OVERVIEW: What every practitioner needs to know

Are you sure your patient has intestinal malrotation with volvulus? What are the typical findings for this disease?

Interruption of normal intestinal rotation and fixation during fetal development results in the congenital abnormality termed “malrotation”. Malrotation and its dreaded complication of midgut volvulus continues to represent a complex and challenging problem for surgeons and all others involved. It applies to a wide spectrum of intestinal abnormalities depending on the developmental stage at which normal embryological rotation fails.

Malrotation can present in a variety of ways, depending on the degree of duodenal obstruction and the presence or absence of midgut volvulus. The classic clinical presentation for malrotation is that of midgut volvulus in an otherwise healthy infant. The presenting symptoms include the acute onset of bilious vomiting and abdominal distension, followed by abdominal wall erythema, rigidity and peritonitis if left untreated. The initial abdominal exam may be completely normal, lulling the practitioner into dismissing the diagnosis, which unfortunately may lead to progressive bowel ischemia, hypovolemic shock and possibly death.

The clinical picture may be less distinct in older children and adults, especially those with atypical malrotation. Their symptoms may range from acute abdominal pain with bilious vomiting to chronic vague abdominal discomfort with nausea, diarrhea and malabsorption. Other less common manifestations include bloating, constipation, GI bleeding, chylous ascites, feeding intolerance and failure to thrive.

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Chronicity and the non-specific nature of related symptoms may result in a delay in diagnosis and treatment, leading to an intra-abdominal catastrophe. Thus, it is imperative that intestinal malrotation be considered and recognized as a possible etiology in all cases of bilious vomiting, as well as those patients who present with chronic abdominal symptoms. Delays between the initial presentation and the diagnosis have been reported up to 5 years. The diagnosis may occasionally be entertained at laparotomy for an unrelated problem or as an incidental finding during routine imaging.

Variants of malrotation

Malrotation has been classified into typical and atypical variants based on the location of the ligament of Treitz (LOT) and its relationship to the gastric outlet and midline:

  • A normal position of LOT is implicit in the location of the duodeno-jejunal junction to the left of the spine, at the level of the duodenal bulb.

  • Classic or typical malrotation is defined anatomically by a LOT that is either non-existent or located to the right of midline. Proximal jejunal loops are located in the right upper quadrant or midline. The cecum is usually unattached, very mobile and therefore absent from its usual right lower quadrant position.

  • Atypical malrotation, also known as malrotation variant, is identified when the LOT is midline or to the left of midline but does not rise to its usual location at or above the level of the duodenal bulb. The cecum may be found in a normal location, be unusually mobile or elevated in the right mid abdomen.

What other disease/condition shares some of these symptoms?

Malrotation is a natural consequence of several congenital anomalies particularly omphalocele, gastroschisis, congenital diaphragmatic hernia and can be found in infants with heterotaxy. It is associated with several syndromes including: Cornelia de Lange syndrome, Cantrell syndrome, Cat eye syndrome, Marfan syndrome, Chromosomal abnormalities (trisomies 13, 18, and 21), Coffin-Siris syndrome, Prune-Belly syndrome and mobile cecum syndrome.

Various anatomic intestinal anomalies have been found to be associated with malrotation including intestinal/biliary stenosis and atresia, duodenal web, anorectal malformation, Meckel’s diverticulum, intussusception, pyloric stenosis, Hirschsprung’s disease and mesenteric cysts. Several associated cardiac and renal anomalies have been described in association with malrotation and should be carefully ruled out.

What caused this disease to develop at this time?

The embryology of malrotation was first described by Mall in 1898, followed later by Dott, who in 1923 described the relationship between anatomy and clinical outcome. The process of intestinal rotation and fixation begins during the 5th gestational week and involves a series of orderly steps beginning with elongation and herniation of the bowel into the umbilical cord. The segments of developing midgut proximal and distal to the superior mesenteric artery (SMA) are termed the pre-arterial or duodeno-jejunal (DJ) limb and post-arterial or ceco-colic (CC) limb; they form a U loop around the SMA axis. Over the next 5 weeks, the bowel undergoes 270 degrees of counter-clockwise rotation around the SMA as it returns to the peritoneal cavity, resulting in fixation of the bowel in its normal anatomic position.

During stage I of rotation (5th-10th week of gestation), the DJ loop begins superior to the SMA and rotates 90 degrees counter-clockwise to a position to the right of the SMA, while the CC loop begins inferior to the SMA and rotates 90 degrees counter-clockwise to lie to the left of the SMA. As growth continues, the midgut herniates into the umbilical cord and the duodenum undergoes an additional 90 degrees of counter-clockwise rotation to lie behind the SMA without any colonic rotation. Rotational arrest in early Stage I, with lengthening of the midgut and no or <90 degree rotation, leads to a non-rotation type of anomaly; in this case, the colon can be found to the left and small intestine to the right of the midline. The mesentery in turn has a narrow base, placing the bowel at risk for midgut volvulus.

Stage II of rotation (10th-12th week of gestation) involves reduction of the physiological umbilical hernia. During this process the DJ loop completes its final 90 degrees counter-clockwise rotation, such that the duodeno-jejunal junction is located to the left of the spine; meanwhile the CC loop rotates counter-clockwise 180 degrees, until the cecum is located in the right lower quadrant of the abdomen. This anatomic arrangement results in a broad diagonal base of mesentery that extends from the left upper quadrant to the right lower quadrant.

These rotational events occur independently, so that failure of the LOT to achieve its normal position is not necessarily associated with CC malrotation and vice versa. Arrest in development during this stage leads to a spectrum of anomalies of incomplete rotation.

Typical malrotation occurs when the DJ loop is fixed to the right of the spine, while the CC loop rotates only 180 degrees to pass in front of the SMA. This leaves the origin and terminal portions of the small bowel mesentery nearly superimposed upon one another at the base of the SMA. The resultant narrow mesenteric base is prone to clockwise twisting, causing acute or chronic small bowel ischemia. This arrangement is commonly associated with the formation of abnormal peritoneal (Ladd’s) bands, which course from the misplaced cecum across the duodenum to the undersurface of the liver or posterior abdominal wall and may result in duodenal obstruction.

Stage III of fixation (12th week of gestation until term) leads to fixation of the LOT to the retroperitoneum in left upper quadrant, the cecum to the right lower quadrant and ascending and descending colon in their normal anatomic retroperitoneal locations. Failure of fixation of either the right or left mesocolon to the retroperitoneum results in mesocolic hernias and predisposes the small intestine to entrapment on either side, which can result in obstruction, incarceration or strangulation.

What laboratory studies should you request to help confirm the diagnosis? How should you interpret the results?

Laboratory studies in the setting of malrotation with an acute volvulus will reveal a high WBC count with neutrophilia and bandemia, metabolic acidosis with low serum bicarbonate (HCO3), with or without a positive stool guaiac test. Chronic atypical presentations may present with low serum albumin levels and electrolyte derangements, depending on the severity and chronicity of symptoms.

Would imaging studies be helpful? If so, which ones?

Plain Abdominal radiograph: Usually the initial study obtained; it is rarely diagnostic. It may reveal air in the stomach and duodenum with a paucity of distal bowel gas (due to partial duodenal obstruction or associated duodenal web), or centralized, dilated bowel loops (due to distal obstruction). In the presence of intestinal ischemia there may be pneumatosis intestinalis and/or portal venous gas. Abdominal radiographs in atypical cases may be completely normal.

Upper GI series: Remains the gold standard for the diagnosis of malrotation with a sensitivity of 93%-100%. Malrotation is diagnosed based on the location of the ligament of Treitz (LOT), which is normally located to the left of the left sided pedicle of the vertebral body at or above the level of the duodenal bulb. Typical malrotation is defined by a LOT that is either absent or to the right of the midline. It may or may not be associated with an abnormal cecal location (See Figure 1). Atypical malrotation is identified when the LOT is either midline or to the left of midline, but does not rise to its usual location at the level of the duodenal bulb, with a variable cecal position.

Figure 1

Upper GI in malrotation showing abnormal location of duodenojejunal junction.

In the setting of malrotation with midgut volvulus, the UGI may show: 1) dilation of the proximal duodenum tapering to a conical or beak shape, 2) a spiral or corkscrew appearance of the distal duodenum (See Figure 2) or 3) a Z shaped configuration of the duodenum in the presence of obstructing peritoneal bands.

Figure 2

Upper GI in malrotation showing abnormal location of duodenojejunal junction with corkscrew appearance of duodenum.

In selected cases, such as gastric distension, indwelling tubes, premature infants, renal agenesis, or splenomegaly, the LOT may appear displaced adding to the challenge of making a correct diagnosis. False positive rates of 15% and false negative rates of 3%-6% have been reported in literature.

Contrast enema: In difficult or equivocal cases, where malrotation cannot be ruled out solely based on an UGI series, a contrast enema may show an abnormally located cecum in the right upper quadrant (See Figure 3). It is also useful in rare cases of isolated colonic malrotation and in the diagnosis of transverse colon volvulus. A barium enema can be normal in up to 40% of cases with confirmed malrotation of the midgut and should not be used as the sole diagnostic modality.

Figure 3

Contrast enema in malrotation showing abnormal location of cecum in epigastrium.

Ultrasonography: Findings on ultrasound suggestive of malrotation include reversal of the normal orientation of the superior mesenteric artery and vein, or the whirlpool sign of midgut volvulus. These findings are neither sensitive nor specific and an UGI series is strongly recommended to confirm the diagnosis in suspected cases.

Computerized Tomography (CT) abdomen: CT has been utilized in recent years due to its ability to demonstrate findings of SMA and SMV reversal, position of the LOT and cecum, bowel viability and evidence of volvulus (whirlpool sign) if present (See Figure 4). An UGI study remains the modality of choice, however, due to the high cost, increased radiation exposure and low specificity and sensitivity associated with CT studies.

Figure 4

CT scan abdomen showing mesenteric whirlpool sign suggestive of malrotation with volvulus.

Confirming the diagnosis

  • Please see attached algorithms 1 & 2 (See Figure 5 and Figure 6).

Figure 5

Algorithm 1: Management of a child with bilious vomiting.

Figure 6

Algorithm 2: Intra-operative management of child with malrotation and volvulus.

If you are able to confirm that the patient has intestinal malrotation with volvulus, what treatment should be initiated?

In 1932, William E. Ladd described the surgical management of malrotation; his classic 1936 article remains a cornerstone for the surgical practice today.

When the diagnosis of malrotation with midgut volvulus is made, resuscitation and laparotomy are performed in rapid succession in order to minimize the duration of intestinal ischemia. The abdomen is entered through a transverse right upper quadrant or upper midline abdominal incision. The volvulus appears as a convoluted jumble of dilated, compromised bowel with a visible twist at the base of the mesentery (See Figure 7).

Figure 7

Intra-operative image showing malrotation with volvulus.

One or more counter-clockwise twists may be necessary to reduce the volvulus. The anatomic situation is then clarified and if the entire bowel appears viable, a Ladd’s procedure is performed. Ladd’s bands are divided between the cecum and the duodenum. The underlying visceral peritoneum over the superior mesenteric artery – medial to the duodenum – is incised to splay out the base of the mesentery. The duodenum is freed up and inspected for an area of narrowing or stenosis; saline may be injected through a transpyloric orogastric tube to confirm duodenal patency in a newborn. The duodenum is led down the right gutter, the small bowel is laid sequentially right to left in the mid-abdomen and the cecum and descending colon are placed on the left side of the abdomen so that the bowel is nonrotated.

Lastly, an appendectomy is performed to avoid future diagnostic confusion. Some have advocated fixation of the duodenum and/or cecum to reduce the risk of recurrent volvulus; this is no longer done, however, because recurrence is uncommon and surgical fixation has led to greater morbidity.

Nonviable portions of bowel (See Figure 8) should be resected at the time of operation. Bowel segments with questionable vascular integrity should be left intact and reexamined in 24 to 36 hours in an effort to preserve bowel length. Questionable areas will declare themselves in that time period, so that stomas or primary anastomoses may be constructed with confidence. Meanwhile, the parents should be apprised of the situation and discussion begun on the long-term prognosis of the child.

Figure 8

Intra-operative image showing malrotation with volvulus with necrotic bowel.

When an abnormality of rotation is discovered intraoperatively or incidentally during diagnostic evaluation for another problem that requires a laparotomy, correction of the malrotation should be carried out at the time of surgery. Similarly, if malrotation is discovered incidentally at the time of evaluation for a condition not requiring surgery, most surgeons recommend correction of the malrotation, regardless of the patient’s age or symptoms. This recommendation is meant to avoid the unpredictable, catastrophic complication of midgut volvulus. An elective Ladd’s procedure is easily performed with minimal morbidity using either open or laparoscopic techniques.

What are the possible outcomes of intestinal malrotation with volvulus?

The mortality of affected newborns has markedly decreased from ~30% in the 1960’s to 2-3% in the current era. The major cause of mortality is associated congenital abnormalities and their complications, not malrotation per se. The incidence of volvulus has been reported to be ~19% in typical malrotation versus <1% in atypical presentations.

What causes this disease and how frequent is it?

The true incidence and prevalence of malrotation are unknown. While most patients present in the neonatal period, many remain asymptomatic well into adult life.

The incidence of malrotation is reported to be 1 in 500 live births.

Slight male predilection (M: F; 1.3:1).

50-75% discovered in the 1st month of life; 90% diagnosed at age < 1 year.

Autopsy studies suggest 0.5-1% of the population is affected.

Many cases are discovered on coincidental GI imaging or at the time of surgery; an unknown number go undetected.

What complications might you expect from the disease or treatment of the disease?

There is significant morbidity and the potential for long term complications in association with malrotation, even after corrective surgery and parents should be appropriately informed and educated. Delay in diagnosis and appropriate surgical therapy can lead to small bowel necrosis, possibly resulting in short bowel syndrome. In many cases, this will mean months, if not years, of parenteral nutrition, continuous enteral feeds via a pump and repeated bouts of line sepsis requiring multiple hospitalizations.

Liver failure is a possibility, depending on the amount and duration of parenteral nutrition. Small bowel and combined small bowel/liver transplants have been performed in children with short bowel syndrome and the results are encouraging; however, this therapeutic choice is fraught with the risks of transplant rejection, recurrent infection and a lifetime of immunosuppression.

Small bowel obstruction due to recurrent midgut volvulus, intussusception, internal hernia or an adhesive band has been reported in 11-24% of patients. Obstructive complications can lead to multiple hospitalizations and further surgery and may be fatal if not recognized in a timely fashion. Patients may also present with prolonged ileus, GERD, chylous ascites, feeding intolerance and/or malabsorption. Delay in recovery of bowel function and occasional non-resolution of symptoms, especially in atypical cases; have been attributed to underlying intestinal dysmotility. Postoperative complications are more common in atypical versus typical malrotation (27% versus 16%).

What is the evidence?

Millar, AJW,, Rode, H,, Cywes, S.. “Malrotation and volvulus in infancy and childhood.”. Semin in Pediatr Surg,. vol. 12. 2003. pp. 229-236.

Nehra, D,, Goldstein, AM. “Intestinal malrotation: Varied clinical presentation from infancy through adulthood.”. Surgery. vol. 149. 2011. pp. 386

Loyer, E,, Eggli, KD. “Sonographic evaluation of superior mesenteric vascular relationship in malrotation.”. Pediatr Radiol. vol. 19. 1989. pp. 173

Applegate, KE,, Anderson, JM,, Klatte, EC.. “Intestinal Malrotation in Children: A Problem-solving Approach to the Upper Gastrointestinal Series.”. Radiographics,. vol. 26. 2006. pp. 1485

Murphy, FL,, Sparnon, AL.. “Long-term complications following intestinal malrotation and the Ladd’s procedure: a 15 year review.”. Pediatr Surg Int. vol. 22. 2006. pp. 326

Gohary, YE,, Alagtal, M,, Gillick, J.. “Long-term complications following operative intervention for intestinal malrotation: a 10-year review.”. Pediatr Surg Int. vol. 26. 2010. pp. 203

Fraser, JD,, Aguayo, P,, Sharp, SW. “The Role of Laparoscopy in the Management of Malrotation.”. Jour of Surg Research,. vol. 156. 2009. pp. 80-82.

Stanfill, AB,, Pearl, RH,, Kalvakuri, K. “Laparoscopic Ladd’s Procedure: Treatment of Choice for Midgut Malrotation in Infants and Children.”. Journal of laparoendoscopic and advanced surgical techniques,. vol. 20. 2010. pp. 369-372.

Lampl, B,, Levin, TL,, Berdon, WE,, Cowles, RA. “Malrotation and midgut volvulus: a historical review and current controversies in diagnosis and management.”. Pediatr Radiol,. 2009. pp. 359-366.

Cullis, PS,, Siminas, S,, Losty, PD. “Is screening of intestinal foregut anatomy in heterotaxy patients really necessary?: a systematic review in search of the evidence.”. Ann Surg. 2015.

Lodwick, DL,, Minneci, PC,, Deans, KJ. “Current surgical management of intestinal rotational abnormalities.”. Curr Opin Pediatr. vol. 27. 2015. pp. 383-8.