Acute LGIH (lower gastrointestinal haemorrhage)
Abnormal intraluminal blood loss from a source distal to the ligament of Treitz.
Acute haemorrhage is continuous, gross bleeding from the rectum (patients may present as haemodynamically stable or unstable, detection and localisation of the origin of bleeding is critical to patient management)
Causes of LGIH
Major LGIH:
Diverticular disease Angiodysplasia
Minor LGIH: Haemorrhoids Fissures Perianal disease Proctitis
Common sites for LGIH
Sites
•Colon – 95-97%
•Small bowel – 3-5%
Finding the site
•Intermittent bleeding common •Up to 42% have multiple sites
Pathology
Most diverticulosis is located I the left colon (60%)
Diverticula of the right colon tend to bleed more often with 60%-80% of diverticular bleeding being of arterial origin in the right colon.
20% of people with diverticular disease will experience bleeding.
5% will experience massive haemorrhage.
- Colonic angiodysplasia are acquired lesions.
- Typically multiple, painless, small and occur in the right colon
- Angiodysplasia are degenerative lesions.
- Increasing incidence with age.
- Angiodysplasia tend to cause slow and repeated episodes of capillary and venous bleeding
Management
- Characterise: patient history and physical examination (upper or lower GIT).
- Resuscitate: intervention to stabilise physical condition (e.g. hypotension, level of consciousness).
- Differentiation and localisation: type of bleed (acute, occult, overt), bleeding rate (severity), detect and locate the bleeding site (colonoscopy, angiography and scintigraphy).
- Treat: stop the bleeding and prevent recurrent bleeding (colonoscopy, angiography and surgery).
Signs and symptoms
Depends on the site of origin, the severity of bleeding and the presence of coexisting disease.
Five different presentations of gastrointestinal haemorrhage:
• Haematemesis is bloody vomitus which can be bright red blood or matter of ‘coffee ground’ appearance.
- Melena results from degradation of blood in the GIT and is characterised by black, tarry stools with a foul odour.
- Haematochezia is generally associated with the passage of bright red or maroon blood from the rectum and may be in the form of bloody diarrhoea or blood mixed with a formed stool.
- Occult blood loss is generally only detected by laboratory examination of the stool.
- Anaemia or other symptoms of blood loss.
- Chronic blood loss may cause fatigue, lethargy, dyspnea, anaemia or pallor.
Alternative tests
- Nothing specific
- Whole blood counts – anaemia
- Electrolytes
- Faecal occult blood test
Diagnostic Conundrum (confusing problem)
- The origin of bleeding may be anywhere in the GIT.
- Bleeding is frequently intermittent.
- Evidence of active bleeding may not be obvious until after bleeding has ceased.
- Emergency surgery may be required for both a specific diagnosis and localisation of the bleeding site.
- Post therapy recurrence of bleeding is common.
- There is no consensus on appropriate patient management.
CT angiogram - diagnostic only (non-invasive)
• Determines site and cause of bleeding
Mesenteric Angiogram -diagnostic and
therapeutic (but invasive)
- Determines site of bleeding and allows embolisation of bleeding vessel
- Can result in colonic ischaemia
Nuclear Scintigraphy – 99m-Technetium
labelled red blood cells: diagnostic only
Determines site of bleeding only (not cause)
Benefits:
- Wide window of opportunity (hours) for imaging intermittent bleed
- Cheap, safe and non invasive
- Readily available
Limitations:
- Localisation, especially with retrograde and integrate migration
- High background activity
Colonoscopy
- Defines the anatomic cause
- Doesn’t require active bleeding
- Delay due to bowel preparation
- Not during active bleeding (increased risk of perforation)
- Positive associated with stigmata
- Treatment option but stigmata may not be source of bleed.
Angiography
- Performed when active bleeding that precludes colonoscopy occurs and after colonoscopy has failed to identify a bleeding site.
- Selective mesenteric angiography can detect bleeding at a rate of more than 0.5 mL/min (experimental).
- Diverticula, angiodysplasia, and intestinal varices can be visualised by angiography.
- Invasive (2-11% complication rate)
- If mesenteric angiography is performed at the time of active bleeding, extravasation of contrast media is visualised.
- Once the bleeding point is identified, angiography offers potential treatment options, such as selective vasopressin drip and embolisation.
- Potential to identify causal pathology.
CT angiography
- Helical CT scanning of the abdomen and pelvis can be used when a routine workup fails to determine the cause of active GI bleeding.
- Multiple criteria, including vascular extravasation of the contrast medium, contrast enhancement of the bowel wall, thickening of the bowel wall, spontaneous hyperdensity of the peribowel fat, and vascular dilatations, are used to establish the bleeding site with helical CT scans.
- The presence of diverticula alone is not enough to define the bleeding site.
Treatment
Therapeutic strategies for acute LGIH are based on both the bleed location (or suspected location) and the rate of bleeding.
• More effective therapy of acute LGIH will rely on improved accuracy of localisation of the bleed origin.
• There are three main options available for treatment of
acute LGIH;
• colonoscopy,
• angiography and
• surgery.
• While colonoscopic therapy tends to be the first therapeutic option explored for acute LGIH, surgery remains the mainstay treatment option
Colonoscopic treatment
Therapeutic options offered by colonoscopy include • mechanical devices, • injection therapy, • thermal methods, • snares and polypectomy, • laser therapy and • argon plasma coagulation.
Colonoscopic coagulation is preferred in angiodysplasia because angiography is ineffective due to the capillary and venous bleeding while surgery is associated with high mortality and morbidity.
colonoscopic coagulation is not usually appropriate in patients with diverticulosis because of the severity and location of the bleeding site
Angiographic treatment
Angiography offers two main therapeutic options for the acute LGIH patient; vasopressin and embolisation.
• Vasopressin is a pituitary hormone and following selective intra-arterial infusion into the mesenteric artery, causes vasoconstriction and contraction of the smooth muscle of the blood vessels and colon wall.
Embolisation therapy aims to reduce arterial pressure while maintaining sufficient blood supply via collaterals to maintain viability.
• Embolisation has a high success rate (90% to 100%) and a re-bleed rate of virtually 0%
Surgical treatment
Surgery is generally the option for the management of massive or recurrent LGIH.
- When the bleeding site is localised, the usefulness of segmental resection is well recognised, however, there are still many patients in whom ‘blind’ surgery is the only option
- Up to 25% of acute LGIH patients will undergo surgery without pre- surgical localisation of the bleeding site
- Emergency surgery is required in 10% to 25% of patients presenting with acute LGIH
- more accurate localisation of the bleeding site has reduced mortality rate associated with surgery to 13% (from 28-47%)
- Segmental resection, subtotal colectomy
