Obscure GI Hemorrhage

Dr Chintamani

MS, FRCS (Edin.), FICS,FIAMS

Examiner, MRCS The Royal College Of Surgeons Of Edinburgh

Vardhman Mahavir Medical College Safdarjang hospital New Delhi

GI Hemorrhage

Hemorrhage somewhere !

Hemorrhage nowhere !!

Hemorrhage in the small bowel….

Obscure GI hemorrhage

“Absence of an identified source of recurrent or persistent gastrointestinal bleeding after standard evaluation by upper endoscopy and colonoscopy”

Obscure GI Hemorrhage

Much of the small bowel mucosa out of reach of effective & readily available endoscopic devices.

Evaluation further complicated as it is episodic with early spontaneous cessation

Limits the use of dynamic imaging modalities like technetium 99m labeled RBC scintigraphy/selective visceral angiography

Typical patient with SBH

Multiple episodes of hemorrhage Subjected to numerous diagnostic

procedures Receives a mean of 20 units of packed

RBC before definitive identification & treatment of bleeding lesion

Occult OBH :anemia,fatigue,weight loss

Types

Overt obscure GI bleeding [obvious bleeding]

Occult obscure GI bleeding [positive Guaic stool test and /or iron deficiency anemia]

Occult variety

Difficult to evaluate[present with secondary signs]

Primary evaluation usually reveals the source from the upper GIT

Most of the remaining patients have a colonic source [benign& malignant]

<10% have anemia secondary to blood loss from small intestinal source.

“It is both the infrequency of bleeding from the small bowel and the diagnostic limitations of evaluating the small bowel that make the diagnosis and treatment of small bowel hemorrhage a vexing clinical problem”

Sources of obscure GI bleeding [findings in 71 adult patients treated by surgery]

Small bowel angiodysplasia 40%Small bowel leiomyoma/ adenocarcinoma 7%SB Lymphoma/ Crohn`s 6%Meckel`s 4%SB leiomyosarcoma 3%Metastatic colorectal cancer 3%SB varices/ melanoma 3%

Others 10% Szold et al Am J Surg.,163:90-93

Approach to OGIH

Delays in diagnosis and treatment are common

One must consider small bowel source when no identifiable lesion found in upper gastrointestinal tract or the colon

Multidisciplinary approach with radiologist, gastroenterologist, and surgeon

Blind surgical approach

Should be avoided Intra-operative assessment of

bleeding from small bowel is notoriously difficult to identify

Failed exploration is a frequent outcome

Presentation & initial evaluation

Attention to rapid resuscitation to maintain good tissue perfusion

Correction of existing coagulopathy <10% present with shock H/O multiple bouts of previous hemorrhage

that have failed to be effectively diagnosed or treated is highly suggestive

Persistent hemorrhage after initial evaluation is rare.

Symptoms of obstruction/pain may suggest malignancy

Investigations

Initial lab investigations: Hb% and hematocrit Platelet count PTTK PT

Hemodynamically stable patients Blood loss is usually less than 20%

of blood volume Brisk hemorrhage has stopped Persistent melena =>colonoscopy Typically blood found through out

colon Active hemorrhage arising from the

iliocecal valve diagnostic of small bowel hemorrhage

Hemodynamically unstable patients

UGI endoscopy to exclude major hemorrhage Evaluation of lower GIT follows Dynamic imaging modalities=> selective mesenteric

angiography or 99m Tc-tagged red blood cell scintigraphy

Marked hemodynamic instability =>selective visceral angiography initial investigation during aggressive resuscitation

Extravasation of contrast during selective mesenteric angiography=>temporary control using embolization of gel, sponge or coils or infusion of vasopressin and marking for future resection

99m Tc-tagged RBC scintigraphy Nuclear imaging modality to tag patient`s own RBC`s Older method using 99m Tc labeled sulfur colloid largely

abandoned Technique to document intestinal bleeding rates as low as

0.5ml/min Employed to identify potential source in patient with slow

to moderate ongoing blood loss. Patients with massive hematochezia and hemodynamic

instability angiography preferred. Actively bleeding patients the technique can identify site in

75% cases. In intermittent bleeding allows delayed imaging 3 to 36

hours if patient develops acute evidence of repeat hemorrhage.

Evaluation after an episode

In most cases ,bleeding ceases before a diagnosis is established during active hemorrhage

In these cases thorough evaluation of the upper and lower GIT by endoscopic examination

Beware of incidental findings !! Undirected surgical exploration in patients <30

years with massive hemorrhage Even these should undergo emergency upper

GI endoscopy to exclude bleeding from peptic ulcer

Modalities to evaluate small bowel:Stable patients after an episode

Enteroclysis Small bowel endoscopy Selective visceral angiography CT abdomen Meckel`s scan Wireless video assisted capsule

endoscopy

Enteroclysis

Modification of the technique of small bowel series Tube passed in to the duodenum and contrast

instilled under fluoroscopic control Yield of identification of occult source 2-20% [double

that of routine small bowel series] Low yield and interference with the immediate

angiographic studies because of retained luminal contrast limts their use in only those cases where bleeding has ceased

Good for mass lesions unlike vascular lesions ,the most common source of small bowel hemorrhage.

CT of abdomen

Spiral /Helical CT has replaced enteroclysis as the primary diagnostic test

Effective in small bowel neoplasms Inflammatory bowel disease

Selective mesenteric angiography

Provides the diagnostic and therapeutic options for temporary control of hemorrhage and marking of the small segment of origin

Angiodysplasia successfully evaluated in up to 60% of patients

Neoplasms and Meckel`s may also be detected

Small bowel endoscopy

“Push” small bowel endoscopy [More commonly used but the limitation in awake patient ]

Enteroscopy:AVmalformations,telangiectasias,diverticulae etc.

“Sonde pull” enteroscope

Intra-operative Enteroscopy

Gold standard for identifying occult sources of bleeding from small bowel

During exploratory laparotomy /laparoscopy endoscopist performs per-oral small bowel enteroscopy using pediatric colonoscope

Also through enterotomy

Meckel`s scans

Meckel`s diverticulae may contain ectopic gastric mucosa

Parietal cells in the gastric mucosa may take up Tc 99m detected on gamma camera

Meckel`s diveriticula most common cause of small bowel bleeding in patients < 30years of age

Wireless Capsule video endoscopy Tiny imaging capsule with a light

source,video camera,battery, antenna,radiotransmitter

Images of the intestinal tract transmitted twice each second

Signals are digitally recorded on a device that is later downloaded

Patient swallows the capsule in the morning & wears recording sensors for 8 hours

Wireless capsule video-endoscopy (WCVE) vs. Push enteroscopy WVCE have significantly higher yield vs

barium radiography, push enteroscopy and cross sectional imaging

* WVCE identified potential source of bleeding in 70% patients vs 45 % (PE)

* Pennazio et al.Endoscopy 2005 Oct;37(10)1046-50 ICCE consensus for obscure GI bleeding

Angiodysplasias/Vascular ectasias

Ectopic, thin walled vasculature due to degenerative disorders

Veins,venules,capillaries often lined only by endothelium

>50 years [5th and 6th decade commonest] Found throughout the gut Arise in the submucosa, extend to mucosa

when grow larger and bleed when eroded

Angiodysplasias Readily identified by angiography or by small bowel

endoscopy Incidence higher in chronic renal failure patients on

dialysis May present with overt or occult hemorrhage Optimum treatment controversial as <10% bleed

“ultimately” Most episodes stop spontaneously High rate of recurrent hemorrhage Since the bleeding develops in the 7th or 8th decade

morbidity of treatment becomes worse than the disease.

Angiography in Angiodysplasias

Hemodynamic instability => selective visceral mesenteric angiography

Intra-arterial vasopressin delivered at the rate of 0.2units/min through a catheter positioned as far distally in to the feeding vessel

Embolization with gel sponges,coils,other hemostatic agents ,a temporary measure before surgical resection

Risk of intestinal ischemia and infarction Other complications in elderly patients “Provocative angiography”

Endoscopic therapy in Angiodysplasias

Only bleeding angiodysplasias Thermal elctrocoagulation,laser or sclerotherapy Perforation is a rare complication Endoscopy preferred approach in patients with

multiple lesions or with adverse comorbidities Evaluation of the full small bowel requires

combined surgical and endoscopic approach

Surgery in angiodysplasias Super selective catheterization of each feeding

vessel with infusion of small bolus of methylene blue

Sites identified => resection of the segment Multiple angiodysplasias =>enterotomy with

suture ligation ,the secondary treatment of choice Intra-operative enteroscopy should be completed

at the time of exploration Medical treatment with conjugated

estrogen/Octreotide

Neoplasms Second most common cause 3-5% of all GI tumors 1/3rd of these lesions present with hemorrhage Most common from benign tumors like

hemangiomas ,schwannomas Malignant tumors present with obstruction/pain/

occult GI bleed Metastatic neoplasms: melanomas, Renal cell or

colonic in origin Diagnosis by CT,enteroclysis or angiography

depending on the features of the tumour

Carcinoids

Carcinoids have most favorable prognosis amongst small bowel tumours

>50 % five year survival *** Adenocarcinoids have poorer outcome Prognosis of small bowel tumours depends on

the stage at presentation

***Chintamani et al. Indian J Cancer,2005 Apr-Jun;42(2)99-101

Meckel`s diverticulum Most common cause of hemorrhage <30years Acid secreting parietal cell mucosa found in

70% of these diverticulae Bleeding is usually brisk Hemodynamic instability=> prompt exploration

following negative upper endoscopy to exclude ulcer disease

One of the few indications for a blind surgical approach in GI hemorrhage from small bowel source

Treatment is surgical resection

Pseudo-diverticulae of the small bowel

Far less common than colonic Hemorrhage complicates 5% of these Commonly, jejunum is involved Presence on enteroclysis not sufficient

to ascribe hemorrhage to these lesions Pooling of extravasated blood in the

diverticulum identified on endoscopy or after angiography

Other causes

Tuberculosis Bezoars *** Hemobilia Vascular (Aorto-enteric) Iatrogenic

***Chintamani et al. BMC Surg 2003 Sep 4;3:5

                                                                                                                                                 

                                                                                                                                                                        

Shows the retrieved cotton bezoar. The widest part was in the terminal ileum and the tail was extending in to the ascending colon and transverse colon also seen is the resected ileum.

**Chintamani et al. BMC Surg 2003 Sep 4;3:5

Summary Consider small bowel hemorrhage when upper and

lower GI studies normal In active (brisk) bleeding, technetium-99 radionuclide

scanning or angiography should be performed. Subacute presentation (or intermittent bleeding),

investigations should be broadened to include the small intestine

The most common bleeding sites include tumors and vascular ectasias,

30-50 years =>tumors the most common abnormalities <25 years of age => Meckel`s diverticulae. Older patients :Vascular ectasias