Chapter 37 - Anal & Rectal++ Flashcards
What is the arterial supply to the anus?
Inferior rectal artery
What is the venous drainage above the dentate line? Below?
Above: Internal hemorrhoid plexus (prolapse)
Below: External hemorrhoid plexus (painful thrombosis)
Hemorrhoid plexus locations?
Left lateral, right anterior, right posterior.
Symptoms occur after venous congestions results in hypertrophy. Constipation and diarrhea over time will exacerbate this process.
Symptoms of external hemorrhoids?
Pain when they thrombose (excise if < 3 days; nonop mgmt can be done if > 4 days), swelling, itching
Symptoms of internal hemorrhoids?
Bleeding (needs colonoscopy) or prolapse (refer to surgery if doesn’t reduce spontaneously)
Grades of prolapse of internal hemorrhoids?
Primary: slides below dentate w/ strain
Secondary: prolapse that reduces spontaneously
Tertiary: Prolapse that has to be manually reduced
Quaternary: not able to reduce
Treatment for symptomatic hemorrhoids?
Every patient, every time: stool softeners, fiber, avoid straining, sitz baths, topical pain relievers.
Prolapse requiring manual reduction (grade III): surgical referral.
Thrombosed external hemorrhoids < 3 days: office excision.
Bleeding: outpatient colonoscopy.
Surgical indications for hemorrhoids?
Sx I or II dz refractory to conservative tx (6-8wks). Sx III (band vs -ectomy) or IV dz (-ectomy). Thrombosed external hemorrhoids if < 3 days (excision).
Banding for internal or external hemorrhoids?
Internal only. Best for grade I, II, or III.
IV requires hemorrhoidectomy.
Rectal prolapse begins how far from the anal verge?
6-7cm
What causes rectal prolapse? Risk factors?
Pudendal neuropathy and laxity of the anal sphincters; increased with females, straining, diarrhea, previous pregnancy, redundant sigmoid colons
Treatment for rectal prolapse?
High-fiber diet.
Transanal rectosigmoid resx (only if contraindx for OR)
LAR or rectopexy (low recurrence, for young/healthy).
Virus associated with condylomata acuminata?
Psx, Tx?
HPV (6 and 11), most common STD in colorectal office
Psx: raised cauliflower appearance on anus, itching; promiscuous patient
Tx: Can attempt pt applied imiquimod, podophyllotoxin vs clinician applied cryo, TCA. Can elect for surgical/laser/electrosurgical removal of macroscopic dz, no margins necessary (does not decrease recurrence rate), no LADx. Can combine if single tx fails.
Ppx: HPV vaccine
What causes anal fissure?
Split in the anoderm from straining
Where are anal fissures located?
90% in posterior midline. Odd/multiple locations or refractory dz can occur w/ Crohn’s.
Symptoms of anal fissure?
Pain and some bright red bleeding after defecation; chronic ones will see a sentinel pile.
Dx is clinical w/o DRE or scope (defer). Usually posterior midline, so lateral location should trigger evaluation for inflammatory diseases.
Medical treatment for anal fissure? Surgical?
Medical (1st line): sitz baths, bulk, lidocaine, softeners
Surgical (for chronic): lateral internal sphinctx for young and healthy; LIFT and/or advancement flap if pt is at high-risk for incontinence issues
Most serious complication of anal fissure surgery?
Fecal incontinence
What disease processes are contraindications to surgery for anal fissure?
If secondary to Crohn’s or UC
Drainage procedure for perianal, ischiorectal, and intersphincteric abscesses?
Perianal/ischiorectal - incision and drainage through skin if below the levator muscles.
Intersphincteric - EUA and internal drainage with division of the mucosa and internal sphincter muscle along length of fluctuance to allow free drainage
Drainage for supralevator abscesses?
Transrectally incision and drainage (no packing needed)
Treatment for pilonidal cyst?
Drainage and packing; follow up surgical resection of cyst
Treatment for fistula in ano?
3 main categories, each with different treatment.
The questions needing to be answered: Is a lot of the sphincter involved (are you gonna cause incontinence)? Can the patient tolerate a procedure?
1) If not much external sphincter (inter/transsphincteric) involvement and no incontinence: unroof fistula (fistulotomy) w/ curettage; do not need to excise the tract.
2) If complex, extensive sphincter involvement (>30%), high transsphincteric, suprasphincteric, extrasphincteric, horseshoe, recurrent: need sphincter-sparing procedure - do partial fistulotomy, draining seton placement, and future LIFT/advancement flap.
3) If complex and cannot tolerate surgery: do cutting seton.
What is Goodsall’s rule?
Anterior fistulas connect with rectum in straight line; posterior fistulas go toward midline with internal opening in rectum
Definition of simple rectovaginal fistula?
Secondary to infection or obstetrical trauma, low to midvagina, <2.5cm
Treatment for simple rectovaginal fistula?
Many heal spontaneously; transanally unroof and place rectal mucosa advancement flap
Definition of complex rectovaginal fistula?
Secondary to inflammatory bowel disease, XRT, neoplasm, or high in vagina, or >2.5cm
Treatment for complex rectovaginal fistula?
Abdominal or combined approach; resection and reanastomosis with placement of colostomy, need good tissue for anastamosis
Types of anal incontinence? Treatment?
Neurogenic: no good treatment
Abdominoperineal descent: damage to levator ani muscle and anus falls below levators, stretches the pudendal nerves; high fiber diet, limit to 1 bm/day, sphincteroplasty if related to trauma (childbirth)
Anorecatal problems associated with AIDS? Characteristics?
Kaposi’s sarcoma: nodule with ulceration
CMV: shallow ulcers, similar presentation as appendicitis
HSV: #1 rectal ulcer
B cell lymphoma: can look like abscess or ulcer
What type cancer found in the anal canal (above dentate line)?
Squamous cell CA: basaloid, mucoepidermoid, epidermoid, cloacogenic.
Adenocarcinoma.
Melanoma.
Treatment for squamous cell CA of anal canal?
If very faborable, can do local excision w/ strict follow up. Otherwise, will get chemoradiation: Nigro - 5FU, mitomycin, XRT.
Re-assess in 4-6 wks w/ anoscopy (no bx if better).
If this fails (persistent, recurrent): bx and APR.
Cure rate for anal squamous cell CA?
80%
Treatment for adenocarcinoma of the anal canal?
APR.
WLE if <1/3 circumference, limited to submucosa, well-differentiated, no vascular/lymphatic invasion, < 3 cm, proximal extend is ppalpable on DRE; needs 1cm margin; postop chemo/XRT.
Treat like rectal adenocarcinoma.
Treatment for melanoma of the anal canal?
APR; margin dictated by depth of lesion standard for melanoma
What accounts for most deaths due to anal canal melanoma?
Hematogenous spread to the liver and lung early
Most common symptom of melanoma of anal canal?
Rectal bleeding
What type of cancers are found in anal verge (below dentate line)?
Squamous cell CA, basal cell CA, Bowen’s disease (HSIL or AIN III), Paget’s disease
What is the treatment for squamous cell CA of the anal verge?
Same as for rest of anal canal.
Can do WLE for select T1 lesions - favorable, superficial, complete excision, less than 3 mm basement membrane involvement. Chemoradiation (FU, mitomycin) first line for the rest.
Treatment for basal cell CA of anal verge?
WLE usually sufficient; need 3mm margins; rare need for APR
What is Bowen’s disease?
Intraepidermal squamous cell CA
Associated conditions with Bowen’s disease?
1 or more primary internal malignancy or primary cancer of the skin with internal mets
Treatment for Bowen’s disease?
Local therapy, WLE with clear margins
What is Paget’s disease of anal verge?
Intraepidermal apocrine gland CA, slow growing, positive PAS stain
Treatment for Paget’s disease?
WLE with clear margins; groin dissection for positive nodes
Where do nodal mets from anal/rectal cancer go?
Superior and middle rectum: IMA nodes
Lower rectum: primarily IMA nodes, internal iliac nodes
Upper 2/3 of anal canal: internal iliac and pelvic nodes
Lower 1/3 of anal canal: inguinal nodes
What are the two clinical divisions of the anus?
The margin - area before the intersphincteric groove and the external hemorrhoids. Squamous epithelium.
The canal - includes external and internal hemorrhoids,
What are lesions of the anal margin with malignant potential?
HSIL, Paget disease
What infection is HSIL associated with?
HPV
Describe the presentation of Paget disease of anus.
Non-specific symptoms - itching, burning, bleeding.
PE - well demarcated eczematous plaques, ulcerative or papillary
How do you diagnose Paget disease?
Pathology, need biopsy.
What do you do with invasive adenocarcinoma of the anus without mets?
APR
What do you do with an invasive epidermoid cancer of the anus without mets?
This is SCC. Chemoradiation w/ Nigro protocol.
What do you do for non-invasive cancer of the anus?
local excision with clear margins (ie transanal excision)
a) < 30% circumference of bowel
b) < 3 cm in size
c) margin clear (> 3 mm)
d) mobile, non-fixed
e) within 8 cm of the anal verge
f) T1 only
g) well to moderately differentiated
h) no lymphovascular or perineurial invasion
i) no evidence of lymphadenopathy
What do you do with SCC of anal verge?
WLE with clear margins
What do you do with BCC of anus?
WLE with clear margins
What do you do with retrorectal tumors?
resect, even if asymptomatic
What is the initial workup of a patient with fecal incontinence once diarrhea has been ruled out?
Manometry
EAUS
Colonoscopy - rule out cancer or inflammation
Defacography (optional)
How is fecal incontinence managed?
Major defects (sphincter not intact) - sphincteroplasty.
Minor defets - diet and bowel habit, injectables.
Sacral nerve stimulation is next step.
Ostomy is salvage surgery.
What are the main hemorrhoidectomy complications?
Bleeding (suture ligate), urinary retention (30%, 2/2 pelvic floor muscle spasm), fecal incontinence
How do you differentiate hemorrhoids from rectal prolapse?
Rectal prolapse show circumferential tissue folds (radial in hemorrhoids).
Resting/squeeze pressure decreased in rectal prolapse (normal in hemorrhoids).
Anatomic/physiologic tests for obstruction caused by pelvic organ prolapse?
Dynamic defacography or dynamic MRI.
Where does the rectum begin? End?
Coalescence of the taenia coli of the sigmoid at the level of the third sacral vertebra. Ends as it passes through the pelvic floor (levators) to become the anal canal.
What landmark does the peritoneal reflection correspond to?
The second valve of Houston. 10 cm from the anal verge.
What is the blood supply to the rectum?
Superior rectal from IMA.
Middle and inferior rectal from the iliac.
Drainage follows this - the superior rectum drains through the portal. The middle and inferior rectum drain through the IVC.
What nodes can inferior rectal cancers go to?
inguinal
What are the boundaries of the anal margin?
from the intersphincteric groove (palpable groove between EAS and IAS) out 5 cm onto the perineum; covered by nonkeratinizing squamous epithelium that transitions to keratinizing at the outer border; somatic innervation
What are the boundaries of the anal canal?
top of levators (anal sphincter muscles) down to intersphincteric groove - corresponds to space held by internal anal sphincter; covered by transitional epithelium
After hemorrhoidectomy, a patient develops anal stenosis. How do you manage this?
Treatment can be as simple as improving stool consistency with laxatives. Serial dilation can be used as well. If stenosis does not respond to these options, Y-V anoplasty or other methods of anoplasty may be necessary.
A 54-year-old man presents to your clinic 48 hours after rubber band ligation of internal hemorrhoids. He is complaining of inability to void and worsening anal pain. Vital signs are temperature of 38.7ºC, heart rate of 88 beats/min, blood pressure 130/85 mmHg, and respiratory rate of 18 breaths/min. What happened? How do you manage?
Perianal sepsis, a rare but life-threatening complication after rubber band ligation (RBL) of hemorrhoids.
This condition requires rapid initiation of treatment:
- broad-spectrum antibiotics
- OR for EUA, drainage if abscess, debridement
What should be screened for in patients who are diagnosed with anal squamous cell cancer?
Females - cervical dysplasia
Everyone else - consider HIV
Pt s/p hemorrhoidectomy presents w/ bleeding within 24 hrs after a BM. Stool is bright red. What happened? What do you do?
Technical failure. Needs to be fixed urgently - go to OR for EUA and ligate the bleeding.
Pt is POD 6 from hemorrhoidectomy presents w/ bleeding after a BM. What happened? What do you do?
Likely 2/2 sloughing of the eschar. Should resolve on its own. If persistent, can come in for EUA.
Treatment of perianal skin cancer?
T1 well-differentiated that create a discrete lesion separate from anal canal - WLE, and if path shows high-risk features (poorly differentiated, perineural invasion), do postop RT.
All others, sphincter fct will be compromised, nodal involvement - chemoradiation, and if persistent or recurrent, do surgery.
What do you do with retrorectal tumors?
Resect all of them.
Often asymptomatic and found incidentally.
Transrectal US is sensitive. CT/MRI preop.
No need to bx preop.
Contraindication to fistulotomy?
Fecal incontinence.
Discuss solitary rectal ulcer syndrome.
Psx: rectal bleeding, copious discharge, anorectal pain, difficulty passing stool.
Dx: visualization of shallow ulcer w/ punched-out gray-white base w/ surrounding hyperemia, biopsy.
Tx: conservative tx
Discuss Paget disease of the anus.
Intraepithelial adenocarcinoma
Psx: woman in 70s-80s w/ severe intractable itching and erythematous and eczematous rash.
Dx: biopsy; then f/u to find occult cancer - CT, colonoscopy (50% w/ cancer).
Tx: WLE w/ perianal biopsies.
Pt w/ Crohn presents w/ anal fissure. How do you manage?
Medical management first.
EUA to eval for other pathology if this fails.
