Can the radial or ulnar arteries be steered to improve hand perfusion, and what medical management is appropriate for inadequate hand blood flow?

Arterial Steering for Hand Perfusion: Surgical and Medical Management

Yes, arterial steering procedures can effectively improve hand blood flow, with radial artery transposition being the most established surgical technique for high-flow situations, while endovascular embolization combined with angioplasty offers a less invasive alternative for specific anatomic scenarios. 1, 2

Surgical Arterial Steering Options

Radial Artery Transposition (RUDI Procedure)

• The Revision Using Distal Inflow (RUDI) procedure is specifically recommended for patients with pathologic high flow (>2 L/min) in brachial artery-based arteriovenous fistulas causing hand ischemia or cardiac symptoms. 1
• This technique involves replacing the brachial artery inflow with transposed distal radial artery, achieving a mean flow reduction of 66% ± 14%. 2
• Technical success rates reach 91%, with clinical success in 75% of symptomatic patients. 2
• Secondary patency rates are 89% ± 5% at one year and 70% ± 8% at three years. 2
• All four patients with hand ischemia in the reported series achieved complete resolution without recurrence. 2

Endovascular Arterial Steering

• Embolization of the distal radial artery combined with ulnar artery angioplasty can restore adequate hand perfusion by leveraging the robust collateral network between radial and ulnar systems. 1
• This approach is particularly effective when arterial stenosis contributes to distal ischemia, as 62% of patients referred for steal syndrome have hemodynamically significant (>50%) arterial stenosis. 3

Critical Diagnostic Prerequisites

Mandatory Arteriography

• Complete diagnostic arteriography from the aortic arch to the palmar arch is foundational before determining any management strategy. 3
• Digital subtraction angiography (DSA) must be performed both with and without occlusion of the AV access to detect proximal arterial lesions. 3
• Failure to recognize concomitant arterial stenoses may prove detrimental post-surgery, potentially causing access thrombosis if banding procedures are performed in the presence of proximal stenosis. 3

Physical Examination Essentials

• Palpate both radial and ulnar pulses at the wrist on the flexor surface (radial pulse lateral, ulnar pulse medial). 1, 4
• Assess for digital ulceration or necrosis, hand temperature, and capillary refill. 1
• Evaluate for return of radial or ulnar pulses with manual compression of the graft to confirm diagnosis. 3

Anatomic Considerations for Arterial Steering

Collateral Circulation Robustness

• The hand possesses extraordinarily robust collateral circulation between radial and ulnar systems, making ischemic complications from single-vessel occlusion extremely rare. 4
• The radial artery becomes dominant in the distal forearm and constitutes the major source of vascularization to the hand, despite the ulnar artery being dominant at the elbow. 5
• Even with radial artery occlusion rates of 0.8-3.0% following procedures, hand ischemia remains extraordinarily rare due to ulnar artery collateralization. 4

When Single Artery Ligation is Safe

• In the absence of acute hand ischemia, ligation of a lacerated radial or ulnar artery is safe and cost-effective. 6
• No patient with single forearm arterial injury without associated major trauma develops an ischemic hand. 6
• The remaining intact artery demonstrates a consistent increase in flow velocity to compensate. 6

Medical Management Options

Staging-Based Urgency Assessment

• Stage I (pale/blue and/or cold hand without pain): Monitor closely, optimize medical therapy. 1
• Stage II (pain during exercise and/or hemodialysis): Consider intervention if lifestyle-limiting after medical optimization. 1
• Stage III (pain at rest): Urgent intervention required. 1
• Stage IV (ulcers/necrosis/gangrene): Immediate intervention mandatory—do not delay, as rapid deterioration leads to gangrene. 1

Pharmacologic Therapy

• Iloprost IV can be used for severe peripheral ischemia: Start at 0.5 ng/kg/minute, titrate every 30 minutes up to 2 ng/kg/minute based on tolerability. 7
• Administer as 6-hour daily infusion through peripheral line or PICC using infusion pump with 0.22- or 0.2-micron in-line filter. 7
• For patients with moderate or severe hepatic impairment (Child-Pugh Class B or C), initiate at 0.25 ng/kg/minute. 7

Guideline-Directed Medical Therapy

• Revascularization should only be considered for lifestyle-limiting claudication after inadequate response to guideline-directed medical therapy and structured exercise therapy. 1
• Endovascular procedures should not be performed solely to prevent progression to critical limb ischemia. 1

Critical Pitfalls to Avoid

• Never perform arterial steering procedures without complete arteriography from aortic arch to palmar arch—concomitant arterial stenosis proximal to the arterial anastomosis can cause catastrophic access thrombosis if unrecognized. 3
• Do not delay intervention for fingertip necroses—rapid final deterioration leads to gangrene requiring early intervention. 1
• Do not assume radial artery dominance without assessment—while the radial artery is typically dominant distally, individual anatomic variation exists. 4, 5
• Avoid confusing hand pain with true ischemia in dialysis patients—pain may be due to carpal tunnel compression, tissue acidosis, or venous hypertension rather than arterial insufficiency. 1