OPERATIVE MANAGEMENT OF FUNCTIONAL DISTURBANCES OF DIALYSIS FISTULAS

Due to the superficial position of shunt vessels we do not use complic ated equipment or diagnostic procedures in the morphological assessmen t 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, a nd shunt auscultation. Subsequently, we reoperate the shunt under loca l anesthesia, at which time the anastomosis is usually checked and rep ositioned. From January 1995 to May 1996, 539 shunt operations were pe rformed in 371 patients, whereby 263 of these were reoperations. The r eoperations were performed due to shunt occlusion (n = 144), shunt ste noses (n = 60), shunt aneurysms (n = 17), steal syndrome (n = 3), and rare complications such as hematoma, shunt infection, seroma, and othe r disturbances (n = 6) (32 patients were treated in other clinics afte r reoperation or the functional disturbance of the shunt was not recor ded). Angiography was only conducted if the clinical examination did n ot provide enough information about the shunt problems, and so, preope ratively, only six angiographic examinations were conducted (stenosis, n = 3; aneurysm, n = 1; steal syndrome, n = 2). All reoperations, wit h only few exceptions (PTFE shunt), were conducted under local anesthe sia. At reoperation, 184 new proximal shunts were made, 14 thrombectom ies conducted, seven PTFE fistulas made, 13 shunts positioned on the o pposite side, five shunts ligated, and eight various other operations performed (32 patients were given further treatment elsewhere or no tr eatment records were available). If during reoperation flow disturbanc es were suspected (arterial stenosis) or the blood was flowing towards center (proximal venous stenosis) angiography was performed intraoper atively to assess the condition of the vessels. The 4% rate of early o cclusion using this procedure was very low. Only 21 patients had to ha ve 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 ther e were particularly complex functional shunt disturbances (steal syndr ome, proximal venous flow disturbance, or arterial stenosis) did we em ploy other diagnostic procedures (angiography, DSA). With this approac h the functional shunt disturbances could be eliminated quickly and ef fectively, which also minimized the cost and stress for the patient.