Technical Considerations

The hemodialysis patient population, often advanced in age, suffers from serious systemic disease and multiple comorbidities. Tissues are often fragile, arteries may be calcified or diseased, and surgical wounds may heal slowly or poorly. Therefore, meticulous technique, use of fine instruments, and gentle tissue handling are essential to avoid complications. Care must be taken to avoid cautery or retraction trauma to nearby sensorimotor nerves. Minimizing vessel manipulation can reduce vasospasm of artery or vein.

End-to-side or side-to-side AV anastomosis may be performed, depending on the ability to mobilize the vein in question and the need to preserve multiple (retrograde) venous outflow paths. Surface venous anatomy varies considerably, particularly near the antecubital fossa; adjustment in placement of the skin incision or use of draining venous side branches may be necessary. Anastomosis diameter, relative to size of inflow artery and outflow vein, may be a factor in achieving adequate arterial inflow for fistula dilation or in the development of “arterial steal” from the hand circulation. Subcutaneous tunneling of prosthetic graft material must be deep enough to allow puncture site sealing, but not so deep to be undetectable for cannulation. Attention to hemostasis and layered coverage of underlying vascular anastomosis or prosthetic graft material will protect against wound complications and graft infection.

Preoperative Vessel Mapping by Duplex Ultrasound

Standard vessel-mapping protocols provide important information regarding approach to the best AVF or AVG location. Cephalic vein diameter is shown in Figure 35-1, A. Venous fibrosis, identified by thickened vein walls or incomplete compressibility, may predict poor distensibility with arterial inflow. Thrombosis from venipuncture or IV placement is shown in gray-scale imaging (Fig. 35-1, B). The basilic vein often lies deep and medial in the arm and will need superficialization if used for AVF (Fig. 35-1, C). A small or heavily calcified radial artery at the wrist, a common finding in diabetic patients, may contraindicate use of this artery for inflow (Fig. 35-1, D).