Transformation of superficial veins to thick-walled vein segments carrying high blood flow supplied by arterial blood is the basic idea behind creation of an arteriovenous fistula (AVF) for hemodialysis.¹ The vein should be easy to access and allow dual puncture with some intervening distance to avoid recirculation during hemodialysis. Shunt volume should be sufficient to allow dialysis flows with at least 250 mL/min. This requires shunt flows through the AVF of at least 300 mL/min. There are several considerations regarding vein selection when planning the surgery, during the procedure, and after surgery for long-term maintenance of the hemodialysis access.

In the upper extremity, the cephalic vein extending from the wrist to the deltoideo-pectoral fossa or the basilic vein from the wrist to the axillary fossa with its interconnecting vein at the midcubital region, as well as the deep brachial vein can be used as an access for hemodialysis.² Although the cephalic and midcubital veins are easily accessible for puncture, the forearm basilic vein is found on the dorsal aspect of the forearm, making puncture difficult and dialysis uncomfortable for the patient (Figure 36-1). In their anatomical positions, the upper arm basilic vein and the brachial vein are usually inaccessible to puncture without surgical adjuncts.³ Regarding anatomical considerations, the cephalic and midcubital veins should be used as first access option, and all other veins of the upper extremity should be used thereafter.^2,3

Both the greater saphenous vein and the superficial femoral vein may be used for creation of an AVF for hemodialysis.^3,4 The latter should be used only in redo procedures or in desperate redo situations. The saphenous vein may be used either as a transposed straight graft with a single anastomosis to the popliteal artery or as a subcutaneous loop graft anastomosed to the femoral artery. The superficial femoral vein may be used either as a free graft or as a straight graft transposed into the subcutaneous position.⁴

Clinical inspection with the use of a tourniquet allows adequate judgement of vein size, patency, and postphlebitic scarring in about 50% of cases. However, in some patients, the superficial veins are difficult to judge, such as because of their anatomic position, in obese subjects, in children, in the lower extremity, and in redo surgery. Preoperative vein mapping is helpful under these circumstances.⁵ When deep veins are used for AVF creation, preoperative vein mapping is mandatory. This can be done using either preoperative color duplex scanning or venography. Preoperative duplex scanning is performed with and without a tourniquet to judge for patency of the vein (without a tourniquet) and maximum vein diameter (with a tourniquet). The course of the vein should be marked on the skin before surgery. If duplex scanning is not readily available before surgery, venography can yield equally good information for planning the procedure (Figure 36-2).

There are several possibilities for preconditioning insufficient veins for later use in hemodialysis. Physical exercise with the hand in addition to the use of an upper arm tourniquet will allow considerable increase of size in borderline veins.⁶ If the patient is unable to perform these exercises or the deep veins have to be used, a staged procedure can be performed creating the AVF first and transposing the preconditioned vein in a second procedure thereafter.⁷

Because many patients start their initial hemodialysis with central venous catheters or have the history of central line placement or cardiac pacemakers, there will be a considerable number of central vein stenoses in patients undergoing AV access surgery. It is difficult to predict in most cases of central vein stenosis if the venous collateralization is sufficient for drainage after creation of an AVF. Usually, distal AVFs have little effect with regard to venous hypertension. On the other hand, subclavian vein stenosis or occlusion is associated with swelling of the arm after creation of an upper arm AVF in most cases.

Only a small portion of the vein is usually exposed for creation of an AVF. Known or suspected pathology of the vein central to the anastomotic site may therefore be easily hidden to the surgeon, especially if no preoperative vein mapping has been performed. Thrombosis at the intended site of anastomosis because of recent puncture is not an uncommon finding (Figure 36-3). Intraoperative dilatation of the vein with saline irrigation may add some information on vein quality and runoff but is not reliable and requires operator experience. Intraoperative vein angioscopy may be helpful (Figure 36-4) and allows detection of a variety of pathologic findings, but it is not readily available in most centers.⁸ Areas of endoluminal webbing or short postphlebitic stenoses may be reopened with an endovascular probe, but these areas are at high risk for early restenosis. If the vein central to the anastomotic site seems to be compromised, a different vein or a more proximal anastomotic site should be chosen rather than proceeding with the initial operative plan.