Lumbar Hernia

Can occur in either superior lumbar triangle of Grynfeltt-Lesshaft or inferior lumbar triangle of Petit

– Superior lumbar triangle of Grynfeltt-Lesshaft defined by 12th rib superiorly, superior border of internal oblique inferiorly, and erector spinae medially

– Inferior lumbar triangle of Petit defined by latissimus dorsi muscle medially, iliac crest inferiorly, and free border of external oblique muscle laterally

Overall, hernias are more common in superior triangle

IMAGING

• Disruption of thoracolumbar fascia at insertion of aponeurosis of internal oblique and transverse abdominal muscles

• Hernia may contain extraperitoneal fat, colon, kidney, or intraperitoneal structures (small bowel, ascites)

Most commonly involved are colon and small bowel

TOP DIFFERENTIAL DIAGNOSES

• Abdominal wall neoplasms

• Abdominal wall hematoma

• Abdominal wall lipoma

PATHOLOGY

• 80% of lumbar hernias are acquired

Can be spontaneous (especially in older patients and patients with excessive weight loss) or secondary to trauma, infection, or previous surgery in flank