colorectal Flashcards
(176 cards)
1
Q
what is the lymphatic drainage of the rectum?
A
upper–↑ inferior mesenteric LN
middle–↑ inferior mesenteric LN
lower– internal iliac LN← ↑ →internal iliac LN
2
Q
what is the lymphatic drainage of the anus?
A
← ↑ → ---------------------- [DENTATE LINE] ---------------------- Inguinal LN & ← ↑ →
3
Q
describe Colorectal and Anorectal Nerve Supply
A
Sympathetic (inhibitory) : T6-L3
Parasympathetic (stimulatory):
1. ↑→ : Vagus
2.↓ : S2–S4
external anal sphincter &puborectalis: int. pudend.
levator ani: int. pudend.+ S3-S5
anal canal (below dentate line) sens: int. pudend.
4
Q
what is Proctalgia fugax?
A
Anorectal pain results from levator spasm and may present without any other
anorectal findings.
5
Q
what to do in LOWER GI BLEEDING?
A
- ABC
- identify the source:
* NG aspiration: if blood / nonbile →EGD
else: distal to the ligament of Treiz
* Anoscopy +- limited proctoscopy: hemorrhoidal bleeding
* 99mTc-tagged RBC scan (0.1 mL/h) then angiography
* Colonoscopy if stable and prepare over 4-6h - intervention
* endoscopy
* angiography
* if fail, Colectomy
* if unstable and unknown, proctoscopy then blind subtotal colectomy
6
Q
what are the ddx for Hematochezia?
A
- Hemorrhoids: painless and bright red w/bowel move(anoscopy)
- Fissure: sharp pain and bright red w/ bowel move
- Others: DRE→ proctosigmoidoscopy→colonoscopy
7
Q
what are the characteristics of collitis?
A
- abd pain
2. bloody diarrhea
8
Q
define chronic diarrhea
A
a decrease in stool consistency for more than 4 wks
9
Q
what are the ddx for chronic diarrhea?
A
- watery-secretive
- osmotic
- functional - malabsorptive(fatty)
- inflammation
10
Q
what is the Rome III criteria for IBS?
A
recur abd pain or discomfort & bowel habits >= 6mo , with sx >= 3 d/mo for >= 3mo. >=2 of following :
- Pain is RELIEVED by a bowel movement
- Onset of pain is related to a change in FREQUENCY of stool
- Onset of pain is related to a change in APPEARANCE of stool
11
Q
what further evaluation should be done if a healthy young patients meeting Rome III criteria and responsive to therapy?
A
Screening for celiac disease and iron deficiency anemia
12
Q
what are the indications for emergent resection?
A
- obstruction,
- perforation,
- hemorrhage
13
Q
what are the surgical principles for emergent resection?
A
segment+lymphovascular
If Rt or prox. trans.:
if healthy bowel & stable:
primary ileocolonic anastomosis
If Lt:
if healthy bowel & stable:
end colostomy +-mucus fistula
else:
subtotal colectomy + ileosigmoidostomy
or
resection and diversion
14
Q
what are indications for total colectomy or subtotal colectomy?
A
- fulminant colitis
- attenuated familial adenomatous polyposis
- synchronous colon carcinomas
15
Q
define Restorative proctocolectomy
A
total proctocolectomy + ileoanal pouch
preservation of the anal sphincters
16
Q
define Anterior Resection
A
resection of the rectum from an abdominal approach
17
Q
define High Anterior Resection
A
resection of the distal sigmoid + upper rectum (benign lesions at the rectosigmoid
junction)
18
Q
define Low Anterior Resection
A
remove lesions in the upper and mid
rectum
19
Q
define Extended Low Anterior Resection
A
remove lesions located in the distal rectum(cms above the sphincter)
20
Q
what is the complications of coloanal anastomosis?
A
- anastomotic leak & sepsis
2. poor function and continence
21
Q
define Hartmann pouch
A
without an anastomosis, distal colon or rectum is left as a closed off blind pouch
22
Q
define Mucus Fistula
A
opening the defunctioned
bowel and suturing it to the skin (if long enough)
23
Q
define Abdominoperineal Resection
A
removal of the entire rectum, anal canal,
and anus with construction of a permanent colostomy from the descending or
sigmoid colon
24
Q
what will the stoma be placed?
A
1.within the rectus muscle to minimize the risk of a postoperative parastomal
hernia
2.where the patient can see it and easily manipulate
the appliance
3.surrounding abdominal soft tissue should be as flat as
possible to ensure a tight seal and prevent leakage
25
what kind of anastomosis is at risk of leakage?
1. low in the rectum
2. in an irradiated field
3. immunocompromised
4. malnourished
5. emergency operation
26
what are the complications of Ileostomy?
1. anatomical:
- stoma necrosis
- stoma retraction
- skin irritation
- obstruction
- parastomal hernia(
27
what is the most common late complication of a colostomy?
Parastomal hernia (resiting on the CONTRALATERAL side)
28
what is the most commonly used regimen of Antibiotic prophylaxis before bowel surgery?
neomycin(1g)x3+erythromycin(1g)/metronidazole(500mg)
| ciprofloxacin
29
what are the pathologic and endoscopic features of UC?
MUCOSAL atrophy, crypt abscess, infiltrate;
| friable, granular, pseudopolyps, rectum to colon
30
what are the pathologic and endoscopic features of UC?
TRANSMURAL, mucosal ulcer, infiltrate, noncaseating granuloma, fibrosis;
deep serpiginous ulcers, "cobblestone", skip lesions, rectal sparing
31
what are some ddx of IBD?
* ischaemic colitis
* infectious [Campylobacter jejuni, Clostridium difficile, Entamoeba histolytica, Salmonella, Shigella, Neiserria gonococcus]
32
list some Extraintestinal Manifestations of IBD
1. Hepatic: fat, PSC, bile ca, cirrhosis
2. Joint: arthritis, sacroiliitis, ankyl.spon.
3. Skin: erythema nodosum, pyoderma gangrenosm
4. Eye: uveitis, iritis, episcleritis, conjunctivitis
33
when will you use salicylate and/or cs suppositories or enema?
ulcerative proctitis, proctosigmoiditis
34
first-line agents for mild to moderate IBD
sulfasalazine, 5-ASA, mesalamine
35
Abx should be used to treat UC
NO(except fulminant colitis or toxic megacolon)
| instead, abx is used in CD
36
List some immunosuppressive agents for IBD
AZA/6MP(+cs), Cyclosporine(acute flare), MTX, Infliximab(mod to sev CD)
37
apart from drugs above, what else should be considered?
parenteral nutrition
38
what if stricture is diagnosed in a patient with UC?
presumed to be malignant until proven otherwise
39
fulminant colitis definition
*Clinical dx [>10 stools, continuous bleed, abd pain, distention, fever] → toxic megacolon
40
toxic megacolon definition
*Radiographic dx[colon>=6cm/caecum>9cm+systemic toxic sx]
41
Indications for surgery in UC
* Emergent
- life bleed,
- fulminant colitis despite meds24h,
- toxic megacolon
* Elective(total proctocolectomy+end ileostomy)
- meds fail,
- meds se,
- dysplasia
42
proctocolectomy for fulminant colitis/toxic megacolon(emergent)
total abdominal COLECTOMY with end ileostomy is recommended
∵[1]improve after
∵[2]difficult & time-consuming
43
what if patients who require total proctocolectomy
| wish to avoid a permanent ileostomy
Restorative proctocolectomy with ileal pouch–anal anastomosis
44
how many CDs are rectal-sparing
40%
45
Indications for Surgery in CD
IF COMPLICATIONS → segment resection
*Acute inflammatory phase+fistulas/abscess:
bowel rest, anti-inflammatory meds, abx, drainage, nutrition
→ segment resection
*Chronic fibrosis:
-stricture(resection/stricturoplasty),
-fistulas(resection of active one)
46
CD common involved sites
terminal ileum and cecum>small bowel> colon and rectum
47
what Ileal pouch–anal reconstruction is not recommended in CD colitis
pouch CD & failure
48
why skin tags and hemorrhoids are not excised in CD?
[unless extremely symptomatic]
| ∵ creating chronic, nonhealing wounds.
49
why sphincterotomy is in CD relatively contraindicated?
∵[1]chronic, nonhealing wounds.
| [2] incontinence ← diarrhea
50
why choose stoma over anastomosis?
1. unstable
2. malnourished
3. immunocompromised
4. septic
5. intraabd contamination
51
Risk of recurrence after resection for ileocolic
| and small-bowel CD
>50% w/n 10yrs
52
how many CD patients have Anal or perianal disease?
35%
53
The most common perianal lesions
| in Crohn disease are
skin tags
54
what are the characteristics of perianal abscesses and fistulas in CD?
1. Recurrent abscesses
| 2. Complex fistular tracts
55
how to delineate complex anal fistulas?
Endoanal us & Pelvic MRI
56
how to treat anal fistulas in CD?
1. Setons(maintain drainage and/or induce fibrosis;non-division of the sphincter)
2. Endoanal advancement flap (definitive if rectal mucosa intact)
57
what will be the next step if perianal sepsis is intractible(10-15%)?
protectomy
58
what is the is the primary goal
| of therapy in anal and perianal CD?
1.control of sepsis (Metronidazole),
2.delineation of complex
anatomy,
3.treatment of underlying mucosal disease,
4.sphincter preservation.
59
drain abscesses before or after immunosuppressive therapy?
before
60
which agent improves chronic anal fistulas in CD?
Infliximab
61
what is the incidence of Indeterminate Colitis in IBD?
15%
62
Indications for surgery in Indeterminate Colitis
same as UC
63
Procedures for Indeterminate Colitis
```
total colectomy+end ileostomy
▽
PATHOLOGY DX of ENTIRE COLON
▽
elective proctectomy +- reconstruction
```
64
how many people with diverticulosis will have diverticulosis?
10–25%
65
the most common site of diverticulosis
The sigmoid colon
66
what is the treatment of uncomplicated diverticulitis?
Broad-spectrum abx po + a low-residue diet
or
abx iv + bowel rest
improves w/n 48-72hrs
67
what is the treatment of recurrent diverticulitis?
elective sigmoid colectomy +primary anastomosis often is recommended after the 2nd episode of diverticulitis
68
in what situation will resection be needed in 1st episode of diverticulitis?
- young patients
- immunosuppressed patients
- complicated diverticulitis
69
is resection of all diverticula required?
unnecessary; The resection should always
| be extended to the rectum distally +all thickened or inflamed bowel proximally
70
Complicated diverticulitis includes
diverticulitis with
1.abscess,
2.obstruction(67%),
3.diffuse peritonitis (free perforation),
4.fistulas between the colon and adjacent
structures(5%)
71
Hinchey staging system
used to describe the severity
of complicated diverticulitis:
Stage I – colonic inflammation w/ a PERICOLIC abscess
Stage II – colonic inflammation w/ a RETROPERITONEAL or PEVIC abscess
Stage III – PURRULENT peritonitis
Stage IV – FECAL peritonitis
72
treatments for stage I&II
sigmoid colectomy +primary anastomosis
73
treatments for stage III&IV
sigmoid colectomy with end
| colostomy and Hartmann pouch
74
mobilization of the sigmoid colon w/ inflam&phlegmon will damage which structure?
ureter
75
what will prevent ureteral damage?
preoperative placement of ureteral
| catheters
76
complicated diverticulitis develop
| fistulas between colon &
Colovesical>colovaginal and coloenteric
77
ddx of fistulas between the colon and adjacent
| structures
- Complicated diverticulitis
- Tumor,
- CD
- RT
78
Two key points in the evaluation of fistulas
1. anatomy (contrast)
| 2. exclude dx (CT)
79
no f/u needed after resolution
| of the acute diverticulitis
false
Sigmoidoscopy or colonoscopy is recommended
4–6 weeks after recovery to exclude malignancy.
80
what is a major ddx of diverticulitis?
colon carcinoma
81
what to suspect in older patients w/massive lower GI bleeding?
1. diverticulosis
| 2. angiodysplasia
82
what are the risk factors of Colorectal carcinoma
1. Aging(50y)
2. Hereditary
3. Lifestyle: Diet
4. Cigarettes(35yrs→ colonic adenomas)
5. Pelvic irradiation→ rectal ca
6. Colitis-IBD
7. Ureterosigmoidostomy→adenoma&ca
8. Acromegaly
83
how many patients w/ Colorectal carcinoma have a known family history of colorectal cancer?
20%
84
describe the genetic pathways of Colorectal carcinoma
1. LOH (loss of heterozygosity) pathway (80%)
- APC (suppressor)
- p53
- K-ras (proto-)
- DCC (suppressor)
2. RER (replication error) pathway(20%)
[hMSH2, hMLH1, hPMS1, hPMS2, and hMSH6/GTBP]→microsatellite instability (MSI)
85
types of colorectal polyps
1. neoplastic (tubular-villous-tubulovillous)
2. hamartomatous (juvenile, Peutz-Jeghers, Cronkite-Canada)
3. inflammatory (pseudo, benign lymphoid)
4. hyperplastic
86
what factors are associated with highest risk of malignant degeneration in colorectal adenoma?
1. type-villous
| 2. size-2cm
87
how to remove colorectal polyps?
1. pedunculated-snare
2.sessile-saline lift/piecemeal
[site marked for f/u]
3.large, flat/invasive→colectomy
88
Complications of polypectomy
1. perforation
| 2. bleeding
89
symptoms of Hamartomatous polyps
1. bleeding
2. intussception
3. obstruction
90
location of polyps in Familial juvenile polyposis
colon, recutm
91
how to screen Familial juvenile polyposis?
since 10-12 y annually
92
are polyps in Familial juvenile polyposis premalignant?
Unlike solitary juvenile polyps, they are premalignant
| Treatment is surgical.
93
which part of GI tract does Peutz-Jeghers syndrome involve?
small intestine>colon,rectum
94
what is the screening plan of Peutz-Jeghers syndrome?
20y: baseline upper + lower endoscope
then: flexible sigmoidoscopy per y
95
indications of surgery in Peutz-Jeghers syndrome
1. bleeding
2. obstruction
3. adenoma
96
describe Cronkite-Canada syndrome
1. GI polyposis
2. alopecia
3. cutaneous pigmentation
4. atrophy of fingernails/toenails
97
what symptoms may Cronkite-Canada syndrome have?
1. DIARRHEA
2. vomiting,
3. malabsorption,
4. protein-losing enteropathy
98
indications of surgery in Cronkite-Canada syndrome
if complications of polyposis occur
99
what are the typical features of Cowden syndrome?
1. gastrointestinal polyps
2. facial trichilemmomas,
3. breast cancer,
4. thyroid disease
100
should Inflammatory Polyps be removed?
yes, because they cant be differentiated from adenomas by appearance
101
The lifetime risk of colorectal cancer in FAP
100% by 50y
102
screening of FAP
```
*APC gene mutation testing (if present)
if testing "+":
annual flex. sigmoid. from 10-15y
else:
treat as "average-risk"
*Upper endoscopy from 25-30y q 1-3 y
```
103
apart from colorectal ca, which ca is of particular concern in FAP?
periampullary ca in duodenum
104
what agents might be used to treat FAP?
COX-2 inhibitors (celecoxib, sulindac)
105
Gardner syndrome features
1. FAP
2. Osteomas, soft tissue (eg. desmoid)
3. REtinal pigmented epithelium hypertropy
4. Supernumerary Teeth
106
Turcot syndrome features
1. FAP
| 2. CVS tumors (eg. medulloblastoma)
107
how is attenuated FAP different from FAP?
1. present later, develop later
| 2. fewer polyps (10-100)
108
what is the treatment for attenuated FAP
total abd colectomy + ileorectal anastomosis
| +- snare in rectum
109
screening plan for attenuated FAP
13-15y → q 4 y →28y→ q 3 y
110
at what age do patients with HNPCC develop colorectal ca?
70% will at 40-45 y
111
what other extracolonic tumors may HNPCC be associated with?
- endometrial, ovarian
- pancreas, stomach, small bowel, biliary
- urinary tract
112
Amsterdam criteria for clinical dx of HNPCC:
* 3 affected relatives (one 1st degree of one of the others)
* 2 successive generations
* 1 diagnosed before 50y
113
screening for HNPCC
* 20-25y or 10yrs younger: colonoscopy annually (colorectal ca)
* 20-35y transvaginal US / bx annually (endometrial ca)
114
The risk of developing a synchronous/metachronous colon cancer in HNPCC
40%
115
what is the treatment of HNPCC?
* total colectomy + ileorectal anastomosis (annual proctoscopy)
* prophylactic TAH+BSO (childbearing completed)
116
screening in familial colorectal cancer
40y then q 5 y / 10 yrs prior then q 5 y
117
how is CT colonography compared to colonoscopy?
same sensitivity if polyp or cancer >1cm;
| but still need colonoscopy
118
most common form of spread of colorectal ca?
regional LN
119
which factor predicts most of LN spread of colorectal ca?
T stage(depth of invasion)
120
most common site of distant metastasis from colorectal ca
liver
121
the classic early sx of colorectal ca
1. change of bowel habit
| 2. rectal bleeding
122
single most important prognostic factor in colorectal carcinoma
node involvement
123
T stage of colorectal ca
T1 submucosa
T2 muscularis propria
T3 subserosa / nonperitonealized pericolic or
perirectal tissues
T4 directly invades other organs/tissues/perforates the visceral peritoneum of specimen
124
N stage of colorectal ca
N1 1-3 pericolic or perirectal LN
N2 >=4 pericolic or perirectal LN
N3 any LN along a major named vascular trunk
125
TNM Staging of Colorectal Ca
I T1–2, N0, M0 70–95%
II T3–4, N0, M0 54–65%
III Tany, N1-3, M0 39–60%
IV Tany, Nany, M1 0–16%
126
chemo for Colorectal Ca
stage II-IV adjuvant:
| 5-Fluorouracil–based regimens (with levamisole or leucovorin)
127
how is the Principles of Resection of rectal ca different from that of colon ca?
1. different approach (pelvic structures)
2. difficult "-" margins → higher local recurrence→adjuvant
3. RT
128
what is TEM?
Transanal endoscopic microsurgery for local
| excision of lesions higher in the rectum (up to 15 cm)
129
Transanal excision (full thickness or mucosal) is indicated for
noncircumferential, benign, villous adenomas of the rectum (1cm margin should be obtained )
130
curative resection margin for rectal ca
2-cm, distal mural margin
131
what is TME?
Total mesorectal excision:
| sharp dissection → complete resection of the rectal mesentery
132
Benefits of TME
1. ↓ recur
2. ↓bleed
3. ↓damage to nerves
133
pelvic exenteration is indicated if
Extensive involvement of other pelvic organs (often in the presence of recurrent
cancer)
134
f/u of colorectal ca
* colonoscopy 12mo then q 3-5 y
| * CEA q 2-3 mo for 2yrs → CT
135
risk of Recurrent Colorectal Carcinoma
20-40% of patients who have undergone curative intent
| surgery
136
when do most recurrences of Colorectal Carcinoma occur?
w/n the first 2 yrs
137
what is Bowen disease?
squamous cell carcinoma in situ of the anus
138
Risk factors of anal intraepithelial neoplasia (AIN)
HPV 16, 18
139
f/u investigation after resection/ablation of AIN
Anal Pap Smears
↓ if abnl
anoscopy+bx+ablation
140
Epidermoid carcinoma of the anus includes
1. squamous cell,
2. cloacogenic
3. transitional
4. basaloid
141
Rx for Epidermoid ca of the anus
*Anal margin: wide local excision
*Anal canal(/invading sphincter): the Nigro protocol
if recur: APR
142
Nigro protocol
```
chemoradiation (1st line ) for anal canal epidermoid ca
includes:
-RT
-5-FU
-Mitomycin
```
143
features of Verrucous ca of the anus
1. locally aggressive →destructive
2. not metastasize
3. indistinguishable from epidermoid ca
144
what's the difference between colonic ischemia and small bowel ischemia?
COLON: more common, low flow+-small vessel occlusion
| SMALL BOWEL: less common, major arterial/venous occlusion
145
define Hemorrhoids
cushions of submucosal tissue containing [venules+arterioles+ smooth-muscle fibers] that are located in the anal canal.
146
locations of Hemorrhoids
\_
| /
147
indications of treatment for Hemorrhoids
Sx eg. bleed, prolapse, pain (nl anatomy)
148
Grades of internal hemorrhoids
1st degree: anal canal
2nd degree:anus, spontaneously
3rd degree: anus, manual
4th degree: anus, X reduced
149
Treatments of Hemorrhoids
* 1st , 2nd
- Medical Therapy (diet, fluid, X strain, sitz baths, analgesics )
- Rubber Band Ligation, sclerotherapy, infrared photocoagulation
*3rd, 4th
Elective Operative hemorrhoidectomy
150
the rationale of Operative hemorrhoidectomy
1. reduce blood inflow
| 2. remove redundant anoderm and mucosa
151
how long will the sx of Acutely thrombosed external
| hemorrhoids last w/o excision?
72hrs
152
Complications of hemorrhoidectomy
* short-term:
1. pain
2. urinary retention
3. fecal impaction
4. bleed: exam and ligate
5. ifx: drain, debride
* long-term:
1. incontinence
2. anal stenosis
3. ectropion
153
where do Most anal fissures occur?
post. midline>ant.mid(10-15%)>off mid(<1%)
154
what are the ddx if a chronic anal fissure is laterally located?
- Crohn's Disease
- HIV, syphilis, tuberculosis
- Leukemia
155
what are the characteristics of a chronic anal fissure?
1. ulcer
2. heaped-up edges
3. white base
4. ext.skin tag+-int.hypertrophied papilla
156
how to treat anal fissures?
* MEDICAL
1. Diet
2. Topical: lidocaine, GTN, diltiazem, nifedipine
3. Botox
* SURGICAL
1. Lateral internal sphincterotomy (minor incontinence)
2. fissurectomy, anal advancement flap
157
aims of anal fissure treatment
breaking the cycle of pain, SPASM, and ischemia
158
where are Anorectal abscesses (Cryptoglandular Abscess) located?
1. perianal
2. intersphincteric
3. ischiorectal
4. supralevator
159
what is the most serious complication of Anorectal abscesses ?
Sepsis
160
how to drain Supralevator Abscess?
1. find the origin
- intra-abd
- ischiorectal
- intersphincteric
2. drain
161
what causes Fistula in Ano
persistent, unresolved Anorectal abscesses (Cryptoglandular Abscess)
162
Goodsall rule
to predict course of Fistula in Ano
* ANT to trans anal line: short and radial tract
* POST to trans anal line: curved to post. midline
163
The goal of treatment of fistula in ano
1. treat sepsis
| 2. preserve continence
164
types of fistula in ano
1. Intersphincteric
2. Transsphincteric (ischiorectal abscess)
3. Suprasphincteric
4. Extrasphincteric
5. Complex, nonhealing fistula
165
treatment of Intersphincteric fistula
fistulotomy + curettage + secondary intention
166
treatment of Transsphincteric fistula
if <30% sphincter:
sphincterotomy
else:
seton
167
treatment of Suprasphincteric fistula
seton
168
treatment of Extrasphincteric fistula
- Extrasphincteric portion: open and drain
| - complex: drains and setons
169
treatment of Complex, nonhealing fistula
1. Proctoscopy to access health rectal mucosa;
2. Biopsy of fistula tract to rule out malignancy
3. setons, endorectal advancement flap, fibrin glue
170
rectovaginal fistula
between the vagina and the rectum
| or anal canal proximal to the dentate line
171
classifications of rectovaginal fistula
1. Low: fourchette
2. Mid: fourchette-cervix
2. High: cervix
172
causes of rectovaginal fistula
1. obstetric injury
2. rectal surgery
3. radiation
4. undrained abscess
5. complicated diverticulitis
6. CD
7. malignancy
173
how to treat obstetric rectovaginal fistula?
1. wait for 3-6mo (heal spontaneously)
| 2. endorectal advancement flap (low/mid); transabd (high)
174
which rectovaginal fistulas should be biopsied?
rad-caused and malignancy
175
when an immunocompromised patient presenting with neutropenia (<1000)/ and RIF pain
consider Neutropenic enterocolitis (typhlitis)--mortality>50%
176
the aim of radical surgery for rectal cancer
1. achieving cure
2. avoiding loco-regional recurrence
3. avoid permanent colostomy
4. maintain adequate anorectal function
5. avoid autonomic nerve dysfunction
