eMedicine Specialties > Pediatrics: General Medicine > Gastroenterology

Intestinal Volvulus

Author: Andre Hebra, MD, Chief, Division of Pediatric Surgery, Medical University of South Carolina; Professor of Surgery and Pediatrics, Medical University of South Carolina
Coauthor(s): Melissa Miller, MD, Department of Surgery, Medical University of South Carolina
Contributor Information and Disclosures

Updated: Sep 11, 2008

Introduction

Background

The study and treatment of malrotation and volvulus have a long and intriguing history. In 1832, Reid described a malpositioned cecum, found in the left upper quadrant, in 2 autopsies.¹ However, the landmark work of Mall in 1898 first contributed to the understanding of normal embryological GI rotation and development, resulting from his study of 41 cadavers.²

Over the next 35 years, studies continued on intestinal rotation, and case reports of malrotation began appearing in medical literature, along with attempts at treatment and correction. In 1932, Ladd published his landmark paper on congenital duodenal obstruction and presented a surgical correction of malrotation.³ This technique has survived the past century with only minor modifications to form the basis of surgical treatment today. The understanding of GI embryology heavily contributed to the development of a successful treatment and has remained vital to the ability to recognize clinical presentations and implications of this abnormality.

Pathophysiology

A good comprehension of the embryological development of the GI tract is central to the understanding of malrotation and volvulus. At 4 weeks' gestation, the GI system is a straight tube centrally located in the abdomen. During the fifth week, the first stage of rotation begins and lasts until the tenth week. The tube lengthens and herniates into the umbilical cord carrying its blood supply, the superior mesenteric artery (SMA), with it as an axis; it is in line with the omphalomesenteric duct, which is located at the apex of the herniation.

The prearterial segment includes the developing duodenum, jejunum, and much of the ileum, while the postarterial segment becomes the terminal ileum, cecum, ascending colon, and part of the transverse colon. While in this position, the developing midgut begins to rotate. The duodenojejunal (DJ) loop is first pushed inferiorly and to the right, possibly by the developing liver. Rotation is in a counterclockwise direction and continues in this fashion. This completes the first 90° of rotation. The cecocolic loop follows, moving to the left of the artery. The DJ loop then completes a second 90° of rotation, coming to rest inferior to the SMA.

The second stage of rotation occurs at 10-12 weeks' gestation and involves the return of the intestine to the abdominal cavity. Upon return of the prearterial segment, the DJ loop completes another 90° of rotation for a total of 270°, coming to rest to the left of the SMA. The cecocolic loop also completes another 90° of rotation, coming to rest superior and anterior to the SMA.

The third and final phase of rotation occurs after 12 weeks' gestation. The cecum completes its final descent to the right lower quadrant, accomplishing another 90° of rotation or 270° total. Once this is completed, the intestine becomes fixed to the posterior abdominal wall. The DJ junction is fixed to the left of the aorta, anterior to the left renal vein at the ligament of Treitz, and the cecum forms attachments to the right iliac fossa. These 2 points of attachment leave the mesentery and its blood supply broad-based and fixed. Arrest of development at any stage not only changes anatomical placement of organs but, perhaps most importantly, narrows the mesenteric base and impairs fixation, leaving the bowel at high risk for volvulus.

The common rotational abnormalities can be divided into stage of occurrence. Arrest of the first phase leaves the bowel herniated into the umbilical cord, creating omphalocele. This is often accompanied by other congenital abnormalities. Developmental arrest during the second phase may result in nonrotation, incomplete rotation, hyperrotation, or reversed rotation. In addition, gastroschisis and diaphragmatic hernias occur during this period. Mesocolic paraduodenal hernias also occur during the late second phase and early third phase. Failure of the third phase results in a mobile cecum, unattached duodenum, or unattached small bowel mesentery, which allows cecal volvulus and internal hernias.

Nonrotation is the most common abnormality and results from failure of normal counterclockwise rotation around the SMA. Rotation may be completely absent or arrested at 90°. The small intestine remains entirely to the right of the artery, with the cecum at or near the midline and the colon in the left abdomen. The proximal jejunum and colon pass very closely to the SMA, leaving a narrow pedicle as the base of the mesentery. This is sometimes called the "bell-clapper" or the omega configuration and leaves the midgut highly susceptible to volvulus and infarction. Also, the peritoneal attachments of the cecum pass anterior and lateral to the duodenum, leading to future extrinsic partial obstruction.

Incomplete rotation is the next most common abnormality and involves arrest of rotation at or near 180°. This arrest leaves the cecum in the upper abdomen and the DJ junction short of its left abdomen destination. In this case, the SMA pedicle is also narrow and susceptible to volvulus. Cecal peritoneal bands once again cross over the duodenum to the right upper quadrant. These abnormal cecal attachments are called Ladd bands. In both nonrotation and incomplete rotation, cecal bands may cause obstruction and ischemia before birth, leading to congenital duodenal atresia or stenosis. Therefore, patency of the duodenum should be checked routinely during corrective surgery. In addition, intermittent antenatal volvulus may cause varying degrees of ischemia, leading to atresia or duplication of parts of the jejunum and ileum.

Mixed rotational abnormalities are more uncommon and varied. Hyperrotation may narrow the SMA pedicle or lead to a confusing clinical picture in appendicitis. Failure of descent of the cecum may be inconsequential or lead to cecal volvulus. Reversed rotation results in a 90° clockwise rotation, leaving the transverse colon behind the SMA and the duodenum anterior to the artery. In this case, the transverse colon may herniate into a mesocolic pocket or become obstructed by the SMA.

Mesocolic paraduodenal hernias occur with failure of fixation to the posterior abdominal wall. Spaces remain between the mesentery and the wall, allowing possible sequestration and strangulation of bowel segments. This occurs more often on the left and is associated with nonrotation. Right-sided hernia is associated with congenital short bowel.

Volvulus of the midgut may result in several manifestations. Venous and lymphatic obstructions occur first because of lower intravascular pressures. Vascular congestion leads to bowel edema and possible oozing of blood, causing melena. Lymphatic congestion causes the formation of a mesenteric cyst and chylous ascites. If volvulus is intermittent, children may have chronic malabsorption from congestion and edema or intermittent bouts of symptoms, usually vomiting and alternating diarrhea and constipation. Arterial compromise requires higher obstructive pressures but is more acutely dangerous. Sequelae include ischemia, mucosal necrosis, intramural air formation, gram-negative sepsis, perforation, peritonitis, and death.

Malrotation is often associated with other congenital abnormalities, and, in some hospitals, as many as 62% of cases are associated with these abnormalities. This is important for several reasons. First, some abnormalities are highly associated with malrotation, such as polysplenia, asplenia, and congenital abdominal wall defects. The presence of these abnormalities should automatically lead to investigation for malrotation. Patients with congenital wall defects by nature have some aspect of malrotation, which should be examined and fixed during correction of the defect. Rotational anomalies in conjunction with dextro-isomerism or levo-isomerism should point to polysplenia or asplenia syndrome. These syndromes have devastating effects on outcomes, especially asplenia.

Perhaps most importantly, mortality related to malrotation and its correction highly correlates with the presence or absence of other congenital abnormalities. Serious anomalies may raise the risk of mortality 22 times. The pediatrician and surgeon must be conscientious in exploring the possibilities of associated congenital abnormalities.

Frequency

United States

Malrotation is estimated to occur in 1 per 500 live births. Autopsy studies have shown incidence of malrotation in 0.2-1% in the total population; however, clinical discovery is achieved in only 1 per 600 live births. Increasingly, many cases are diagnosed at laparotomy for other congenital abnormalities as physician awareness of associated anomalies improves. A mobile cecum or a high cecum (found in the right upper quadrant) may be considered a minor rotational abnormality but is considered a normal finding in the absence of symptoms and has been recorded in 6-16% of the total population. Its incidence is slightly higher in the immature infant abdomen and may confuse the diagnosis of true malrotation.

International

Incidence internationally is similar to incidence in the United States.

Mortality/Morbidity

Morbidity and mortality of malrotation and volvulus has significantly decreased since the advent of surgical correction. Early figures on the mortality rate ranged from 23-33%, mostly resulting from bowel dysfunction and malnutrition. With the development of total parenteral nutrition and improved nutritional support, survival has increased. In addition, improved knowledge of pathophysiology and the correlation of associated anomalies have allowed for more rapid diagnosis. Clinical awareness of the association of malrotation with other anomalies and increased sensitivity to the importance of more minor symptoms has led to improved diagnosis, allowing for correction of malrotation before life-threatening volvulus occurs. The significance of rapid diagnosis is evident in the high mortality rate (£ 33%) still shown with diagnostic delay, especially in very young persons. Present mortality figures range from around 3-9% overall.

• In 1992, Messineo et al determined that the most important factors influencing mortality are the presence of necrotic bowel, associated abnormalities, and younger age.⁴ Risk of mortality increases 25 times in the presence of bowel necrosis and is influenced heavily by length of viable bowel. They determined that the survival rate is maintained above 93% with 10%, 25%, and 50% of the bowel necrosed; however, the survival rate drops to 35% with the loss of 75% of the length of the small bowel. The presence of other serious abnormalities also increases the risk of mortality by a factor of 22. Given the high association of malrotation with other congenital anomalies, this risk factor heavily affects mortality figures. In addition, Messineo et al found that patients who died after surgery had a significantly lower median age (4 d versus 30 d).
• The most common cause of death in these patients is sepsis. Other noted causes are pneumonia, intracranial hemorrhage, short-bowel syndrome, malnutrition, renal failure or hepatic failure, continued small bowel obstruction, and other life-threatening anomalies.
• Causes of postoperative morbidity are adhesive obstruction, short-bowel syndrome, and recurrent volvulus. Adhesive obstruction has been noted in 1-10% of these patients postoperatively and can contribute to renewed symptoms of partial to complete obstruction. Short-bowel syndrome may occur after resection of a significant length of necrotic bowel. Children with malrotation and volvulus comprise 18% of the population of patients with short-bowel syndrome, which can result in chronic learning and psychomotor disabilities as well as the obvious risk of malnutrition. Midgut volvulus recurs after the Ladd procedure in 7% of cases. This has resulted in several attempts over the past century to augment the Ladd procedure with fixation of the cecum and duodenum; however, overall statistics have not shown improvement in outcome. Therefore, patient education on the signs and symptoms of obstruction and volvulus has proved the only effective prevention of the consequences of recurrent volvulus.
• In general, in the absence of other significant abnormalities or bowel necrosis secondary to midgut volvulus, morbidity and mortality of malrotation and its correction are low, and these children can be expected to do well, with an excellent chance of total resolution of related symptoms. Volvulus has been reported in 45-80% of infants with malrotation and is much more life threatening. Surgical correction is highly recommended as long as other systems are stable enough to undergo the procedure. In addition, malrotation places the infant at increased risk for intussusception. Waugh syndrome, the presence of intussusception and malrotation, was first described in 1911. Poor fixation of the cecum allowing easier ileal advancement is noted in almost all infants with intussusception and is central to the pathophysiology of malrotation.
• Patients who are asymptomatic and whose condition is undiagnosed before age 2 years may never become symptomatic; however, without operation, malrotation results in volvulus in 1 out of 3 throughout a lifetime.

Race

No known racial difference has been reported.

Sex

During the first week of life, the ratio of male-to-female presentation is 2:1. In the 25% of patients diagnosed with this condition after age 1 year, the male-to-female ratio equalizes, creating an overall ratio of 3 males to 2 females. Reasons for the slight male predominance are largely unknown.

Age

The presentation of symptomatic malrotation is much more common in younger children. Children younger than 1 year account for 75-90% of cases, with 50-64% of cases occurring in infants younger than 1 month and 25-40% of cases occurring in the first week of life.

Clinical

History

No unique signs or symptoms pathognomonic for intestinal malrotation and volvulus are recognized; however, the most common presenting symptom is bilious vomiting (ie, vomiting yellow or green). Physicians must recognize that bilious vomiting can occur in various other medical conditions, but, given the significant morbidity and mortality of midgut volvulus, any patient with bilious vomiting must be considered at risk for having a midgut volvulus until proven otherwise. See Media files 5-6.

• Malrotation
  • The typical history of a patient with intestinal malrotation depends on age at presentation and degree of obstruction.
  • Infants who present in the first 24 hours after birth through the first week of life tend to have more severe obstruction. They present with bilious vomiting and feeding intolerance, as expected of a high postampullary obstruction. They may also have upper abdominal distension.
  • Slightly older infants often also present with bilious vomiting and have a history of tolerating at least some feeds. After age 2 months, bilious and nonbilious vomiting occurs with similar frequency.
  • Other symptoms include anorexia, intermittent apnea, and failure to thrive. Parents may report constipation, which results from obstruction as well as dehydration due to decreased fluid intake. Bloody stools may signify volvulus.
• Malrotation in older children
  • Older children present more insidiously. Symptoms include cyclic vomiting, immunodeficiency, and protein-calorie malnutrition.
  • Malrotation may cause secondary illness such as peptic ulcer disease due to gastroduodenal stasis or intussusception caused by lack of ileal fixation.
  • Altered anatomy may also cause a delay in the diagnosis of appendicitis.
  • In general, younger children are more likely to present with acute symptoms lasting less than 48 hours.
  • An abrupt change from feed tolerance to vomiting and irritability at any age is suspicious for volvulus in the presence of known malrotation.
• Volvulus
  • Malrotation and volvulus are 2 distinct entities. Malrotation may cause intermittent and incomplete signs and symptoms of proximal intestinal obstruction with mesenteric congestion. If volvulus has developed as a consequence of intestinal malrotation, the obstruction is typically complete, and compromise to the blood supply of the midgut has started (because of the twisting of the mesentery at the narrow pedicle of the superior mesenteric artery). Media files 5-6 illustrate the operative appearance of a midgut volvulus. Thus, the signs and symptoms depend on the degree of ischemia. It can range from lymphatic and venous congestion with simple edema to full intestinal necrosis secondary to arterial and venous thrombosis. See Media file 8.
  • Once intestinal ischemia develops, pain becomes a more pronounced symptom, and the patient may have signs of an acute abdomen with rigidity and tenderness to palpation.
  • Because superior mesenteric artery (SMA) territory includes the segment from the proximal duodenum to the mid transverse colon, the entire midgut may become necrotic and nonviable if the volvulus is not corrected in time. Necrosis of the entire midgut is incompatible with life.

Physical

• Physical findings in malrotation are predictable because of the anatomy.
  • Abdominal distension may be present in the epigastric area, especially in infants younger than 1 year. Distension may be absent even in this age group if vomiting has cleared gastric contents.
  • Peristaltic waves may also be visible in the epigastrium moving obliquely down from right to left.
  • Bilious or nonbilious emesis may be present.
  • Infants may also show evidence of dehydration and weight loss.
  • Signs of shock combined with bloody diarrhea and abdominal distension usually signify volvulus and possible gangrene. Such patients need urgent laparotomy as soon as possible.
• Physical examination findings in older children may be more subtle and nonspecific.
  • Evidence of weight loss and malnutrition may be present, and stools may contain occult blood in the case of intermittent volvulus.
  • A secondary disease process, such as peptic ulcer disease, may be the only presenting sign.
  • Inconclusive findings on examination of an older child with a chronic history of vomiting and nonspecific symptoms warrant radiologic studies to rule out malrotation or other obstruction.
• Physical findings associated with volvulus are as follows:
  • As previously mentioned, in the event of malrotation with midgut volvulus, vascular compromise develops and this determines the severity of the clinical presentation.
  • The physical signs may vary from mild abdominal pain to severe pain with an acute abdomen or even a shocklike picture with dehydration, lethargy, and respiratory distress.

Causes

Specific causes of malrotation are unknown, although repeated associations have been made with congenital syndromes such as Down syndrome and VACTERL (vertebral, anal, cardiac, tracheal, esophageal, renal, limb) association of anomalies. Because malrotation is an embryological development abnormality, the assumption can be made that any interference during critical periods may lead to malrotation.

Associated anomalies include the following:

• Trisomy 21
• Congenital heart disease
• Imperforate anus
• Ileal and jejunal atresia or duplication
• Omphalocele
• Duodenal atresia and stenosis
• Diaphragmatic hernia
• Meckel diverticulum
• VACTERL (vertebral, anal, cardiac, tracheal, esophageal, renal, limb) association of anomalies
• Trisomy 13, trisomy 18
• Esophageal atresia
• Situs inversus and asplenia (may be associated with biliary atresia)
• Kidney abnormalities
• Agenesis of corpus callosum
• Pyloric stenosis
• Annular pancreas
• Erythroblastosis
• Intussusception
• Cystic fibrosis
• Meconium ileus
• Hirschsprung disease
• Duodenal web
• Biliary atresia

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