Meckel's Diverticulum

Author: John P. Martin, Kerri Charles
Date: Feb 15, 2000

Although Meckel's diverticulum is the most prevalent congenital abnormality of the gastrointestinal tract, it is often difficult to diagnose. It may remain completely asymptomatic, or it may mimic such disorders as Crohn's disease, appendicitis and peptic ulcer disease. Ectopic tissue, found in approximately 50 percent of cases, consists of gastric tissue in 60 to 85 percent of cases and pancreatic tissue in 5 to 16 percent. The diagnosis of Meckel's diverticulum should be considered in patients with unexplained abdominal pain, nausea and vomiting, or intestinal bleeding. Major complications include bleeding, obstruction, intussusception, diverticulitis and perforation. The most useful method of diagnosis is with a technetium-99m pertechnetate scan, which is dependent on uptake of the isotope in heterotopic tissue. Management is by surgical resection. (Am Fam Physician 2000;61:1037- 42,1044.)

Meckel's diverticulum is a true intestinal diverticulum that results from the failure of the vitelline duct to obliterate during the fifth week of fetal development.1,2 It contains all normal layers of the intestinal wall and, in approximately 50 percent of cases, contains tissue from other sites (ectopic tissue).2 This ectopic, or heterotopic, tissue can often be the cause of complications occurring in Meckel's diverticulum.

Meckel's diverticulum occurs in about 2 percent of the population, making it the most prevalent congenital abnormality of the gastrointestinal tract. Even so, it can be difficult to diagnose.2 It can be asymptomatic or mimic common abdominal disorders such as Crohn's disease, appendicitis and peptic ulcer disease.2 Many primary care physicians have never seen a patient with this abnormality, and the management involves a sometimes controversial decision about whether to surgically remove an incidentally discovered Meckel's diverticulum.

Illustrative Case

A 60-year-old woman presented to the emergency department with a complaint of nonradiating, waxing and waning epigastric abdominal pain of two to three hours' duration, with associated nausea and anorexia. There was no history of fever, diarrhea, constipation, melena, hematochezia or urinary symptoms.

The patient had been evaluated and treated for abdominal complaints in the past. She had undergone a total abdominal hysterectomy and bilateral salpingo-oophorectomy for cervical stenosis and pelvic pain with incidental appendectomy one year before and a cholecystectomy several years earlier. Abdominal ultrasounds, multiple upper gastrointestinal studies and an air contrast barium enema had been normal since the cholecystectomy. These examinations were performed because of continued complaints of nonspecific abdominal pain.

The patient's physical examination was nonspecific. She was afebrile and normotensive and had a normal pulse and respiration. Her abdomen had nonlocalized upper- to midabdominal tenderness with no guarding or rebound, no organ enlargement or masses, and positive bowel sounds. The rectal examination was normal, with guaiac-negative stool. Her complete blood cell count was normal with a white blood cell count of approximately 9,000 per mm3 (9 3 109 per L). Electrolytes, liver function, urinalysis and amylase levels were all normal. The chest radiograph was clear, and the flat and upright abdominal films were normal, without air-fluid level, dilation or free air.

The patient was admitted to the hospital with intractable abdominal pain. She was given nothing by mouth and was placed on maintenance intravenous fluids. The next day, examination revealed right lower quadrant tenderness with slight guarding and rebound, which was confirmed on pelvic examination. The patient's stool was still guaiac- negative. However, her temperature had climbed to 37.5[degree sign]C (99.6[degree sign]F), and her white blood cell count had fallen to 5,000 per mm3 (5 3 109 per L) with a left shift. Hemoglobin and hematocrit levels, as well as electrolytes, blood urea nitrogen and creatinine levels, remained normal.

During her previous abdominal surgery, an incidentally discovered wide- mouthed, relatively short Meckel's diverticulum had been noted. The physician had determined that it was asymptomatic and elected to leave the diverticulum in place. In light of the patient's current condition, surgery was recommended for suspected Meckel's diverticulum.

At laparotomy, an axially torsed, gangrenous Meckel's diverticulum was found without ileal volvulus. The lead point for the torsion was a fibrous adhesion attached between the distal tip of the diverticulum and the peritoneal surface. A diverticulectomy and segmental ileal resection were performed, and the patient had an uneventful postoperative course and recovery.

Incidence and Natural History

The incidence of Meckel's diverticulum in the general population has been estimated to be about 2 percent; reports from autopsy and retrospective studies range from 0.14 to 4.5 percent.1,3-6 Although Meckel's diverticulum occurs equally in both sexes,7-9 it causes complications more frequently in males1,9,10 and, therefore, is more often diagnosed in males.7 Early literature11,12 has quoted complication rates as high as 25 percent; however, results of a 15-year study set the risk of developing complications at 4.2 percent.13 This study of 202 patients did not include any cases of incidentally found diverticulum; it is the largest series of cases of complicated Meckel's diverticulum ever reported.

A currently disputed issue is whether the incidence of complications decreases with advancing age. The 15-year study stated that the incidence of complications decreases with age.13 Two retrospective studies of patients diagnosed with Meckel's diverticulum also reached this conclusion.1,4

A population-based study10 from 1950 to 1992 found the incidence of a diverticular complication to be 87.4 per 100,000 person-years, translating to a 6.4 percent lifetime risk (lifetime = 80 years of age) of a person developing a complication related to the diverticulum. In this study,10 there was no decrease in the likelihood of complications with age. More recently, a 10-year retrospective study9 also reported an even age distribution in patients with complications. This issue of correlating age with the incidence of complications is not settled; therefore, age alone should not be the sole criterion for a decision to perform an incidental diverticulectomy.

Anatomy and Embryology

During early fetal development, the fetal midgut is attached to the yolk sac for nutrition via the omphalomesenteric duct (vitelline duct, or yolk stalk).1 If this duct does not involute by the seventh week of gestation, various developmental remnants may be left1 (Figure 1). Failure of the most proximal portion of the duct to obliterate results in a Meckel's diverticulum.14 The yolk sac is continuous with the embryo and contains all layers of the intestinal wall; therefore, the diverticulum that forms from the yolk stalk also contains all layers of the intestinal wall.15

In addition to the normal layers of the intestinal wall, approximately 50 percent of diverticula contain ectopic tissue.2 In surgical exploration, this ectopic tissue has been described as "strange granular tissue"; however, in one 15-year study, diagnosis by palpation at surgery led to 14 false-positive results.14 This overdiagnosis indicates that palpation at surgery is not a definitive indication of pathology.14

Meckel's diverticulum arises from the antimesenteric border-the part of the intestine that lies opposite the mesenteric attachment. Ninety percent of the diverticula are within 90 cm of the ileocecal valve, although reports of diverticula up to 180 cm from the ileocecal valve have occurred.7 Its blood supply comes from a terminal branch of the superior mesenteric artery that crosses the ileum to the diverticulum.1,7,16,17 Meckel's diverticulum typically presents as short and wide mouthed, as in the case study presented here.18 This shape often makes detection difficult.18,19

Pathologic Association or Conditions

Ectopic tissue (tissue existing in other than its original intended location) is found in up to 55 percent of Meckel's diverticula.20 Gastric and pancreatic tissue predominate, with corresponding incidences of 60 to 85 percent and 5 to 16 percent.1,10,16 The highly acidic secretions of gastric tissue may cause ulcerations that often lead to early diagnosis because of symptoms of gastrointestinal bleeding.7 The alkaline secretions of ectopic pancreatic tissue can also cause ulcerations.14 Reports have cited other tissues such as colonic, duodenal, jejunal, hepatic and endometrial; however, these occurrences are quite rare and are not in reports of complications.3,7,16

Malignancies may also occur but are found in only 0.5 to 4.9 percent of patients with complications of Meckel's diverticulum. Sarcomas are the most common neoplasm, followed by carcinoids and adenocarcinomas.3

13. Soltero MJ, Bill AH. The natural history of Meckel's diverticulum and its relation to incidental removal. Am J Surg 1976;32:168-73.

14. Artigas V, Calabuig R, Badia F, Rius X, Allende L, Jover J. Meckel's diverticulum: value of ectopic tissue. Am J Surg 1986;151:631-4.

15. Moore KL, Persaud TV. The developing human. 5th ed. Philadelphia: Saunders, 1993:255-7.

16. Garretson DC, Frederich ME. Meckel's diverticulum. Am Fam Physician 1990;42:115-9.

17. D'Souza CR, Prokopishyn H. Axial volvulus of the small bowel caused by Meckel's diverticulum. Surgery 1993;114:984-7.

18. Rutherford RB, Akers DR. Meckel's diverticulum: a review of 148 pediatric patients, with special reference to the pattern of bleeding and to mesodiverticular vascular bands. Surgery 1966;59:618-26.

19. Sanders LE. Laparoscopic treatment of Meckel's diverticulum. Obstruction and bleeding managed with minimal morbidity. Surg Endosc 1995;9:724-7.

20. Haubrich WS, Schaffner F, Berk JE, Bockus HL. Gastroenterology. Vol 2. 5th ed. Philadelphia: Saunders, 1995:912-4.

21. Yamaguchi M, Takeuchi S, Awazu S. Meckel's diverticulum. Investigation of 600 patients in Japanese literature. Am J Surg 1978;136:247-9.

22. St. Vil D, Brandt Ml, Panic S, Bensoussan A, Blanchard H. Meckel's diverticulum in children: a 20-year review. J Pediatr Surg 1991;26:1289- 92.

23. Campione O, Tonini V, Cervellera M, Marrano E, Pasqualini E, Avanzolini A, et al. Acute Meckel's diverticulum in a senior patient. Minerva Chir 1998;53:743-5.

24. Simms M, Caldwell J, Lundgrin D. Inverted Meckel's diverticulum diagnosed with computed tomography: case report. Can Assoc Radiol J 1999;50:17-9.

25. Daneman A, Lobo E, Alton DJ, Shuckett B. The value of sonography, CT and air enema for detection of complicated Meckel diverticulum in children with nonspecific clinical presentation. Pediatr Radiol 1998;28:928-32.

26. Hughes JA, Hatrick A, Rankin S. Computed tomography findings in an inflamed Meckel diverticulum. Br J Radiol 1998;71:882-3.

27. Cooney DR, Duszynski DO, Camboa E, Karp MP, Jewett TC Jr. The abdominal technetium scan (a decade of experience). J Pediatr Surg 1982;17:611-9.

28. Schwartz MJ, Lewis JH. Meckel's diverticulum: pitfalls in scintigraphic detection in the adult. Am J Gastroenterol 1984;79:611-8.

29. Sfakianakis GN, Conway JJ. Detection of ectopic gastric mucosa in Meckel's diverticulum and in other aberrations by scintigraphy: I. Pathophysiology and 10-year clinical experience. J Nucl Med 1981;22:647- 54.

30. Huang CS, Lin LH. Laparascopic Meckel's diverticulectomy in infants: report of three cases. J Pediatr Surg 1993;28:1486-9.

31. Matsagas MI, Fatouros M, Koulouras B, Giannoukas AD. Incidence, complications, and management of Meckel's diverticulum. Arch Surg 1995;130:143-6.

32. Patsner B, Chalas E, Orr JW Jr, Mann WJ Jr. Stapler resection of Meckel's diverticulum during gynecologic cancer surgery. Gynecol Oncol 1990;38:197-9.

33. Martin JP. Axial torsion of a Meckel's diverticulum in a commander's secretary: a case report. San Antonio, Tex.: Annual Military Surgeon's Conference, 1985.

34. Guss DA, Hoyt DB. Axial volvulus of Meckel's diverticulum: a rare cause of acute abdominal pain. Ann Emerg Med 1987;16:811-2.

35. Hudson HM 2d, Millham FH, Dennis R. Vesico-diverticular fistula: a rare complication of Meckel's diverticulum. Am Surg 1992;12:784-6.

The Authors

JOHN P. MARTIN, M.D., is currently in private practice in Oneida, Tenn. He received his medical degree from Virginia Commonwealth University Medical College of Virginia, Richmond, and completed a residency in family medicine at Eglin Air Force Base, Fort Walton Beach, Fla. He was previously an assistant professor at the University of Tennessee Family Practice Center-Tipton, in Covington, Tenn.

PAMELA D. CONNOR, PH.D., is an associate professor in the Department of Family Medicine at the University of Tennessee, Memphis, College of Medicine. She obtained her doctorate in family and community medicine at the University of Utah School of Medicine, Salt Lake City.

KERRI CHARLES, J.D., is a second-year medical student at the University of Tennessee, Memphis, College of Medicine. She completed a law degree at Memphis State University.

Address correspondence to John P. Martin, M.D., Family Practice Center- Tipton, Suite 111, 1995 Highway 51 South, Covington, TN 38019. Reprints are not available from the authors.

Table 1Complications of Meckel's Diverticulum Percentage Percentage of symptomaticCharacteristic* Number of total patientsMore common in males 3:2 ratioMost commonObstruction of small intestine 23 5.7 33.8Inflammation 21 5.2 30.9Lower gastrointestinal bleeding 17 4.2 25.0Omphalomesenteric fistula 3 0.75 4.4Littre's hernia 8 2.0 11.8Miscellaneous 3 0.75 4.4*-From a study of 402 patients with Meckel's diverticulum.Adapted with permission from Mackey WC, Dineen P. A fifty-yearexperience with Meckel's diverticulum. Surg Gynecol Obstet 1983;156:56-

64.

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