Colorectal Surgery JC061: Fresh Blood In Stool: Lower GI Bleeding Flashcards
Lower GI bleeding
Bleeding from gut ***distal to Suspensory ligament of Treitz (Duodeno-Jejunal flexure)
- Small bowel, Colon, Rectum, Anus
- trivial to life-threatening blood loss
- hard to differentiate —> haemorrhage from upper GI tract can present with features similar to lower GI bleeding
(Upper GI bleeding: Proximal to Suspensory ligament of Treitz
Small bowel bleeding: Distal to Major duodenal papilla, Proximal to IC valve)
Characteristics of Lower GI bleeding
- Acute / Chronic
- Acute LGIB: bleeding of recent duration, may result in **instability of vital signs, anaemia, need for **transfusion (e.g. **Diverticulum bleeding, **Angiodysplasia)
- Chronic LGIB: passage of blood over a period of several days, slow loss of blood (e.g. tumour) - Overt / Occult
- Massive / Slow
- “Obscure GI bleeding”
Outlet bleeding
Bleeding from Anorectal sources:
- **Fresh blood
- **Separated from stool
- Variable amount, usually small
- ***Anorectal symptoms (e.g. pain in Anal fissure, prolapsed mass in Haemorrhoids)
- Usually no haemodynamic disturbance
- Assessed + Managed as outpatient
Common causes (記: 潰瘍, 發炎, 裂, 痔瘡, 腫瘤, 手術, 流血不止, Diverticulitis, Angiodysplasia):
1. **Haemorrhoids
2. Fissure-in-ano
3. Rectal ulcer (more common in elderly with chronic constipation)
4. **Colorectal neoplasm (esp. recent onset in elderly)
5. ***Proctocolitis
- IBD
- Radiation
- Infection
Acute Lower GI bleeding
- Disease of elderly (∵ mostly due to **Diverticular disease, **Angiodysplasia)
- Annual incidence requiring hospitalisation: 20-27 / 100,000
- ↑ Incidence with advancing age
- 200 fold ↑ in patients in 3rd decade to 9th decade
Management of Acute Lower GI Bleeding
- Resuscitation + Haemodynamic stabilisation
- Venous access
- **IV crystalloid solution —> expand IV volume
- Cross match blood + **Transfusion (if massive bleeding)
- Monitor haemodynamic status
- History, PE, Investigations should not delay resuscitation - Localisation of bleeding site
- Therapeutic intervention
- **Endoscopic
- **Angiographic
- ***Surgery
(Bleeding usually stop spontaneously in 75% patients)
Indications of Transfusion
- Profuse bleeding
- ***Persistent haemodynamic instability despite crystalloid resuscitation
- Symptomatic anaemia
- **AMI / Unstable angina with **low Hb (i.e. Haemodynamically unstable)
***History taking in Lower GI bleeding
- Severity
- Duration
- GI symptoms (abdominal pain / change in bowel habit)
- Anorectal symptoms
- Systemic symptoms
- e.g. Coagulopathy - History of previous bleeding episodes
- Previous investigations
- Significant comorbid conditions (heart / liver diseases)
- Medications (NSAID, anticoagulants, antiplatelets)
- Social history, Family history
P/E of Lower GI Bleeding
- Haemodynamic status
- BP
- Pulse
- RR
- **Urine output
- **CVP - Abdominal examination (usually negative, seldom can feel abdominal mass)
- ***PR examination
- characteristics of blood
- anorectal conditions - ***Proctoscopy
- characteristics of blood
- inflammatory changes in rectum
Investigations / Monitoring of Lower GI bleeding
- Haemodynamic status (TURBO-P)
- BP
- Pulse
- RR
- **Urine output
- **CVP - Blood tests
- Hb, Hct, MCV
- Plt
- LRFT
- **Clotting profile
- **Type + Cross match for transfusion
Localisation of bleeding site
3. **Endoscopy
- Proctoscopy / Sigmoidoscopy —> exclude bleeding from anorectal pathology
- Upper endoscopy —> exclude UGIB (~10% proximal to ligament of Treitz in patients with haematochezia)
- Colonoscopy
- Enteroscopy
- Intraoperative endoscopy
- NG tube? —> bile stained aspiration: bleeding from UGIT excluded
4. **Angiography
5. Radionuclide scan (RBC, sulphur colloid)
6. Other imaging (CT, small bowel contrast)
(failure in localisation 8-12%)
Colonoscopy
- Accurate tool to evaluate lower GI bleeding (75-90% diagnostic yield)
- Early colonoscopy —> ↑ detection of bleeding source + shorter hospital stay
- Low complication rate
-
Therapeutic procedure possible
—> most bleeding from colonic lesions stop spontaneously
—> therapeutic modalities (Sclerotherapy (injection of sclerosants / vasoconstrictors), **Heat probe, Electrocoagulation, **Laser, **Haemoclips, **Argon beam coagulation)
—> effective in Angiodysplasia, Diverticulitis, Proctocolitis - Bowel preparation:
—> ↑ diagnostic yield without ↑ morbidity
—> not feasible in unstable patients
—> balance between accuracy of colonoscopy / tolerance of patients to bowel prep (bleeding might have stopped before bowel prep done)
CT angiography
- Similar accuracy to Scintigraphy
- Quicker + More accurate
- Can be performed prior to Conventional Angiography
Conventional Angiography
- Confirm bleeding + Locate bleeding site
- Selective catheterisation of SMA, IMA, Celiac artery by ***Seldinger technique
- Bleeding 1-1.5 ml/min can be detected
- Positive test: ***Extravasation of contrast into lumen (X presence of lesion)
- 27-67% diagnostic yield
- Complications:
—> ***Contrast allergy
—> Renal failure
—> Bleeding from puncture site
Therapeutic angiography
- ***Embolisation
- risk of bowel ischaemia, infarction - ***Injection of vasopressin (vasoconstrictor)
- cardiac SE
Radionuclide scan
- **Tc-99 labelled Sulphur colloid / **Tagged RBC
- Labelled RBC not cleared rapidly + not taken up by liver / spleen
- ***High sensitivity (80-98%: detects bleeding as slow as 0.1 ml/min)
- No therapeutic value
- Less specific
—> **less able to locate bleeding site (vs Angiography)
—> used as **screening tool to confirm bleeding prior to Angiography for non-life-threatening bleeding
Surgery
- Required in ~15-20% of patients with Acute LGIB
- ***Last resort, usually delayed (∵ bleeding usually not profuse, haemodynamic less affected)
- Indications:
—> **Haemodynamic instability
—> **Transfusion requirement (>=6 units of blood)
—> ***Persistent bleeding
—> Rebleeding within 1 week
With localisation:
- ***Segment resection
Without localisation:
- **Subtotal colectomy if bleeding from colon
- **Intraoperative Colonoscopy / Enteroscopy for localisation
Outcome:
- Segmental resection with localisation:
—> rebleeding: 0-15%
—> mortality: 0-13%
- Blind segmental resection:
—> rebleeding: up to 75% - Subtotal colectomy:
—> mortality: 0-40%
***Common causes of Lower GI bleeding
記: Diverticulosis, Angiodysplasia, Colitis, Tumour, Anorectal, Small bowel
- ***Diverticular disease
- ***Ischaemic colitis (∵ degenerative vessels)
- ***Angiodysplasia (∵ vascular ectasia)
- Colitis
- IBD
- radiation (e.g. treatment for gynaecological tumour, prostate cancer)
- infective - ***Neoplasm
- Post-polypectomy
- ***Anorectal sources
- haemorrhoids
- rectal ulcers
- rectal varices
- fissures - Small bowel sources
- Meckel’s diverticulitis
- Vascular lesions (Angiodysplasia, Haemangioma)
- Small bowel tumours
- Small bowel ulcers (NSAID induced)
- ***Crohn’s disease
- Aortoenteric fistula - Massive bleeding from UGIT
Diverticular disease
- Western: Sigmoid colon
- Asia: ***Ascending colon
Treatment:
- Injection with adrenaline
Angiodysplasia
- ***Ectasia of vessels lying in Submucosa
- Acquired condition associated with degeneration (2/3 >=70yo)
- May be associated with Vascular malformations in other GI tract (**Osler-Weber-Rendu disease (HHT)) and **Aortic stenosis
Features:
- More commonly in **Descending colon (but can occur throughout whole colon)
- Bleeding less severe than Diverticular haemorrhage (but tends to be **intermittent i.e. higher recurrence rate)
- Bleeding stops in 85-90%
- Rebleeding 25-85%
Treatment:
- ***Not necessary for non-bleeding angiodysplasia
- Endoscopic
- Surgery
Colitis
- IBD
- **Crohn’s disease (sometimes significant bleeding)
- **Ulcerative colitis (rectum + diarrhoea) - Infective colitis
- ***Radiation colitis (more common now)
- treatment for gynaecological / prostate cancer - ***Ischaemic colitis
- ∵ atherosclerosis - Idiopathic ulcers
IBD
- ***Bloody diarrhoea
- Not life-threatening
UC:
- Bloody diarrhoea
- Small amount
- 6-10% UC with LGIB enough to necessitate emergency surgery
- **High chance of rebleeding
—> **Surgery recommended
—> Total colectomy in emergency
Crohn’s disease:
- Life-threatening LGIB uncommon
- Usually due to colitis
- **Total colectomy recommended
—> Anastomosis: depend on extent of rectal involvement
- **Segmental small bowel resection (preserve as much as possible) for bleeding from small bowel (localisation of lesion)
Radiation proctocolitis
Features:
1. **Damage of rectal mucosa (∵ long term SE from radiation treatment)
2. Formation of Vascular **telengiectasis
3. Chronic rectal bleeding (1-5% necessitate hospitalisation + transfusion regularly)
Treatment:
1. No cure (∵ damage done, cannot be reversed)
-
**Endoscopic treatment (multiple sessions)
- **Infrared coagulation
- **Argon beam coagulation
- **Laser - ***Formalin: Local application of 4% formalin
- ***Surgery (for uncontrolled bleeding)
- Diversion colostomy
- Proctectomy (high mortality / morbidity)
Anorectal sources
- ~10% LGIB
Causes:
1. Haemorrhoids (∵ faecal impaction —> faecal evacuation)
2. Fissure-in-ano
3. Anal / Rectal ulcer
4. Rectal varices
- associated with portal hypertension
- severe bleeding
- local therapy: ***injection sclerotherapy
- surgery: shunting (for uncontrolled bleeding)
Investigations:
- PR exam
- Proctoscopy
Obscure GI bleeding
Bleeding of unknown origin that persists / recur after a negative initial endoscopy (Colonoscopy / Upper endoscopy)
- ***usually in Small bowel
Treatment:
- Repeat Colonoscopy / Upper endoscopy
—> identified 35% of bleeding lesions in Small bowel
***Bleeding from small bowel
- 5% LGIB
Causes (記: Diverticulosis, Angiodysplasia, Colitis, Tumour, Drug):
1. **Angiodysplasia
2. Jejunoileal diverticula
3. **Meckel’s diverticulum (Ectopic gastric / pancreatic mucosa)
4. **Neoplasm
- GIST (grow towards mucosa causing ulcer —> bleeding)
- Neuroendocrine tumour
- Adenocarcinoma (rare)
5. **Crohn’s enteritis
6. ***Drug related ulcers
7. Infection (TB)
(vs Upper GI bleeding (記: 潰瘍, 發炎, 靜脈曲張, 嘔, 腫瘤))
Diagnosis of Small bowel bleeding
- ***Angiography
- difficult to interpret (SMA? IMA? Celiac artery?) - ***RBC scan
- non-specific - Small bowel enema
- ***CT Enteroclysis
- low yield
- cannot detect vascular lesions -
**Enteroscopy
- Push enteroscopy
- **Single balloon enteroscopy
- **Double balloon enteroscopy
- **Intraoperative
Push enteroscopy
- Upper endoscopy beyond ***DJ flexure
- Paediatric colonscope
- Long endoscope with ***overtube (therapeutic tools to stop bleeding)
- Length of Jejunum examined varies
- Procedures well tolerated with few complications
- Channel for therapeutic measures
- 30% diagnostic yield
Capsule enteroscopy
- Diagnostic capsule that take colour video images
- ***Need bowel preparation
- Signal of its location transmitted + detected by sensor (carried by patient, can be ***ambulatory)
- No additional diagnosis made by push enteroscopy
Double balloon enteroscopy
- Long
- ***Specialised balloons + overtube
—> anchor overtube + advance endoscope (蚯蚓咁郁)
—> to advance scope into more distal part of small bowel - Tip of scope can be smoothly inserted to reach area of diagnosis
- Passes from mouth / anus to completely examine small bowel
- ***Biopsy / Therapeutic procedures can be performed
Intraoperative endoscopy
- In situations where prior localisation cannot be made
- Allows ***complete examination of small bowel
- Higher diagnostic yield
Colonoscopy:
- Foley catheter inserted through appendicotomy / enterotomy
- Bowel preparation by on table antegrade irrigation
- Effluent from anus
Route:
- Trans-anal
- Per-oral
- Through enterotomy
- Laparoscopic assisted
Summary
- Successful management of LGIB requires aggressive resuscitation + localisation of bleeding site
- Surgery indicated in massive + continuous bleeding
—> require good localisation of bleeding site - Bleeding from small bowel is difficult to localise
