Golden rules for diagnosing intestinal malrotation
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Transcript of Golden rules for diagnosing intestinal malrotation
Golden rules for diagnosing intestinal malrotation
Dr/Ahmed Bahnassy
Consultant Radiologist
Riyadh Military Hospital
Malrotation..the ticking bomb
ANOMALIES of bowel rotation and
fixation, or malrotation, are a
common predisposing cause of volvulus
and obstruction in infancy and
Childhood.
Accurate diagnosis is vital to avoid the catastrophic consequences of midgut volvulus
Embryological basis-GIT journey
Malrotation and volvulus
Be alert
First, the initial passage of barium through the duodenum should be observed directly with fluoroscopy to confirm the course of the duodenum and the position of the duodenojejunal junction.
The duodenum often is obscured as the more distal loops of the small bowel fill with barium,
Be quick
Second, the position of the duodenojejunal
junction should be documented with the acquisition of both frontal and true lateral projections.
Be cautious
Third, the stomach should not be overfilled
with contrast.
This will cause downwards displacement of duodenojejunal flexure in lateral view making false positive diagnosis of malrotation.
Too much
Be active
• Fourth, manual palpation may be used during the upper GI study to determine the mobility of the duodenum
Be proactive
• Fifth, other imaging studies should be reviewed.Abnormal relation SMV/SMA in US should raise suspicion .
Be patient
Sixth, if the diagnosis remains in doubt or the upper GI tract findings are equivocal delayed abdominal radiographs should be
acquired to identify the position of the cecum.
The normal position of the duodenojejunal
junction is to the left of the left-sided pedicles of the vertebral body at the level of the duodenal bulb on frontal views and posterior (retroperitoneal) on lateral views.
Katz criteria..historical article very valuable in difficult cases
Measurement and meanings
line
point
Relative importance of signs
9 points Scoring
(a) location of the pylorus to the left of the spine,
(b) Location of the DJJ lower than the superior end plate of L-2,
(c) DJJ to the right of the left pedicle .
(d) cephalocaudal distance from the level of the apex of the duodenal bulb to the DJJ greater than 1.3 cm (adjusted for patient size by dividing the actual measurement
by a correction factor: the sum of the interpediculate distance at T-1 I and
distance between T-11 and T-12 superior
end plates divided by 2),
(e) the vertical portion of the sweep (from the bulb apex to the inferior flexure) longer than the
horizontal portion (from the inferior flexureto the DJJ), (f) length of the horizontal segment less than 2.6 cm
(adjusted for size by using the same correction factor),(g) obstruction of the horizontal segment,(h) jejunum located in the right upperquadrant, and (i) zigzag shape of the jejunum.
Survival guide in controversial cases
With this system, a single positive
finding is consistent with a normal variant
(score 0 or 1), the presence of two positive
findings is indeterminate (score 2), and the
presence of three is indicative of malrotation
(score 3).
Patterns of malrotation in upper GI80% of cases
• The third part of duodeum is retroperitoneal structure.
• This location excludes malrotation 100% as it is the ultimate proof of completion of embryonic journey of fetal GIT .
• Useful sign while doing upper GI ..in either way + or -.
Ultrasound localization of D3
In upper GI..anterior location of duodeum
Swirling sign..controversial significance but still worthy
Swirling SMV
anticlockwise
clockwise
• Abnormal caecal position is not a must in cases of malrotation and colon malrotation can be with normal DJ.
!
• Answer the surgeon question ..is there a midgut volvulus ?
With volvulus..notify urgently
Different appearances
corkscrew
block
Anterior d
Z shape
Malrotation without volvulus
• Beware of pitfalls and normal variants.
Wandering duodenum
Normal location of DJ flexure
Duodenum inversum
The duodenum descends then ascends to the right of the spine,before crossing horizontally to the left (small arrows). The duodenojejunal junction is at a normal location (large arrow)
Duodenal distorsion due to gastric overdistension
Small arrows indicate the course of the duodenum and proximal jejunum. The large arrow indicates the duodenojejunal junction projecting near the midline .After gastric decompression, the duodenojejunal junction was normal