[Surgical management of dysfunctions of dialysis fistulas]

Due to the superficial position of shunt vessels we do not use complicated equipment or diagnostic procedures in the morphological assessment of shunt insufficiency or shunt occlusion. Preoperatively, we merely conduct a clinical examination including inspection, pulse, palpation of the shunt veins and arteries with and without venous congestion, and shunt auscultation. Subsequently, we reoperate the shunt under local anesthesia, at which time the anastomosis is usually checked and repositioned. From January 1995 to May 1996, 539 shunt operations were performed in 371 patients, whereby 263 of these were reoperations. The reoperations were performed due to shunt occlusion (n = 144), shunt stenoses (n = 60), shunt aneurysms (n = 17), steal syndrome (n = 3), and rare complications such as hematoma, shunt infection, seroma, and other disturbances (n = 6) (32 patients were treated in other clinics after reoperation or the functional disturbance of the shunt was not recorded). Angiography was only conducted if the clinical examination did not provide enough information about the shunt problems, and so, preoperatively, only six angiographic examinations were conducted (stenosis, n = 3; aneurysm, n = 1; steal syndrome, n = 2). All reoperations, with only few exceptions (PTFE shunt), were conducted under local anesthesia. At reoperation, 184 new proximal shunts were made, 14 thrombectomies conducted, seven PTFE fistulas made, 13 shunts positioned on the opposite side, five shunts ligated, and eight various other operations performed (32 patients were given further treatment elsewhere or no treatment records were available). If during reoperation flow disturbances were suspected (arterial stenosis) or the blood was flowing towards center (proximal venous stenosis) angiography was performed intraoperatively to assess the condition of the vessels. The 4% rate of early occlusion using this procedure was very low. Only 21 patients had to have more than two reoperations. After 2 years 65% of the reoperated AV fistulas were still functional. Without further diagnostic procedures, we performed immediate, outpatient reoperation under local anesthesia, preferably positioning new proximal shunts so that dialysis could be conducted immediately using the existing dialysis shunt. Only if there were particularly complex functional shunt disturbances (steal syndrome, proximal venous flow disturbance, or arterial stenosis) did we employ other diagnostic procedures (angiography, DSA). With this approach the functional shunt disturbances could be eliminated quickly and effectively, which also minimized the cost and stress for the patient.