Rotación
Rotación
A b n o r m a l i t i e s a n d Mi d g u t
Vo l v u l u s
Jacob C. Langer, MD
KEYWORDS
Malrotation Nonrotation Heterotaxia Intestinal obstruction Bilious vomiting
KEY POINTS
Rotation abnormalities represent a spectrum from non-rotation to normal rotation.
Malrotation may result in lethal midgut volvulus. Any child with bilious vomiting must be
assumed to have midgut volvulus until proven otherwise.
The gold standard for the diagnosis of a rotation abnormality is an upper gastrointestinal
contrast study looking for the location of the duodenojejunal junction.
A laparoscopic approach is useful for children without midgut volvulus. Infants, and older
children with suspected midgut volvulus should undergo laparotomy.
Intestinal rotation occurs during the fourth through twelfth weeks of gestation.1 During
the fourth to fifth week postconception, the straight tube of the primitive embryonic
intestinal tract begins to elongate more rapidly than the embryo, causing it to buckle
ventrally and force the duodenum, jejunum, ileum, and the ascending and transverse
colon to extend into the umbilical cord. The duodenum curves downward and to the
right of the axis of the artery, initially completing a 90 counterclockwise turn. Over the
next 3 weeks, the duodenum continues to rotate so that, by the end of 8 weeks, it has
Division of General and Thoracic Surgery, Hospital for Sick Children, University of Toronto,
Room 1524, 555 University Avenue, Toronto, Ontario M5G1X8, Canada
E-mail address: jacob.langer@sickkids.ca
Box 1
Signs and symptoms of intestinal rotation abnormalities
Nonrotation
Asymptomatic
Associated motility disorder
Associated condition (eg, abdominal wall defect, diaphragmatic hernia, heterotaxia)
Appendicitis in abnormal location
Malrotation without volvulus
Asymptomatic
Bilious vomiting caused by Ladd bands or associated duodenal web
Associated medical condition (eg, heterotaxia syndrome)
Appendicitis in abnormal location
Malrotation with volvulus
Bilious vomiting
Abdominal pain
Hematochezia
Peritonitis
Death
Malrotation with partial or intermittent volvulus
Protein-losing enteropathy
Abdominal pain
Failure to thrive
Malnutrition
Occult gastrointestinal bleeding
undergone 180 rotation. During the tenth gestational week the intestines return to the
abdomen. The cecum is the final portion of the intestine to return and does so by
rotating superiorly and anteriorly around the superior mesenteric artery (SMA). This
sequence of return causes the duodenum and proximal jejunum to be pushed supe-
riorly and to the left posterior to the SMA so that they become fixed in a 270 rotation
from their initial position. Fixation of the intestines in this position takes place over the
fourth and fifth months of gestation.
CLINICAL PRESENTATION
Fig. 1. (A) Normal intestinal rotation, (B) malrotation without volvulus, (C) malrotation with
volvulus, (D) nonrotation.
RADIOLOGIC DIAGNOSIS
Prenatal diagnosis of isolated rotational abnormality is very uncommon, but fetal ultra-
sonography may show the sequelae of prenatal midgut volvulus, such as bowel dila-
tation, meconium peritonitis, and/or fetal ascites.
Postnatally, most children with vomiting have plain abdominal radiography, which is
nonspecific for the diagnosis of rotation abnormalities. Proximal obstruction caused
by Ladd bands, incomplete volvulus, or associated duodenal atresia or web may pre-
sent with a double bubble and a paucity of distal air. Infants with established intestinal
ischemia may have pneumatosis intestinalis, which may lead to confusion with a diag-
nosis of necrotizing enterocolitis. Although unusual, a pattern of distal bowel obstruc-
tion consisting of multiple dilated bowel loops with air-fluid levels may be seen. Most
importantly, children with rotation abnormalities, including malrotation with volvulus,
may initially present with a normal bowel gas pattern (Fig. 2).
The current gold standard for the diagnosis of a rotation abnormality is upper
gastrointestinal contrast radiography (UGI) to evaluate the position of the DJJ, which
should be located to the left of the vertebral body at the level of the inferior margin of
the duodenal bulb on an anteroposterior projection and must travel posteriorly on the
lateral projection.3 If the DJJ does not show these radiographic characteristics, a diag-
nosis of rotation abnormality should be entertained. However, conditions such as
splenomegaly, renal or retroperitoneal tumors, gastric overdistension, liver transplant,
small bowel obstruction, and scoliosis may cause the DJJ to be medially or inferiorly
displaced. The group at the University of Arkansas attempted to define risk of malro-
tation, ischemic volvulus, and internal hernia in a group of consecutive patients under-
going operation for rotation abnormalities based on the positioning of the DJJ on initial
UGI series.4 The rotation abnormality was described as typical if the DJJ was posi-
tioned to the right of the midline or if it was absent, and atypical if the DJJ was at or
to the left of the midline and the DJJ was low-lying. At the time of operation, volvulus
had occurred in 12 of 75 typical patients versus 2 of 101 atypical patients. Internal her-
nias were also more common in typical than in atypical patients. Moreover, this group
found that 11% to 13% of atypical patients had persistent postoperative symptoms
compared with 0% of typical patients. Given the cited postoperative bowel obstruc-
tion rate following Ladd procedure (8%–12%) and the fairly high incidence of
continued symptoms, the investigators advocated careful discussion in patients
with atypical radiological findings. In this group a laparoscopic approach might be
particularly useful (discussed later).
If the UGI is confusing or equivocal, a small bowel follow-through or a contrast
enema to visualize the cecum should also be done. A short distance between the
DJJ and the cecum strongly suggests the presence of malrotation with a narrow-
based mesentery, and therefore a risk of midgut volvulus. However, there is a wide
range of variability in normal cecal positioning and fixation, especially in neonates,
and therefore a cecum located in the right lower quadrant cannot definitively rule
out malrotation, and a cecum located in the right upper quadrant or epigastrium is
not diagnostic of malrotation. Examples of contrast studies in the diagnosis of intes-
tinal rotation abnormalities are shown in Fig. 3.
More recently, identification of an abnormal orientation of the SMA and SMV on ul-
trasonography has been advocated as a noninvasive way to screen for malrotation.5 In
addition, the presence of a whirlpool sign on Doppler ultrasonography has been corre-
lated with the presence of midgut volvulus. However, the sensitivity and specificity of
ultrasonography are not sufficient for it to replace UGI for a definitive diagnosis. In chil-
dren with peritonitis who are too unstable to have UGI, in which midgut volvulus is part
152 Langer
Fig. 2. The varying appearances of malrotation on plain film. (A) Gasless abdomen with
dilated gastric bubble; (B) dilated small bowel suggestive of a distal obstruction; (C) normal
film with slightly dilated duodenum.
Fig. 3. UGI series with small bowel follow-through. (A) Normal contrast study showing the
duodenal C loop crossing the midline. (B) Lateral view of malrotation, showing corkscrew
appearance of jejunum. (C) Lateral view suggestive of duodenal obstruction secondary to
Ladd bands or volvulus. (D) False-positive study; duodenal-jejunal junction is pushed right-
ward by large multicystic kidney.
tube, and taken for an emergent exploratory laparotomy even without a radiological
diagnosis.
SURGICAL TECHNIQUE
The operative correction of malrotation was initially described by William Ladd, and
has changed little since then. Most surgeons begin an open approach to a Ladd pro-
cedure via a transverse supraumbilical incision with the patient placed in the supine
position. In neonates a circumumbilical omega incision affords the same access to
the midgut and mesentery with a considerable cosmetic benefit.6 On entering the
abdomen, rotation and fixation of the bowel are assessed by delivering the entire
midgut into the operative field. The presence of chylous ascites may indicate chronic
lymphatic obstruction caused by partial midgut volvulus. If volvulus is encountered,
the involved loops of bowel are gently detorsed by counterclockwise rotation until
the mesentery is unfurled. At this time, the bowel is assessed for viability. Reperfusion
154 Langer
and delineating of viable from nonviable bowel may take several minutes. During this
period, the bowel should be covered with a warm, damp laparotomy pad or towel to
help prevent evaporative losses and vasoconstriction. Following this, a Ladd proced-
ure is performed. This operation consists of 4 discreet steps, the goal of which is to
place the bowel into a position of nonrotation, with the small bowel on the right side
of the abdomen and the colon on the left: (1) division of any abnormal bands (Ladd
bands) fixing the bowel to the right upper quadrant retroperitoneal or intra-
abdominal structures; (2) mobilization and rotation of the colon toward the left, taking
care not to injure the colonic mesentery in the process, so that the entire colon sits on
the left side of the abdomen; (3) mobilization and straightening of the duodenum so
that it heads inferiorly and all the small bowel sits on the right side of the abdomen;
(4) broadening of the base of the mesentery by dividing the congenital bands along
the SMA and SMV. If the child has presented with duodenal obstruction, duodenal
patency should be tested by milking gastric contents from the proximal to the distal
duodenum to rule out associated duodenal atresia or web. Most surgeons also
perform an appendectomy, either by excision or using an inversion technique (Fig. 4).
Before closing the abdomen, small bowel viability should be reassessed. Any frankly
necrotic sections should be resected. If the rest of the bowel is completely viable, a
primary anastomosis can be performed, and, if not, stomas should be created. If there
are large sections of bowel in which viability is still unclear, resection should not be
done, and a second-look laparotomy should be planned for 24 to 48 hours later.
More ethically problematic is the situation in which the entire midgut is clearly necrotic,
and resection of the bowel will result in short bowel syndrome. Options include closing
the abdomen without resection and offering palliative care, or performing a massive
resection and creating intestinal failure, with long-term need for total parenteral nutri-
tion. Although historically the prognosis for neonatal intestinal failure was dismal
because of the extremely high incidence of fatal cholestatic liver failure, improvements
in intestinal rehabilitation and small bowel transplantation have resulted in new man-
agement paradigms for children with extreme short bowel and, in selected cases,
massive intestinal resection may be a reasonable option.7
A laparoscopic approach to the Ladd procedure can also be used.8 In most cases,
laparoscopy should only be used for malrotation not associated with midgut volvulus,
because the bowel in patients with volvulus can be friable and subject to perforation.9
In addition, surgery must be done as quickly as possible in patients with volvulus to
maximize the chance of survival, and laparoscopy may waste precious time. The oper-
ation begins with the placement of an umbilical trocar and abdominal insufflation, fol-
lowed by the placement of 2 additional trocars in the right lower quadrant and left
midabdomen (depending on the size of the child). A fourth port may be placed in
the right upper quadrant to assist with retraction. Careful exploration of the abdomen
is then performed and the specific anatomy of the patient delineated. If midgut
volvulus is present, the bowel must be detorsed, which can be difficult, especially if
the bowel is distended or fragile. If this is the case, the operation should be converted
to an open approach. If there is no volvulus, the next step is determination of the length
of the small bowel mesentery; that is, the distance between the DJJ and the cecum. If
this distance is long (in our center this is defined as greater than half the diameter of the
abdomen, although this is an arbitrary threshold that so far is not evidence based), as
is seen in both near-normal rotation and in nonrotation, the patient is not considered to
be at risk for midgut volvulus, and a Ladd procedure is not considered to be neces-
sary. In this scenario, obstructing bands around the duodenum should be identified
and divided (especially if the child is having symptoms that might be caused by partial
duodenal obstruction), any internal hernias should be identified and repaired, and an
Intestinal Rotation Abnormalities 155
Fig. 4. Operative steps of Ladd procedure. (A) Bowel is assessed and, if volvulus is present,
gently detorsed in a counterclockwise direction (arrow). (B) Ladd bands attaching the colon
to the liver, gallbladder, or retroperitoneum are divided sharply or with electrocautery. (C)
Adhesions to the mesentery are divided (arrows) and the mesenteric pedicle widened, al-
lowing the colon to be placed on the left side of the patient and the small bowel with a
straightened duodenum on the right. (D) Final position of the bowel contents at the
completion of the Ladd procedure. An appendectomy has been performed to avoid future
confusion with the presentation of atypical appendicitis in the left abdomen.
156 Langer
SPECIAL CONSIDERATIONS
Asymptomatic Rotation Abnormalities
Although there is general consensus that symptomatic malrotation should be
addressed surgically, the role of prophylactic surgery in children with incidentally diag-
nosed, asymptomatic rotation abnormalities is less clear. Advocates of routine oper-
ative intervention cite reports of midgut volvulus secondary to malrotation throughout
adult life and further argue that a careful history often elicits subtle symptoms of mal-
rotation that may have been dismissed or attributed to other causes. However,
population-based evidence suggests that the incidence of midgut volvulus secondary
to malrotation decreases significantly after infancy and that many patients with rota-
tion abnormalities remain asymptomatic throughout life.
Ultimately, the most important decision in asymptomatic patients is whether there is
a risk of midgut volvulus or not; that is, what is the width of the small bowel mesentery?
Sometimes this can be well seen on contrast imaging, and a reasonable decision can
be made regarding surgical intervention. However, contrast imaging has clearly delin-
eated false-positive and false-negative rates, and laparoscopy may be a safer and
more definitive way of determining the need for a Ladd procedure. If, at the time of lap-
aroscopy, the mesenteric base is found to be wide, the operation can be concluded,
with minimal morbidity. If the mesenteric base is found to be narrow, a Ladd procedure
can be done either laparoscopically or open, at the discretion of the surgeon.
Heterotaxia Syndromes
Patients with HS (defined as any arrangement of organs along the left-right body axis
that is neither situs solitus nor situs inversus) are known to have a high rate of rotation
anomalies, which cover the spectrum from nonrotation to classic malrotation to near-
normal rotation, as well as the more uncommon rotation abnormalities such as reverse
rotation. The coexistence in many cases of congenital heart disease places these chil-
dren at an increased risk of operative intervention, which has resulted in controversy
Intestinal Rotation Abnormalities 157
around the role of generalized screening for rotation abnormalities in patients with het-
erotaxia, and the role of intervention in asymptomatic patients with documented rota-
tion abnormalities.10 Although several centers have found that the morbidity and
mortality associated with a Ladd procedure in patients with HS is not increased
compared with a control population, others have documented a higher anesthetic
and surgical risk in children with HS who have more complex cardiac disease. In addi-
tion, the Ladd procedure is associated with at least a 10% risk of postoperative bowel
obstruction, and overall longer term childhood mortality in patients with HS is 23%,
mainly caused by cardiac disease. In our own study following 152 asymptomatic ne-
onates with HS, only 4 developed gastrointestinal symptoms over a median follow-up
of 18 months (range, 4–216 months), and only 1 of these 4 was found to have malro-
tation on UGI. Of the remaining asymptomatic patients, 43% died of cardiac disease
and none developed intestinal symptoms or complications. The authors have there-
fore adopted a more conservative approach in which asymptomatic patients with
HS are not screened for rotation abnormalities unless they develop symptoms.11
Those with documented rotation abnormalities and either mild symptoms or no symp-
toms are evaluated laparoscopically.
CLINICAL OUTCOMES
Outcomes for children with malrotation and midgut volvulus depend on the degree of
intestinal ischemia and the need for intestinal resection. If intestinal ischemia is exten-
sive and/or the child presents with overwhelming sepsis, death is the usual result. If
massive resection is done and the child survives, outcome depends on the manage-
ment of the resulting intestinal failure; however, many advances have been made in
this area, including the development of intestinal rehabilitation teams and strategies
for the prevention of sepsis, venous thrombosis, and cholestatic liver failure.
Surviving children with midgut volvulus who have an adequate length of small
bowel, and those children without midgut volvulus, have an excellent outcome after
the Ladd procedure. There is a very low rate of recurrence in those who presented
with volvulus. The reported rate of adhesive intestinal obstruction is 10% to 15%,
which may be lower if a laparoscopic approach is used. Some children who presented
with vague symptoms may remain symptomatic, and families should be warned about
that possibility before the Ladd procedure. Some persistently symptomatic children
ultimately are diagnosed with an intestinal motility disorder that may not have been
suspected before the Ladd procedure, and which may be difficult to differentiate
from an adhesive bowel obstruction.
SUMMARY
with HS. In general, the outcomes for children with a rotation abnormality are excel-
lent, unless there has been midgut volvulus with significant intestinal ischemia.
The gold standard for the diagnosis of a rotation abnormality is an upper gastrointestinal
contrast study, specifically looking for the location of the DJJ. Ultrasonography may be useful
as a screening tool.
The 3 potential causes of duodenal obstruction in children with a rotation abnormality are
midgut volvulus, Ladd bands, and an intrinsic duodenal obstruction. Surgeons should look for
all 3 in children undergoing surgery for a rotation abnormality with duodenal obstruction.
The distance between the DJJ and the ileocecal junction represents the length of the base of
the small bowel mesentery, and can be estimated by contrast study or more accurately by
laparoscopy. If this distance is less than half the width of the abdomen, the patient may be at
risk for midgut volvulus and should have a Ladd procedure.
A laparoscopic approach is advantageous for older children without clinical or radiological
evidence of midgut volvulus. Infants and children with midgut volvulus should be approached
by laparotomy.
Controversies
Use of laparoscopy for children with a rotation abnormality
Pros
Ability to determine the length of the small bowel mesentery and potentially avoid the need
for a Ladd procedure if the mesenteric base is long enough to prevent midgut volvulus
Theoretic decrease in risk of adhesive small bowel obstruction
Less pain, faster recovery, better cosmetic result
Cons
Lack of adhesions may increase the risk of recurrent rotation abnormality (assuming that
adhesions are important in preventing recurrence, which is controversial)
Technically challenging in some cases, particularly infants and in children with midgut volvulus
Routine investigation for a rotation abnormality in children with heterotaxia
Pros
Many of these children have rotation abnormalities
Some of these may predispose to midgut volvulus
Cons
Risk of midgut volvulus is extremely low in asymptomatic children
Ladd procedure has a high risk in children with significant cardiac lesions
Long-term risk of adhesive bowel obstruction in children undergoing Ladd procedure
REFERENCES
1. Soffers JH, Hidspoors JP, Mekonen HK, et al. The growth pattern of the human
intestine and its mesentery. BMC Dev Biol 2015;15:31.
2. Malek MM, Burd RS. Surgical treatment of malrotation after infancy: a population
based study. J Pediatr Surg 2005;40:285–9.
Intestinal Rotation Abnormalities 159