Malrotation

Abhilash

11/09/2013

Introduction

• Malrotation –

• Group of congenital anomalies resulting from aberrant intestinal rotation and fixation.

• Takes place during the first three months of gestation.

• First reported by William Ladd in 1932.

Epidemiology

• Incidence : 1/6000 live births

• Most present < 1 month

• Incidence in general population – 0.2 to 0.5 %

• No sex/race predilection

Embryology

• 1. Herniation

• 2. Return to the abdomen.

• 3. Fixation.

• mutations in the forkhead box transcription factor FOX - familial malrotation

Key points in embryology

• Intestinal rotation starts at 5th week.

• Midgut – SMA

• Rotation takes place around SMA axis

• 270 degree counterclock wise rotation of prearterial and post arterial limb.

• Ladds bands attach to the cecum irrespective of its postion at the end of rotation from right paracolic region.

Nonrotation

• Neither colon or duodenum undergo rotation

• Most common form of malrotation.

• M:F=2:1

• Duodenum not posterior to SMA

• Ligament of Treitz fails to reach its normal position is right upper quadrant.

• Midgut mesentry is narrow and highly mobile.

• May cause

• Duodenal obstruction abnormal peritoneal bands.

• Acute midgut volvulus.

Incomplete rotation

• Counter clock wise rotation of only 180 degrees.

• Caecum in the epigastrium overlying 3rd part of duodenum.

• Most common form of surgically treated malrolation.

REVERSE ROTATION

• Rotates clockwise.

• DJ loop anterior to SMA and transverse colon posterior to SMA.

• Causes

• Compression of colon by SMA -> obstruction.

• Ileocecal volvulus- due to inadequate fixation of right colon.

Stringers classification

• I – Non rotation of colon and duodenum

• IIA – Pure duodenal nonrotation

• IIB- Reversed rotation of duodenum and colon

• IIC – Reversed rotation of duodenum only

• IIIA – Nonrotation of colon

• IIIB- Incomplete fixation of hepatic flexure

• IIIC- Incomplete attachment of cecum and mesocecum

Associated anomalies(seen in 30%-60%)

• Duodenal atresia / stenosis / web

• Congenital diaphragmatic hernia

• Gastroschisis

• Omphalocele

• Choanal atresia

• Polysplenia / asplenia

• Congenital megacolon

How does it present.

• Asymptomatic

• Midgut volvulus

• Mesocolic hernias.

• Duodenal and jejunal obstruction.

• Colonic obstruction.

Clinical features in adults

• Intermittent cramping or persistent aching pain.

• Severe abdominal cramping followed by diarrhea - chronic volvulus.

• Vomiting - bilious /non bilious , variable in duration and frequency.

• Malabsorption - diarrhea, nutritional deficiencies

• Rare - obstructive jaundice, chylous ascites and superior mesenteric vein thrombosis

Plain radiograph

• No pathognomonic signs.

• Right-sided jejunal markings

• Absence colonic shadow in RIF

• Features of complications

- Dilated bowel loops

- Air fluids levels

- Pneumoperitoneum

Ultrasound

• Reversal of the normal anatomic relationship between the SMA and

• “whirlpool sign” - midgut volvulus.

• “bird beak” appearance – duodenal obstruction.

• false-positive rates of up to 21%

Upper GI contrast study

>incomplete duodenal obstruction, usually in the third portion;

>ligament of Treitz not to the left of the midline or at the level of the gastric antrum;

>abnormal position of the proximal jejunal loops to the right of the midline; and

>deformity of the duodenum with a bird's beak, corkscrew,• or coiled• configuration

CT Abdomen

• Anatomic location of small bowel on right and colon on left

• Relationship of the superior mesenteric vessels – “vertically placed or inverted sides”

• Aplasia of the uncinate process

• Features of volvulus / obstruction / gangrene

• Other associated anomalies

Reversal of SMA and SMV Whirlpool sign

Management

• Supportive management.

• Surgical management – Ladds procedure.

Ladd's procedure

Post operative care

• nasogastric decompression

• total parenteral nutrition until return of bowel function.

• Mortality from midgut

• volvulus with severe bowel compromise may exceed 30%.

• Long-term complications

1. adhesive small bowel obstruction (10%),

2. recurrent volvulus,

3. short gut syndrome.

References

• Ladd WE. Congenital obstruction of the duodenum in children. N Engl J Med. 1932;206:277–83.

• Principles and Practice of Pediatric Surgery, 4th Edition. Keith T Oldam.

• Shackelford’s Surgery of the Alimentary tract 7th edition.

• Stringer Pediatric Gastrointestinal Imaging and Intervention, 2nd edition