Analytical approach of

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Analytical approach of Gastrointestinal bleeding
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Dr Nor Hayati Othman Associate Professor and
Head Depar6ment of Pathology USM
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(No Transcript)
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GASTROINTESTINAL CIRCULATION
Celiac axis superior mesentric artery inferior
mesentric artery anastomotic connections
Anastomotic connections sup.and inf pancreatico
duodenal a. marginal a. of Drummond arc of
Riolan splenic flexure
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Embryology/anatomy/histology

• STOMACH
• Derived from foregut
• 4 anatomic parts cardia, fundus, body, pylorus
• 3 layers of wall mucosa (include muscularis
  mucosa),
• submucosa, muscularis propia
• 3 layers of muscle coat longitudinal, circular
  and oblique
• Variable mobility body mucosa - rugose and
  freely mobile
• antral mucosa firmly anchored
• Generous arterial blood supply coeliac, hepatic,
  splenic
• Abundant arterial anastomosis-EXCEPT lesser curve
  and
• 1st part duodenum
• Distinct mucosalarterial vasculature - supplied
  by extramural
• end arteries

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Why do patients bleed?

• Due to mass effect
• Not due to mass effect

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Due to mass effect

• Mass erodes blood vessels
• Mass alters the normal route of the vessels
• Mass is accompanied by growth of numerous
  abnormal , fragile vascular channels
• Mass is of vascular origin

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Not due to mass effect

• Lesions that ulcerate the GI mucosa
• GI Ischaemia/infarction
• GI Varices
• GI infestation/infection
• Liver diseases
• Pancreatitis
• Bleeding diathesis
• Drugs

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Mass eroding blood vessels
Mucosal lesions - eg adenoca of stomach Mural
lesions - eg GIST, lymphoma Tumours with
angioinvasive potential- eg choriocarcinoma(20)
mech of bleeding
GIST gastrointestinal stromal tumour mass
arising fr the mesenchymal coat push and
stretch the surface mucosa surface mucosa
ulcerate
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GIST ulcerating the mucosa
mucosa
Benign of malignant GIST, effect on mucosa is
similar rate of growth differ
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Mass altering the route of mucosal blood vessels
gastrointetinal polyps- neoplastic
(adenomas)- tubular, - villus,
- tubulovillous non neoplastic
hyperplastic regenerative, inflammatory,
harmatomatous
-
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mech of bleeding
gastrointetinal polyps- bleeding both from the
sessile and pedunculated new
vessels from original vessels
mucosal vessels tortuous

young mucosa (fragile) protrude into lumen

easily ulcerate
-
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adenoma
Risk of bleeding Villous gt tubular villous gt
tubular
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Mass accompanied by growth of abnormally fragile
vessels
Mucosal lesions - Adenocarcinoma Neuroendocr
ine carcinoma Mural lesions Carcinoid
tumours Gastrointestinal stromal tumours
(GIST) Lymphomas PNET Inflammatory fibroid
polyp Fibrohistiocytic tm Endothelial/vascular
tumours
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Mass accompanied by growth of abnormally fragile
vessels
mech of bleeding

• Growing tumour secrete angiogenetic factor
• Many new cappilaries are formed
• The rate of vasc formation is // to degree of
  differentiation
• The faster these vessels are formed, the more
  fragile they are

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Mass of vascular origin
Non Neoplastic Primary vessel disease Large
vessel disease Small vessels Ds Vascular
malformations Vascular ectasia AVM Neoplastic
hemangiomas hemangiosarcomas Lymphangiomas Kap
osis sarcomas
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Large vessel disease Polyarteritis
Nodusa Takayasus disease, Giant cell
arteritis Thromboangitis obliterans Small
vessels Ds HSP Connective Ts Ds GI
Fibromuscular dysplasia Wegerners
Granolomatosis
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• Polyarteritis Nodusa
• Systemic disorder
• GI involvement 50 of cases
• Involve medium sized mesentric vessels
• aneurysmal dilation if only a segment of the vs
  affected
• Us. intra-abd or retroperitoneal bleeding
• may thrombosed ---gt mucosal ulceration
• charecteristic histology

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• Connective tissue disease
• SLE, RA, Scleroderma, dermatomyositis
• Vasculitis----gt
• mucosal ulceration, infarction,perforation
• histology small and large artery-- obliterative
  endarteritis with or without fibrinoid necrosis

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• Vascular ectasia
• elderly
• right colon, stomach
• terms - angiomas, angiodysplasia, avms
• Associated with aortic stenosis, von Willibrand
  ds
• grossly - small, multiple
• easily identified but angiography but not biopsy
• Pathogenesis not clear - postulation due to low
  grade obstruction of submucosal colonic veins---gt
  leading to loss of precappilary sphincter----gtav
  shunts---gtectatic channels

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I am yawning!!
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Not due to mass effect
Lesions ulcerating mucosa erosive/hemorrhagic
gastritis Reflux disease Barrets
esophagitis Peptic ulcer disease
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Not due to mass effect
normal
Erosive hemorrhagic gastritis
Peptic ulcer
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mech of bleeding

• Erosive hemorrhagic gastritis/peptic ulcer
  disease
• critically ill patients
• NSAID, active alcoholics, drugs
• Loss of maintainence of mucosal intergrity

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mech of bleeding

• Maintainence of mucosal intergrity
• Mucus and bicarbonate action
• Prostaglandins
• Mucus and bicarbonate action
• mucus from surface and neck columnar cells
• glycoprotein gel coat the surface
• bicarbonate fr. Surface epith cells
  --gtglycoprotein gel
• mucus neutralize hydrogen ions that diffuse from
  the lumen into the mucus gel
• mucosa is in contact with neutral fluid,
  regardless the amount of acid

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mech of bleeding

• Prostaglandins
• protect gastric mucosa -----gt cytoprotection
  (mucosal protection)
• how ?
• Increase in bicarbonate and mucus secretion
• increase blood flow
• increase cell renewal

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mech of bleeding

• Erosive hemorrhagic gastritis/peptic ulcer
  disease
• critically ill patients
• NSAID, active alcoholics, drugs
• Loss of maintainence of mucosal intergrity
• Mucous and bicarbonate secretion by surface
  epith.
• Loss of glycoprotein gel which adheres to surface
  
• Loss of acid neutralizer action by bicarbonate

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GASTROINTESTINAL ISCHAEMIA /INFARCTION
mech of bleeding
hypoxia, throboembolic ds vasoconstriction etc,
ischaemia necrotic mucosa/underlying wall
including vessels shed of GI bleeding
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GASTROINTESTINAL ISCHAEMIA /INFARCTION
infarcted
normal
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• SUMMARY
• GI bleeding can be caused by
• masses in the gastrointestinal tract
• eroding the mucosal vessels
• altering the normal course of the vessels
• forming fragile vessels
• destroying resident vessels
• vascular in origin

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• SUMMARY
• GI bleeding can be caused by
• no masses in the gastrointestinal tract
• diffuse ulcerative lesions
• disturbance in its vascular supply such as
  infarction/ischaemia
• variceal formation due to liver disease and
  portal hypertension
• systemic diseases such as connective tissue
  diseases
• Bleeding diasthesis due to DIVC as a result of
  stress,coagulation disorders etc

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Thank you