Sunday, September 23, 2007

Ear Lacerations, Abrasions, and Avulsions

As mentioned before, the location of the ear in a prominent, unprotected position on the side of the head makes it susceptible to injuries. Many of us remember Mike Tyson biting the ear of Evander Holyfield in their fight in Las Vegas on June 28, 1997. (photo credit) It is a form of an open injury to the ear. These injuries include lacerations (with and without cartilage exposure) and avulsions. Sharp trauma to the ear causes lacerations to the pinna’s cartilaginous framework. This requires minimal debridement and suturing of the perichondrium and skin in alignment with the remaining natural landmarks. Because the blood supply in this area is excellent, primary closure is usually successful, and even tenuous flaps will generally survive.

Lacerations of the auricle (both photos credit) require careful realignment to maintain the contour of the auricle. I like to use a mixture of Lidocaine with epinephrine and Marcaine without epinephrine for a local block. The Marcaine will provide some longer lasting pain control. With the local in place, the wound can be more thoroughly inspected and cleansed. Lacerations involving only the skin may be repaired using basic suture techniques.

Lacerations involving all layers of the auricle require more extensive repair. Each of the layers--cartilage, perichondrium and skin--has to carefully examined for necrosis. The necrotic tissue is sharply debrided, being careful to preserve as much "good" tissue as possible. The cartilage is reapproximated and the perichondrium is sutured over the cartilage with a small-gauge 5-0 or 6-0 absorbable suture (vicryl or dexon). If possible, sutures through cartilage should be avoided. The skin is repaired as above. After repair, a pressure dressing is applied for 48 hours to minimize edema and prevent formation of a hematoma (and to prevent the late complication--cauliflower ear).

Abrasions are a frictional contact injury which result in partial loss of the covering epidermis (skin) of the ear. The affected area may show punctate bleeding, formation of hemorrhagic blebs and even exposure of the underlying dermis or perichondrium. As with lacerations, these wounds should be infiltrated with local so that a thorough inspection and cleansing can be done. All foreign bodies must be removed to prevent infection or "tattooing". A topical antibiotic ointment or cream is applied to prevent surface contamination and secondary infection. A protective dressing may be applied for the first 24 hours. The patient should be instructed to return promptly if pain, fever or swelling develops. Such symptoms usually signal the development of perichondritis, which requires immediate aggressive management. Superficial abrasions generally heal within one to two weeks.

The majority of Avulsion injuries to the ear are from bites. They may be partial (some part still attached) or complete (piece of tissue completely free). When partial, then the ear should be repaired as a laceration. If complete, then reattachment should be done as soon as possible. For best results, complete avulsion injuries should be treated with microvascular reattachment. If this option is not available (or feasible) then the pocket principle may be used. It was first described by Mladick, et al in 1971.

Pocket principle (below three photos from the 5th reference article)-
-Avulsed tissue should be debrided and the surface dermabraded

-The tissue is then anatomically reattached
-The ear is then buried in post-auricular pocket



-After 2-4 weeks, the pocket is opened and the ear removed
-Ear is then allowed to re-epithelialization or is skin grafted.

The pros for the Pocket Principle are 1) provides immediate blood supply, 2) preserves skin/cartilage relationship. The cons are that 1) the aesthetic results are variable, and may be poor if left buried too long and 2) there may be granulation tissue formation.

Lacerations of the pinna can progress to severe chondritis or perichondritis and so along with suturing must be treated antibiotics. Human bites contaminate the wound with the oral flora of the mouth. "Unfortunately, no well-controlled studies have investigated using antibiotics to prevent infection in human bite wounds. Uncontrolled studies have involved cephalosporins and generally do not indicate a benefit of prophylactic antibiotics. Once a human bite is infected, beta-lactamase–producing staphylococci must be addressed. Eikenella corrodens may not be covered by first-generation cephalosporins. Additionally, Eikenella species are resistant to clindamycin, penicillinase-resistant semisynthetic penicillins, and metronidazole. A broad-spectrum antibiotic, rather than combination therapy, is the usual choice for infected bite wounds. A recent in vitro study of 50 infected human bites by Talan et al indicated that amoxicillin-clavulanic acid and moxifloxacin demonstrated excellent activity against common isolates"--Dr McNamara

References

  • Ear, Reconstruction and Salvage by Steven P Davison, DDS, MD --eMedicine Article
  • Bite Wounds of the Head and Neck; Brian H. Weeks, M.D.; June 24, 1999; Department of Otolaryngology- Head and Neck Surgery V.A. Hospital (Power Point )
  • Cuts and Wounds of the External Ear--University of Virginia Health System
  • Initial management of auricular trauma; American Family Physician, May 15, 1996 by Dennis Lee, Neil Sperling
  • THE POCKET PRINCIPLE: A New Technique for the Reattachment of a Severed Ear Part; Plastic & Reconstructive Surgery, 48(3):219-223, September 1971; Mladick, Richard MD, Horton, Charles MD, Adamson, Jerome MD, Cohen, Bernard MD
  • Bites, Human by Robert M McNamara, MD--eMedicine Article

1 comment:

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