Genitofemoral nerve protection during the lateral retroperitoneal transpsoas approach

The minimally invasive lateral retroperitoneal approach for lumbar fusions is a novel technique with good results, but also with significant sensory and motor complications.

To present the early results of a modified surgical technique, in which the psoas muscle is dissected under direct visualization.

Thirteen consecutive patients with L4-5 or L3-4 pathology were prospectively followed after being treated using a minimally invasive lateral approach with direct exposure of the psoas muscle before dissection. There were 7 woman and 6 men with a mean age of 52.3 years. Perioperative parameters like operative time, estimated blood loss, and length of stay, were noted. Pain, paresthesia, and motor weakness, as well as any other complications, were evaluated at 2 weeks and 3 months postoperatively.

The mean operative time, estimated blood loss, and length of stay were 163 minutes, 126 mL, and 3 days, respectively. One patient exhibited anterior thigh pain and paresthesia at 2 weeks, both of which resolved by 3 months. Two patients experienced superficial wound infections that healed with antibiotics. The genitofemoral nerve was identified and protected in 7 patients; in 4 patients, it had a more posterior anatomic location than expected. The femoral nerve was not exposed or detected in the operative field by neuromonitoring, nor were there any symptoms related to a femoral nerve injury in any patient.

Dissection of the psoas muscle under direct visualization during the minimally invasive lateral approach may provide increased safety to the genitofemoral and femoral nerves.