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394 Intestinal Malrotation and Midgut Volvulus

ment of the loop to the posterior abdominal wall, extending from the presenting with malrotation had clinical evidence of malnutrition. 12
ligament of Trietz to the ileocecal junction. With malfixation, the dis- Physical Examination
tance between these two points of attachment may become shortened,
leaving the midgut loop hanging on a narrow and unstable pedicle that There are often very few, if any, diagnostic physical exam findings with
easily predisposes to twisting (volvulus) and strangulation. malrotation and midgut volvulus. Late presentations may have abdomi-
nal distention and abdominal tenderness, and some patients may have
Ladd’s bands haemodynamic instability if bowel necrosis and sepsis have occurred.
When the caecum has failed to descend from the right upper quadrant The herald sign is bilious emesis and requires prompt diagnostic studies
to the right iliac fossa, anomalous fixation may occur, whereby dense in order to prevent bowel ischaemia and necrosis.
fibrous bands (Ladd’s bands) extend from the caecum and right colon
across the duodenum to the retroperitoneum of the right upper quadrant. Investigations
These bands may cause duodenal obstruction via extrinsic compres- Imaging
sion; however, the obstruction of the duodenum is most commonly It is reasonable to start with abdominal radiographs as the initial
caused by torsion at the base of the midgut mesentery. Bands may evaluation of a patient with biliary emesis or suspected malrotation.
also form between the colon and the duodenum, drawing them closer Patients should have two views of the abdomen: an anteroposterior
together and predisposing the midgut towards volvulus. supine view and either an anteroposterior upright view or a cross-
Mobile caecum table lateral view. Rarely do the radiographs suggest the diagnosis
Failure of fixation of the caecum to the posterior abdominal wall results of malrotation. Instead, they help to exclude other aetiologies for the
in a floating caecum that may predispose to cecal volvulus. patient’s symptoms and serve to guide further imaging. The most
common bowel gas pattern in the setting of malrotation is normal.
Internal hernias
Findings suggestive of an abnormal location of bowel include
Failure of fixation of the mesentery of the duodenum, right colon, or
• the presence of proximal small bowel on the right; and
left colon may result in the formation of potential spaces for internal
or mesocolic hernias. Internal hernias are associated with partial bowel • a disproportionate dilatation of the duodenum with a “double
obstructions, as there may be recurrent entrapment of bowel, which bubble”—this may be seen with severe duodenal obstruction due to
may eventually lead to obstruction and strangulation. 5 volvulus or bands. 1
Other Associated Anomalies Upper Gastrointestinal Series
Malrotation may be present in patients with heterotaxy syndrome An upper gastrointestinal (UGI) series is the preferred test for radio-
(asplenia or right isomerism and polyspenia or left isomerism). Patients graphic diagnosis of malrotation and volvulus (Figures 65.1 and 65.2).
presenting with this syndrome should be investigated for the possibil- It is usually performed with barium, except in cases of a very sick infant
ity of malrotation. Malrotation may also be seen in conjunction with or child in whom the presence of infarcted bowel or perforation is pos-
intestinal atresias and may be the cause for developing atresias in some sible, in which case water-soluble contrast is used. It is important to
of these patients. Vecchia et al., in a large series, found that 28% of document the first bolus of contrast medium through the duodenum in
infants with duodenal atresias had malrotation and 19% of infants with the anteroposterior as well as the lateral projection. This can be done by
jejunoileal atresia had malrotation. 8 quickly rotating the patient to the lateral position once the duodenojeju-
1
Clinical Presentation nal junction is reached. The main radiographic signs of malrotation are
The classic presentation of malrotation with acute midgut volvulus • lateral radiograph suggesting that the distal duodenum is not attached
is a neonate with bilious emesis. The point of obstruction is typically in the retroperitoneum;
beyond the ampulla of Vater, as demonstrated by the bilious emesis. • low or medial position of the duodenojejunal junction;
However, this symptom is not synonymous with the diagnosis of
malrotation. A majority (around 60%) of infants with bilious emesis • spiral “corkscrew” or Z-shaped course of the duodenum and proxi-
will prove to have no anatomic obstruction, but imaging is necessary mal jejunum; and
to exclude the potentially catastrophic event of midgut volvulus as a • location of the proximal jejunum in the right abdomen.
consequence of malrotation. Most patients with malrotation and many
with volvulus have a normal history and have a normal physical exam.
Other acute symptoms that may occur with malrotation are intermittent
abdominal pain, diarrhoea, constipation, and haematochezia. The latter
involves 10–15% of patients and is associated with a poorer prognosis
because it is indicative of bowel ischemia).9 Patients presenting with
peritonitis, abdominal distention, bloody stools, and haemodynamic
instability (signs and symptoms of shock) have a much worse progno-
sis; the clinician may be misled from the diagnosis of malrotation with
volvulus due to the other symptoms related to sepsis..
Malrotation may present in an insidious manner with chronic
symptoms that develop over days, months, and even years. In one
series by Spigland et al., when malrotation presented beyond the
10
neonatal period, the delay in diagnosis was a mean of 1.7 years.
Chronic symptoms include intermittent pain, intermittent vomiting,
malabsorption, and failure to thrive. Patients may be chronically
misdiagnosed with other abdominal pain syndromes, “cyclic vomiting,”
11
or even psychologic disorders. Howell et al. noted that 70% of children
Figure 65.1: UGI depicting malrotation with abnormally low position of the
ligament of Treitz.