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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
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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 • 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
100 patients with OGIB Prospective, multicenter study 2 liters GoLytely+liquid diet day before Capsule did not reach cecum in 20% of studies [21 cases] Reasons for capsule failure: Slow gastric passage Unsuspected stricture Obstructing tumor Presence of food Technical failure No clear reason The Capsule Does Not Reach the Cecum in 20% of CE
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 • Obscure GI Bleeding • Chronic Diarrhea • Iron Deficiency Anemia • Abnormal SBFT/CTE • Abnormal Capsule Endoscopy • Peutz-Jegher Polyps • Refractory Celiac Disease • Retained Foreign Bodies • Intestinal Strictures • Crohn’s Disease • 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 • 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 • 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 • Sedation related adverse events • Perforation • Pancreatitis • Abdominal pain
Spiral Enteroscopy • 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 • GIE 2009;69;327-32
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 Mergener K et al, Endoscopy, 2007; 30: 805
Bulges Low Suspicion High/Moderate Suspicion Observe Repeat CE BAE/CTE Repeat CE Approach to Bulges 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? • 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
Older 40 Years Angioectasia GAVE NSAID enteropathy Dieulafoy Tumors Younger than 40 Years Tumors Crohn disease Meckel diverticulum Dieulafoy Celiac disease Etiology Based on Age
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 Radiographyin 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