GI - Bowel Obstruction: Specific Management

Question 1

Sigmoid Volvulus: pathophysiology

Answer 1

• Most common type of volvulus
• Long mesentery with narrow base (twists on mesenteric base) predisposes to torsion
• usually secondary to chronic constipation
• *leads to closed loop obstruction

Question 2

What are risk factors for developing a volvulus?

Answer 2

• Neuropsych disorders (Rx interferes with intestinal motility - eg TCAs)
• Residents in nursing home/advancing age
• Chronic constipation/laxative use
• M>F
• previous abdo surgery
• Diabetes mellitus

Question 3

Sigmoid Volvulus:

• Presentation
• AXR results

Answer 3

• Males (more common)
• Massive distention with tympanic abdo
• Characteristic inverted U or coffee bean sign

Question 4

Sigmoid Volvulus: Mx (conservative to surgical)

Answer 4

• Often relieved by sigmoidoscopy and flatus tube insertion (monitor for signs of bowel ischaemia after decompression)
• Sigmoig colectomy required if failed decompression or bowel necrosis
• Often recurs: may need elective sigmoidectomy

Question 5

Caecal volvulus: features and Rx

Answer 5

• Associated with congenital malformation where caecum is not fixed in RIF
• only 10% of pts can be detorsed via colonoscopy
• Surgical Rx: right hemi colectomy with ileocolic anastamosis OR caecostomy

Question 6

Gastric volvulus - what is the triad of gastro-esophageal obstruction?

Answer 6

• Vomiting
• Pain
• Failed attempts to pass NGT

Question 7

Gastric volvulus - risk factors

Answer 7

• Congenital

- Acquired: gastric/esophageal surgery or adhesions

Question 8

Gastric volvulus Ix and Mx

Answer 8

• Ix: gastric dilatation and double fluid level on erect films
• Mx: endoscopic manipulation/emergency laparotomy

Question 9

Paralytic ileus: presentation

Answer 9

• Adynamic bowel secondary to absence of normal peristalsis
• Usually SBO
• Reduced/absent bowel sounds
• Mild abdo pain: not colicky

Question 10

Paralytic ileus: causes

Answer 10

• Post op
• peritonitis
• Pancreatitis/localised inflammation
• poisons/drugs (anti aChMs - TCAs)
• Pseudo-obstruction
• Metabolic (HypoK/Na/Mg/Uraemia)
• Mesenteric ischaemia

Question 11

Paralytic ileus: prevention (during surgery)

Answer 11

• Decreased bowel handling
• Laparoscopic approach
• Peritoneal lavage after peritonitis
• Un-starched gloves

Question 12

Paralytic ileus: Mx

Answer 12

• Conservative: drip and suck
• Address underlying causes (drugs/metabolic abnormalities)
• consider need for parenteral nutrition
• exclude mechanical cause

Question 13

Pseudo-Obstruction: presentation

Answer 13

• Clinical signs of mechanical obstruction but not obstructing lesion found
• usually distention only: no colic

Question 14

Pseudo-Obstruction: aetiology

Answer 14

• unknown

- associated with elderly, CVS/Resp disorders, pelvic surgery and trauma

Question 15

Pseudo-Obstruction: Ix and Mx

Answer 15

• Ix: gastrograffin enema (plus usual imaging)

- Mx: neostigmine (anti-cholinesterase) and colonoscopic decompression (80% successful)