Endoscopic Imaging of the
Small Bowel
Surinder Mann MD
Professor of Clinical Medicine
Director of Small Bowel Endoscopy
UC Davis Medical Center
Introduction
• Enteroscopy is defined as direct visualization of small bowel with
use of fiberoptic or wireless endoscope
• Historically due to length and tortuosity of the SB , examination has
been limited to the most proximal and distal aspects
• Complete SB examination was only possible with intraoperative
enteroscopy.
• Development of newer enteroscopic imaging techniques since 2001
, more thorough evaluation of SB is possible
• New techniques include CE, BAE ( DBE & SBE ), Spiral
enteroscopy
• Enteroscopy currently has pivotal role in evaluation of OGIB,
Crohn’s disease , tumors and Celiac Disease
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Leighton JA Am J Gastroenterol 2011;106:27-36
Game Plan
• The Small Intestine: No Longer the Final Frontier
• What is Capsule Endoscopy (CE)?
• Clinical Applications of CE
• Limitations of CE
• Game Changers: Indications for CE+BAE in OGIB
“Disruptive Technology”
• Endoscopic
visualization of
entire small bowel
• Fiberoptic and
wireless endoscopes
• Paradigm shift in
workup of OGIB
• Evaluation of
Crohn’s disease,
celiac disease, small
bowel tumors, OGIB
What is Capsule Endoscopy?
• Allows for direct,
noninvasive examination
of the small bowel
without discomfort or
sedation
• 26 x 11 mm in size
• Images transmitted
wirelessly to data
recording device
• Gold standard in
evaluating small bowel
in OGIB
Clinical Applications of Small Bowel
Capsule Endoscopy (CE)
• Large retrospective and prospective clinical studies
have proven the superior safety and efficacy of CE
for the diagnosis of OGIB (Obscure GI Bleed)
• CE can be useful in diagnosing small bowel
tumors/masses
• Although limited, CE appears to be safe and useful in
the pediatric population
Treister et al. Am J Gastroenterol. 2005; 1002407-18
Moglia A et al. Lancet 2007; 370: 114-116
De’ Angelis GL. Am J Gastroenterol. 2007; 102: 1749-1757
Olympus CE and the Given SB Pillcam Are
Comparable for OGIB
• FDA trial
• Swallowed by the same
patient, 40 minutes
apart, randomized
• Read locally and
independently by 2
reviewers
• Overall agreement was
38/51, 74.5%, k .48,
• p = .008
Limitations of CE
• Incomplete examinations
• Poor preparations
• Limited mucosal visualization
• Rapid transit through particular segments
• Unidirectional field of view
• Interobserver variability
The Capsule Does Not Reach the
Cecum in 20% of CE
• 100 patients with OGIB • Reasons for capsule
failure:
• Prospective, multicenter
Slow gastric passage
study
Unsuspected stricture
• 2 liters GoLytely+liquid
diet day before
Obstructing tumor
• Capsule did not reach
Presence of food
cecum in 20% of studies
Technical failure
[21 cases]
No clear reason
Not Good!
Capsule Retention Occurs in .75% to
5% of All Studies
• Most cases occur in small bowel
• Risk factors: NSAID use, radiation, Crohn
disease
• Other causes: retention in diverticulae, tracheal
aspiration, cricopharyngeus impaction
Pennazio, Endosccopy 2004, 38:32-41
Barkin et al. Am J Gastro 2002, 87: A82
Indications of Deep
Enteroscopy
1. Obscure GI Bleeding
2. Chronic Diarrhea
3. Iron Deficiency Anemia
4. Abnormal SBFT/CTE
5. Abnormal Capsule Endoscopy
6. Peutz-Jegher Polyps
7. Refractory Celiac Disease
8. Retained Foreign Bodies
9. Intestinal Strictures
10. Crohn’s Disease
11. Small Bowel polyp removal/Bx/Tatoo
Unusual Indications
• Mid Gut Carcinoid
• ERCP in Roux-en-Y situations
• Abdominal symptoms in gastric bypass
patients
• Protein wasting enteropathy
• Jejunal Stenting
• PEG placement in Gastric bypass anatomy
• Previously failed colonoscopy
Double Balloon Enteroscopy
• Developed in 2001 ( Yamamoto and
colleagues ) and in practice US 2004
• DBE is now performed worldwide with
diagnostic & therapeutic options.
• Fujinon system and has diagnostic and
therapeutic scopes.
• Balloons are mounted at the tip of
overtube and distal end of scope.
Single Balloon Enteroscopy
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Olympus SIF- Q 180 Enteroscope
Length is 200 cm
Outer diameter 9.2 mm
Working channel 2.8 mm
Overtube 132 cm and silicone rubber balloon attached to
the distal end.
Outer diametr of overtube 13.2 mm & inner diameter 11
mm
100% Latex – free Silicone construction of overtube.
5.4 kpa –Set inflation pressure
8.2 kpa– Over pressure warning
-6.2 kpa – Set deflation pressure
Comparison with Double
Balloon Enteroscopy
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DBE available 2001- and clinical use in 2004
SBE availalable 2007
SBE is simple ( because it only has one balloon ), safe and takes 5 minutes to
prepare the system.DBE takes 15 minutes to prepare the system.
SBE can be performed by single endoscopist using standard conscious sedation.
SBE has intrinsic stiffness and does not require the use of a stiffening wire as needed
in DBE.
SBE Overtube/Balloon are silicon rubber and is Latex-Free
DBE can examine more length of SB as compared to SBE and DBE also has balloon
at the tip of scope.
Farthest point reached by both DBE/SBE is more via oral route than anal route.
Average procedure for SBE is 54 +- 18 minutes and for DBE 95 + - 41 minutes in
antegrade procedure.
Most of the total enteroscopy is not necessary as lesions mostly targeted by Capsule
endoscopy or other imaging studies.
DBE and SBE have similar array of therapeutics.
DBE and SBE have similar comlications.
Presence of varices is considered a contraindication.
Complications
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Sedation related adverse events
Perforation
Pancreatitis
Abdominal pain
Spiral Enteroscopy
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Newest enteroscope system
Endo-Ease Discovery SB ( Spirus Medical )
Spiral shaped overtube 118 cm, hollow spiral is 5.5 mm high and 22 cm long
Can be used antegrade or retrograde with enteroscope <9.4 mm in diameter
Advancement and withdrawal of enteroscope by rotatory clockwise and counterclockwise movements
Distal end of overtube stationed at 25 cm from tip of the enteroscope and locked into place
System is advanced up to ligament of Trietz with gentle rotation, collar is unlocked, enteroscope is advanced past
the ligament of Treitz with gentle rotation, collar is now unlocked , overtube is now advanced using clockwise
rotation until pleating of SB no longer occurs
Enteroscope is unlocked and now advanced further into SB
Withdrawal of the enteroscope is facilitated by rotating the overtube counterclockwise
Overtube also available for retrograde enteroscopy and difficult colonoscopy.
Preliminary data shows 33% diagnostic yield and average depth of 176 cm, another study showed 262+- 5 cm
depth of SB achieved
Severe Complications rate 0.3% and 0.27% SB perforation
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GIE 2009;69;327-32
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Lesion Missed on Given Pillcam and
Olympus Capsule!
Massive Bleeding from GIST Lesion
• 50-yo gentleman with
hematochezia
• Colonoscopy – full of
blood and clots
• Status post 7 u PRBCs
• Hgb at 8 with no change
• WCE – blood only
• DBE – ulcerated
submucosal mass
Proposed Classification of Mass
Lesions per International Consensus
Probability
of Tumor
Bleeding Ulceration
Irreg
Surface
Polyp
High
++
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++
Intermediate
+/-
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+/-
Low
Mergener K et al, Endoscopy, 2007; 30: 805
Approach to Bulges
Bulges
Low Suspicion
Observe
Repeat CE
High/Moderate
Suspicion
BAE/CTE Repeat CE
Leighton J. ACG 2010
Case: Obscure GI Bleeding
• 70-yo gentleman with iron deficiency anemia
• Laboratory evaluation
Hgb - 8
• Intermittent melena, no abdominal pain
• Endoscopic evaluation:
EGD and colonoscopy – normal
• Requires 2u prbcs transfusion ~ every month
• CTE normal
What Would You Do Next?
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Push enteroscopy
Second look endoscopy
Capsule enteroscopy
Nuclear scan/Angiography
Hematology consultation
Intraoperative Enteroscopy
Meckel scan
BAE
What Defines an Obscure GI Bleed?
“Bleeding from the GI tract that persists or
recurs after an initial negative evaluation
using bidirectional endoscopy and radiologic
imaging with barium contrast medium, such
as small bowel follow through (SBFT) or
enteroclysis”
Causes of Obscure GI Bleeding
• No studies to date on either the
frequency or location
• Within reach of a standard
endoscope
• Dependent on age
• Angiectasias account for 30-60%
of cases in obscure-overt gi bleed
• Upper, mid, lower classification
Etiology Based on Age
Older 40 Years
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Angioectasia
GAVE
NSAID enteropathy
Dieulafoy
Tumors
Younger than 40 Years
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Tumors
Crohn disease
Meckel diverticulum
Dieulafoy
Celiac disease
Exceptions to the Rule!
Many Lesions that Present as OGIB Are Actually
Missed Lesions Located Within Reach of a Standard
Endoscope
• Aim to determine incidence of
lesions within reach of a standard
endoscope
• 143 DBEs performed in 107
patients for OGIB
• Definite source of bleeding
outside the small bowel detected
in 24.2%
• EGD/colonoscopy w/in 1 week
• Most common lesions were
diverticula and angioectasias in
the colon
• If oral DBE negative, then
retrograde DBE
Should I First Perform Capsule
Enteroscopy or Push Enteroscopy to
Evaluate the Small Bowel?
Capsule Endosocopy Doubles the Diagnostic
Yield to That of Push Enteroscopy in Obscure GI
Bleeding
Triester et al. A Meta Analysis of the Yield of Capsule
Endoscopy Compared to Other Diagnostic Modalities in
Patients with Obscure Gastrointestinal Bleeding. Am J
Gastroenterol 2005; 100:2407-2418.
Capsule Endoscopy Is Far Superior to Small
Bowel Radiography in Obscure GI Bleeding in
Terms of Diagnostic Yield
Triester et al. A Meta Analysis of the Yield of Capsule
Endoscopy Compared to Other Diagnostic Modalities in
Patients with Obscure Gastrointestinal Bleeding. Am J
Gastroenterol 2005; 100:2407-2418.
What Can Improve the Diagnostic
Yield of CE in OGIB?
• Patients with hemoglobin <10 mg/dl
• Longer duration of bleeding (<6 months)
• Conversion of obscure-occult to overt (46% vs
60%)
• Greater than 4g drop in hemoglobin
• Performance of capsule within 2 weeks of
bleeding episode (91% vs 34%)
Leighton, J. ACG 2010
Capsule Enteroscopy Is Currently Recommended
as the Third Test of Choice for OGIB After
Negative EGD and Colonoscopy
• First prospective,
randomized study
comparing CE to PE
• Followed for 1 year
• Cross-over design
• Compared 2 strategies: CE
first or PE first
• Adjusted Odds Ratio = 3.22
in favor of CE first strategy
DeLeusse et al. Capsule Endoscopy or Push
Enteroscopy for First-Line Exploration of Obscure
Gastrointestinal Bleeding? Gastroenterology
2007;132:855-862
A Positive Capsule Enteroscopy Can Lead to
Improvement in Further Bleeding By Leading
to Definitive Therapy
Pennazio et al. Gastroenterology 2004; 126:643-653
DBE Is Favored Over CE in the Setting of
OGIB When Bidirectional
• Meta-analysis of 8 studies
comparing yield of CE to DBE
with the outcome as OR of the
yield
• Prospective studies
• No difference in overall yield
between CE and DBE (OR 1.61,
95% CI 1.07-2.43)
• But CE had significantly lower
yield compared to DBE using
combined antegrade+retrograde
approach (OR 0.12, 95% CI .03.52, p<.01)
DBE is Cost-Effective
• Median time to diagnose OGIB – 2 years (1 mo - 8 years)
• Average of 7.3 tests per patient w/half of those patients still
bleeding
• Costs associated with diagnosing OGIB - $33,360 per patient
• Case-Base Patient: 70-yo man with obscure-overt bleed from
small bowel angiectasias
• Compared PE, CE-guided DBE, DBE, angiography, IOE
• DBE – cost effective and highest success rate for bleeding
cessation
• CE-guided DBE to be best approach due to resources
Follow up On Case Study
• Diaphragm strictures
per CE and DBE at
proximal ileum
• Counseled on NSAID
cessation – all NSAIDs!
• Because of transfusion
dependence went for
surgical resection
• Resolution of anemia
Take Home Points
• Consider push enteroscopy as part of your
“second look” if BAE not readily available
• In most cases of OGIB do CE first
• Use CE as a guide to directing BAE route
• Deep enteroscopy may find bleeding sources
not detected by CE or other standard tests