Description

A volvulus is a complete twisting of a loop of intestine around its mesenteric attachment site. This can occur at various locations of the gastrointestinal (GI) tract, including the stomach, small intestine, caecum, transverse colon, and sigmoid colon. Midgut malrotation refers to twisting of the entire midgut about the axis of the superior mesenteric artery (SMA).¹

A knowledge of embryology is necessary to understand the mechanisms that lead to the development of volvulus and malrotation.² At the fourth week of gestation, the gastrointestinal system is a straight tube centrally located in the abdomen. During the ensuing eight weeks, the midgut rotates and becomes fixed to the posterior abdominal wall. Arrest of development at any stage narrows the mesenteric base and impairs fixation, leaving the bowel at high risk for volvulus.¹

Epidemiology

Nonrotation occurs in approximately 1 in 500 live births.³ However, the true incidence of malrotation is unknown, since many asymptomatic patients fail to present. Either sex can be affected with the anomaly.⁴ In approximately 60% of patients, malrotation presents by age 1 month. Another 20-30% of patients present at age 1-12 months.⁵ Thereafter, it can present at any age, and is seen in adults and even in the elderly.⁶

Presentation

It should be remembered that malrotation and volvulus are two distinct entities. Nonrotation may be asymptomatic and be detected as an incidental finding during GI imaging for some other purpose. Malrotation may cause intermittent symptoms of intestinal obstruction, but if a volvulus develops, the obstruction is typically complete. The presenting features will also vary, depending on age.⁷

Bilious vomiting is the key presenting symptom. A child presenting with green or yellow vomiting should be presumed to have volvulus until proved otherwise. Infants presenting in the first 24 hours after birth through the first week of life tend to have more severe obstruction, and present with bilious vomiting and feeding intolerance. After the age of 2 months, bilious and nonbilious vomiting occur with equal frequency. Other symptoms may include failure to thrive, anorexia, constipation, bloody stools, and intermittent apnoea.^7,8

Older children may present more insidiously with cyclical vomiting, recurrent abdominal pain, protein-calorie malnutrition and immunodeficiency.⁷ Once intestinal ischaemia develops, pain becomes the most pronounced symptom.

Rarely, volvulus can occur in utero and even more rarely can lead to intrauterine death.⁹
Abdominal examination may be normal in the early stages,¹⁰ or may show distension.¹¹

Intestinal malrotation can be a rare cause of chronic abdominal pain in adults. The diagnosis is often missed initially, leading to increased morbidity.¹²

Careful examination may reveal a palpable abdominal mass in some patients.⁷ If ischaemia develops, the presentation is of acute abdomen, with significant abdominal distension, and signs of peritonitis. Blood or sloughed tissue may pass per rectum. Tachycardia, hypovolaemia and septic shock herald the onset of gangrene.¹³

Differential diagnosis^1,5,7

In the acute phase, the differential diagnosis is of acute abdomen/obstruction. Chronic vague abdominal symptoms in older children or adults raise the possibility of a wide range of other symptoms, which should include:

• Annular pancreas
• Appendicitis
• Cholecystitis
• Colic
• Constipation
• Duodenal atresia
• Duodenal web
• Gastroenteritis
• Gastro-oesophageal reflux
• Henoch-Schönlein purpura
• Hepatitis B
• Hirschsprung's disease
• Hypertrophic pyloric stenosis
• Incarcerated hernia
• Intussusception
• Meckel's diverticulum
• Necrotising enterocolitis
• Ovarian torsion
• Pancreatitis
• Peptic ulcer
• Perforated viscus
• Renal stones
• Sickle cell crisis
• Urinary tract infection

Investigations

Laboratory investigations

The diagnosis is usually made clinically, and management should not be delayed in order to obtain the results of laboratory tests.⁷ FBC helps to assess the severity of the illness; a raised white cell count may be found in sepsis or gangrene and a low haemoglobin may suggest venous oozing. Regular U&E monitoring may help to assess the patient's general condition and detect dehydration, sepsis and acidosis. Large amounts of fluid can migrate into the bowel lumen and interstitial space and, in such patients, dehydration can occur without diarrhoea and vomiting. Hyponatraemia, hyperkalaemia, metabolic acidosis, increased urea and creatinine, hypochloraemia and lactic acidosis can occur in such cases.

Plain radiography

In simple malrotation, plain radiographs are frequently normal. Upright, supine and lateral radiographs may be helpful in diagnosing bowel obstruction but may be more contributory in large rather than small bowel obstruction. Radiographs taken several hours apart may be helpful. Dilated small-bowel loops, marked gastric or proximal duodenal dilatation, with or without intestinal gas, and air-fluid levels may be seen. Normal or equivocal results should not delay progress to other tests if the clinical situation is deteriorating.¹⁴

In midgut volvulus, the classic radiographic finding is a partial duodenal obstruction (dilation of both stomach and proximal duodenum, with a small amount of distal bowel gas). This is known as the 'double bubble' sign. Complete obstruction of the duodenum may also be found; less frequently, a gasless abdomen, ileus, or distal small bowel obstruction with multiple dilated loops and air-fluid levels. These are ominous signs.^5,15

Contrast studies

In malrotation, the duodenojejunal (DJ) junction is misplaced, either at, or to the right of, the midline. Various displacements of lower bowel structures may also be seen.⁵

An upper GI (UGI) contrast series is the investigation par excellence if volvulus is suspected. In a child, the UGI series is performed with a small amount of barium being administered either by bottle or through a nasogastric tube. Various patterns may be observed, including dilation of the proximal duodenum with a 'bird-beak' obstruction and a spiral or corkscrew duodenal configuration.¹⁶ Selected patients may need studies of the lower bowel, using a barium enema.

Other imaging studies

Ultrasound may reveal a midline abdominal mass in suspected volvulus. Ultrasound and CT scanning can help to confirm malrotation by identifying the position of the mesenteric vessels.¹⁷ CT scan may reveal 'the coffee bean' in sigmoid volvulus.¹⁸ The 'whirlpool sign' on colour Doppler may show a whirlpool pattern of flow within the superior mesenteric vein, indicating malrotation with volvulus.¹⁹ The low specificity of these tests suggests that, whilst they may be useful screening tools, they are inferior to the UGI contrast series in the acute situation.

Management

Nonsurgical

This may be appropriate for older patients with intestinal malrotation who are asymptomatic but they should be warned that volvulus can occur at any time.²⁰ Observation and GI decompression with a nasogastric or orogastric tube should be commenced and a close watch kept for the development of symptoms or signs suggestive of intestinal obstruction.⁷

Surgery

Ladd's procedure is the treatment of choice in most cases. Volvulus is corrected by rotating the small intestine in an anti-clockwise direction, the caecum being placed in the left abdomen and the duodenum directed down the right paravertebral gutter. A second-look laparotomy may be used 36 hours later to ensure viability of the remaining bowel.

A laparoscopic variation of Ladd's procedure has been used in some centres, with the general advantage of decreased adhesions and scarring, but good visualisation of the entire bowel is necessary.²¹ Laparoscopy is a particularly suitable investigative procedure for children presenting with acute abdomen. One study found that it produces better cosmesis, less postoperative pain and earlier return of bowel function than laparotomy.²²

Complications

• Complete and persisting midgut volvulus leads to intestinal ischaemia, mucosal necrosis and sepsis. Untreated, perforation, peritonitis and death soon follow.⁷
• Chronic intermittent volvulus may cause malabsorption with constipation interspersed with diarrhoea.²³
• Postoperatively, the main complication is short-gut syndrome with the consequent problems surrounding parenteral nutrition, i.e. line sepsis, hepatobiliary dysfunction and growth retardation.²⁴

Prognosis

Midgut volvulus carries a mortality rate of 3-15%.¹ Survival rate is dependent, to some extent, on the amount of ischaemic bowel which has to be excised²⁵ and on the length of delay before the condition is diagnosed and treated.

Prevention

Because volvulus is such a devastating complication in children, evidence supports operative treatment of asymptomatic malrotation, using Ladd's procedure. This is particularly appropriate for young children with no existing comorbidity, as they recover quickly. There is no similar evidence base to support this approach in adults.²⁶

Document references

1. Markowitz JE et al, Volvulus, eMedicine, May 2008
2. Kluth D, Jaeschke-Melli S, Fiege H, The Embryology of Gut Rotation
3. Stewart DR, Colodny AL, Daggett WC; Malrotation of the bowel in infants and children: a 15 year review.; Surgery. 1976 Jun;79(6):716-20. [abstract]
4. Kamal IM; Defusing the intra-abdominal ticking bomb: intestinal malrotation in children.; CMAJ. 2000 May 2;162(9):1315-7.
5. Reid J, Midgut Volvulus Imaging, eMedicine, Mar 2010
6. von Flue M, Herzog U, Ackermann C, et al; Acute and chronic presentation of intestinal nonrotation in adults.; Dis Colon Rectum. 1994 Feb;37(2):192-8. [abstract]
7. Hebra A et al, Intestinal Volvulus, eMedicine, Mar 2010
8. Uba AF, Chirdan LB, Edino ST; Intestinal malrotation: presentation in the older child.; Niger J Med. 2005 Jan-Mar;14(1):23-6. [abstract]
9. Steffensen TS, Gilbert-Barness E, DeStefano KA, et al; Midgut volvulus causing fetal demise in utero. Fetal Pediatr Pathol. 2008 Dec;27(4):223-31. [abstract]
10. Bonadio WA, Clarkson T, Naus J; The clinical features of children with malrotation of the intestine.; Pediatr Emerg Care. 1991 Dec;7(6):348-9. [abstract]
11. Ameh EA, Nmadu PT; Intestinal volvulus: aetiology, morbidity, and mortality in Nigerian children.; Pediatr Surg Int. 2000;16(1-2):50-2. [abstract]
12. Fu T, Tong WD, He YJ, et al; Surgical management of intestinal malrotation in adults. World J Surg. 2007 Sep;31(9):1797-803; discussion 1804-5. [abstract]
13. Atamanalp SS, Yildirgan MI, Basoglu M, et al; Sigmoid colon volvulus in children: review of 19 cases.; Pediatr Surg Int. 2004 Jul;20(7):492-5. Epub 2004 Jul 6. [abstract]
14. Paslawski M, Gwizdak J, Zlomaniec J; The diagnostic value of different imaging modalities in evaluation of bowel obstruction.; Ann Univ Mariae Curie Sklodowska [Med]. 2004;59(2):268-74. [abstract]
15. Oh SK, Han BK, Levin TL, et al; Gastric volvulus in children: the twists and turns of an unusual entity. Pediatr Radiol. 2008 Mar;38(3):297-304. Epub 2008 Jan 16. [abstract]
16. Long FR, Kramer SS, Markowitz RI, et al; Radiographic patterns of intestinal malrotation in children.; Radiographics. 1996 May;16(3):547-56; discussion 556-60. [abstract]
17. Zerin JM, DiPietro MA; Mesenteric vascular anatomy at CT: normal and abnormal appearances.; Radiology. 1991 Jun;179(3):739-42. [abstract]
18. Salati U, McNeill G, Torreggiani WC, et al; The coffee bean sign in sigmoid volvulus. Radiology. 2011 Feb;258(2):651-2.
19. Orzech N, Navarro OM, Langer JC; Is ultrasonography a good screening test for intestinal malrotation?; J Pediatr Surg. 2006 May;41(5):1005-9. [abstract]
20. McVay MR, Kokoska ER, Jackson RJ, et al; Jack Barney Award. The changing spectrum of intestinal malrotation: diagnosis and management. Am J Surg. 2007 Dec;194(6):712-7; discussion 718-9. [abstract]
21. Matzke GM, Dozois EJ, Larson DW, et al; Surgical management of intestinal malrotation in adults: comparative results for open and laparoscopic Ladd procedures.; Surg Endosc. 2005 Oct;19(10):1416-9. Epub 2005 Aug 25. [abstract]
22. Palanivelu C, Rangarajan M, Shetty AR, et al; Intestinal malrotation with midgut volvulus presenting as acute abdomen in children: value of diagnostic and therapeutic laparoscopy. J Laparoendosc Adv Surg Tech A. 2007 Aug;17(4):490-2. [abstract]
23. Imamoglu M, Cay A, Sarihan H, et al; Rare clinical presentation mode of intestinal malrotation after neonatal period: Malabsorption-like symptoms due to chronic midgut volvulus.; Pediatr Int. 2004 Apr;46(2):167-70. [abstract]
24. Thakur A, Chiu C, Quiros-Tejeira RE, et al; Morbidity and mortality of short-bowel syndrome in infants with abdominal wall defects. Am Surg. 2002 Jan;68(1):75-9. [abstract]
25. Messineo A, MacMillan JH, Palder SB, et al; Clinical factors affecting mortality in children with malrotation of the intestine.; J Pediatr Surg. 1992 Oct;27(10):1343-5. [abstract]
26. Malek MM, Burd RS; The optimal management of malrotation diagnosed after infancy: a decision analysis.; Am J Surg. 2006 Jan;191(1):45-51. [abstract]

Internet and further reading

• Mohan P, Ramamoorthy M, Venkataraman J; Clinical vistas: nonrotation of the intestine. CMAJ. 2008 Jul 1;179(1):49-50.

Acknowledgements