Transcript ADHESIVE small bowel obstruction

ADHESIVE SMALL BOWEL
OBSTRUCTION
Leslie Kobayashi
Trauma Conference 2013
Overview
 Background
 Pathophysiology/Etiology
 Diagnosis
 Treatment
 Outcomes
Small bowel obstruction
(SBO)
 Mechanical obstruction of the small bowel
preventing free passage of intraluminal
material
 May be due to:
 Bowel wall inflammation, edema or tumor
 Intraluminal obstruction (bezoar, gallstone,
foreign body)
 Extrinsic compression (adhesion, hernia,
tumor, volvulus)
Background
 Obstruction is the most common
small bowel pathology requiring
surgical consultation
 Accounts for 20% of acute surgical
admissions
 Costs $800 million annually
Background
 Most common causes of SBO
 Adhesive 60-75%
 Malignancies 9-11%
 Hernias 8-18%
 IBD 5%
SBO in the virgin abdomen
 Historically
 Primary causes: hernia and volvulus
 Currently
 Primary causes: malignancy, IBD
 All cases of SBO in a virgin abdomen
should be taken for operative
exploration due to high failure rate of
NOM and concern for malignancy
Adhesive SBO
Pathophysiology
 Adhesions are fibrous bands of connective
tissue that form in response to trauma,
surgical manipulation, or inflammation
Peritoneal
Damage
Bleeding
Inflammation
Fibrinogen
Barmparas et al, J Gastrointest Surg
2010
Stable Fibrin matrix
Capillaries &
Migration of
Fibroblasts
Adhesion
Pathophysiology
 Postmortem study
 Minor procedure: 51% had adhesions
 Major procedure: 72% had adhesions
 Multiple operations: 93% had adhesions
 93% of 210 patients with abdominal
procedures, had intra-abdominal adhesions at
re-laparotomy.
Weibel MA. Am J Surg 1973
Menzies D. Ann R Coll Surg Engl 1990
Risk factors for SBO
 Age
 Comorbid conditions
 Prior surgery
 Stepwise increase with number of prior
procedures
 Surgical technique
 Open technique associated with
significantly higher rates of SBO
 Risk increased 2-8x’s
Procedure related risk
Technique
Total # of
patients
Adhesion-related
readmission
Appendectomy
Open
Lap.
266,695
4,445
1.4%
1.3%
Cholecystectomy
Open
Lap.
141
7,103
7.1%
0.2%
Colectomy
Open
Lap.
121,058
930
9.5%
4.3%
Ileal pouch-anal
anastomosis
Open
5,268
19.3%
Laparotomy for
Trauma
Open
1,913
2.5%
Gynecological
procedures
Open
Lap.
24,998
773
17.1%
0%
Surgery
Barmparas et al, J Gastrointest Surg 2010
Trends over time?
 ↓risk of SBO with laparoscopy compared
to open
 Laparoscopy rate ↑over time
 Has this resulted in ↓rate of SBO?
 No
Scott, et al Am J Surg 2012 and Angenete, et al Arch Surg 2012
Etiology
 Overall incidence of SBO 4.6%
 Top operations leading to SBO
 Appendectomy 14-30%
 Colorectal 21-34%
 Gynecological surgery 12-28%
Diagnosis
Diagnosis:
Clinical presentation
 Anorexia, nausea, vomiting, obstipation
(90%), constipation (80%), abdominal pain
 Abdominal distension, high pitched bowel
sounds, tympany, TTP, feculant NGT
output/vomitus
 Hypocholoremic, hypokalemic metabolic
alkalosis
Diagnosis:
Radiology findings
 Plain films
 Benefits: rapid, repeatable, no
contrast required, patient does
not have to be supine for
prolonged time period, can be
done at bedside
Diagnosis:
Radiology findings
 Findings:
 Distended loops of bowel
 Air-fluid levels
 Step laddering of bowel
 Lack of air in colon, rectum
Diagnosis:
Radiology findings
 CT scans
 Benefits: high sensitivity and
specificity (90%), gives information on
intra and extraluminal pathology,
highly sensitive for free air/fluid, can
identify transition zones, hernias, and
bowel ischemia
Diagnosis:
Radiology findings
 Findings:
 Dilated bowel
 Transition zone from dilated to
collapsed
 Passage of contrast material (partial)
or not (complete)
 Bezoars, masses
Treatment
Treatment
 Initial management of all patients
should include:
 NGT decompression
 Judicious fluid resuscitation
 Correction of electrolyte imbalances
 Foley catheter and close monitoring or
UOP
 +/- central venous and/or arterial catheters
Treatment
 Majority of cases (60-82%) can be
treated conservatively with nonoperative management (NOM)
 Three indications for Early
Operative Management (EOM):
1: Perforation
 Any patient with peritonitis or free
air-indicating perforation should go
straight to OR
Treatment
Peritonitis
Free air?
Yes
OR
2: Ischemia
 Any patients with concerning
signs/symptoms for gangrenous or
ischemic bowel should also go to the OR
ASAP
Signs of bowel ischemia
 Clinical: sensitivity 40-50%
 Hypotension
 Tachycardia
 Fever or leukocytosis,
 Lactic acidosis
 SIRS response
 Deterioration in exam
1983
Physical signs
Strangulated
Sensitivity Specificity PPV
(N=21)
Temp (°F)
99 ± 0.9
24
70
36
Pulse
104 ± 23
52
43
39
No bowel sounds
5/20
25
83
50
Peritonitis
6/21
29
97
86
2004
 Clinical symptoms, base deficit, leukocytosis,
blood glucose, and SIRS were assessed
 →SIRS and base deficit were independently
associated with gangrenous bowel
 Sensitivity: 92%, Specificity: 96%
 PPV: 92%, NPV: 96%
Signs of bowel ischemia
 Plain films
 Bowel wall edema, portal venous gas
 CT: sensitivity 85-90%
 Thickened bowel wall, target sign,
mesenteric stranding, congestion,
ascites, pneumatosis, portal venous
gas, decreased bowel wall
enhancement
Treatment
Peritonitis
Free air?
Yes
No
Ischemia?
Fever, Tachycardia, Acidosis
Portal air, pneumatosis, ascites
mesenteric stranding
OR
Yes
OR
3: High grade, or closed loop
SBO
 Patients with high grade SBO, or those with
closed loop obstruction should be strongly
considered for early operative management
Signs of high grade SBO
> 25mm
Air fluid width of
25 mm or more
Air-fluid levels of
differential height
in the same loop
Accuracy of plain X-ray to
diagnose a high grade SBO
 Sensitivity 66-75%
 Results of this technique are:
 Equivocal in about 20%–30%
 Normal, nonspecific, or misleading in
10%–20%
Maglinte AJ, AJR Am J Roentgenol 1997
Signs of high grade SBO
 Sensitivity 80-93%
 Contrast does not pass transition zone
 Colon with little gas or fluid
 Fecalization of small bowel
Diagnosis:
Radiology findings
 EAST Guidelines 2012
 Level 1 recommendation for CT scans
in SBO as they can provide incremental
increase in information compared to
plain films in differentiating grade,
severity and etiology that may lead to
changes in management
Treatment
Peritonitis
Free air?
No
Yes
Ischemia?
Fever, Tachycardia, Acidosis
Portal air, pneumatosis,
ascites mesenteric stranding
OR
No
Yes
OR
Closed loop or
high grade
SBO?
Yes-OR
Summary: treatment
 Three indications for early operative
management:
 Perforation
 Ischemia
 Closed loop or high grade obstruction
 All others can be considered for NOM
Treatment
Peritonitis
Free air?
No
Yes
Ischemia?
Fever, Tachycardia, Acidosis
Portal air, pneumatosis,
ascites mesenteric stranding
OR
No
Yes
OR
Closed loop or
high grade
SBO?
Yes-OR
No-obs
Principles of NOM
 Bowel rest, NGT decompression, fluid
resuscitation
 Serial abdominal exams and blood
tests, consider serial abdominal films
 Explore if deterioration in clinical exam,
or new e/o ischemia or perforation
 Keep in mind…
NOM
 Delay to OR is associated with:
 Longer LOS
 Increased incidence of bowel
necrosis and need for bowel resection
 Increased mortality
 Increased morbidity
NOM
 Given risks of delay to surgery:
 How long should NOM trial last?
 Studies suggest 48hrs although can
be longer in pSBO
 NIS data suggest delay of ≥4d
associated with 64% increase in
mortality and increased LOS
Schraufnagel et al, J Trauma 2013
Are there any decision
making aids?
NOM
 EAST Guidelines 2012
 Level 2 recommendation
 Consider water soluble contrast
administration for prognosis and/or
treatment in patients who fail to
improve within 48hrs
Water soluble contrast
 Hyperosmolar radiopaque agent
 Potential aid in prognosis
 Passage of contrast into LB may predict
successful NOM
 Failure of progression predicts need for OR
 Theoretically decreases bowel wall edema
and may promote resolution of SBO
Water-Soluble Contrast (WSCA) –
Diagnostic and Therapeutic role
Br J Surg. 2010 Apr;97(4):470-8.
•50–100ml Gastrografin or
40ml Urografin administered
orally
•Abdominal plain radiographs
after 4 h, 8 h or 24 h to follow
contrast through the GI-tract
Water-Soluble Contrast (WSCA) –
Diagnostic and Therapeutic role
Br J Surg. 2010 Apr;97(4):470-8.
Meta-analysis of 14 prospective randomized
controled studies
Water-Soluble Contrast (WSCA) –
Diagnostic and Therapeutic role
Br J Surg. 2010 Apr;97(4):470-8.
If the contrast reaches the colon within 4–24 h,
obstruction will resolve without operation in 99% of
patients.
Timing
4-8h
24h
n
312
196
Sensitivity
95
99
Specificity
99
97
PPV
100
99
NPV
85
97
Effect of WSCA: Need for surgery
Effect of WSCA: Hospital length of stay
Water-Soluble Contrast (WSCA) –
Diagnostic and Therapeutic role
Br J Surg. 2010 Apr;97(4):470-8.
 Conclusion
 Water-soluble contrast was effective in predicting
the need for surgery in adhesive SBO (sensitivity
96%, specificity 98%)
 In addition, it reduced the need for operation and
shortened hospital stay.
Outcomes
Outcomes
 Mortality 3-8%
 Rates of recurrence 15-20% over 5
years
 Rate of recurrence, # of recurrences,
and time to recurrence significantly
better in Operatively Managed
compared to NOM group
Outcomes
 California OSHPD database
 32,583 patients admitted in 1997 with
SBO
 76% NOM
 24% OM
 OM group associated with
 Decreased mortality, decreased rate of
readmissions, fewer readmissions, and longer
time to readmission
Foster, et al JACS 2006
Summary
1. Adhesions account for the majority of
SBO in the US
2. Clinical exam and xrays reliably diagnose
SBO
3. Early OM should be undertaken in
patients with perforation, ischemia, and
high grade or closed loop SBO
Summary: When to operate?
4. NOM successful in majority of patients,
but shouldn‘t exceed 4d
5. Consider use of Water-soluble contrast
agents for both diagnostic and therapeutic
purposes
6. Operative management can decrease the
rate and number of recurrences, and
prolong the time to recurrence