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General Surgery
Small Bowel Obstruction
Built from Maingot's Abdominal Operations
What’s inside
10 sections · 186 slides
Overview
- Scope of this topic
Definitions and classification
The words a surgeon must use precisely
- Definition of bowel obstruction
- Levels of gut involved
- Mechanical versus functional obstruction
- Axes used to classify obstruction
- Partial and complete obstruction
- Simple and closed-loop obstruction
- Strangulation obstruction
- Reversible and irreversible strangulation
- Forms of complete mechanical obstruction
- How the causes of mechanical obstruction are grouped
- Causes of mechanical bowel obstruction
- Causes outside the bowel wall
- Causes within the wall and within the lumen
- Functional obstruction and pseudo-obstruction
- The word ileus and what it means where
- Causes of functional obstruction, ileus and pseudo-obstruction
- Causes of ileus inside the abdomen
- Causes of ileus outside the abdomen
- Postoperative ileus
- hours
- Reading the postoperative abdomen
- Early postoperative bowel obstruction
- Difficulty in separating it from ileus
How common and in whom
Frequency, changing causes and the burden of disease
- Distribution between small and large bowel
- How the causes changed over a century
- Local factors that change the causes
- 1 million
- Share of hospital work and outcome
- Mortality and recurrence
What obstruction does to the bowel
Distension, fluid loss, ischemia and bacteria
- Overview of the derangements
- Changing views of blood flow
- Distension and the source of the gas
- Inflammation within the bowel wall
- Fluid shifts hour by hour
- What drives the extra secretion
- Why the patient becomes dehydrated
- Sequence from blockage to systemic illness
- Motility early and late
- Nerves and the search for a drug
- Mechanisms that cut off the blood supply
- The ileocecal valve and the colonic closed loop
- Laplace's law and the cecum
- Self-reinforcing loop inside a closed segment
- Consequences of a failing blood supply
- Normal bacterial counts along the gut
- Bacterial overgrowth behind an obstruction
- Breakdown of the mucosal barrier
- Bacterial translocation in animals and in humans
- Why the altered bacteriology matters at operation
Causes of obstruction
Adhesions, hernias, tumours, volvulus and the rest
- Principal causes of small bowel obstruction
- Adhesions
- How adhesion formation begins
- Normal peritoneal healing
- Stages of normal peritoneal healing
- When healing turns into an adhesion
- How an adhesion matures
- Operations and timing of adhesive obstruction
- Long-term risk after an adhesive episode
- Hernia as a cause
- Which hernias threaten the bowel
- Gangrenous bowel from a strangulated inguinal hernia
- En bloc resection of a strangulated umbilical hernia
- Internal hernia after laparoscopic gastric bypass
- Internal hernia defects after Roux-en-Y gastric bypass
- Petersen's defect and diagnosis of internal hernia
- Trocar site hernia
- Richter's hernia
- Malignant obstruction
- Renal cell carcinoma deposit in the small intestine
- Crohn's disease and other granulomatous causes
- Intussusception
- Volvulus
- Sigmoid volvulus on plain film and contrast enema
- Cecal volvulus pointing to the left upper quadrant
- Sigmoid and cecal volvulus compared
- Small bowel volvulus around the world
- Other causes of obstruction
- Radiation change in the distal colon and rectum
- Radiation enteropathy of the ileum
Making the diagnosis
History, examination and laboratory tests
- Route to the diagnosis
- Classic symptoms
- High and low obstruction compared
- Character of the pain
- Pain as a sign of strangulation
- What to ask in the history
- What to do on examination
- Signs of advanced illness
- Listening to the abdomen
- The succussion splash
- Laboratory tests
- Markers of intestinal ischemia
Imaging the obstructed abdomen
Plain films, contrast, CT and the newer tools
- Plain radiographs
- Incomplete small intestinal obstruction on a supine film
- Complete small bowel obstruction on supine and upright films
- Fluid-filled small bowel loops in the left lower quadrant
- Reading the level from the film
- Fecalization of small bowel content
- Limitations of plain films
- Contrast studies today
- Barium enema showing complete large bowel obstruction
- Water-soluble contrast as treatment
- Trials that disagree
- Risks of contrast agents
- Computed tomography
- Accuracy of CT and scoring systems
- CT and bowel ischemia
- Cautions with CT
- Ultrasonography and magnetic resonance enterography
- Video capsule endoscopy
- Detecting ischemia and why it matters
- Ultrasound signs of strangulation
Management
Resuscitation, the nonoperative trial, and the operation
- Sequence of care on admission
- First steps for every patient
- Fluid resuscitation
- Electrolytes and antibiotics
- Nasogastric decompression
- Long nasointestinal decompression tube
- Nonoperative management: who qualifies
- Long-term outcome of the two approaches
- Absolute contraindications to a nonoperative trial
- The contrast transit test
- Complete obstruction as a relative contraindication
- “
- Reading that maxim carefully
- Running a nonoperative trial well
- Nasogastric tube technique
- Signs that force an operation
- Imaging findings that push toward operation
- How long to wait
- Preparing for operation
- Choosing the incision
- Finding the point of obstruction
- Exploring the whole abdomen
- Resection and anastomosis
- Decompressing the bowel at operation
- Handling bowel during decompression
- Judging bowel viability
- Bypass versus resection
- Laparoscopy for small bowel obstruction
- Reading the laparoscopy evidence carefully
- When to convert to an open operation
- Recurrent obstruction
- Older attempts to prevent recurrence
- Knowing when to stop an adhesiolysis
- What to do instead
- Preventing adhesions: the barrier idea
- Hyaluronate membrane
- Safety and value of barriers
Particular clinical settings
Early postoperative, after gastric bypass, radiation and cancer
- Early postoperative obstruction: first steps
- What CT adds early after surgery
- Obstruction within 10 days of operation
- Strangulation in the first 10 days
- Obstruction between 10 days and 6 weeks
- How long to wait before reoperating
- Obstruction after Roux-en-Y gastric bypass
- Commonest causes after gastric bypass
- Why obstruction after bypass is hard to diagnose
- Imaging and threshold after bypass
- Three internal hernia sites after gastric bypass
- Preventing and repairing internal hernia
- Radiation enteropathy
- Why operating on irradiated bowel is dangerous
- Choosing an operation in radiation enteropathy
- When bypass or adhesiolysis is better
- Obstruction in carcinomatosis
- Counselling and the trial of conservative care
- Obstructing rectal cancer treated by metal stent
- Minimal access and palliative surgery
- Bypass and decompressing tubes
Takeaways
What to carry away
- Takeaways: recognising the problem
- Takeaways: diagnosis
- Takeaways: treatment
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- Maingot's Abdominal Operations, 12th Edition