GI Surgery - GI Vasculature and Rectal Bleeding Flashcards
Superior Mesenteric Artery supplies…
Jejunum
Transverse colon
Inferior Mesenteric Artery supplies…
Descending colon
Rectum
Superior Mesenteric Artery –> ischaemia
“Acute mesenteric ischaemia”
Diffuse mesenteric atherosclerosis
“Chronic mesenteric ischaemia”
Inferior Mesenteric Artery –> ischaemia
Ischaemic Colitis (AKA chronic colonic ischaemia)
Acute mesenteric ischaemia
Clinical presentation, Ix, Rx
Clinical Triad:
Acute severe abdominal pain
Abdominal exam normal
Hypovolaemic shock
Ix:
Raised WCC
Metabolic acidosis
AXR “gasless abdomen”
Rx:
Manage peritonitis
Remove dead bowel
Ischaemic colitis spectrum
Mild ischaemia –> gangrenous colitis
Ischaemic colitis
Presentation, Ix
Presentation:
LLQ abdominal pain
Bloody diarrhoea
Ix:
Colonoscopy + Biopsy (gold standard)
Barium enema: “thumb printing”
Chronic mesenteric ischaemia
Presentation
AKA intestinal angina
Colicky post-prandial pain Wt loss (by eating less) Upper abdominal bruit
History of Vascular disease - 95% have diffuse atherosclerosis throughout gut arteries
Rare
A 65-year-old man presents with a 5 hour history of acute, severe pain in the centre of his abdomen. He had stopped taking his amiodarone for a “heart condition” a month ago, saying that he no longer needed it. Abdominal examination shows a rigid abdomen. His blood pressure is 76/40 and HR is 128 bpm. Blood tests show a raised WCC, and his abdominal X-ray shows a gasless abdomen. Select the likely diagnosis:
Ischaemic colitis Toxic Megacolon Acute mesenteric ischaemia Appendicitis Small bowel obstruction
Acute mesenteric ischaemia
Acute severe pain Centre Heart condition Rigid abdomen Raised wcc gasless abdomen
An 85-year-old lady presents with left-sided lower abdominal pain and bloody diarrhoea. She has noticed blood mixed in with stool, but not in the pan/toilet paper. A recent ECHO showed her Left Ventricular Ejection Fraction stands at 35%. Her blood pressure is 100/80, HR is 80 bpm. Her abdomen is soft and non-tender. She appears systemically well. Select the likely diagnosis:
Diverticular disease Ulcerative colitis Colon cancer Ischaemic colitis Rectal varices
Ischaemic Colitis
LL abdo pain Bloody diarrhoea Mixed in LVEJ at 35% systemically unwell
An obese 50-year old man presents with colicky central abdominal pain 5 minutes after eating food, particularly heavy meals. This pain never occurs at rest, and tends to resolve itself after 15 minutes. He has recently noticed 5kg weight loss, but has no fatigue. He has a family history of ischaemic heart disease, and himself has stable angina. His GP has tried “Triple Therapy” to no effect. Select the likely diagnosis:
Chronic mesenteric ischaemia Peptic Ulcer Disease Ischaemic Colitis Gallstones Gastric carcinoma
Chronic mesenteric ischaemia
5 mins after eating food never occurs at rest resolves itself wt loss no fatigue IHD stable angina no effect
Sources of GIT blood
Upper GI:
Peptic ulcer
Oesophageal Varices
Mallory-Weiss
Colonic: Diverticular disease Ischaemic Colitis Infectious Colitis IBD
Anorectal: Haemorrhoids Fissures Cancer Trauma
Rectal Bleeding DDx
Blood mixed with stool:
Painful - Colitis
Painless - Colon tumour; Colitis
Blood streaked in stool:
Painful - Anal tumour
Painless - Rectal tumour
Blood in the pan (separate):
Painful - Colitis
Painless - Haemorrhoids; Diverticular Disease; Colitis (+mucus)
Blood on the paper:
Painful - Anal fissure
Painless - Haemorrhoids
Dentate/Pectinate line
Line that divides bottom third/top two thirds of anal canal. Separates somatic (painful) and visceral (painless) innervation.
Haemorrhoids
Pathogenesis/Rx/Positions
Disrupted and dilated anal cushions which are prone to rupture.
11/3/7 o’clock - 3 anal cushions
Pathogenesis:
- Gravity/Increased anal tone/Straining
- Anal cushions become bulky and loose
- Stools cause rupture
Rx:
Excisional haemorrhoidectomy
Stapled haemorrhoidopexy
Haemorrhoids
Classification
1st Degree:
No prolapse; just prominent blood vessels.
2nd Degree: Prolapse upon bearing down but spontaneously reduced.
3rd Degree: Prolapse upon bearing down and requires manual reduction.
4th Degree: Prolapsed and cannot be manually reduced.
Internal vs External Haemorrhoids
Division via Dentate/Pectinate line
Infectious Colitis Causes
CHESS
Campylobacter jejunii Haemorrhagic E. coli Entamoeba histolytica Shigella Salmonella
C. Difficile
Complications and Rx
Typically folowing a hospital stay or recurrent antibiotic use
Complications: Pseudomembranous colitis Toxic Megacolon (Surgical Emergency) Bowel Perforation (Surgical Emergency)
Rx:
Metronidazole (mild/moderate)
Vancomycin (severe)
Anal Fissure
Presentation and Rx
Painful tear in the squamous lining of the lower anal canal.
Mostly due to hard faeces - secondary to low fibre diet.
Rx:
Increase fibre and fluid intake.
Anal Fistulae
pathogenesis
A track communicates between skin and the anal canal
Pathogenesis:
Blockage of deep glands
Abscess formation
Progression to fistula
Does not present with PR bleeding.
An 18-year old student presents to his GP worried about pain and blood on toilet paper after passing stool. Typically, he says, he also notices a couple of drops of bright red blood in the pan, but none mixed in the stool. The pain is sharp, made worse when wiping and resolves itself within seconds. He tends to pass hard stools infrequently (once per week), which is less often than normal since he moved to halls and started living off Deliveroo meals and pot noodle. What is the likely diagnosis?
Haemorrhoids Anal fissure Anal fistula Rectal tumour Infectious colitis
Anal fissure
Pain Blood on toilet paper Bright red blood in the pan Sharp When wiping Hard stools infrequently Deliveroo meals and pot noodles
A 50-year-old man presents with painless PR bleeding. Blood is seen coating the stool, and in the pan. He reports feeling constipated for the past 2 weeks, leading to increased straining when defecating. He has no sensation of tenesmus or discomfort on sitting. On DRE, no masses are palpable. Proctoscopy, however, shows two spherical masses. Select the likely diagnosis:
Anal Abscess External haemorrhoids Rectal tumour Internal haemorrhoids Anal Fissure
Internal haemorrhoids
Painless PR bleeding Coating the stool Pan Constipated Straining No masses Proctoscopy - two spherical masses
A 41-year-old woman presents with a 5-day history of painful PR bleeding, which coats the stool and pan, and is accompanied with great discomfort on sitting. She reports no tenesmus, weight loss or change in bowel habit. She takes ferrous sulphate tablets for iron deficiency anaemia. O/E: two non-reducible masses are visible at 3 and 7 o’clock outside the anus, which are exquisitely tender to touch. They are not reducible. Select the likely type of haemorrhoid:
2nd degree, internal 3rd degree, internal 3rd degree, external 4th degree, internal 4th degree, external
4th Degree External
Painful PR bleeding Stool and pan Discomfort on sitting Ferrous sulphate tablets Two non reducible masses at 3/7 Exquisitely tender
An 11-year-old boy presents with 6 days of bloody, loose stools and cramping abdominal pain following a dodgy school lunch. The blood is mixed in with the stool, which is also coated in mucus. Select the likely causative organism:
E. coli Salmonella Vibrio cholerae Giardia lamblia Campylobacter jejunii
Camplyobacter jejunii
Bloody loose stools
Cramping abdominal pain
Dodgy school lunch
Mixed in + mucus
A UN aid worker presents to A&E with bloody diarrhoea and cramping abdominal pain upon returning from a project in the Ivory Coast. She reports the blood is mixed in with the stool, which is loose and watery. Select the likely causative organism:
Entamoeba histolytica C. difficile E. coli Serratia marcascens Cholera vibrium
Entamoeba histolytica
UN Aid worker Cramping abdo pain Ivory coast Mixed in Loose and watery
