volvulus

Question 1

def volvulus

Answer 1

twisting of structure around itself. Common sites: sigmoid colon, caecum, more rarely the stomach

in neonates, midgut is more common

sigmoid volvulus occurs when bowel twists on its mesentry - produce severe, rapid, strangulating obstruction and potential ischemia

Question 2

path volvulus

Answer 2

rotation of the segement of bowel = partial or complete closed loop obstruction

with 360degree twist the veins to the bowel are compressed = circulatory impairment if not relieved = gangrene and perforation

in neonatal - malrotation causes the duodenojejunal junction to lie on the right of the midline and the caecum in the upper abdo-men, with resulting narrow midgut mesenteric base and predisposing to vol-vulus.

Question 3

aetiology/RF volvulus

Answer 3

elderly

constipated

comorbid

due to twisting of the large bowel on lax mesentry

Question 4

PATHOPHYSIOLOGY volvulus

Answer 4

→ Closed-loop mechanical bowel obstruction → accumulation of gas and feces within the loop → increased intraluminal pressure → impaired capillary perfusion of bowel → bowel strangulation, ischemia, and gangrene

→ Torsion of the mesenteric vascular pedicle → occlusion/thrombosis of mesenteric vessels → bowel strangulation, ischemia, and gangrene

Question 5

RF volvulus

Answer 5

long mesentery (sometimes due to adhesions or tumour)

• acquired (sigmoid volvulus): chronic constipation , high-fiber diet → chronic overloading of the sigmoid colon → lengthening of the sigmoid colon and its mesentery → increased risk of torsion
• Congenital (cecal volvulus): abnormally mobile cecum → predisposition of the cecum to rotate on its axis (axial torsion) or fold upwards (cecal bascule)

intestinal malrotation: abnormal rotation of the bowel with abnormal fixation of the mesentery to the posterior abdominal wall

megacolon

intestinal bands/adhesions

decreased pelvic space: pregnancy or pelvic mass

previous history of volvulus

mobile caecum

chronic constipation and debility

very high residue diet

tumour

adhesions

chaga’s disease of the colon

parasitic infections

Question 6

RF neonate volvulus

Answer 6

associated with malrotation of Ladd’s bands (peritoneal bands from the caecum to the posterior abdominal wall that cross over the duodenum)

Question 7

epi volvulus

Answer 7

It accounts for 1-2% of colonic obstructions.

sigmoid volvulus is the most common

sigmoid - 70yrs, male more

caecal 40-60yrs, female

intestinal malrotation and midgut volvulus - neonates and infants

more common in Africa and Asia

neonatal - rare, incidence of 5.7/100000 with male predominance

Question 8

cecal volvulus

Answer 8

Axial torsion of the cecum (90% of cases): the cecum rotates on its mesenteric axis → bowel obstruction with vascular compromise

Cecal bascule (10%): the cecum folds upwards onto the ascending colon → bowel obstruction often without vascular compromise

Question 9

sx volvulus

Answer 9

severe colicky abdo pain

previous episodes of abdo pain, decreased after explosive passage of stool/gas

vomiting

abdominal distension/pain tends to be more pronounced with sigmoid volvulus (bowel sounds increased)

reduce appetite

constipation

symptoms of bowel obstruction

if bowel ischemia occurs - tachycardia, hypotension, peritonitis (rebound tenderness), hematochezia or blood on DRE may be present

neonatal presents at 3months with distress due to pain and bile stained vomiting

Question 10

sx cecal volvulus

Answer 10

Acute presentation: features of small bowel obstruction

Insidious onset: recurrent episodes of right lower abdominal pain

Question 11

signs volvulus

Answer 11

if bowel perforation occurs - obliteration of liver dullness on percussion

absent or frequent loud tinkling bowel sounds

blood on DRE

peritonitis (rebound tenderness)

fever, tachycardia, signs of dehydration

signs of bowel obstruction with abdominal distension and tenderness

Question 12

XR volvulus

Answer 12

sigmoid: inverted u loop pf bowel that looks like a coffee bean. It shows the dilated sigmoid colon secondary to volvulus. concavity of bean points to LLQ
cecal: kidney bean sign - A dilated loop of bowel with haustrae, extending from the right lower abdomen towards the left upper abdomen; dilated small bowel loops with multiple air-fluid levels; normal colonic diameter (the colon, being distal to the obstruction, does not dilate). concavity of bean to RLQ

bowel perforation - air under the diaphragm

Question 13

CXR CT volvulus

Answer 13

CXR

if perforation is suspected

CT

whirl sign - pathognomonic for volvulus

see bowel ischemia or perforation if present

Question 14

barium enema volvulus

Answer 14

demonstrates the site of the obstruction

bird’s beak sign (tapering of the dye column at the site of the twist)

In cecal bascule, the end of the barium column is rounded, rather than tapered (tear drop sign).

Sigmoid volvulus: normal-sized rectum with bird’s beak sign at the sigmoid; dye does not enter the sigmoid colon

Cecal volvulus: normal-sized colon with bird’s beak sign at the cecum; dye does not enter the small bowel