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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.
*The twisting of a mobile loop of bowel can happen spontaneously and may be congenital or acquired.
*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>
**Adhesions
**Iatrogenic e.g. lower GI endoscopy
**Bowel atony
**Hirschsprung's disease
**Pregnancy
*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.
*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 grows faster than the distal bowel.
**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:
**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 whilst returning to the abdominal cavity.
**Both proximal (duodenojejunal) and distal (cecocolic) limbs rotate at the same rate and to the same degree.
*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:
**Rotation of the proximal (duodenojejunal) limb is reversed resulting in a duodenum that is located anteriorly to the superior mesenteric artery.
**Rotation of the distal (cecocolic) limb is reversed resulting in a transverse colon that is located posteriorly 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 creates a pouch, the small bowel then herniates into it.


===Ileal and Sigmoid Volvulus===
===Ileal and Sigmoid Volvulus===
Line 30: Line 80:


===Cecal Volvulus===
===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:
*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>
 
**The cecum becomes mobile when failure of the ascending colon mesentery to fuse with the posterior parietal peritoneum occurs.
*Type I  
**Autopsy studies have shown that  about 10-25% of the population have a mobile cecum and ascending colon sufficient to develop a volvulus.
**The cecum twists in a clockwise manner along its axis.
**A congenital mobile cecum can also cause mobile cecum syndrome.
**The cecum fills with air and remains in right lower quadrant.
*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 II
**Type I  
**The cecum and a proximal part of the ileum twist in a counterclockwise direction.
***The cecum twists in a clockwise manner along its axis.
**The cecum becomes inverted and is relocated to the left lower quadrant.
***The cecum fills with air and remains in right lower quadrant.
*Type III
**Type II
**The cecum folds upwards and back on itself rather than rotating along its axis.
***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].
 
 
===Intestinal Malrotation in Neonates and Infants ===
 
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".)
 
●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]:
 
•The proximal bowel (the "prearterial" or duodenojejunal loop) grows faster than the distal bowel (the "postarterial" or cecocolic loop), and
 
•The rapid growth of the liver.
 
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).
 
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].
 
●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).
 
●Abnormal gut development – The most common abnormalities of rotation are nonrotation or malrotation (incomplete rotation) abnormalities:
 
•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.
 
•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).
 
Other rare anomalies of rotation can occur [1]. These include:
 
•Reverse rotation of the duodenojejunal limb resulting in a duodenum that rests anterior to the superior mesenteric artery.
 
•Reverse rotation of the cecocolic limb resulting in a transverse colon that is posterior to the superior mesenteric artery.


•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.


==References==
==References==

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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

  • 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]
    • Adhesions
    • Iatrogenic e.g. lower GI endoscopy
    • Bowel atony
    • Hirschsprung's disease
    • Pregnancy
  • 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.
  • 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 grows faster than the distal bowel.
    • 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:
    • 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 whilst returning to the abdominal cavity.
    • Both proximal (duodenojejunal) and distal (cecocolic) limbs rotate at the same rate and to the same degree.
  • 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:
    • Rotation of the proximal (duodenojejunal) limb is reversed resulting in a duodenum that is located anteriorly to the superior mesenteric artery.
    • Rotation of the distal (cecocolic) limb is reversed resulting in a transverse colon that is located posteriorly 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 creates a pouch, the small bowel then herniates into it.

Ileal and Sigmoid Volvulus

  • The mesentery anchors the ileum and sigmoid colon to the abdominal wall.[4][5]
  • 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.[6][7]
  • 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.[8][9][10]
    • 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 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.


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. ↑ Shepherd JJ (1969). "The epidemiology and clinical presentation of sigmoid volvulus". Br J Surg. 56 (5): 353–9. PMID 5781046.
  5. ↑ VerSteeg KR, Whitehead WA (1980). "Ileosigmoid knot". Arch Surg. 115 (6): 761–3. PMID 7387365.
  6. ↑ 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.
  7. ↑ 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.
  8. ↑ Husain K, Fitzgerald P, Lau G (1994). "Cecal volvulus in the Cornelia de Lange syndrome". J. Pediatr. Surg. 29 (9): 1245–7. PMID 7807358.
  9. ↑ 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.
  10. ↑ Rogers RL, Harford FJ (1984). "Mobile cecum syndrome". Dis. Colon Rectum. 27 (6): 399–402. PMID 6734364.

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