Surgery CRC

Question 1

benign vs malignant tumors of the git

Answer 1

benign: adenomas (premalignant, most common, colon), hamartomas, lipomas
malignant: adenocarcinomas (most common, colon), lymphoma, gist, squaca (esophagus and anus)

Question 2

epidemiology of git tumors

Answer 2

• males: second most common
• females: third most common
• both sexes: third most common

(same for world and Philippines)

Question 3

warning signs for crc

Answer 3

• 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

Question 4

progression from adenoma to carcinoma takes ___

Answer 4

10 years

removing polyps = minimizes risk of progression

Question 5

t/f according to the cochrane meta-analysis in 2005, fobt is an effective way to screen for crc

Answer 5

true!! reduced crc mortality by 16%

Question 6

indications for crc screening

Answer 6

• general population over 50 (but now dropped to 45)
• rectal exam, fobt yearly
• flexible sigmoidoscopy every 3-5 yrs
• colonoscopy every 10 years

Question 7

gold standard for diagnosis

Answer 7

colonoscopy

Question 8

indications for colonoscopy at 25 yo

Answer 8

• high risk individuals with strong fhx

- or 10 years earlier than the youngest relative at age of diagnosis

Question 9

staging and survival rates of crc

Answer 9

I = only portion of the bowel wall = 90%
II = beyond whole bowel wall = 80%
III = lymph nodes = 50%
IV = distant organs = 5%

Question 10

treatment for colon cancer by stage

Answer 10

I = surgery
II = surgery +/- chemo
III = surgery + chemo
IV +/- surgery +/- chemo

Question 11

treatment for rectal cancer by stage

Answer 11

I surgery
II surgery + radiochemo
III surgery + radiochemo
IV +/- surgery +/- chemo

Question 12

rationale for radiochemo for rectal cancer

Answer 12

has higher risk for local recurrence

Question 13

treatment goals for crc

Answer 13

• local and regional control (surgery and rad)
• systemic control
  (chemo)

Question 14

principles of crc surgery

Answer 14

• 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

Question 15

targets for tumor in the right colon

Answer 15

root of ileocolic artery, right colic artery, right branch of middle colic artery

Question 16

targets for tumor on the hepatic flexure

Answer 16

root of ileocolic artery, right colic artery, right branch of middle colic artery, middle colic artery

Question 17

targets for tumor on the left colon

Answer 17

left colic artery and left branch of middle colic artery

Question 18

targets if tumor is on sigmoid

Answer 18

sigmoidal artery or arteries involving left colon (superior / inferior mesenteric artery)

Question 19

targets if tumor is close to or within rectum

Answer 19

root of superior rectal artery, inferior mesentertiic artery

Question 20

two types of sphincter preserving surgeries

Answer 20

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)

Question 21

what is sphincter sacrifice

Answer 21

when anal sphincter is removed using abdominoperineal excision

Question 22

gold standard for rectal ca treatment

Answer 22

total mesorectal excision

Question 23

surgical objectives in total mesorectal excision

Answer 23

• specimen oriented dissection
• nerve preservation
• sphincter preservation for 80%
• acceptable functional outcomes
• minimum post-op morbidity

Question 24

indications for stoma

Answer 24

• 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)

Question 25

comparison of procedures loop ileostomies and transverse loop colostomies

Answer 25

ileum: more liquid, less odorous, more volume, high risk for excoriations

transverse loop colostomies: more solid output, malodorous, less volume, loud gas