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==Overview==
==Overview==
Regardless of cause, volvulus causes symptoms by two mechanisms.  One is [[bowel obstruction]], manifested as [[abdominal distension]] and [[vomiting]]. The other is [[ischemia]] (loss of blood flow) to the affected portion of [[intestine]].  This causes severe [[pain]] and progressive injury to the [[intestinal wall]], with accumulation of gas and fluid in the portion of the bowel obstructed. Ultimately, this can result in [[necrosis]] of the affected [[intestinal wall]], [[acidosis]], and [[death]]. Acute volvulus therefore requires immediate surgical intervention to untwist the affected segment of bowel and possibly [[bowel resection|resect]] any unsalvageable portion.
Regardless of cause, volvulus causes symptoms by two mechanisms: One is [[bowel obstruction]], manifested as [[abdominal distension]] and [[vomiting]]. The other is [[ischemia]] (loss of blood flow) to the affected portion of [[intestine]].  This causes severe [[pain]] and progressive injury to the [[intestinal wall]], with accumulation of gas and fluid in the portion of the bowel obstructed. Ultimately, this can result in [[necrosis]] of the affected [[intestinal wall]], [[acidosis]], and [[death]]. Acute volvulus therefore requires immediate surgical intervention to untwist the affected segment of bowel and possibly [[bowel resection|resect]] any unsalvageable portion.
 
==Pathophysiology==
==Pathophysiology==
*The twisting of a mobile loop of bowel can happen spontaneously and may be congenital or acquired.
===Ileal and Sigmoid Volvulus===
*The mesentery anchors the ileum and sigmoid colon to the abdominal wall.<ref name="pmid5781046">{{cite journal |vauthors=Shepherd JJ |title=The epidemiology and clinical presentation of sigmoid volvulus |journal=Br J Surg |volume=56 |issue=5 |pages=353–9 |year=1969 |pmid=5781046 |doi= |url=}}</ref><ref name="pmid7387365">{{cite journal |vauthors=VerSteeg KR, Whitehead WA |title=Ileosigmoid knot |journal=Arch Surg |volume=115 |issue=6 |pages=761–3 |year=1980 |pmid=7387365 |doi= |url=}}</ref>
*An air filled loop of the sigmoid colon or the ileum, sometimes, twists itself about the axis of the mesentery.
*The incidence of volvulus occurring increases with a redundant or longer than normal mesentery.
*If the degree of twisting is beyond 180 - 360 degress, then the bowel loop will become obstructed and ischemia will begin.
*Ileosigmoid knotting is a variant of sigmoid volvulus where the ileum wraps around the sigmoid in a clockwise direction.
===Gastric Volvulus===
*Normally, there are ligaments such as the gastrocolic, gastrohepatic, gastrosplenic and gastrophrenic ligaments that keeps the stomach in place by attaching it to other abdominal organs and the diaphragm.<ref name="pmid19900595">{{cite journal |vauthors=Rashid F, Thangarajah T, Mulvey D, Larvin M, Iftikhar SY |title=A review article on gastric volvulus: a challenge to diagnosis and management |journal=Int J Surg |volume=8 |issue=1 |pages=18–24 |year=2010 |pmid=19900595 |doi=10.1016/j.ijsu.2009.11.002 |url=}}</ref><ref name="pmid12823923">{{cite journal |vauthors=Shivanand G, Seema S, Srivastava DN, Pande GK, Sahni P, Prasad R, Ramachandra N |title=Gastric volvulus: acute and chronic presentation |journal=Clin Imaging |volume=27 |issue=4 |pages=265–8 |year=2003 |pmid=12823923 |doi= |url=}}</ref>
*However, the stomach can twist around its horizontal or vertical axis.
*Gastric outlet obstruction may occur as a result of abnormal rotation more than 180 degrees.
*Chronic rotation can cause bleeding  by decreasing venous return and increasing capillary pressure.
===Cecal Volvulus===
There are three types of cecal volvulus, type I and II are the most common, type III account for the remaining 20% of cases:
*Type I
**The cecum twists in a clockwise manner along its axis.
**The cecum fills with air and remains in right lower quadrant.
*Type II
**The cecum and a proximal part of the ileum twist in a counterclockwise direction.
**The cecum becomes inverted and is relocated to the left lower quadrant.
*Type III
**The cecum folds upwards and back on itself rather than rotating along its axis.
●Congenital mobile cecum is hypothesized to result from failed fusion of the ascending colon mesentery to the posterior parietal peritoneum [15]. Based upon autopsy studies, approximately 10 to 25 percent of the population have a cecum and ascending colon with sufficient mobility to develop a volvulus [16]. A congenital mobile cecum can also cause mobile cecum syndrome [17]. (See 'Differential diagnosis' below.)
●Acquired anatomic abnormalities, such as adhesions from abdominal surgery, can also contribute to the development of a cecal volvulus. Other clinical settings that have been associated with cecal volvulus include pregnancy [18], colonic atony, colonoscopy [19], and Hirschsprung's disease [20].


*In western society, chronic [[constipation]] can lead to an overloaded [[sigmoid colon]].
*In developing nations, a high [[Dietary fiber|fiber]] diet leads to sigmoidal overload.
*When the bowel loop is overloaded with material, it becomes susceptible to torsion along the axis of an elongated [[mesentery]].
*A large pelvic mass or a large gravid uterus can alter the position of the intra-abdominal organs, predisposing to the formation of volvulus.
*With recurrent attacks of torsion, the base of the [[mesentery]] can become chronically inflammed and eventually shortens.
*This leads to recurrent volvulus.
*The twisting of a mobile loop of bowel can happen spontaneously and may be [[Congenital disorder|congenital]] or [[Acquired disorder|acquired]].
*[[Acquired disorder|Acquired]] causes of volvulus include:<ref name="pmid8781706">{{cite journal |vauthors=John H, Gyr T, Giudici G, Martinoli S, Marx A |title=Cecal volvulus in pregnancy. Case report and review of literature |journal=Arch. Gynecol. Obstet. |volume=258 |issue=3 |pages=161–4 |year=1996 |pmid=8781706 |doi= |url=}}</ref><ref name="pmid3943670">{{cite journal |vauthors=Radin DR, Halls JM |title=Cecal volvulus: a complication of colonoscopy |journal=Gastrointest Radiol |volume=11 |issue=1 |pages=110–1 |year=1986 |pmid=3943670 |doi=10.1007/BF02035046 |url=}}</ref><ref name="pmid9021588">{{cite journal |vauthors=Sarioğlu A, Tanyel FC, Büyükpamukçu N, Hiçsönmez A |title=Colonic volvulus: a rare presentation of Hirschsprung's disease |journal=J. Pediatr. Surg. |volume=32 |issue=1 |pages=117–8 |year=1997 |pmid=9021588 |doi= |url=}}</ref>
**[[Adhesion (medicine)|Adhesions]]
**[[Iatrogenic disorder|Iatrogenic]] e.g. lower GI endoscopy
**Bowel [[atony]]
**[[Hirschsprung's disease]]
**[[Pregnancy]]
*[[Congenital disorder|Congenital]] causes are discussed below.


===Intestinal Malrotation in Neonates and Infants ===
===Intestinal Malrotation in Neonates and Infants ===
====Embryology====
*[[Intestinal malrotation|Malrotation]] occurs when there is arrest of the normal rotation of the embryonic gut.<ref name="pmid26205079">{{cite journal |vauthors=Graziano K, Islam S, Dasgupta R, Lopez ME, Austin M, Chen LE, Goldin A, Downard CD, Renaud E, Abdullah F |title=Asymptomatic malrotation: Diagnosis and surgical management: An American Pediatric Surgical Association outcomes and evidence based practice committee systematic review |journal=J. Pediatr. Surg. |volume=50 |issue=10 |pages=1783–90 |year=2015 |pmid=26205079 |doi=10.1016/j.jpedsurg.2015.06.019 |url=}}</ref><ref name="pmid19369837">{{cite journal |vauthors=Diaz MC, Reichard K, Taylor AA |title=Intestinal nonrotation in an adolescent |journal=Pediatr Emerg Care |volume=25 |issue=4 |pages=249–51 |year=2009 |pmid=19369837 |doi=10.1097/PEC.0b013e31819e36aa |url=}}</ref>
*During  weeks 4-8 of development, the embryonic [[coelom]], or cavity, normally cannot accommodate the rapidly expanding gastrointestinal (GI) tract.
*Consequently, the primary intestinal loop pushes back into the yolk stalk, and will become the future [[umbilicus]].
*The direction in which the loop grows takes the axis of the future [[superior mesenteric artery]].
*As the primary intestinal loop grows out of the abdomen, it begins to rotate by twisting 90 degrees counterclockwise.
*There are two factors that force this rotation:
**The proximal bowel (gastroduodenal) grows faster than the distal bowel (cecocolic).
**The liver has rapidly develops.
*During weeks 8 - 10, the primary intestinal loop continues to grow and returns back into the abdomen cavity and a further 180 degree counterclockwise rotation occurs.
*Overall, the primary loop twists a total of 270 degrees in a counterclockwise direction.
*Once the primary loop is in its final position, fixation to the posterior abdominal wall begins.
*The proximal bowel portion including the [[stomach]] and [[duodenum]] are fixated early in gestation through the [[ligament of Treitz]].
*The [[Colon (anatomy)|colon]] takes a longer time to become fixated and usually, fixation is completed near term.


EMBRYOLOGY AND PATHOGENESIS — Intestinal malrotation occurs as a result of an arrest of normal rotation of the embryonic gut. (See "Overview of the development of the gastrointestinal tract".)
===Pathophysiology of Infantile and Neonatal Volvulus===
*Normal gut development means that:<ref name="Burns2006">{{cite journal|last1=Burns|first1=Cartland|title=Principles and Practices of Pediatric Surgery|journal=Annals of Surgery|volume=243|issue=4|year=2006|pages=567|issn=0003-4932|doi=10.1097/01.sla.0000208423.52007.38}}</ref>
**A wide-based [[mesentery]] will extend from the [[ligament of Treitz]] in the left upper quadrant to the [[ileocecal valve]] in the right lower quadrant.
**The primary loop will continue its rotation upon return to the abdominal cavity.
**Both proximal (duodenojejunal) and distal (cecocolic) limbs rotate at the same rate and to the same degree.
*Congenital volvulus happens when the following anomalies have occurred:
**Narrow [[Mesentery|mesenteric]] base:
***The midgut becomes suspended by a narrow pedicle.
**Non-rotation:
***In non-rotation, the primary loop undergoes no further rotation during its return to the abdominal cavity.
***The small bowel becomes located on the right whilst the [[colon]] is on the left of the abdomen.
***Non-rotation is less dangerous than malrotation because in non-rotation, the [[mesentery]] is wider and the risk of volvulus is lower.
**Malrotation:
***In malrotation, the proximal (duodenojejunal) limb remains in a position of non-rotation, and the distal (cecocolic) limb partially rotates (usually only 90 degrees instead of 180 degrees).
***Consequently,the [[cecum]] is relocated to the mid-upper abdomen, instead of the right lower quadrant.
***The abnormally-positioned [[cecum]] is attached by bands of [[peritoneum]] (Ladd bands) to the right lateral abdominal wall.
***Ladd bands can cause compression and obstruction of the duodenum extrinsically.


●Embryology – During the fourth to eighth week of embryonic development, the embryonic coelom, or cavity, cannot accommodate the rapidly expanding gastrointestinal (GI) tract. As a result, the primary intestinal loop buckles into the area of the yolk stalk, which will be the future umbilicus. The axis of this loop is the developing superior mesenteric artery (SMA). As the primary intestinal loop buckles out of the abdomen, it begins the normal rotation of the bowel by twisting 90 degrees counterclockwise (figure 1 and figure 2). This initial rotation is driven by two factors [1]:
*Other anomalies of rotation can rarely occur, these include:
**Rotation of the proximal (duodenojejunal) limb is reversed resulting in a [[duodenum]] that is located anterior to the [[superior mesenteric artery]].
**Rotation of the distal (cecocolic) limb is reversed resulting in a [[transverse colon]] that is located posterior to the [[superior mesenteric artery]].
**Finally, a combination of reversed rotation of the proximal (duodenojejunal) limb with normal rotation of the distal (cecocolic) limb can lead to a paraduodenal [[hernia]].  
***In this anomaly, anterior to the [[superior mesenteric artery]] lies the [[duodenum]]. Anterior to the [[duodenum]], the distal (cecocolic) limb rotates normally.
***The [[mesentery]] of the right [[Colon (anatomy)|colon]] creates a pouch, the [[Small intestine|small bowel]] then herniates into it.


•The proximal bowel (the "prearterial" or duodenojejunal loop) grows faster than the distal bowel (the "postarterial" or cecocolic loop), and
===Ileal and Sigmoid Volvulus===
*The [[mesentery]] anchors the [[ileum]] and [[sigmoid colon]] to the posterior abdominal wall.<ref name="pmid5781046">{{cite journal |vauthors=Shepherd JJ |title=The epidemiology and clinical presentation of sigmoid volvulus |journal=Br J Surg |volume=56 |issue=5 |pages=353–9 |year=1969 |pmid=5781046 |doi= |url=}}</ref><ref name="pmid7387365">{{cite journal |vauthors=VerSteeg KR, Whitehead WA |title=Ileosigmoid knot |journal=Arch Surg |volume=115 |issue=6 |pages=761–3 |year=1980 |pmid=7387365 |doi= |url=}}</ref>
*An air filled loop of the [[sigmoid colon]] or the terminal [[ileum]], sometimes, twists itself about the axis of the [[mesentery]].
*The incidence of volvulus occurring increases with a redundant or longer than normal [[mesentery]].
*If the degree of twisting is beyond 180 - 360 degress, then the bowel loop will become obstructed and [[ischemia]] will develop.
*Ileosigmoid knotting is a variant of [[Sigmoid colon|sigmoid]] volvulus where the [[ileum]] wraps around the [[Sigmoid colon|sigmoid]] in a clockwise direction.


•The rapid growth of the liver.
===Gastric Volvulus===
*Normally, there are ligaments such as the [[Gastrocolic ligament|gastrocolic]], gastrohepatic, [[Gastrosplenic ligament|gastrosplenic]] and [[Gastrophrenic ligament|gastrophrenic]] ligaments that keeps the [[stomach]] in place by attaching it to other abdominal organs and the [[Thoracic diaphragm|diaphragm]].<ref name="pmid19900595">{{cite journal |vauthors=Rashid F, Thangarajah T, Mulvey D, Larvin M, Iftikhar SY |title=A review article on gastric volvulus: a challenge to diagnosis and management |journal=Int J Surg |volume=8 |issue=1 |pages=18–24 |year=2010 |pmid=19900595 |doi=10.1016/j.ijsu.2009.11.002 |url=}}</ref><ref name="pmid12823923">{{cite journal |vauthors=Shivanand G, Seema S, Srivastava DN, Pande GK, Sahni P, Prasad R, Ramachandra N |title=Gastric volvulus: acute and chronic presentation |journal=Clin Imaging |volume=27 |issue=4 |pages=265–8 |year=2003 |pmid=12823923 |doi= |url=}}</ref>
*However, the [[stomach]] can twist around its horizontal or vertical axis.
*Gastric outlet obstruction may occur as a result of abnormal rotation more than 180 degrees.
*Chronic rotation can cause bleeding  by decreasing [[venous return]] and increasing capillary pressure.


The primary loop continues to grow, and then returns to the abdomen during the 8th to 10th week of gestation. With the return to the abdomen, there is an additional 180 degrees counterclockwise rotation. The overall effect is that the bowel rotates 270 degrees counterclockwise from the original primary loop (figure 1 and figure 2).
===Cecal Volvulus===
 
*The [[cecum]] is especially liable to being mobile congenitally.<ref name="pmid7807358">{{cite journal |vauthors=Husain K, Fitzgerald P, Lau G |title=Cecal volvulus in the Cornelia de Lange syndrome |journal=J. Pediatr. Surg. |volume=29 |issue=9 |pages=1245–7 |year=1994 |pmid=7807358 |doi= |url=}}</ref><ref name="pmid18111729">{{cite journal |vauthors=DONHAUSER JL, ATWELL S |title=Volvulus of the cecum with a review of 100 cases in the literature and a report of six new cases |journal=Arch Surg |volume=58 |issue=2 |pages=129–48 |year=1949 |pmid=18111729 |doi= |url=}}</ref><ref name="pmid6734364">{{cite journal |vauthors=Rogers RL, Harford FJ |title=Mobile cecum syndrome |journal=Dis. Colon Rectum |volume=27 |issue=6 |pages=399–402 |year=1984 |pmid=6734364 |doi= |url=}}</ref>
Once the bowel has rotated into its final position, fixation to the posterior abdomen occurs. The proximal portion of the bowel is fixed to the retroperitoneum early in gestation (at the ligament of Treitz), whereas fixation of the colon is gradual and usually completed near term [15].
**The [[cecum]] becomes mobile when failure of the [[ascending colon]] [[mesentery]] to fuse with the posterior parietal [[peritoneum]] occurs.
 
**Autopsy studies have shown that  about 10-25% of the population have a mobile [[cecum]] and [[ascending colon]] sufficient to develop a volvulus.  
●Normal gut development – Normal rotation and fixation result in a wide-based mesentery that extends from the ligament of Treitz in the left upper quadrant to the ileocecal valve in the right lower quadrant (figure 3). Most anomalies of rotation result in an abnormally narrow mesenteric base (figure 4). Because the midgut is suspended on this narrow vascular pedicle rather than on the wide base of the mesentery, there is a risk of volvulus (torsion of the intestines).
**A congenital mobile [[cecum]] can also cause mobile cecum syndrome.
 
*There are three types of cecal volvulus, type I and II are the most common, type III accounts for the remaining 20% of cases:
●Abnormal gut development – The most common abnormalities of rotation are nonrotation or malrotation (incomplete rotation) abnormalities:
**Type I - organoaxial: 
 
***The [[cecum]] twists in a clockwise manner along its axis.
•If both limbs of the primary loop return to the abdomen with no further rotation, nonrotation occurs. In this condition, the small bowel is located on the right of the abdomen and the colon on the left (image 1). Nonrotation is not as dangerous for the patient as malrotation because, in general, the base of the mesentery is wider than in malrotation, and the risk of volvulus is less. However, nonrotation can be a difficult diagnosis radiologically; symptomatic patients may warrant laparoscopic or open exploration to confirm the diagnosis [8,16]. Asymptomatic patients with radiologic findings suggesting nonrotation can be observed.
***The [[cecum]] fills with air and remains in right lower quadrant.
 
**Type II - organoaxial:
•In malrotation, the duodenojejunal limb remains in a position of nonrotation, and the cecocolic limb has partial rotation (usually approximately 90 degrees instead of 180 degrees). The end result is that the cecum ends up in the mid-upper abdomen and the abnormally positioned cecum is fixated to the right lateral abdominal wall by bands of peritoneum. These bands of peritoneum, called Ladd bands, cross the duodenum and can cause extrinsic compression and obstruction of the duodenum (picture 1).
***The [[cecum]] and a proximal part of the [[ileum]] twist in a counterclockwise direction.
 
***The [[cecum]] becomes inverted and is relocated to the left lower quadrant.
Other rare anomalies of rotation can occur [1]. These include:
**Type III - mesentericoaxial:
***The [[cecum]] folds upwards and back on itself rather than rotating along its axis.


•Reverse rotation of the duodenojejunal limb resulting in a duodenum that rests anterior to the superior mesenteric artery.
==Genetics==
Several genetic and chromosomal mutations have been implicated in causing [[intestinal malrotation]] and other gastrointestinal abnormalities that may later be complicated by volvulus.
===Genetic mutations===
*The forkhead box transcription factor Foxf1 plays a role in normal division and attachments of organs in the gastrointestinal tract.
**Then Foxf1 is knocked out in mice, it was found that [[somatic]] and [[splanchnic]] layers remain fused or incompletely separated.
**Ultimately, this leads to an inability of the [[dorsal mesentery]] to tilt to the left.
*Pitx2 and Isl1 mutations lead to asymmetry of the gastrointestinal organs, attachments and rotations.
*Mutations in beta2 and beta4 subunits of the neuronal [[Nicotinic acetylcholine receptor|nicotinic]] [[acetylcholine]] receptor have been associated with a MMIH syndrome ([[Megacystis (fetal)|megacystis]], microcolon and intestinal hypoperistalsis)
===Chromosomal mutations===
*Deletions at chromosome 16q24.1 are associated with a number of GI tract abnormalities including malrotation and other abnormalities that result in:
**Reduced life expectancy
**Restricted growth
**Dysmorphic facial features
**Learning disability, if the child survives.
*Deletions of the long arm of chromosome 13 are associated with [[Hirschsprung's disease|Hirschsprung disease]] and other GI tract malformations: malrotation, jejunal and ileal [[atresia]], [[agenesis]] of mesentery and [[Hypoplasia|hypoplastic]] gallbladder.
*[[Heterozygous]] mutations in EDNRB (endothelin receptor type B) gene, which is found within the deleted interval, results in [[Hirschsprung's disease|Hirschsprung disease]], but other GI tract malformations have not been reported in conjunction with EDNRB mutations.


•Reverse rotation of the cecocolic limb resulting in a transverse colon that is posterior to the superior mesenteric artery.
== Gross pathology ==
On gross pathology, a distended, air-filled bowel twisted around its [[mesentery]] with or without [[ischemia]], [[necrosis]] and/or [[gangrene]] are characteristic findings of volvulus.


•Reverse rotation of the duodenojejunal limb with normal rotation of the cecocolic limb resulting in a paraduodenal hernia. In this anomaly, the duodenum is located anterior to the superior mesenteric artery. Anterior to the duodenum, the cecocolic limb rotates normally, and the mesentery of the right colon creates a pouch into which the small bowel can herniate.
[[Image:vv.jpg|thumb|center|500px|Red arrow indicates a distended and air-filled segment of bowel. By آرمین - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=30092149]]


== Microscopic pathology ==
On microscopic histopathological analysis, [[Thrombus|thrombi]], [[inflammatory cells]], and [[Necrosis|necrotic]] changes are characteristic findings of volvulus.
==References==
==References==
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{{reflist|2}}
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[[Category:Gastroenterology]]
[[Category:Gastroenterology]]
[[Category:Emergency medicine]]
[[Category:Emergency medicine]]
[[Category:Needs content]]


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Latest revision as of 14:29, 9 January 2018

Rotation of the midgut
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Hadeel Maksoud M.D.[2]


Overview

Regardless of cause, volvulus causes symptoms by two mechanisms: One is bowel obstruction, manifested as abdominal distension and vomiting. The other is ischemia (loss of blood flow) to the affected portion of intestine. This causes severe pain and progressive injury to the intestinal wall, with accumulation of gas and fluid in the portion of the bowel obstructed. Ultimately, this can result in necrosis of the affected intestinal wall, acidosis, and death. Acute volvulus therefore requires immediate surgical intervention to untwist the affected segment of bowel and possibly resect any unsalvageable portion.

Pathophysiology

  • In western society, chronic constipation can lead to an overloaded sigmoid colon.
  • In developing nations, a high fiber diet leads to sigmoidal overload.
  • When the bowel loop is overloaded with material, it becomes susceptible to torsion along the axis of an elongated mesentery.
  • A large pelvic mass or a large gravid uterus can alter the position of the intra-abdominal organs, predisposing to the formation of volvulus.
  • With recurrent attacks of torsion, the base of the mesentery can become chronically inflammed and eventually shortens.
  • This leads to recurrent volvulus.
  • The twisting of a mobile loop of bowel can happen spontaneously and may be congenital or acquired.
  • Acquired causes of volvulus include:[1][2][3]
  • Congenital causes are discussed below.

Intestinal Malrotation in Neonates and Infants

Embryology

  • Malrotation occurs when there is arrest of the normal rotation of the embryonic gut.[4][5]
  • During weeks 4-8 of development, the embryonic coelom, or cavity, normally cannot accommodate the rapidly expanding gastrointestinal (GI) tract.
  • Consequently, the primary intestinal loop pushes back into the yolk stalk, and will become the future umbilicus.
  • The direction in which the loop grows takes the axis of the future superior mesenteric artery.
  • As the primary intestinal loop grows out of the abdomen, it begins to rotate by twisting 90 degrees counterclockwise.
  • There are two factors that force this rotation:
    • The proximal bowel (gastroduodenal) grows faster than the distal bowel (cecocolic).
    • The liver has rapidly develops.
  • During weeks 8 - 10, the primary intestinal loop continues to grow and returns back into the abdomen cavity and a further 180 degree counterclockwise rotation occurs.
  • Overall, the primary loop twists a total of 270 degrees in a counterclockwise direction.
  • Once the primary loop is in its final position, fixation to the posterior abdominal wall begins.
  • The proximal bowel portion including the stomach and duodenum are fixated early in gestation through the ligament of Treitz.
  • The colon takes a longer time to become fixated and usually, fixation is completed near term.

Pathophysiology of Infantile and Neonatal Volvulus

  • Normal gut development means that:[6]
    • A wide-based mesentery will extend from the ligament of Treitz in the left upper quadrant to the ileocecal valve in the right lower quadrant.
    • The primary loop will continue its rotation upon return to the abdominal cavity.
    • Both proximal (duodenojejunal) and distal (cecocolic) limbs rotate at the same rate and to the same degree.
  • Congenital volvulus happens when the following anomalies have occurred:
    • Narrow mesenteric base:
      • The midgut becomes suspended by a narrow pedicle.
    • Non-rotation:
      • In non-rotation, the primary loop undergoes no further rotation during its return to the abdominal cavity.
      • The small bowel becomes located on the right whilst the colon is on the left of the abdomen.
      • Non-rotation is less dangerous than malrotation because in non-rotation, the mesentery is wider and the risk of volvulus is lower.
    • Malrotation:
      • In malrotation, the proximal (duodenojejunal) limb remains in a position of non-rotation, and the distal (cecocolic) limb partially rotates (usually only 90 degrees instead of 180 degrees).
      • Consequently,the cecum is relocated to the mid-upper abdomen, instead of the right lower quadrant.
      • The abnormally-positioned cecum is attached by bands of peritoneum (Ladd bands) to the right lateral abdominal wall.
      • Ladd bands can cause compression and obstruction of the duodenum extrinsically.
  • Other anomalies of rotation can rarely occur, these include:

Ileal and Sigmoid Volvulus

  • The mesentery anchors the ileum and sigmoid colon to the posterior abdominal wall.[7][8]
  • An air filled loop of the sigmoid colon or the terminal ileum, sometimes, twists itself about the axis of the mesentery.
  • The incidence of volvulus occurring increases with a redundant or longer than normal mesentery.
  • If the degree of twisting is beyond 180 - 360 degress, then the bowel loop will become obstructed and ischemia will develop.
  • Ileosigmoid knotting is a variant of sigmoid volvulus where the ileum wraps around the sigmoid in a clockwise direction.

Gastric Volvulus

  • Normally, there are ligaments such as the gastrocolic, gastrohepatic, gastrosplenic and gastrophrenic ligaments that keeps the stomach in place by attaching it to other abdominal organs and the diaphragm.[9][10]
  • However, the stomach can twist around its horizontal or vertical axis.
  • Gastric outlet obstruction may occur as a result of abnormal rotation more than 180 degrees.
  • Chronic rotation can cause bleeding by decreasing venous return and increasing capillary pressure.

Cecal Volvulus

  • The cecum is especially liable to being mobile congenitally.[11][12][13]
    • The cecum becomes mobile when failure of the ascending colon mesentery to fuse with the posterior parietal peritoneum occurs.
    • Autopsy studies have shown that about 10-25% of the population have a mobile cecum and ascending colon sufficient to develop a volvulus.
    • A congenital mobile cecum can also cause mobile cecum syndrome.
  • There are three types of cecal volvulus, type I and II are the most common, type III accounts for the remaining 20% of cases:
    • Type I - organoaxial:
      • The cecum twists in a clockwise manner along its axis.
      • The cecum fills with air and remains in right lower quadrant.
    • Type II - organoaxial:
      • The cecum and a proximal part of the ileum twist in a counterclockwise direction.
      • The cecum becomes inverted and is relocated to the left lower quadrant.
    • Type III - mesentericoaxial:
      • The cecum folds upwards and back on itself rather than rotating along its axis.

Genetics

Several genetic and chromosomal mutations have been implicated in causing intestinal malrotation and other gastrointestinal abnormalities that may later be complicated by volvulus.

Genetic mutations

  • The forkhead box transcription factor Foxf1 plays a role in normal division and attachments of organs in the gastrointestinal tract.
    • Then Foxf1 is knocked out in mice, it was found that somatic and splanchnic layers remain fused or incompletely separated.
    • Ultimately, this leads to an inability of the dorsal mesentery to tilt to the left.
  • Pitx2 and Isl1 mutations lead to asymmetry of the gastrointestinal organs, attachments and rotations.
  • Mutations in beta2 and beta4 subunits of the neuronal nicotinic acetylcholine receptor have been associated with a MMIH syndrome (megacystis, microcolon and intestinal hypoperistalsis)

Chromosomal mutations

  • Deletions at chromosome 16q24.1 are associated with a number of GI tract abnormalities including malrotation and other abnormalities that result in:
    • Reduced life expectancy
    • Restricted growth
    • Dysmorphic facial features
    • Learning disability, if the child survives.
  • Deletions of the long arm of chromosome 13 are associated with Hirschsprung disease and other GI tract malformations: malrotation, jejunal and ileal atresia, agenesis of mesentery and hypoplastic gallbladder.
  • Heterozygous mutations in EDNRB (endothelin receptor type B) gene, which is found within the deleted interval, results in Hirschsprung disease, but other GI tract malformations have not been reported in conjunction with EDNRB mutations.

Gross pathology

On gross pathology, a distended, air-filled bowel twisted around its mesentery with or without ischemia, necrosis and/or gangrene are characteristic findings of volvulus.

Red arrow indicates a distended and air-filled segment of bowel. By آرمین - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=30092149

Microscopic pathology

On microscopic histopathological analysis, thrombi, inflammatory cells, and necrotic changes are characteristic findings of volvulus.

References

  1. ↑ John H, Gyr T, Giudici G, Martinoli S, Marx A (1996). "Cecal volvulus in pregnancy. Case report and review of literature". Arch. Gynecol. Obstet. 258 (3): 161–4. PMID 8781706.
  2. ↑ Radin DR, Halls JM (1986). "Cecal volvulus: a complication of colonoscopy". Gastrointest Radiol. 11 (1): 110–1. doi:10.1007/BF02035046. PMID 3943670.
  3. ↑ Sarioğlu A, Tanyel FC, Büyükpamukçu N, Hiçsönmez A (1997). "Colonic volvulus: a rare presentation of Hirschsprung's disease". J. Pediatr. Surg. 32 (1): 117–8. PMID 9021588.
  4. ↑ Graziano K, Islam S, Dasgupta R, Lopez ME, Austin M, Chen LE, Goldin A, Downard CD, Renaud E, Abdullah F (2015). "Asymptomatic malrotation: Diagnosis and surgical management: An American Pediatric Surgical Association outcomes and evidence based practice committee systematic review". J. Pediatr. Surg. 50 (10): 1783–90. doi:10.1016/j.jpedsurg.2015.06.019. PMID 26205079.
  5. ↑ Diaz MC, Reichard K, Taylor AA (2009). "Intestinal nonrotation in an adolescent". Pediatr Emerg Care. 25 (4): 249–51. doi:10.1097/PEC.0b013e31819e36aa. PMID 19369837.
  6. ↑ Burns, Cartland (2006). "Principles and Practices of Pediatric Surgery". Annals of Surgery. 243 (4): 567. doi:10.1097/01.sla.0000208423.52007.38. ISSN 0003-4932.
  7. ↑ Shepherd JJ (1969). "The epidemiology and clinical presentation of sigmoid volvulus". Br J Surg. 56 (5): 353–9. PMID 5781046.
  8. ↑ VerSteeg KR, Whitehead WA (1980). "Ileosigmoid knot". Arch Surg. 115 (6): 761–3. PMID 7387365.
  9. ↑ Rashid F, Thangarajah T, Mulvey D, Larvin M, Iftikhar SY (2010). "A review article on gastric volvulus: a challenge to diagnosis and management". Int J Surg. 8 (1): 18–24. doi:10.1016/j.ijsu.2009.11.002. PMID 19900595.
  10. ↑ Shivanand G, Seema S, Srivastava DN, Pande GK, Sahni P, Prasad R, Ramachandra N (2003). "Gastric volvulus: acute and chronic presentation". Clin Imaging. 27 (4): 265–8. PMID 12823923.
  11. ↑ Husain K, Fitzgerald P, Lau G (1994). "Cecal volvulus in the Cornelia de Lange syndrome". J. Pediatr. Surg. 29 (9): 1245–7. PMID 7807358.
  12. ↑ DONHAUSER JL, ATWELL S (1949). "Volvulus of the cecum with a review of 100 cases in the literature and a report of six new cases". Arch Surg. 58 (2): 129–48. PMID 18111729.
  13. ↑ Rogers RL, Harford FJ (1984). "Mobile cecum syndrome". Dis. Colon Rectum. 27 (6): 399–402. PMID 6734364.

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