Pediatric Small Bowel Volvulus

Etiology: Small bowel twists around an intra-abdominal mass (Meckel diverticulum, mesenteric cyst, ileal duplication) or adhesion or internal hernia caused by small bowel herniating through mesenteric defect
Imaging AXR: Small bowel obstruction
Imaging US: Whirlpool sign of swirled mesenteric vessels and small bowel obstruction
Imaging CT: Whirlpool sign of swirled mesenteric vessels and small bowel obstruction
Imaging CT of internal hernia: Stretched or engorged mesenteric veins and abnormal position of bowel
Note: Closed loop obstruction occurs when bowel is obstructed at two points and this can be caused by volvulus or adhesions or internal hernia and this often results in bowel ischemia
DDX: Malrotation with midgut volvulus
Complications: Closed loop bowel obstruction leading to bowel ischemia and necrosis
Treatment: Surgical
Clinical:

Radiology Cases of Small Bowel Volvulus

Radiology Cases of Small Bowel Volvulus Due to Mesenteric Cyst

CT of small bowel volvulus around mesenteric cyst — Two contiguous axial images from a CT with contrast of the abdomen show a whirlpool sign of swirling of the mesenteric vessels (above left) around a round low density structure just to the left of the spine (above right). Another axial image from the same exam (below left) shows a normal relationship of the superior mesenteric vein to the right of the superior mesenteric artery although both appear to be shifted to the left. AP image from a subsequent upper GI (below right) shows normal position of the ligament of Treitz in the left upper quadrant.

Radiology Cases of Small Bowel Volvulus Due to Meckel Diverticulum

UGI of false positive malrotation with midgut volvulus — AXR upright (left) shows multiple dilated loops of small bowel with air fluid levels. Sagittal US of the abdomen (above right) shows multiple dilated loops of peristalsing small bowel, however an intussusception was not seen. AP image from an upper GI exam (below right) shows the duodenal-jejunal junction to be low in position and to be to the right of the spine.

CT of Meckel diverticulum causing small bowel volvulus and a closed loop obstruction resulting in small bowel ischemia — Coronal (above left) CT with contrast of the abdomen shows in the center just above the bladder a C-shaped dilated small bowel loop with a thickened wall that is not enhancing. On the sagittal image (above right) the dilated, thickened and nonenhancing small bowel loop is seen anteriorly in the abdomen and superior to the bladder. On the axial image (below) the small bowel loop is in the center of the pelvis.

US of Meckel diverticulum — Transverse US of the abdomen (below) shows a non-peristalsing cystic lesion in the center of the image superiorly. Transverse US (above) shows a dilated loop of small bowel with an air-fluid level within it.

Surgery Cases of Small Bowel Volvulus

Surgery Cases of Small Bowel Volvulus Due to Meckel Diverticulum

Surgical image of Meckel diverticulum — Surgical image shows dilatation of almost the entire small bowel except for the decompressed terminal ileum in the left lower corner of the photograph. At this transition point, a diverticulum is noted on the anti-mesenteric border of the ileum.

Surgical image of Meckel's diverticulum — Surgical image shows shows multiple dilated loops of small bowel in the background with a sharp transition point seen in the center of the image in the terminal ileum where on its anti-mesenteric border a diverticulum is seen with an omphalomesenteric duct remnant coming off it. This remnant had been attached to the under surface of the umbilicus, serving as a fulcrum for a small bowel volvulus, resulting in a small bowel obstruction.

Surgical image of Meckel diverticulum causing closed loop bowel obstruction — Surgical image shows a closed loop small bowel obstruction caused by a small band of tissue (between the forceps) extending from small bowel to a purple in color Meckel diverticulum (center of image) arising from the antimesenteric border of the small bowel.

Surgical image of Meckel diverticulum causing closed loop small bowel obstruction — Surgical image shows a dark and necrotic appearing distal ileum and a dark and necrotic appearing Meckel diverticum on the antimesenteric border of the bowel with a prominent vitelline artery (upper right corner of image) and volvulus of the adjacent intestine around it.

Surgical image of Meckel diverticulum causing closed loop small bowel obstruction — Surgical image shows a dark and necrotic appearing distal ileum (left side of image) with a dark and necrotic Meckel diverticulum along the antimesenteric border of the bowel (upper image) causing an internal hernia and a closed loop small bowel obstruction with the necrotic distal ileum herniating through the band of the vitelline duct.

Gross Pathology Cases of Small Bowel Volvulus

Gross Pathology Cases of Small Bowel Volvulus Due to Meckel Diverticulum

Gross pathology image of Meckel diverticulum — Gross pathological image shows a resected loop of necrotic distal ileum. The necrotic Meckel diverticulum is noted in the upper center of the image, arising from the antimesenteric border of the bowel.