Lumbar hernias are rare abdominal wall hernias that occur in the posterolateral abdominal wall. Intra-peritoneal or extra-peritoneal contents typically protrude through defects in one of two anatomical triangles. The superior lumbar triangle (Grynfeltt-Lesshaft triangle) is an inverted triangle bordered by the 12th rib superiorly, the internal oblique muscle laterally, and the erector spinae muscle medially. The inferior lumbar triangle (Petit\'s triangle) is an upright triangle bordered by the iliac crest inferiorly, the external oblique muscle laterally, and the latissimus dorsi muscle medially. Surgical repair has been described via open or laparoscopic approach. A 69-year-old male patient presented with right flank pain and swelling. He was involved in a motorcycle accident 10 months prior, which likely resulted in the development of a traumatic lumbar hernia which was demonstrated on the CT scan. The hernia was clinically incarcerated, and the defect contained the cecum and ileocecal valve. The defect was noted just superior to the iliac crest, by definition, making this an inferior lumbar hernia or a Petit\'s hernia. The hernia was repaired via robotic-assisted laparoscopic transabdominal approach. A peritoneal flap was created exposing the fascial defect. The fascia was primarily repaired with suture. The defect was reinforced with an 11.4 cm round Ventralight ST mesh in the preperitoneal space. The patient tolerated the procedure well with no acute complications. He was discharged the same day as an outpatient with appropriate pain control. Short-term follow-up demonstrated no recurrent hernia present and symptoms resolved. Lumbar hernias are a rare occurrence with no gold standard technique for repair. The benefits of the laparoscopic approach have been described over the open approach. This case report describes utilizing a minimally invasive approach to primarily repair a lumbar hernia defect while also reinforcing the hernia with mesh in the preperitoneal space.

Lumbar hernias are quite rare, even more so when primary or of spontaneous nature. These defects in the lumbar region demand a comprehensive knowledge of the anatomy of the lateral abdominal wall and paraspinal muscles. Given the proximity of bone structures, they can pose a surgical challenge when trying to achieve an ideal dissection and appropriate mesh overlap. The authors report the case of a primary Petit\'s hernia that underwent an open anterior surgical approach with the use of a preperitoneal mesh. In addition to the described surgical technique, the article also aims to detail the diagnosis and anatomic classification of this rare pathology.