Residency · Residency · General Surgery

Vascular Access for Hemodialysis

Introduction

Vascular access is the lifeline for patients with end-stage renal disease (ESRD) requiring hemodialysis. The general surgeon plays a critical role in creating and maintaining functional vascular access. The Kidney Disease Outcomes Quality Initiative (KDOQI) and the Fistula First Catheter Last initiative establish the hierarchy of access: arteriovenous fistula (AVF) is preferred over arteriovenous graft (AVG), which is preferred over tunneled dialysis catheter (TDC). Optimal access planning requires understanding of vascular anatomy, patient-specific factors, and the technical aspects of access creation.

Preoperative Assessment

Patients should be referred for access creation when the GFR falls below 25 mL/min/1.73m2 or within 1 year of anticipated dialysis start, as AVF requires 2-3 months for maturation. The history should address dominant hand, prior central venous catheters, pacemakers, prior access procedures, peripheral vascular disease, and heart failure status. Physical examination includes the Allen test to confirm dual arterial supply to the hand, assessment of arterial pulses at radial, ulnar, and brachial positions, venous assessment with tourniquet (evaluating visible cephalic and basilic veins, compressibility, and evidence of prior thrombosis), and assessment for collateral veins suggesting central venous stenosis on the chest wall and neck. Duplex ultrasound is the standard preoperative vein mapping study, with minimum vein diameter of 2.5 mm and arterial diameter of 2.0 mm for AVF creation. Central vein imaging with CT venogram or MR venogram is obtained if central stenosis is suspected based on history of central lines, pacemaker leads, or unilateral arm edema. Vessel preservation through education of patients and staff to avoid venipuncture and IV placement in the non-dominant arm is essential to preserve veins for future access.

<image>Anatomical diagram of the upper extremity venous and arterial system relevant to hemodialysis access, showing the cephalic vein, basilic vein, brachial artery, radial artery, and ulnar artery with labeled preferred sites for arteriovenous fistula creation from distal to proximal</image>

Arteriovenous Fistula (AVF)

Principles and Site Selection

The "Rule of 6s" for maturation requires minimum flow of 600 mL/min, vein diameter of at least 6 mm, depth of 6 mm or less from the skin surface, at least 6 cm of cannulation length, assessed at 6 weeks. The order of preference proceeds from distal to proximal, with the non-dominant arm used first. The radiocephalic (Brescia-Cimino) fistula at the wrist is the gold standard first access and has the longest patency but lower maturation rates of 50-60%. The brachiocephalic fistula at the antecubital fossa has a higher maturation rate of 70-80% and higher flow rates. The brachiobasilic fistula with transposition requires mobilization and superficialization of the basilic vein and is a good option when the cephalic vein is inadequate; a two-stage procedure is often preferred. Lower extremity AVF using the femoral artery to great saphenous vein is reserved for when upper extremity options are exhausted.

Surgical Technique

Anesthesia is typically local with sedation or regional block (brachial plexus block), and general anesthesia is rarely needed. The anastomosis is performed end of vein to side of artery with continuous 6-0 or 7-0 polypropylene suture and an arteriotomy length of 5-7 mm. Intraoperative assessment should confirm a palpable thrill over the anastomosis, as absence of thrill suggests a technical problem or poor inflow/outflow. Postoperative care includes avoiding blood pressure measurements and venipuncture in the access arm, daily thrill assessment, and arm elevation to reduce edema.

Maturation Failure and Interventions

Maturation failure occurs in 20-60% of AVFs and is defined as inability to use after 3-4 months. The most common cause is juxta-anastomotic stenosis, followed by accessory veins stealing flow, central venous stenosis, and inadequate inflow. Interventions include fistulogram with angioplasty of stenoses, accessory vein ligation, and surgical revision of the anastomosis.

Arteriovenous Graft (AVG)

Arteriovenous grafts are indicated when veins are inadequate for AVF creation, after failed AVF, or when access is urgent (AVG can be cannulated in 2-4 weeks with early-cannulation grafts). Expanded polytetrafluoroethylene (ePTFE) at 6 mm diameter is the most commonly used graft material. Configurations include forearm loop (brachial artery to antecubital vein), upper arm straight (brachial artery to axillary vein), and thigh loop (femoral artery to femoral vein). Primary patency is 50% at 1 year and 25% at 2 years, with secondary patency of 70% at 1 year with interventions. Complications include venous anastomotic stenosis (the most common cause of graft failure), thrombosis, infection, pseudoaneurysm, and steal syndrome.

<image>Surgical diagrams comparing arteriovenous fistula creation (end-vein-to-side-artery anastomosis at the wrist) with arteriovenous graft placement (forearm loop configuration with ePTFE graft), showing the anastomotic technique, direction of flow, and cannulation segments</image>

Tunneled Dialysis Catheters (TDC)

Tunneled dialysis catheters are indicated as a bridge to AVF or AVG maturation, for acute dialysis initiation, when no other access options exist, or when patient life expectancy is less than 1 year. The preferred insertion site is the right internal jugular vein because of its straightest path to the SVC-right atrial junction, and the subclavian vein should be avoided due to its high stenosis risk that compromises future access. The catheter tip should be positioned at the SVC-right atrial junction for optimal flow rates. Catheter types include dual-lumen cuffed catheters (such as Ash Split Cath and Palindrome), with the Dacron cuff anchored at 2 cm from the exit site. Catheter-related bloodstream infection occurs at a rate of 2-5 episodes per 1000 catheter-days, with the most common organisms being Staphylococcus aureus and coagulase-negative staphylococci; antibiotic lock solutions reduce infection rates. Central venous stenosis is particularly common with subclavian catheters (40-50% stenosis rate). Catheter malfunction from fibrin sheath formation or thrombosis is treated with tPA instillation or catheter exchange over a guidewire.

Complications of Vascular Access

Steal Syndrome (Access-Related Hand Ischemia)

Steal syndrome occurs in 1-5% of AVFs and 5-10% of AVGs, and is more common with proximal (brachial artery) access. It presents with pain, coolness, numbness, and weakness of the hand, and severe cases may progress to tissue loss. | Steal Grade | Symptoms | Treatment |

Classification ranges from Grade 1 (mild, no treatment needed) to Grade 2 (intermittent ischemia during dialysis) to Grade 3 (rest pain) to Grade 4 (tissue loss/gangrene). Treatment options include the DRIL procedure (Distal Revascularization-Interval Ligation), which is the gold standard and involves bypass from proximal to distal artery with ligation of the artery between the access and bypass origin. Banding or plication narrows the access to reduce flow. Proximalization of arterial inflow (PAI) converts distal inflow to a more proximal artery with a bypass graft. Access ligation is the last resort for refractory ischemia.

Other Complications

AVF infection is rare (less than 2%), while AVG infection occurs at a rate of 10-20%; treatment ranges from antibiotics alone for early cellulitis to complete graft excision for extensive infection. True aneurysms develop in AVFs from repeated cannulation and pseudoaneurysms in AVGs; these are treated with excision and interposition grafting or patch repair. High-output cardiac failure occurs with access flow exceeding 2 L/min and may require banding or access ligation. Venous hypertension causing ipsilateral arm swelling from central venous stenosis is treated with angioplasty, stenting, or access ligation.

<image>Illustration of the DRIL procedure for access-related steal syndrome showing the brachial artery, arteriovenous fistula, bypass graft from proximal brachial to distal brachial artery, and the point of interval ligation between the access anastomosis and the bypass origin</image>

Key Clinical Pearls

Planning for dialysis access should start early when GFR falls below 25, as AVF maturation takes 2-3 months minimum. Upper extremity veins must be preserved in all CKD patients by avoiding IVs, blood draws, and PICCs in the non-dominant arm. The AVF is the gold standard with the best long-term patency and lowest complication rates. The right internal jugular vein is the preferred site for tunneled dialysis catheters, and subclavian access should be avoided. Steal syndrome is more common with brachial artery-based access, and the DRIL procedure is the gold standard treatment.

References

1. Lok CE, Huber TS, Lee T, et al. KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update. Am J Kidney Dis. 2020;75(4 Suppl 2):S1-S164.
2. Huber TS, Carter JW, Carter RL, Seeger JM. Patency of autogenous and polytetrafluoroethylene upper extremity arteriovenous hemodialysis accesses: a systematic review. J Vasc Surg. 2003;38(5):1005-1011.
3. Schanzer H, Schwartz M, Harrington E, Haimov M. Treatment of ischemia due to "steal" by arteriovenous fistula with distal artery ligation and revascularization. J Vasc Surg. 1988;7(6):770-773.
4. Vascular Access Work Group. NKF KDOQI Guidelines: Clinical Practice Guidelines for Vascular Access. Am J Kidney Dis. 2006;48(Suppl 1):S176-S273.

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