Golden rules for diagnosing intestinal malrotation
Golden rules for diagnosing intestinal malrotation Dr/Ahmed Bahnassy Consultant Radiologist Riyadh Military Hospital
Malrotation..the ticking bombANOMALIES of bowel rotation andfixation, or malrotation, are acommon predisposing cause of volvulusand obstruction in infancy andChildhood.Accurate diagnosis is vital to avoid thecatastrophic consequences of midgutvolvulus
Be alertFirst, the initial passage of barium throughthe duodenum should be observeddirectly with fluoroscopy to confirm thecourse of the duodenum and the positionof the duodenojejunal junction.The duodenum often is obscured as themore distal loops of the small bowel fillwith barium,
Be quickSecond, the position of the duodenojejunaljunction should be documented with theacquisition of both frontal and true lateralprojections.
Be cautiousThird, the stomach should not be overfilledwith contrast.This will cause downwards displacement of duodenojejunal flexure in lateral viewmaking false positive diagnosis ofmalrotation. 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 orthe upper GI tract findings are equivocaldelayed abdominal radiographs should beacquired to identify the position of thececum.
The normal position of the duodenojejunaljunction is to the left of the left-sidedpedicles of the vertebral body at the levelof the duodenal bulb on frontal views andposterior (retroperitoneal) on lateral views.
Katz criteria..historical article very valuable in difficult cases
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 thehorizontal 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 casesWith this system, a single positivefinding is consistent with a normal variant(score 0 or 1), the presence of two positivefindings is indeterminate (score 2), and thepresence of three is indicative of malrotation(score 3).
Patterns of malrotation in upper GI 80% 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 -.
Wandering duodenum Normal location of DJ flexure
Duodenum inversumThe 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 overdistensionSmall arrows indicate the course of the duodenum and proximal jejunum. The largearrow indicates the duodenojejunal junction projecting near the midline .After gastric decompression, the duodenojejunal junction was normal