The usefulness of ICG video angiography in the surgical treatment of superior cluneal nerve entrapment neuropathy

Abstract

Superior cluneal nerve (SCN) entrapment neuropathy is a known cause of low back pain. Although surgical release at the entrapment point of the osteofibrous orifice is effective, intraoperative identification of the thin SCN in thick fat tissue and confirmation of sufficient decompression are difficult. Intraoperative indocyanine green video angiography (ICG-VA) is simple, clearly demonstrates the vascular flow dynamics, and provides real-time information on vascular patency and flow. The peripheral nerve is supplied from epineurial vessels around the nerve (vasa nervorum), and the authors now present the first ICG-VA documentation of the technique and usefulness of peripheral nerve neurolysis surgery to treat SCN entrapment neuropathy in 16 locally anesthetized patients. Clinical outcomes were assessed with the Roland-Morris Disability Questionnaire before surgery and at the latest follow-up after surgery. Indocyanine green video angiography was useful for identifying the SCN in fat tissue. It showed that the SCN penetrated and was entrapped by the thoracolumbar fascia through the orifice just before crossing over the iliac crest in all patients. The SCN was decompressed by dissection of the fascia from the orifice. Indocyanine green video angiography visualized the SCN and its termination at the entrapment point. After sufficient decompression, the SCN was clearly visualized on ICG-VA images. Low back pain improved significantly, from a preoperative Roland-Morris Questionnaire score of 13.8 to a postoperative score of 1.3 at the last follow-up visit (p < 0.05). The authors suggest that ICG-VA is useful for the inspection of peripheral nerves such as the SCN and helps to identify the SCN and to confirm sufficient decompression at surgery for SCN entrapment.