Ilioinguinal Nerve Entrapment and Pain in Endometriosis (case 2)

DB is a 26-year-old nulligravid female with dysmenorrhoea and a long-standing history of endometriosis. Dysmenorrhoea began at age 16 years and has become progressively worse. She describes two unique pain profiles. The first type of pain is midline, crampy in nature, and worsens with menses and after intercourse. The second pain is localised in the right lower quadrant, is sharp and debilitating, and occurs randomly. Laparoscopy had been performed in 1993, 1995 and 1996, and uterosacral nerve ablation and presacral neurectomy were performed. She is being treated with danazol and a GnRH agonist.

Physical examination revealed right lower quadrant tenderness over the site of the previous trocar. Pelvic examination was unremarkable. An injection of bupivacaine 0.5% with methylprednisolone provided short-term relief. Danazol was discontinued and the patient was placed on oxycodone and gabapentin with minimal relief. A diagnosis of ilioinguinal nerve entrapment was made and surgical exploration was carried out.

Starting just above the trocar site overlying the right pubic tubercle, a 6 cm incision was made along the course of the inguinal ligament between the pubic tubercle and the anterior superior iliac crest. The aponeurosis of the external oblique was opened along the course of its fibres and a dissection plane was developed between the external oblique and the internal oblique muscles. The ilioinguinal nerve was seen lying on top of the internal oblique muscle. The nerve was seen to bifurcate with one of the branches entering the scar tissue. The nerve was excised and frozen section confirmation obtained.

The patient noted immediate pain relief upon awakening and has been pain-free since surgery. She remains on GnRH agonist and add-back therapy.