A 58-year-old woman with non-small cell lung cancer accepted right-sided video-thoracoscopic wedge resection surgery. A left-sided 35 French/Ch Mallinckrodt^TM double lumen endobronchialtube (DLT) with stylet was inserted smoothly, and confirmed by auscultation and fiberoptic bronchoscopy. Mild hypotension (BP: 85/60 mmHg) was found while turning her left decubitus without changes on ventilation pressure. After artificial pneumothorax, pneumomediastinum with concealed numerous widespread air bubbles was noted immediately by thoracoscopic view directed to apical chest wall (Figure 1). The blood pressure returned to normal once the mediastinum was opened to release the air. A shallow “V-shaped” laceration (arrow heads) was noted in the carina (C) by repeated bronchoscopic examination (Figure 2). The DLT was extubated smoothly after the video-assisted thoracic surgery (VATS) right middle lobe wedge resection. The following X-ray two hours later showed significant pneumomediastinum and “left” pneumothorax (Figure 3). The patient was admitted to intensive care unit for one night without any discomfort, and was discharged five days after the surgery.

Double lumen endobronchial tube is a common instrument in thoracic surgeries. The estimated incidence of tracheobronchial rupture was reported approximately 0.3%, and was higher in women [1],[2]. Previous reports demonstrated that most common ruptured sites are distal trachea and posterior membranous wall of main bronchi [3].

Small, negligible laceration by a smooth endobronchial catheter intubation with routine fiberoptic bronchoscope could lead unpreventable injury. Without signs of tension pneumothorax, severe, concealed pneumomediastinum could be fatal by undetected cardiac tamponade effect. In this case, unexplained hypotension is the only clinical symptom. In clinical practice, accidental tracheobronchial injuries following endobronchial catheter insertion remain unpreventable. An unexplained intraoperative hypotension may be a surrogate for a tracheobronchial injury and it may be the midway with a concealed pneumomediastinum heading to disaster tension pneumothorax. Transthoracic or transesophageal echography (TTE or TEE), if available, may provide a quick diagnosis and a guide of releasing for unstable hemodynamics. A glance on mediastinum by video in VATS operations also provides early diagnosis and management. A postoperative X-ray is stronglyrecommended, because a small laceration in carina may lead to contralateral pneumothorax as well.

Accidental tracheobronchial injuries following endobronchial catheter insertion is unpreventable.We presented this case with unexplained hypotension and images to demonstrate a concealed pneumomediastinum as a midway to disaster tension pneumothorax.