RESUMO
Magnification of the surgical field is considered an essential technique for performing accurate surgery on small caliber arteries. For this reason, we use the transmicroscopic technique of vascular surgery on the tibial arteries. We obtained good results in long term patency. Our experience and results in bypass grafting to the tibial artery using a microscope are reported. Forty-four tibial artery bypasses using transmicroscopic techniques were performed in 38 consecutive patients between June 1984 and December 1992. Twenty-seven patients had arteriosclerosis obliterans, 5 had thromboangitis obliterans, 5 had acute arterial occlusion and 1 had traumatic vascular injury. Patient ages ranged from 37 to 78 years old. Thirty-five were men and 3 were women. Twenty-six surgeries were performed for limb threatening and 14 were for disabling claudication. All patients were examined with conventional aortic lower extremity angiography preoperatively. The reversed saphenous vein was used in 38, in-situ saphenous vein in 3 and composite vein to vein graft in 2. All distal anastomoses were performed by the transmicroscopic technique. Continuous sutures were used for recipient vessels larger than 1.0mm in diameter. However interrupted 8-0 sutures were chosen for smaller vessels. Distal anastomosis was made at the proximal portion of the tibial artery in 24 cases, while the distal portion of the tibial artery was used in 20 cases. On preoperative angiography, the condition of the tibial arteries affected the patency rate when runoff was poor or fair. Nine cases were judged to have “poor” runoff. Three of these became occluded during the early postoperative period, and 1 during the late phase. Eight cases were judged to have “fair” runoff. One of these became occluded during the early postoperative period, and 3 during the late phase. There were no graft failures identified throughout the follow-up period in patients with good runoff. Cumulative patency rates were 86.2% after 1 year, 79.0% after 5 years, and 67.7% after 8 years, respectively. The patency rate of the 24 grafts in which distal anastomosis was performed on the proximal tibial artery was 71. 4% after 5 years. The patency rate of the 20 grafts on the distal tibial artery was 93.3% after 5 years. There was no significant difference observed in the patency of these two groups. Hospital mortality was 2.6%. Femorotibial bypass using transmicroscopic technique could save severely ischemic limbs while maintaining hospital mortality at a low level and reducing limb loss. The advantage of microscopic surgery is achieving fine observation because the magnification level is changeable, depending on the field needed. In anastomosis of small caliber vessels like the tibial artery, magnification by 10 times is important to observe the characteristics of the intima of the recipient artery. Subsequently, the procedure is performed by transmicroscopic techniques under magnification by 5 times, which provides much higher accuracy for suture than surgical loupe. High magnification prevents intraoperative technical error and unexpected injury.
RESUMO
Three patients with subclavian artery obstruction caused by arteriosclerosis underwent surgical reconstruction based on their specific anatomic characteristics. Subclavian artery transposition was performed in a patient with a short segmental occlusion of the proximal subclavian artery. The patient with a long segmental occlusion, from the origin of the internal thoracic artery to the origin of the thoracoacrominal artery, underwent bypass-grafting between common carotid artery and axillary artery. The graft was passed lateral to the anatomical tract to prevent compression by the scalenus and subclavian muscles. Because the branchial plexus also can be compressed in the thoracic outlet, the scalenus muscles were detached at the first rib in both methods. It is important to consider the specific cause of subclavian artery occlusion when planning corrective surgery. Ischemic and neurologic symptoms improved using both techniques.