Neurophysiological and ultrasound findings in sural nerve lesions following stripping of the small saphenous vein.

We describe the neurophysiological and ultrasound (US) findings in two patients with right sural nerve lesions following stripping of the small saphenous vein for varicose vein treatment. In the first case, US showed a tear of the nerve proximal to the lateral malleolus and a hypoechoic swelling of the proximal stump, likely related to a terminal bulb neuroma. A sural conduction study performed distally and proximally to the lesion through a near-nerve needle technique showed absent responses. In the second case, US showed a deep subcutaneous extension of a postsurgical scar placed behind the lateral malleolus close to the sural nerve, but no nerve discontinuity. Sural conduction study showed absent responses distal to the scar. Sural stimulation immediately above the scar yielded a small response at the sciatic nerve. A subsequent investigation performed 15 months after the operation showed absent proximal and distal responses. The combination of US and sural conduction study, including recording at the sciatic nerve, to our knowledge has not been described previously, and may yield important complementary information in the diagnosis of sural nerve lesions.