Meckel’s diverticulum (MD), named after the German anatomist Johann Friedrich Meckel who was the first to describe it in detail in 1809, is localized to within 100 cm from the ileocecal valve on the antimesenteric border of the ileum [1]. It is the commonest congenital anomaly of the gastrointestinal tract, being found in 1% to 3% of the general population [2, 3]. It is a true diverticulum containing all layers of the ileal wall and occurs when the vitelline duct persists past the seventh week of gestation. The reason for the rarity of this anomaly during clinical practice is that complications occur in only 4.0% to 6.4% of patients with MD [4, 5]. The proper management of asymptomatic diverticula is still being debated. This study was conducted to compare the clinicopathologic characteristics of incidentally found and symptomatic cases of MD with the aim of arriving at a recommendation regarding the management of incidental cases.

Patients and Methods

The medical records of all patients who underwent resection of MD and were managed at Princess Basma Teaching Hospital and Princess Rahma Pediatric Teaching Hospital from January 1990 to December 2002 were reviewed retrospectively. Both hospitals are located in northern Jordan, which is the second largest demographic area in Jordan, including about 1.25 million inhabitants. Patients whose incidentally found MDs were left untouched during the study period were not included owing to incomplete data.

The age and sex of the patients, mode of presentation, methods of diagnosis, anatomic characteristics of the MD, and treatment were analyzed, as was the outcome. The histologic findings were also evaluated.

The patients were divided into two groups. The incidental group included patients in whom the MDs were found incidentally during the course of laparotomy performed for reasons not related to the diverticular complications. The symptomatic group included patients who presented with complications related to the MDs.

Comparisons between the clinicopathologic characteristics of the patients in the two groups were performed using the SPSS statistical package version 9 (SPSS, Chicago, IL, USA). We assessed the statistical significance of the differences by the two-sample t-test for continuous variables and by the χ2 test for counts. When the expected number in any of the cells was less than 5, Fisher’s exact test was considered. Differences were considered statistically significant at p < 0.05.

Results

During the study period we identified 68 patients with histologically documented MD: 44 males (65%) and 24 females (35%). The incidental group included 40 patients (24 males), and the symptomatic group included 28 patients (20 males).

In the symptomatic group, 12 patients had small intestinal obstruction, 6 had Meckel’s diverticulitis, 6 had an ulcer in the diverticulum and presented with rectal bleeding (4 of them were less than 6 years of age), and the remaining 4 had perforation (a foreign body was found in one case). Seven patients had more than one complication related to the diverticulum.

A preoperative diagnosis was made in only four patients (5.9%) (all from the symptomatic group): three cases with 99mTc-pertechnetate scanning and one case with barium follow-through. In four patients from the symptomatic group, MDs were found and left intact during previous laparotomy performed 3 to 8 years before the onset of MD-related complications (appendectomy in three patients and perforated duodenal ulcer in the fourth patient).

The MD was resected in all cases: by diverticulectomy in 48 cases (including one case performed laparoscopically), by wedge ileal resection in 8, and by segmental ileal resection in the remaining 12 cases. Histologic examination of the resected diverticula revealed heterotopic gastric mucosa in four of the incidental group and in nine of the symptomatic group. There was an additional case of heterotopic pancreatic tissue in the group with complications. None of the diverticula contained tumors.

Postoperative complications occurred in two patients of each group (wound infection in one patient of each group, one patient with prolonged ileus in the incidental group, and one patient with adhesional obstruction in the symptomatic group). There were no anastomotic leaks or deaths in either group.

The clinical and pathologic characteristics of the patients in the incidental and symptomatic groups are summarized in Table 1. There was no significant difference between the two groups with respect to gender (p = 0.48). Patients in the symptomatic group were significantly younger than patients in the incidental group (p = 0.002). The diverticula in the symptomatic group tended to be longer (p = 0.001) with a narrower base (p = 0.001) than the diverticula in the incidental group. A diameter of ≤ 2 cm was significantly associated with more complications (p = 0.01). Heterotopic tissue was present more significantly in the symptomatic group than in the incidental group (p = 0.01). There was no significant difference in the morbidity rate between the two groups (p = 0.71).

Table 1. Clinical and pathologic characteristics of patients with Meckel’s diverticulum in the incidental and symptomatic groups.
Full size table

Discussion

Meckel’s diverticulum is a well known congenital abnormality of the distal ileum. It results from incomplete obliteration of the omphalomesenteric (vitelline) duct [2, 3]. Males constituted 65% of all our patients. It is well known that MD is more common in males, with a male/female ratio of 1.7:1.0 [6].

In our series 59% (40/68) of the patients had no symptoms related to the MD, and diagnosis of the diverticulum was incidental. Most MDs are clinically silent; the clinical symptoms occur in cases with complications [6]. The estimated total lifetime complication rate has been reported to be 4.2% to 6.4% [4, 5, 6, 7]. A risk of 3.7% at age 16, decreasing to zero by 76 years of age, has been reported [7].

Twelve of our patients presented with intestinal obstruction, and another six presented with painless rectal bleeding. Bowel obstruction of various types and per-anal rectal bleeding are the most common clinical presentations in adults and children, respectively [5, 8]. Obstruction is reported to occur in almost 40% of symptomatic patients [3]. There are two types of band related to MD that may cause intestinal obstruction secondary to volvulus or internal hernia [8]: (1) Omphalodiverticular bands are congenital fibrous bands between the MD and the umbilicus resulting from failure of the omphalomesenteric duct to regress completely. (2) Mesodiverticular bands result from persistence of the vitelline arteries. On the other hand, obstruction may result from stenosis secondary to chronic diverticulitis, perforation with secondary adhesions, or intussusception with a free diverticulum acting as a lead point [3]. Among our patients with intestinal obstruction, 10 had congenital bands and 2 had adhesions secondary to perforation. Diverticulitis, perforation, incarceration of the diverticulum in a hernia, volvulus, and “Meckel’s ileitis” are other complications that may be the presenting feature [3, 9, 10, 11]. In fact, some patients present with more than one of these complications, such as perforation and obstruction or bleeding with obstruction. Seven (10.3%) of our patients had such multiple complications.

The clinical manifestations of complicated MD may mimic any intraabdominal emergency, such as intestinal obstruction or perforation with peritonitis and abscess formation; accordingly, a preoperative diagnosis in an acute setting is difficult. It was possible in only four (5.9%) of our patients. Similarly, Ludtke et al. [12] reported preoperative diagnoses in only 4% of their cases.

Despite the advances in radiologic techniques, the diagnosis of MD is still difficult and is usually made during surgery. Abdominal plain radiography allows a diagnosis only of intestinal obstruction or perforation [13]. Ultrasonography, which may reveal pelvic abscess, a tubular fluid-distended diverticulum at a site far from the cecum, diverticular wall swelling, segmental thickening of the intestinal walls, and invagination, is not sufficiently specific [13]. Abdominal computed tomography (CT) scans may aid in the diagnosis if MD is suspected; they may show multiple fluid-filled, dilated loops of ileum with distal collapse [13, 14]. Other diagnostic modalities are barium studies, radioisotope studies, and angiography. The reported accuracy rate of barium studies is around 47% and is higher for adults than children [15]. As most symptomatic diverticula contain heterotopic gastric tissue, radionuclide imaging using technetium-99m pertechnetate scans is the method of choice [15, 16, 17]. However, a bleeding MD may give a false-negative result by pertechnetate imaging despite the presence of heterotopic gastric mucosa. The diagnostic accuracy of technetium-99m pertechnetate scintigraphy for children with a bleeding MD is around 92%, decreasing to 54% in adults [15]. Several agents have been used to improve the chance of a positive scan, including pentagastrin, glucagon, and cimetidine [2, 3]. When the scan is negative, superior mesenteric artery angiography is an alternative procedure for detecting MD and may reveal an omphalomesenteric artery [15, 18].

Heterotopic tissues such as gastric mucosa, duodenal mucosa, jejunal mucosa, and pancreatic tissue are present in 30% to 65% of patients with MD [3]. These tissues may result in gastrointestinal bleeding if they become ulcerated, or they may cause intestinal obstruction by intussusception; rarely, they transform into adenocarcinoma [10, 19]. Up to 90% of bleeding diverticula contain heterotopic mucosa [3]. Among our patients, 13 had heterotopic gastric mucosa (including the 4 pediatric patients who presented with per-anal bleeding), and 1 patient had heterotopic pancreatic tissue (documented histologically).

In none of our patients has a tumor developed in the MD. Malignant transformation from an MD is uncommon; it was reported in 0.5% to 5.0% of symptomatic MDs [2, 3, 20]. Tumors may rarely originate from the diverticulum; adenocarcinoma, villous adenoma, leiomyosarcoma, and carcinoid tumors arising from MD have been reported [19, 20, 21, 22].

It has been reported that symptomatic MD is more common in men, with a male/female ratio of 2:1 to 5:1 [4, 6]; moreover, more than 50% of patients with symptomatic MD are less than 10 years of age [6, 23]. Male sex, age < 40 years, long and narrowed-based MD, and the presence of palpable heterotopic tissue are reportedly among the main criteria to be taken into account when deciding to resect an asymptomatic MD [6, 7, 24]. Although we have found that patients in the symptomatic group were significantly younger than those in the incidental group, there was no difference between the two groups with respect to gender. This is probably due to the small number of patients in both groups. In concordance with other reports, heterotopic tissue was present significantly more often in the symptomatic group than in the incidental group [3, 6, 24]. Consistent with the literature, we found that the diverticula in the symptomatic group were significantly longer and had a narrower base diameter [3, 7]. A diameter of ≤ 2 cm was associated with significantly more complications, however, diverticula with diameters of > 2 cm were also prone to complications. A similar observation was noted by Mackey and Dineen [6], who suggested that the diameter of the MD should not be used to determine whether an incidental MD should be resected.

The average reported length of MD is 3 cm, with nearly 90% ranging from 1 to 10 cm [3], with a reported record length of 100 cm [2, 3, 6]. It has also been reported that 12% of diverticula < 2 cm versus 30% of those > 2 cm were symptomatic [6]. However, complications occur irrespective of the length of the diverticulum. The lengths of the MD in 6 (21%) of the 28 patients in the symptomatic group were ≤ 2 cm. Both long and short MD are prone to complications: long, narrow-base diverticula are thought to be more prone to obstruction or inflammation, whereas short, large-base diverticula are subject to foreign body entrapment [2, 3, 6].

All patients included in this study underwent surgical resection of the diverticulum. The treatment of choice for patients with symptomatic MD is surgical resection, although the treatment of asymptomatic MD is still controversial. Until recently diverticulectomy of an asymptomatic MD was generally not recommended [5, 7, 25, 26]. Soltero and Bill [5] found that approximately 800 asymptomatic MDs would have to be resected to prevent one death from an MD complication, but this concept has been challenged. Many reports [11, 12, 20, 27, 28, 29] have suggested resection of all incidentally found MDs unless there are contraindications; their opinion is based on the risk of serious short- and long-term complications related to MDs. Our data do not permit us to reach the same conclusion, as we do not have complete data on the patients with incidental MDs that were left untouched. On the other hand, and consistent with the above reports, we found that diverticulectomy of incidentally found MDs was associated with low morbidity and mortality. If the MDs had been removed when they were found incidentally in our four patients who later presented with MD-related complications, the morbidity and the second operation for these four patients would have been avoided. Given the considerable morbidity suffered by these four patients, we believe they would have been better served by a diverticulectomy. The risk of developing postoperative complications after such a diverticulectomy is only about 2%, and near-zero mortality figures have been reported since the early 1980s [3, 4, 7, 12]. Zingg et al. [29] suggested that diverticulectomy be performed for MD whether symptomatic or incidental because the risks of diverticulum-related complications outweigh the morbidity after simple resection of MD. Similarly, Cullen et al. [4] reported that because the risk of complications of MD has not been found to decrease with age, the benefits of diverticulectomy for the incidental MD outweighed its attending morbidity and mortality. Additionally, Romano et al. [20] suggested that because of the risk of neoplastic degeneration the MD should be resected even when it is discovered incidentally.

In one of our patients, the incidental MD was removed laparoscopically during the course of laparoscopic cholecystectomy. Laparoscopic resection of MD has been reported in recent years [17, 30] and may lower the threshold for surgeons in regard to removing the incidentally discovered MD.

Conclusions

Preoperative diagnosis of MD is difficult, and MD can cause many serious abdominal complications. We believe that resection of incidentally found MDs does not increase operative morbidity and mortality.

Résumé

Bien que le diverticule de Meckel (DM) soit l’anomalie congénitale gastrointestinale la plus fréquente, il existe toujours de controverses en ce qui concerne la meilleure façon d’aborder la prise en charge du DM asymptomatique. Les caractéristiques cliniques, les modes de présentation et la prise en charge de tous les patients ayant eu une résection du DM dans nos hôpitaux entre 1990 et 2002, ont été analysés à partir de leurs dossiers. Le DM a été réséqué chez 68 patients qui ont été divisés en deux groupes: le groupe «incidental» ou le DM a été découvert et réséqué de façon fortuite (40 patients, dont 24 hommes); le groupe «symptomatique» où le DM a été découvert et traité en raison de complications en rapport avec le DM (28 patients, dont 20 hommes). Le diagnostic n’a été réalisé en préopératoire que dans quatre cas. Chez quatre patients dans le groupe «symptomatique», le DM était déjà connu lors d’une laparotomie précédente, mais sans avoir été enlevé. On n’a retrouvé aucune différence statistiquement significative entre les deux groupes en ce qui concerne le sexe (p = 0.48). Par rapport aux patients du groupe «incidental», les patients du groupe «symptomatique» étaient significativement plus jeunes (p = 0.002), les diverticules plus longs (p = 0.001) et leur base plus étroite (p = 0.0001). Un diamètre supérieur ou égal à 2 cm était significativement associé à plus de complications (p = 0.01). Il n’y avait pas de différence statistiquement significative en ce qui concerne la morbidité entre les deux groupes (p = 0.71). Il n’y avait aucune mortalité. Le diagnostic préopératoire du DM est difficile, et devrait toujours être présent à l’esprit en cas d’abdomen aigu. La résection d’un DM retrouvé de façon fortuite n’est pas associée à une morbidité ou mortalité opératoires augmentées.

Resumen

Aunque el divertículo de Meckel es una de las más frecuentes malformaciones congénitas gástrointestinales, se continua debatiendo que tipo de tratamiento sería el más adecuado para los divertículos asintomáticos. Revisamos todas las historias clínicas de los pacientes que fueron sometidos en nuestro Hospital a una resección del divertículo de Meckel entre 1990 y 2002. Se analizaron las características clínicas, la forma de presentación y los tratamientos realizados. En 68 pacientes se resecó el divertículo de Meckel. Los pacientes se dividieron en 2 grupos: el grupo accidental que incluyó 40 pacientes (24 varones) en que el diagnóstico fue accidental; el grupo sintomático 28 pacientes (20 varones), que presentaron complicaciones referibles al divertículo. El diagnóstico preoperatorio se efectuó tan solo en 4 casos. En 4 pacientes del grupo sintomático el divertículo de Meckel se encontró a la izquierda, no explorada en laparotomías previas. No hubo diferencias significativas entre ambos grupos por lo que al género se refiere (p = 0.48). Los pacientes del grupo sintomático fueron significativamente más jóvenes que los del grupo accidental (p = 0.002). Los divertículos en el grupo sintomático fueron más largos (p = 0.001) y con una base más estrecha (p = 0.001) que los divertículos del grupo accidental. Un diámetro ≤ 2 cm se acompañaba de un mayor número de complicaciones (p = 0.01). Tejido heterotópico se encontró con más frecuencia en el grupo sintomático que en el accidental (p = 0.01). La morbilidad fue semejante en ambos grupos (p = 0.71). No hubo mortalidad alguna. El diagnóstico preoperatorio de un divertículo de Meckel es difícil y ha de ser tenido en cuenta en todos los casos de abdomen agudo. La resección de un divertículo descubierto accidentalmente no incrementa la morbi-mortalidad operatoria.