Presented at the 2013 AAPM Annual Meeting « Back

Saphenous Nerve Cryo-Ablation

Monika A. Krzyzek, DO, monika.krzyzek@us.army.mil¹, Robert H. Overbaugh, MD², Prasad Lakshminarasimhiah, MD¹, Kevin Guthmiller, MD⁴, Karl A. Lautenschlager, MD⁵, Brandon J Goff, DO³, (1) San Antonio Military Medical Center, San Antonio, Texas, (2) Brooke Army Medical Center, Fort Sam Houston, Texas, (3) San Antonio Uniformed Services Health Education Consortium, Fort Sam Houston, Texas

Introduction/Statement of the Problem: We present a case of a young infantry soldier with left lower extremity fractures and shrapnel wounds, who developed a peripheral neuritis. He had pain from the medial anterior tibial region to his medial foot, which affected his ambulation. He had severe allodynia to light touch and marked hyperpathia. His skin, hair and nail growth were normal (except scars). Given the distribution of symptoms, lack of vasomotor, sudomotor or autonomic changes, combined with electrodiagnostic testing results, he was diagnosed with Saphenous neuralgia. A Saphenous nerve diagnostic block, using local anesthetic with ultrasound and nerve stimulation guidance gave the patient 100% relief; therefore he elected to have a neuroablative procedure. Materials and Methods: Cryo-ablation of the saphenous nerve using ultrasound (for visualization the "ice ball") and nerve stimulation guidance, while utilizing a Trans-Sartorial approach to the nerve above the left knee was performed. Results: The patient was seen 4 weeks following the procedure and reported being completely pain free, off of all oral analgesics and running 4 miles daily. On exam, he had no evidence of allodynia, hyperpathia or hypoesthesia. Conclusions: Cryo-ablation of painful sensory nerves is unique, as it rarely produces a deafferantation syndrome or neuromatous disease because it only destroys the myelin sheath which prevents the nerve from generating painful, distal stimuli. It is our belief that a technique combining ultrasound guidance with cryo-ablation appears to be superior to utilizing stimulation only by increasing duration and yielding better analgesia.

Funding: None