1. OBSCURE GI BLEED Talat Bessissow, MC CM, FRCPC
Assistant Professor, Department of Medicine
Division of Gastroenterology
McGill University Health Center

2. Definition
Definition = GI bleeding of uncertain etiology after EGD, C-scope, and small bowel radiography
Overt OGIB = hematochezia, melena, hematemesis or CG emesis
Occult OGIB = FOB + in abscence of visible blood, Iron deficiency Anemia

3. Fecal occult blood testing
Guaiac-based tests: The pseudoperoxidase activity of hemoglobin turns the guaiac compound blue in the presence of hydrogen peroxide

5. Epidemiology
300,000 pts hospitalized/yr in US ... 5% of these will have normal EGD and C-scopes
Median time for diagnosis is 2 years
Average cost $33,630 per patient
Average 7.3 tests per patient
Paradigm shift since introduction of VCE and DBE

6. Etiology of Obscure GI Bleeding
5% of patients presenting with GI hemorrhage have no source found by upper endoscopy and colonoscopy.
Of these, 75% are 2ndry to small bowel lesions
Of these, 30-60% angiectasias
Am J Surg 1992;163:90–92
Br Med J (Clin Res Ed)1984;288:1663–1665.

7. Etiology of Obscure GI Bleeding
Upper and lower GI bleeding
overlooked
Mid GI bleeding
Cameron’s erosions
Tumors
Fundic varices
Meckel’s diverticulum
Peptic ulcer
Dieulafoy’s lesion
Angiectasia
Crohn’s disease
Celiac disease
GAVE
Neoplasms
NSAID enteropathy
Erosive gastritis
Hemobilia
Ischemic colitis/UC
Aortoenteric fistula
Large polyps
Vasculitis

8. Etiology 40% of OGIB - due to angiectasias (AVMs)
Angiectasias : ectatic blood vessels made of thin wall with or without endothelial lining
Natural history of angiectasias is not well known
Only 10% of all patients with angioectasia will eventually bleed
Once a lesion has bled up to 50% will not rebleed --- predictors of rebleeding: multiple bleeding episodes, transfusion requirement
Bleeding angiectasias are associated with abnormal von Willebrand’s factor (vWF)

9. AVM Conditions/diseases associated with angiodysplastic lesions:
Elderly
CRF
Aortic valve disease (Heyde’s syndrome)
Cirrhosis
Collagen vascular disease

10. AVM

11. What is Heyde’s syndrome ?
Heyde’s syndrome: Bleeding from angiectasias in patients with AS.
Increased consumption of high-molecular-weight multimers of VWF due to shear stress of the abnormal valve which corrects after aortic valve replacement with decreased severity of bleeding
Transfus Med Rev 2003;17:272–286.; Abdom Imaging (2009) 34:311–319

12. Small Bowel Bleeding Etiology depends on the age of the patient
Young: small intestinal tumors, Meckel’s diverticulum, Dieulafoy lesion, Crohn’s disease
Older: (>40) vascular lesions, NSAID-induced SB disease
Uncommon: hemobilia, hemosuccus pancreaticus, aortoenteric fistula

13. History and Physical Examination
The nature of the exact presenting symptom is important in deciding a practical, efficient, and cost-effective evaluation plan
Hematemesis indicate upper GI bleed
Melena can be anywhere from the nose to the right colon
Hematochezia can be a lower GI bleed or a fast upper GI bleed
History of medications (mainly OTC)
Family history
Skin signs

14. Hereditary hemorrhagic telangiectasia

15. Blue rubber bleb nevus syndrome

16. Dermatitis herpetiformis

17. Plummer–Vinson syndrome

18. Tylosis

19. Investigation options
Repeat G & C
CTE
Capsule endoscopy
Enteroscopy - push or SBE/DBE
Angiography
Tagged RBC scan

20. Common lesions that are overlooked
EGD: Cameron’s erosions, fundic varices, PUD, angioectasias, Dieulafoy lesion, GAVE
C-scope: angioectasias, neoplasms

21. Investigation
Repeat standard endoscopy, especially if anemia and overt GI bleeding:
Overlooked lesions: fundus
high lesser curvature
antrum
C loop of duodenum, posterior wall of duodenal bulb
Random SB Bx can be + for celiac disease in up to 12%
The yield of repeat colonoscopy is 6%, yield of repeat EGD is 29% (ASGE)
Am J Gastroenterol 1996;91:2099–2102

22. Investigation Gastroenterology 2002;123:999–1005
Consider side-viewing scope if pancreatobiliary pathology is suspected
Small bowel series/SBFT:
When compared with capsule endoscopy
diagnostic yield 8% vs 67%
clinically significant finding 6% vs 42% (NNT 3)
Used if SB obstruction is suspected
Gastroenterology 2002;123:999–1005

23. Investigation CT Enterography:
Thin sections and large volumes of enteric contrast material to better display the small bowel lumen and wall.
Neutral enteric contrast + IV contrast
1.5 – 2 L of milk, PEG electrolytes or low-concentration barium

24. Investigation CT Enterography:
Advantages: displays entire wall thickness
examination of deep ileal loops
mesentery & perienteric fat
no need for NGT

25. CTE

26. Investigation Technetium-99m–labeled RBC scan: Limited value
Blood loss of ml/min (2U PRBCs /d)
Poor localization of SB bleeding - not enough to direct operative therapy
Angiography:
Useful in massive bleeding (>0.5ml/min)
Diagnostic & therapeutic
Nucl Med Commun 2002;23:591–594

27. Investigation Endoscopic imaging: Intraoperative enteroscopy;
Terminal ileum can be reached in 90% of cases
diagnostic yield 58-88%
mortality up to 17%

28. Investigations Push enteroscopy: Length 220-250 cm
usually limited to 150 cm
diagnostic yield up to 70%
angioectasias in up to 60%
some suggest push enteroscopy over repeat EGD as second look

29. Capsule endoscopy Size 11x26 mm
Obtains images and transmits the data via radiofrequency to a recording device
The capsule is disposable
Examination takes at least 8 hours (57,600 images)
Reading 60 – 120 minutes
SB obstruction is a contraindication

30. Capsule endoscopy Capsule endoscopy:
yield 63% vs 23% for push enteroscopy
Sensitivity %
Specificity 75 – 95%
+ve predictive value 97%
-ve predictive value 86%

31. 36-92% 41-63% 42-57% + 30% + 36% Diagnostic Yield
Obscure/Overt GI Bleeding
36-92%
Obscure/Occult GI Bleeding
41-63%
Unexplained Fe-def Anemia
42-57%
Yield Gain Over Push Enteroscopy
+ 30%
Yield Gain Over SB Barium Study
+ 36%
Lin, GIE 2008
Rastogi et al. GIE 2004
Pennazio et al. Gastroenterol 2004
Apostolopoulos et al. Endoscopy 2006
Estevez et al. Eur J Gastro Hep 2006
Delvaux et al. Endoscopy 2004

32. Pennazio 2004, Gastroenterol
Superior yield to other diagnostic modalities in both active and inactive obscure GI bleeds
Study
Sens (%)
Spec (%)
PPV (%)
NPV (%)
Pennazio 2004, Gastroenterol
88.9 95 97
82.6
Hartmann 2005, GIE 75 86
* Marmo, APT 2005, Triester, AJG 2005, Saperas AJG 2007

36. Double Balloon Enteroscopy
Double Balloon Enteroscopy (DBE)
1st described in 2001
200-cm enteroscope
140-cm overtube

39. Double Balloon Enteroscopy (DBE)
Antegrade approach:
mean distance  240 +/- 100 cm
mean time  /- 23 min
Retrograde approach:
mean distance  140 +/- 90 cm
mean time  75 +/- 28 min

40. How Effective is DBE? Study Diagnostic Yield (%)
Kaffes 2004, Clin Gastro Hep 76
Mehdizadeh 2006, GIE 51
Yamamoto 2006, Am J Gastro
Jacobs 2007, GIE 75
Tanaka 2008, GIE 54
Yadav 2010, abstract DDW
52%

41. CE favoured although nearly equivalent
How Effective is DBE?
Study
Patients (n)
Yield
Matsumoto 2005, Endo 13
Equivalent
May 2005, GIE 52
DBE better
Hadithi 2006, Am J Gastro 35
CE better
Mehdizadeh 2006, GIE
115
Ohmiya 2007, GIE 74
Kameda 2008, J Gastroenterol 32
Teshima 2010, DDW (Meta-)
1293
CE favoured although nearly equivalent

42. Complications Perforation – 0.3-1.1%
Bleeding (post-polypectomy) – %
Pancreatitis – %
Melsink Endoscopy 2007, Gerson ACG 2008

43. Single Balloon Enteroscopy
Much more recent
Simpler to set up, works with existing Olympus equipment
Same specifications as DBE without the second balloon on the endoscope
Hartmann, Endoscopy 2007

44. Single Balloon Enteroscopy
Kawamura GIE 2008

45. SBE versus DBE Efthymiou, abstract 2010
RCT involving 79 patients recruited for mainly OvGIB/ObGIB
About half had SBE
Depth of insertion retrograde was identical (100 cm)
Depth of insertion orally favoured DBE (250 versus 205 cm but not significant)
Therapeutic yield was 54% DBE, 37% SBE (not significant)
Targetted biopsies or application of cautery or argon plasma

46. Pennazio et al. Endoscopy 2005 & AGA Technical Insitute
Pennazio et al. Endoscopy 2005 & AGA Technical Insitute. Gastroenterol 2007