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Y5 - Surgery > Colorectal > Flashcards

Flashcards in Colorectal Deck (37)
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1
Q

Types of colonic polyps

A

Non-neoplastic

  • Hyperplastic
  • Inflammatory/pseudopolyps
  • Hamartoma/congenital/juvenile

Neoplastic

  • Tubular (90%), tubulovillous (10%), villous (1%)
  • Familial, sporadic
  • Adenocarcinoma
2
Q

3 features of a polyp that increase risk of malignancy

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

Familial Adenomatous Polyposis (FAP)

A
  • 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
Q

Hereditary Nonpolyposis Colorectal Cancer (HNPCC) aka Lynch syndrome

A
  • 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
Q

Colorectal Cancer - risk factors

A

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
Q

Colorectal Cancer - symptoms

A
  • 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
Q

Colorectal Cancer - Examination

A

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
Q

Colorectal Cancer - Investigations

A

Bloods

  • FBC - Hb, WBC
  • Iron studies
  • LFT’s, UEC
  • CEA

Imaging

  • Colonoscopy + biopsy
  • CT - chest, abdo, pelvis
  • Rectal cancer - endoanal ultrasound, MRI
9
Q

Colorectal Cancer - Screening

A

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
Q

Pilonidal Disease

A
  • 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
Q
  • TNM
A

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
Q
  • Staging Duke’s Criteria
A

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
Q

Colorectal Cancer - Surgical Options

A

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
Q

Haemorrhoids - definition/pathophys

A
  • 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
Q

Haemorrhoids - Types

A

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
Q

Haemorrhoids - Classification of internal

A

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
Q

Haemorrhoids - Risk factors

A
  • Increasing age
  • Increased IAP - pregnancy, ascites, chronic cough, straining
  • Heavy lifting, prolonged sitting
  • Anal intercourse
  • High fat, low fibre diet
18
Q

Haemorrhoids - clinical features

A
  • 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
Q

Haemorrhoids - investigations

A

Bloods
- FBC

Imaging

  • Anoscopy
  • Colonoscopy
20
Q

Haemorrhoids - management

A
  • 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
Q

Anal Fissure - definition

A
  • 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
Q

Anal Fissure - causes

A

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

Other:

  • Straining
  • IBD
23
Q

Anal Fissure - clinical features

A
  • 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
Q

Anal Fissure - focused examination

A
  • 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
Q

Anal Fissure - management

A
  • 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
Q

Anorectal abscess - definition and types

A
  • 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
Q

Anorectal abscess - causes

A
  • Obstruction/infection of anal glands

- Crohn’s disease, trauma, malignancy, radiation exposure

28
Q

Anorectal abscess - clinical features

A
  • Acute pain in the perianal area
  • Acutely painful defecation
  • Swelling, itching, discharge
  • Fever (if severe)
29
Q

Anorectal abscess - focused examination

A
  • Acute pain in the perianal area
  • Acutely painful defecation
  • Swelling, itching, discharge
  • Fever
30
Q

Anorectal abscess - management

A

Surgical drainage

  • Superficial - can be drained using LA
  • More extensive infections require GA
  • Analgesia
  • Sitz baths
31
Q

Anorectal fistula - definition

A
  • 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
Q

Anorectal fistula - types

A

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
Q

Anorectal fistula - Hx

A
  • Previous episode of perianal abscess
  • Hx of anal surgery, anal infections, radiation, trauma, obstetric trauma
  • Systemic disease - IBD, immunosuppression
34
Q

Anorectal fistula - clinical features

A
  • Intermittent anal pain, itching

- Bloody, purulent or feculent discharge

35
Q

Anorectal fistula - examination

A

DRE

  • Inspection - external opening visibile
  • Palpation - fibrous tract
36
Q

Anorectal fistula - imaging

A

Visualise tract opening
- Sigmoidoscopy

Visualise remaining part of the tract

  • Fistulography
  • Endoanal U/S
  • MRI
37
Q

Anorectal fistula - Management

A

Depends on the size/location

  • Conservative management
  • Glue
  • Plugs
  • Seton stitch (allows for it to heal, prevents entry but not exit)
  • Stoma