Midgut Volvulus CT

Case Report  – 7 yrs child presents with chronic abdominal discomfort & pain with increase in severity & vomiting since 3 days. CT scan revealed  3^rd part of duodenum is not seen crossing the midline to left side. SMV is seen to left of SMA. Twisting of collapsed 3^rd & 4^th parts of duodenum & mesenteric vessels is seen around the axis of SMA (whirlpool sign) with mild dilatation of stomach & 1^st/2^nd parts of duodenum. DJ junction seen in right lumbar quadrant, jejual loops in right lumbar quadrant, ileal loops in left lumbar quadrant, medial position of right colon & low/ posterior location of transverse colon. Left colon is normally located & collapsed. Findings suggestive of malrotation of small bowel loops with midgut volvulus.

Discussion by Dr MGK Murthy, Dr Pritam, Dr GA Prasad

Intestinal malrotation is described as abnormal positioning of the bowel loops within the peritoneal cavity in the intrauterine life. It is caused by defective rotation of primitive intestinal loop around the axis of SMA during embryogenesis.

Midgut volvulus is a complication of malrotation in which clockwise twisting of the bowel around the superior mesenteric artery axis occurs because of the narrowed mesenteric attachment. Degree of twisting is variable & determines symptoms. Severe volvulus = 3& ½ turns, can lead to bowel necrosis.

Age at presentation – usually neonate or young infant. Occasionally older child or adult.

Associations  ( in 20%) -

-       Duodenal atresia.

-       Duodenal web.

-       Duodenal stenosis.

-       Annular pancreas.

Acute symptoms in new born (medical emergency) - bilious vomiting (intermittent / post prandial /projectile), abdominal distension, shock.

Subacute obstruction with intermittent symptoms in older child – recurrent attacks of nausea, vomiting, pain abdomen.

X ray – Dilated air filled duodenal bulb or double bubble sign with air – fluid levels in duodenum & stomach.

Barium study – DJ junction located to the right. Spiral course of midgut loops (corkscrew appearance or apple peel or twisted ribbon appearance). Duodenal fold thickening & thumb printing (mucosal edema & hemorrhage). Abnormally high position of cecum.

USG – SMV to left of SMA, clockwise whirlpool sign with twisting of mesenteric vessels.

CT - a swirling of vessels in the mesenteric root may be seen at the site of the volvulus, abnormal relationship between the superior mesenteric artery and vein, an ectopic location of the majority of small bowel loops, and an abnormal position of the ligament of Treitz.

Midgut volvulus if not promptly diagnosed and treated, can lead to death or a lifelong dependence on total parenteral nutrition in survivors so surgical correction is the mainstay of treatment.