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Chapter 48
Anomalies of Intestinal Rotation
François I. Luks
Rotational anomalies of the intestinal tract refer to the failure
of the primitive midgut to establish its normal anatomical
relationships and attachments as it develops into duodenum,
small bowel, and proximal colon. The incidence of isolated
malrotation in the general population is estimated at 1 in 500
live births, but it is much more common in a number of
genetic, chromosomal, and congenital disorders. The term
malrotation is most commonly used to describe nonrotation,
whereby the duodenum fails to form its characteristic C-loop
and instead runs in a straight cephalocaudal line into the
proximal jejunum. Other rotational anomalies include incomplete rotation, where the normal rotational process of the
midgut has been interrupted, reverse rotation, and errors of
intestinal fixation, typically of the cecum and the ascending
and descending colon.
Embryology
The final anatomic arrangement of the midgut follows a
complex series of events that starts around the fourth week of
gestation, when the straight intestinal tube rapidly elongates
and the embryo develops left–right differentiation. Midgut
rotation has been artificially divided into three stages, representing the various positions of the distal duodenum and the
cecum as they follow a 270° counter-clockwise path. The
exact understanding of this intricate four-dimensional process is less important than the final anatomic relationships
between the various components of the midgut, the mesentery and the vascular pedicle of the superior mesenteric
artery. The key features of normal intestinal rotation include:
(1) the duodenum describes a C-loop with concavity to the
F.I. Luks (*)
Warren Halpert Medical School of Brown University, Providence,
RI, USA
and
Division of Pediatric Surgery, Hasbro Children’s Hospital,
2, Dudley Street, Suite 180, Providence, RI 02905, USA
e-mail: [email protected]
patient’s left and the third portion of the duodenum (at the
ligament of Treitz) to the left of the midline; (2) the superior
mesenteric artery runs in front of the third portion of the duodenum, which is in a retroperitoneal position; (3) the mesentery is attached posteriorly along a broad line that runs from
the ligament of Treitz in the left upper quadrant to the cecum
in the right lower quadrant, thereby preventing torsion of the
mesentery on its axis (Fig. 48.1), and (4) the colon describes
a frame with the cecum and ascending colon fixed along the
right side of the abdomen and the descending colon fixed
along the left side.
The initial mechanisms of normal intestinal rotation are still
poorly understood, but likely involve the same genes that are
responsible for other aspects of asymmetrical development, the
most important of which is the infolding of the primitive heart
to form a four-chamber structure with clear separation between
systemic and pulmonary circulations. Several disorders of left–
right differentiation, such as the heterotaxia syndromes, are
therefore often associated with some form of anomalous intestinal rotation, abnormal budding of the endodermal appendages (polysplenia or asplenia, biliary anomalies, preduodenal
portal vein), and varying degrees of cardiac anomalies. In
immotile cilia disorders such as Kartagener syndrome, 50% of
patients have situs inversus/ambiguus or anomalous intestinal
rotation. All these disorders may be related to abnormal expression or differential signaling of the Hedgehog genes, transforming growth factor (TGF) b, and tyrosine kinase receptor
pathways, all of which play a crucial role in establishing left–
right asymmetry in the early embryo.
As the intestinal tract rapidly elongates around the fourth
week of gestation, it temporarily leaves the abdominal cavity
through a wide umbilical ring, while it also undergoes its
rotational changes: both the duodenum and the colon rotate
270° counter-clockwise to lie in their final configuration.
The last stage of intestinal rotation is completed as the midgut
returns to the abdominal cavity. Any event that interferes
with this process can result in incomplete rotation or nonrotation of the midgut. Thus, congenital diaphragmatic hernia
and abdominal wall defects are associated with malrotation.
It should be noted that while the visual image of moving and
rotating intestinal loops can be illustrative, the process is
P. Mattei (ed.), Fundamentals of Pediatric Surgery,
DOI 10.1007/978-1-4419-6643-8_48, © Springer Science+Business Media, LLC 2011
373
374
F.I. Luks
Fig. 48.1 Cut-out view of
the mesentery in normal
rotation (left) and non-rotation (right). Normally, the
posterior attachment of the
mesentery stretches from the
ligament of Treitz to the
ileocecal valve (ICV),
preventing torsion of the
mesenteric vessels. In
non-rotation, the posterior
mesenteric attachment
(between duodenum and
ICV) is narrow, placing it at
risk of volvulus around the
superior mesenteric artery
more likely one of differential growth and proliferation of
specific portions of the primitive intestinal tube, as elegantly
demonstrated by Kluth and Lambrecht in their scanning
electron microscopy studies of the fetal rat.
In the absence of normal intestinal rotation, the duodenum
fails to cross the midline and its third portion lies to the
right of the spine. The SMA never crosses the duodenum
and lies within a narrow mesenteric base that connects the
duodenojejunal junction with the cecum (Fig. 48.1). The
cecum is in a left paramedian location and congenital
bands between duodenum and cecum keep the mesenteric
root attached in a single narrow pedicle rather than the
broad base seen in normal rotation. This configuration
places the mesentery at risk for complete volvulus, which
results in vascular cut-off at the root of the SMA and ischemic necrosis of the entire midgut from duodenum to
proximal transverse colon.
Two other features of nonrotation or incomplete
rotation can become clinically significant. The cecum is
normally fixed to the right lateral abdominal wall by
peritoneal folds. These bands (Ladd’s bands) are frequently
present in malrotation and cause varying degrees of duodenal or proximal jejunal obstruction as they cross from the
cecum to the right peritoneal wall. In addition, the anomalous location of the appendix can create diagnostic uncertainty in patients presenting with acute appendicitis and
left-sided abdominal pain.
There are other, less common forms of rotational anomalies. These include reverse rotation, whereby the duodenum
comes to lie in front of the colon, and fixation anomalies of
the colon. When either the ascending or the descending colon
fail to adhere to the posterior abdominal wall, small bowel
loops can herniate through these mesocolic gaps and cause
an intestinal obstruction. These conditions are not only rare,
but very difficult to accurately diagnose preoperatively.
Diagnosis
The majority of children with malrotation present in infancy,
but since abnormal intestinal rotation is often asymptomatic,
its true incidence is unknown. The most dramatic presentation of malrotation is midgut volvulus. This must be
suspected in any infant who presents with bilious vomiting,
and prompt diagnosis is important to avoid ischemic loss of
intestine. Midgut volvulus and other intestinal catastrophes
are easily differentiated from hypertrophic pyloric stenosis,
where vomiting is non-bilious and occurs in an otherwise
well and hungry child. Bilious vomiting is seen in half of the
infants and one third of those older than 1 month who present
with malrotation or midgut volvulus. Bilious vomiting is not
pathognomonic for malrotation and is seen with other forms
of intestinal obstruction, such as duodenal atresia, annular
pancreas, small bowel atresia, meconium ileus, and
Hirschsprung disease. While these conditions are all surgical,
they do not require immediate surgical exploration. Initial
treatment consists of bowel rest, intravenous hydration, and
nasogastric decompression. Midgut volvulus, on the other
hand, demands rapid operative correction, as it is associated
with extensive intestinal ischemia. Initially, the infant with
midgut volvulus has a scaphoid abdomen, since the point of
48 Anomalies of Intestinal Rotation
obstruction is so proximal. However, gastric distention can
obscure this clinical finding. As venous and lymphatic
congestion progress toward ischemia, the intestinal loops
become thickened and fluid-filled, and abdominal distention
develops. By then, the child appears sick, with significant
hypovolemia from third-space fluid losses and vomiting.
Sloughing of intestinal mucosa can occur, leading to bloody
stools. Clinical features include tachycardia, oligo- or anuria,
poor capillary refill, metabolic acidosis and, ultimately,
vascular collapse.
Imaging plays a central role in the diagnosis of malrotation. A plain abdominal radiograph is non-specific, but may
sometimes suggest the diagnosis. In the presence of tight
Ladd’s bands, duodenal obstruction may be seen as a
“double bubble,” similar to that seen in patients with duodenal atresia. Unlike the usual situation with duodenal atresia.,
there is usually some distal intestinal gas, unless a complete
midgut volvulus is present. In that case, the abdomen is gasless, save for the gastric and duodenal bubbles. In advanced
volvulus, intestinal ischemia may result in breaches in the
mucosal barrier, and the clinical and radiographic signs may
be indistinguishable from those of necrotizing enterocolitis.
These include intestinal pneumatosis and portal vein gas. It
is important to realize that more than one cause of proximal
intestinal obstruction may be present in the same infant: duodenal atresia and duodenal web can be associated with malrotation, as can jejunal atresia.
If the child’s condition permits, malrotation is most reliably
diagnosed with an upper gastrointestinal contrast study. As
contrast leaves the stomach, the duodenum and proximal jej
unal loops opacify to the right of the midline (Fig. 48.2).
Normal rotation of the midgut includes a duodenal C-loop that
crosses the midline and the ligament of Treitz (duodenojejunal
Fig. 48.2 Upper gastrointestinal contrast study (UGI) in an infant with
malrotation: the duodenum does not cross the midline (enhanced vertebral bodies) and the duodenojejunal junction lies to the right of the spine
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junction) that is located to the left of the spine and at least as
high as the pylorus. These are important landmarks, because
even a nonrotated duodenum may be tortuous (particularly if
Ladd’s bands partially occlude the duodenal outlet). This may
give the impression of a C-loop, but an incomplete one,
whereby the duodenojejunal junction does not quite reach the
level of the gastric outlet. Other features of malrotation on
UGI include right-sided position of the majority of small
bowel loops and absence of a typical colonic frame. Instead,
ascending and transverse colon are all located to the left of the
spine (Fig. 48.3). A contrast enema may show the colonic
anatomy better, but this is a less reliable test – even a partially
or completely rotated colon does not rule out malrotation or,
more importantly, a narrow-based mesenteric attachment and
its associated risk of volvulus.
In recent years, ultrasound has been increasingly accurate
in detecting abnormal rotation. If the duodenum is clearly
seen, it can be followed as it is supposed to cross the spine.
The relationship of the superior mesenteric vessels is the
most typical ultrasonographic feature of malrotation.
Normally, the SMA is posterior and to the left of the vein. In
malrotation, the SMA lies to the right of the vein. In midgut
volvulus, the further torsion of the vessels can be clearly seen
as a swirl, or whirlpool pattern, on Doppler ultrasound
(Fig. 48.4). The duodenal obstruction may be clearly visible
Fig. 48.3 UGI in an older child with malrotation. Note duodenum and
small bowel on the right and colon on the left
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F.I. Luks
Fig. 48.4 Ultrasonographic signs of midgut volvulus. Top: “swirling” pattern of the superior mesenteric vessels due to volvulus of the mesentery.
Bottom: beak-like obstruction of the duodenum (arrow)
and the torsion may give it a bird’s beak appearance
(Fig. 48.4). Other ultrasonographic signs of advanced midgut
volvulus include free peritoneal fluid, intestinal wall edema,
pneumatosis, and portal vein gas. While often accurate,
ultrasonography is not as reliable as UGI in the diagnosis of
malrotation. The right-sided course of the duodenum and the
mesenteric vessel inversion may be missed, and false-positive results may be seen with any process that pushes the root
of the mesentery to the right, such as acute gastric distention,
splenomegaly or a splenic hematoma. The whirlpool sign
and duodenal obstruction can also be seen on abdominal CT,
however CT is not the diagnostic procedure of choice for
either malrotation or midgut volvulus.
While it is the diagnostic cornerstone of malrotation, one
should forgo the UGI study if midgut volvulus is suspected,
particularly in the very young infant. Any delay in surgical
intervention can result in irreversible ischemic damage to the
entire midgut, which in turn may lead to short bowel syndrome
or death. The combination of bilious emesis, a scaphoid
abdomen (after gastric decompression), and shock require
prompt exploration. If the presentation is less dramatic, it may
be reasonable to obtain an UGI, as long as surgical delay is
kept to a minimum. The typical appearance of midgut volvulus
on UGI is a corkscrew or apple-peel appearance of the first
jejunal loops, best seen in a lateral view (Fig. 48.5).
The management of asymptomatic malrotation is the subject of some debate. In the past, many have argued that malrotation is never asymptomatic, since its discovery follows an
imaging study that was obtained for a reason. However, the
symptoms ascribed to malrotation are often vague and nonspecific, including gastroesophageal reflux, chronic emesis,
colicky abdominal pain, malabsorption, chronic diarrhea, or
failure to thrive. Moreover, the presence of certain pathologies
(heterotaxia syndromes) will often lead to a search for
Fig. 48.5 Midgut volvulus (lateral view of an UGI): note corkscrew
appearance of the duodenum and proximal jejunum
associated malrotation – and the increased use of medical
imaging has led to the incidental finding of malrotation in
patients who truly have minimal to no symptoms. The diagnostic criteria for malrotation in older or asymptomatic patients
are the same as in infants. Malabsorption and failure to thrive
may be a result of chronic or intermittent volvulus and lymphatic congestion; vomiting and reflux symptoms may be secondary to partial duodenal obstruction by Ladd’s bands.
48 Anomalies of Intestinal Rotation
Treatment
Midgut volvulus is a surgical emergency. Aggressive intravenous hydration is important to counteract the hypovolemia
due to vomiting and third spacing, but this should not delay
intervention. Antibiotics are administered prophylactically.
A laparotomy is performed through a right transverse incision above the level of the umbilicus. Viscera are gently
exteriorized and examined. Because of the volvulus, the
colon (which now lies posteriorly) is obscured by the small
bowel loops. While maintaining the intestinal loops moist
and warm, the volvulus is untwisted by turning the intestinal
mass in a counter-clockwise fashion. The torsion may be
more than 360°, and the intestinal mass must be gently and
methodically untwisted until the colon comes into view. This
should release vascular constriction and allow the ischemia
to improve. In reality, a midgut volvulus is often confusing at
first and care must be taken not to cause additional bowel
damage during detorsion. In some patients, further confusion
may be caused by the presence of situs ambiguus or situs
inversus, whereby the stomach may be on the right and the
liver midline or on the left. In these cases, the duodenum
may be on the left and the colon on the right.
Once the intestinal torsion is corrected, viability of the
loops is assessed. A period of observation, during which tension on the mesenteric root is alleviated and the viscera are
kept warm, may allow some return of perfusion. If necessary,
a hand-held Doppler probe or fluorescein may be used to
assess vascular status. Only if bowel loops are frankly
necrotic should they be resected – in some cases, it may be
better to preserve borderline viable intestine and perform a
second-look operation in 12–24 h. Overly aggressive resection can result in short bowel syndrome.
After the volvulus has been corrected, the malrotation itself
needs to be addressed. It is also important to confirm the patency of the intestinal tract, particularly in very young infants:
a newborn who presents acutely with midgut volvulus may
also have a duodenal web. This is best ruled out by passing the
nasogastric tube through the duodenum. As the duodenum is
straight, this is easier than with normal rotation.
Surgical correction of malrotation without midgut volvulus
is not an emergency, and may even be unnecessary in some
cases. The main purpose of intervention is to prevent future
midgut volvulus. This implies that the anatomic condition of
the patient predisposes to torsion. While most patients with
malrotation have a very narrow mesenteric pedicle caused by
the close proximity of the duodenum and the ascending
colon, the mesenteric attachment in some patients may be
wide enough so as to be essentially normal. In congenital
diaphragmatic hernia, for example, the intrathoracic migration of small and large intestinal loops allows the posterior
mesenteric attachment to stretch sufficiently to prevent
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future volvulus. The same probably holds true for abdominal
wall defects as well, although cases of midgut volvulus have
been described in these patients. It has been speculated that
the presence of intra-abdominal adhesions (particularly in
gastroschisis) may limit the risk of volvulus, but objective
evidence is lacking. Some surgeons will contemplate a Ladd
procedure during laparotomy for the repair of congenital diaphragmatic hernia if the patient’s condition warrants additional operative time. In all other patients with malrotation,
surgical exploration should be considered.
The classic surgical treatment of malrotation is the Ladd
procedure. Its goals are to relieve any duodenal or jejunal
obstruction and decrease the risk of future midgut volvulus by
widening the mesenteric base. The viscera are carefully
examined, and any bands crossing anteriorly to the duodenojejunal junction are divided (Fig. 48.6). These Ladd’s bands
are avascular, but care must be taken not to damage the underlying mesentery. The root of the mesentery is then exposed,
and the avascular connections between the duodenum and the
ascending colon are carefully dissected with Metzenbaum
scissors. Cautery should be kept to a minimum as mesenteric
injury is a real risk (particularly at the level of the SMA takeoff). The duodenum is then gently teased toward the patient’s
right side of the abdomen, while the cecum and ascending
colon are pushed to the left. This fully exposes the superior
Fig. 48.6 Laparoscopic take-down of Ladd’s bands between cecum and
right lateral abdominal wall (from Lessin MS and Luks FI. Laparoscopic
appendectomy and duodenocolonic dissociation (LADD) procedure
for malrotation. Pediatr Surg Int 1998, Springer. Used by permission)
378
F.I. Luks
asymptomatic patient. Placement of the trocars is straightforward: a 5-mm telescope is introduced through the umbilicus.
Instrument cannulas may be placed in the inguinal regions,
which is cosmetically superior. Because the area of interest
lies in the mid-abdomen, it is not easy to establish a classic
diamond-shaped configuration between telescope, instruments
and target. This lack of adequate triangulation and the short
distance between telescope and target introduce a degree of
difficulty to the laparoscopic procedure. Performing the operation with only two instruments may be challenging as well,
since sharp division of the congenital bands requires adequate
tension between duodenum and colon. If necessary, a third
instrument port should be placed. The appendix lies in a periumbilical location and can be easily exteriorized through the
trocar incision for “open” removal at the end of the laparoscopic procedure.
Postoperative Care
Fig. 48.7 Laparoscopic division of duodenocolonic bands to expose
the root of the superior mesenteric artery and widen the posterior
attachment of the mesentery (from Lessin MS and Luks FI.
Laparoscopic appendectomy and duodenocolonic dissociation (LADD)
procedure for malrotation. Pediatr Surg Int 1998, Springer. Used by
permission)
mesenteric vessels and their proximal branches (Fig. 48.7).
The separation of duodeno-colic bands is all that is needed to
widen the mesenteric base: duodenal fixation and cecopexy in
their respective location is unnecessary. Again, in some
patients the base of the mesentery is already wide enough.
If the root of the SMA is clearly splayed between the duodenum and the cecum, no further dissection is required.
Appendectomy completes the Ladd procedure as the appendix
lies in an abnormal location, making diagnosis of acute
appendicitis difficult. Some surgeons prefer to perform an
inversion appendectomy, citing a lower risk of infection, since
the intestinal tract is not opened: the mesoappendix is divided,
and the appendix is inverted into the colon. An absorbable tie
is used to ligate the appendix at its base. Now devascularized,
the appendix will auto-amputate within days and be eliminated in the stool. Of course, classic appendectomy is
simpler, fast, and actually very safe.
All the steps of the Ladd procedure, except detorsion of a
midgut volvulus, can be safely performed laparoscopically as
well (Figs. 48.6 and 48.7). An increasing number of surgeons
are now choosing this approach, particularly in the older,
The postoperative course primarily depends on the intraoperative findings. In cases with volvulus and significant
intestinal ischemia, a prolonged ileus is typically seen. If
bowel resection was performed, parenteral nutrition might
be required and the chronic treatment of short bowel syndrome may be difficult. If the operation was performed
electively for malrotation alone, prompt recovery can be
anticipated.
The long-term results of Ladd’s procedure are believed to
be excellent. However, postoperative small bowel obstruction occurs in up to 14% of patients, similar to the cumulative risk of small bowel obstruction after laparotomy for
other indications. Moreover, recurrent midgut volvulus has
been described. Its true incidence is not known but probably
occurs in less than 2% of patients. The laparoscopic approach
is too new to provide reliable recurrence rates, but the minimally invasive approach appears to be at least as efficient as
the classic operation. While operative treatment of midgut
volvulus is very effective, it is important to note that chronic
symptoms believed to be associated with malrotation (malabsorption, failure to thrive, vague abdominal complaints)
are less often corrected. Thus, patients and parents must be
warned preoperatively that the operation is mainly aimed at
preventing future midgut volvulus, and that some or all
symptoms may still be present postoperatively.
48 Anomalies of Intestinal Rotation
379
Summary Points
• Bilious vomiting in the newborn is a surgical emergency and suggests intestinal obstruction or midgut volvulus until
proven otherwise.
• If the infant’s condition allows it, a diagnostic upper gastrointestinal series (UGI) may be obtained, but one should
be ready to perform a rapid surgical exploration without imaging.
• Initially, infants with midgut volvulus have a scaphoid abdomen (if the stomach is decompressed).
• Delay in recognition and treatment of midgut volvulus may lead to necrosis of the entire small bowel and part of the
colon.
• Malrotation carries the risk of midgut volvulus at any age – therefore, surgical exploration and a Ladd procedure is
recommended even in the older and asymptomatic patient.
• The main goals of the Ladd procedure are to widen the basis of the mesentery to avoid torsion of the mesenteric
vessels, relief of duodenal obstruction by congenital bands and appendectomy, to avoid future confusion if appendicitis were to develop.
Editor’s Comment
Many people confuse the terms malrotation and volvulus; they
are not interchangeable. Malrotation describes a specific
anatomy that is in and of itself harmless and usually asymptomatic; however, patients with malrotation are at risk for
midgut volvulus, which is potentially catastrophic. In addition
to signifying that the duodenum does not pass behind the SMA,
malrotation also implies that the cecum and jejunum are adjacent to each other and that the entire midgut is based on a
narrow mesenteric pedicle. Nonrotation also indicates that the
duodenum does not pass behind the SMA, but it suggests that
the mesentery is sufficiently broad that the risk of volvulus is
minimal – it is the anatomic configuration that remains after a
properly performed Ladd procedure and occurs naturally in
most patients with congenital diaphragmatic hernia and other
anomalies that associated with rotational abnormalities.
Infants and children with bilious emesis (and no prior
abdominal surgical history) should be presumed to have malrotation with volvulus until proven otherwise. If they are septic or have peritonitis, they should be prepared for immediate
laparotomy. Time is of the essence. If the patient is stable, an
upper GI contrast study should be performed urgently – it
cannot wait until morning! If the findings are consistent with
volvulus, the patient goes to the OR immediately. If there is
malrotation without volvulus, most pediatric surgeons make
plans to operate within 24 h but this can wait until the light
of day. It is important to note that the picture of a wellappearing child and a totally benign abdomen (even if laboratory values and radiographs are within normal limits) does
not rule out the possibility of volvulus with ischemic bowel.
The Ladd procedure can be performed laparoscopically or
open. Most useful when the procedure is being performed
non-emergently, the laparoscopic approach is often quite
difficult and there is a significant rate of conversion to open
even for experienced laparoscopists. Regardless of the
approach, the steps are the same: (1) detorse the bowel in a
counter-clockwise direction (“turn back the hands of time”):
if bowel is frankly necrotic it should be excised, which places
the child at risk for short gut syndrome and intestinal failure,
but if the bowel is of questionable viability, a second-look
operation should be planned for 48–72 h; (2) divide Ladd’s
bands; (3) straighten the duodenum (lyse all adhesions and
undo its typical accordion configuration); (4) broaden the
mesentery – separate the colon and duodenum, open the anterior mesenteric peritoneum, and fan out the vessels of the
mesentery; (5) remove the appendix; (6) establish a nonrotation configuration: place the small bowel on the right side of
the abdomen with the duodenum along the right lateral side
wall, and place the colon on the left side with the cecum in the
left lower quadrant. Cecopexy and duodenal fixation sutures
are unnecessary and create sites around which a volvulus
could occur. When it comes the Ladd procedure, novices
always place undue importance on the lysis of the Ladd bands;
but the most important steps are the broadening of the mesentery, which is what prevents volvulus, and the straightening of
the duodenum, which relieves many of the GI symptoms
patients with malrotation have (emesis, reflux, failure to
thrive). Turbid fluid at operation is almost always chylous
ascites due to lymphatic congestion from partial volvulus and
not evidence of bowel perforation. Postoperatively, many
patients have a prolonged ileus. Some will have protracted
symptoms of duodenal dysmotility or pseudo-obstruction.
There are many variants of malrotation, including partial
rotation, and right and left paraduodenal hernia. All are
treated by trying to establish the nonrotation configuration –
the steps of the Ladd procedure are modified as necessary but
the final anatomy should be the same. The exception is
reverse rotation, which often requires that a portion of the
bowel be divided to relieve entrapment. The rotational
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F.I. Luks
a­ nomalies displayed by patients with heterotaxy are also
often quite challenging to deal with. The goal in these cases
is to do whatever you have to do to leave the patient with a
mesentery that is as broad as possible and therefore unlikely
to volvulize.
The upper GI is the gold standard for the diagnosis of
malrotation but in clinical practice is frustratingly imprecise.
To avoid missing a single case of malrotation, pediatric radiologists adhere to very strict criteria to define normal. Any
variation, no matter how clinically insignificant, will be read
out as the dreaded “cannot rule out malrotation.” Exploratory
surgery has historically been the only way to decide if the
intestine was truly malrotated; however, newer imaging
modalities (US, MR) are becoming increasingly useful ways
to confirm the retroperitoneal sweep of the duodenum and
the absence of a narrow root of the mesentery. The ligament
of Treitz can also be displaced by gastric or colonic distension and simply repeating the upper GI after a few weeks
might yield a different result. Because 15% of patients with
duodenal malrotation have normal colonic anatomy, contrast
enema is not an accurate test for malrotation. Finally, there
are some children who have an abnormally low ligament of
Treitz. If the duodenum passes behind the SMA and the mesentery is sufficiently broad, these children are at minimal
risk of volvulus and can be safely observed.
Differential Diagnosis
•
•
•
•
•
•
Pyloric stenosis
Duodenal atresia
Annular pancreas
Small bowel atresia
Meconium ileus
Hirschsprung disease
□□
□□
□□
□□
□□
Avoid delays
Intravenous hydration
Prophylactic antibiotics
Type & screen
Informed consent
Technical Points
• Right upper quadrant transverse incision
• Careful exteriorization and examination of the
bowel
• Detorsion of the midgut volvulus in a counterclockwise fashion
• Assess and reassess viability of the bowel
• If bowel resection is unavoidable, limit its extent
– if necessary, re-explore after 12–24 h
• Divide Ladd’s bands (crossing duodenum), if present
• Widen mesenteric base by dividing avascular duodenocolonic bands
• Fully expose root of superior mesenteric artery and
its first branches
• Adequate peri- and postoperative hydration to
reverse third-spacing and fluid losses
Suggested Reading
Diagnostic Studies
−− Plain radiograph
−− Upper gastrointestinal (UGI)
(­diagnostic test of choice)
−− Contrast enema
−− Ultrasonography
Preoperative Preparation
contrast
series
Parental Preparation
−− Possible extensive bowel necrosis, bowel resection
−− Possible short bowel syndrome
−− Possible stoma
Ladd WE. Congenital obstruction of the duodenum in children. N Engl
J Med. 1932;206:277–83.
Kluth D, Kaestner M, Tibboel D, Lambrecht W. Rotation of the gut:
fact or fantasy? J Pediatr Surg. 1995;30:448–53.
van den Brink GR. Hedgehog signaling in development and homeostasis
of the gastrointestinal tract. Physiol Rev Surg Int. 2007;87:
1343–75.
Seashore JH, Touloukian RJ. Midgut volvulus: an ever-present threat.
Arch Pediatr Adolesc Med. 1994;148:43–6.
Patino MO, Munden MM. Utility of the sonographic whirlpool sign in
diagnosing midgut volvulus in patients with atypical clinical presentations. J Ultrasound Med. 2004;23:397–401.
Spigland N, Brandt ML, Yazbeck S. Malrotation presenting beyond the
neonatal period. J Pediatr Surg. 1990;25:1139–42.
Lessin MS, Luks FI. Laparoscopic appendectomy and duodenocolonic
dissociation (LADD) procedure for malrotation. Pediatr Surg Int.
1998;13:184–5.
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