Distal radial artery cannulation in the Hegu (LI4) region for perioperative invasive arterial blood pressure monitoring: two case reports.

BACKGROUND: Invasive arterial blood pressure monitoring is essential for perioperative hemodynamic management. While proximal radial artery cannulation is widely used due to its ease and low complication rate, it is unsuitable for patients with upper-limb trauma, wrist/forearm surgery, local soft-tissue injury, or prior vascular injury from puncture. Distal radial artery access at the Hegu (LI4) region-originally developed for cardiovascular procedures-offers a viable alternative: it lies superficially, is less affected by wrist motion, and benefits from collateral perfusion via the ulnar artery and palmar arches. CASE PRESENTATION: Two patients required alternative arterial access due to limited conventional proximal radial artery access. Case 1: a 41-year-old woman after emergency right upper-limb replantation for traumatic amputation. Case 2: a 50-year-old man after debridement, internal fixation, and free anterolateral thigh flap reconstruction for a severe right-hand crush injury. In both, the left distal radial artery (Hegu region) was used for invasive arterial pressure monitoring. Under local anesthesia and ultrasound-guided out-of-plane puncture, a 20-gauge arterial catheter was successfully placed on the first attempt (puncture-to-placement time: 25-30 s). Catheters remained in place for 24-48 h. Waveforms were clear, stable, and unaffected by wrist motion. Invasive pressures matched non-invasive measurements at concurrent time points-though formal agreement analysis was not performed. After removal, puncture sites healed without complications (no bleeding, hematoma, infection, nerve injury, radial artery occlusion, or hand ischemia). One patient reported mild soreness (VAS = 1). CONCLUSION: Distal radial artery cannulation in the Hegu region may be a feasible and well-tolerated alternative for perioperative invasive arterial pressure monitoring when conventional proximal radial artery access is unavailable or undesirable. Potential advantages include a puncture site away from the wrist joint, stable catheter fixation, good patient tolerance, and preserved collateral circulation.