Colorectal Surgery Flashcards
Describe the role of screening as applied to colon cancer.
- Quantitative faecal immunochemical test (qFIT)
- Replaced faecal occult blood test (FOBT) in November 2017 in Scotland
- Once off flexible sigmoidoscopy (only age >55 in certain areas of England)
Describe the management of colon cancer.
Pre-op management;
- Colon and rectal cancer treated as 2 separate entities.
- MDT discussion (including anaesthetic and stoma nurse).
- Colon cancer almost always straight to surgery (if no metastases and fit patient).
- MRI important – dictates if use of neoadjuvant therapy is required pre- and/or post-op.
Post-op management;
- Dependent on pathological staging.
- Presence of high-risk pathological features.
- Adjuvant chemotherapy may be required.
- Post-operative complications might hinder or delay adjuvant treatment.
- Surveillance CT CAP, colonoscopy.
- (In NHSG) alternate USS liver + CT CAP every 6 months.
Describe the arterial supply of the colon.
As a general rule…
Ascending colon and proximal 2/3rds of transverse colon –> midgut –> supplied by superior mesenteric artery.
Distal 1/3rd of transverse colon, descending and sigmoid colon –> hindgut –>supplied by inferior mesenteric artery.
Ascending colon: SMA –> ileocolic (–> colic, anterior + posterior cecal) + right colic.
Transverse colon: SMA –> right + middle colic, IMA –> left colic.
Descending colon: IMA –> left colic.
Sigmoid colon: IMA –> sigmoid arteries.
Describe the venous drainage of the colon.
Ascending colon: ileocolic + right colic –> SMV.
Transverse colon: middle colic –> SMV.
Descending colon: left colic –> IMV.
Sigmoid colon: sigmoid veins –> IMV.
Describe the neural supply of the colon.
Midgut-derived structures are supplied by superior mesenteric plexus.
Hindgut-derived structures are supplied by inferior mesenteric plexus.
Parasympathetic - pelvic splanchnic nerves.
Sympathetic - lumbar splanchnic nerves.
Describe the important factors of anorectal continence.
- Anatomy: puborectalis sling, sphincter complex, anal cushions
- Rectal compliance
- Stool consistency
- Central control
- Anorectal sensation
Define screening.
The presumptive identification of unrecognised disease in an apparently healthy, asymptomatic population by means of tests, examinations or other procedures that can be applied rapidly and easily to the target population.
Describe the presentation of CRC.
- Colicky abdominal pain
- Rectal bleeding (consider anorectal pain, colour, mixed in stool)
- Change in bowel habits (diarrhoea, constipation)
- Weight loss
- Tenesmus
- Fatigue
- Vomiting
Describe the protocol for managing patients with rectal bleeding and assessing symptoms.
Low risk features; Transient symptoms (<6 weeks) - Rectal bleeding with anal symptoms - Patient age <40 --> Watch and wait (6 weeks); - Assessment and review - Setting determined locally - Patient agreement required - Appropriate information and counselling --> Review No further symptoms; - Discharge OR Symptoms; - Persist or recur - Deteriorate - Patient will not agree to “watch and wait” --> Visualisation of the large bowel; - Colonoscopy - Flexible/ rigid sigmoidoscopy - CT colonography
High risk features;
- Persistent change in bowel habit (>6 weeks)
- Persistent rectal bleeding without anal symptoms
- Right-sided abdominal mass
- Palpable rectal mass
- Unexplained iron deficiency anaemia
- Patients in whom there is clinical doubt
–> Refer
- E-communication
- Structured proforma
- Decision support
–>
Visualisation of the large bowel (as seen above)
Describe the percentage of tumours found based on location in the GIT.
- Proximal – 43%
- Distal – 30%
- Rectum – 27%
Describe the basic surgical principles of rectal cancer.
- Rectum surrounded by fatty envelope called the mesorectum, which contains all the draining lymph nodes of rectum.
- To reduce local recurrence rate, the rectum and it’s surrounding mesorectum has to be excised en bloc. (TME)
- If mesorectal fascia involved, surgery will be pointless unless tumour is downstaged and circumferential resection margins (CRM) are cleared.
Explain why an MRI is performed pre-operatively in rectal cancer.
- Best imaging modality for looking at CRM.
- Neoadjuvant treatment for circumferential resection margin (CRM) threatened disease, Extramural venous invasion (EMVI), nodal disease, very low rectal cancer, etc.
- Restaging 6-8 weeks later following neoadjuvant treatment.
- Surgery 8-10 weeks after treatment (Total Mesorectal Excision – TME).
Describe the treatment of rectal cancer.
- Surgical vs medical.
- Open vs minimally invasive.
Consider; - Resection
- Restoration intestinal continuity
Faecal diversion: Stoma - Preservation of function
- Palliative if advanced metastatic disease
Describe the complications of surgical management of CRC.
- Bleeding
- Infection (superficial and deep)
- Anastomotic leak
- Stoma problems (ischaemia, retraction, prolapse, hernia, high output)
In low anterior resections;
- Damage to pelvic nerves (bowel, urinary, sexual dysfunction)
- Possibly impaired fertility in younger females
Describe the cardinal signs and symptoms of bowel obstruction.
- Abdominal pain
- Vomiting
- Absolute constipation (flatus and solids)
- Abdominal distension
