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Y5 - Surgery > Colorectal > Flashcards

Flashcards in Colorectal Deck (37):
1

Types of colonic polyps

Non-neoplastic
- Hyperplastic
- Inflammatory/pseudopolyps
- Hamartoma/congenital/juvenile

Neoplastic
- Tubular (90%), tubulovillous (10%), villous (1%)
- Familial, sporadic
- Adenocarcinoma

2

3 features of a polyp that increase risk of malignancy

1. Size: >2cm
2. Type: villous
3. Degree of dysplasia: severe

3

Familial Adenomatous Polyposis (FAP)

- Most common polyposis syndrome
- Autosomal dominant condition
- Characterised by 100's-1000's of adenomas in the colorectal mucosa by 20-30yrs old
- Lifetime risk of CRC = 100%
- Also at risk of other tumours - upper GIT, CNS
- Patho: defect in APC tumour suppressor gene

4

Hereditary Nonpolyposis Colorectal Cancer (HNPCC) aka Lynch syndrome

- Autosomal dominant disorder in which colon cancers arise in discrete adenomas in proximal colon
- Germline mutation in one of several genes involved in the mismatch repair system, most commonly hMSH2 or hMLH1
- Only 1 of 2 copies of the gene is defective -> individuals are at risk of inactivation of the remaining good gene copy -> CRC
- Amsterdam criteria
- Colonoscopy screening for high-risk CRC individuals every 1-2 years
- Starting at age 25 or 5 years before the earliest diagnosis in the family

5

Colorectal Cancer - risk factors

Non-modifiable:
- Age >50 (average 72), sex (m), previous polyps or previous CRC, first degree relatives with a hx of bowel cancer, hereditary syndromes - FAP, HNPCC, MYH, hx IBD

Modifiable:
- Smoking, obesity, high meat/fat diet, low fibre

6

Colorectal Cancer - symptoms

- PR bleeding
- Change in bowel habit - constipation alternating with increased frequency
- Tenesmus
- Anal symptoms - soreness, discomfort, lumps, pain
- Abdo pain - left sided colicky abdominal pain
- Fatigue, weight loss
- Iron deficiency symptoms - fatigue, dyspnoea, chest pain

7

Colorectal Cancer - Examination

General - pale, fatigued, cachectic
Vitals - tachy (anaemic)
- Hands - koilonychia, pallor of creases
- Face - conjunctival pallor, angular stomatitis, glossitis
- Neck - palpate Virchow node (left supraclavicular)

Abdomen
- Inspection - scars, masses
- Palpation - tenderness, masses, hepatomegaly
- Auscultate
- Percussion
DRE

Other systems - CV, Resp

8

Colorectal Cancer - Investigations

Bloods
- FBC - Hb, WBC
- Iron studies
- LFT's, UEC
- CEA

Imaging
- Colonoscopy + biopsy
- CT - chest, abdo, pelvis
*Rectal cancer - endoanal ultrasound, MRI

9

Colorectal Cancer - Screening

General Population
- Faecal occult blood testing (iFOBT) - every 2 years for adults aged 50-74yrs
- 2 stool samples
- If 1 is positive -> GP -> colonoscopy

Family Hx of CRC
- For those with a 1st degree relative diagnosed with CRC at 55yrs or older -> consider FOBT every 2 yrs from 45yrs old
- People with 1st degree relative diagnosed with CRC <55yrs of age -> FOBT should be performed every 2 yrs from 40-50, and colonoscopy every 5 yrs from 50-74, consider low dose aspirin (100mg daily)

High Risk Familial Syndromes
- FAP - start surveillance at 10-15yrs old - colonoscopy, once adenoma has been found, need colonoscopy every 12 months

10

Pilonidal Disease

- Pilonidal disease results from loose hairs in the gluteal cleft skin that causes a foreign body reaction -> midline pits and occasionally secondary infection
- This may result in abscess, cyst or sinus tract that grows under the skin of the gluteal cleft
- Most common between 15-24yrs
- 3x more common in men

11

- TNM

Stage 0: carcinoma in situ - tumour contained within the mucosa (Tis, N0, M0)
Stage 1: tumour invades submucosa or muscularis propria, no lymph node involvement, no mets (T1 or T2, N0, M0)
Stage 2: tumour invades muscularis propria into submucosa, tumour perforates the visceral peritoneum or directly invades other organs or structures (T3, N0, M0)
Stage 3: any degree of bowel wall perforation with regional lymph node mets (T, N1, N2, M0)
Stage 4: any invasion of the bowel wall +/- lymph node mets, but with evidence of distant metastasis (any T, any N, M1)

12

- Staging Duke's Criteria

Stage A: lesions limited to the bowel wall
Stage B: extending through the wall
Stage C: extending to nodal or regional mets
Stage D: extending to distant mets

13

Colorectal Cancer - Surgical Options

Right Hemicolectomy/Extended Right Hemicolectomy
- Surgical approach for caecal or ascending tumours
- The ileocolic, right colic and right branch of middle colic vessels are divided and removed
- Extended - performed for transverse colon cancers

Left Hemicolectomy
- Surgical approach for descending colon cancer
- Left branch of middle colic vessels, IMV and left colic vessels are removed

Sigmoidcolectomy
- Surgical approach for sigmoid colon tumours

Low Anterior Resection (LAR)
- Surgical approach for high rectal tumours (>5cm from anus)
- Leaves rectal sphincter intact and functioning

Abdominoperineal Resection (APR)
- Surgical approach for low rectal tumours (<5cm from anus)
- Involves excision of distal colon, rectum and anal sphincters -> permanent colostomy

Hartmann’s Procedure
- Used in emergency bowel surgery (bowel obstruction or perforation)
- Involves a complete resection of the recto-sigmoid colon with the formation of an end-colostomy and the closure of the rectal stump

14

Haemorrhoids - definition/pathophys

- Haemorrhoid = abnormal swelling or enlargement of anal vascular cushions

- The anal vascular cushions are specialised vascular cushions that are located in the submucosal space in the anal canal
- They are a normal part of human anatomy
- Over time, as supportive CT weakens, the vascular cushions enlarge and become symptomatic -> haemorrhoids

15

Haemorrhoids - Types

Internal
- Located above the dentate line, covered by mucosa, do not have sensory innervations

External
- Located below the dentate line, covered by squamous epithelium and have sensory innervation

16

Haemorrhoids - Classification of internal

1st degree: small in size, bleed
2nd degree: medium in size, prolapse under pressure, return spontaneously
3rd degree: large in size, permanent prolapse, can be reduced manually
4th degree: large size, prolapse is irreducible

17

Haemorrhoids - Risk factors

- Increasing age
- Increased IAP - pregnancy, ascites, chronic cough, straining
- Heavy lifting, prolonged sitting
- Anal intercourse
- High fat, low fibre diet

18

Haemorrhoids - clinical features

- Painless bright red bleeding, after defecation and often seen on toilet paper, or covering the pan (blood is on the surface of stool, not mixed in)
- Anorectal pain, lump at external anus
- Anorectal itching
- Large prolapsed haemorrhoids can thrombose -> incredibly painful

19

Haemorrhoids - investigations

Bloods
- FBC

Imaging
- Anoscopy
- Colonoscopy

20

Haemorrhoids - management

- Lifestyle - high fibre diet, increased fluid intake, avoid straining, psyllium
- Pain and itching relief - topical anaesthetics - benzocaine, lidocaine

Procedures to Stop Bleeding
External haemorrhoids:
- External haemorrhoid excision

Internal haemorrhoids
- Rubber band ligation
- Internal haemorrhoid surgical excision

21

Anal Fissure - definition

- Superficial tear along the anal sphincter (longitudinal), extending from just below the dentate line to the anal margin
- Usually occurs in the midline posteriorly

22

Anal Fissure - causes

Main cause
- Constipation and trauma to the anal canal from a hard stool

Other:
- Straining
- IBD

23

Anal Fissure - clinical features

- Severe anal pain during and immediately after defecation
- PR bleeding
- Pain is so intense that the patient is afraid of and avoids opening the bowels

24

Anal Fissure - focused examination

- Inspection - while patient is in left lateral position, gently stretch apart the buttocks -> look for the fissure
- If the diagnosis is suspected on history and visual inspection DO NOT DO DRE -> cause severe and unnecessary pain

25

Anal Fissure - management

- Aim: relax the internal sphincter -> relieving pain
- Topical anaesthetic and hydrocortisone ointment
- High fibre diet, laxatives
- Warm salt bath after bowel movements
- GTN ointment

26

Anorectal abscess - definition and types

- Collection of pus in the anal or rectal region
- Most commonly a self-limited process thought to result from obstruction and infection of anal glands located in the crypts along the dentate line

Types: perianal (most common), ischiorectal, intersphincteric, submucosal

27

Anorectal abscess - causes

- Obstruction/infection of anal glands
- Crohn’s disease, trauma, malignancy, radiation exposure

28

Anorectal abscess - clinical features

- Acute pain in the perianal area
- Acutely painful defecation
- Swelling, itching, discharge
- Fever (if severe)

29

Anorectal abscess - focused examination

- Acute pain in the perianal area
- Acutely painful defecation
- Swelling, itching, discharge
- Fever

30

Anorectal abscess - management

Surgical drainage
- Superficial - can be drained using LA
- More extensive infections require GA
- Analgesia
- Sitz baths

31

Anorectal fistula - definition

- Fistula = abnormal communication between 2 epithelial-lined surfaces
- Anorectal fistula = abnormal communication between the anorectum and perineal skin
- Occurs as a complication of an acute or chronic perianal abscess

32

Anorectal fistula - types

Types: classified by their route b/w an internal opening in the anal canal and an external opening on the perianal skin
- Inter-sphincteric (most common)
- Trans-sphincteric
- Supra-sphincteric
- Extra-sphincteric

33

Anorectal fistula - Hx

- Previous episode of perianal abscess
- Hx of anal surgery, anal infections, radiation, trauma, obstetric trauma
- Systemic disease - IBD, immunosuppression

34

Anorectal fistula - clinical features

- Intermittent anal pain, itching
- Bloody, purulent or feculent discharge

35

Anorectal fistula - examination

DRE
- Inspection - external opening visibile
- Palpation - fibrous tract

36

Anorectal fistula - imaging

Visualise tract opening
- Sigmoidoscopy

Visualise remaining part of the tract
- Fistulography
- Endoanal U/S
- MRI

37

Anorectal fistula - Management

Depends on the size/location
- Conservative management
- Glue
- Plugs
- Seton stitch (allows for it to heal, prevents entry but not exit)
- Stoma