Ultrasound-guided cryoablation of genitofemoral nerve for chronic inguinal pain.

BACKGROUND

Cryotechnology is a modality of renewed interest in pain management. It is safe and effective when used to treat neuropathies of sensory and mixed nerves. Cryoablation, in general, is devoid of the risk of neuroma formation and can provide several weeks to months of adequate pain relief. Traditionally, cryoablation was applied blindly to the target area. The use of ultrasound guidance may improve the efficacy and reduce morbidity. We report a case of a successful cryoablation of the femoral component of the genitofemoral nerve using ultrasound guidance in a patient with chronic inguinal pain. A 47 year-old male (ASA Classification II for obesity, HLD, and OSA, 125kg, 69 in) presented to the Walter Reed Pain Clinic with the complaint of 4/10 VAS left sided groin pain of 3 month duration. The patient was diagnosed with a neuropathy of the femoral component of the left genitofemoral nerve. He received a diagnostic block with local anesthetic and reported immediate pain relief that lasted one week. The patient was counseled on the risks and benefits of cryoablation. The skin was anesthetized with 1% lidocaine and a 14 gauge angiocatheter needle was introduced using an in-plane technique to the target area. A Westco Cryoablation machine (San Diego, California) with a 14 gauge Lloyd Neurostat cryoprobe was then passed via the angiocatheter. The area was treated for two 3-minute intervals while the cryo probe was visualized under ultrasound. Ultrasound is increasingly utilized for both acute and chronic pain procedures. Ultrasound offered several advantages in this case. It allowed a smaller gauge introducer and cryoablation probe to be used since there was better visualization of the target area. Ultrasound helped identify important vascular structures, allowing safe introduction of the introducer and cryoablation probe. The patient remains pain free at 2-month follow-up.