The radiocephalic fistula is a very good configuration because it requires minimal dissection and provides a very reliable access that is free of complications for multiple years. The disadvantage of this configuration is a relatively greater risk of primary failure and interventions required to promote maturation, especially in elderly, female, and diabetic patients [25, 26]. Nevertheless, it is worth the attempt in young and pre-dialysis patients even in equivocal cases because even if it fails, it does not affect the creation of a secondary access at more proximal sites. Although some studies have demonstrated little association between the vessel size and the likelihood of fistula maturation [27], most centers require a minimum arterial diameter of 2 mm and a minimum venous diameter of 2.5–3 mm [28]. When diameter of the vein is less than 2 mm, only 16 % of fistula matured compared to 76 % when the diameter is greater than 2.5 mm [29].

When the cephalic vein in the forearm is not suitable for a fistula (or there is a failed forearm radiocephalic fistula), vein mapping or physical examination should measure the caliber of the basilic vein in the forearm as the next potential conduit. Although the basic vein needs to be transposed and requires more dissection, the primary and secondary patency rates of AVF from the basilic vein (54.7 and 76.7 %) are comparable to that of the cephalic vein (49.3 and 71.3 %) [30]. The rate of maturation failure is between 20 and 24 % [31, 32]. When the radial artery is greater than 2.5 mm and basilic vein diameter is greater than 3.5 mm, the cumulative patency of radio-basilic fistula is 93 % after 1 year, 78 % after 2 years, and 55 % after 3 years. Utilizing the basilic vein in the forearm helps preserving the proximal veins of the upper arm for future access which is essential in the younger patient population.

When neither the cephalic nor the basilic vein in the forearm is a good option, and the cephalic vein in the upper arm is available, a dilemma exists between a forearm AVG or an upper arm AVF as the next best alternative. Brachiocephalic AVFs have a maturation rate as high as 90 % [33]. As a matter of fact, in order to maintain a high fistula creation rate without increasing catheter-dependent time, some surgeons favored brachiocephalic fistula over forearm fistula unless a patient’s anatomy is ideal for a radiocephalic fistula [33, 34]. This approach is especially sensible in elderly patients where site preservation for future accesses is not as relevant as for the younger patients. Whereas only 26 % of patients with forearm fistulas were able to avoid CVC with initiation of dialysis, 43 % of patients with upper arm fistulas were able to do so because of better maturation rate and shorter maturation time [35].

Although brachiocephalic AVFs have a high success rate and respectable long-term patency, the risk of complication such as arterial steal is not insignificant [36, 37].As a result, using the proximal radial artery instead of the brachial artery as the source of inflow was suggested as a better alternative. The proximal radial artery has larger caliber and is generally less calcified/diseased than the radial artery at the wrist level; therefore, it should provide adequate arterial inflow and at the same time lower the risk of arterial steal syndrome with brachial artery fistulas. The long-term patency of proximal radiocephalic AVF could be as high as 80 % at 42 months with no ischemic complications [38]. There are several reported configurations for proximal forearm fistula construction such as side-to-side anastomosis between the proximal radial artery and median antebrachial vein or end-to-side anastomosis between the medial antecubital vein and the proximal radial artery [39] (Fig. 11.5). The mean time to maturation of the radio-median cubital vein or radiocephalic AVF at the elbow was 26 ± 5.2 days [39]. Failure rate was as low as 2.5 % with similar patency to brachiocephalic AVFs. Furthermore, using the median cubital vein allows arterialization of both the cephalic and basilic veins for venous outflow [39]. Another reason that makes the proximal radiocephalic AVF an attractive alternative is the delay of the need to proceed to a more proximal location while still preserving the option for future placement of a brachiocephalic fistula [40].

Although the KDOQI guideline recommended brachiocephalic AVF before forearm AVG, there is currently no randomized controlled trial comparing the outcomes of these two types of access. The configurations of the forearm AVG could be either straight or loop dependent on the sources of arterial inflow. If the radial pulse is palpable and has good quality, a straight forearm AVG from the radial artery to the antecubital vein is a good option. A retrospective study by Lee and associates reported that for patients with previously failed forearm AVFs, upper arm AVFs had higher failure rate than forearm AVGs (44 vs. 20 %), required more interventions for maturation and longer catheter dependence (131 vs. 34 days), and had more episodes of CVC-associated bacteremia (1.3 vs. 0.4 per patient) [41]. Survival was better for AVF when primary failures were excluded but similar when primary failures were included [41]. As expected, AVFs were only more advantageous over the AVGs once they became functional, due to less required intervention to maintain patency. Proponents of “forearm AVG first” also emphasize that the presence of a forearm AVF could promote dilation of the upper arm veins to allow a future construction of a brachiocephalic AVF once the forearm AVG fails [42]. As a matter of fact, forearm AVGs have been used as a “bridging” strategy to allow earlier cannulation and avoid CVCs for patients with late referral for long-term access placement, with the understanding that an AVF will be placed in the future upon the impending failure of the AVG. Nevertheless, in order for this “bridging” strategy to work, the venous anastomosis of the AVG should not cross the elbow, and repeated angioplasties or thrombolysis to salvage the AVGs should be avoided to prevent damaging the outflow veins.

When the cephalic vein in the entire arm is no longer available for a fistula conduit, the next viable option is either a forearm AVG or a brachiobasilic-transposition fistula (BBAVF). Although a BBAVF has the advantage of less complication such as infection and thrombosis (a 1-year patency of 69 % [43]), this configuration should not be an automatic first choice for every patient because of higher perioperative morbidity such as arm swelling, pain, bleeding, and higher steal than other fistula. In contrast, a forearm AVG is technically easier to construct, requires less time to cannulation, and has higher success rate after reintervention. When a BBAVF was compared to forearm loop AVGs (PTFE) in a randomized controlled trial for patients with no options for radiocephalic or brachiocephalic AVF, Keuter and associates reported significantly better patency and fewer interventions in the BBAVF group compared with the PTFE group and concluded that BBAVF is the preferred choice for vascular access [44]. However, although another randomized controlled trial by Morosetti and associates also confirmed superior long-term outcomes of BBAVF over forearm AVGs, they required longer hospital admission time, total intervention time, and mean interval to maturation. The authors concluded that BBAVF should be reserved for patients with good life expectancy but AVGs should be used for patients with compromised clinical conditions [45] such as vein diameter of less than 3 mm [46], elderly patients especially women with diabetes due to twofold higher risk of non-maturation for every decade increase in age [47, 48].

Finally, if there is no superficial vein available, the general guidelines recommend a forearm loop graft first for site preservation before placing a brachial-axillary AVG. The potential venous outflow sites for forearm AVGs are the median antecubital vein, the cephalic vein, and the basilic vein at the elbow. For upper arm AVGs, the cephalic and basilic veins as well as the deep veins (brachial and axillary) can be used [49]. Although the larger caliber of the venous outflow of the brachial-axillary AVG would suggest better outcomes than forearm AVGs, there is no evidence confirming this assumption. Indeed, the patency of forearm AVGs is similar to that of upper arm AVGs [49]. Therefore, unless the venous outflow at the level of the elbow is suboptimal, forearm AVGs should be attempted first before proceeding to the brachial-axillary configuration.