Colorectal Surgery Flashcards
What is the investigation of choice for stable and unstable patients having PR bleeds?
Unstable: CT angio
Stable: Sigmoidoscopy or colonoscopy
When should admission be considered in patients with PR bleeds?
- > 60 years
- Haemodynamically unstable / profuse PR bleed
- On aspirin or NSAID
- Significant co-morbidity
What are the indications for surgery in patients presenting with PR bleeding?
- > 60 years
- Continued bleeding despite endoscopic intervention
- Recurrent bleeding
- Known cardiovascular disease with poor response to hypotension
What is the Hinchey classification and how would each classification be managed?
Classification of diverticulitis
1 - Abscess peri/para colic
2 - Abscess pelvic
3 - Peritonitis purulent
4 - Peritonitis faecal (fistula)
Mx:
1- Conservative with Abx
2/3 - Admission + IV Abx + ?percutaneous drainage of abscess
3/4 - percutaneous drainage OR surgery (sigmoidectomy with anastomosis (elective) or mucus fistula (emergency)
What are the macroscopic changes and gross features seen in UC and Crohn’s and what is their depth of disease?
UC:
- Pesudopolyps
- Extensive ulcerations
- Superficial inflammation
Crohn’s:
- Cobblestone appearance
- Thickened bowel wall
- Transmural inflammation
- Patchy skip lesions
What are specific histological findings associated with UC and Crohn’s?
Crohn’s: Granulomas
UC: Crypt abscesses and inflammatory cells in lamina propria
When is surgery indicated in patients with IBD?
- Refractory disease (not responding to medical treatment)
- Intestinal obstruction (i.e. due to strictures)
- Toxic megacolon
- Abscesses / Fistulas / Perforation / Haemorrhage / Cancer
What are the extra intestinal manifestations of IBD?
A PIE SAC
A PIE SAC
- Aphthous ulcers
- Pyoderma gangreosum
- Iritis
- Erythema nodosum
- Sclerosing cholangitis (more associated with UC)
- Arthritis
- Clubbing
What is the most common extra intestinal manifestation in UC and Crohn’s?
Arthritis
What 2 extra intestinal manifestations are more associated with Crohn’s than with UC?
Episcleritis and Gallstones
What surgical approach would you take in a young patient when surgically managing their UC?
- Resection of large bowel and rectum
- Formation of ileo-anal pouch to avoid use of stoma
What surgery would you perform on a patient with IBD, whose disease is confined to the large bowel excluding the rectum?
Colectomy with ileo-rectal anastomosis
How is follow up for colonic polyps determined?
Split into Low, Moderate and High risk groups
Low Risk: 1 or 2 adenomas <1cm - NO F/U or rpt colonoscopy at 5 years
Moderate Risk: 3 or 4 adenomas <1cm OR 1 adenoma >1cm - Rescope at 3 years
High Risk: >5 small adenomas OR >3 adenomas with 1 >1cm - Rescope in 1 year
What is the difference between an oncogene and proto-oncogene?
Proto-oncogene is part of our normal genes. It causes enhanced cell proliferation
Oncogene is the result of a mutation or over expression of a proto-oncogene leading to cancer.
What is Familial adenomatous polyposis (FAP) ?
Autosomal dominant condition characterised by loss of APC tumour suppressor gene
Causes development of hundreds of tubular adenomas with 100% risk of cancer by age 40
What are the different classifications of polyps?
Non-neoplastic:
- Hamartomas
- Metaplastic
Inflammatory:
- Psuedopolyps
- UC
Neoplastic:
- Villous (40%)
- Tubulovillous (20%)
- Tubular (5%)
At what age does someone with FAP have their first colonoscopy and when are they recommended to have a prophylactic panproctocolectomy?
Colonoscopy: 15 years old
Colectomy: 25 years old
As there is a 100% risk of cancer by age 40 in pts with FAP
What is the most common site for an extracolonic cancerous polyp in patients with FAP?
Duodenal polyp
What type of polyp is Peutz Jeghers syndrome associated with?
Hamartomas
What are the 3 main cancers associated with HNPCC (Lynch syndrome)?
Colorectal ca: 30 - 70%
Endometrial ca: 30 - 70%
Gastric ca: 5 - 10%
What difference in presentation would you find between juvenile polyps and meckels diverticulum?
Juvenile polyp: minor, painless bright red rectal bleed with NO change in bowel habit
Meckel’s diverticulum: Mixed bleeding (Rt sided bleeding AND altered bowel habit)
What is Gardner syndrome?
When a patient with FAP develops extra colonic manifestations such as Desmoid tumours and Mandibular osteomas, extra teeth
Issue with APC gene
What is the national screening programme for colon cancer?
60 - 69 years (M+F): colonoscopy every 2 years
> 70 years: colonoscopy every 1 year
What is the Dukes classification system?
Used to stage colon cancers
A: invasion of ca limited to mucosa\
B1: extends into muscular propria but does not penetrate through
B2: Penetrates through muscle layer WITHOUT LN involvement
C1: extends into but does not penetrate the muscle layer. LNs INVOLVED
C2: Penetrates through the muscle layer WITH LN involvement
D: distance mets (e.g. lung, liver, bone, skin etc.)
Is radiotherapy used in right sided colonic cancers?
No
Poorly tolerated and never used as 1st line
Which chemotherapy drug is most often used in treatment of colonic cancer?
Oxaliplatin
What is excised in a subtotal colectomy?
Entire large bowel up until the sigmoid. Usually done in UC
Sigmoid and rectum left in situ and likely anastomosed with small bowel.
What is excised in a right hemicolectomy?
Excision of caecum and ascending colon until proximal 1/3 of transverse colon
What is excised in an abdominal perineal resection?
Lower half of descending colon, sigmoid colon and entire rectum and anus
What are the cancer margins of the anus and rectum that determine the surgical management?
Cancer 6cm away from anal verge: Low anterior resection
Cancer <6cm away from anal verge: Abdomino-perineal resection
How are squamous cell carcinomas of the anus categorised for treatment?
- Competent anal sphincter: Chemoradiotherapy. Decision for surgery made on basis on anal function and survival
- Incompetent anal sphincter:
- Lower anterior resection: 6cm proximal
- Abdmino-perineal resection: <6cm from anal verge
What would be the first line treatment for anal cancer with no metastatic disease?
Radical chemoradiotherapy
What investigation needs to be done in any patient with an obstructing rectal carcinoma prior to any definitive surgical management?
MRI
Patients will often have a loop colostomy done until the rectal ca is investigated further by MRI
In a patient with a non-obstructing rectal ca at 5cm with tethering to the prostate gland, what is seen as an unsafe margin and how will this effect management?
Tethering to the prostate is an unsafe margin for resection.
Rx: Long course chemoradiotherapy
What are the 3 most common sites for haemorrhoids?
3, 7 and 11 o’clock positions
What is the triad for chronic fissures and how long must they be present for to be categorised as chronic?
> 6 weeks
Triad:
- Ulcer
- Sentinel pile
- Enlarged anal papillae
How are haemorrhoids graded?
Grade 1: prominent vasculature with engorgement but no prolapse. Asymptomatic (conservative Rx)
Grade 2: Prolapse WITH straining but reduces spontaneously
Grade 3: Prolapse beyond Dentate line and needs to be reduced manually (itching and swelling)
Grade 4: Prolapsed and can NOT be reduced (Rx: Haemorrhoidectomy)
What is the management of anal fissures?
- Stool softeners
- Topical diltiazem (GTN)
- Botox (if above fails)
- If fails, males should have lateral internal sphincterectomy
What 2 pathogens are associated with anal-rectal abscesses?
E.coli and Staph aureus
What is the most common anal neoplasm?
SCC
What is the most common neoplasm in the rectum?
Adenocarcinoma
How do you investigate rectal prolapse?
- Colonoscopy
- Proctogram
- EUA
What is DeLormes procedure and when is it indicated?
DeLormes procedure:
- Excises mucosa from muscular gut tube
- Interrupted sutures are used to plicate muscular gut wall and reduce prolapse
Used in IMMUNOCOMPROMISED PTS OR HIGH CO-MORBID with EXTERNAL PROLAPSE
High recurrence rate
What is the ideal surgical management of rectal prolapse?
Rectoplexy
Abdominal procedure in which rectum is elevated and supported at level of sacral promontory. A mesh is sutured to the anterior rectum to prevent recurrence of prolapse
How should a pilonidal abscess be treated in the short and long term?
Short term: I+D of abscess
Long-term: if recurring abscesses, plan for excision of sinus (not to be done if there is acute inflammation)
What is Karydakis procedure?
Surgical management of pilonidal sinus
Involved wide excision of natal cleft causing recontouring of the surface once the wound is closed (avoids shearing forces that break hairs off in the first place)
When a lesion is found to be intersphincteric, what is its position relative to the puborectalis?
Lesion would be inferior to Puborectalis (Int. anal sphincter muscle)
If a fistula is transsphincteric, what is it’s location in relation to the puborectalis muscle (Int anal sphincter)?
The fistula penetrates through the puborectalis which is defined as trans-sphincteric
How is a trans-sphincter fistula managed?
Seton insertion
Laying open the tract in a transphincter fistula would cause damage to the pubic rectalis leading to faecal incontinence
How is an inter-sphincter fistula managed surgically?
Laying open the fistula tract
What are papilliferous lesions around the anus a sign of?
Anal carcinoma
What are the biliary effects of a duodenal carcinoma and what condition are duodenal carcinomas associated with?
Associated with FAP
Duodenal carcinomas causes mechanical obstruction of the biliary tree leading to an obstructive jaundice picture
What is Goodsall’s rule?
- Fistula with the external opening anterior to an imaginary transverse line across the anus has its internal opening at the same radial position
- External opening posterior to this line, the internal opening is in the midline posteriorly with a horse-shoe track
The line is an imaginary transverse line that divides the anus to anterior (towards scrotum in men) and posterior (towards coccyx)
