Large Bowel Obstruction M K Alam Al Maarefa College

ILOs At the end of this presentation students will be able to describe: Pathophysiology, clinical features, diagnostic work up and management of large bowel obstruction. Pathophysiology, clinical features, diagnostic work up and management of large bowel volvulus. Pathophysiology, clinical features, diagnostic work up and management of pseudo-obstruction. Types and indications of different type of colostomies

ANATOMY

ANATOMY General characteristics larger internal diameter Presence of epiploic appendices Presence of taeniae coli Presence of the haustra

PHYSIOLOGY Primary function of the large intestine absorption of water Normal flora manufacture- B complex, K Formation, storage and expulsion of feces

Large bowel obstruction Early identification Prompt surgical intervention Delay- risk of perforation → fecal peritonitis.

MECHANISM OF OBSTRUCTION Mechanical obstruction- neoplasm, volvulus, stricture Functional obstruction- pseudo obstruction (Ogilvie’s syndrome)

PATHOPHYSIOLOGY - Mechanical obstruction Interruption to the flow  bowel dilatation above the obstruction  mucosal edema + impaired venous drainage & arterial blood flow → ischemia ↓ ↑mucosal permeability  bacterial translocation +systemic toxicity + dehydration + electrolyte disturbances. Perforation → fecal peritonitis The process is accelerated in closed loop obstruction

PATHOPHYSIOLOGY Pseudo-obstruction (Ogilvie’s syndrome) Colonic dilatation without mechanical lesion Multiple medical and surgical illness- ↓PSY & ↑SY activity  loss of peristalsis, distension by gas & fluid. Maximum in the caecum Perforation leading to faecal peritonitis (3-15%)

Prevalence- increases with age as does its main causes Aetiology of LBO Prevalence- increases with age as does its main causes Neoplasm (benign or malignant) 60% Stricture (diverticular or ischemic) 20% Volvulus (colonic, sigmoid or caecal) 10% Intussusceptions Adynamic obstruction (Ogilvie’s syndrome)

Aetiology of LBO (contd.) Fecal impaction, foreign body Adhesions Hernia IBD Pediatrics: Hirschsprung’s, meconium ileus, imperforate anus

Etiology of LBO

Neoplasm & Diverticular disease Growth  luminal narrowing  gradual onset of obstruction. Diverticular disease: Muscular hypertrophy of the colonic wall with repeated inflammation & fibrosis  luminal narrowing

Colonic volvulus Twisting of the bowel on its mesentery  ischemia  perforation. 20% of LBO. Sigmoid volvulus: Elderly & frail: long h/ o constipation and laxative use Young - association with high fiber diet. The twist is ante-clockwise Caecal volvulus: Less common Clockwise twist

Intussusception Pediatric- usually with no leading point. Adult- caused by tumor (60-70%) Entero-colic or Colo-colic types

Acute colonic pseudo obstruction (Ogilvie’s syndrome) Functional obstruction. Elderly debilitated patients Medical (infections, Cardiac disease) Trauma (operative, non operative).

Clinical presentation Crampy abdominal pain Constipation Abdominal distention Nausea and Vomiting Symptoms suggestive of peritonitis Internal fistula (passage of air, mucus or feces in the urine)

Assessment of symptoms should attempt to distinguish the following: Acute Vs acute on chronic obstruction Onset, H/o bowel movement, stool caliber, recurrent LLQ pain and weight loss Complete Vs partial obstruction By symptoms and rectal examination

Mechanical Vs functional obstruction (illeus or Ogilvie’s syndrome) In ACPO (acute colonic pseudo obstruction)- symptoms develop over 1-2 days up to 1 week, distention is early sign, fever is a bad sign Intussusception Recurrent, intermittent colicky pain relieved by fetal position with weight loss and fatigability

Physical examination Abdomen: Distension, ? Asymmetrical, tenderness, ↑ BS, mass Inguinal and femoral region Rectum: empty, blood, mass

Laboratory investigation CBC Serum chemistry Serum lactate Coagulation profile Stool for Occult blood

Plain radiograph

AXR- small bowel obstruction

Plain radiograph- sigmoid volvulus

Contrast radiography (Barium enema)

CT- contrast enhanced Can distinguish between partial & complete obstruction Site of obstruction Tumour stage Gastrographine (water soluble contrast) -if perforation suspected.

Carcinoma right colon Intussusception

Management Initial therapy: Specific management: Correction of fluid and electrolytes imbalance Bowel rest NGT ? Preoperative antibiotic Specific management:

Ogilvie’s syndrome (pseudo obstruction) Treatment of the underlying disorder Cessation of drugs slowing colonic motility If no perforation  conservative treatment. Management of the underlying disorder for 24hr. If failed- neostigmine or colonic decompression (success rate 80%) If perforation or failed conservative treatment  surgical intervention (colectomy). High mortality and morbidity.

Sigmoid Volvulus Sigmoidoscopy/colonoscopy: Deflation, flatus tube Surgery- later, during same hospitalization. Failed sigmoidoscopy/ colonoscopy or presented with features of ischemia/ peritonitis: Urgent laparotomy, un-twisting, sigmoid resection, Hartmann’s procedure/ primary anastomosis. Fixation of the sigmoid loop “if viable”. (High recurrence.)

Caecal or transverse colon volvulus Surgery- volvulus reduced, fixation (caecopexy) or right hemicolectomy. Cecum ischemic or gangrenous  right hemicolectomy.

Children: No peritonitis  contrast enema reduction. Intussusception Children: No peritonitis  contrast enema reduction. If failed or with signs of peritonitis  surgery Adult: Surgery  why? Recurrence: 3% after contrast & 1%after surgery.

Colonic obstruction due to neoplasms- management Endoscopic: Dilatation & stenting of obstructed colon. Palliative- high risk patients with unresectable tumor Preparation for surgery: Relieve the acute obstruction. Allow time for resuscitation & bowel preparation Surgery: Right colon  right hemicolectomy Left colon  Hartmann procedure

Diverticular disease Obstruction due to stricture Trial of conservative management If failed- Hartman (emergency) or resection & primary anastomosis

Hartmann's procedure Resection of the rectosigmoid colon, closure of the rectal stump & formation of an end colostomy.

Prognosis Depends on: Patient’s factors Underlying disease Management timing and procedures Development of complications Mortality: Mechanical obstruction: 20%-40% (with perforation) ACPO: 15%-36% (with ischemia, perforation)

Colostomies

Colostomy Colostomy: a surgical procedure where a portion of the large intestine is brought through the abdominal wall to carry stool out of the body. Permanent or temporary. End or loop colostomy

Indications in adults Colorectal carcinoma Large bowel Obstruction Traumatic perineal injury High anal fistulae Protection of distal anastomosis Diverticular disease Ischemia IBD

Indications in children Hirschsprung's disease Meconium ileus Imperforate anus Complex hindgut anomalies Volvulus Trauma

End colostomy Proximal end as colostomy. Damaged /diseased distal bowel is removed/ closed Temporary- allow bowel rest or heal, following tumor resection, traumatic injury or inflammation of the bowel. Permanent- distal colon is resected or unresectable Hartmann procedure involves leaving the distal portion of the colon in place, which is closed to create a Hartmann’s pouch.

Loop colostomy A loop of the bowel is brought through the abdomen to the skin surface. Temporarily supported by a plastic bridge/ rod. A communicating wall remains between the proximal & distal bowel. Created in transverse colon (transverse loop colostomy) or in sigmoid colon (sigmoid loop colostomy) Typically an emergency procedure- intestinal obstruction, perforation. Opened at the time of surgery or a few days later. Two openings through the stoma – the proximal end drains stool, the distal portion drains mucus. Loop colostomies are typically temporary.

Loop colostomy

Double-barrel colostomy Both ends of the bowel are brought out. The proximal stoma (colostomy) , diverts feces The distal stoma- mucous fistula Indications: trauma, tumors, or inflammation Temporary or permanent.

Complications Excessive bleeding Ischemic stoma Surgical wound infection Retraction Prolapse Stenosis Parastomal hernia

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