Welcome. Once again, we have a lovely topic
to discuss, perianal and perirectal abscess.
And as you're already thinking to
yourself, that's not going to be fun.
Yes, if you're a patient
with this, it's not fun.
So, these are collections of pus, local areas
of necrosis with an intense neutrophilic infiltrate
caused by anal gland obstruction
and secondary infection.
The epidemiology of these overall is that
it can pretty much happen throughout one's lifetime.
Men seem to be more frequently affected
than women by a two to one margin.
30% of these patients have
had prior anal rectal abscess.
So, if you've had it once, it's likely to come back.
Immunosuppression is also a risk factor for these.
The pathophysiology is basically obstruction of the anal glands.
There are a number of anal glands.
We'll talk about these in turn. I don't think you need
to memorize them, just be aware of the specific locations
and how that may impact your ability
to diagnose and/or treat.
But the anal glands drain into crypts
along the dentate/pectinate line.
So, they are dumping their contents.
These are going to be mucus
to help lubricate stool at the very last stages
of elimination from the colon.
Those anal glands normally drain if they become
obstructed or if there's retrograde infection,
then, we will develop perianal, perirectal abscess.
The gland obstruction can be due to a number
of things listed here. So, there's non-specific.
Meaning, we don't know.
That's the vast majority of cases.
Inflammatory bowel disease and especially Crohn's
disease involving the rectum will classically do this.
Trauma, and trauma not in the sense of an automobile accident
but having something inserted forcefully into the rectum.
Malignancy or extension of an adjacent
infection, all of these are reasons
for having the glandular components
to be obstructed and then, infected.
Any of the glands that are associated with the rectum
or the anus can be involved and have various locations.
Clearly, whatever microorganism is living
in that part of the anus will be able to infect.
So, it can be an E. Coli or Klebsiella,
any normal GI flora.
So, we're looking at a number
of the normal locations for glands.
And let's talk about when they become infected.
So, the most common perianal infection abscess
is going to be the - is going to be the perianal abscess
and it extends and continues
into the fat of the buttocks.
These are going to be the most superficial,
most easily incised and drained from an external approach
but fortunately, also, the most common
so that we can see them and treat them.
There are perianal abscesses
that involve the ischiorectal location.
So, lateral and posterior to the anus
and inferior to the levator ani.
There are those that involve the inter-sphincter regions
between the various muscles involved in the sphincter.
And then, finally, the space above the levator ani,
giving you a super levator abscess.
Some of these are going to be much
more easy to palpate and see.
Others are going to be clearly deeper
such as this one. Clinical presentation.
So, pain is going to be the primary manifestation,
tends to be rather severe, can be dull and achy.
It's a constant pain and it's clearly exacerbated by the movement
of fecal material along the bowel and with straining at stool.
An external or digital rectal exam will
demonstrate swelling, tenderness, and fluctuance
and that is going to be probably your best
indicator that there is a perirectal abscess.
Because of the inflammation, because of the pain,
patients may variably describe either constipation,
kind of an obstruction to movement of stool
or if there's a lot of inflammation
and that's causing in fact evacuation of the
anal canal, then, you may get diarrhea.
Depending on whether there is actual drainage
from the obstruction, you may have purulence in the stool.
You may have blood in the stool.
There's occasionally, because of secondary
inflammation associated urinary retention.
And clearly with significant infections,
you may have systemic signs.
So, fever, elevated white count, and things like that.
Making your diagnosis. It is primarily a clinical diagnosis.
You turn your patient over,
you do a gentle external examination,
and for the vast majority of your perianal
abscesses, that's going to be it.
For those that are deeper, you know, so, those
involving for example, the levator, you may need CT
or MRI or ultrasound to look
for fluctuant accumulations.
Management, so, management is -
let's treat the infection. And surgery.
So, in most cases, once you have an abscess,
antibiotics alone are insufficient to treat
and that's an abscess anywhere on the body.
You need to incise and drain,
an I and D, to remove the vast majority of the necrotic
debris and the bacteria and allow healing to proceed.
So, antibiotics and surgery are going to be your mainstays.
And with that, a painful topic comes to a close.