Ultrasound-guided blockade of the lateral femoral cutaneous nerve: technical description and review of 10 cases

Abstract

Blockade of the lateral femoral cutaneous nerve (LFCN) is performed for therapeutic management of meralgia paresthetica and as a regional anesthetic technique. The conventional technique is associated with high failure rates secondary to variable LFCN anatomy. We describe a technique for blockade of the LFCN using ultrasound guidance. A cross-sectional view of the LFCN was obtained by identifying the anterior superior iliac spine, then moving a 14-to-7MHz linear array ultrasound probe in a medial caudal direction until the nerve was encountered. The needle was advanced to the LFCN under ultrasound guidance via a lateral to medial approach. Injection using dynamic ultrasound demonstrated excellent perineural spread. Ten subjects underwent successful blockade of the LFCN with this technique. Five subjects were obese. Use of ultrasound for precise needle placement allowed low injection volumes to be utilized. Theref were no complications. Ultrasound guidance can facilitate blockade of the LFCN for diagnostic and therapeutic purposes and may be particularly beneficial with patients with challenging surface anatomic landmarks, or when low volume injections are desired.