Abdominal internal hernias are reported in less than 1% of autopsies and in 0.5% to 4.1% of cases of intestinal obstruction.1 The types and relative frequencies of internal hernias are as follows: paraduodenal, 53%; pericecal, 13%; foramen of Winslow, 8%; transmesenteric and transmesocolic, 8%; pelvic, 6%; intersigmoid, 6%; retroanastamotic, 5%; and transomental, 1%. Internal hernias may be acquired or congenital. Paraduodenal hernias arise from a deficiency in midgut rotation. Unlike malrotation, the duodenum crosses the midline, and the cecum is located in the right lower quadrant.1
Overall, 2% of the population has a peritoneum-lined sac (Landzert fossa) that resides in the mesentery of the proximal descending colon. This sac represents a left-sided paraduodenal hernia and is located to the left of the fourth portion of the duodenum, with a neck formed by the inferior mesenteric vessels anteriorly (vascular arch of Treitz). In Figure 1A, small-bowel loops are seen encapsulated in the mesentery of the proximal descending colon (thin arrow) with the hernia neck (small arrow) anterior to the superior mesenteric vessels and the duodenum (large arrow) crossing the midline. Figure 1B demonstrates the cecum (thick arrow) in the right lower quadrant. Figure 2 demonstrates the Landzert fossa after the herniated bowel has been reduced laparoscopically.
Noncontrast computed tomogram of the abdomen shows the upper (A) and lower (B) cuts. See text for description of arrows.
Laparoscopic view of the left upper abdomen.
While most paraduodenal hernias are left sided, 25% are right sided. Right-sided paraduodenal hernias are located in the Waldeyer fossa in the jejunal mesentery. The hernia sac is inferior to the third part of the duodenum, with the sac neck formed by the superior mesenteric artery anteriorly.2
This patient's clinical presentation is typical of internal hernias. These hernias may be complicated by bowel obstruction, strangulation, and necrosis. Thus, all internal hernias must be surgically treated. With the exception of right-sided paraduodenal hernias and foramen of Winslow hernias, the surgical approach is the same for all internal hernias: bowel reduction, resection of any necrotic bowel, and closure of the hernia defect. To reduce the small bowel out of a left paraduodenal hernia sac, division of the inferior mesenteric vessels at the neck of the sac may be necessary. In this case, the small bowel was reduced easily without dividing the mesenteric vessels, and the Landzert fossa was subsequently closed with interrupted intracorporal sutures. This case represents only the ninth reported case of a laparoscopically treated left paraduodenal hernia repair.3
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Correspondence: Fred Brody, MD, MBA, Department of Surgery, George Washington University Medical Center, 2150 Pennsylvania Ave NW, Ste 6B, Washington, DC 20037 (firstname.lastname@example.org).
Accepted for Publication: November 24, 2010.
Author Contributions:Study concept and design: Al-Mufarrej, Kaza, Ahari, Abell, and Brody. Drafting of the manuscript: Al-Mufarrej. Critical revision of the manuscript for important intellectual content: Al-Mufarrej, Kaza, Ahari, Abell, and Brody. Administrative, technical, and material support: Al-Mufarrej. Study supervision: Kaza, Abell, and Brody.
Financial Disclosure: None reported.
Image of the Month—Diagnosis. Arch Surg. 2011;146(2):234. doi:10.1001/archsurg.2010.344-b