abdominal aorta-renal bypass

Abdominal aorta-renal artery bypass is the earliest application for the treatment of renal vascular hypertension, and it is also the most widely used procedure for a variety of renal artery stenosis. Since the application of this surgical technique in the 1950s, Poutasse (1955), DeBakey (1956), and Morris (1960) have summarized more than 100 experiences in their respective reports in less than 10 years. In 1962, China's Xiong Yucheng et al. also reported the successful experience of this type of surgery for the first time. In the future, this operation has been carried out in various places, and has become the first choice for the treatment of renal vascular hypertension. The transplanted blood vessels include Dacron (Polyester), Gortex, and silk-spun blood vessels specially made in China. Although this kind of substitute is convenient to take, it is easy to form thrombus in the later stage, and the rate of re-obstruction in long-term follow-up is quite high. Especially for transplants with small diameters. Gortex may work better. Spinning blood vessels are used only in a small number of patients in China, and clinical experience is not yet abundant. Autologous saphenous vein grafting was performed by Kunlin in 1949 for vascular occlusive disease of the lower extremity, and was soon used for grafting autologous tissue of renal artery stenosis. It is considered that the endometrium does not contain thrombotic substances (tissue rejection). Therefore, it is widely used, but it also has its own weaknesses. After long-term impact of arterial pressure, the intima can proliferate, the lumen of the lumen is aneurysm-like expansion, and the graft segment is long and distorted, resulting in narrow anastomotic stoma on both sides. In the 1970s, Stanley, Fry et al reported that the incidence of expansion and stenosis was 16%. There have also been branches with a great saphenous vein to repair the renal artery trunk and the first-stage branch stenosis, with fewer cases applied. Autologous arterial grafting has been the preferred method in recent years (Lye, 1975), which has the advantages of the first two grafts without the disadvantages of autologous vein grafting. Especially for children with renal vascular hypertension, since the use of autologous arterial grafting technology, the success rate of renal artery reconstruction is significantly improved, and the rate of nephrectomy is relatively reduced. The splenic artery was first used in aortic and renal artery bypass grafting. In atherosclerosis, the splenic artery is rarely involved, and the diameter is similar. For example, the blood flow of 150 ml per minute is not damaged, and the length is removed, and the blood supply to the spleen is not affected. Others such as the internal iliac artery and the hepatic artery can also be used for free transplantation without ischemic damage to the supplied organs. Treatment of diseases: renal aneurysms Indication The indications for abdominal and aortic-renal artery bypass are extremely extensive. Any renal artery obstructive hypertension (such as renal arteriovenous fistula, aneurysm) that does not require resection of renal artery disease can be considered. For the first time, other renal artery reconstruction surgery or percutaneous transluminal angioplasty (PTA), such as reoperation, is used. However, stenotic lesions must be confined to the renal artery trunk. Such as lesion invasion and branching, this procedure should not be implemented. Contraindications 1. The heart and brain suffer from serious complications or serious complications due to long-term hypertension. 2. The arteritis disease is still in the active development period, and the cause is not controlled. 3. The lesion is extensively invaded by the renal artery trunk and branches, or the trunk has been completely blocked. 4. There are a wide range of thrombosis in the branches of the renal parenchyma or after the stenosis. 5. Urinary toxicosis and water and electrolyte disorders have occurred after bilateral renal artery stenosis. Should treat uremia, anemia, correct electrolyte abnormalities, until the general condition is improved, before surgery can be performed. Preoperative preparation Prepare routinely before surgery. Surgical procedure 1. Incision and exposure After entering the abdominal cavity through the midline or the midline, the abdominal artery is exposed between the renal artery and its plane below the inferior mesenteric artery. The renal artery lesions were explored to reveal the stenosis and the distal renal artery. The diameter of the tube is determined to determine which graft to use. If the diameter is 8 to 10 mm, Dacron is ideal, and atherosclerotic plaque is most commonly used. Muscle fibrosis often has no stenosis and dilatation, and it is better to use autologous saphenous vein or internal iliac artery or splenic artery transplantation. 2. Side-end anastomosis of renal artery and graft The U-shaped arterial clamp was used to clamp the narrow and distal renal artery, and one side of the incision was made on the lower edge. The whole layer was sutured by 5-0 silk thread or nylon thread. After the anastomosis was completed, the heparin cold physiology was injected through the open end of the graft tube. Brine, after inflation, determine the length required for anastomosis with the aorta and check for leaks at the anastomosis. 3. The graft is anastomosed to the aorta If the anastomosis is confirmed to be good, the renal artery clamp is released, the graft port is clamped, and the opening is trimmed into a slope. A portion of the aorta was clamped with an aortic clamp, and a pair of equal incisions were made at the corresponding portions of the sides to align the graft orifice with the abdominal aorta. Some authors have cut off the distal segment of the renal artery stenosis and end-to-end anastomosis with the graft, which is considered to be more conducive to renal hemodynamics. This method is commonly used when the main artery of the renal artery is thick, bypassing the graft vessel and placing it behind the renal vein. 4. Autologous vascular grafting If the renal artery in the posterior segment of the stenosis is thin, between 5 and 6 mm, or when the first-stage branch is involved, autologous transplantation of the autologous saphenous vein or internal iliac artery is often used. The saphenous vein and its branches were exposed by a straight incision in the upper thigh and groin, and the length was 10 cm, and the diameter was about 4 to 6 mm (adult). If the branch needs an anastomosis, it is cut along with the entire saphenous vein branch and has surrounding fat to protect the outer membrane from damage. The excised blood vessels are bathed in cold Ringer's solution or heparinized blood. The proximal end or the associated branch is anastomosed to the end or end of the main artery or branch of the renal artery, and the distal end of the distal aorta is anastomosed with the abdominal aorta. Its technical points are the same as those of Dacron transplantation. If you want to use the abdominal artery aorta-renal artery bypass surgery, the most common is the internal iliac artery or splenic artery. The diameters of the two arteries are similar to those of the renal arteries, and the blood supply to the organs supplied after cutting is not affected, and branches can be transplanted. When the left renal artery is operated, it is more convenient to expose and cut the splenic artery, and the spleen artery is rarely involved in atherosclerosis. The use of arterial vessels for transplantation, anastomotic surgery techniques are also easier to implement and reliable. The near and long-term effects are also better than other types of implants. The surgical technique is the same as the application of venous blood vessels and Dacron. complication 1. The most serious complication after surgery is acute renal failure. Because of the above various bypass surgery, it is mostly performed on one side, and the contralateral kidney is mostly normal. Therefore, acute tubular necrosis in the surgical side of the kidney is not easy to be found. If bilateral renal artery bypass grafting is performed at the same time, the operation and renal ischemia time are longer, the incidence of such complications is higher, the risk is greater, and it is more appropriate to advocate the behavior of bilateral lesions. Bilateral acute renal failure occurred after unilateral surgery, mostly caused by long operation time, hemorrhage, long time of hypotension, and severe hypovolemia. Hemodialysis should be treated through the anuria period. 2. After the cholesterol embolus of the aortic wall falls off, it can be transferred to other organs to cause embolism. It should pay attention to the function of other organs and the skin color change of the limbs. 3. If a large saphenous vein graft or Dacron transplant is used, renal angiography should be performed during long-term follow-up. Because of the common aneurysm-like dilation of the former, the latter is prone to embolism, and blood pressure and surgical side renal function should be observed regularly. Autologous arterial transplantation is not easy to occur in the above sequelae, so the long-term effect is satisfactory, only for general follow-up.