Bowel obstruction
By definition is a mechanical or functional obstruction of the intestines, preventing the normal transit of the products of digestion.
Small bowel obstruction Extrinsic lesions –Adhesions 50-70% –Hernia: internal or external 25% –Volvulus 5% –Masses Bowel wall lesions –Neoplasm 5% –Inflammatory –Vascular insufficiency –Intramural hemorrhage –Stricture,atresia Luminal occlusion –Swallowed (bezoar, gallstone, ascaris) –Intussusception –Tumor
Small bowel obstruction Plain film –>3 bowel loops –>3 cm3-5 hr –Air-fluid level –Disparity in size between obstructed loops and contiguous loops beyond site of obstruction. –Little/no gas in colon12-24hr CT –Small bowel dilatation>2.5 cm –Small bowel feces –Transition zone
Small bowel obstruction CT –Circumferential thickening of bowel wall, target sign. –Beaklike narrowing at the site of obstruction –Unusual course of mesenteric vessels –Specific enhancement patterns of the bowel wall –Mesenteric haziness –Engorgement of mesenteric vessels –Mesenteric fluid –Pneumatosis intestinalis –Portomesenteric venous gas
SBO
SBO- post operative
SBO- m/p adhesions
SBO H.
SBO-strangulation a 55-year-old woman presenting with features of intestinal obstruction shows dilated loops of the small bowel associated with thickened edematous valvulae conniventes and a strangulated left inguinal hernia (arrow).
SBO- CLOSED LOOP OBS.
Small bowel obstruction Closed loop obstruction _U or C shaped dilated loops –Increasing intraluminal fluid –“Beak sign” –“Whirl sign”- twisting bowel and mesentery
SBO- closed loop obstruction There is bowel wall thickening and mesenteric edema indicating ischemia
SBO-mass A CT scan of a 36- year-old woman. The axial contrast- enhanced CT scan through the midabdomen shows an extrinsic mass compressing a loop of small bowel.
SBO- intussusception
SBO GSE
Paralytic ileus Electrolytes- hypokalemia Ischemic event Medications (anticholinergic, antidepressants) Neuromuscular disorder (DM, porphyria, lead posisoning, hypothyroidism, amyloidosis, scleroderma, vagotomy etc.) Chest disease (LL pneumonia, pleuritis, MI, pericarditis, CHF) Retroperitoneal disease (hematoma, abscess). Post operative Visceral pain Intraabdominal inflammation
Paralytic ileus Large + small bowel distention Delayed but free passage of contrast material
ileus
post operative
SBO- Meckel’s diverticulum
Colonic obstruction Extrinsic –Mass impression- endometriosis, abscess, tumor – Volvulus – Hernia –adhesions Bowel wall lesions – Tumor (carcinoma) –Inflammtory –Infectious –Wall hematoma Luminal obstruction –Fecal impaction –Intussusception
Colonic obstruction Plain film –Dilated colon +/- small bowel dilatation –Gas fluid levels –75%- the cecum is the most dilated portion. >10 cm high probability for perforation.
Colonic obstruction- hernia
Colonic obstruction- volvulus
Caecal v.
Colonic obstruction- volvulus
Acute colonic pseudoobstruction- Ogilvie syndrome Metabolic imbalance Drugs Retropertoneal trauma Abdominal/ cardiothoracic surgery Age >60y Massively dilated colon (Rt. hemicolon) Normal haustral marking Absence of obstructing lesion.
Colonic pseudoobstruction
Toxic megacolon Acute fulminant colitis Neurogenic loss of motor tone Extensive colonic dilatation Systemic toxicity Profuse bloody diarrhea Mortality- 20% Etiology: UC, CD, IC
Toxic megacolon Colonic ileus with marked dilatation of transverse colon Air fluid levels Loss of normal colonic haustra Pneumatosis coli +/- pneumoperitoneum Irregular mucosal surface
Toxic megacolon
Colonic obstruction- sigmoid carcinoma
Colonic obstruction- Descending colon carcinoma