Iatrogenic Tracheal Injury during Cardiac Surgery

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A 59-year-old man was taken up for coronary artery bypass graft surgery. After an uneventful anesthetic induction and intubation with a cuffed endotracheal tube (ETT) of internal diameter 8.5 mm, the surgeon used electrocautery in the suprasternal space for the division of the interclavicular ligament before sternotomy. At this point, a low tidal-volume alarm from the anesthesia machine was noted, and end-tidal carbon dioxide tracing suddenly became flat. The breathing circuit tubing and its connectors were found intact. The surgeon noticed an air leak sound and air bubbles coming out from the trachea. An injury to the trachea and the cuff of the ETT was suspected. Meanwhile, the lungs were manually ventilated using low tidal volume, high respiratory rate, and high fresh gas flow to compensate for the air leak. The surgeon noted a 4–5 mm longitudinal laceration in the anterior tracheal wall, which was immediately repaired using an interrupted 4–0 absorbable suture. After tracheal repair, the ETT was replaced with the help of a tube-exchanger, and the removed ETT was examined. It showed burn-like deposits and a tear at the cuff [Figure 1 and Video 1]. A fiberoptic bronchoscopy was performed, which ruled out any tracheal stenosis or bleeding at the repair site. Normal ventilation was resumed and the contemplated surgical procedure was performed. A careful monitoring for signs of air leak (loss of tidal volume) was performed. Post-operative course of the patient was uneventful and the patient was extubated 6 h after surgery.

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Figure 1: Removed endotracheal tube showing tear at the cuff (arrow) caused by electrocautery-induced thermal injury.

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Iatrogenic tracheal injuries can be life-threatening, requiring prompt recognition and management. Most iatrogenic injuries occur as a complication of orotracheal intubation (more common with double-lumen ETTs), tracheal stenting, or during procedures such as tracheostomy or esophagectomy. Tracheal injury occurring during division of the interclavicular ligament is extremely rare, with only a few cases reported in the literature.^[1-3] Two authors have reported full-thickness thermal tracheal injury due to electrocautery before sternotomy, as happened in this case,^[1,2] and one patient had tracheal injury during the excision of the interclavicular ligament by scissors.^[3] The tracheal tear can also occur while using a sternal saw from the xiphoid to the manubrium during sternotomy, especially in patients with a short sternotracheal distance.^[4] Tracheal rings lie just behind the interclavicular ligament, and they can be inadvertently cut by electrocautery or engagement of the saw during sternotomy if the surgeon is inexperienced or not careful. Tracheal injury can potentially lead to an airway fire and can cause alteration of respiratory mechanics in the form of airway collapse, air leak, or tracheal stenosis.^[5] Airway collapse can lead to difficulty in breathing or ventilation, while air leak can potentially cause pneumothorax or subcutaneous emphysema. Long-term complications of tracheal injury include scar tissue formation, tracheal stenosis, tracheoesophageal fistula, and recurrent laryngeal nerve injury, causing hoarseness of voice. Tracheal repair can lead to the formation of granulation tissue and subsequent stenosis, causing airway obstruction. Anastomotic dehiscence can also adversely affect the respiratory mechanics. The management goals for tracheal injury include protection of the airway, maintenance of oxygenation and ventilation, and prompt repair of the tracheal injury.

In conclusion, a sudden ventilation failure occurring before or after sternotomy should alert both the surgeon and the anesthesiologist to this potential complication, and the surgeon should be careful while using electrocautery in the suprasternal space.