Colorectal Surgery Flashcards
When can you do a transrectal excision of a rectal carcinoid tumor
meets following criteria:
- smaller than 1 CM
- freely mobile
- < 12 cm from dentate line
- no lymphadenopathy
is it better to do a staged or simultaneous repair of a vaginal and rectal prolapse?
simultaneous repair has better outcomes with less recurrence of prolapse
initial management for fecal incontinence
lifestyle modification, always first
what is the first step in a patient with a reducible rectal prolapse?
colonoscopy
how many lymph nodes are recommended for mesenteric lymphadenectomy
at least 12 node harvest for adequate staging
what is the role of somatostatin in neuroendocrine tumors
control symptoms once it is metastatic
how would you excise a rectal carcinoid tumor > 1 cm in size
proctectomty with mesorectal excision
another name for rectal prolapse
rectal procidentia
you read signet-ring component from colorectal cancer…what should you think about
Microsatellite instability
patient who has failed conservative management for fecal incontinence, next step
imaging
- endoanal ultrasound
or - MRI
where does anal margin start
lateral to the intersphinteric groove and extends 5cm out from that point
how do you treat SCC of the anal margin
- < 1cm excise it
- > T1 lesion or with LN involvement = chemoradiation like SCC of anal canal
what is the cut off to excise a thrombosed hemorrhoid?
- < 72 hour history = excision
what is an anal marginal cancer
cancer located within the anal margin (from intersphincteric groove out 5 cm)
when can you do local excision on an anal margin SCC
- less than 2 cm in size
- well differentiated
- no LN involvement
how do you drain a horseshoe abscess
internal posterior sphincterotomy with counter incisions bilaterally in the ischioanal fossae
most common extra-colonic malignancy in Lynch syndrome
endometrial cancer
when would you not do a proctocolectomy for UC if you saw atypia on a biopsy?
if there is active inflammation, the atypia may resolve after treatment
what kinds of hemorrhoids can be banded?
only internal hemorrhoids
surveillance for stage 1 colon cancer
colonoscopy at 1 year
from NCCN guidelines
surveillance for stage II or III colon cancer
- H+P+CEA every 3-6 months for 2 years, then every 6 months for 5 years
- CT CAP every 6-12 months for 5 years
- Colonoscopy at 1 year
per NCCN
surveillance for stage IV colon cancer
- H+P+CEA every 3-6 months for 2 years, then every 6 months for 5 years
- CT CAP every 3-6 months for 2 years, then every 6-12 months for 5 years
- Colonoscopy at 1 year
per NCCN
which colon resection does not require low lithotomy position?
right hemicolectomy
patient presents with new-onset bloody diarrhea and weight loss. Colonoscopy reveals acute colitis with biopsies showing mucosal inflammation and giant cell granulomas…what do they have
- Acute Crohn’s flare
Patient with cecal volvulus, next step
Segmental Colonic resection
Treatment for mild to moderate ischemic colitis
- intravenous fluids
- broad spectrum antibiotics
- bowel rest
which biliary disease is tied to ulcerative colitis
primary sclerosing cholangitis
Which extra colonic manifestations of UC improve after colectomy?
- ocular problems
- arthritis
- pyoderma gangrenosum (50% of the time)
What extra manifestations of UC do not improve after total abdominal colectomy?
- primary sclerosing cholangitis
- ankylosing spondylitis
how long do you wait after chemoradiation for anal squamous cell carcinoma to determine if the patient has residual disease
6 months
what is the space of Retzius
the extra-peritoneal space between the pubic symphysis and the bladder
what is the procedure of choice for a patient with an anal sphincter defect?
- overlying sphincterplasty
Colonoscopy/histology findings that would necessitate repeat in 3 years
- serrated adenoma
- high grade dysplasia
- villous or tubulovillous histology
- 3-10 adenomatous polyps
- polyp >/= 1 cm
what is the treatment for a low rectovaginal fistula?
rectal advancement flap
what kind of bowel prep is recommended for elective colorectal cases?
mechanical and oral antibiotics
tenets of rubber band ligation in treating hemorrhoids?
- band 2cm above dentate line
- band only redundant mucosa
for patients with Anal squamous cell carcinoma s/p Nirgo protocol who has persistent disease, what is the next step
Biopsy to confirm cancer before any resection is undertaken
after a sigmoidectomy with high ligation, what is the remaining distal bowel perfused by
Marginal artery from SMA
best first line treatment for idiopathic pouchitis
Oral ciprofloxacin
what should you do for a patient with a lateral anal fissure
EUA with biopsy if appropriate
Complication of stapled hemorrhoidopexy in women, unique to it being stapled
rectovaginal fistula
Alternative treatment for internal hemorrhoids, for a patient on anti-coagulation
Sclerotherapy
If you suspect an intestinal neuroendocrine tumor
(NET), what test(s) should you order to gain further information?
- Serum chromogranin A
- 24 hour urine 5-HIAA
what is 5-HT, hint: it relates to NETs
5-hydroxytryptamine (AKA: serotonin)
what is 5-HIAA, hint: it relates to NETs
5-hydroxyindoleacetic acid (AKA: main metabolite of serotonin, excreted in urine)
risk of incontinence after lateral internal sphincterotomy
8-30%
difference between trans-anal and trans-abdominal resection of a rectal adenocarcinoma, when comparing recurrence rates
trans-anal resection comes with a higher rate of local recurrence
which vessel do you ligate in a mid-descending colon cancer?
inferior mesenteric artery
what conservative therapy can you offer for internal hemorrhoids in a patient on blood thinners, who has already tried life style modification
sclerotherapy
- less risk of bleeding than band ligation
most common complication after loop ileostomy reversal
bowel obstruction (7% risk)
You are unable to get the left colon to reach the upper rectum without tension, despite takedown of the splenic flexure and full dissection of the left mesocolon off the retroperitoneum. What is the next step to obtain more length?
divide the inferior mesenteric vein, should free colon from the central mesentery and give you enough length
Patient s/p perianal wart removal, pathology returns with high and low grade dysplasia. How often should they be re-evaluated for lesions
every 6 months anoscopy and digital rectal examination
this is for both high grade OR low grade dysplasia
Amsterdam criteria for Hereditary non-polyposis Colorectal cancer
- at least 3 family members with proven adenocarcinoma (one is a first degree relative)
- at least 2 generations involved
- at least one person diagnosed before the age of 50
What is the genetic mutation in HNPCC
DNA mismatch repair mutation
(MLH1, MSH2, MSH6, PMS2, or EPCAM)
Length of a Ileal J pouch?
15-20 cm
When do you start screening for colorectal cancer in patients with inflammatory bowel disease?
8 years after diagnosis, or at the age of 40 whichever is first
anterior border for a total mesorectal excision during a low anterior resection
Denonvilliers fascia
what diameter of colon (except cecum) with toxic megacolon?
> 5.5 cm
when do you start screening for colorectal cancer in patient with IBD?
8 years after diagnosis
what is FOLFOX chemotherapy?
FOLinic acid
Flourouracil
OXaliplatin
what chemotherapy regimen is currently used in colorectal cancer?
FOLFOX
folinic acid, flourouracil, oxaliplatin
role of CEA in colorectal cancer
most sensitive at detecting hepatic or retroperitoneal mets from colorectal cancer
primary source of energy for enterocytes
Glutamine
primary source of energy for colonocytes
short chain fatty acids
Acetate, butyrate, propionate
What bacteria is associated with Colorectal Cancer?
Clostridium Septicum
Superior rectal artery supply
IMA
Middle rectal artery supply
internal iliac arteries
inferior rectal artery supply
pudendal artery
