Midgut mal and nonrotation refers to failure in counter clockwise rotation of the midgut which results in misplacement of the duodeno–jejunal junction to the right of the midline; in addition the small bowel mesentery has narrow vertical posterior attachment which is prone to volvulus.
Other anatomical abnormalities include peritoneal (Ladd's) bands running from the right colon to the lateral abdominal wall and an extensively mobile ceacum that fails to descend.
Malrotation can present as an acute surgical emergency or with more chronic abdominal symptoms.
Acute presentation is with volvulus of midgut or ileoceacum occurring most frequently in neonate with likelihood decreasing with age.[2
] In most of the reported cases of this presentation, patients present with bilious vomiting in the first month of life because of duodenal obstruction or a volvulus.
The chronic presentation is a diagnostic challenge. In most of the reported cases, the usual symptoms were crampy abdominal pain, nausea, vomiting, bloating. The symptoms may be nonspecific. Hence diagnostic delay is common. In a case series by Dietz et al., the duration of symptoms extended as far as 30 years. Pathophysiology of these chronic symptoms may relate to the compressive effects of peritoneal bands running from ceacum and ascending colon to the right lateral wall.
Diagnosis is made by imaging CT scan. The short mesentery allows the small bowel to twist around the narrowed SMA pedicle to create a distinctive “whirlpool” appearance. This appearance is a diagnostic clue of malrotation. Another diagnostic clue is abnormal orientation of the superior mesenteric artery and vein relationship. The superior mesenteric vein lies abnormally to the left of the artery.
Surgical management of intestinal malrotation was first described by Ladd in 1936 and remains mainstay[4
] of management today. It involves reduction of vovulus if present, division of abnormal peritoneal bands (duodeno colic, dodenojejunal-ileocolic), and placement of the small bowel to the right of the abdomen and ceacum to the left. Appendicectomy is also performed as patients may present with appendicitis.[6
Increasingly laparoscopic Ladd's procedures are being performed and have been shown to be effective where there is no acute volvulus.[7
This minimally invasive approach allows for earlier oral intake and discharge from hospital.