AB159. Femoral nerve palsy post open inguinal hernia repair—case report and literature review

Background: Inguinal hernia repair is one of the most common surgical procedures performed worldwide. Postoperative pain control is very important and recently nerve block has gained popularity as an alternative to opioid use. Transient femoral nerve palsy (TNFP) is a potential complication of ilioinguinal nerve block but it is extremely rare with only a few cases reported. We discuss a case of TNFP post-left inguinal hernia repair to highlight this rare complication.

Methods: A 17-year-old male with clinically and radiologically confirmed left inguinal hernia underwent open mesh repair (Lichtenstein repair). At the end of the procedure he had ilioinguinal and iliohypogastric nerve block (10 mL, 0.5% bupivacaine). In the recovery room, he developed numbness of his anteromedial aspect of his left thigh with weakness of hip flexion and paralysis of quadriceps with an inability to extend his knee. He was reviewed by the anaesthetic team and was admitted overnight. His symptoms resolved spontaneously within 18 hours. He was subsequently discharged and followed up in the surgical out patient department (OPD) 2 weeks, 6 weeks and 6 months later and there were no residual neurological symptoms.

Results: TNFP post open hernia repair is very rare. Mechanisms of femoral nerve injury include suturing, stapling, scar tissue entrapment or direct compression.

Conclusions: Careful attention is needed to the technique of local anaesthesia post-operatively (avoid deep infiltration, lowest volume and concentration used, ultrasound use) to avoid potential morbidity if this complication is not recognised.

Keywords: Hernia repair; femoral nerve palsy; general surgery