Surgery CRC Flashcards
benign vs malignant tumors of the git
benign: adenomas (premalignant, most common, colon), hamartomas, lipomas
malignant: adenocarcinomas (most common, colon), lymphoma, gist, squaca (esophagus and anus)
epidemiology of git tumors
- males: second most common
- females: third most common
- both sexes: third most common
(same for world and Philippines)
warning signs for crc
- blood in stools
- change in bowel habits (diarrhea or constipation)
- abdominal discomfort, cramping, or pain (esp when obstructed)
- unexplained weight loss
- anemia or pallor when occult bleeding
progression from adenoma to carcinoma takes ___
10 years
removing polyps = minimizes risk of progression
t/f according to the cochrane meta-analysis in 2005, fobt is an effective way to screen for crc
true!! reduced crc mortality by 16%
indications for crc screening
- general population over 50 (but now dropped to 45)
- rectal exam, fobt yearly
- flexible sigmoidoscopy every 3-5 yrs
- colonoscopy every 10 years
gold standard for diagnosis
colonoscopy
indications for colonoscopy at 25 yo
- high risk individuals with strong fhx
- or 10 years earlier than the youngest relative at age of diagnosis
staging and survival rates of crc
I = only portion of the bowel wall = 90% II = beyond whole bowel wall = 80% III = lymph nodes = 50% IV = distant organs = 5%
treatment for colon cancer by stage
I = surgery
II = surgery +/- chemo
III = surgery + chemo
IV +/- surgery +/- chemo
treatment for rectal cancer by stage
I surgery
II surgery + radiochemo
III surgery + radiochemo
IV +/- surgery +/- chemo
rationale for radiochemo for rectal cancer
has higher risk for local recurrence
treatment goals for crc
- local and regional control (surgery and rad)
- systemic control
(chemo)
principles of crc surgery
- goal: preservation of function
- wide clearance: at least 5 cm margin for colon ca, at least 2 cm margin for rectal ca
- lymph node clearance
targets for tumor in the right colon
root of ileocolic artery, right colic artery, right branch of middle colic artery
targets for tumor on the hepatic flexure
root of ileocolic artery, right colic artery, right branch of middle colic artery, middle colic artery
targets for tumor on the left colon
left colic artery and left branch of middle colic artery
targets if tumor is on sigmoid
sigmoidal artery or arteries involving left colon (superior / inferior mesenteric artery)
targets if tumor is close to or within rectum
root of superior rectal artery, inferior mesentertiic artery
two types of sphincter preserving surgeries
anterior resection and wide mesorectal excision (for above rectal muscles)
low anterior resection and total mesorectal excision (for tumors closer to peritoneal reflection, for lower and middle rectal tumors)
what is sphincter sacrifice
when anal sphincter is removed using abdominoperineal excision
gold standard for rectal ca treatment
total mesorectal excision
surgical objectives in total mesorectal excision
- specimen oriented dissection
- nerve preservation
- sphincter preservation for 80%
- acceptable functional outcomes
- minimum post-op morbidity
indications for stoma
- to prevent further fecal leakage from a repair or wound in colon (colonic trauma, colonic perforations)
- expected poor wound healing (peritonitis, malnutrition, questionable viability, comorbids)
- protect a more distal anastomosis or repair
- middle and low rectal ca (prone to leakage)
comparison of procedures loop ileostomies and transverse loop colostomies
ileum: more liquid, less odorous, more volume, high risk for excoriations
transverse loop colostomies: more solid output, malodorous, less volume, loud gas
