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Managing oral trauma and foreign bodies (Proceedings)

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Aug 01, 2010

Oral Cavity Soft Tissue Trauma

The soft tissues of the oral cavity are susceptible to traumatic injuries by bits or other oral tack, sharp external objects, blows to the head, injury during recovery from general anesthesia, and iatrogenic damage during intraoral procedures—for example, administration of oral medications, dental extraction, or transoral epiglottic entrapment release. The face and oral cavity soft tissues have a tremendous repairing capacity. Minor, superficial lacerations of the mucosa, lips, and tongue can heal effectively by second intention, usually within 2 weeks, without leaving a notable scar. Management may entail flushing of the oral cavity after meals with an antiseptic solution, warm salt water or clean water, and the use of nonsteroidal anti-inflammatory drugs. Larger wounds should be considered for surgical closure, to maintain tissue function, and for cosmesis. For these repairs, antimicrobial therapy may be needed in selected cases.

Tongue

Lacerations of the tongue are not uncommon and can be severe, with transverse lacerations more frequent than longitudinal ones. The free portion of the tongue is usually involved because of bit location and because this part has more exposure to the external environment. Clinical signs include oral hemorrhage, ptyalism, inappetence, anorexia, dysphagia, malodorous breath, pyrexia, and tongue protrusion from the mouth. Management of tongue lacerations is guided by the severity, duration, and location of the injury. Partial glossectomy, primary wound closure, or secondary wound healing are treatment options. Surgical procedures are most easily performed on the anesthetized patient; however, the tongue can be operated on in the standing horse with effective sedation and infiltration of local anesthetic. Traction on the tongue for exposure can be achieved by placing towel clamps in the tongue caudal to the laceration or by using a gauze snare at this site, which also serves as a tourniquet.

Partial glossectomy is reserved for cases in which the rostral tongue tissue is devitalized and minimal attachment is left between the severed section and the remaining body. Tissue color, temperature, and evidence of bleeding at an incision can be used to assess viability. After amputation, the remaining stump is meticulously débrided of nonviable tissue. Mucosal-to-mucosal closure of the stump is not imperative but is performed to aid hemostasis and hasten wound healing. Dorsal to ventral apposition is assisted by removing a wedge of intervening musculature and closing the created space with multiple rows of interrupted absorbable 2-0 or 0 sutures. The mucosal edges are subsequently closed with absorbable sutures of a similar size in an interrupted pattern, using tension relieving sutures as needed. Burying the knots in this layer will reduce the risk of suture tag irritation of the oral mucosa. Involuntary loss of saliva from the mouth may be observed after amputation of a large part of the free portion of the tongue.

Primary closure of severe tongue lacerations is encouraged whenever possible. The wound edges are débrided of necrotic and contaminated tissue and lavaged vigorously. A multilayer closure to eliminate dead space is recommended. To relieve tension on the closure, vertical mattress sutures are preplaced deep in the muscular body of the tongue with absorbable or nonabsorbable size 0 or 1 monofilament suture. Buried rows of simple interrupted 2-0 to 0 monofilament absorbable sutures are then used to appose the muscles, obliterating dead space. The vertical mattress sutures are tied, and the lingual mucosa is apposed with absorbable or nonabsorbable simple continuous 2-0 suture or interrupted vertical mattress sutures.

Second-intention wound healing for management of tongue lacerations is a viable option, particularly when economic constraints preclude surgical repair, and for chronic and less extensive lacerations. Oral lavage with a clean antiseptic solution two to three times a day and careful attention to the horse's ability to eat and drink are indicated. Lacerations that have healed by second intention but result in poor tongue functionality can be reconstructed using primary closure techniques after sharp débridement of scar tissue.

After lingual surgery, most horses eat normally, and temporary feeding via a nasogastric tube is rarely required. Gruels of pelleted feeds mixed with water, bran mashes, and wetted hay can be given before introducing drier feeds. Nonsteroidal anti-inflammatory drugs are administered, and antimicrobial therapy is used according to the level of presurgical tissue devitalization. Nonabsorbable sutures are removed in 2 weeks. Postoperative complications include excessive swelling of the tongue and suture dehiscence. The cosmetic appearance is usually highly acceptable.