Types of AV fistula: radiocephalic, brachiocephalic, brachiobasilic and AV grafts

A hemodialysis arteriovenous fistula (AVF) can be created at the wrist, at the elbow or in the upper arm, using the patient's own vein or a synthetic graft. Each type matures at its own pace, has its own typical complications and is cannulated differently. This guide covers the types of AV access, how to recognize them on exam and on ultrasound, and what changes for the person holding the needle.

For professionals · Updated November 13, 2026 · 11-minute read

What an AV fistula is, and why there are several types

An AVF is a surgical connection between an artery and a vein. Arterial blood flows into the vein, which "arterializes": it dilates, its wall thickens and its flow rises until it can take two needles and the flow that dialysis needs. Brescia and Cimino described it in 1966, joining the radial artery and the cephalic vein at the wrist [4]. It is still the reference access.

Each AVF is named after the vessels it joins: artery first, then vein. In English and in Latin America the upper-arm artery is the brachial artery; Spanish guidelines call it humeral, so a brachiocephalic AVF is the same as a humerocephalic one, and brachiobasilic is the same as humerobasilic.

Which type is created depends mostly on each person's vessels. Before surgery, arteries and veins are mapped with ultrasound (see vein mapping before AV fistula surgery). As a reference, the European ESVS guideline considers a minimum diameter of 2 mm adequate for forearm fistulas and 3 mm for upper-arm fistulas [3]. Age, diabetes, the dominant arm, previous accesses and how long the person is expected to stay on hemodialysis also count [1].

The types of AV access at a glance

1. Radiocephalic AVF (Brescia-Cimino)

It joins the radial artery to the cephalic vein at the wrist, usually with the end of the vein sewn to the side of the artery (end-to-side anastomosis). An even more distal variant is created in the anatomical snuffbox, at the base of the thumb. If the wrist is not suitable, it can be created higher up the forearm before moving to the elbow.

It is the classic first choice because it leaves the whole arm free for future accesses. Its weak point is maturation. Between 28% and 53% of fistulas do not mature enough to be used, according to the series collected by the Spanish GEMAV guideline [2], and forearm fistulas with small or calcified vessels fail most often. Assess it at 4–6 weeks and do not cannulate it before 2 weeks [2]. The criteria are in the guide to the rule of 6s and fistula maturation.

• Where to cannulate: the forearm cephalic vein, on a straight segment away from the anastomosis. GEMAV asks for at least 2.5 cm from the anastomosis and between needle tips [2].
• Typical problems:
  • stenosis near the anastomosis, the most common reason a fistula does not mature;
  • accessory veins that steal flow;
  • tortuous segments;
  • over the years, aneurysms from always cannulating the same area (see AV fistula aneurysm).
• On ultrasound: the radial artery dilates and its waveform becomes low-resistance. Access flow (Qa) is still measured in the brachial artery (see AV fistula Doppler ultrasound).

2. Brachiocephalic AVF

It joins the brachial artery to the cephalic vein at the elbow, sometimes through the median or the perforating vein. The upper-arm cephalic vein dilates as it runs up the anterolateral side of the arm to the shoulder.

It is the usual option when the wrist is not suitable. It carries more flow and matures better than a radiocephalic fistula. In exchange, because it arises from the brachial artery, it has a higher risk of hand ischemia from steal and of high flow [3]. Its typical stenosis appears in the cephalic arch, where the vein joins the axillary vein near the shoulder [5].

• Where to cannulate: the upper-arm cephalic vein, which usually offers a long segment for site rotation.
• Practical problem: in people with obesity the vein can lie more than 6 mm below the skin. It is hard to palpate, needs a steeper angle and a longer needle, and may need surgical superficialization [2,5]. This is where ultrasound-guided cannulation helps most (see difficult fistula cannulation).
• What to watch: the brachial artery and the median nerve lie medially, toward the inner side of the arm. Keep the tip visible and do not drift toward them.

3. Transposed or superficialized brachiobasilic AVF

It joins the brachial artery to the basilic vein at the elbow. The upper-arm basilic vein has a good diameter and is usually well preserved because, running deep, it escapes blood draws. The drawback is its position: under the fascia of the inner arm, next to the brachial artery and the median nerve. To make it cannulable, the surgeon transposes it, lifting it out of its bed into a tunnel under the skin. Another option is to superficialize it: raise it where it lies. This is done in one or two stages.

It is the native option when there is no usable cephalic vein and, as a native access, it is usually preferred over a graft [2,3]. The surgery is longer, leaves a scar along the arm, and the fistula takes longer before it can be used. Like the brachiocephalic fistula, it arises from the brachial artery and is also associated with steal and high flow [3].

• Where to cannulate: along the tunnel, on the front and inner side of the arm. Have the course mapped, because it does not always follow the scar.
• What to watch: the transposed vein runs over the brachial artery and the median nerve. Going too deep or too steep can pass through the vein and reach the artery or the nerve. Ultrasound keeps depth under control.

4. AV graft (prosthetic access)

When there are no suitable veins, a synthetic tube, almost always expanded polytetrafluoroethylene (PTFE), is placed between an artery and a vein. The most common configurations are:

• forearm loop: one limb leaves the brachial artery, runs down the forearm, turns and returns to an elbow vein;
• straight forearm graft, or an upper-arm graft, straight or curved, from the brachial artery to the axillary vein;
• thigh graft, when there are no options left in the arms.

Its big advantage is time. GEMAV allows cannulation from week 2 to 4, and early-cannulation grafts can be used much sooner [2]. For people expected to be on hemodialysis for a short time, KDOQI 2019 considers a graft a reasonable option [1]. In exchange, grafts develop stenosis more often, especially at the venous anastomosis from intimal hyperplasia. They also thrombose and get infected more often, and need more interventions to stay open [2,5].

• How to cannulate:
  • no tourniquet, because a rigid tube does not dilate;
  • at an angle of about 45°;
  • rotating sites along the whole graft;
  • 5 cm or more from the anastomoses [2].
  See the details in the guide to AVF needle angle, gauge and spacing.
• Flow direction: in a loop graft you need to know which limb is arterial and which is venous. The venous needle goes in the venous limb, in the direction of flow. Check it with the operative diagram, by palpation or with color Doppler.
• On ultrasound: the graft wall gives an echogenic double contour ("railroad track") and a uniform lumen of about 6 mm [5].

5. Endovascular AVF (endoAVF)

This is the newest option of the last decade. Instead of an incision, the fistula is created through the skin, with catheters or with an ultrasound-guided needle. An artery in the proximal forearm (radial or ulnar) is connected to an adjacent deep or perforating vein. Flow rises through the perforating vein into the superficial veins of the elbow and upper arm, which are the ones you cannulate. In the NEAT trial, with 80 patients at 9 centers, the fistula was created successfully in 98% of cases [6].

For the person cannulating, the key point is that there is no "textbook" vein. Depending on the case, the cephalic, the basilic or the median vein matures, sometimes several of them. Check with ultrasound which vein carries the flow and draw its course before the first cannulations.

How the type of access is chosen

For years the rule was "fistula first", with a fixed order. The 2006 KDOQI guidelines, cited by the Spanish GEMAV guideline, put the radiocephalic fistula first and the brachiocephalic second [2]; the transposed brachiobasilic fistula or a graft came after that. The KDOQI 2019 update replaces that order with an ESKD Life-Plan. It is an individual plan that takes into account anatomy, other conditions, life expectancy, the person's preferences and the accesses they will need in the future [1]. In practice, most teams follow these principles:

• Distal to proximal: starting at the wrist preserves the elbow and upper arm [2,7].
• Non-dominant arm first, if the vessels allow it [2,7].
• Native before prosthetic, unless the person's situation calls for something else [1,2].
• On time: plan access creation when eGFR falls below 15 mL/min/1.73 m² or dialysis is expected within about 6 months [7]. That leaves time for maturation and avoids starting on a catheter.

What changes when you cannulate each type

Before cannulating any access, look, feel and listen along its whole course (step by step in the guide to AVF cannulation technique). If you do not know the access, ask for the operative diagram or scan it: in an unfamiliar access it is easy to mistake the arterial limb for the venous one, or the usable vein for a collateral.

Educational content. It does not replace supervised hands-on training or your unit's protocols.

References

1. Lok CE, Huber TS, Lee T, Shenoy S, et al. KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update. Am J Kidney Dis. 2020;75(4 Suppl 2):S1-S164. doi.org
2. Ibeas J, Roca-Tey R, Vallespín J, Moreno T, et al. Spanish Clinical Guidelines on Vascular Access for Haemodialysis (GEMAV). Nefrología. 2017;37(Suppl 1):1-191. doi.org
3. Schmidli J, Widmer MK, Basile C, de Donato G, Gallieni M, et al. Vascular Access: 2018 Clinical Practice Guidelines of the European Society for Vascular Surgery (ESVS). Eur J Vasc Endovasc Surg. 2018;55(6):757-818. doi.org
4. Brescia MJ, Cimino JE, Appel K, Hurwich BJ. Chronic hemodialysis using venipuncture and a surgically created arteriovenous fistula. N Engl J Med. 1966;275(20):1089-1092. doi.org
5. Sharbidre KG, Alexander LF, Varma RK, et al. Hemodialysis access: US for preprocedural mapping and evaluation of maturity and access dysfunction. RadioGraphics. 2024;44(1):e230053. doi.org
6. Lok CE, Rajan DK, Clement J, et al. Endovascular proximal forearm arteriovenous fistula for hemodialysis access: results of the prospective, multicenter Novel Endovascular Access Trial (NEAT). Am J Kidney Dis. 2017;70(4):486-497. doi.org
7. Ayala Strub MA, Manzano Grossi MS, Ligero Ramos JM. Fístulas arteriovenosas para hemodiálisis [Arteriovenous fistulas for hemodialysis; in Spanish]. Nefrología al día. nefrologiaaldia.org