Unlike in human medicine, post-traumatic facial reconstruction has received little attention in small-animal surgery.1 Reports of treating facial trauma cases are limited,2,3 and no retrospective or prospective studies could be found in the literature. Most publications focus on oncologic surgery of the face.4-6 This case report details a successful reimplantation, without microvascular anastomosis, after traumatic subtotal amputation of the maxilla and discusses potential guidelines for decision making in similar cases.
A 4-year-old, 21.3-lb (9.7-kg), dolichocephalic, mixed-breed, intact male dog was evaluated at the emergency service of the veterinary teaching hospital of the Universidade Estadual de Londrina, about 20 minutes after sustaining a severe facial injury. The owner saw the accident, which occurred while the dog was asleep under farm machinery. A plow coulter fell, splitting the dog's maxilla. The owner immediately wrapped a clean towel around the dog's mandible and maxilla and brought the dog to the hospital.
Examination and treatment options
On arrival, the dog was tachycardic (176 beats/min), had a capillary refill time of more than two seconds, and had apparently lost a considerable amount of blood. An 18-ga catheter was inserted into the cephalic vein, and lactated Ringer's solution was rapidly infused (90 ml/kg/hr for the first 30 minutes) while fresh blood was collected from a donor for transfusion. Cefazolin sodium (30 mg/kg) was given intravenously before the lesion was inspected.
Initial inspection revealed a complete oblique cut that severed the skin and bones of the maxilla at the level of the nasomaxillary suture junction and reached the oral mucosa at the level of the hard palate. The laceration extended from the nasomaxillary suture dorsally to the level of the left maxillary canine tooth and the interdental space of the second and third right maxillary premolars (Figure 1). The rostral maxilla was precariously attached to the rest of the face by a thin strip of tissue (about 4 mm thick) from the left lip and a full thickness, 2.5-cm-wide portion of the upper lip on the right side (Figures 1 & 2). The right lip flap was later found to include the right infraorbital artery, which was patent. The dog was breathing through the lesion. Once the blood transfusion (about 200 ml) was initiated and the patient's hypovolemia was corrected, further physical examination revealed a 1-cm full-thickness skin laceration on the craniodistal aspect of the right antebrachium. Because this patient needed immediate surgical intervention, no preoperative diagnostic tests, including radiography, were performed.
Figure 1: A lateral view of a traumatic subtotal amputation of the maxilla in a 4-year-old dog that sustained the severe facial injury from a farm equipment accident. The laceration extends from the left maxillary canine tooth (arrows) to the interdental space between the second and third maxillary premolars on the right side (arrowhead) (A—oroesophageal tube; B—endotracheal tube).
The options for this patient were to perform primary reconstruction or a bilateral rostral maxillectomy followed by delayed facial reconstruction. The owner was informed about the potential complications of a primary reconstruction, which could result in failure, requiring a late maxillectomy, as well as the likely unacceptable cosmetic results from a radical maxillectomy. The limited availability of soft tissue for primary closure of the maxillectomy defect was a big concern, as was the possibility of a disfiguring open wound that would need to be treated until delayed reconstruction could be done.
Figure 2: A dorsal view of the facial injury in the same dog shown in Figure 1. Note the aboral extension of the laceration to the right side of the face (arrows).
Morphine (0.4 mg/kg intramuscularly) was administered for perioperative pain management. General anesthesia was induced with intravenous propofol (5 mg/kg), and the dog was intubated. Anesthesia was maintained with sevoflurane (1.5%) and 100% oxygen. After the wound was protected with sterile petroleum jelly ointment and gauze, the dog's face was clipped, and the wound was lavaged with 1.5 L 0.9% sterile saline solution and wrapped in sterile laparotomy sponges.