37 - Anorectal Flashcards
Arterial supply to the anus
inferior rectal artery
Venous drainage of the anus above and below the dentate line
Above the dentate line - Internal hemorrhoid plexus
Below the dentate line - External hemorrhoid plexus
Hemorrhoid distal to dentate line, causes pain when thrombosed
External
External hemorrhoids covered by what cell type
Squamous epithelium (sensate)
Hemorrhoid that slides below dentate line with strain
Primary/Grade 1 internal hemorrhoid
Hemorrhoid that prolapses and reduces spontaeously
Secondary/Grade 2 internal hemorrhoid
Hemorrhoid that prolapses and has to manually be reduced
Tertiary/Grade 3 internal hemorrhoid
Hemorrhoid that prolapses and not able to be reduced
Quaternary/Grade 4 internal hemorrhoid
Tx for thrombosed external hemorrhoid
<72 hrs - excision
>72 hrs - lance
Can tx _ hemorrhoids with banding
Grade 1/2 INTERNAL hemorrhoids
On internal hemorrhoid resection, need to resect down to _
Internal anal sphincter
Surgical tx of rectal prolapse if pt is elderly/frail
Perianal rectosigmoid resection (Altermeier) transanally
Surgical tx of rectal prolapse if pt is good condition
LAR with pexy
Cauliflower mass, associated with HPV
Condylomata Acuminata
Chronic anal fissures are also associated with a finding of _
sentinel pile (anal skin tag)
90% anal fissures location
Posterior midline
Percent of anal fissure heal with medical tx
90%
Surgical tx for anal fissure
Lateral subcutaneous internal sphincterotomy
Lateral or recurrent anal fissures concerning for _
Inflammatory bowel disease (Crohn’s/UC)
Types of anorectal abscess that can be drained through skin (3)
Perianal
Intersphincteric
Ischiorectal
Types of anorectal abscess below the levator ani (3)
Perianal
Intersphincteric
Ischiorectal
Types of anorectal abscess that can form horseshoe abscess
Ischiorectal
Intersphincteric
Types of anorectal abscess requiring transrectal drainage
Supralevator
Goodsall’s rule
Anterior fistulas connect in straight line
Posterior fistulas track towards a midline internal opening of anus
When can you perform fistulotomy
Fistula in lower 1/3 of external anal sphincter
MCC of simple rectovaginal fistula
Obstetrical trauma
Simple rectovaginal fistula location
low to mid-vagina
Complex rectovaginal fistula location
high in vagina
MCC of complex rectovaginal fistula
Diverticulitis
Tx of simple rectovaginal fistula
Rectal mucosa advancement flap
Tx of complex rectovaginal fistula
Abd or perineal/abd approach with resection and anastomosis
Chronic damage to levator ani muscle and pudendal nerves; anus falls below levators
Abdominoperineal descent anal incontinence
Tx of obstetrical trauma anal incontinence
Anterior anal sphincteroplasty
Most common cancer in AIDS pts, nodule with ulceration
Kaposi’s sarcoma
Shallow ulcers, similar presentation as appendicitis in immunocompromised pts
CMV (cytolomegalovirus)
1 rectal ulcer in immunocompromised pts
HSV (herpes simplex virus)
In immunocompromised pts, cancer that can look like an abscess or ulcer
B-cell lymphoma
Common associations with anal cancer (3)
HPV
HIV
XRT (radiation)
Anal canal cancer lesions are located _
Above dentate line
Anal margin cancer lesions are located _
Below dentate line
Tx for anal canal squamous cell CA
Nigro protocol (5-FU, mitomycin C, chemo-rads)
What is the nigro protocol
5-FU
Mitocycin C
Chemo-rads
When can you tx anal canal adenocarcinoma with WLE
WLE with 2-3mm margin if <4cm, <50% circumference, limited to submucosa, well differentiate and no neurovasc invasion
Tx for anal canal adenocarcinoma
Surgery (APR vs WLE) + chemo-rads
3 most common sites for melanoma
1-skin
2-eyes
3-anal canal
Most common sx for anal melanoma
Rectal bleeding
Tx for anal melanoma
APR
Mets of squamous cell CA of anal margin go to _
inguinal nodes
Tx of anal margin squamous cell CA <5cm
WLE with 0.5cm margin
Tx of anal margin squamous cell CA >5cm, involve sphincter or node involvement
Chemo-rads (5-FU and cisplatin)
Cancer with central ulcer, raised edges, below dentate line
Basal cell CA of the anal margin
Tx of basal cell CA of anal margin
WLE with 3mm margin
APR if sphincter involved
Nodal metastases of superior and middle rectum
IMA nodes (inf mesenteric artery)
Nodal metastases of lower rectum
IMA and internal iliac nodes
Nodal metastases of anal canal
internal iliac nodes
Nodal metastases of anal margin
inguinal nodes