Gastrointestinal Tract - Abnormalities

From Embryology

Introduction

The "simple tube" of the gastrointestinal tract and its associated organs have many different tract and organ specific abnormalities. Note that as this system begins function (digestively) postnatally, unless there is a determined genetic history within the family, several abnormalities only become evident postnatally. Due to the complex nature (different germ layer contributions, organogenisis) of the growth, elongation and folding of the tract, there are also several mechanical disorders of folding (rotation).

GIT Links: Introduction | Medicine Lecture | Science Lecture | endoderm | mouth | oesophagus | stomach | liver | gallbladder | Pancreas | intestine | mesentery | tongue | taste | enteric nervous system | Stage 13 | Stage 22 | gastrointestinal abnormalities | Movies | Postnatal | milk | tooth | salivary gland | BGD Lecture | BGD Practical | GIT Terms | Category:Gastrointestinal Tract
GIT Histology Links: Upper GIT | Salivary Gland | Smooth Muscle Histology | Liver | Gallbladder | Pancreas | Colon | Histology Stains | Histology | GIT Development
Historic Embryology - Gastrointestinal Tract  
1878 Alimentary Canal | 1882 The Organs of the Inner Germ-Layer The Alimentary Tube with its Appended Organs | 1884 Great omentum and transverse mesocolon | 1902 Meckel's diverticulum | 1902 The Organs of Digestion | 1903 Submaxillary Gland | 1906 Liver | 1907 Development of the Digestive System | 1907 Atlas | 1907 23 Somite Embryo | 1908 Liver | 1908 Liver and Vascular | 1910 Mucous membrane Oesophagus to Small Intestine | 1910 Large intestine and Vermiform process | 1911-13 Intestine and Peritoneum - Part 1 | Part 2 | Part 3 | Part 5 | Part 6 | 1912 Digestive Tract | 1912 Stomach | 1914 Digestive Tract | 1914 Intestines | 1914 Rectum | 1915 Pharynx | 1915 Intestinal Rotation | 1917 Entodermal Canal | 1918 Anatomy | 1921 Alimentary Tube | 1932 Gall Bladder | 1939 Alimentary Canal Looping | 1940 Duodenum anomalies | 2008 Liver | 2016 GIT Notes | Historic Disclaimer
Human Embryo: 1908 13-14 Somite Embryo | 1921 Liver Suspensory Ligament | 1926 22 Somite Embryo | 1907 23 Somite Embryo | 1937 25 Somite Embryo | 1914 27 Somite Embryo | 1914 Week 7 Embryo
Animal Development: 1913 Chicken | 1951 Frog

| original page

Australian Statistics

Australian abnormalities 81-92 git.jpg The pie diagram shows the relative contribution of major gastrointestinal tract abnormalities as a percentage of the total number of congenital abnormalities in Australia beween 1981 - 92.

Note that the digestive system represents approximately 6% of all major congenital abnormalities.

One of the most common abnormalities occurring in (2% - 3% population) is Meckel's Diverticulum.

The mouth (cleft lip, cleft palate) is part of the digestive tract, but more accurately reflects an abnormality of face formation.

Data shown as a percentage of all major abnormalities based upon published statistics using the same groupings as Congenital Malformations Australia 1981-1992 P. Lancaster and E. Pedisich ISSN 1321-8352.

Some Recent Findings

  • Hedgehog/Notch-induced premature gliogenesis represents a new disease mechanism for Hirschsprung disease in mice and humans PMID 21841314 "Hirschsprung (HSCR) disease is a complex genetic disorder attributed to a failure of the enteric neural crest cells (ENCCs) to form ganglia in the hindgut. Hedgehog and Notch are implicated in mediating proliferation and differentiation of ENCCs. Nevertheless, how these signaling molecules may interact to mediate gut colonization by ENCCs and contribute to a primary etiology for HSCR are not known. Here, we report our pathway-based epistasis analysis of data generated by a genome-wide association study on HSCR disease, which indicates that specific genotype constellations of Patched (PTCH1) (which encodes a receptor for Hedgehog) and delta-like 3 (DLL3) (which encodes a receptor for Notch) SNPs confer higher risk to HSCR. Importantly, deletion of Ptch1 in mouse ENCCs induced robust Dll1 expression and activation of the Notch pathway, leading to premature gliogenesis and reduction of ENCC progenitors in mutant bowels. Dll1 integrated Hedgehog and Notch pathways to coordinate neuronal and glial cell differentiation during enteric nervous system development. In addition, Hedgehog-mediated gliogenesis was found to be highly conserved, such that Hedgehog was consistently able to promote gliogenesis of human neural crest-related precursors. Collectively, we defined PTCH1 and DLL3 as HSCR susceptibility genes and suggest that Hedgehog/Notch-induced premature gliogenesis may represent a new disease mechanism for HSCR."

GIT Lumen Abnormalities

Gastrointestinal tract duplication sites based upon 78 clinical studies.[1]

There are several types of abnormalities (atresia, stenosis and duplication) that impact upon the continuity of the gastrointestinal tract lumen.

Atresia

An interruption of the lumen (esophageal atresia, duodenal atresia, extrahepatic biliary atresia, anorectal atresia)

  • Pyloric atresia (PA) - a very rare condition (incidence 1 in 100,000 newborns) and about 1% of all intestinal atresias.

Stenosis

A narrowing of the lumen (duodenal stenosis, pyloric stenosis)

Duplication

An incomplete recanalization resulting in parallel lumens, this is really a specialized form of stenosis.

Links: Image - small intestine duplication

Intestinal Malrotation

Intestinal malrotation.jpg Presents clinically in symptomatic malrotation as:

Neonates - bilious vomiting and bloody stools.

Newborn - bilious vomiting and failure to thrive.

Infants - recurrent abdominal pain, intestinal obstruction, malabsorption/diarrhea, peritonitis/septic shock, solid food intolerance, common bile duct obstruction, abdominal distention, and failure to thrive.

Ladd's Bands - are a series of bands crossing the duodenum which can cause duodenal obstruction.

Volvulus

Twisting of the midgut (bowel) which causes obstruction to the flow of material. Can include a variable loss of local blood supply which leads to tissue death.


Midgut volvulus.jpg Cecal volvulus.jpg Sigmoid volvulus.jpg

Diagnosis is generally by upper gastrointestinal radiologic examination or less frequently by barium enema or CT scan.

Corrective surgery is generally by the Ladd's procedure, even with surgical treatment there is still significant associated complications and long-term morbidity.

What abnormal embryological processes could interfere with normal rotation and fixation of the gut?

Search PubMed: intestinal+malrotation

OMIM: Volvulus of Midgut

Links: Medlineplus - childhood volvulus | AAFP - Bilious Vomiting in the Newborn | Pediatric education - Neonatal Bilious Emesis |

Situs Inversus Viscera

Disturbance of the lateralisation of the liver may produce transposition of some or all of the foregut and its derivatives.

  • Stomach
  • Pancreas
  • Duodenum - jejunum
  • Spleen
  • Bile

Also in situs inversus the anatomical relations of the duodenum, pancreas, bile ducts and portal veins may be reversed or disordered.

Search PubMed: Situs Inversus Viscera

Meckel's Diverticulum

Meckel's diverticulum 01.jpgMeckel's diverticulum 02.jpgMeckel's diverticulum 03.jpg

This GIT abnormality is a very common and results from improper closure and absorption of the omphalomesenteric duct (vitelline duct) in development. This transient developmental duct connects the yolk to the primitive gastrointestinal tract.

In addition to Meckel's diverticulum there are a range of other vitelline duct abnormalities, which depend on the degree from a completely patent duct at the umbilicus to lesser remnants (cysts, fibrous cords connecting umbilicus to distal ileum, granulation tissue at umbilicus, or umbilical hernias).



Links: OMIM - Meckel's Diverticulum Pubmed - Meckel's Diverticulum | Pubmed - omphalomesenteric duct | Pubmed - vitelline duct |

Intestinal Aganglionosis

(intestinal aganglionosis, Hirschsprung's disease, aganglionic colon, megacolon, congenital aganglionic megacolon, congenital megacolon) A condition caused by the lack of enteric nervous system (neural ganglia) in the intestinal tract responsible for gastric motility (peristalsis). In general, its severity is dependent upon the amount of the GIT that lacks intrinsic ganglia, due to developmental lack of neural crest migration into those segments. (More? Neural Crest System - Abnormalities)

Historically, Hirschsprung's disease takes its name from Dr Harald Hirschsprung (1830-1916) a Danish pediatrician (of German extraction). In 1886, he presented at the German Society of Pediatrics conference in Berlin a case of 2 infants who died of complications of bowel obstruction (H. Hirschsprung, Stuhltragheit Neugeborener in Folge von Dilatation und Hypertrophie des Colons, Jhrb f Kinderh 27 (1888), pp. 1-7). Later autopsies identified a dilatation and hypertrophy of large intestine, and the rectum appeared normally narrow. Hirschsprung suggested that the condition was an inborn disease and named it congenital megacolon.

The first indication in newborns is an absence of the first bowel movement, other symptoms include throwing up and intestinal infections. Clinically this is detected by one or more tests (barium enema and x ray, manometry or biopsy) and can currently only be treated by surgery. A temoporary ostomy (Colostomy or Ileostomy) with a stoma is carried out prior to a more permanent pull-through surgery.


Megacolon stoma1.jpg Megacolon stoma2.jpg  
Ostomy - Aganglionic portion removed Stoma - intestine attached to the abdomen wall
Megacolon surgery 01.jpg Megacolon surgery 02.jpg Megacolon surgery 03.jpg
Short section of the colon without smooth muscle neural ganglia Aganglionic segment removed Reattachment


Images: NIH - NIDDK - Hirschsprungs


Links: Neural Crest System - Abnormalities | NIH - NIDDK - Hirschsprungs | MedlinePlus - Hirschsprung's disease | Search PubMed

Gastroschisis

Gastroschisis (paraomphalocele, laparoschisis, abdominoschisis, abdominal hernia) is an abdominal wall defect associated with evisceration of the intestine (2.5 cases/10,000 births), occuring more frequently in young mothers (less than 20 years old). There have been reports that this abnormality is increasing in incidence.

International Classification of Diseases, 9th Revision diagnosis (756.79) and procedure (54.71) code for gastroschisis (2003 to 2008).

The abnormality is usually situated to the right of the umbilicus and abdominal contents, mainly gastrointestinal, are found outside the anterior body wall. Can occur in isolation and also in association with other gastrointestinal anomalies (intestinal atresia, perforation, necrosis or volvulus). Defects in other organ systems have been reported in up to 35% of children. There are several theories as to the cause of this abdominal wall defect, including recently failure of the yolk sac and related vitelline structures to be incorporated into the umbilical stalk.[2] The condition can often be detected by ultrasound scan. Reported as a high mortality defect, only 60% of children survive until the end of the first year of age.

Gastroschisis 01.jpg

Gastroschisis Ultrasound Quicktime | Flash

Links: Ultrasound movie - Gastroschisis | UCSF Childrens Hospital - Gastroschisis | Brown University Image Bank- Abdominal Wall Defects

Omphalocele

The omphalocele, pubic diastasis, loss of pubic bones and polydactyly in Gli3Xt; Alx4Lst; Shh combinatorial mutants.[3]

An abnormality appearing similar to gastroschisis, involves "covered by membranes" and a lack of normal return of the bowel to the abdominal cavity and has a different position relative to the umbilical cord.

  • omphalocele - herniation of the bowel, liver and other organs into the intact umbilical cord, the tissues being covered by membranes unless the latter are ruptured
  • gastroschisis - intact umbilical cord and evisceration of the bowel through a defect in the abdominal wall, generally to the right of the cord, with no membrane covering

Short-Bowel Syndrome

Not generally a developmental abnormality, but related to therapeutic intervention in GIT abnormalities or disease.

Short bowel syndrome is a group of problems affecting people who have had half or more of their small intestine removed. The most common reason for removing part of the small intestine is to treat Crohn's disease. Short bowel syndrome is treated through changes in diet, intravenous feeding, vitamin and mineral supplements, and medicine to relieve symptoms. (NDDIC)


Links: Better Health Short Bowel syndrome | National Digestive Diseases Information Clearinghouse Short Bowel syndrome

Obstetric Cholestasis

A recent paper in the British Medical Journal discusses this pregnancy associated disease.

"Obstetric cholestasis (or intrahepatic cholestasis of pregnancy) remains widely disregarded as an important clinical problem, with many obstetricians still considering its main symptom, pruritus, a natural association of pregnancy. Obstetric cholestasis is associated with cholesterol gallstones. It may be extremely stressful for the mother but also carries risks for the baby." Piotr Milkiewicz, Elwyn Elias, Catherine Williamson, and Judith Weaver BMJ 2002; 324: 123-124

Small Bowel Obstruction

The are two major forms of small bowel obstruction are from either external (extrinsic) or internal (intrinsic) causes. (More? see [#11353110 Boudiaf etal., 2001]) Listed below are a few examples of both causes.

Extrinsic Causes - adhesions, closed loop, strangulation, hernia and extrinsic masses

Intrinsic Causes - intestinal malrotation, Crohn disease, adenocarcinoma, tuberculosis, radiation enteropathy, intramural hemorrhage, intussusception and intraluminal causes.

Necrotizing Enterocolitis

Necrotizing enterocolitis (NE) is the death of intestinal tissue that occurs postnatally in mainly in premature and low birth weight infants (1 in 2,000 - 4,000 births). The underdeveloped gastointestinal tract appears to be susceptible to bacteria, normally found within the tract,to spread widely to other regions where they damage the tract wall and may enter the bloodstream.

Those with a higher risk for this condition include:

  • Premature infants
  • Infants who are fed concentrated formulas
  • Infants in a nursery where an outbreak has occurred
  • Infants who have received blood exchange transfusions


Links: Medline Plus - Necrotizing Enterocolitis | Kids Health - Necrotizing Enterocolitis |

Meconium Plug Syndrome

(functional immaturity of the colon) Term used to describe a transient disorder of the newborn colon, which is characterized by delayed passage of meconium (more than 24 to 48 h), intestinal dilatation and yellow/green vomiting. More common in premature infants and can be determined by radiological dye study.

A recent study by Keckler etal., 2008 looked at thecorrelation of meconium plug as identified radiologically covering 1994 to 2007, of 77 patients (mean gestational age 37.4 weeks, birth weight, 2977 g) Hirschsprung's disease was found in 10 patients (13%). "Although all patients with plugs and persistent abnormal stooling patterns should prompt a rectal biopsy and genetic probe, the incidence of Hirschsprung's and cystic fibrosis may not be as high as previously reported."


Links: Keckler SJ, St Peter SD, Spilde TL, Tsao K, Ostlie DJ, Holcomb GW 3rd, Snyder CL. Current significance of meconium plug syndrome. J Pediatr Surg. 2008 May;43(5):896-8.PMID: 18485962 | U Mich - Meconium Plug Syndrome |

Appendix Duplication

Appendix duplication is an extremely rare congenital anomaly (0.004% to 0.009% of appendectomy specimens) first classified according to their anatomic location by Cave in 1936[4] and a later modified by Wallbridge in 1963[5], subsequently two more types of appendix abnormalities have been identified.[6][7]

Modified Cave-Wallbridge Classification (table from[8])

Classification of types
of appendix duplication
Features
A Single cecum with various degrees of incomplete duplication
B1 (bird type) Two appendixes symmetrically placed on either side of the ileocecal valve
B2 (tenia coli type) ne appendix arises from the cecum at the usual site, and the second

appendix branches from the cecum along the lines of the tenia at various distances from the first

B3 One appendix arises from the usual site, and the second appendix arises from

the hepatic flexura

B4 One appendix arises from the usual site, and the second appendix arises from

the splenic flexura

C Double cecum, each with an appendix
Horseshoe appendix One appendix has two openings into a common cecum
Triple appendix One appendix arises from the cecum at the usual site, and two additional appendixes arise from the colon

Anorectal Malformations

(ARMs) A group of many different abnormalities that can involve the distal anus and rectum as well as the urinary and genital tracts, for review see[9]. Occurring with an incidence of approximately 1 in 5000 live births.

Classification of non-syndromic anorectal malformations (ARM)

Males
Recto-perineal fistula

Recto-urethral-bulbar fistula

Recto-urethral-prostatic fistula

Recto-bladderneck fistula

Imperforated anus without fistula

Complex and unusual defects

Females
Recto-perineal fistula

Recto-vestibular fistula

Cloaca with short common channel (< 3 cm)

Cloaca with long common channel (> 3 cm)

Imperforated anus without fistula

Complex and unusual defects
Cloacal extrophy, covered cloacal extra

Posterior cloaca

Associated to presacral mass

Rectal atresia

Table Levitt and Peña (2007)[9]


=Anal Atresia

Anal atresia or imperforate anus is an abnormality of incomplete anorectal region development occurring in about 1 in 5,000 infants. Resulting in accumulation of and failure of stool cannot pass out of the colon.

  • rectum may end and not connect with the anus
  • rectum may connect anatomically to the wrong region (urethra, bladder, or vagina).
  • anus may be very narrowed or missing altogether.

Congenital Cloaca

Anal muscles and vagina wall do not form leading to a variable opening composing all or some of the rectum, vagina and bladder. Surgically requires a colostomy and other procedures to transfers a muscle from another part of the body to create a functioning sphincter at the anus.

References

  1. <pubmed>718292</pubmed>
  2. <pubmed>19419415</pubmed>
  3. <pubmed>21283718</pubmed>| PMC3024424 | PLoS One.
  4. <pubmed>17104589</pubmed>
  5. <pubmed>13998581</pubmed>
  6. <pubmed>2772830</pubmed>
  7. <pubmed>5635427</pubmed>
  8. <pubmed>21513538</pubmed>| J Medical Case Reports | PDF
  9. 9.0 9.1 <pubmed>17651510</pubmed>

Reviews

<pubmed>20549505</pubmed>| PMC2908440 <pubmed>15378215</pubmed> <pubmed>15026601</pubmed> <pubmed>12738470</pubmed> <pubmed>11826631</pubmed> <pubmed>11353110</pubmed>

Articles

<pubmed>19419414</pubmed> <pubmed>17230493</pubmed> <pubmed>16465538</pubmed> <pubmed>16390394</pubmed> <pubmed>16205928</pubmed> <pubmed>16563666</pubmed> <pubmed>15793730</pubmed> <pubmed>15488122</pubmed> <pubmed>12557047</pubmed>

Search PubMed

Search Pubmed: gastrointestinal tract abnormalities | intestinal malrotation | Situs Inversus Viscera | Gastroschisis | Intestinal Aganglionosis

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Cite this page: Hill, M.A. (2024, May 5) Embryology Gastrointestinal Tract - Abnormalities. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Gastrointestinal_Tract_-_Abnormalities

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