Colorectal Surgery Flashcards
All different types of stomas:
- gastrostomy
- loop jejunostomy
- percutaneous jejunostomy
- loop ileostomy
- end ileostomy
- end colostomy
- caecostomy
- mucous fistula
Use of gastrostomy:
- gastric decompression or fixation
- feeding
Common site of gastrostomy:
epigastrium
Use of loop jejunostomy:
- not used much as very high output
- following emergency laparotomy with planned early closure
Common site of loop jejunostomy:
any location according to need
Use of percutaneous jejunostomy:
for feeding purposes and site in proximal bowel
Location of percutaneous jejunostomy:
left upper quadrant
Use of loop ileostomy:
- defunctioning colon e.g. following rectal cancer surgery
- does not decompress colon (if ileocaecal valve competent)
Location of loop ileostomy:
right iliac fossa
Use of end ileostomy:
- usually after complete excision of colon or where ileocolic anastomosis not planned
- to defunction colon but reversal more difficult
Location of end ileostomy:
right iliac fossa
Use of end colostomy:
- colon diverted or resected
- anastomosis not primarily achievable or desirable
Location of end colostomy:
left or right iliac fossa
Use of loop colostomy:
- defunction a distal segment of colon
- both lumens present so distal lumen acts as vent
Location of loop colostomy:
any region depending on colonic segment used
Use of caecostomy:
stoma of last resort where loop colostomy not possible
Location of caecostomy:
right iliac fossa
Mucous fistula use:
- decompress distal segment of bowel following colonic division or resection
- where closure of distal resection margin not safe or achievable
Location of mucous fistula:
any region of abdomen
What are the borders of anal cancer?
- anorectal junction
- anal margin (area of pigmented skin around anal orifice)
What type of cancer are most anal cancers?
80% squamous cell carcinoma
Type of anal cancers:
- squamous cell
- melanomas
- lymphomas
- adenocarcinomas
Which lymph nodes do anal cancers spread to?
- anal margin tumours - inguinal lymph nodes
- more proximal tumours - pelvic lymph nodes
In which people are anal cancers more common?
- mwhswm - HPV
- females (1:2 ratio)
- older
Risk factors of anal cancer:
- HPV infection causes 80-85% of SCCs of anus
- anal intercourse
- mwhswm
- HIV or taking immunosuppressive medication
- women with Hx of cervical cancer or cervical intraepithelial neoplasia
- smoking
Symptoms of anal cancer:
- perianal pain
- bleeding
- palpable lesion
- faecal incontinence
- neglected tumour in female may present with rectovaginal fistula
Investigations used for anal cancer:
- T stage assessment: examination, anoscopic examination with biopsy and palpation of inguinal nodes
- imaging: CT, MRI, endo-anal US, PET
- test patients with HIV
Staging of anal cancer:
Tx - primary tumour cannot be assessed T0 - no evidence of primary tumour Tis - carcinoma in situ T1 - tumour <=2cm in greatest dimension T2 - tumour 2-5cm T3 - >= 5cm in greatest dimension T4 - any size but invades adjacent organs (vagina, urethra, bladder) rectal wall perirectal skin, subcutaneous tissue, sphincter NOT classified as T4
What is an anal fissure and when is it chronic vs acute?
- longitudinal or elliptical tear of squamous lining
- acute <6 weeks
Risk factors for anal fissures:
- constipation
- IBD
- STI e.g. HIV, syphilis, herpes
Features of anal fissures:
- painful, bright red, rectal bleeding
- 90% posterior midline (other locations in e.g. Crohn’s)
Management acute anal fissure <1 week:
- soften stool: dietary advice, bulk forming laxatives (lactulose if not tolerated)
- lubricants e.g. petroleum jelly before defecation
- topical anaesthetics
- analgesia
Management chronic anal fissure:
- acute techniques
- topical GTN first line
- if not effective after 8 weeks - consider surgery (sphincterotomy)
- botulinum toxin
Locations of colorectal cancers in order of prevalence:
- rectal
- sigmoid
- descending colon
- transverse colon
- ascending colon and caecum
Type of resection and anastomosis used in caecal, ascending or proximal transverse colon cancer:
- right hemicolectomy
- ileo-colic
Type of resection and anastomosis used in distal transverse and descending colon cancer:
- left hemicolectomy
- colo-colon
Type of resection and anastomosis used in sigmoid colon cancer:
- high anterior resection
- colo-rectal
Type of resection and anastomosis used in upper rectum cancer:
- anterior resection
- colo-rectal
Type of resection and anastomosis used in low rectum cancer:
- anterior resection
- colo-rectal (defunctioning stoma)
Type of resection and anastomosis used in anal verge:
- abdomino-perineal excision or rectum
- no anastomosis
Management when colonic cancer presents with obstructing lesion:
- stent or resect
- following resection, patients with risk factors for recurrence are offered chemotherapy, combination of 5FU and oxaliplatin common
How are rectal cancers resected?
- anterior resection or abdomen-preineal excision of rectum (APER)
- 2cm distal clearance margin
- also mesolectal fat and lypmh nodes
- can irradiate because exztraperitoneal unlike colonic
- obstructing rectal cancer: defunctioning loop colostomy instead because of high rate of anastomotic leak
Management of emergency perforation of bowel:
- increased risk of anastomosis especially colon-colon
- end colostomy safer and can be reversed later
Hartmans procedure:
- sigmoid resection
- end colostomy
Urgent referral guidelines for colorectal cancer (within 2 weeks):
- patients >=40yo with unexplained weight loss AND abdominal pain
- patients >=50yo with unexplained rectal bleeding
- patients >=60yo with iron deficiency anaemia OR change in bowel habit
- test shows occult blood in faeces
- consider if: anal mass/ulceration, 50yo with rectal bleeding AND pain, change in bowel habit, weight loss, iron deficiency anaemia
Who should be offered faecal occult blood testing?
- patients >=50yo with unexplained abdominal pain OR blood loss
- patients <60yo with changes in bowel habit OR iron deficiency anaemia
- patients >=60yo with anaemia or absence of iron def
When is CRC screening carried out?
every 2 years to all men and women 60-74 years (request over 74yo)
How is CRC screening carried out?
- faecal immunochemical test through post
- faecal occult blood test uses antibodies which recognises human haemoglobin
- quantifies amount of human blood in single stool sample
- abnormal results offered colonoscopy
- also flexible sigmoidoscopy screening
Why is flexible sigmoidoscopy used in CRC screening?
- to detect and treat polyps and reduce further risk
- offered to 55yo
Usual site of diverticular disease:
between taenia coli where vessels pierce muscle to supply mucosa
-rectum spared
Diagnosis of diverticular disease:
- colonoscopy
- CT cologram
- barium enema
- critically unwell: plain abdominal films, erect CXR for perforation, abdominal CT with oral and IV contrast
Hinchey classification of diverticular disease severity:
I - para-colonic abscess
II - pelvic abscess
III - purulent peritonitis
IV - faecal peritonitis
Treatment of diverticular disease:
- dietary fibre
- mild: Abx
- abscess can be drained
- Hinchey IV perforations - resection and stoma