Intraoperative Ultrasound-Assisted Peripheral Nerve Surgery
Intraoperative Ultrasound-Assisted Peripheral Nerve Surgery
A 35-year-old woman who previously underwent a craniotomy presented with a painful lump over her right occipital bone. The lesion enlarged over a period of 6 months. Intraoperative US was used to identify the lesion, which appeared to be hypoechoic, elongated, and nodular. The mass was found to be a 2 × 1–cm lesion arising from the right greater occipital nerve. The lesion was excised and the proximal end of the nerve was buried in muscle. Pathological examination revealed a neurofibroma (Fig. 1).
A 54-year-old woman suffered a crush injury, resulting in partial amputation of her left hand 12 years prior to presentation to our clinic. She previously underwent 2 resections of neuroma 2–3 years after her injury. She presented to our clinic with extreme hyperalgesia, allodynia, and phantom limb pain. MRI done prior to surgery showed multiple neuromas in multiple peripheral nerve distributions (Fig. 2). Intraoperative US was used to guide dissection for a total of 8 neuromas. One large neuroma was identified as a hypoechoic mass arising from the anterior interosseous nerve in the forearm, which was treated with external neurolysis, fascicle splitting, and grafting, with intramuscular transposition. Two lesions were found arising from the ulnar nerve near Guyon's canal, which were also treated with external neurolysis, fascicle splitting, and grafting, followed by intramuscular transposition. Two smaller dorsal digital neuromas and 3 small volar digital neuromas were also excised.
A 42-year-old man (a drummer) presented with pain, claudication, and cramping in his right leg. He previously underwent fasciotomy. Intraoperative US was used to localize 2 lesions, 1 arising from the medial sural nerve and 1 arising from the lateral sural nerve; both were hypoechoic and showed loss of fascicular pattern. Both were treated with excision and intramuscular transposition.
A 52-year-old man had an inguinal hernia repaired with mesh 16 years prior to presentation to our clinic. He had experienced progressive pain in the region, which had now become disabling. On physical examination, he was found to have a positive Tinel's sign on the medial aspect of the scar and was taken to surgery. Intraoperative US was used to identify a 5-mm hypoechoic nodular mass in the area of his previous surgery and to guide dissection down to the right ilioinguinal nerve. A Prolene (Ethicon) stitch was found through the neuroma, which was treated with excision and intramuscular transposition.
A 44-year-old man had pain in his right popliteal fossa. Five years earlier, he had experienced the same pain and 2 schwannomas were removed from his right calf; a third was left behind because the prior surgeon found it "attached to a nerve." We re-explored the area, using intraoperative US for guidance (Fig. 3). Attached to a cutaneous nerve was a rounded hypoechoic nodule, which was treated with excision, while preserving the parent nerve. Pathology revealed the mass to be a schwannoma. Figure 4 shows the setup of the operating room with the US machine and radiologist.
Case Series
Case 1: Neurofibroma of the Right Greater Occipital Nerve
A 35-year-old woman who previously underwent a craniotomy presented with a painful lump over her right occipital bone. The lesion enlarged over a period of 6 months. Intraoperative US was used to identify the lesion, which appeared to be hypoechoic, elongated, and nodular. The mass was found to be a 2 × 1–cm lesion arising from the right greater occipital nerve. The lesion was excised and the proximal end of the nerve was buried in muscle. Pathological examination revealed a neurofibroma (Fig. 1).
Case 2: Multiple Traumatic Neuromas of the Arm and Hand After a Crush Injury
A 54-year-old woman suffered a crush injury, resulting in partial amputation of her left hand 12 years prior to presentation to our clinic. She previously underwent 2 resections of neuroma 2–3 years after her injury. She presented to our clinic with extreme hyperalgesia, allodynia, and phantom limb pain. MRI done prior to surgery showed multiple neuromas in multiple peripheral nerve distributions (Fig. 2). Intraoperative US was used to guide dissection for a total of 8 neuromas. One large neuroma was identified as a hypoechoic mass arising from the anterior interosseous nerve in the forearm, which was treated with external neurolysis, fascicle splitting, and grafting, with intramuscular transposition. Two lesions were found arising from the ulnar nerve near Guyon's canal, which were also treated with external neurolysis, fascicle splitting, and grafting, followed by intramuscular transposition. Two smaller dorsal digital neuromas and 3 small volar digital neuromas were also excised.
Case 3: Medial and Lateral Sural Neuromas
A 42-year-old man (a drummer) presented with pain, claudication, and cramping in his right leg. He previously underwent fasciotomy. Intraoperative US was used to localize 2 lesions, 1 arising from the medial sural nerve and 1 arising from the lateral sural nerve; both were hypoechoic and showed loss of fascicular pattern. Both were treated with excision and intramuscular transposition.
Case 4: Iatrogenic Ilioinguinal Nerve Injury
A 52-year-old man had an inguinal hernia repaired with mesh 16 years prior to presentation to our clinic. He had experienced progressive pain in the region, which had now become disabling. On physical examination, he was found to have a positive Tinel's sign on the medial aspect of the scar and was taken to surgery. Intraoperative US was used to identify a 5-mm hypoechoic nodular mass in the area of his previous surgery and to guide dissection down to the right ilioinguinal nerve. A Prolene (Ethicon) stitch was found through the neuroma, which was treated with excision and intramuscular transposition.
Case 5: Cutaneous Nerve of Thigh schwannoma
A 44-year-old man had pain in his right popliteal fossa. Five years earlier, he had experienced the same pain and 2 schwannomas were removed from his right calf; a third was left behind because the prior surgeon found it "attached to a nerve." We re-explored the area, using intraoperative US for guidance (Fig. 3). Attached to a cutaneous nerve was a rounded hypoechoic nodule, which was treated with excision, while preserving the parent nerve. Pathology revealed the mass to be a schwannoma. Figure 4 shows the setup of the operating room with the US machine and radiologist.
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