External laryngotracheal trauma: a case series and an algorithmic management strategy

In preparation of this report, the authors complied with all guidelines of the Committee on Publication Ethics.

Figure 2 shows our unit’s protocol to manage patients with ELT presenting to the emergency room (ER) either in a non-intubated or an intubated state.

The first evaluation follows an “A, B, C, D, E” assessment in the ER, where there is a close collaboration between the difficult airway response team [8, 9] that includes emergency physicians, anesthesiologists, ENT and other services (radiology, neurosurgery, orthopedics, trauma surgery etc.).

Depending on the situation, intubation was done using either a flexible bronchoscope used as a guide to pass the endotracheal tube through the traumatized larynx or by using a rigid ventilating bronchoscope (Storz, Germany). Precise diagnosis of laryngeal dynamic functions and local mucosal-cartilage lesions is difficult once an endotracheal tube has been passed. Therefore, when it was judged possible, a flexible bronchoscopy followed by an examination with a Rod lens telescope was made (Fig. 3).

In case of major anatomical modifications in the neck secondary to subcutaneous emphysema or expanding hematoma, we preferred intubation with the patient breathing spontaneously using flexible endoscopic guidance. In a similar situation sometimes, an awake intubation could be an attractive option but this requires collaboration of the patient. Topical anesthesia in the upper airway in both techniques is crucial. In the context of cervical spine trauma—sedation, maintaining spontaneous breathing, neck immobilization and flexible bronchoscopy-guided intubation is ideal.

In a patient with a stable airway, having no airway symptoms and a normal nasofibroscopy, the probability of an inconspicuous injury is low. In such cases, standard intubation, followed by a detailed aero-digestive examination was done.

B: Breathing: A chest X-ray was performed for patients with low cervical injuries, looking for signs of pneumo-/hemo-thorax.

C: Circulation: This point concerns ELT with a penetrating wound wherein the carotid artery, internal jugular vein, thyroid gland and vessels, other neck and mediastinal vessels may be injured. In case of hemodynamic instability due to massive bleeding, the patient was transferred directly to the operating theatre having a head-neck and vascular surgeon backup.

In a totally stable patient, a contrast CT scan and Doppler angiography were performed to know about the degree of vascular injury, and then decide the treatment strategy either by interventional radiology (via embolisation) or by open surgery.

D: Disability: Emergency physicians assessed the patient’s level of consciousness using the AVPU scale (Alert: the patient is vigilant, although not necessarily orientated., Verbal: the patient makes some kind of response when spoken to, Pain: the patient responds to a painful stimulus, Unresponsive: the patient does not show evidence of any eye, voice or motor responses to pain) [10].

E: Exposure: For a patient with ELT injury having a stable airway and was hemodynamically stable, the treating team closely examined the neck, thorax and abdomen for other injuries.

A significant number of patients (90%) were referred from other institutions. Prior to discharge from our hospital, all patients had a check endoscopy and were evaluated by our speech and swallow therapists.

Respiration was subjectively evaluated as normal, with forced exertion, with moderate exertion, at rest and objectively by endoscopy.

The pattern of patient referral and the fact that they were seen by different doctors after returning to their institutions made it difficult to have an optimal objective voice assessment. Phonation was judged as normal voice, mild dysphonia (described as hoarse voice with some difficulties of being heard or understood in a loud environment), moderate dysphonia (described as weak to breathy voice, easy fatigability) and severe handicap with difficulty to communicate.

Various authors tried to define neck zones to help determine the nature and degree of tissue injury [7]. Zone I is below the omohyoid muscle corresponds to the supra- and infra-clavicular areas and may involve the innominate vessels, common carotid artery, subclavian vessels, vertebral artery, brachial plexus, trachea, oesophagus, lung apex, and thoracic duct. Zone II is between the hyoid bone and the cricoid cartilage and includes the thyroid gland, carotid and vertebral arteries, internal jugular veins, trachea, and oesophagus. Finally, zone III is above the hyoid bone and up to the base of the skull. Trauma in this zone will implicate injury to the proximal carotid artery, the vertebral arteries, and the pharynx.

All our patients had injuries in zone II, predominantly involving the larynx and trachea and none injuring the major neck vessels and nerves, the pharynx and the oesophagus.

Recently, most authors advocate a “no zone management” [11, 12] and recommend searching for signs that correspond to the underlying injury. “Major or Hard signs” include pulsatile hematoma, expanding hematoma, massive subcutaneous oedema, air bubbling through the wound, severe hematemesis or hemoptysis, or focal neurological deficit. “Minor or Soft signs” include stable hematoma, hoarseness, dysphagia, mild subcutaneous emphysema, minor hematemesis or hemoptysis, neck pain, cough, change of voice, and aspiration (that may appear later when the patients begin to eat).

In the case of complex ELT, all the usual anatomical landmarks in the neck could be lost or hidden by a hematoma, subcutaneous oedema/emphysema, or a laryngotracheal separation. In such cases, it is best to start with a flexible bronchoscopy in the patient breathing spontaneously to gather maximum information about the airway proximal and distal to the trauma site, secure the airway by intubation or by rigid bronchoscopy and then perform the tracheostomy. In our opinion, a surgical cricothyroidotomy must be avoided as it adds to the airway trauma, and it anyway gets converted to a tracheostomy during surgical exploration. Tracheotomy under local anesthesia is risky in cases of lost anatomical landmarks, and may evoke a sudden deterioration of the airway.

The new tracheostomy is a source of infection to the laryngeal injury and must be placed further distally, depending on the extent and site of the LT injury. A prior high tracheostomy should be placed more distally during surgical correction of the injury.

The decision about the appropriate timing and the indication of a CT scan (high-resolution of the head, neck and thorax with contrast media injection) is based on the patient’s overall stability. For a stable or a stabilized patient, the imaging will help the surgery or decision-making in a conservative approach. Most authors [4, 7, 12] recommend that patients with ‘hard signs’ must have an immediate CT scan (after securing the airway) before going to the operating room to detect the source of bleeding, hematoma, subcutaneous emphysema, pneumo ± hemothorax and the potential laryngeal lesions (fractures or dislocations of the cricoid, hyoid, thyroid cartilage, arytenoid luxation). However, the patient must be rushed to the operation theatre without a scan in case of torrential bleeding with a backup of vascular surgeons. The CT scan in a patient with ‘soft signs’ will help to determine whether a surgical exploration is required.

The goal of surgical management is to re-establish airway patency and preserve or recreate the functional anatomy of the upper aero-digestive tract.

The main objectives of performing an upper aero-digestive endoscopy are: (1) evaluate the dynamic functions of the upper airway; (2) systematically document the airway lesions (pharynx, larynx, trachea and bronchi); (3) secure the airway; (4) perform a pharyngo-esophagoscopy to rule out pharyngeal tears, oesophageal trauma and insert a nasogastric tube.

In our experience, injuries in the pharynx, pyriform sinus and upper oesophagus are best diagnosed by carefully using a rigid telescope and without further traumatising the injured mucosa. Flexible endoscopy causes collapse of the pharyngeal mucosa and minor injuries may be missed. Additionally, insufflation of the upper digestive tract during flexible pharyngo-eso-gastroscopy can cause subcutaneous emphysema, pneumomediastinum and pneumothorax.

Isolated fracture of the hyoid bone is usually treated conservatively with diet changes and analgesics, as it is painful during swallowing. In the presence of displaced or comminuted fractures, it is critical to realign and fix the osseous fragments using mini-plates (titanium or biodegradable polymers). In addition, the petiole of the epiglottis must be fixed in the correct position to prevent supraglottic stenosis in the future.

One of our patients needed an additional endolaryngeal stenting using the LT mold (Lausanne University Hospital, CHUV, Switzerland, Fig. 3, 3b) to prevent collapse of the supraglottic airway and required a temporary distal tracheostomy.

External blunt trauma compresses the thyroid, cricoid and extra-thoracic tracheal cartilages against the spine (Figs. 1, 3a, b). Damage to these cartilages depends on the degree of calcification, meaning the injuries will be worse in elderly patients. A blunt injury typically results in a vertical, linear, median, or paramedian fracture. Special care must be given in these cases during the dynamic endoscopy because the incidence of concomitant uni- or bilateral recurrent laryngeal nerve palsy(s) is high. The rebound impact on the thyroid cartilage disrupts the anterior glottic commissure and the epiglottic petiole insertion, and if left untreated or is sub-optimally treated can cause supraglottic and glottic stenosis (Figs. 2a, b, c, 3).

Exposed cartilages, multiple or displaced cartilaginous fractures require open surgical exploration. Fragments must be reduced and fixed with titanium osteosynthesis miniplate(s) (DePuy Synthes, Zuchwil, Switzerland) (Fig. 4), stainless-steel wire, or non-absorbable monofilament sutures (3, 4.0 Prolene, Ethicon). Patients with crushed cricoid ring will require a tracheostomy. Vertical cricoid fractures can be fixed with mini plates and temporary LT mold stabilization. Select non-displaced fractures may be managed conservatively and could have a good prognosis.

It is preferentially treated endoscopically, except by an open surgery in the presence of other injuries. Isolated arytenoid dislocation has good functional results if they are reduced within three weeks [4], followed by speech therapy. Sometimes, cricoarytenoid ankylosis (CAA) may subsequently develop, and the patient will require a long-term follow-up. In the case of a unilateral joint fixation, contralateral cord mobility may compensate, and by itself may not cause long-term respiratory distress. However, sometimes to improve phonation and/or swallowing, overcompensation by redundant supra-arytenoid mucosa on the side of the fixity in uni- or bilateral CAA can occur causing respiratory symptoms and this may need limited laser trimming of the floppy tissue. In extreme cases of bilateral fixation, posterior arytenoidectomy or a laryngofissure with posterior glottic expansion using a rib cartilage graft will be necessary to treat glottic obstruction.

Severe damage will require a tracheostomy if it has not been already done in an emergency. Mucosal lacerations at the anterior commissure will require a laryngeal Keel placement (Laryngeal Anterior Commissure Stent LACS, Boston Medical Products) (Fig. 3a). Massive mucosal lesions will require an LT mold placement to avoid a future dense glottic synechiae formation and vocal cords fusion. Both, the LACS and the LT Mold can be endoscopically fixed in the glottis under suspension laryngoscopy using a Lichtenberger’s needle carrier [14] and 3.0 Prolene suture.

A laryngotracheal disruption is one of the most severe laryngeal injuries. It is nearly always associated with uni- or bilateral recurrent laryngeal nerve injury(s). In addition, concomitant cricoid fractures and pharyngoesophageal tears are often present.

Meticulous debridement, correct approximation of the laryngeal and tracheal stumps, and tension-free anastomosis are the keys to a successful laryngotracheal reconstruction. Associated cricoid fractures are reduced and fixed with resorbable (Vicryl or polydiaxanone) sutures or osteosynthesis titanium mini plates. Internal stabilization with an LT mold may be necessary in the presence of extensive damage to the laryngotracheal framework and fractures of the posterior cricoid plate.

Multilevel LT injuries may require a Montgomery T tube or the LT mold placed over a T tube.

Missed phayrngo-esophageal injuries might be left untreated, and may cause aero-digestive fistula and mediastinitis with catastrophic consequences.

We stent an ELT in the following situations:

In patients with laryngotracheal disruption or cricoid fracture, recurrent nerve(s) damage is frequent [4]. Systematic nerve exploration is not recommended as it may be difficult in swollen tissues and could lead to further damage to a potentially intact nerve. If the nerve transection is obvious, a direct end-to-end anastomosis can be attempted after freshening the nerve edges or recurrent to ansa cervicalis anastomosis may be performed [4].

The main drawback of this communication is its retrospective design applied to a small number of patients with rare injuries.