Ultrasound-Guided Limited-Access External Neurolysis With Hydroexpansion for Saphenous Nerve Scar Tethering After Varicose Vein Ligation: A Technical Report

Persistent saphenous neuropathy after venous surgery may be associated with focal scar tethering.We describe ultrasound-guided limited-access external neurolysis with hydroexpansion in a 66-year-old woman with right medial distal-leg and ankle sensory loss after varicose vein ligation.Ultrasonography showed focal fascicular enlargement and scar-directed nerve tenting.Six weekly hydrodissection procedures, each using 20 mL of 5% dextrose in water (D5W), produced no appreciable sensory improvement.Injection was associated with marked tactile resistance and severe pain; firm scar tethering and focal nerve angulation persisted despite extraneural fluid spread.After a two-year interruption of follow-up, the patient returned with persistent symptoms.Following proximal saphenous nerve blockade, 30 mL of D5W was used to expand a separable plane superficial to the nerve.Curved mosquito forceps were introduced through a 10mm incision for ultrasound-guided blunt external neurolysis.Post-release ultrasonography showed a straightened longitudinal nerve course, and the operator observed improved relative nerve mobility.The wound had healed, and sutures were removed at two weeks.At three weeks, the patient reported sensation at approximately 80% of the contralateral side, with two noncontiguous areas of residual hypoesthesia.The sensory estimate was based on subjective bedside comparison.This report describes the use of hydroexpansion to facilitate instrument access when injection alone did not separate a focal scar attachment.This single-patient technical report, with only three weeks of follow-up and subjective sensory assessment, provides low-level evidence limited to technical feasibility and cannot establish causality, efficacy, comparative benefit, or durability.