Dialysis Access Procedures

Hemodialysis is one of the main modalities for renal replacement therapy in patients with end-stage renal disease. Successful hemodialysis is contingent upon the creation of proper vascular access. Chronic vascular access was first established in 1960 by Scribner and colleagues when they created a shunt between the radial artery and the cephalic vein using an external Silastic device. However, this device was fraught with problems such as bleeding, clotting, and infection. In 1966, Breschia and Cimino described a surgical fistula between the radial artery and the cephalic vein just proximal to the wrist, thereby eliminating the external shunt and enabling a high flow system for hemodialysis. To this day, it remains the procedure of choice for patients with end-stage renal disease in need of chronic hemodialysis.

Several principles should be followed when planning vascular access surgery. In general,primary fistulas are better than prosthetic grafts due to better long-term patency and lower risk of infection and thrombosis. The upper extremity is preferable to the lower extremity and the nondominant arm should be employed first. If possible, a distal site should be selected first, preserving the upper arm for subsequent use. Careful pre-operative vascular assessment is performed with palpation of the radial, ulnar, and brachial pulses; an Allen's test is performed on both sides. The superficial veins of the arm should be carefully assessed with application of a proximal tourniquet. In some cases, the cephalic vein is readily evident at the wrist, antecubital fossa area, or in the lateral aspect of the upper arm. Once a decision has been made to perform access surgery, no venipunctures or blood pressure monitoring should be performed in that arm. If no superficial veins are apparent, the venous system may be assessed by ultrasound examination of the arm. Both the cephalic and basilic systems are interrogated, as well as the deep venous system and the central veins. Patients with suspected central venous stenosis or prior catheters inserted on the ipsilateral side, or with abnormal findings on ultrasound, may be assessed by conventional venography. If central stenoses are found, they should be corrected by endovascular techniques preoperatively, or an alternate site for access should be sought.