Intestinal malrotation in children

INTRODUCTION — An overview of the presentation, diagnosis, and treatment of intestinal malrotation in children will be presented here.

Intestinal malrotation in adults and congenital diaphragmatic hernia and abdominal wall defects are discussed separately. (See "Intestinal malrotation in adults" and "Omphalocele: Prenatal diagnosis and pregnancy management".)

EPIDEMIOLOGY — Rotational anomalies occur as a result of an arrest of normal rotation of the embryonic gut. Because rotational anomalies may remain asymptomatic throughout a person's life span, the true incidence is not known. Nonrotation, a type of malrotation is an incidental finding on approximately 2 out of 1000 upper gastrointestinal contrast studies [1]. Symptomatic malrotation in neonates occurs with a frequency of about 1 in 6000 live births.

Traditionally, intestinal malrotation has been considered primarily a disease of infancy with infrequent occurrence beyond the first year of life [2,3]. However, analysis of over 2700 cases of intestinal rotation in children up to 17 years of age obtained from a national hospital discharge database found the following [2]:

●Presentation by one month of age: 30 percent

●Presentation before one year of age: 58 percent

●Presentation before five years of age: 75 percent

Similarly, in a series of 170 patients of all ages with symptomatic intestinal malrotation managed at a single institution, age distribution at time of presentation was as follows [3]:

●Infants under one year of age: 31 percent

●Children 1 to 18 years of age: 21 percent

●Adults over 18 years of age: 48 percent

Thus, the prevalence of malrotation in children over one year of age and adults may be higher than previously thought.

Associated congenital defects — Over 50 percent of children who have intestinal malrotation have an associated anomaly (table 1) [4-7].

Based upon a systematic review of small, single-institution studies, the following conditions have demonstrated a strong association with intestinal malrotation [8]:

●Congenital diaphragmatic hernia – Up to 100 percent

●Congenital heart disease, especially heterotaxy syndrome – 40 to 90 percent (see 'Screening' below)

●Omphalocele – 31 to 45 percent

Intestinal malrotation is also associated to varying degrees with:

●Gastroschisis (see "Gastroschisis", section on 'Associated anomalies and findings')

●Prune-belly syndrome (see "Prune-belly syndrome", section on 'Abdominal wall musculature')

●Certain types of intestinal atresias [9] (see "Intestinal atresia")

●Esophageal atresia (solitary and with tracheoesophageal fistula) [10]

●Biliary atresia in patients with laterality malformations (see "Biliary atresia", section on 'Types of biliary atresia')

●Meckel diverticulum [11]

●Complex anorectal malformations or anorectal malformations with two or more anomalies of the VACTERL (vertebral, anal, cardiac, tracheoesophageal, renal, limb) complex [12,13]

●Cornelia de Lange syndrome [14]

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 8^th to 10^th 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 (figure 5 and 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.

CLINICAL PRESENTATION — The primary clinical findings in infants and young children with intestinal malrotation with obstruction and/or volvulus include [1,3]:

●Vomiting, typically bilious (green or fluorescent yellow) but can be nonbilious, especially in neonates and young infants

●Abdominal pain (most common symptom in older children; may be out of proportion to the examination)

●Hemodynamic instability from hypovolemia and/or septic shock

●Abdominal distension (not always present, especially in young infants)

●Abdominal tenderness (can be difficult to elicit, especially in infants and young children)

●Peritonitis (eg, rigid abdomen) indicating volvulus with perforation (rare)

●Hematochezia indicating bowel ischemia and possible necrosis due to volvulus (rare)

Bilious vomiting in an infant should immediately raise suspicion of malrotation with midgut volvulus and prompt an emergency evaluation to either confirm or rule out that diagnosis. (See 'Diagnosis' below.)

In older children, the clinical presentation of malrotation is variable and often insidious [3,17-22]. The most common symptom is abdominal pain which may be out of proportion to the examination [3]. Vomiting is also frequently present but may not be bilious; and both abdominal pain and vomiting may be intermittent [3,15].

Other, less common presentations for intestinal malrotation include [6,23-27]:

●Poor weight gain

●Solid food intolerance

●Malabsorption

●Chronic diarrhea from protein-losing enteropathy

●Pancreatitis

●Biliary obstruction

●Gastrointestinal (GI) motility disorder

●Chylous ascites

Older children with chronic symptoms may have been previously diagnosed with other chronic GI disorders, such as allergy, irritable colon, functional abdominal pain, or cyclic vomiting [18,28,29].

A significant number of children with malrotation and associated anomalies (table 1) may be asymptomatic. (See 'Associated congenital defects' above.)

Anatomic features of malrotation lead to the clinical symptoms resulting from volvulus or duodenal obstruction [1]:

●Volvulus – Approximately one-third of children with malrotation present before one month of age with the life-threatening complication of volvulus [15]. Volvulus occurs when small bowel twists around the superior mesenteric artery resulting in small bowel ischemia to large portions of the midgut (figure 5). This leads to ischemia and necrosis of the bowel that becomes irreversible, unless quickly corrected.

Vomiting, which may or may not be bilious, occurs in >90 percent of newborns with volvulus and is by far the most common presenting symptom of malrotation in infancy [3]. Third space fluid losses and sepsis, caused by necrotic bowel, can cause rapidly progressive cardiovascular compromise. Prompt fluid resuscitation and emergency surgical intervention are essential. (See 'Malrotation with volvulus' below.)

Approximately 22 percent of older children and 12 percent of adults with malrotation present with volvulus [3]. The onset of symptoms is usually acute, but some children present with a more chronic pattern of episodic vomiting and abdominal pain suggestive of intermittent volvulus over the course of weeks to months to years [3,30]. (See "Intestinal malrotation in adults", section on 'Acute clinical presentation'.)

●Duodenal obstruction – In neonates, malrotation can also present as duodenal obstruction. The obstruction may be caused by Ladd bands which cross the duodenum (figure 5) or associated duodenal atresia or stenosis and results in bilious vomiting without abdominal distension.

The clinical presentation of intestinal malrotation in adults is discussed separately. (See "Intestinal malrotation in adults", section on 'Clinical presentation'.)

DIAGNOSIS

Clinical suspicion — The diagnosis of intestinal malrotation should be suspected in any infant who presents with bilious emesis, acute duodenal obstruction, or abdominal tenderness associated with hemodynamic deterioration [31]. In a case series of 52 infants under one year of age, vomiting was the presenting symptom in 93 percent of patients with malrotation and midgut volvulus [3].

Any vomiting in patients with anomalies that are known to be associated with intestinal malrotation (table 1) should also raise concern for malrotation.

In older children and adults, abdominal pain is the most common symptom and may present with abrupt onset over hours or days or as chronic intermittent pain over weeks, months, or years [3,31]. Intermittent vomiting, chronic diarrhea, malabsorption, or poor weight gain comprises other potential presenting symptoms [1,3,26]. (See "Intestinal malrotation in adults", section on 'Clinical presentation'.)

Diagnostic approach — The diagnostic approach to intestinal malrotation is described in the algorithm (algorithm 1).

Unstable patients — When malrotation is complicated by volvulus or perforation with peritonitis, it is a potentially life-threatening condition and requires emergency evaluation and treatment (algorithm 1). If the patient has volvulus with signs of peritonitis (eg, abdominal tenderness with abdominal distension and rigidity, hematemesis, hematochezia, and/or shock), the patient should be rapidly resuscitated and immediately taken to surgery for exploration. No additional evaluation is required although some surgeons may obtain emergency imaging. (See 'Surgical treatment' below.)

Stable patients — If a patient with suspected malrotation is hemodynamically stable and without clear signs of intestinal compromise, the diagnosis should be confirmed by radiologic evaluation (algorithm 1 and table 2). This evaluation typically begins with abdominal ultrasonography (US) in many institutions, and, if US is equivocal or negative, a limited upper gastrointestinal (GI) series to visualize the duodenum. Obtaining a limited upper GI series as the initial study is an acceptable alternative. Radiographic findings suggestive of malrotation are listed in the table (table 2) and discussed below. Radiologists carrying out these studies should have experience with performance and interpretation of US and upper GI series in children.

●Ultrasonography – US is used as the initial examination for both screening and diagnosis in many institutions [32-35]. US may be diagnostic for malrotation without volvulus but is more specific and sensitive for the diagnosis of volvulus [36]. If the US is positive for volvulus, the patient should be taken directly to surgery without further imaging. If the diagnosis is not clear, a limited upper GI series to view the duodenum should be performed under fluoroscopy by an experienced pediatric radiologist [8,37].

On the other hand, a normal US does not exclude malrotation [38]. For example, in two large retrospective series, 2 to 3 percent of children with normal US evaluations had malrotation diagnosed with upper GI series [39,40]. Intraluminal saline, particularly in patients with duodenal obstruction, may improve diagnostic accuracy [35,41]. Thus, patients with suspected malrotation who have negative or indeterminate findings by US should undergo an upper GI series.

Ultrasonographic findings that are suggestive of malrotation include:

•Third part of the duodenum is not in the normal retromesenteric position (ie, located between the mesenteric artery and the aorta in the retroperitoneal space) [42]

•Abnormal position of the superior mesenteric vein (either anterior or to the left of the superior mesenteric artery [SMA]) [39,43]; the superior mesenteric vein is normally located to the right of the SMA

•The "whirlpool" sign of volvulus (caused by the vessels twisting around the base of the mesenteric pedicle) [36,39,44]

•Dilated duodenum (indicating duodenal obstruction by Ladd bands) [44]

•Duodenal obstruction with distal air

●Upper GI series – Given the grave consequences of missing the diagnosis, upper GI series in children remains the gold standard for diagnosing malrotation. Although US, barium enema, and plain radiographs can be useful adjuncts when abnormal findings are present, normal findings do not exclude malrotation.

The sensitivity of a limited upper GI series in infants with signs of malrotation is approximately 96 percent [45]. In approximately 25 percent of cases, the upper GI findings are subtle, and the radiographic diagnosis may be difficult [46-48]. However, in the remaining 75 percent of cases, the signs of malrotation are obvious. These findings include:

•A clearly misplaced duodenum with the ligament of Treitz on the right side of the abdomen

•A duodenum with a "corkscrew" appearance (image 2 and image 3)

•Duodenal obstruction, which may appear similar to that seen with duodenal atresia (dilated stomach and proximal duodenum (image 4))or may present with a "beak" appearance if a volvulus is present.

The false-negative and -positive rates of upper GI series in the diagnosis of malrotation are approximately 6 to 14 percent and 7 to 15 percent, respectively [49]. When the limited upper GI series is equivocal and there is a high index of suspicion or signs of distal bowel obstruction, it may be helpful to add small bowel follow-through, repeat the study when the patient is symptomatic [50], or evaluate colonic rotation with a barium enema [46,47].

●Plain radiographs – Plain radiographs are rarely helpful in the diagnosis of malrotation and/or volvulus. In patients with volvulus, the plain radiograph typically shows a gasless abdomen but may show only mild intestinal dilatation or may be completely normal (image 5). Findings that are diagnostic on plain film include:

•A naso- or orogastric tube that extends into an abnormally positioned duodenum.

•The "double-bubble" sign with distal gas present. Absence of distal gas in a newborn with a double-bubble sign is more likely duodenal atresia, but this diagnosis is associated with malrotation in 17 percent of patients (image 6); partial obstruction of the duodenum causes distension of the stomach and first part of the duodenum.

●Barium enema – Barium enema may be misleading and should not be used for the diagnosis of malrotation. Because the final fixation of the colon does not occur until near term, many newborns have a high or poorly-fixed cecum, which can mimic malrotation and result in a false-positive study [37]. Conversely, in approximately 20 percent of cases of malrotation, the cecum is normally located in the right lower quadrant (false-negative) [51,52]. Occasionally, malrotation appears as an incidental finding in adults undergoing barium enema (image 7).

In patients with volvulus due to malrotation, there may be a complete cutoff of the transverse colon on barium enema with a beaked appearance of the head of the barium column (image 8) [53].

●Computed tomography – Although not the best test for confirming intestinal malrotation, computed tomography of the abdomen may provide the diagnosis of malrotation when it is performed for other reasons. Diagnostic findings include (table 2) [54]:

•The third part of the duodenum does not pass between the mesenteric artery and the aorta.

•The proximal small bowel is mostly located to the right of the midline.

•There is an abnormal position of the superior mesenteric vein and superior mesenteric artery.

•A "whirlpool" sign is present indicating twisting of blood vessels around the mesenteric pedicle (image 9).

●Magnetic resonance imaging – Magnetic resonance imaging (MRI) can be used to diagnose intestinal malrotation, especially when ionizing radiation is contraindicated (eg, pregnant patients) [55]. It has also been reported as a means of diagnosing fetal intestinal malrotation [56]. However, experience is limited and practical matters (eg, emergency access to MRI, need for sedation in infants and children, and length of the study) limit its usefulness in clinical circumstances where volvulus is a concern.

Patients with equivocal findings on imaging — Laparoscopy is a less invasive option than laparotomy for determining the presence of volvulus in children for whom diagnostic imaging is equivocal or suggests malrotation without volvulus. For example, in a case series of children with a median age of 18 months (range four days to 16 years) who were undergoing evaluation for malrotation, 13 of 24 patients with a preoperative diagnosis of malrotation without volvulus had volvulus on laparoscopy, 3 of these 24 patients had normal rotation, and 6 of 19 patients with equivocal imaging findings had malrotation discovered by laparoscopy [57].

SCREENING — The approach to screening of infants with heterotaxy syndrome is discussed separately. (See "Heterotaxy (isomerism of the atrial appendages): Management and outcome", section on 'Surgical repair for intestinal malrotation'.)

Patients with other congenital defects associated with malrotation such as congenital diaphragmatic hernia or abdominal wall defects usually have a form of nonrotation which places them at low risk for midgut volvulus. Thus, these patients do not warrant screening unless there are symptoms such as feeding intolerance, vomiting, or pain, which might suggest obstruction or intermittent volvulus.

DIFFERENTIAL DIAGNOSIS — The differential diagnosis of intestinal malrotation depends upon the age of the patient and the cardinal signs and symptoms. It includes other causes of intestinal obstruction, vomiting, and acute abdomen [6]:

●Necrotizing enterocolitis (NEC) – In young premature infants, the presentation of NEC may be difficult to distinguish from malrotation. However, the majority of infants with NEC have characteristic radiograph features present on plain abdominal radiograph (image 10). (See "Neonatal necrotizing enterocolitis: Clinical features and diagnosis", section on 'Abdominal radiography'.)

●Intussusception – In older infants, intussusception also frequently is associated with bilious vomiting, abdominal distension, blood in the stool, and nonspecific findings on abdominal plain films. US of the abdomen will show the "bull's eye" or "coiled spring" lesions that indicate layers of intestine within intestine (image 11). (See "Intussusception in children", section on 'Ultrasonography'.)

●Other causes of abdominal pain or vomiting – In children, differential diagnostic considerations also include a variety of illnesses which can present with abdominal pain or vomiting. If a volvulus is present, the differential includes perforated viscus, appendicitis, or other causes of peritonitis. Differentiating among these various conditions is discussed in more detail separately. (See "Emergency evaluation of the child with acute abdominal pain" and "Approach to the infant or child with nausea and vomiting".)

SURGICAL TREATMENT

Indications and surgical approach — Malrotation is treated surgically in almost all children. The Ladd procedure is the standard approach and consists of widening the base of the mesentery, placing the bowel in a position of nonrotation, and creating adhesions that "hold" the intestines in place. This makes subsequent volvulus less likely. Incidental appendectomy is also performed at the time of the Ladd procedure in most children. (See 'Appendectomy' below.)

The patients' condition and the presence of volvulus determines the approach (algorithm 1):

●Malrotation with volvulus – Regardless of the presence of symptoms, these patients require emergency laparotomy, detorsion of the volvulus, and the Ladd procedure. (See 'Malrotation with volvulus' below.)

●Malrotation without volvulus – Surgery is suggested for all patients with symptoms. Timing of the procedure and choice of surgical approach (laparotomy versus laparoscopy) depends upon patient characteristics and comorbidities as well as the surgeon's preference. (See 'Clinical presentation' above and 'Malrotation without volvulus' below.)

Evidence is lacking regarding the best approach to asymptomatic children with malrotation discovered incidentally on imaging. For most patients with low surgical risk, we suggest surgical repair. Watchful and informed waiting, especially in children with comorbidities that increase their surgical risk is appropriate after discussion with a pediatric surgeon. (See 'Malrotation without volvulus' below.)

Malrotation with volvulus — All patients with intestinal malrotation and volvulus on imaging or suspected based upon clinical presentation should proceed directly to emergency laparotomy (algorithm 1) [8].

Preoperative management includes:

●Fluid resuscitation

●Treatment of septic shock, as needed

●Placement of an oro- or nasogastric tube for decompression

●Administration of broad-spectrum antibiotics to cover bowel flora (eg, piperacillin-tazobactam or ceftriaxone and metronidazole)

At the time of surgical exploration, if a volvulus is present, it is untwisted in a counterclockwise fashion. In addition, the Ladd procedure for correction of malrotation consists of:

●Division of the Ladd bands (figure 5 and picture 1), if present.

●Widening of the base of the mesentery by dividing any adhesions between the duodenum and cecum at the base of the mesentery.

●In the neonate, passing a tube through the duodenum to rule out any associated duodenal obstruction.

●Placing viable bowel in a position of nonrotation (ie, small bowel on the right and colon on the left). If the viability of the bowel is in question, the abdomen can be closed and the bowel re-evaluated after 24 to 36 hours. If frankly necrotic bowel is present, it is resected and stomas are created.

Malrotation without volvulus — For patients with malrotation without volvulus, management depends upon the presence of symptoms:

●Symptomatic – For symptomatic children with symptoms (such as vomiting, abdominal pain, and/or poor weight gain) and malrotation without volvulus, we suggest surgical treatment. The choice of surgical approach (laparotomy or laparoscopy) depends upon patient characteristics and the surgeon's preference, a Ladd procedure for malrotation can be performed laparoscopically, particularly in the older child, but may have a higher risk of postoperative volvulus than open surgery. (See 'Laparoscopy' below.)

●Asymptomatic – Evidence is lacking regarding the best approach to "asymptomatic" malrotation discovered incidentally on imaging studies [8]. For most children at low surgical risk, we suggest elective surgical repair. Although most patients with volvulus present in the newborn period, it is not clear that the risk of volvulus decreases with age [3,15,21,23,49]. It is also difficult to determine with imaging studies whether a child with a rotational anomaly has a narrow-based mesentery, which increases the risk of volvulus. Watchful and informed waiting, especially in children with comorbidities that increase their surgical risk, is appropriate after discussion with a pediatric surgeon [58,59]. Given the risk of complications associated with a Ladd procedure in infants with uncorrected severe congenital heart disease, delaying the procedure until after cardiac palliation appears prudent. The surgical repair of asymptomatic malrotation in children with heterotaxy is discussed separately. (See "Heterotaxy (isomerism of the atrial appendages): Management and outcome", section on 'Surgical repair for intestinal malrotation'.)

The use of laparoscopy to assess the mobility of the colon and the width of the mesentery has been advocated by some surgeons for the evaluation of malrotation in asymptomatic patients [23,60,61]. In patients with narrow mesenteric attachment and potential colonic mobility, a Ladd procedure can then be undertaken. By contrast, patients with atypical malrotation and a wide mesenteric base (ligament of Treitz at or to the left of midline but below the pylorus) can be observed [8].

Laparoscopy — In patients with malrotation without volvulus, the Ladd procedure can be performed laparoscopically, particularly in the older child without comorbidities [3,8,60-64]. Approximately one-quarter of patients undergoing laparoscopic Ladd procedure convert to an open procedure during the operation [65]. While laparoscopic surgery for malrotation is associated with greater patient comfort, a shorter length of hospital stay, and fewer operative complications, this approach remains controversial due to a potentially higher risk of volvulus after laparoscopic surgery when compared with open surgery [65,66]. It has been suggested that the laparoscopic approach may be associated with a higher recurrence rate of volvulus because of fewer adhesions after surgery [23,65,66]. For example, in one multicenter, retrospective review of 227 patients with malrotation with volvulus, patients were more likely to experience a recurrent volvulus if they underwent a laparoscopic Ladd procedure compared with open surgery (13 versus 0 percent, p = 0.04) [66]. In a separate metanalysis of nine observational studies, recurrent volvulus occurred in 3.5 percent of 259 patients who had a laparoscopic Ladd procedure compared with 1.4 percent of 744 patients who had an open procedure [65]. However, there have been no prospective studies to compare laparoscopic and open correction of malrotation, and the limited evidence from observational studies is inconsistent [8,64,66].

Appendectomy — Although appendectomy was not described as part of the original Ladd procedure, it is commonly performed in patients undergoing surgery for malrotation. This practice originated during an era where imaging was not available and an abnormally positioned appendix could mislead clinicians, an issue that is no longer pertinent. However, evidence suggests lower lifetime cost in healthy, young patients undergoing incidental appendectomy, supporting this continued approach [67].

On the other hand, particularly for children with any potential need for urological reconstruction such as bladder augmentation or antegrade colonic enemas for recurrent fecal obstruction distal to the ileo-cecal valve, leaving the appendix in place may be more appropriate [68]. In addition, as new information about the effect of appendectomy on the microbiome is published, there may be additional changes in our understanding of the risk to benefit ratio for prophylactic appendectomies [69].

Complications — Complications of the Ladd procedure are unusual in the absence of compromised bowel from volvulus. Patients with a volvulus may have short bowel syndrome if bowel resection is required and are at risk for small bowel obstruction.

Short bowel syndrome — Resection of a larger percentage of small bowel and the ascending colon may be necessary in patients with malrotation and midgut volvulus if necrotic bowel is present at the time of surgery. In one series of 68 consecutive children who had a Ladd procedure for malrotation, midgut volvulus was present in 40, and among these, gangrenous bowel was present in 3 (7.5 percent) [70]. Of these, one died, and two had short bowel syndrome. This complication is only preventable through prompt recognition and management of malrotation and midgut volvulus.

Small bowel obstruction — After any laparotomy, patients are at risk for small bowel obstruction from adhesions. This complication has been reported in up to 15 percent of patients in some series [22,49].

OUTCOMES

Resolution of symptoms — Resolution of symptoms occurs in up to 89 percent of patients who undergo operative intervention [3]. Persistent symptoms postoperatively are less common in infants, children under 18 years of age, and patients with malrotation and volvulus. In contrast, only 4 of 12 symptomatic patients who did not receive operative intervention had resolution of symptoms in one observational study [3].

Mortality — The overall mortality rate after surgery for malrotation ranges from 3 to 10 percent [20,71-73]. Mortality is increased in patients with volvulus, intestinal necrosis, prematurity, and associated anomalies [20,71], and approaches zero in otherwise healthy children without intestinal ischemia.

Recurrent volvulus — In a meta-analysis of nine observational studies, the risk of recurrent volvulus after laparoscopic versus open Ladd procedure was 3.5 and 1.4 percent, respectively [65]. The Ladd procedure for malrotation reduces the risk of recurrent volvulus by widening the base of the mesentery (and presumably causing some adhesions). However, this risk is not eliminated because the underlying embryologic defect has not been corrected.

SUMMARY AND RECOMMENDATIONS

●Embryology and pathogenesis – Rotational anomalies occur as a result of an arrest of normal rotation of the embryonic gut. They are often associated with other abnormalities (table 1) but can also occur in otherwise healthy children and adults. (See 'Embryology and pathogenesis' above.)

●Clinical presentation – The primary clinical findings in infants and young children with intestinal malrotation with obstruction and/or volvulus include:

•Vomiting, typically bilious (green or fluorescent yellow) but can be nonbilious (most common presenting symptom in neonates and young infants)

•Abdominal pain (most common symptom in older children; may be out of proportion to the examination)

•Abdominal tenderness (can be difficult to elicit, especially in infants and young children)

•Hemodynamic instability from hypovolemia and/or septic shock

•Abdominal distension (not always present, especially in young infants)

•Peritonitis (eg, rigid abdomen) indicating volvulus with perforation (rare)

•Hematochezia indicating bowel ischemia and possible necrosis due to volvulus (rare)

Bilious vomiting in any infant <1 year old is a surgical emergency until malrotation is ruled out. Abdominal distension, abdominal wall rigidity, hematemesis or hematochezia, and/or shock represent signs of severe bowel ischemia in patients with volvulus. (See 'Clinical presentation' above and 'Clinical suspicion' above.)

The presentation of intestinal malrotation in older children is variable and often insidious. These patients may also present with acute onset of bilious vomiting and obstruction due to midgut volvulus. However, they more often have intermittent vomiting or abdominal pain. Less common presentations include poor weight gain, solid food intolerance, malabsorption, chronic diarrhea, pancreatitis, peritonitis, biliary obstruction, motility disorders, or chylous ascites. (See 'Clinical presentation' above.)

A significant number of children with malrotation and associated anomalies (table 1) may be asymptomatic. We suggest that asymptomatic infants with heterotaxy syndrome undergo radiologic screening for intestinal malrotation with an upper gastrointestinal (GI) series with oral contrast. (See 'Screening' above and 'Malrotation without volvulus' above.)

●Diagnostic approach – Patients with acute findings of malrotation with volvulus require emergency consultation with a pediatric surgeon as soon as the diagnosis is considered and undergo rapid diagnostic evaluation and surgical treatment as described in the algorithm (algorithm 1):

•Unstable patients – If signs of perforation are present on examination, the patient should be rapidly resuscitated and undergo emergency surgery. (See 'Unstable patients' above.)

•Stable patients – For the child with suspected malrotation with volvulus, abdominal ultrasound (US) is the initial imaging study in many institutions. However, if US is negative or indeterminate for volvulus, a limited upper GI series with visualization of the duodenum should be performed. Obtaining a limited upper GI series as the initial study is an acceptable alternative. Radiographic findings suggestive of malrotation are listed in the table (table 2). Radiologists carrying out the procedure should have experience with the performance and interpretation of these studies in children. (See 'Diagnosis' above.)

●Surgical treatment – Malrotation requires surgery in almost all patients. The patients' condition and the presence of volvulus determines the approach:

•Malrotation with volvulus – Children who have malrotation with volvulus require emergency laparotomy, volvulus detorsion, and a Ladd procedure. If, after surgical reduction of a volvulus, the viability of the bowel is in question, temporary abdominal closure with a planned second look procedure can be performed after 24 to 36 hours. If frankly necrotic bowel is present, then it is resected and stomas are created. (See 'Malrotation with volvulus' above.)

•Malrotation without volvulus – For children with symptoms such as vomiting, abdominal pain, and/or poor weight gain and malrotation without volvulus, we suggest prompt surgical repair (Grade 2C). The choice of surgical approach (laparotomy or laparoscopy) depends upon patient characteristics and the surgeon's preference. A Ladd procedure can be performed laparoscopically in patients without volvulus or bowel ischemia, particularly in the older child, but may have a higher risk of postoperative volvulus than open surgery, possibly due to fewer postoperative adhesions. (See 'Laparoscopy' above.)

For most asymptomatic patients with low surgical risk and malrotation discovered incidentally on imaging, we suggest elective surgical repair (Grade 2C). (See 'Malrotation without volvulus' above.)