The Embryology of Gut Rotation
ABSTRACT Until today, the puzzling spectrum of midgut "malrotations" is commonly explained by an "impaired" process of rotation of the midgut. However, a closer look at the literature reveals that the description of this "process of rotation" is rather schematic and is aimed more at explaining pathological findings, while detailed proper embryological investigations are still rare. Despite recent trials, good animals models that would allow the comparison of normal and abnormal midgut development are still missing. In the first part of this article, the "normal process of rotation," as it is described in the literature, is presented and critically analyzed. In general, it is a shortcoming that reliable illustrations of these crucial embryological processes are missing in most of these papers. Therefore, in the second part of this review scanning electron microscopy pictures of the developing midgut are presented in a series of rat embryos. In these pictures clear signs of a process of rotation are missing.
Full-textDOI: · Available from: Stefan Jaeschke-Melli, Sep 25, 2015
Click to see the full-text of:
Article: The Embryology of Gut Rotation
- SourceAvailable from: Philippe Soyer
- "After ten weeks, gut rotation results in the jejunum being positioned in the left side of the abdomen, which is the definitive location . An impaired process of rotation of the midgut results in the so-called malrotation with a right-sided jejunum, usually associated with a superior mesenteric artery on the right side of the superior mesenteric vein (Fig. 1)  . "
Article: MDCT and MR imaging of the jejunum[Show abstract] [Hide abstract]
ABSTRACT: Recent refinements in cross-sectional imaging have dramatically modified the investigation of the jejunum. Improvements in multidetector row computed tomography (MDCT) and magnetic resonance (MR) imaging technology have made detection and characterization of jejunal abnormalities easier. Current options include MDCT and MR imaging using either enterography or enteroclysis. The goal of this pictorial review is to outline the current imaging techniques that are used to investigate the jejunum and illustrate the most common conditions that affect this small bowel segment with a specific focus on MDCT and MR imaging using enterography or enteroclysis. MR imaging used in conjunction with optimal jejunal distension appears as the modality of choice for the diagnosis of a wide range of jejunal abnormalities. MDCT remains the first line imaging modalities because of an acute presentation in a substantial number of patients. Copyright © 2014 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.Diagnostic and interventional imaging 12/2014; 96(3). DOI:10.1016/j.diii.2014.11.008
[Show abstract] [Hide abstract]
- "To generate the final anatomical configuration of the mature gastrointestinal tract, the PGT undergoes dramatic elongation. In mammals, the midgut elongates so disproportionately that it must protrude into the umbilical stalk as the so-called ''physiological hernia'' (Kluth et al., 2003), before moving back into the visceral cavity during subsequent development. Likewise, the amphibian gut elongates more than three-fold in a single day, packaging its extensive length into concentric coils (Chalmers and Slack, 2000). "
ABSTRACT: During digestive organogenesis, the primitive gut tube (PGT) undergoes dramatic elongation and forms a lumen lined by a single-layer of epithelium. In Xenopus, endoderm cells in the core of the PGT rearrange during gut elongation, but the morphogenetic mechanisms controlling their reorganization are undetermined. Here, we define the dynamic changes in endoderm cell shape, polarity, and tissue architecture that underlie Xenopus gut morphogenesis. Gut endoderm cells intercalate radially, between their anterior and posterior neighbors, transforming the nearly solid endoderm core into a single layer of epithelium while concomitantly eliciting "radially convergent" extension within the gut walls. Inhibition of Rho/ROCK/Myosin II activity prevents endoderm rearrangements and consequently perturbs both gut elongation and digestive epithelial morphogenesis. Our results suggest that the cellular and molecular events driving tissue elongation in the PGT are mechanistically analogous to those that function during gastrulation, but occur within a novel cylindrical geometry to generate an epithelial-lined tube.Developmental Dynamics 12/2009; 238(12):3111-25. DOI:10.1002/dvdy.22157 · 2.38 Impact Factor
[Show abstract] [Hide abstract]
- "Reduction and rotation are completed by the tenth week of gestation and result in the prearterial segment localized below and to the left of the SMA while the postarterial segment lies superior and to the right. Lastly, the mesenteries of the ascending and descending colons become fused to the posterior parietal peritoneum, and the root of the small bowel mesentery, containing the SMA, extends obliquely from the left side of the second lumbar vertebra toward the right sacroiliac joint.16,17 "
ABSTRACT: Right paraduodenal hernia (PDH) results from a primitive gut malrotation. The resultant jejunal mesenteric defect posterior to the superior mesenteric vessels allows decompressed jejunum to herniate retroperitoneally. PDH make up 53% of all internal hernias, but account for only 0.2% to 5.8% of all cases of intestinal obstruction. In addition, PDH exhibits male and left-sided predominance. Ours is the second report to describe the preoperative diagnosis and totally laparoscopic repair of a right PDH. We report the case of a 26-year-old female with symptoms suggestive of partial small bowel obstruction and a 6-year history of intermittent abdominal pain. Physical examination demonstrated lower quadrant tenderness. Plain abdominal radiographs and ultrasonography were nondiagnostic. Contrasted computed tomography of the abdomen revealed jejunum encased within the right upper quadrant suspicious for right PDH. The patient underwent successful laparoscopic right PDH repair and was discharged home on postoperative day 1 without late sequelae. In the outpatient setting, clinical suspicion and comprehensive radiological investigation permit preoperative diagnosis of right PDH. In acute situations, clinical presentation, plain radiographs, and then diagnostic laparoscopy may be an expeditious diagnostic algorithm. Subsequent laparoscopic repair of right PDH is feasible and may shorten hospital length of stay.JSLS: Journal of the Society of Laparoendoscopic Surgeons / Society of Laparoendoscopic Surgeons 04/2009; 13(2):242-9. · 0.91 Impact Factor