24- Colyrectal Explains Flashcards
What imaging modalities are used for complete staging of colorectal cancer?
CT of the chest, abdomen, and pelvis; colonoscopy or CT colonography; MRI for evaluating the mesorectum in tumors below the peritoneal reflection
What is the main treatment for colon cancer?
Resectional surgery
What are some palliative adjuncts used in the treatment of colon cancer?
Stents, surgical bypass, and diversion stomas
How are colon resections tailored to the patient and tumor location?
Based on the lymphatic drainage, resecting specific lymphatic chains
What factors may influence the choice of procedure for colon cancer treatment?
Confounding factors like HNPCC family history, which may indicate a panproctocolectomy instead of segmental resection
What are the key technical factors for successful healing of an anastomosis after colon resection?
Adequate blood supply, mucosal apposition, and no tissue tension
When is it safer to construct an end stoma instead of attempting an anastomosis after colon resection?
In the presence of surrounding sepsis, unstable patients, or inexperienced surgeons
What are the options for a colonic cancer presenting with an obstructing lesion?
Stenting or resection
What is the common approach for defunctioning a colonic tumor with a proximal loop stoma?
Unusual in modern practice
What treatment is usually offered to patients with risk factors for disease recurrence after colon cancer resection?
Chemotherapy, commonly a combination of 5FU and oxaliplatin
How is rectal cancer management different from colonic cancer?
Due to the rectum’s anatomical location and challenges, rectal tumors can be surgically resected with either an anterior resection or an abdomino-perineal resection (APER)
What determines the choice between anterior resection and APER in rectal cancer surgery?
Involvement of the sphincter complex or very low tumors
What is the required distal clearance margin in rectal cancer surgery?
2 cm
Why is neoadjuvant radiotherapy offered more frequently in rectal cancer compared to colonic cancer?
Because the rectum can be irradiated, unlike colonic tumors
What is the crucial aspect of rectal cancer surgery in addition to rectal tube excision?
Meticulous dissection of the mesorectal fat and lymph nodes (total mesorectal excision/TME)
Which patients with rectal cancer do not require irradiation and can proceed straight to surgery?
Patients with T1, T2, and T3/N0 disease on imaging
What type of radiotherapy is typically offered to patients with T4 rectal cancer?
Long course chemo radiotherapy
What is the recommended treatment approach for obstructing rectal cancer?
Defunctioning loop colostomy, followed by staging and planning for resectional surgery
Summary of cancer resections:
Site of cancer Type of resection Anastomosis Risk of leak
Right colon Right hemicolectomy Ileo-colic Low (<5%)
Transverse colon Extended right hemicolectomy Ileo-colic Low (<5%)
Splenic flexure Extended right hemicolectomy Ileo-colic Low (<5%)
Left colon Left hemicolectomy Colo-colon 2-5%
Sigmoid colon High anterior resection Colo-rectal 5%
Upper rectum Anterior resection (TME) Colo-rectal 5%
Low rectum Anterior resection (Low TME) Colo-rectal (+/- Defunctioning stoma) 10%
Anal verge Abdomino-perineal excision of colon and rectum None n/a
What is the follow-up plan for LNPCP with R1 or non-en bloc resection?
Site check at 2-6 months, then further scope at 12 months
Colonic polyps:What is the risk of malignancy associated with adenomas?
Around 10% in a 1cm adenoma
Colonic polyps:What symptoms can distally sited villous lesions cause?
They may produce mucous and, if very large, electrolyte disturbances may occur
What is the recommended colonoscopy schedule after resection of colorectal cancer?
One year post-resection
What is the follow-up recommendation for large non-pedunculated colorectal polyps (LNPCP) with R0 resection?
One-time scope at 3 years