ACDF is one of the most commonly performed surgical procedures for managing degenerative cervical diseases or trauma [1, 2]. Approximately more than 90% of patients reported being satisfied with the clinical and radiological results following ACDF. Therefore, it has been widely accepted as the gold standard treatment of cervical radiculopathy, myelopathy, and trauma [2]. However, according to multiple previous studies, dysphagia (1.7 to 9.5%), postoperative retropharyngeal hematoma (1.3–5.6%), respiratory insufficiency (1.1%), and esophageal perforation (0.3 to 0.9%) contribute to the morbidity rates for ACDF, which vary from 13.2–19.3% [5]. Among the several complications associated with ACDF, airway compromise is considered one of the serious life-threatening conditions and usually requires emergent treatment, including airway establishment and hematoma evacuation surgery [6, 7]. The risk factors for a second hematoma evacuation surgery include three or more level surgeries, obesity, anemia, use of anticoagulation agents, and male gender [5]. In our case, there were no related risk factors except male gender.
Lied et al. found that postoperative retropharyngeal hematoma commonly occurred during the on immediate phase (0 to 6 hours) with airway compromise [8]. O’Neill et al. reported that 65% of postoperative retropharyngeal hematomas occur within 24 hours, and 35% within 6 days [9]. Therefore, late onset of this complication is rare, as shown in our unique case. Regarding postoperative airway compromise following ACDF, predictable etiologies by time were reported as follows: angioedema (6 to 12 hours), retropharyngeal hematoma (12 to 24 hours), pharyngolaryngeal edema (24 to 72 hours), and retropharyngeal abscess (72 to 96 hours) [4]. Generally, emergent evacuation should be recommended for retropharyngeal hematoma at the time of diagnosis because it can cause life-threatening events due to acute airway compromise. In our case, retropharyngeal hematoma and edematous changes mechanically compressed the trachea, resulting in anatomical deviation and distortion. Furthermore, an attempt to secure the airway by forceful endotracheal intubation caused severe trachea mucosal damage, and the unforeseen consequences included tracheal stenosis which required bronchoscopic dilatation. Therefore, timely and appropriate urgent intervention at the diagnosis of retropharyngeal hematoma is very important to prevent further unforeseen complications.
Tracheal stricture and stenosis are sequalae of complications from endotracheal or translaryngeal intubation and cause serious problems, such as dyspnea on exertion [10]. The incidence of tracheal stricture and stenosis varies according to the duration of endotracheal intubation and severity of trachea mucosal damage [11]. In general, the severity of tracheal stricture and stenosis depends on the severity of trauma at the time of endotracheal intubation, high balloon pressure, and excessive movement during the intubation period [12]. Only 2% of cases with endotracheal intubation less than 6 days reported tracheal stricture and stenosis. In our case, although the duration of endotracheal intubation was just 2 days, tracheal stricture and stenosis occurred secondary to tracheal mucosal damage. We hypothesize that forceful endotracheal intubation caused excessive tracheal mucosal damage, resulting in tracheal stricture and stenosis, in a patient with a mechanically compressed and deviated trachea caused by a large retropharyngeal hematoma [13]. The most common site of tracheal mucosal damage is the endotracheal tube cuff site because pressure from the cuff on the tracheal wall can cause loss of local blood flow [12, 13]. Bronchoscopy is the mainstay of diagnosis for tracheal mucosal damage and stricture. In addition, bronchoscopic dilatation and/or stent insertion can be useful [12]. In cases of delayed onset retropharyngeal hematoma, our case suggests that emergent hematoma evacuation is a better treatment choice than delayed surgery with forceful endotracheal intubation to avoid the complications of tracheal stricture and stenosis.
Currently, the guidelines for the management of acute onset postoperative retropharyngeal hematoma are not well established [14]. Several cases of retropharyngeal hematoma have been successfully resolved by providing oxygen with the patient in the sitting position [15]. However, only patients with stable vital signs and no definite severe respiratory compromise symptoms, such as stridor, swelling, and cyanosis, can be considered for conservative management [2]. Many studies recommend emergent hematoma evacuation surgery for rapid improvement of symptom and prevention of potential life-threatening events. However, no guidelines for the management of delayed onset retropharyngeal hematoma have been established. Therefore, our case is thought to be helpful in determining the appropriate treatment for delayed onset retropharyngeal hematoma.
In conclusion, our case of delayed onset retropharyngeal hematoma showed that forceful endotracheal intubation can cause tracheal ischemic mucosal damage, which can result in tracheal stricture requiring bronchoscopic dilatation. In cases of delayed onset retropharyngeal hematoma, early surgery to remove the hematoma might yield better results and avoid unforeseen complications of tracheal stenosis and stricture.