Evaluation of Obscure Gastrointestinal Bleed

Omar Badrin Masters of Surgery

Definitionbleeding from the GI tract that persists / recur without obvious cause after initial endoscopic evaluation

Occult : non visible bleeding, positive for FOBT and anaemia (iron deficiency anemia)

Overt : visible bleeding presenting as melena or hematochezia

Overt can be active or inactive bleed.

how much do we miss?

• Endoscopy during or immediately after an acute bleed misses the source in 35 - 75% (Chen RY Anz J Surg 2002)

• Half missed upper GI lesions are in the fundus (Decamps C Endoscopy 2009)

• With early endoscopy & good bowel preparation, still 3 - 5% bleeding source undetected (Leighton J Gastrointestinal Endoscopy 2003)

how much do we miss?

• 25% of these are due to missed lesions in the upper and lower GI tract (Tee H P World J Gastroenterology 2010)

• 75% are from small bowel, majority of which are vascular abnormalities. (Tee H P World J Gastroenterology 2010)

why do we miss the bleed?

• no active bleed on endoscopy

• lesions are obscured by blood and clot

• hypovolaemia and anemia

• untrained eye

what we missUpper GI Lower GI

Fundal varices Cameron’s ulcer

Mallory Weiss tear Gastric antral vascular ectasia

Dieulafoy’s lesion Hemobilia

Meckel’s diverticulum Angiodysplasias

IBD Aortoenteric fistula

common causes

< 40 years

IBD

Meckel’s

Dieulafoy’s lesion

Small bowel tutors

> 40 years

vascular lesions

drug related erosions / ulcer

tumors

Fundal varix

Cameron’s ulcer

Mallory Weiss tear

GAVE

Dieulafoy’s lesion

Angiodysplasia

Meckel’s diverticulum

Aorto-entertic fistula

Evaluation• localizing source of bleed [ upper vs lower ]

• exclude non GI sources [ENT bleeds]

• surgical history [AAA repair]

• drug history

• family history:

colorectal or endometrial malignancy [FAP & Lynch syndrome]

neurofibromatosis

Peutz Jagher Syndrome

Kaposi sarcoma

Repeat Upper & Lower endoscope

• 1st step in most centres & practices

• detection rate after initial assessment ranges between 2.8 - 4.8% in upper endoscopy studies (ASGE Fischer J Gastrointestinal Endoscopy 2010)

• rescoping detection rate 3.5% of 174 patients prior to capsule endoscopy (Vlachogiannakos J Dig Dis Sci. 2011)

• missed lesions are: Cameron’s ulcer, peptic ulcers / erosions, GAVE & Dieulafoy’s lesions

• not economical

• based on centres

Video Capsule Endoscopy (VCE)

• non invasive, examination of entire small bowel, safe & diagnostic yield

• no biopsy or therapeutic capability, small bowel folds, unable to locate lesion & risk of retention

• detection of clinically significant lesion by VCE 56% vs PE 26% vs small bowel study 6% (ASGE Fischer J Gastrointestinal Endoscopy 2010)

• 2nd VCE after -ve initial VCE study, detection rate 49% (ASGE Fischer J Gastrointestinal Endoscopy 2010)

VCE• VCE in detecting overt % occult bleed: 100% vs

67% (Hartmann D et al Gastrointest Endosc. 2005)

• VCE vs PE as first line study: detection rate 50% vs 24%, missed lesion 8% vs 24% (lesions detected on standard endoscopy) (de Leusse A Gastroenterology. 2007)

• VCE vs small bowel study: detection rate 20% vs 5%, diagnostic / therapeutic intervention 26% vs 21%. concluded - detection rate is improved, outcome is still the same. (Laine L, Sahota A, Shah A Gastroenterology. 2010)

Enteroscopy• after -ve VCE study

• Types: Push, Deep (single/double balloon, spiral) & intra-operative

• based on design of an over-tube

• diagnostic and therapeutic

• invasive, discomfort

• detection rate 70% (ASGE Fischer J Gastrointestinal Endoscopy 2010)

• most common detected lesion: angiodysplasia, erosions

• most lesions are within reach of standard endoscope

Intra-operative enteroscopy• either through an enterotomy, or upper / lower

endoscope (telescoping)

• examination of 90% of bowel length

• detection rate up 60 - 88% (ASGE Fischer J Gastrointestinal Endoscopy 2010)

• morbidity: serosal tear, hematoma, ileus, ischemia & perforation

• for recurrent overt bleed, high transfusion requirement

• 41 cases 1995 - 2005

• 12 cases angiodysplasias, 8 cases of Crohn’s, 5 with carcinoid, 5 with hamartomas, 4 with lipomas and others

• described procedure as:

1. midline laparotomy

2. examination of small bowel

3. circular stay suture for enterotomy of the proximal bowel

4. introduction of enteroscope, telescoping through small bowel

5. distal bowel clamping for insufflation (prevent over inflation)

Imaging

Small bowel study

1. low detection rate 0 - 5.6% (ASGE Fischer J Gastrointestinal Endoscopy 2010)

2. large luminal / fungating lesion

3. unable to detect flat mucosal lesion

4. contrast may mask active bleed for endoscopy

Radionuclide scan• overt GI bleed

• bleed rate 0.1 - 0.4 cc/min

• RBC tagged with technetium 99m

• poor with localising small bowel lesions

• also Meckel’s scanning in children and young adult with obscure GI bleed

CT mesenteric angiogram

• non invasive

• small bowel IBD

• recent multiphasic CT enterography can detect small vascular lesion [44% of 22 patients, 3 of which were missed on VCE] (Huprich J, Fletcher J, Alexander J, et al. Obscure gastrointestinal bleed- ing: evaluation with 64-section multiphase CT enterography: initial ex- perience. Radiology 2008)

•

Selective angiography• bleeding rate 0.5 cc/min

• better at localising

• detection rate 22 - 77% (Zuckerman GR Gastrointest Endosc 1998)

• selective embolisation (Tan K-K World J Surg 2008)

•

Managementovert occult

stableunstable

resus

repeat scope

CT angiograpgy angiogram

Laparotomy IO scope

repeat scope

VCE

VCE or PE or CT enterography

Deep enteroscopy

-ve

-ve

-ve

-ve

-ve

-ve

take home• careful endoscopy is essential

• VCE as first line in occult bleed

• type of enteroscopy will depend on level of bleed

• intraoperative enteroscopy is not without complications