Anal Disease Flashcards
How do you identify the dentate/pectinate line? Above = internal hem, Below = external hem
Anal valves and bases of anal columns. Microscopically, transitions from mucocutaneous junction between nonkeratinizing squamous mucosa and keratinizing squamous epithelium.
Innervation: SOMATIC below, AUTONOMIC above.
What is the arterial blood supply to the anal region?
Proximal (above dentate) = superior rectal artery / superior rectal vein (IMV) and middle rectal vein (iliacs)
Distal = inferior rectal branch of PUDENDAL artery / inferior hemorrhoidal vessels (iliac)
What is the lymphatic drainage of the anal region?
Proximal (above dentate) = mesorectal, internal iliac, inferior mesenteric nodes
Distal = inguinal nodes
What is the incidence of anal cancer?
2.6% of GI malignancies.
Histologic variants of anal squamous neoplasms?
Cloacogenic
Basaloid
Epidermoid
Mucoepidermoid
All need Nigro.
Main HPV variants that cause anal squamous cell carcinoma?
16 and 18.
What is condyloma acuminata?
Anal warts. Mostly 6 and 11. Flesh colored papules that itch.
How do you treat condyloma acuminata?
Imiquimod cream, podophyllotoxin, 5-FU, sinecatechins clear to 40-60% especially in smaller lesions.
If fails, try 80-90% trichoroacetic acid TCA (in office), cryotherapy, or fulguration/excision.
If very large, surgical excision.
if > 50% circumference, need to stage to avoid stenosis
What is the recurrence rate of condyloma after treatment?
20-40%.
What is Buschke-Lowenstein tumor?
Verrucous carcinoma or giant condyloma acuminatum; with very high risk of fistula/abscess formation. Spreads laterally (doesn’t really metastasize). HPV 6, 11. Treat with WLE.
What is the Bethesda classification in the setting of AIN?
ASCUS, LSIL (AIN I), HSIL (AIN II/III), atypical squamous cells that cannot exclude HSIL.
What cyclin dependent kinase inhibitor is overexpressed in HPV associated carcinogenesis?
P16
How do you screen for anal SCC in high risk population?
Annual anal pap smear with high resolution anoscopy (with 3% acetic acid solution or Lugol’s) for ASCUS or dysplasia.
How do you treat LSIL?
Nothing, can just surveillance q3-6 mos with pap +/- HRA
How do you treat HSIL?
Topical 5% Imiquimod
Topical 5% 5-FU
TCA
should be adjuncts to photodynamic therapy, RF ablation, infrared coagulation, electrocautery.
What is superficially invasive squamous cell carcinoma of the anus?
Minimally invasive SCC that is completely excised with 3mm or less basement membrane invasion and 7mm or less horizontal spread.
How often does anal SCC spread?
32% nodal, 13% metastatic.
Workup of anal mass?
DRE/anoscopy/BIOPSY, FNA of lymphadenopathy, CT CAP for staging, MRI for locoregional disease
What is the Nigro protocol?
5-FU , mitomycin C, 30 Gray radiation x 3 weeks.
How successful is Nigro protocol?
80-90% for locoregional disease.
What chemotherapeutic do you consider to add to 5-FU for metastatic anal SCC?
Cisplatin.
When is surgery indicated for anal SCC?
Locoregional recurrence/persistence after Nigro protocol, after 6 months. Surgery of choice is salvage APR (5 yr overall survival 25-60% compared to 3%)
What is the surveillance after Nigro protocol?
DRE/anoscopy q3-6 months x 5 years; add panscan if nodal disease present or above T3 primary lesion.
How to treat T1 well-differentiated perianal SCC that you can pull out of anus easily ?
WLE 1 cm margins alone.
anal SCC (but of anal margin, not canal) mgmt
WLE < 5 cm with 5m margin
otherwise > 5cm gets chemoXRT 5FU cisplatin (not mitomycin) or if involving sphincter or positive nodes
anal BCC of margin
just 3mm margin is ok to avoid APR (rarely touches sphincter)
How to treat anal adenocarcinoma?
WLE w/ 2-3 mm margins for T1 (<4cm, <1/2 circumference) well differentiated. Or APR with adjuvant chemoXRT like rectal ca
What glands are anal adenocarcinomas from?
Upper glandular anal cells like columnar epithelium (like low rectal adenocarcinoma), anal glands, chronic fistula tracts.
What kind of cells are malignant in extramammary Paget’s disease of the perianal region?
Large rounded vacuolated Paget cells (arising from apocrine glands or metachronous lesion from another site) causing an intraepithelial adenocarcinoma. Look for concurrent CRC or GU malignancy.
How to treat extramammary Paget’s disease?
WLE 1 cm margin with (myo)cutaneous flaps; if locally invasive may need neoadjuvant chemoradiation with APR.
How does anal melanoma present?
Bleeding and pain. Pigmented lesions may look like thrombosed hemorrhoids. (30% amelanotic)
Is the prognosis good or bad for anal melanoma?
Bad.
How to treat anal melanoma?
WLE, or if extensive sphincter involvement will need APR.
How to treat anal NET?
WLE, or if very large locally advanced tumors will need radical resection.
How to treat anal lymphoma (HL and NHL)?
Chemoradiation (usually high grade B cell lymphoma).
perianal nerve block
ischioanal fossa -
ischial spine is palpated, needle is advanced towards the ischial spine.
Local anesthetic is administered about 2.5 cm posteromedial to the ischial tuberosity
fissure tx
- NOM: fiber, sitz, topic anesthetic > nitrates (AE: HA), CCB (no HA - similar efficacy)
- Botox (AE: incontinence//CI!)
- LIS (CI: childbearing, prior OB injury, IBD, hx incontinence) vs anocutaneous flap (+/- LIS, botox)
LIS = laternal internal sphincterotomy; along entire length of the FISSURE
incont after lat int sphincteroyomy?
8-30% will have
hemorrhoid mgmt
int:
conservative first
banding I & II
sclerotherapy if bleeding risk (on AC) I & II
excisional III & IV
ext thrombosed:
<72 hrs - excise
>72 hrs - conservative (or lance open)
perianal I&D target
as close to anal verge as possible
incont 2/2 sphincter thinness post vag delivery ie
get endoanal us to dx then:
phincter overlp or sacral N stim
heomorrhoidal plexuses
- left lateral
- right anterior
- right posterior
anorectal abscess location
- perianal MC
- intersphincteric
- ischiorectal
- supralevator abscess (transrectal)
- Submucosal
- Deep posterior
indications after I&D anal absess for Abx
DM, cellulitis, immunosuppressed, prosthetic hardware
goodsalls rule anal fistula
ANTERIOR fistula connect with anus/rectum in straight line
POSTERIOR (or >3cm anterior) go toward midline internal opening in anus/rectum
mgmt anal fistula
If <25% sphincter and superficial: fistulotomy at time of drainage
If > 25% sphincter: drain abscess and place SETON
If simple fistulotomy cannot be done (I.e. > 50%) : LIFT (ligation of intersphincteric fistula tract) +/- anorectal advancement flap
rectovaginal fistula mgmt
HIGH: (form diverticulitis) needs abdominal approach, resection, close vaginal hole, temporaroy ileostomy
MID/LOW VAGINA: (obstetrical) transanal rectal mucosa advancment lap (leave vagina open)
Anal Abscess Treatment
- DRAIN:
Superficial perianal and ischiorectal: external I&D
Deeper intersphincteric/supralevator: internal transanal I&D - Abx if cellulitis/SIRS/immunosuppressed
- LOOK FOR FISTULAS. (1/3 will develop FIA)
Anal fistula types (5)
INTERsphincteric: MC.
TRANSsphincteric: across BOTH sphincter muscles (HIGH >1/3rd of complex or LOW <1/3rd of complex)
SUPRAsphincteric: between then UP AND OVER external
EXTRAsphincteric: runs OVER AND ABOVE the sphincter complex totally
Submucosal
Purpose of seton
Induce fibrosis
Convert HIGH fistula to LOW fistula for later procedures
Internal hemorrhoid grading.
I: internal only
II: Prolapse and spontaneously reduce
III: Manually reduce
IV: Not reducible
repair of imperforate anu
staged: 1. end colostomy with mucus fistula
- definitive: get contrast study through mucus fistula to see if there is a urinary fistula
approach to imperforate repair of fistula to bladdder
bladder fistula: abdominal approach
rectobulbar urethral fistula: perineal (posterior sagittal)
rectoprostatic urethral: abdominal
