Interventional radiology in hemodyalysis fistulae and grafts
Background. The aim of the paper is to review the role of interventional radiology in the management of haemodialysis vascular access. The evaluation of patients with haemodialysis vascular access is complex. It includes the radiology/ultrasound evaluation of the peripheral veins of the upper extremities with venous mapping and the evaluation of the central vein prior to the access placement and radiological detection and treatment of the stenosis and thrombosis in misfunctional dialysis fistulas. Preoperative screening enables the identification of a suitable vessel to create a haemodynamically-sound dialysis fistula. Clinical and radiological detection of the haemodynamically significant stenosis or occlusion demands fistulography and endovascular treatment. Endovascular prophylactic dilatation of stenosis greater than 50% with associated clinical abnormalities such as flow-rate reduction is warranted to prolong access patency. The technical success rates are over 90% for dilatation. One-year primary patency rate in forearm fistula is 51%, versus graft 40%. Stents are placed only in selected cases; routinely in central vein after dilatation, in ruptured vein and elastic recoil.
Conclusions. Thrombosed fistula and grafts can be declotted by purely mechanical methods or in combination with a lytic drug. The success rate of the technique is 89-90%. Primary patency rate is 8% to 26% per year and secondary 75% per year.