CASE REPORTS

Paraduodenal Hernia Presenting asUnexplained Recurrent Abdominal PainRaj Patil, M.D., Claire Smith, M.D., and Michael D. Brown, M.D.Section of Digestive Diseases, Department of Internal Medicine and Department of Radiology, Rush-Presbyterian-St. Luke’s Medical Center, Chicago, Illinois

ABSTRACTWe present a case of a 29-yr-old female nurse who pre-sented with an 8-h history of abdominal pain. She had hadsimilar episodes (twice/yr) over the last 5 yr, and the painhad usually resolved spontaneously. Prior investigationsincluding laboratory studies, plain films of the abdomen, anabdominal and pelvic ultrasound, and a CT scan yielded nodiagnosis. Her pain was previously considered to be eitherpsychosomatic or a variant of irritable bowel syndrome. Onthis admission, an evaluation and subsequent enteroclysisrevealed a left paraduodenal hernia. The importance ofconsidering paraduodenal hernias in the differential diagno-sis of unexplained intermittent abdominal pain is discussedhere. (Am J Gastroenterol 1999;94:3614–3615. © 1999 byAm. Coll. of Gastroenterology)

INTRODUCTION

The surgical and radiological literatures contain the majorityof reported cases of paraduodenal hernia. However, becauseof the nature of the patients’ complaints, paraduodenal her-nias may present to a gastroenterologist. Early recognitionof paraduodenal hernias is important, as they can causepartial or complete obstruction, ischemia, and peritonitis. Asin this case, some patients may present with a history ofchronic and undiagnosed abdominal pain. The radiologicalfindings may be subtle and the hernias can have a recurrentpattern of intermittent herniation and spontaneous reductionleading to spontaneous resolution of the pain (1). Wepresent a case in which both the CT scan and ultrasoundfindings were negative, but a suspicious KUB and subse-quent enteroclysis revealed the diagnosis of a left paraduo-denal hernia.

CASE REPORT

A 29-yr-old female nurse with no past medical historypresented with a 8-h history of crampy intermittent abdom-inal pain. The pain localized to the umbilicus and did notradiate. She denied any nausea, vomiting, diarrhea, consti-pation, hematochezia, or melena with this or previous epi-sodes. The pain had no association with eating, and therewere no relieving or instigating factors. There was no as-

sociation of the pain with her menstrual periods. She has hadsimilar episodes (twice/yr) over the last 5 yr, and the priorepisodes of pain had resolved spontaneously. She deniedany alcohol use, and her only medications were oral con-traceptives.

Physical examination revealed a young woman in mod-erate distress holding her abdomen. On abdominal exam shehad normoactive bowel sounds, and no abdominal disten-tion. She had moderate periumbilical tenderness with someguarding. No rebound tenderness was present. She wassubsequently admitted for further evaluation.

Initial laboratory studies were as follows: UA-normal,UCG-normal, amylase 55 IU/L, lipase 70 IU/L, AST 20IU/L, ALT 40 IU/L, alkaline phosphatase 42 IU/L, andWBC 11,000. The electrolyte panel was normal. An initialKUB revealed a small loop of dilated small bowel in the midabdomen. Both an abdominal and pelvic ultrasound werenormal. A CT scan with oral contrast showed no evidence ofobstruction, and there was a small amount of free fluid in thepelvis. The patient continued to have pain, and an entero-clysis was done to rule out a Meckel’s diverticulum orinternal hernia. The enteroclysis revealed a left paraduode-nal hernia (Fig. 1). Surgery was consulted, and a surgicalrepair was performed.

DISCUSSION

Paraduodenal hernias, also known as mesocolic or mesen-tericoparietal hernias, are the most common types of internalhernias (1). They account for.50% of all internal hernias(2). These hernias can be either right or left sided but arethree times more frequent on the left. In clinical observa-tions, the male to female ratio is approximately 3:1. Patientsusually present as adults, with the mean age being 38.5 yr,but a few cases also present in childhood (4, 5).

Paraduodenal hernias are rare congenital anomalies inwhich the small intestine is completely or partially trappedbeneath the mesentery of the developing colon. Duringembryological development, the mesentery fails to fuse withthe parietal peritoneum and there is an associated abnormalrotation of the midgut (2).

Patients are usually asymptomatic and these hernias arefound incidentally (2). Clinical manifestations only occur

THE AMERICAN JOURNAL OF GASTROENTEROLOGY Vol. 94, No. 12, 1999© 1999 by Am. Coll. of Gastroenterology ISSN 0002-9270/99/$20.00Published by Elsevier Science Inc. PII S0002-9270(99)00676-0

when there is transient partial or complete obstruction of thesmall intestine in the hernia sac (4). Overall, paraduodenalhernias are rare and account for approximately 1% of allcauses of intestinal obstruction (4). When patients are symp-tomatic they usually present with chronic but intermittentcrampy abdominal pain, which can occur after eating andcan be relieved by changes in position (6). Other presentingsigns include abdominal distention, nausea, vomiting, de-hydration, and pain with standing (7). More ominous signs,which are associated with obstruction and subsequent per-foration such as fever, gangrene of the small intestine, andperitonitis, may also occur (7). Paraduodenal hernias thatcompletely obstruct and incarcerate are associated with a20% mortality (3).

Our patient had presented on multiple occasions in the

past with identical complaints. Previous laboratory studiesand imaging studies (plain films of the abdomen, ultrasound,CT scan) revealed no diagnosis and the pain relieved spon-taneously. Upon presentation, the plain film of the abdomenwas suspicious for a dilated loop of small bowel. Again, thepelvic/abdominal ultrasound and CT scan failed to yield adiagnosis. A Meckel’s scan was also negative. A subsequententeroclysis revealed the diagnosis of a left paraduodenalhernia. CT scan and ultrasound findings can be subtle ornormal. Spontaneous reduction of these hernias can lead tocomplete resolution of the patient’s symptoms (8, 9).

Paraduodenal hernias may mimic pain seen in functionalbowel disorders such as irritable bowel syndromes andnonulcer dyspepsia. Severe spontaneously resolving painwith long pain free intervals would suggest a paraduodenalhernia. Enteroclysis is diagnostic in this situation.

In our patient, a cyclical pattern of intermittent herniationwith transient partial obstruction and subsequent spontane-ous reduction accounts for her clinical picture over the last5 yr. She probably became symptomatic during transientpartial obstructions. Prompt surgical repair followed theradiographic diagnosis, resulting in symptomatic relief.

Reprint requests and correspondence:Michael D. Brown, M.D.,1725 West Harrison Street, Suite 206, Chicago, IL 60612.

Received Mar. 30, 1999; accepted Aug. 27, 1999.

REFERENCES

1. Day D. CT findings in left paraduodenal herniae. GastrointestRadiol 1988;13:27.

2. Olazabal A. Case report: CT diagnosis of nonobstructive leftparaduodenal hernia. Clin Radiol 1992;46:288–9.

3. Passas V, Karavias D, Grillas D, et al. Computed tomographyof left paraduodenal hernia. J Comput Assist Tomogr 1986;10:542–3.

4. Berardi R. Paraduodenal hernias. Surg Gynecol Obstet 1981;152:99–110.

5. Willwerth B. Congenital mesocolic (paraduodenal) hernia.Embryologic basis of repair. Am J Surg 1974;128:358–61.

6. Washauer D. CT diagnosis of paraduodenal hernia. Gastroin-test Radiol 1992;17:13–5.

7. Meyers M. Paraduodenal hernias: Radiologic and arterio-graphic diagnosis. Radiology 1970;95:29–37.

8. Donnelly F. Left paraduodenal hernia leading to ileal obstruc-tion. Pediat Radiol 1996;26:534–6.

9. Isabel L. Paraduodenal hernia. Aust New Zealand J Surg1995;65:64–6.

Figure 1. Left paraduodenal hernia revealed by enteroclysis.

3615AJG – December, 1999 Paraduodenal Hernia and Abdominal Pain