COLORECTAL + ANAL Flashcards
1
Q
Left hemicolectomy - oncologic resection involves ligation of which vessels
A
Left colic vessels
If at splenic flexure, left branch of middle colics
2
Q
Li fraumeni gene
A
p53
3
Q
Lynch gene
A
MSH2
MLH1*
MSH6
PMS2
4
Q
If MLH1 is positive, what other test?
A
BRAF needs to be NEGATIVE in order to be Lynch
If positive - somatic mutation, NOT lynch!
5
Q
Lynch syndrome- high risk of what cancers
A
Colon Endometrial (esp MSH6) - can offer prophylactic TAH/BSO Stomach HPB SB Urinary tract* (diff from HAP)
6
Q
Screening Guidelines for Lynch
A
Cscope at age 20, q1-2 years
EGD at age 25 q3-5 years
Annual pelvic exam, US, and endometrial aspiration @ age 30
7
Q
Prolapse vs hemorrhoids
A
Mucosal ring vs radial folds
8
Q
Delorme Procedure
A
Stripping of mucosa from prolapsed bowel
Placating denuded muscular wall
Reanastomosing the mucosal rings
9
Q
Altemeier
A
Lonestar retractor placed at dentate line
Prolapsed segment is grasped with Babcock clamps
Score circumferential incision 1-1-1.5 cm proximal to dentate and deepen through all layers of rectal wall circumferentially
Clamp distal edge of rectum
Sharp dissection to free hernia sac, then resect sac and deliver redundant bowel
Reapproximate peritoneal edges w/absorbable suture
Enseal to seal and divide mesorectum
10
Q
Transabdominal rectopexy
A
Posterior dissection - dissect rectum out of pelvis in the total mesorectal plane until you reach levator
Pull redundancy out of pelvis
Permanent suture to peritoneum to pexy to presacral fascia
11
Q
Colovesical fistula takedown
A
Grasp sigmoid to tent up IMA and trace down to pedicle to do high ligation
Medial to lateral dissection
Free up splenic flexure
Continue down to anterior peritoneal reflection or rectosigmoid junction and transect
Proximal resection proximal to inflammatory area
Fix bladder: can backfill with dilute methylene blue, repair in 2 layers using absorbable PDS
Leak test
12
Q
Sigmoid mobilization techniques
A
Can ligate IMV just inferior aspect of pancreas (just above pancreatico-duodenal junction)
Mobilize along splenic flexure
13
Q
Wild type KRAS
A
More responsive to cetuximab
14
Q
Major AE of oxaliplatin
A
Peripheral neuropathy
15
Q
Intersphincteric fistula - tx
A
Fistulotomy
16
Q
Fistula that takes up majority of internal sphincter and 50% of external sphincter – tx
A
Draining seton
17
Q
S/p seton placement - now what?
A
Endorectal mucosal advancement flap
18
Q
Neoadjuvant chemotherapy in rectal CA
A
N+, T4, distant mets
19
Q
Anatomic def of upper rectum
A
Anterior peritoneal reflection* divides mid and upper rectum (>10 cm)
20
Q
Two oncologic reasons to perform APR
A
Unable to obtain distal margins of 1-2 cm
Invasion of external sphincter
21
Q
Lateral internal sphincterotomy
A
Prone position
2 cm radial incision at intersphincteric groove in lateral position away from hemorrhoidal tissue
Dissect into groove and isolate sphincter muscle with kelley clamp for the length of the fissure
Divide internal sphincter muscle with bovie
Close skin with 3-0 chromic
Amount divided = proportionate to fissure size
22
Q
T staging for anal SCC
A
Like breast, not colon
Based on SIZE
23
Q
Nigro protocol
A
5 FU + mitomycin C
45 Gy
24
Q
Single 1.5 cm adenoma - rescope ?
A
3 years
25
2 small <10 mm adenomas - rescope?
5 years
26
3 small <10 mm adenomas - rescope?
3 years
27
How many biopsies for UC/Crohns cscope
Minimum 33
28
Cecal diverticulitis but cecum is not inflamed and you thought it was acute appy - what do you do?
Still take out appendix
29
Utility of EUS in rectal cancer
Can help distinguish between T1 and T2 since pelvic MRI isnt as good
30
Nodular peripheral enhancement on imaging (liver)
Hemangioma
31
Central stellate scar on imaging (liver)
FNH
32
Hypervascular pattern with arterial enhancement and rapid washout (liver)
HCC
33
Hypervascular in arterial phase (liver)
hepatic adenoma
34
hypodense lesions (liver)
metastatic CRC
35
Early stage rectal CA - T and N stage
T1-2, N0
36
Locally advanced rectal CA - T and N stage
T3-T4, N0 or N+
37
"Favorable" early stage rectal CA
Full thickness excision
<3 cm, well differentiated, without LVI, within 8 cm of anal verge
Able to obtain 3 mm margins on final specimen
38
LAR - OR
Medial to lateral dissection of rectosigmoid colon starting at sacral promontory
Develop plane between RP and colon mesentery
Identify IMA** and isolate at takeoff from aorta
Be sure to ID left ureter** and then divide IMA
Continue medial to lateral dissection until reaching paracolic gutter
Mobilize splenic flexure by dividing all attachments to the colon and completely medialize descending colon
Begin TME dissection posteriorly and ID/protect hypogastric nn**
Fully mobilize rectum down to pelvic floor and ID point of transection 2 cm distal to tumor
Divide colon proximally and distally and perform stapled tension free EEA
Perform leak test and once negative, create diverting loop ileostomy at site marked preop by EST
39
Ureter injury below pelvic brim - how to fix?
Ureteral implantation into bladder
| Mobilize bladder anteriorly and facilitated by psoas hitch or boari flap
40
Anal canal - NCCN definition
begins at anorectal rim and extends to anal verge
41
Anal verge - NCCN definition
intersection of squamous-mucocutaneous junction with perianal hairbearing skin
42
SCC >5 cm from anus treated as
regular skin cancer
43
Staging imaging for anal CA
CT C/A/P +/- pelvic MRI (esp bulky anterior tumors to r/o prostate or vaginal involvement)
44
Fissures - most common location
Anterior midline
45
anal fissure - tx options
Fissurectomy
Botox 40-100 units directed into sphincter or IS space
Lateral internal sphincterotomy
Dermal advancement flap
46
Onset of botox in tx of fissures
2 weeks
47
Classic intraoperative findings of chronic anal fissure
Tear in anal canal
External skin tag
Hypertrophy of papilla
Heaped up edges of fissure
48
Hypotonic sphincter --> fissure, tx?
Anodermal advancement flap by performing fissurectomy with anodermal advancement flap over the base
49
Hemorrhoidectomy
Minimizing anoderm excised
Dissect hemorrhoidal tissue off internal sphincter
Suture ligate hemorrhoidal pedicle
Close mucosal defect with 3-0 chromic suture
Leave edge of wound open for drainage
50
Rubber band ligation - be sure to ID?
Apex of hemorrhoidal pedicle and well above dentate line
51
Horseshoe abscess and fistula - modified hanley procedure
Skin incision @ point of maximal fullness in posterior midline
Divide anococcygeal ligament
See if can pass fistula probe from this space into internal opening to see if can pass seton
Counter incisions of maximal fullness overlying bilateral ischiorectal fossa and place setons from openings to posterior midline to keep open and allow to drain
Use tonsil clamp to break up all loculations and irrigate until effluent is clear
52
Fistulotomy - OR
Divide skin and muscle overlying fistula tract
Tract + edges are debrided until there is healthy tissue
Hemostasis obtained
Wound left open
Alternatively marsupialization edges of tract to allow wound to heal from base
53
LIFT - OR
Exchanging seton for fistula probe
Make inciison externally in intersphinctic groove and dissecting out fistula tract between ext and int sphincter so that all is left is fistula probe
Suture is used to tie off ext and int tracts within sphincteric groove
Hydrogen peroxide injected into ext tract to ensure fistula has been completely disrupted
Endorectal advancement flap by dissecting out mucosal flap distal to internal opening of fistula (partial thickness of int sphincter or even full thickness)
U shaped flap extended proximally so length is 2x width
Internal tract IDed and closed with suture
Mucosal flap secured 1 cm distal to internal opening
54
colonoscopy prep
miralax split dose prep (dose day before then 3-4 hours prior to cscope) and CLD day before
NPO p MN
confirm no blood thinners or allergies
informed consent and time out
55
cscope - OR basics
start with DRE
advance scope under direct visualization to cecum as identified by appendiceal orifice, ileocecal valve and crows foot of cecum
withdraw scope spending at least 6 min on withdrawal
56
Trouble adv at splenic flexure
```
reduce any loops in scope
abd pressure from assistant
stiffen scope
switch to pediatric scope
position pt on back
incr sedation
```
57
Unable to make forward progress on c-scope
call partner
| otherwise abort procedure and get same day ct colonography
58
5 mm pedunculated polyp in transverse colon
cold snare polypectomy
59
8 mm sessile polyp in descending colon
cold snare polypectomy
60
1.5 cm pedunculated polyp in sigmoid colon
hot snare polypectomy and close mucosal defect with clips
61
when to consider tattoo in cscope
adv polyp >1 cm
62
Anal margin SCC vs anal canal SCC
If anal margin T1/T2 (<5 cm) - WLE with negative margins 1 cm
63
Anal margin SCC: T3/involve sphincter/node+/recurrence
5-fU and cisplatin
| If fails , APR
64
What else should you consider (operatively) when doing APR for pt who had prior Nigro protocol
myocutaneous flap to help with wound healing
65
APR - OR
lithotomy
laparotomy
mobilize distal colon and rectum
divide mesentery at proximal superior rectal a branch (off IMA), TME
Once you reach pelvic floor, start perineal dissection with wide dissection around levators
Place muscle flap in area of resected specimen
close perineum in layers
66
surveillance in anal SCC
q3-6 mos exams for 5 years (incl. inguinal nodes)
anoscopy q6-12 mos for 3 years
T3/T4 and any N+ also need annual CT C/A/P x 3 years
67
tx of mild c diff
PO vanco
68
tx of diarrhea + any additional signs or symptoms
Flagyl 500 mg PO TID
69
tx of c diff + either leukocytosis, hypoalbuminemia, or abd tenderness (severe c diff)
vanco 125 mg PO qid + IV flagyl
70
tx of complicated c diff
flagyl 500 mg IV TID + vanco 125 mg PO qid + vanco 500 mg in 500 mL saline as enema qid (if ileus or distended)
71
C diff - OR
Try to mark pt for ileostomy pre op
Lithotomy, proctoscopy, midline lap, colonic mobilization, transection of mesentery ( ligate ileocolic, right colic, middle colic, left colic, and sigmoid vessels), divide ileum and rectosigmoid junction, remove entire colon, bring up end-ileostomy, oversew rectal stump, irrigation, place drain in pelvis, closure of fascia and skin, mature ileostomy
72
how much anal sphincter should be preserved when doing sphincterotomy
2.5 cm
73
how to determine sphincter length
awake pt
palpate posterior anal canal, measure distance from levator ring at one's fingertip to anal verge
normal length 2-5 cm
74
how to create j pouch/ipaa
lithotomy, total proctocolectomy (divide mesentery close to bowel wall unless CA suspected), divide TI with stapler while preserving ileocolic artery, divide rectum at anorectal junction atl evel of levators with TA 30 stapler
Mobilize small bowel and mesentery (full LOA, separation of SMA pedicle from D3)
If bowel does not reach perform lengthening procedures
Make 15 cm J pouch by stapling distal 2 limbs of ileum together with GIA stapler and inserting anvil of EEA stapler and creating stapled anastomosis to anal canal
Perform diverting loop ileostomy
75
How to create length to create a J pouch (alternative options)
divide peritoneum overlying mesentery, selective ligation of mesenteric blood vessels (transilluminate to ensure colalterals)
can ligate ileocolic a
76
If crohn's is discovered when creating a J pouch?
cant do a J
| must do ileostomy
77
ways of dealing with difficult rectal stump
oversew and leave red rubber in rectum
mucus fistula
bury stump in subq so if it blows, mucus fistula can develop
78
surveillance of j pouch
yes beginning 8 years after onset of UC
79
tx of pouchitis
abx
80
most valuable tumor marker in appendiceal carcinoid
plasma chromogranin A, corresponds to tumor load
81
Pt with appendiceal carcinoid + high chromogranin A - next step?
octreoscan
| best test to find metastatic disease
82
Appendiceal carcinoid >2 cm, incomplete resection, evidence of metastatic disease or goblet cell tumors warrant what additional testing
```
plasma chromogranin A levels
CT scan abd/pelvis
24 hr urine 5-HIAA
octreotide scintigraphy
Need to assess rest of GI tract with EGD/cscope and capsule endoscopy to r/o other GI tumors
```
83
What size appendiceal carcinoid do not require staging?
if <1 cm unless high-grade and/or malignant
84
appendiceal mucinous tumor involving base of appendix - tx?
cecectomy
85
who gets adjuvant tx in rectal CFA
pT3, pT4, or any N+
86
who gets neoadjuvant therapy in rectal CA
T3 or any N
87
What is preferred total neoadjuvant therapy
```
FOLFOX 12-16 weeks
Then long course chemo/RT with infusional 5-FU
then restaging (8 weeks after completion)
```
88
Colon CA at splenic flexure - which vessels
L colic
L branches of middle colic
IMV
89
Minimum LN in colon CA
12
90
Left hemicolectomy (colon CA)
ex lap with transection of IMV at level of ligament of treitz
transect left colic a at level of origin from IMA
complete medial to lateral mobilization of splenic flexure of colon
transect white line of toldt
transect splenocolic, gastrocolic ligaments
stapled transection of colon with 5 cm margins
colo-colonic anastomosis
91
which artery should be ligated when tumor is distal to mid-transverse colon
ascending branch of left colic
92
obstructing transverse colon CA - OR approach
- Prophylactic antibiotics and subcutaneous heparin
- Low lithotomy
- Midline laparotomy (examine the entire cavity looking for mets)
- Decompressive colotomy of proximal R colon can make the procedure easier (prior to this, place a purse string suture around a suction)
- Mobilize R colon from lateral to medial to the level of anterior D2
- Enter lesser sac at hepatic flexure
- Remove the greater omentum from the stomach since it is a TRANSVERSE colon cancer
- Mobilize the splenic flexure
- Divide the mesentery, ligating ileocolic, middle colic, and ascending branch of the L colic a (ascending branch is ligated when the tumor is distal to the mid-transverse colon)
- Construct ileocolic anastomosis distal to splenic flexure (unless the patient is hemodynamically unstable or there is gross feculent peritonitis needing stoma) in descending colon due to concerns for watershed blood supply
- Hand sewn end-to-end with inner layer of running absorbable 3-0 and outer 3-0 interrupted silks → to manage size discrepancy, can enlarge small bowel and “bevel” the aperture along the antimesenteric side of intestine
- Can also do stapled side-to-side/functional end-to-end anastomosis
- Close mesenteric defect
- Irrigate and close the abdomen
93
Extended R hemicolectomy - OR
Start medial--> lateral dissection and perform high ligation of ileocolic pedicle and right colic artery after clearly identifying duodenum
medial to lateral dissection of ascending colon taking care to protect kidney, ureter, duodenum, in RP plane
Incise white line of Toldt laterally and take down gastrocolic ligament to enter lesser sac
Needs dissection and division of middle colic vessels (ext right)
once completely mobilized, extracorporalize specimen and divide ileum 5 cm proximal to ileocecal valve and colon near splenic flexure
tension free stapled SSA ileocolic
94
Surveillance in colon CA
H&P q3 months x 2 years then q6mo x 5 years
CEA q3 months x 2 years then q6mo x 5 years
CT C/A/P q6months x 5 years
Colonoscopy at 1 year
95
UC - findings (endoscopic and histologic)
continuous inflammation, starting @ rectum
| superficial lymphoid aggregates, crypt abscesses
96
Crohns - findings (endoscopic and histologic)
skip lesions, involvement of TI, cobblestone edema, apthous and deep ulcers, strictures
granulomas, transmural inflammation
97
IPAA - ileal pouch wont reach anus. Pouch lengthening maneuvers?
Ensure small bowel mesentery fully mobilized off RP all the way to LoT and 4th portion of duo
Perform high ligation of ileocolic pedicle
Assess diff sections of TI as best point of apex for pouch in terms of reach
IF still wont, can make relaxing incisions on both sides of SB mesentery perpendicular to vessels
If still wont, selectively divide mesenteric arcade
Create S shaped pouch or leaving defunctioning J pouch with plans to reoperate in 6 months
98
Elderly man with LUQ pain and bloody BM - next steps
Adequate IV access
CBC, CMP, lactate
Stool studies to r/o infectious etiologies
If Cr ok, can get CT A/P
99
Mild c diff definition
WBC < 15 AND Cr < 1.5
100
Severe c diff definition
WBC > 15 AND/OR Cr >1.5
101
Fulminant c diff colitis definition
Hypotension, septic shock, ileus, megacolon, or need for ICU
102
Toxic colitis definition
Colon dilation
103
Sigmoid volvulus - flex sig OR
Propofol sedation
Introduce scope under direct visualization through anus and rectum
Minimal insufflation of CO2 until reach area of narrowing and twisting
Gently advance until reach dilated colon proximally
Suck out as much gas and stool proximally as possible
Leave decompressive rectal tube
104
Diverticulitis - OR (not super sick)
Midline laparotomy
Washout abdomen thoroughly
Mobilize descending colon and splenic flexure, taking care to identify ureters
ID transection margins; proximal would be distal most margin of healthy uninvolved colon and distal margin proximal rectum; then perform tension free colon to rectal EEA
Sigmoidoscope for leak test
Diverting ileostomy
105
1-2 tubular adenomas found on cscope - when to repeat?
5-7 years
106
3 tubular adenomas found on cscope - when to rescope?
3 years
107
Single adenoma >10 mm with tubulovillous, villous or high grade dysplasia - when to rescope?
3 years
108
If >10 adenomas found, when to rescope?
1 year
109
Ostomy triangle
ASIS
umbilicus
pubic symphysis
110
End Ostomy OR
Clamp skin with kochers and remove 3 cm disk of skin
Protect bowel by placing sponge deep to peritoneum and anteriorly on the abdominal wall
Divide through fascia with cautery and spread apart the rectus muscle
Divide posterior sheath longitudinally
Distal aspect of intestine oriented to ensure mesentery isnt twisted and a babcock is passed through trephine and intestine is brought through to the skin without tension
Place sutures full thickness from mucosa to serosa
Sutures passed through subq layer
111
Loop ostomy OR
Sutures of differing colors can mark proximal and distal limbs
Create window in mesentery adjacent to bowel and pass umbilical tape through the opening
Grasp ends of umbilical tape through trephine and exchange tape for ostomy rod
Distal aspect opened transversely leaving posterior wall intact
Sutures full thickness through bowel and into the dermis - first distal, then proximal
