Colorectal Flashcards
Compared to the traditional hemorrhoidectomies, using an electrothermal tissue-sealing device is associated with a lower rate of?
Immediate post-op pain- equivalates with traditional at 2 weeks post-op.
Faster return to work
Poor prognostic indicators of anal cancer? (5)
Size >5cm
>2/3 involvement of the anal canal circumference
Other:
Male sex
Presence of nodal disease
Hgb<13
Colonic stens for obstructing cancer vs operation without stens
- what is the incidence of colonic obstruction with malignancy?
- difference in 30d mortality?
- % chance of successful laparoscopic resection?
- surgical site infxn rate?
- most common site of stent migration?
- 30%
- no difference in mortality
- significant improved lap rxn rate (67% with stent vs. 31.4% without)
- SSI lower with stent
- MC site of stent migration is rectosigmoid jxn
When to do follow-up colonoscopies 3 yrs after polypectomy (4)
Low risk vs high risk polyps?
When to rpt at 6mo?
When to do rpt scope after completely resecting cancerous polyp with margin > 2mm?
3 years: - >10 adenomas - tubular adenoma > 10mm - high grade dysplasia - villous adenoma (10, 10, high villain)
Low risk: 1-2 tubular adenomas, <10mm -> 5-10 years
High risk: 3 or more adenomas, or size >10mm -> 3 years
Large polyp removed in piecemeal fashion -> 6 mo
1yr
Multitarget stool DNA test vs. decal occult testing
Sensitivity for cancer vs. adenoma
Specificity?
Multitarget stool DNA: 92% sensitivity for detecting colorectal cancer but 42% for adenoma
Fecal occult: 74% for cancer and 24% for adenomas
Fecal occult specificity is better 96% vs 89
Criteria for transanal excision (4)
1) <3cm
2) <30% circumference
3) within 8cm from anal verge
4) T1
How do you do a ripstein repair? 3 steps
What is it’s most common morbidity? Whats the frequency?
What is the most severe complication?
1) mobilize the rectum
2) put a mesh around the rectum
3) fix the mesh to the presacral fascia
- constipation >50% with pre-op constipation
>10% without pre-op constipation
Most severe: mesh erosion but less common
Long term complications of J-pouch:
- what are the frequencies for sexual dysfunction, stricture, pouchitis
Pouchitis: 30-50%
Stricture: 7-15%
Sexual dysfunction: 1-20%
Treatment for obstetric tear, fecal incontinence?
What about for complex / recurrent cases?
Wrap around sphincteroplasty - mobilize the sphincters and reapproximate without tension
Gracillis muscle transposition with constant low freq stimulation
What innervates the external sphincter?
It is continuous with what muscles?
What innervates the internal sphincters?
Inferior rectal branch of the internal pudendal nerve
+
Perineal branch of the 4th sacral nerve
Continuous with puborectalis and levator ani
Internal sphincters are innervates by autonomic system. Continuous with circular muscle of the rectum.
What is lymphogranuloma venerum?
Treatment?
Treatment should begin immediately to prevent what kind of complications?
Chlamydia infxn
Tetracycline
Rectal stricture, perianal fistulas
When you’re removing a condyloma what skin layer should be removed with it?
Epidermis
What is the cause for urinary retention after hemorrhoidectomy?
Pelvic floor muscle spasm in combination with epidural or spinal anesthesia, pain, excessive fluid
What is a Whitehead hemorrhoidectomy?
Circumferential excision of the internal hemorrhoids just proximal to the dentate line
Most common site of recurrence after colon CA resection?
What is the rate of locoregional recurrence after colon CA rxn?
Liver
Locoregional recurrence: <5%
Colorectal cancer
- what is the difference between T4a vs. T4b?
- difference between N1 vs. N2a vs. N2b
- what is stage IIC? IIIC?
- T4a: invades through the visceral peritoneum. Includes gross perforation
T4b: other organ - N1: 1-3 nodes
N2a: 4-6 regional nodes
N2b: seven or more nodes - IIC: T4b/N0/M0. Other organ, no nodes
IIIIC:
T4a/N2a/M0
T3-T4a/N2b/M0
T4b/N1-2/M0
What is the most common complication of strictureplasty? and incidence?
Bleeding. Up to 9% of cases
Leak, dehiscence, sbo all occur at about 2%
Recommended age of colonoscopy if father had colon cancer at age 62?
Current NCCN guideline in a pt with one or more first degree relatives who had colon cancer at ANY age is colonoscopy at age 40 or 10 years before the age at which the relative was diagnosed. Whichevers earlier.
Repeat scope every 5 years
dMMR good or bad? Does chemo work or not?
Mismatch repair deficiency considered favorable prognostic factor. Poor response to fluoropyrimidine based chemotherapy
chemo works well for pMMR but poorer prognostication compared to dMMR
Is APC a tumor suppressor or proto-onco? Is it the first step or the last step in the sequence of colon CA development?
HNPCC is associated with what defect?
Is p53 a tumor suppressor or proto onco?
APC is a tumor suppressor. First step. Then K-ras, DCC, p53
HNPCC: microsatellite instability
P53 is tumor suppressor
What supplies the transverse colon after an extended right?
What does Arc of riolan connect?
Marginal a. of drummond
Connects middle colic and left colic. Smaller contribution than marginal a. of drummond
What is the best prognostic indicators for resecting liver met after colon cancer?
Good response to chemo is the best prog. Indicator
Criteria for local excision of rectal cancer
Size <4 cm Mobile, non-fixed <40% circumference <8 cm from anal verge T1/N0 or T2/N0
Incidence of appendiceal cancer in appendectomy specimen?
~1%
For what kind of tumors is appendectomy sufficient?
It has to be non-epithelial.
Size <2 cm
No involvement of the base.
histologic Grade < II
no goblet cells
Size >2 cm or involvement of base -> right hemi
Required timeframe for something to qualify as chronic appendicitis?
3 or more weeks. At least 1 episode of acute pain.
Mutation in mismatch repair (MMR)
Which colonic syndrome?
Lynch syndrome
Microsatellite instability
Which colonic syndrome?
Lynch syndrome
Screening recommendations for FAP
Flex sig starting at 10-15
Upper endoscopy starting at 25-30
When do you offer surgery for pts with FAP?
As soon as you start to see polyps
Young, <50yo pt with right sided colon cancer. Suspect what?
HNPCC
T3N0 colon CA in a pt with HNPCC. Chemo or no?
No. HNPCC have better prognosis stage for stage. T3N0 actually doesn’t benefit from getting chemo
Recommended surgical treatment for pts with HNPCC for young pt vs. older pt?
Younger: subtotal colectomy with IRA
older: segmental colectomy
Other associated cancers for HNPCC?
Uterine, gastric, GU tumors
Screening recommendation for known HNPCC?
Colonoscopy starting at age 20-25
Endometrial aspiration starting at age 25-35
Describe the haggitt classification
For pedunculated polyps
Haggitt 0: not invading muscularis
Haggitt 1: invades through the muscularis but only in the head
Haggitt 2: invades the level of the neck
Haggitt 3: invades any part of the stalk
Haggitt 4: invades into the Submucosa of the bowel wall below the stalk but above the muscularis propria
Proto oncogene or tumor suppressor?
- APC
- K-ras
- p53
- DCC
- APC: Tumor suppressor. Defect in APC -> No tumor suppression
- K-ras: proto oncogene
- p53: tumor suppressor
- DCC: tumor suppressor
Margin and # nodes you need for colon CA?
5cm margin, 12 nodes
Run of the mill T3N0 colon cancer. Chemo or no?
Yes chemo. HNPCC T3N0 don’t need chemo
this is stage IIa
stage IIb: T4a N0
stage IIc: T4b N0
IN THE HINDGUT, where is GIST found most frequently?
Rectum
Over GIST frequency
gastric pacemaker cells Stomach (50-70%) > small bowel (25-35%) > colorectal (5-10%) > mesentery/omentum (7%) > esophagus (<5%) > duodenum
Rate of bleeding required to detect GI bleed on angio?
At least 1mL/min
RBC scan: 0.1-0.5mL/min
Rate of bleeding required to detect bleeding on tagged RVC scan?
0.1-0.5mL/min
Angio: 1mL/min
What is the risk of colonic perforation in pts with recurrent uncomplicated diverticulitis?
<5%
What is a Turnbull blowhole colostomy?
An incision is made over the dilated transverse colon. The colon wall is sutured to the peritoneum to prevent intra-abdominal contamination. The colon is opened and the edges of the opened bowel are sutured to the skin
requires minimal anesthesia and operative time. for toxic megacolon and large bowel obstruction
% risk factor for developing cancer for ulcerative colitis at 10 years, 20 years and 30 years after diagnosis?
10 years: 2%
20 years: 8%
30 years: 18%
0.5% per year between 10-20yr
1% per year thereafter
What sort of ECF output is considered high output?
> 500cc/24hr
What % of patients with Crohn disease develop cancer at 30 years after diagnosis?
What about risk for small bowel adenocarcinoma?
only 6%
Small bowel adeno: 10-12 fold higher risk, majority in the ileum
Overall incidence of cancer in pts with ulcerative colitis?
At 10, 20, 30 years after diagnosis of UC, what % of UC pts will have colorectal CA?
5%
2% at 10 years
8% at 20 years
18% at 30 years
What is the surgical procedure of choice for ppl with anal fissures and hypotonic sphincter?
What causes this?
Usually from previous surgery or obstetric injury
*treatment: Fissurectomy with an anocutaneous advancement flap
What is a coloplasty and when do you do it?
Longitudinal incision along the antimesenteric border and close transversely.
Used when not enough colonic mobility exists for the Jpouch or if the ot has a narrow pelvis
Pt had hartmann years ago. Persistent distal colitis. What to do?
Disuse colitis. Butyric acid enema
anorectal infections in neutropenic patients
What is a preferred mode of imaging?
What is the most common/early sign?
Early surgical intervention necessary?
MRI > CT. Better at seeing fistulas and edema
Pain. Pus is a later sign because of neutropenia
Surgical drainage is reserved for later in the patient’s course when neutropenia resolves and abscesses or fluid collection develop. Surgical incisions at this time are usually smaller and localized. Earlier surgical exploration was often associated with larger incisions, creating wound management problems.
For diverticular abscess s/p IR drainage, the abx should be stopped 4 days after what?
Wbc < 11k
T < 38
Able to eat at least half of regular diet
As part of the eras protocol, why give 100g of glucose orally before the surgery?
what effect does this have on gastric emptying, blood glc, SSI rate?
Reduce insulin resistance.
Traditional fasting leads to depletion of glycogen, insulin resistance and gluconeogenesis.
Does not affect infection rate, gastric emptying. They don’t become hyperglycemic.
For FAP, pts are at the highest risk of developing what types of cancer other than CRC?? Second highest?
1 other than CRS: soft tissue tumors. Desmoid tumors. Most common extraintestinal manifestation: gastric fundus polyps
2 Chemo agents approved for metastatic colon CA and it’s mechanism of action and side effect?
1) Bevacizumab aka avastin (Anti-VEGF)
Impaired wound healing, bowel perf
2) Cetiximab aka erbitux (anti-egfr)
Side effect of irinotecan?
Diarrhea
Myelosuppression
What is the most common long term complication of colostomy?
Parastomal hernia. As many as 50% of all stomas
Surgical options for rectal prolapse:
- history of incontinence
- history of constipation
Incontinence: do levatorplasty to bolster pelvic floor
Constipation: resection rectopexy
Define the different types of FAP based on number of polyps seen on colonoscopy
50-100: attenuated FAP
100-1000: mild FAP
> 1000: severe/profuse FAP
How does smoking affect Crohn’s disease?
Increases the incidence of relapse and failure of maintenance therapy
Anal lesion: “large, eccentric nuclei with pale staining vacuolated cytoplasm”
Perianal pagets disease.
What is the difference between hinchey Ia and Ib?
What is the size limit for hinchey stage II?
Ia: pericolonic and phlegmonous inflammation. No abscess
Ib: has abscess
II: <5cm
What is the treatment for desmoid tumors?
Sulindac for stage I & II
Methotrexate and sorafenib for stage III
Doxorubicin for stage IV
What are the stages of desmoid tumors and their screening/rx?
Stage I: lesions < 10cm, no symptoms
- scan every year
- sulindac
Stage II: lesions < 10cm, symptoms.
- scan every 6 months
- sulindac + raloxifene
Stage III: 11-20cm
- scan every 3 months
- methotrexate, sorafenib
Stage IV: >20 cm
- scan every 6 months
- doxorubicin
Which gene accounts the most for cancer in lynch syndrome?
MSH2 (60%)
MLH1 (30%)
19F has 10 synchronous polyps in R colon and a duodenal denoma. FMHx desmoid tumors, multiple colon polyps. FAP is negative. Diagnosis?
Inheritance pattern?
Mut Y homolog associated polyposis
Autosomal recessive
In ulcerative colitis pt with high grade dysplasia, what is the risk of synchronous cancer?
40%
UC pt has dysplasia. You’re planning an operation. How do you decide between total procto + end ileostomy vs total procto + J-pouch?
Sphincter fx.
If they already have poor sphincter function, fecal incontinence, give them an ostomy
During the anal part of the APR, what structure is used as a guidance to olconne t the perineum and the pelvic dissection and separate the rectum from the levator Ani muscles?
Coccyx
After making the elliptical incision around the anus, tip the anus upward and sever it’s attachments to the coccyx. Then insert the finger into the presacral space and sweep the finger laterally to identify the levators on either side. Divide the levators as laterally as possible to avoid compromising the circumferential margins
What types of tumor risks are increases in HNPCC?
Colon, endometrial
Transitional cell cancer of the ureter Gastric cancer Small bowel Ovarian Pancreas
What’s the difference between condyloma lata vs condyloma accumunata?
Condyloma lata: secondary syphilis. flat, pale and smooth
Condyloma accumunata: HPV
Lymphogranuloma venereum
What’s the organism?
Clinical presentation?
Chlamydia
Multiple ulcers and inguinal lymphadenopathy
Anal SCC. Gets nitro. After 8 weeks in your office, mass still there. When to biopsy or watch
If the size got bigger, biopsy right away
Same or smaller -> wait until 6 months then biopsy
Horseshoe abscess.
What needs to be done?
Deep postanal space needs to be opened. Modified Hanley.
Posterior midline incision of deep postanal space with b/l counter incisions over the ischioanal fossa to drain each lateral extension of the abscess
In a healthy pt low risk for CRS cancer, how do you decide to do 10 yr colonoscopy vs 5?
First colonoscopy at what age if no family history?
If (+) adenoma, what age for first colonoscopy?
If they had ONE family member with CRS cancer, then every 5 yrs
No fam hx: 45
(+) Adenoma or more: 40 or 10 yr prior to age at family’s diagnosis
Best test to diagnose colovesical fistula?
CT - air in the bladder
T/F: Once an epidermoid anal cancer is diagnosed, a colonoscopy is mandatory due to strong association with colon cancer
There is no association between anal cancer and colon cancer.
Strictly speaking colonoscopy is not required
What is the stage II/III colorectal cancer recurrence rate with surgery/adj therapy
Up to 40%
Isolated colorectal lung metastectimy 5yr survival rate?
35-45%
What is defined as high output stoma?
What metabolic derangement do they get this this?
> 2000cc/24hr
Normal anion gap metabolic acidosis because you lose so much bicarb from the intestines
Pt with FAP undergoes total colectomy with ileorectal anastomosis. Surveillance schedule?
Lower Endo every year
Upper Endo every <4 yrs
- What is the malignant potential of Peutz Jeghers polyps?
- what is the most commonly involved portion of the GI tract in Peutz Jeghers?
- 3-6%
- jejunum and ileum are the most common sites for polyps
Villous adenomas carry what % risk for malignancy?
42%
Endoanal/endorectal advancement flaps should be avoided in what kind of pts?
Pts who already have incontinence because a small layer of circular muscle can be incorporated into the flap
LIFT is typically used for what?
Describe the two key steps
Typically for simple fistula management after primary fistulotomy failed
1) fistulotomy
2) closure of the internal opening
4 things in Amsterdam criteria
1 CRC or HNPCC related cancer under age <50
2 generations
3 family members with CRC
4 Rule out FAP
In sporadic colon cancer, what is the first and last gene mutation in the cancer pathway?
First: APC
Last: p53
Is APC a tumor suppressor or proto oncogene?
APC is a tumor suppressor gene
[T/F] lungs are the most common site of HEMATOGENOUS spread of colon cancer
False. Liver is still #1 site of heme spread. Lung is #2
What is the difference between stage IIIa vs IIIb vs IIIc colorectal cancer and the 5yr survival rates?
IIIa: N1 (3 or less nodes) + T1, T2 -> 89%
IIIb: N1 (3 or less nodes) + T3, T4 -> 69%
IIIc: N2 or more (>3 nodes) -> 53%
What is the difference between stage IIa vs IIb vs IIc colorectal cancer and the 5yr survival rates?
IIa: T3 (cancer into subserosa), N0 -> 87%
IIb: T4a (cancer has gone through all layers up to visceral peritoneum), N0 -> 63%
IIc: T4b (cancer has grown through the colon wall and is attaching to other organs), N0
C. Diff is gram [positive/negative]
[Aerobe/anaerobe]
Spore is heat [resistant/sensitive]
Gram positive anaerobe rods
Heat resistant spores
tangent: emphysematous cholecystitis also clostridium. gram positive anaerobe rods
Question gives you an old psych guy with constipation. Has explosive diarrhea in the ED. volvulus or ogilvie’s?
Volvulus because it can spontaneously detorse and have bm.
Ogilvie you won’t have spontaneous explosive bm.
5 risk factors that predict poor survival in patients with colorectal CA hepatic met
1) node positive primary tumor
2) post-op disease free survival <12 mo
3) multiple liver Mets
4) largest lesion > 5cm
5) CEA > 200
Symptomology for
- Muir Torre
- Gardner
- Turcot
- Muir Torre: sebaceous glands + CRC
- Gardner: CRC + desmoid + Mandible/skull osteoma + lipoma
- Turcot: CNS + CRC + gastric
true. doesn’t make a survival difference. but they do it anyway
what is fecal immunochemical test? why is it useful?
it is specific for hemoglobin and not influenced by other perixodase reactions. it also does not react with hemoglobin from upper GI tract. so if the blood is detected by this test, that’s specific to the colon
Crohn’s pt scheduled for an operation.
- does steroids increase post-op complications?
- does TNF inhibitor increase post-op complications?
- steroids increase post-op complications
- TNF inhibitor does not change post-op outcomes (remicade/humira/cimzia)
rectal cancer & neoadj rx
- what is the rate of complete pathologic response? is it greater or smaller than the rate of clinical response?
- if they recur, most recurn when?
- predictors of recurrence? size? nodes? CEA?
- 10-30% complete pathologic response. greater than clinical response. another 15-20% of clinical responders also have pathologic response
- most recur within the 1st year
- size is the best predictor of recurrence. nodes: no. CEA: no.
hemorrhoidectomy open vs. closed vs. stapled
- worst outcome?
- main complications and advantage with stapled?
- which one has the highest septic complication?
- open and stapled had less stenosis and less pain
- stapled has more rectal prolapse and tenesmus. stapled went back to normal activity faster
- highest septic complication: stapled
do T2 rectal tumors get neoadj?
which rectal cancers get neoadj?
T2N0 does not need neoadj
only T3+ or N1+ get neoadj
desmoid tumors. do you enucleate it or WLE?
sporadic vs. FAP desmoid difference?
WLE
sporadic desmoid 2x more common in females. FAP desmoid same in males & females
asymptomatic intra abdominal desmoid you can watch. FAP desmoid you have to cut it out
complete obstruction caused by rectal cancer 5cm from the anal verge. treatment?
no stenting for low rectal cancer
loop sigmoid colostomy is the treatment
Post-AAA ischemic colitis. Flex sig shows gray mucosa. Treatment?
Colectomy, colostomy. Not observation and abx. Gray mucosa = transmural disease
What are the measurements for toxic megacolon?
Cecum > 12cm
Colon > 6cm
Use of heparin during angiography increases the sensitivity but is associated with what complication? How frequently?
Up to 1/5 associated with ischemia if heparin used
Appendiceal tumors > 2cm are associated with what % of nodal met?
T/F: any appendiceal tumor associated even a little bit of mucin production should undergo hemicolectomy even with a negative margin and no evidence of lymphovascular invasion
30-60%
True. ANY mucin production -> hemicolectomy
Femalenwith fecal incontinence + thin perineal body. What’s the likely etiology? First treatment?
Likely obstetric tear.
Loperamide. No need for US
