Transcript Bowel Obstruction

Bowel Obstruction
Alia Tuqan, M.D.
Goals and Objectives
• Understand the pathophysiology of bowel
obstruction
• Diagnosis of bowel obstruction
• Treatment options for bowel obstruction
▫ Medical and surgical options
Introduction
• Blockage at some point in the gastrointestinal tract preventing the
passage of food and feces
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Partial or complete
Mechanical and/or functional
Benign or malignant
Single or multiple
• Common with certain types of cancers
▫ Colorectal
▫ Ovarian
▫ Metastases from other sites
• Other causes
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Surgical adhesions
Post-radiation fibrosis
Fecal impaction
Inflammatory bowel disease
Introduction
• Morbidity is high and survival is poor in
malignant bowel obstruction (MBO)
▫ Chakraborty et al., 2011
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35 hospitalized patients were included
58% were re-admitted
Median survival was 80 days
17% were alive at 1 year
Pathophysiology
• Bowel obstruction  gut hypoxia and bacterial
overgrowth  gas production and bowel
distension  increased production of vasoactive peptides and splanchnic vasodilation 
increased production and pooling of secretions
 nausea and vomiting and further gas
production and bowel distension  increased
gut peristalsis  abdominal pain and increased
gas, secretions and distension
• A vicious cycle that feeds on itself
Diagnosis
• Based on clinical presentation, exam and imaging
• Patients often present with abdominal pain, nausea,
vomiting and inability to tolerate liquids and solids
• Physical exam reveals high-pitched, hypoactive to
no bowel sounds and a tender abdomen
• Abdominal X-rays show air-fluid levels
• Abdominal and pelvic CT-scans show a variety of
findings:
▫ An intraluminal mass at the point of obstruction
▫ Peritoneal carcinomatosis diffusely lining the bowel
and causing obstruction
Medical Management
• When possible, conservative measures are tried first
• Mechanical decompression with a nasogastric tube
(NGT)
• Anti-cholinergic agents (e.g., scopolamine or
glycopyrrolate) to reduce secretions
• Pro-motility agents (e.g., metoclopramide)
• Steroids (e.g., dexamethasone) to reduce
inflammation and tumor burden
• Manual dis-impaction and bowel regimens to treat
fecal impaction
• Avoidance of constipating medications (e.g., opioids,
tricyclic antidepressants and iron supplements)
Medical Management
• Methylnaltrexone
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For opioid-induced constipation
Works as mu opioid antagonist
0.15mcg/kq SQ or 5-12mg SQ x 1
Max dose: 12mg
Renally-dosed; if GFR < 30, reduce dose by 50%
May repeat after 48hrs
Contraindicated in complete bowel obstructions
Medical Management
• Octreotide
▫ Synthetic somatostatin analog
▫ Decreases secretions, splanchnic blood flow and
peristalsis
▫ Provides symptomatic relief
▫ Dosing:
 Start 50-100mcg q8hrs or 100-200mcg 2-4 times per day
 If this is not effective, a continuous infusion starting at
10-20mcg/hr and at a rate no more than 1200mcg per
day
▫ PO, PR, SQ and IV
▫ Can be efficacious when used in combination with
other medications
Interventions:
• Venting percutaneous endoscopic gastric (PEG)
tube
▫ Typically reserved for patients with poorer
functional status and limited life expectancy when
medications are ineffective
Interventions
• Stenting
▫ Typically reserved for patients with better functional
status, life expectancy of weeks to months, and a single
obstruction
▫ Covered versus uncovered stents
 Risks: stent failure, biliary obstruction, bowel perforation
 Tumor regrowth tends to be more common with
uncovered stents
 Stent migration tends to be more common with covered
stents
 Fernandez-Esparrach et al, 2011 concluded that surgery
over stenting should be considered in patients with good
functional status because of stenting complications
Surgery
• Typically reserved for patients with better
functional status and life expectancy of months
• Involves bypassing or resecting the lesion
Surgery
• Diverting stoma (DS)
▫ E.g., ileostomy or colostomy
▫ Least complex surgery
▫ Has lower complication rates in comparison to
other surgeries
▫ Better for patients with high-tumor burden and
multiple areas of obstruction
▫ Good for distal obstructions in the small or large
bowel
Surgery
• Internal bypass (IB)
▫ More complex of a surgery than DS, less complex
than PR
▫ Better for proximal obstructions in the small
bowel
Surgery
• Palliative resection (PR)
▫ Most complex surgery
▫ Carries the highest complication and survival rate
▫ Good for patients with low tumor burden, isolated
obstruction, and good functional status
Surgery
Table: Surgical Outcomes in Bowel Obstruction
Type of
Surgery
Success (%)
Morbidity
(%)
Mortality
(%)
Survival
(months)
DS
80
40
10
5.3
IB
78
33
0
6.5
PR
63
63
16
8.4
N=43
Englert et al., 2012
Sources
• Anita Chakraborty, Debbie Selby, Kate Gardiner, Jeff Myers, Veronika
Moravan, Frances Wright. Malignant Bowel Obstruction: Natural History
of a Heterogeneous Patient Population Followed Prospectively Over Two
Years. Journal of Pain and Symptom Management. 2011; 41(2): 412-420.
• Zachary P. Englert, Michael A. White, Timothy L Fitzgerald, Anusha
Vadlamudi, Gus Zervoudakis, and Emmanuel E. Zervos. Surgical
Management of Malignant Bowel Obstruction: At What Price Palliative?
American Surgeon. 2012; 78: 647-652.
• Gloria Fernandez-Esparrach, J.M. Bordas, M.D. Giraldez, A. Gines, M.
Pellise, O. Sendino, G. Martinez-Palli, A. Castells, and J. Llach. Severe
Complications Limit Long-Term Clinical Success of Self-Expanding Metal
Stents in Patients With Obstructive Colorectal Cancer. American Journal of
Gastroenterology. 2010; 105: 1087-1093.
• Robert S. Krause. #119 Invasive Treatment Options for Malignant Bowel
Obstruction. Fast Facts and Concepts. End of Life/Palliative Education
Resource Center, Medical College of Wisconsin.
Sources
• John Manfredonia. Urgent Medical Conditions: Spinal Cord
Compression, Hypercalcemia, Seizures, Bowel Obstruction.
AAHPM Intensive Board Review Course DVD. 2012.
• Gola Tradounsky. Palliation of gastrointestinal obstruction.
Canadian Family Physician. 2012; 58(6): 648-652.
• Rodney O. Tucker and Ashley C. Nichols. U4: Managing Non-Pain
Symptoms. American Academy of Hospice and Palliative Medicine.
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• Charles von Gunten and J Cameron Muir. #45 Medical
Management of Bowel Obstruction, 2nd edition. Fast Facts and
Concepts. End of Life/Palliative Education Resource Center,
Medical College of Wisconsin.
• Catherine Weber and Gilbert B. Zulian. Malignant Irreversible
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