MALROTATION OF GUT

PRAVIN NARKHEDE

Intestinal Rotation

• Intestinal malrotation as intestinal nonrotation or incomplete rotation around the superior mesenteric artery (SMA).

• The most common type found in pediatric patients is incomplete rotation predisposing to midgut volvulus, which can result in short-bowel syndrome or even death.

Embryology • Normal rotation takes place around the superior

mesenteric artery (SMA) as the axis. • 2 ends of the alimentary canal, – the proximal duodenojejunal loop and – the distal cecocolic loop, and

• 3 stages of development• Both loops make a total of 270° in rotation during

normal development. • Both loops start in a vertical plane parallel to the

SMA and end in a horizontal plane

• Stage I – 5-10 weeks' gestation– physiologic herniation of the bowel into the base

of the umbilical cord– The duodenojejunal loop begins superior to the

SMA at a 90° position and rotates 180° in a counterclockwise direction. At 180°, the loop is to the anatomical right of the SMA, and by 270°, it is beneath the SMA.

– The cecocolic loop begins beneath the SMA at 270°. It rotates 90° in a counterclockwise manner and ends at the anatomical left of the SMA at a 0° position

– Both loops maintain these positions until the bowel returns to the abdominal cavity.

– Also during this period, the midgut lengthens along the SMA, and, as rotation continues, a very broad pedicle is formed at the base of the mesentery.

– This broad base protects against midgut volvulus.

- SMA is the axis. - DJ loop (red arrow) & cecocolic loop (green arrow)

• Stage II – 10 weeks' gestation, the period when the bowel

returns to the abdominal cavity. – As it returns, the duodenojejunal loop rotates an

additional 90° to end at the anatomical left of the SMA, the 0° position.

– The cecocolic loop turns 180° more as it reenters the abdominal cavity. This turn places it to the anatomical right of the SMA, a 180° position.

• Stage III – 11 weeks' gestation – the descent of the cecum to the right lower

quadrant and fixation of the mesenteries.– Fixation of intestine to posterior body wall

• Ligament of Treitz• Cecum to right iliac fossa• Base of mesentery• Ascending and• Descending colon

Normal Rotation

Types of Malrotation

• Nonrotation– Arrest in development at stage I– DJ loop junction does not lie inferior and to the

left of the SMA, and the cecum does not lie in the right lower quadrant.

– The mesentery forms a narrow base as the gut lengthens on the SMA without rotation, and this narrow base is prone to clockwise twisting leading to midgut volvulus.

Nonrotation

• Incomplete rotation– Stage II arrest , result in duodenal obstruction. – peritoneal bands running from the misplaced cecum

to the mesentery compress the third portion of the duodenum.

– Depending on how much rotation was completed prior to arrest, the mesenteric base may be narrow and midgut volvulus can occur.

– Internal herniations may also occur with incomplete rotation if the duodenojejunal loop does not rotate but the cecocolic loop does rotate.

– This may trap most of the small bowel in the mesentery of the large bowel, creating a right mesocolic (paraduodenal) hernia.

• Incomplete fixation– Potential hernial pouches form when the

mesentery of the right and left colon and the duodenum do not become fixed retroperitoneally.

– If the descending mesocolon between the inferior mesenteric vein and the posterior parietal attachment remains unfixed, the small intestine may push out through the unsupported area as it migrates to the left upper quadrant. This creates a left mesocolic hernia with possible entrapment and strangulation of the bowel.

– If the cecum remains unfixed, volvulus of the terminal ileum, cecum, and proximal ascending colon may occur

• Reverse Rotation– Rare anomaly.– Bowel rotates in

varying degrees in a clockwise direction.

– DJ loop is anterior to SMA & CC loop in retroarterial leading to colonic obstruction.

– Cecum maybe Right or Left sided

Differential Diagnosis

• Bowel Obstruction in the Newborn• Duodenal Atresia• Gastroesophageal Reflux• Intestinal Volvulus• Necrotizing Enterocolitis• Neonatal Sepsis

Clinical Presentation

• Male to Female ratio of 2:1• 40% prsent in 1st week • 50% by age 1 month & 75% by age 1 year. • 25% of patients present after age 1 year and

into late adulthood• varies in patients with intestinal malrotation

according to acute or chronic presentation & according to type of rotational defect

• Midgut Volvulus• Acute– first year of life– primary presenting sign bilious emesis.

• Chronic– due to intermittent or partial twisting that results

in lymphatic and venous obstruction– recurrent abdominal pain and malabsorption

syndrome – recurrent bouts of diarrhea alternating with

constipation, – intolerance of solid food, obstructive jaundice and

gastroesophageal reflux

Midgut Volvulus

• Duodenal Obstruction• Acute – due to compression or kinking of the duodenum by

peritoneal bands (Ladd bands).– forceful vomiting, which may or may not be bile-

stained, depending on location of the obstruction with respect to the entrance of the common bile duct (ampulla of Vater).

• Chronic – infancy to preschool-age– most common symptom is vomiting, which is usually

bilious.– failure to thrive and intermittent abdominal pain

(frequently diagnosed as colic).

Ladd’s band

• Internal Herniation– usually has a chronic picture– recurrent abdominal pain, which may progress

from intermittent to constant.– vomiting as well as constipation at times.– They are often diagnosed with psychosocial

problems.

Diagnosis

• Routine blood examination• Serum electrolytes

Imaging Studies

• Plain abdominal radiography– limited use for defining obstruction because

infants may have a gasless abdomen or almost normal

– duodenal obstruction, if present shows the double-bubble sign

• Upper GI series– Study of choice in patients who are stable– contrast ends abruptly or tapers in a corkscrew

pattern, midgut volvulus or some other form of proximal obstruction may be present

• Diagnostic Findings– Abnormal position of duodenum (Ligament of

Treitz on right)– Duodenal obstruction– Beak appearance of duodenum with volvulus

• Lower GI series (contrast enema)– rule out colonic obstruction and ileal atresia.

However, a normally placed cecum does not unequivocally rule out a malrotation,

– Not very helpful

• Ultrasonography– very sensitive (approximately 100%) in detecting

neonatal malrotation.– Highest sensitivity is achieved when inversion of

the superior mesenteric artery (SMA) and the superior mesenteric vein (SMV) is shown

– diagnostic findings are fixed midline bowel loops and duodenal dilation with distal tapering

– volvulus is highly probable if the SMV is shown to be coiling around the SMA.

– All features are enhanced if water is instilled first by nasogastric (NG) tube.

• CT scan– not well developed for diagnosing malrotation

and midgut volvulus– not recommended as the principal diagnostic tool.

Treatment

• NG tube insertion– to decompress the bowel proximal to any

obstruction that may be present.

• Central venous catheter placement– especially if midgut volvulus is present.for

intravenous nutrition is likely to be necessary

• Medical Care– stabilizing the patient– Correct fluid and electrolyte deficits– Administer broad-spectrum antibiotics prior to

surgery– Corret hypotension with appropriate fluids, blood

products, and vasopressor, dopamine 1st choice because of its possible effects to increase splanchnic blood flow infusion rate of 3 mcg/kg/min intravenously (IV)

– Quick surgical intervention is needed

• Surgical Care• Ladd procedure – Cornerstone of surgical treatment – Detorsion of Midgut Volvulus– Lysis of adhesive bands– Placement of Small bowel in non rotated position

on the right side of abdominal cavity.– Placement of Large bowel on the left side of

abdominal cavity.– Inversion Appendectomy

Ladd’s Procedure

• Midgut volvulus– volvulus usually twists in a clockwise direction,

reduction is accomplished by twisting in a counterclockwise direction

– After the blood supply has been restored by detorsion• Viable bowel – good outcome• Gangrenous bowel – resecton & anastomosis

– Enterostomy is performed when questionable viability is observed at the ends of a gangrenous area that is resected.

– If multiple areas of questionable viability are present, many surgeons choose to leave the areas and perform a second-look operation in 12-24 hours if the patient is not showing clinical recover

• Duodenal obstruction– volvulus is reduced – Identify any extrinsic obstruction to the duodenum– peritoneal bands crossing the duodenum are found,

ligate them with careful attention to protecting the superior mesenteric vessels.

– Extrinsic obstruction may also be due to the cecum, colon, or superior mesenteric artery (SMA) impinging on the duodenum; relief is obtained by placing the cecum with its mesentery in the left upper quadrant and exposing the anterior duodenum through its entire length.

– determine that no intrinsic obstruction exists by passing an NG tube through the duodenum.

• Appendectomy– dissection of the peritoneal bands causes damage

to the appendiceal vessels.– advisable because the normal anatomical

placement of the appendix is disrupted when the cecum is placed on the left side of the abdomen

• Laparoscopy– used to repair malrotation with signs of duodenal

obstruction but no midgut volvulus.– The Ladd procedure, including widening of the

mesenteric base and dissection of peritoneal bands, has been performed successfully and has resulted in shorter hospital stays.

Complications

• Short-bowel syndrome– the most common complication of midgut

volvulus., 18%• Wound Infection• Recurrent volvulus is relatively infrequent but

must be of prime concern in patients presenting with obstructive symptoms

• Postoperative obstruction commonly due to adhesive bands.

Prognosis

• In general, older children do better than infants.

• The presence of midgut volvulus prolongs hospitalization, and prognosis is based on how much bowel is preserved.