Colon Flashcards
Failure of Abx therapy for acute diverticulitis after this period of time
72 hours
Colovesicular fistula operative management
Small fistulae are just pinched off, larger required 2 layered closure. Leave foley for 7 days. Cystogram prior to Foley removal.
Immunosuppressed considerations for acute diverticulitis
May need colectomy during initial hospitalization due to higher risk of complications without resection.
Necessary before ileostomy closure
Gastrograffin or hypaque enema.
Key operative step when operating on either cecal or sigmoid volvulus
Divide the mesentery before detorsing to prevent cytokines and bacteria from going systemically.
Older adults, most common cause of LGIB
- Diverticulosis 2. Angiodysplasia 3. Neoplasm 4. Inflammatory bowel disease. 5. Ischemic colitis Also consider hemorrhoids and fissure
Children and younger adults, most common cause of LGIB
- Inflammatory bowel disease. 2. Meckel’s 3. Polyps Also consider hemorrhoids and fissure
Rate of spontaneous cessation of LGIB
80%
REasons NOT to do an ileorectal anastomosis, but rather an end ileostomy.
- HD unstable 2. IBD of terminal ileum or rectum 3. Poor continence pre op 4. Malnutrition
Percent of patients with CRC presenting with synchronous liver lesions
(within 6 months of primary diagnosis) 15%
Percent of patient with CRC presenting with metachronous liver lesions
(greater than 6 months after primary diagnosis) 20%
timing of liver resection for CRC mets after admin of FOLFOX and avastin
6 weeks off avastin and 4 weeks from chemo
5 year survival after resection of single hepatic liver met for CRC
50%
Large bowel obstruction complaining of RLQ abdominal pain
impending rupture of cecum since this is most at risk for mural vessel collapse and ischemia due to largest diameter.
Work up for colon cancer
- CT chest, abdomen and pelvis with IV/PO contrast
- CEA
- Full colonoscopy
Ways to possibly evaluate rest of colon before resection in large bowel obstruction
- Barium enema
- CT enterography
- On table colonoscopy
- Palpation of colon intraop
- 6 month post op colonoscopy
Vessels needed to divide and resect for adequate LN harvest for splenic flexure colon CA resection
- Left branch of middle colic
- left colic
- IMV
(need 12 LNs)
Indications for adjuvant therapy in stage 2 colon cancer
- LVI
- Perineural invasion
- Lack of microsatellite instablity
Surveillance post resection for colon cancer
- CT chest/A/P - annual for 3 years
- Colonoscopy - at 3 years
- CEA - every 3 months for 3 years
- H&P - every 6 months for 5 years
Anastomotic leak rate after sigmoid colon resection
5%
End loop stoma for anastomotic leak after right colectomy (patient with severe sepsis)
If patient stable, can resect and re-do anastomosis
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Algorithms for the following:
- right sided leak - stable patient
- right sided leak - unstable patient
- left sided leak - stable patient - small leak
- left sided leak - unstable patient - large leak
- resect anastomosis and redo
- resect anastomosis and to end-loop (end ileostomy and take the antimesenteric corner from the colon and mature it.
- primary repair, omental butress, loop ileostomy, endoscopy +/- clipping
- Staple distal end, bring up end colostomy
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Infectious causes of large bowel obstruction
- yersinia
- Ascaris
- Taneia
- TB
Extent of extended right colectomy in patient with transverse colon mass
Ascending branch of left colic
INdications for colectomy in recurrent uncomplicated diverticulitis
- Recurrent attackes crescendoing
- Stricture
- Demanding job that makes uncomplicated attack unsafe or inconvenient.
(rate of complication for resection of uncomplicated disease < 5%)
differential for abdominal pain and bloody BM
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If surgery and resection for ischemic colitis after aortic surgery, should primary anastomosis be attemptoed
No, risk of graft contamination if leaks.
Ulcerative coliits - severe colitis (Truelove and Witts)
- > 6 bloody BMs per day and one of following
- Temp > 37.5
- Pulse > 90
- Hb < 10.5
- ESR > 30
Complications of IPAA
- Frequent BMs and leaking
- Pouchitis
- Pouch failure
- Infertility
Differential for RLQ pain
- Appendicitis
- Crohn’s
- Infecitous coliits
- Typhlitis
- Tubo-ovarian abscess
- Ovarian torsion
- Ectopic
- UTI
- Nephrolithiasis
- Meckel’s diverticulitis
3 categories of disease behavior for Crohn’s
- Inflammatory
- Stricuring
- Fistulizing
work up if concerned for Crohn’s
- MR enterography
- EGD w biopsy
- Colonoscopy (after inflammation resolved) - sigmoidoscopy for biopsy if need tissue
Induction and maintenance for mild to moderate Crohns and maintenance for moderate to severe
Induction
- Budesonide - mild
- Prednisone - moderate
Maintenance
- 5-ASA or mesalamine
- Moderate to severe-Anti TNF antibodies or 6-MP or azathioprine
Indications for surgery in Crohns
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Risk of additional surgery necessary in Crohn’s diasease at 10 years?
50%
Breakdown of intestinal NETs
- Small bowel 50%
- Rectum 20%
- Appendix 20%
Breakdown of appendiceal tumors
- ?
- NET 30%
- Adenocarcinoma 30% (50% of which are mucinous)
Indications for further work up if appendiceal NET found
- size > 2 cm
- high grade (ki 67 > 20 or mitoses > 20)
(modalities include chromogranin A, Dotatate scan, colonoscopy and possibly EGD)
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Difference between appendiceal NET and appendiceal adenocarcinoma
Appendectomy alone sometime appropriate for NET, but adenocarcinoma of appendix always requires right hemicolectomy
Unknown mass < 2 cm involving base of appendix
Perform cecectomy and appendectomy with en bloc resection of mesoappendix.
Chemoradiation regimen for locally advanced rectal cancer
5000 cGy over 25 fractions (5 weeks M-F) w oral capcitibine or infusional 5-FU
When is surgery scheduled for proctectomy after neoadjuvant chemoradiation
8-12 weeks (but only after repeat endoscopy and MRI)
Pre op discussion points for proctectomy
- Possible need for stoma
- LAR syndrome (frequent stooling)
- Sexual and bladder dysfunction
Fascia anterior to rectum in males
Denonvilliers fascia
Fascia posterior to rectum
Waldeyer’s fascia (describe dividing the avascular plane between the parietal and visceral endopelvic fascia)
Desired margin for high rectal cancers
5 cm
Margin needed for mid to low rectal cancers
ideally 2 cm, but even 1 cm if patient received neoadjuvant chemoradiation in okay.
Anastomotic leak rate for low pelvic anastomosis
15%
Surveillance for rectal cancer
- CEA every 3 months for 2 years, and 6 months for 3 years after with H&P and rectal exam
- CT C/A/P annually for 3 years
- Colonoscopy at 1 year and at 3 years
STaging for anal cancer
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NIgro protocol for anal cancer (radiation and chemotherapy)
45 Gy administered over 25 fractions (5 weeks)
5FU (or capcitibine) on days 1-4, 29-32 and mitomycin c on days 1 and 29.
Systemic treatment for metastatic
5-FU and cisplatin
Treatment for T1 anal margin cancers
Wide local excision with 1 cm margin (re-excision if positive margin) or Nigro protocol if anatomically not possible.
Response of anal cancer to Nigro protocol can continue for up to..
26 weeks
Treatment for anal cancer still present after Nigro protocol and appropriate observation
APR (+/- ingiunal node dissection if tumor present in nodes)
Post chemo survellance for anal cancer
Essentially same as CRC
H&P and exam every 3 months for 2 years and 6 months for additional 3 years; with anoscopy and acetic acid testing
CT C/A/P for 3 years
Areas of peri-anal/rectal abscesses
- Perianal
- Intersphincteric
- Ischiorectal
- Supralevator
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Work up for GI neuroendocrine tumors
- CT C/A/P with IV contrast
- Biochemical markers as appropriate
- Gallium dotatate PET scan
- Colonoscopy for colon NET, EGD/EUS for gastric or duodenal NET, Endorectal U/S for rectal NET, capsule endoscopy for small bowel NET.
Treatement for rectal NET
- Make sure to fully evaluate colon with colonoscopy and then CT scans and gallium dotatate scan
- Lesions < 1 cm - endoscopic resection with close surveillance
- Lesions < 2 cm and T1 lesions - transanal excision
- Lesions > 2 cm, T2, dor LN involvement - LAR or APR
Duration of therapy for adjuvant chemotharapy for high risk stage II or stage III colon cancer
Multidisciplinary conference
3-6 months of Cape-OX or FOLFOX
Numbers of new colon cancer diagnosed per year (rectal cancer? )
100k new colon cancer diagnoses per year
44 k new rectal cancer diagnoses per year.
Indications for adjuvant chemotherapy for colon cancer
- All stage III (FOLFOX or CAPEOX)
- Stage II with high risk features (FOLFOX or CAPEOX)
- Stage II with Microsatellite stable (MSS) or proficient MMR can be observed or capecitibine or 5FU/leucovorin
(stage II with MSI-H and stage I should not get adjuvant therapy)
Lesion requirements for transanal excision of rectal cancer
- T1
- < 3 cm
- < 30% of circumference
- < 8 cm from anal verge
- No PNI or LVI
Rate of local recurrence for rectal cancer
German, Dutch, and swedish rectal cancer studies
With neoadjuvant therapy (radiation or chemoradiation) ranges from 2-11% local recurrence.
Work up for diagnosed anal or perianal cancer
- History and physical exam to include DRE, anoscopy, inguinal exam
- CT C/A/P
- PET scan
- HIV testing
- Gynecologic exam with cerivcal screening if female.
What defines stage III anal cancer
Any N or T4 (invading bladder, vagina, urethra)
HPV subtypes with anal cancer
16, 18
Treatement for AIN
Imiquimod or topical 5-FU (HPV immunization also likely preventative)
Superficially invasive anal cancer treatment
Local excision (with biopsy) if < 3 mm invasion of basement membrane and < 7 mm horitzontal spread
Excision of perianal cancer is acceptable if
(T1 (< 2 cm) or limited T2 lesion) that are well differentiated that do not involve sphincter
Surveillance after treated anal or perianal cancer
- DRE, H&P every 6 months for 5 years
- Anoscopy every 6 months for 3 years
- CT C/A/P annually for 3 years
Treatment for groin recurrence but good response to anal lesion
Groin dissection or chemoradiation to groin.
Treatment for progressive or recurrent anal diasese
APR
Indications for repeat colonoscopy in 5 years
Low risk adenoma or low risk sessile serrated polyp (< 1cm), less than or equal to 2 adenomatous polyps
Indications for repeat colonoscopy in 3 years
Villou or tubulovillous adenoma
adenoma > 1 cm
betweeen 3-10 adenomatous or sessile polyps
High grade dysplasia
Surveillance after removal of large polyp (lateral spreading lesion > 2 cm)
Repeat colonoscopy in 1 year (6 months of removed piecemeal)
Colonoscopy indications in UC or Crohn’s colitis
8 years after diagnosis
Chromendoscopy with targeted biopsy
HD White light endoscopy with 4 quadrant biopsies every 10 cm
Colonoscopy indications for greater than or equal to 1 first degree relative with CRC (or with advanced adenoma)
Colonoscopy at 40 or 10 years before diagnosis of relative, followed by repeat colonoscopy every 5 years
Lynch syndrome screening highlights
Colonoscopy starting at 20 or 5 years before familial diagnosis, then repeat every 1-2 years
May be benefit for prophylactic BSO at some point
Screening MRCP starting at 50 for pancreatic cancer.
FAP (with known APC positive) screening
annual colonoscopies starting age 15
EGDs starting age 20
thyroid U/S
When is colectomy recommended for FAP, attenuated FAP, or mFAP
when polp burden such that can’t be evaluated or dysplasia present.
Muir Torre syndrome is associated with colorectal cancer and this carcinoma (dominant or recessive)
Sebaceous gland tumors (dominant)
Toxic megacoloin in Ulcerative Colitis is a diameter of the transverse colon greater than
6 cm
Requirements for endoscopic surveillance after endoscopic surveillance after endoscopic excision of invasive colon cancer
- single specimen with invasive disease
- Polyp is successfully removed with favorable histology (Grade I or II and no evidence of LVI)
- Margins are clear (margin 2 mm or greater)
Blood supply to colon after extended right colectomy
Marginal artery of Drummond.
Most important prognostic indicator in GIST
mitotic index (> 5-50)
other incluse size > 5 cm, location outside of stomach, necrosis
Most common cause of anorectal bleeding
hemorrhoids followed by fissure then ulcers
5 year survival after complete resection of colorectal liver met
40%
Indications for transanal resection of rectal cancer
- Within 8 cm of anal verge
- < 30% circumference
- T1 lesion
- Mobile, non fixed
- < 3 cm in size
Indications for resection of colonic lipoma
- Size > 2 cm
- Bleeding
- Obstruction
Indications for adjuvant chemotherapy in Stage II colon cancer
- Inadequate nodal harvest
- LVI
- PNI
4.
Total mesorectal excision stats
Improved survival (what to what)
Decreased local recurrence (what to what)
- 50% to 75%
- 30% to 5%
Gardeners syndrome
abdominal wall and mesenteric desmoid
osteomas of mandible or skull
epidermoid cysts
Turcot’s syndrome
Central nervous system tumors
GI polyposis
Colorectal cancer
HPV types in benign condyloma acuminata (2) and anal SCC (2)
Benign 6 and 11
SCC 16, 18
Excision margin if high grade intraepithelial SCC is resected
high grade 6 mm
(after failure of topical therapy - imiquimod, topical 5FU,
GIST percentages (small bowel, stomach, rectal, colonic)
25%, 30%, 15%, 10%
Incidence of metastasis to LN of colon NET based on size (< 1cm, 2cm or greater)
< 5%, 79%
Modified Hanley procedure
Treatment of horshoe abscess (posterior midline incision for post anal space with bilateral ischiorectal fossa incisions)
Treatment for well or moderately differentiated, T`1N0, SCC of the anal canal
Excision with 1 cm margins (compared to poorly differentiated T1N0 or higher, which gets Nigro protocol)
Treatment for anal melanoma (non metastatic)
local exision vs APR
Treatment for anal adenocarcinoma
APR with adjuvant chemotherapy
Mismatch repair proficient responds to chemotherapy (T/F)
pMMR DOES respond to chemotherapy , dMMR does NOT
(deficient (negative) no chemotherapy (but better prognosis))
Indications for right hemicolectomy for appendiceal NET (carcinoid)
- Any size at base
- > 2 cm at tip/body
- Any size with LVI
- Any size with > 3 mm invasion into mesoappendix
- Mixed histology (goblet cell carcinoid, adenocarcinoid)
- High grade (G2/G3 or high mitotic/Ki67 index)
Percentage of recurrent appendicitis after treatment of appendicitis with Abx
5-35%
follow up after piecemeal resection of adenomatous polyp
6 months
Maximum diameter of vessel that can be sealed with energy device
7mm
Upper Endoscopy intervals for following
FAP
Varices after banding
Gastric ulcer
Esophageal ulcer
Barretts
Barrets with LGD
EGD every 1-2 years
6-8 weeks
Q6 weeks until healed
Q6 weeks until healed
Q 1-2 years
6 months
Malignant potential of small bowel villous adenoma
30-40%
Brunner’s gland adenoma (small bowel) has malignant potential (T/F)
False
Most common small bowel tumor
adenoma
Three most common small bowel malignancies
Adenocarcinoma (50%)
Carcinoid (NET)(40%)
GIST (10%)
Second most common cause of death in FAP
desmoid tumors
(second most common malignant cause - periampullary tumors)
What size duodenal polyps are amenable to endoscopic resection
1cm