Anastomotic Leak

DEFINITION
Leakage of a gut anastomosis.
D E A B M I M


EPIDEMIOLOGY
Not uncommon.
Certain anastomoses are prone to leaking.
- perhaps <5% of colonic anastomoses.
- up to 10% of anterior resections.
- particularly where a very low rectal stump.
- 15-20% of pancreaticojejunostomy anastomoses (lumen matching technically difficult).
D E A B M I M

AETIOLOGY

Risk Factors
Technique:
- tension
- poor anatomical blood supply (particularly post anterior resection)
- unrecognised mesenteric vessel damage
- poor suture technique
Local factors:
- obstruction
- ischaemia
- peritonitis
Systemic factors
- shock
- age
- malnutrition
- immunosuppression
D E A B M I M

BIOLOGICAL BEHAVIOUR

Natural History
Typically occur between days 4-8 post-op.

Pathophysiology
Consider the above risk factors
These may be prevented by considering anastomitic healing before, during and after surgery.
- was perfusion compromised during the operation in any way?
- were the vessels supplying the anastomosis adequate?
- was there post-operative hypotension?
See management for preventation of leaks.

D E A B M I M

MANIFESTATIONS

Symptoms

Almost an infinite variety of presentations.
- from catastrophic collapse and septic shock
- to subtle changes in vital signs.
Gut function is usually delayed or absent.
May have pain
Malaise and failure to thrive.

Signs
Fever / signs of SIRS
A high index of suspicion is needed.
- frequent reassessment is valuable.
- have a low threshold for obtaining imaging studies.

Abdo possibilities

Fullness in area of leak.
Wound dehiscence.
Fistula development.
Extensive erythema.
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INVESTIGATIONS

Investigate as for SIRS

Imaging
Conduct immediate CT if there is any suspicion.
- rectal contrast can be helpful.
Features
- large fluid collections
- air-fluid levels
- large amount of free-fluid or air
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MANAGEMENT

Prevent leakage
- optimise patient nutrition prior to surgery
- meticulous mobilisation
- preserve blood supply carefully
- minimise manipulative trauma
- carefully placement of suture / staple lines
Tips to ensure a healthy anastomosis:
1) Blood supply must be adequate to edges to allow healing.
2) Tension-free anastomosis must be met (take time to mobilise fully).
3) Place each suture / staple correctly.
4) Accommodate the lumina to match.
5) Handle tissue gently, no crushing to edges.
6) Optimise visualisation of the anastomosis.

Anticipate anastomotic leakage
- ileostomy cover employed for high-risk anastomoses
- never let vanity get in the way of a 'second look'

When a Leak Occurs:
Immediate judicious managment.
Surgical or radiological intervention is often needed.
Depends on the site and operation.
- bowel often best exteriorised as stoma, particularly when circumstances are otherwise unfavourable.
If infection not controlled, probably need to operate.
Otherwise USS or CT-guided percutaneous drainage & conservative management might be employed for contained / small leaks.
Treat a fistula as usual.
Nutritional support is frequently required.
D E A B M I M


REFERENCES
CCrISP Manual.
Sabiston's 17th.