Small Animal Sx - The Ear 1

drraythe's version from 2015-11-24 19:57


Question Answer
what is the cleanliness level of the ear sx?Rather than perform repeated lavage of the external ear canal, it is probably better to accept that aural surgery is a contaminated procedure. Hence, perioperative antibiotics are indicated.
should you give abx with ear procedures?yes, you should give perioperative abx bc ear sx is a CONTAMINATED procedure
what is the landmark for removal of ear canal/ total ear canal resection?anthelix
anatomy of the ear (pic)(we care about the 4 colored ones)
Where is the anthelix? it is 1- the little shelf
where is the tragohelicine incisure? It is 2- the little dip between the anthelix (shelf) and the tragus (triangle)
where is the tragus? it is 3- the triangle thingie
where is the intertragic incisure? it's 4, the other dip on the lateral side of the tragus (not to be confused with the tragohelicaine incisure which is between the anhelix and the tragus)
why is it so important to know your landmarks well?need to be near ear canal bc lots of nerves and vasculature you can damage around the ear. Such as the cranial nerves-- ESP THE FACIAL NERVE
where do bugs like to hide in the ear?osseus bullae
why are recurreances of ear infections so common?the bugs just go down into osseus bullae to hide during treatment and then come back out after
2 portions of ear canal?vertical and horizontal
3 sx conditions of the external ear are..(1) otitis externa (2) stricture of the ear canal (usu from chronic otitis externa) (3) neoplasia (usu seruminous glands)
B-day says how many times of recurring otitis externa before sx should be considered?3time
If there is chronic otitis externa, what dx procedures should you do?culture and senstivity of exudate, maybe stuff for pathology too
in order to do a thorough otoscopy, the pt anesthetized
technique for otoscopyhave to pull the ear down (to straighten out the vertical ear canal) and then slide otoscope horizontally towards the ear canal
tx of ACUTE cases of otitis externaMEDICALLY tx--> clean ear before topical therapy, systemic abx, if indicated, for 3wk. tx for mites or fungal infxn must continue for 3-4 weeks. (*he said he doesnt like to do this more than 3 times, then consider sx)
tx of CHRONIC cases of otitis exteranSX TX


Question Answer
3 surgical procedures for otitis externa?(1) lateral ear canal resection (LaCroix or Zepp's procedure) (2) vertical ear canal resection (3) total ear canal ablation, combined with lateral bulla osteotomy (TECA-LBO)
in essence what are you doing in a lateral ear canal resection (LaCroix or Zepp's procedure)? Why is this effective?just removing lateral aspect the the vertical ear canal-- changes environment and pH
what is going on in an TECA-LBO procedure? downsides? (total ear canal ablation, combined with lateral bulla osteotomy) remove horizontal and vertical ear canal AND scrape out the bulla. If done bilaterally patients might be deaf.
what procedure is this? what are possible complications to this procedure? this is the LaCroix-Zepp procedure (aka lateral ear canal resection) and the problem is that if the section removed was not big enough, or there is too much granulation tissue, it can become strictured
If you are performing a vertical ear canal resection on a cropped-ear dog, what will you need to warn owners about?they might get floppy ears again, depending on how much cartilage is removed.
how to do vertical ear canal resection? (the incisions)know anatomy! anhelix (shelf), the two incisures, and the tragus. Incisures give diameter of incision were gonna make. Make circular incision, including the tragus, can go below or take the anthelix, or above anthelix (depends on severity etc). Palpate ear canal (should be firm and elastic, maybe mineralized a bit if super chronic) and feel for "elbow" where the vert canal becomes the horizontal canal. Extend incision to the elbow.
how to do vertical ear canal resection? (after incisions, up to removal of vert canal)you've bluntly dissected and freed up this cone that is the ear canal, and go up to the annular ligament which is the boundary between the vert and horiz ear canal. Dissect AGAINST the cartilage to avoid damaging local nerves orally or aborally to the canal (which is why it's good to have upper part of cone dissects from the very beginning so you can move it back and forth, esp to reach medial aspect.) So then at level of annular lig tansect ear canal, remove, and send to pathology.
how to do vertical ear canal resection? (after vert portion of canal is removed-- closure)once vert canal removed, you're left with horizontal canal. Split this in half with two cuts, and then suture MUCOSA TO SKIN (not reverse)--> place sutures at 3,6,and 9o'clock and then 12o'clock to maintain opening while you are closing. To check if opening is good enough, should be able to insert hemostat up to the joint comfortably. Then continue up to sew together skin and SQ of where the vert. portion was. Infiltate area with local anesthetic to help reduce head-shaking post-op
cutaneous/subq structures you need to be aware of in the area of your vertical ear canal resection?cutaneous trunci mm, Preauricular muscle, parotid gland (separate bluntly from ear canal)
when is TECA-LBO indicated?more severe and advanced cases which include mineralization and thickening of the osseus bulla
what is the surgical technique for a total ear canal ablation with lateral bulla osteotomy? (in 2 steps)(1) begin with vertical ear canal resection (2) continue by removing horizontal canal- use rongeurs to remove medial bony portion
Explain how to do the TECA-LBOstart same as vertical ear canal ablasion (see other cards) but instead of stopping at the annular ligament, you keep going up to the external ear meatus (bony lateral prominance that connects the osseus bulla to the ear canal) *when you are here, be super careful bc facial nerve is right behind it* (ID the facial nerve, use umbilical tape if you wanna keep it apart- pull super gently). using MAYO (not metz) trim cartilage of canal from the external ear meatus at level of osseus bone. If mineralized, might have to use a ronguer to eat out the bone and open up the lateral aspect of the osseous bulla. Once opened up you need to flush it gently, and then scrape it with a curette to remove all the epithelium (if any left behind might lea to a recurrance)...the way to scrape is, when you insert the curette, the pt is in L recumb and insert on side of mandible and scrape towards yourself-- not away, bc otherwise you can damage the ossicles/innervation to the area. Then place a drain (exiting through 2* incision), then suture SQ and skin back together.
IMAGE for how to rongeur/curette the osseus bulla in the TECA-LBO
why we so worried about the facial nerve with the TECA-LBO?it is RIGHT THERE.
should you bandage the TECA-LBO?no, they cause more problems (head shaking) than good
when do you remove the sutures for a TECA-LBO?14d

Aural hematoma (external ear dzs)

Question Answer
etiology of aural hematoma?not well defined- usually shaking of the head, esp if they have droopy ears, may facilitate the breakage of cart. and separation of the skin.
what are some things you can do with an aural hematoma?(1) incise, evacuate hematoma, suture (2) aspirate hematoma, steroid injection into space (?) place pressure bandage (?) (3) cannula catheter/drainage (*this slide he kinda skipped over)
what happens if you leave a aural hemotoma to heal on it's own?it will be resorbed, but the pinna will be deformed
what is a good kind of cannula to use for drainage?Larson teat cannula bc self retaining, and has a cap, and several holes.
how do you insert a cannula?grab ear and go to distal tip of it, make an incision in INSIDE portion of ear, pause to allow for drainage, look for clots, wash, flush (he said some ppl like to use steroids in flush but he doesnt think it makes a difference) Then insert the Teat cannula. Pass a stitch through the phalange/colarette/border of it to hold it in place
how long will the teat cannula stay there?7-21d
explain dermal punch techniquemake holes with dermal punch tool (don't go all the way through the ear tho) take skin from MEDIAL aspect of pinna, then place suture that should involve the cartilage to stick the skin and cart together again.
If you decide to use of the technique of incise, evac hematoma, and suture closed, what are the diff ways to go about this? (incision? after you make the incision?)(1) straight- must remove 5mm on each side of incision to avoid closing prematurely and not allowing proper drainage. (2) curved ("italian s") (3) eliptical, where make eliptical piece of skin and leave a big opening. ------ After make incision, for all three, you place stitiches- horizontal mattresses, staggered, through and through the pinna. Go with a straight needle (or if you can't find that, a BIG BIG curved needle) so that it is easier to pass. Preplace them and then tie them on the external side. CONSIDE the edema/inflammation- so tie tight enough but not too tight ((or sutures will cut through the skin)
what can you do to add more structure and support to your aural hematoma repair if you are using an incisional method?can add a commercial foam or old radiograph film. can be ear sandwhich or just one side, either way it is strong and applies pressure.
what is a trick you can do to minimize the mess of the draining and healing ear hematoma?cut an absorptive cage liner and tape it to exterior of e collar next to affected ear