TREATMENT OF ESOPHAGEAL INJURY

Published on 10/03/2015 by admin

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CHAPTER 42 TREATMENT OF ESOPHAGEAL INJURY

The treatment of esophageal perforations remains controversial, with uncertainty surrounding several aspects of surgical management: the preferred method of surgical repair, the management of injuries recognized late, and the role of cervical esophagostomy for diversion, among others. Much of this controversy stems from the uncommon nature of these injuries. The relative infrequency of esophageal injury may be attributed to the deep location of this collapsed structure that is surrounded by vital organs. Many penetrating wounds injure the heart or aorta and result in death at the scene. Blunt injuries to the esophagus are very unusual. Anatomic features, with the lack of serosa, contribute to the difficulty in treatment. Given the frequency of delay in diagnosis and the complexity of operative treatment, injuries of the esophagus remain among the most difficult injuries to manage without major morbidity or mortality. Even the busiest trauma centers often encounter fewer than five esophageal injuries per year.

INCIDENCE

The incidence of esophageal injuries is low with most resulting from penetrating trauma. Esophageal trauma received little notice until the completion of World War II, with only 18 esophageal injuries recorded in the military records reviewed from that war and the Korean and Vietnam Wars combined. Numerous reports in the literature document the incidence of esophageal trauma to be less than 1% with the most common cause being penetrating injuries sustained from stab and gunshot wounds. The cervical esophagus represents the most common site of injury followed by thoracic and abdominal esophageal injuries. While these wounds occur relatively infrequently, they continue to be associated with high mortality ranging from 20% to 30%. Virtually all patients who sustain an esophageal injury also incur associated injuries to other respiratory, gastrointestinal, and vascular injuries. As a result, surgeons must maintain a high index of suspicion so that untoward diagnostic delays may be avoided.

Penetrating injuries of the esophagus far outnumber blunt esophageal injuries. The predominant mechanism of esophageal trauma or injury is gunshot wounds (70%–80%) followed by stab wounds (15%–20%) and shotgun wounds (3%–5%). Esophageal injuries resulting from blunt trauma account for less than 1% of all esophageal injuries. These injuries are most often located in the cervical esophagus as the result of an anterior blow with the neck in a hyperextended position. An acute blow to a distended stomach may produce tears of the distal esophagus.

DIAGNOSIS

Diagnostic delays are often cited as significant factors in the high morbidity and mortality associated with injuries to the esophagus. Several factors contribute to this diagnostic delay including the uncommon occurrence of these injuries. Because associated injuries are common, delays may occur before the initiation of specific diagnostic tests to evaluate the esophagus. All the while, even a “simple” perforation elicits a massive inflammatory response with mediastinal tissue destruction that may further complicate the repair.

Esophageal injuries must be suspected in penetrating neck injuries that violate the platysma, in transmediastinal gunshot wounds, and with significant chest trauma with associated tracheobronchial injuries. The clinical findings most commonly associated with cervical esophageal injuries include neck pain and dysphagia. Tenderness to palpation and with passive motion, dyspnea, and/or hoarseness may be present. Hematemesis, hemoptysis, or bloody nasogastric tube aspirate in the absence of obvious oral or pharyngeal trauma should suggest the possibility of esophageal injury. Expanding cervical hematoma is certainly a cause for concern as are the subsequent development of fever, cough, and stridor. Palpable crepitus or air within the soft tissues or a wide prevertebral shadow on neck or cervical spine radiographs may be the initial suggestion of an esophageal injury. Computed tomography examination may demonstrate subcutaneous emphysema within the soft tissues or in the upper mediastinum.

The clinical findings associated with thoracic esophageal injuries may be nonspecific and initially absent. They may include abdominal tenderness and/or rigidity, cervical crepitation from tracking of mediastinal emphysema, and Hamman’s sign (mediastinal crunch on auscultation). The presence of mediastinal emphysema and pleural effusion in the face of penetrating thoracic trauma should elevate awareness for the possibility of a thoracic esophageal injury.

Subdiaphragmatic esophageal injuries often present with abdominal tenderness and/or rigidity. Patients frequently complain of abdominal pain and may progress to signs of frank peritonitis. Upright chest radiographs or computed tomography scans may demonstrate pneumoperitoneum.

While penetrating neck or thoracic wound with hemodynamic instability will often necessitate immediate exploration for associated injuries, the hemodynamically stable patient often presents a diagnostic challenge. In the past, all penetrating neck wounds that violated the platysma were routinely explored. However, many trauma centers now practice selective management of neck wounds. Selective management necessitates some type of study to exclude esophageal injury. We recommend a water-soluble contrast esophagogram in stable patients. If no injury is seen with this technique, addition of dilute barium adds a measure of safety in excluding an injury. Because contrast studies yield a false-negative rate of up to 25%, esophagoscopy may be added in patients regarded as high risk for injury. The specificity of a negative esophagogram accompanied by negative esophagoscopy approaches 100%. Even in hemodynamically stable patients with cervical hematomas who will undergo exploration, we advocate esophagoscopy, as the injury may be localized by the appreciation of blood or hematoma within the esophagus. It is often difficult to identify an esophageal injury during exploration due to extensive blood staining of the tissues. All studies should be obtained in an expeditious manner as prolonged time to diagnosis has been widely correlated to increased morbidity and mortality. Once an esophageal injury has been diagnosed, all oral intake is held, nasogastric tube decompression is performed, and intravenous fluid resuscitation and broad-spectrum antibiotics are initiated before prompt surgical intervention.

SURGICAL TREATMENT

While some penetrating cervical wounds may be managed nonoperatively, all confirmed esophageal injuries should be managed operatively in expedient fashion. The preferred surgical management of esophageal injuries is dictated by the location of the injury, stability of the patient, time to diagnosis, and associated injuries.

In our opinion, all esophageal injuries should be treated by general unifying principles regardless of location. These principles include (1) attempted closure of all defects by some method; (2) the use of onlay flaps, preferably muscular, as a buttress or for primary closure; and (3) tube drainage near the repair. Given the lack of a serosa, primary healing is not uniform. Therefore, the use of a buttress often enhances healing without fistula development. Local muscle flaps, in particular, are useful for either buttress or as a primary onlay repair.

Injuries to the cervical esophagus may be approached either by a collar incision or by an incision anterior to the sternocleidomastoid. An anterior unilateral incision should be made for unilateral cervical and single injuries, whereas a collar incision is indicated for midline, multiple, or bilateral cervical injuries. The esophagus is located deep to the trachea and placement of a nasogastric tube often facilitates localization by palpation. Throughout the dissection, great care must be taken to identify and avoid injury to the recurrent laryngeal nerves which are located in the tracheoesophageal groove. If further exposure is needed, the omohyoid muscle may be divided. After blunt dissection, the esophagus should be encircled by a Penrose drain in order to further facilitate the dissection.

Thoracic esophageal injuries are best approached through thoracotomy incisions based on the suspected level of the injury. Following initial studies, the decision for the incision should be determined by the presence of pleural effusion or defined leak identified on esophagogram. Injuries to the upper two-thirds of the thoracic esophagus are best approached through a right posterolateral thoracotomy though the fifth intercostal space. Injuries to the lower third of the thoracic esophagus are best approached through an incision in the left sixth intercostal space.

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