function, which is accounted for by insufficient blood supply. Between 1950 and 1955 we operated on 43 patients with various aneurysms of the trunk vessels, and in every case the continuity of the vessels was restored by means of a mechanical vascular suture applied by the vessel-suturing apparatus. When operating for aneurysms, one is bound to encounter great technical difficulties caused by considerable adhesions between the aneurysmatic sac and the surrounding tissues. Sometimes the aneurysmatic sac and vessels are calcified in the region of the pathological anastomosis, and for this reason the operation of restoring the continuity of the vessels becomes impossible. The anatomical position of the aneurysm may likewise impede