Anus and Rectum (Makary Ch 23) Flashcards
Where is the dentate line?
In the anal canal about 2cm from the anal verge
What is the anal verge?
the junction the anoderm and the perianal skin
What is the dentate line?
separates proximal columnar epithelium from the distal squamous epithelium
what drains at the dentate line?
anal glands (at the bottom of the columns of Morgagni) drain their secretions into the anal canal
What is the anoderm? (How are they innervated?)
the hairless squamous epithelium between the dentate line and the hair bearing perianal skin (anal margin)
Somatic innervation
What comprises the external anal sphincter?
What nerve innervates it?
Voluntary or involuntary?
Skeletal Muscle
Striated skeletal muscle has three parts: Deep, superficial and subcutaneous
All layers innervated by somatic sensory fibers from the pudendal nerve
VOLUNTARY
What comprises the internal anal sphincter?
What nerve innervates it?
Voluntary or involuntary?
Continuation of circular smooth muscle layer of the rectum
Visceral sympathetic and parasympathetic fibers from pre sacral nerves
INVOLUNTARY - constitutively contracted
What is the definition of a hemorrhoid?
Tufts of vascular and connective tissue that are normally present in the anal canal
Internal vs. External hemorrhoids - which one causes pain?
External hemorrhoids
What is a grade 1 internal hemorrhoid?
bleeding without prolapse
What is a grade 2 internal hemorrhoid?
prolapse with spontaneous reduction +/- bleeding
What is a grade 3 internal hemorrhoid?
Prolapse requiring manual reduction +/- bleeding
What is a grade 4 internal hemorrhoid?
prolapse that is not reducible
Treatments for Grade 1 internal hemorrhoids (3)
Dietary fiber supplements, avoidance of straining, rubber band ligation
Treatments for grade two hemorrhoids
Same as grade 1, but rubber band ligation required more frequently
What type of hemorrhoids are treated with a hemorrhoidectomy?
Grades 3 and 4
What are the two ways to perform a hemorrhoidectoy?
Staple vs excisiononal
What is the benefit and the risk of stapled hemorrhoidectomy?
Benefit - decreased post op pain
risk - rare, severe persistent anal pain
What is a thrombosed external hemorrhoid?
A blood clot in an external hemorrhoid causing acute pain
When do you operate on a thrombosed hemorrhoid?
If diagnosed within 1-2 days. If delay in diagnosis (2-4 days), pain caused by excision is greater than pain from resolving hemorrhoid
What is the treatment for delayed presentation of thrombosed hemorrhoid? What is the timeline of “delayed presentation”?
Considered delayed if 2-4 days after onset of pain.
Sits baths, pain medications
Where do 90% of anal fissures occur?
posterior midline
What disease do you worry about with lateral or recurrent fissures?
IBD. Do not treat these surgically
Conservative treatments - anal fissure?
Warm soaks (sitz baths), stook bulking agents, nifedipine ointment and topic anesthetics
Two ointments used to treat anal fissures?
Nifedipine - a calcium channel blocker
Nitroglycerine
Goal is to relax sphincter muscle, increase blood flow to improve healing
Option for treating chronic anal fissures?
Botox
When does one consider a lateral internal sphincterotomy?
anal fissures refractory to conservative treatment
What is the most common reason for persistent pain following a left internal sphincterotomy?
The sphincterotomy was inadequate
intersphincteric fistula in ano (parks classification)
tracks between internal and external sphincter
most common kind
transphincteric FIA (Parks classification)
tracks through through both internal and external sphincters
Suprasphincteric Fistula in ano (parks classification)
Tracks up over the EAS
Extra-sphincteric Fistula in ano (parks classification)
The internal opening is in the rectum, not at the dentate line
Goodsall rule: Anterior or anterolateral external opening usually tracks …
directly radially into the anal canal (straight path)
Goodsall rule: Posterior or posterior-lateral external openings typically track»_space;>
curvilinearly into the anal canal
