Divertículo de Meckel / Meckel's diverticulum

El divertículo de Meckel es la anomalía más frecuente del intestino delgado, resultando de una incompleta obliteración del ducto vitelino a la 5-7 semana de desarrollo embriológico. La mayoría de los pacientes portadores son asintomáticos, pero pueden llegar a complicarse dando como resultado diverticulitis, obstrucción intestinal y más frecuentemente hemorragia.

Meckel's diverticulum: a review.

Meckel's diverticulum is the most prevalent congenital abnormality of the gastrointestinal tract. This anomaly is due to the incomplete obliteration of the omphalomesenteric duct during the 7th week of gestation and is classically located 2 feet proximal to the ileocecal valve. Variations of this congenital malformation have been recorded based on location, size, and form. While most of the population may be asymptomatic, clinical manifestation, including gastrointestinal bleed and intestinal obstruction, can emerge. Despite the frequency of Meckel's diverticulum, it is commonly misdiagnosed due to its mimicry of appendicitis. This article aimed to review this derailment of embryological development.

Pathogenic implications of remnant vitelline structures in gastroschisis.

PURPOSE: The pathogenesis of gastroschisis is unknown. It may be helpful in understanding its pathogenesis to know the structural relationships among umbilical components including umbilical vessels, urachus, and vitelline structures, and thus, the authors investigated the remnants of vitelline structures in a series of cases of gastroschisis. METHODS: Medical records of 41 cases with gastroschisis treated in our institute from 1979 to 2009 were retrospectively reviewed. RESULTS: Paraumbilical bands, possible remnants of vitelline structures, were observed in 4 cases (9.8%). All 4 bands were attached to the skin edge of the abdominal defect without incorporation into the umbilical cord. The band ended at the mesentery in 3 cases and at the antimesenteric site of the ileum in the remaining case. Histologic findings showed fibrous tissues in all cases. One was possibly associated with the development of colonic atresia. Another was noticed after silo reduction when herniated bowels became strangulated by the band. The other 2 cases were uncomplicated. CONCLUSIONS: Our findings may support the recently proposed hypothesis that the developmental failure of the yolk sac and related vitelline structures to merge with or to be incorporated into the umbilical stalk might be associated with the pathogenesis of the abdominal wall defect in gastroschisis. Paraumbilical bands derived from vitelline structures may possibly cause intestinal ischemia prenatally or postnatally.

Double heterotopic pancreas and Meckel's diverticulum in a child: do they have a common origin?

Heterotopic pancreatic tissue consists of normally differentiated pancreatic tissue without a real anatomic and vascular connection to the pancreas, whereas Meckel's diverticulum is one of the most important cause of lower gastrointestinal bleeding in children. Although heterotopic pancreatic tissue is related to various gastrointestinal diseases/malformations in both humans and animals, it is rarely associated with Meckel's diverticulum. Herein, we report a five-year old boy who presented with melena and hematochezia, which were discovered to be the result of Meckel's diverticulum. He also had multiple heterotopic pancreatic tissues in various parts of the gastrointestinal tract. The reason for this association is not known, but might involve some abnormalities of signaling molecules expressed in the development of the gastrointestinal tract and associated organs. In clinical practice, it is important to remember that Meckel's diverticulum and heterotopic pancreatic tissue might occur together or accompany various other gastrointestinal anomalies.

[Anatomohistological characteristics of Meckel's diverticulum in human fetuses].

BACKGROUND/AIM: Meckel's diverticulum (MD) is the most frequent anomaly of the small intestine. It appears after incomplete obliteration of the omphalomesenteric or viteline duct which normaly obliterates and disappears by the 9th week of gestation. The majority of MD do not give rise to any clinical symptoms and are encounted either incidentally, at examination or intervention, or due to complications which may occur (obstruction, hemorrhagy, rupture), and are described in many clinical reports. The aim of the study was to find out the incidence of MD in fetuses when the development of the alimentary tract is already finished. METHODS: The investigation was performed on 150 human fetuses of different sex and gastational age, using microdissection method. The cases with MD were photographed, described, their positions and dimensions were registered. The samples of MD taken for histological investigation were dyed with hematoksilin eosin method. RESULTS: Meckel's diverticulum was found in five fatuses (three male and two female); in one case the fibrous band was found. All of them were located on animesenteric margine of the small intestine at the average distance of 92.5 mm from the ileocecal junction. They were of different shape and dimensions, but of the normal constitution of the small intestine. CONCLUSION: The incidence of MD was 3.3%, and 4% of all the anomalies of the intestines connected to the disappearance of the viteline duct. It was more frequent in the male, located on antimesenteric margine of the small intestine, at the destination which highly correlated to the age of the fetus. Meckel's diverticule were of different shapes and dimensions but of the typical constitution of the small intestine.

Meckel's Diverticulum: A Case Report / Divertículo de Meckel: Reporte de Caso

Meckel's diverticulum is the most prevalent congenital anomaly of the gastrointestinal tract. It might remain completely asymptomatic or may mimic some disorders like Crohn's disease, Appendicitis and peptic ulcer diseases. A Meckel's diverticulum was found during routine dissection. A brief review of this anomaly, its embryological explanation, and probable clinical implications with its management is discussed in this report.

El diverticulo de Meckel es la anomalía congénita más prevalente del tracto gastrointestinal. Puede ser un remanente totalmente asintomático o puede provocar algunos desórdenes como la enfermedades de Crohn, apendicitis y úlcera péptica. Un diverticulo de Meckel fue encontrado durante una disección de rutina. Una breve revisión de esta anomalía, su explicación embriológica y probables implicaciones clínicas fueron discutidas en este trabajo.

Current management of umbilical abnormalities and related anomalies.

Prenatally, the umbilicus is of paramount importance, providing the gateway between the mother and the fetus. As the fetus becomes increasingly autonomous at the end of the second month of fetal life, the connections (vitelline, urachal) diminish in significance and involute. Disturbances in this process can result in a wide variety of abnormalities, ranging from relatively minor defects identified at birth (umbilical granulation tissue) to life-threatening complications quiescent until late adulthood (urachal carcinoma). This section will review the 'state of the art' in evaluation and management of these umbilical and related abnormalities.

Littre hernia: surgical anatomy, embryology, and technique of repair.

Littre hernia is the protrusion of a Meckel diverticulum through a potential abdominal opening. Alexis de Littre (1700) reported ileal diverticula and attributed them to traction. August Gottlieb Richter (1785) defined them as preformed, and Johann Friedrich Meckel (1809) postulated their embryologic origin. Sir Frederic Treves (1897) distinguished between Littre and Richter hernia (partial enterocele). Embryologically, Meckel diverticulum is the persistent intestinal part of the omphaloenteric duct through which the midgut communicates with the umbilical vesicle until the fifth week. It is found at the antimesenteric border of the ileum, usually located 30 to 90 cm from the ileocecal valve, measuring 3 to 6 cm in length and 2 cm in diameter. Usual sites of Littre hernia are: inguinal (50%), umbilical (20%), and femoral (20%). Meckel diverticulum may be accompanied in the sac by the ileal loop to which it is attached; rarely, it may undergo incarceration or strangulation, necrosis, and perforation. In children, it is mostly found in umbilical hernias, and the diverticulum is more prone to adhere to the sac. Repair of Littre hernia consists of resection of the diverticulum and herniorraphy; in perforated cases, care must be taken to not contaminate the hernia field.

From the archives of the AFIP. Meckel diverticulum: radiologic features with pathologic Correlation.

Meckel diverticulum is the most common congenital anomaly of the gastrointestinal tract, occurring in 2%-3% of the population. It results from improper closure and absorption of the omphalomesenteric duct. Meckel diverticulum is the most common end result of the spectrum of omphalomesenteric duct anomalies, which also include umbilicoileal fistula, umbilical sinus, umbilical cyst, and a fibrous cord connecting the ileum to the umbilicus. The formation of Meckel diverticulum occurs with equal frequency in both sexes, but symptoms from complications are more common in male patients. Sixty percent of patients come to medical attention before 10 years of age, with the remainder of cases manifesting in adolescence and adulthood. Heterotopic gastric and pancreatic mucosa are frequently found histologically within the diverticula of symptomatic patients. The most common complications are hemorrhage from peptic ulceration, small intestinal obstruction, and diverticulitis. Although the clinical, pathologic, and radiologic features of the complications of Meckel diverticulum are well known, the diagnosis of Meckel diverticulum is difficult to establish preoperatively.

Diverticulitis de Meckel / Meckel diverticulitis: radiologic and CT features

El divertículo de Meckel es la anomalía congénita más común del tracto gastrointestinal. Las complicaciones incluyen obstrucción intestinal, diverticulitis y sangrado. Presentamos un paciente de 32 años, de sexo masculino con diverticulitis de Meckel que presenta dolor abdominal tipo cólico, distensión abdominal y vómitos. Se procedió a la resección laparoscópica, con evolución favorable. Se obtuvo el diagnóstico por imágenes mediante estudio baritado y Tc abdominal

Carcinoid tumor in a Meckel's diverticulum: hypothesis on mutual embryological origin.

Congenital defects presenting at an adult age are subject to diagnostic errors because of their relative rarity and often odd clinical presentation. We illustrate a 63-year-old male patient with multiple ileal carcinoid tumors along with a carcinoid tumor in Meckel's diverticulum. The Meckel's diverticulum is a congenital abnormality arising from a patent vitelline duct and is found at the anti-mesenteric side of the ileum. In the Meckel's diverticulum, ectopic tissue or neoplasms are sometimes found, which may lead to intussusception, hemorrhage, or inflammation. The carcinoid tumor is a neuroendocrine neoplasm originating from the neural crest and is diagnosed at virtually all ages. It may exhibit malignant behavior but generally has a mild clinical course. It is most often found in endodermally derived organs, especially the digestive and pulmonary tracts, and coexists frequently with malignant tumors, predominantly of endodermal origin such as colorectal carcinoma. The carcinoid tumor and Meckel's diverticulum are known to coincide, whereas the carcinoid is not really considered to be an embryologically determined defect. We hypothesize that both lesions are derived from local erroneous interaction among the neural crest and the endoderm.

Repressive and restrictive mesodermal interactions with gut endoderm: possible relation to Meckel's Diverticulum.

The midgut and hindgut endoderm of the mouse embryo give rise to the intestinal epithelium, yet it is not known how the intestinal program is chosen in contrast to other endoderm-derived cell types. Previous tissue explant studies with embryos at 8.5 to 11.5 days gestation (d) showed that when the gut mesoderm is removed from the prospective intestinal endoderm, the endoderm activates the expression of liver-specific genes such as serum albumin, demonstrating the endoderm's pluripotence. This reversible repression of liver genes does not affect the expression of the endodermal transcription factors HNF3 and GATA4, nor these factors' ability to engage target sites in chromatin. We have now found that at 13.5 d, the mesoderm gains a second inhibitory activity, resulting in the irreversible loss of expression of HNF3 (Foxa2) and GATA factors in the endoderm and the absence of factors binding to their target sites in chromatin. The second inhibitory activity causes the endoderm to lose the potential to activate a liver gene, and this restriction precedes the normal cytodifferentiation of the intestinal epithelium. In summary, two inhibitory interactions with mesoderm successively restrict the developmental potential of the gut endoderm, leading to intestinal differentiation. We also observed rare gut bud structures in midgestation embryos that appear to represent murine examples of Meckel's Diverticulum, a congenital abnormality in human development. The absence of restrictive mesodermal interactions could explain how Meckel's diverticula express diverse non-intestinal, endoderm-derived cell types.

[Meckel's diverticulum. From embryology to therapy]. / Meckels divertikel. Fra embryologi til behandling.

Meckel's diverticulum (MD), an remnant of the omphalomesenteric duct, is the most common congenital abnormality of the small bowel. The aim of this paper is to give a review of MD, from embryology to diagnosis, complications and treatment.

Embryogenesis of a sac containing a Meckel's diverticulum.

The embryogenesis of a previously unreported mesothelial pouch containing a Meckel's diverticulum is presented.

Vesico-diverticular fistula: a rare complication of Meckel's diverticulum.

Enterovesical fistulas usually result from diverticulitis, Crohn's disease, or colorectal cancer. A perforated Meckel's diverticulum can also result in an vesico-diverticulum fistula, as noted in three previously reported cases. In all three cases, bladder or bowel disease was associated with the fistula. Herein, the authors describe a previously healthy, 23-year-old man who presented with an enterovesical fistula. Exploratory laparotomy revealed a vesico-diverticular fistula resulting from a perforated Meckel's diverticulum. Pathologic examination revealed that the diverticulum did not contain ectopic gastric or pancreatic tissue and that the perforation was secondary to an enterolith. The patient underwent a diverticulectomy and had an uneventful postoperative course. Unlike any of the three previously reported cases, the authors' patient had no coexisting bowel or bladder disease occurring with his vesico-diverticular fistula. To the authors' knowledge, this is only the third reported case of a vesico-diverticular fistula resulting from a perforated Meckel's diverticulum that did not contain ectopic tissue. It represents the first case where the perforation was secondary to an enterolith.

[Persistent ductus omphaloentericus as a cause of ileus in children]. / Perzistující ductus omphaloentericus jako prícina ileózního stavu u detí.

The authors describe a case of ileus in a 16-month-old child caused by Meckel's diverticulum. The symptoms leading to diagnosis were vague, partly masked by concurrent respiratory disease. In the discussion the authors mention possible complications associated with this anomaly.