Figure: 4. The Labrador retriever shown in Figures 2 & 3 about six months after recovery. (Photograph courtesy of Deenie Galipeau.)
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Follow-up evaluations were obtained in all remaining cases for a mean of two years after surgery (range = five months to nine
years). All dogs had been normal at home, and no abnormalities were found on physical examination. The Labrador retriever
with the extensive pyothorax had no clinical signs of pulmonary compromise such as exercise intolerance or tachypnea (Figures 3 & 4).
DISCUSSION
Our results indicate that most thoracic impalement injuries that were managed surgically occurred in young, active large-breed
dogs. These dogs were commonly injured by running into sticks protruding from the ground or fallen tree branches and were
presented for evaluation of entry wounds in the ventral cervical area or thoracic inlet. Impalement in this location is particularly
dangerous because the foreign body may traverse the thorax and damage intrathoracic structures on either side. Fallen wood
may be rotten and prone to splintering, leaving debris within the tissues that may lead to chronic pyothorax or draining tracts.
Case management recommendations
Direct your initial diagnostic evaluation of animals with thoracic impalement injuries at determining whether the foreign
body entered the thoracic cavity, since this may influence case management including decisions about the location and timing
of surgery. Direct the initial therapeutic efforts at stabilizing the patient. The index of suspicion of intrathoracic injury
should be high in animals with severe tachypnea or dyspnea.
Radiography and endoscopy
Obtain thoracic radiographs as soon as the patient is stabilized. Although wood and plastic foreign bodies are radiolucent,
based on our results, most dogs with intrathoracic impalement injuries have radiographic evidence of damage to thoracic structures.
Pleural effusion was noted in all the dogs in this case series, and subcutaneous emphysema, pneumothorax, and pneumomediastinum
were also common. Because none of the dogs were found at surgery to have major lacerations of the pulmonary parenchyma, trachea,
or esophagus, subcutaneous and intrathoracic air most likely entered the thorax through the entry wounds. However, endoscopy
or tracheoscopy may be warranted in certain cases, such as in dogs with massive pneumomediastinum, marked ptyalism, or evidence
of dysphagia.
Our study included only dogs that underwent thoracic exploratory surgery, and these dogs were identified by a review of surgical
logs. The utility of thoracic radiography for predicting thoracic penetration may be overestimated by our results since it
is possible that some dogs with thoracic penetration during this period did not have surgery and that a proportion of these
dogs may have had normal thoracic radiographic findings.
Wound exploration and thoracotomy
Recommendations for managing dogs with impalement injuries
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Wound exploration and exploratory thoracotomy are indicated in all dogs with clinical or radiographic evidence of thoracic
penetration.7-9 In animals without apparent thoracic penetration, the wounds should also be explored, and the surgeon should be prepared
to enter the thorax if intraoperative exploratory findings dictate it. These findings include a palpable instability of the
thoracic wall, evidence of air bubbling from the thorax, or evidence of a tract extending into the thorax. Additionally, in
wounds near the diaphragm, the abdominal cavity may require surgical exploration as well.9 Consider emergency surgery in patients with severe respiratory difficulty that cannot be relieved by oxygen administration
or percutaneous placement of a thoracostomy tube and in patients with evidence of ongoing intrathoracic hemorrhage. No dog
in this study had evidence of severe intrathoracic hemorrhage documented in its medical record. It seems likely that most
dogs with a laceration of a great vessel would die before presentation to a veterinary hospital.
After anesthesia induction, remove any remaining exposed foreign material. If the object cannot easily be removed with gentle
traction, cut away the exposed portion and remove the remainder intraoperatively. Using excessive traction to dislodge the
object risks enlarging the entry wound or damaging intrathoracic structures. After removing the exposed portion of the foreign
object, prepare a wide area surrounding the entry wound for surgery.
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