Gen Surg: Anal disease

Question 1

Differential Diagnosis for Anorectal Complaints (12)

Answer 1

3 H’s: HPV (warts), Hemorrhoids, Hidradenitis Suppurativa (painful bumps around anal sebaceous glands)

4 P’s: prolapse, pruritis, pilonidal disease, perianal abscess
Other/gen: Trauma, malignancy, IBD, fissure, fecal incontinence

Question 2

Define the following anatomical sites of the anus and specify areas of pain sensation: dentate line, proximal transition zone, distal to transition zone.

Answer 2

Dentate Line: Transition zone between the proximal columnar epithelium (rectal mucosa) and distal squamous epithelium (skin).

Proximal to transition zone: columnar epithelium, no nerve endings (no pain). Drains to mesenteric lymph nodes.

Distal to transition zone: squamous epithelium, contains nerve endings (pain). Drain to superficial inguinal LN.

Question 3

Questions on focused history for perianal complaints:

Answer 3

Symptoms:
Pain, bleeding, prolapse, soilage/seepage, prolapse, straining, urgency or incomplete evacuation (alarm signs for cancer), itching, change in BM (constipation/diarrhea/stool calibre changes)

Signs: tenderness, fluctuance of area, erythema, mass, discharge, anal tone/squeeze, prolapse.

Question 4

Components of the physical exam of the perineum:

Answer 4

DRE: Inspect anal outlet, palpate cirumferentially. Pt should be in prone or LLD position. Valsalva maneuver to exaggerate prolapse.

Anoscopy: visualize the first 5 cm of the anus.

Question 5

Etiology of hemorrhoids (4)

Answer 5

Elevated intraabdominal pressure, pregnancy, constipation/chronic straining, weight lifting.

Question 6

Define hemorrhoid

Answer 6

Pathological pressure on arteriovenous plexus, causing swelling of cushion and protrusion into the anal canal. May be internal (proximal to the dentate line) or external (distal to the dentate line)

Question 7

Contrast internal vs external hemorrhoids

Answer 7

External: distal to dentate, painful on thrombosis, constant protrusion/lump that may leave a skin tag after healing, bleeds only if ruptured.

Internal: proximal to dentate, causes PAINLESS bleeding, has grading system to describe.

Question 8

Grading system for internal hemorrhoids

Answer 8

1: non-prolapsing
2: prolapses but self-reduces
3: requires manual reducation
4: cannot be manually reduced

Question 9

Symptoms of hemorrhoids

Answer 9

Bleeding, protrusion, pruritis (difficult perianal hygiene due to skin tags), seepage and soilage

Question 10

Treatment for hemorrhoids

Answer 10

Conservative: High fiber diet (25-30 g/day), high fluid intake, stool lubricant/softeners, decrease toilet time, sitz baths or topical lidocaine with steroid for pain relief.

Office based procedures: rubber band ligation (grades 1-2), injection sclerotherapy, infrared coagulation, sonographic ligator.

Surgical procedures: excisional hemorrhoidectomy, stapled anopexy, sphincterotomy, anal stretch.

Question 11

Perianal abscesses: etiology, symptoms, potential locations, mgmt

Answer 11

Etiology:
Cryptoglandular: anal crypt gland at dentate line becomes obstructed and infected. Gland penetrates anal sphincter so suppuration follows path of least resistance resulting in abscess collection in anatomic space that gland terminates.
Other causes: carcinoma, Crohn’s, trauma.

Symptoms: pain, swelling, drainage, bleeding, constipation, urinary difficulties.

Locations:
Perianal (superficial, close to anal verge, easiest to treat).
Ischioanal (peri-rectal, ischiorectal fossa lateral to anal opening and passing external sphincter).
Intersphincteric (btwn internal and external sphincter, difficult to diagnose b/c completely in anal canal. Causes severe anal pain, need to examine under anesthesia).
Supralevator: above levator ani in pelvis. pelvic and rectal pain with tenesmus, more common in immunocompromised)

Mgmt: IVF and abx, I+D, wound packing.

Question 12

Describe the different classifications of perianal fistula

Answer 12

Form from chronic abscess and classified based on relation to anal sphincter complex.

Submucosal fistula: from dentate line through submucosa, not involving sphincter.

Intersphincteric fistula: cross internal sphincter and exit from intersphincteric plane (doesn’t involve external sphincter).

Transphincteric fistula: crosses internal and external sphincter. Higher = more incontinence.

Suprasphincteric: crosses above external sphincter and exits on perianal skin.

Extraphincteric: does not involve sphincter complex and originates above dentate line.

Mgmt: depends on amount of sphincter involved. Typically obliterate the internal opening. The more external sphincter involved, the more incontinence.

Question 13

Role of imaging for perianal abscess/fistulae

Answer 13

CT for ID of perianal abscess.
MRI for fistula.
US is ineffective.

Question 14

Anal fissures: Etiology, symptoms, mgmt

Answer 14

Fissure: tear in skin usually posterior to midline and distal to dentate line.
Etiology: Trauma (e.g. large, hard stool, diarrhea), hypertonic/hyperspastic internal sphincter, diminished blood flow/ischemia.

Symptoms: Pain with bowel movements, lasts 2 hrs afterward. Get spasms, bleeding, seepage, soilage, difficult evacuation.

Mgmt:
Conservative: sitz baths, stool softener, pain relief. Topical CCB (sphincter dilation, decreases spasms), botox injections.
Surgical: lateral internal sphincterotomy (reduces spasms by cutting hypertrophic internal sphincter), anoplasty, fissurectomy, anal stretch.