HARVEY B. STONE,1 referring specifically to abdominal hernias, tersely stated: "The one essential condition for the existence of hernia is a defect in the containing and restraining structures of the abdomen which permits its contents to protrude beyond their normal limits." Transmesenteric hernias, not possessing a hernial sac but consisting merely of a protrusion of a loop of bowel or omentum through a hole in the mesentery, like most other internal hernias, barely fulfil the one essential condition mentioned.
There are many varieties of abdominal hernia. The containing structures of the abdomen comprise the most common varieties, including direct and indirect inguinal, femoral, umbilical, ventral, diaphragmatic, lumbar, obturator, sciatic and perineal hernias. The restraining structures of the abdomen comprise most of the varieties of internal hernia, such as paraduodenal, cecal and intersigmoid hernias, hernia into the foramen of Winslow and hernias through defects or holes in the mesocolon
JOHNSON JR. INTERNAL HERNIAReview of Literature and Report of an Obstructed Transmesenteric Hernia and of an Intersigmoid Hernia. Arch Surg. 1950;60(6):1171-1182. doi:10.1001/archsurg.1950.01250011196014