To the Editor, We read with great interest the article by Gelpke and coworkers, who report their experience with recurrent laryngeal nerve (RLN) monitoring during esophagectomy and mediastinal lymph node dissection using a laryngeal surface electromyography (EMG) electrode attached to a doublelumen endobronchial tube in 12 consecutive patients [1]. Postoperative impairment and damage of the RLN has an incidence up to 31 % in left lung resection for malignancy [2] and between 34 and 80 % for surgery for esophageal cancer [3, 4]. We agree and support the thesis that intraoperative monitoring of the RLN may facilitate identification of the nerve during esophagectomy and lung surgery and may reduce the incidence of RLN injury. For successful monitoring of the RLN accurate positioning of the surface electrodes between the vocal cords is crucial. However, because of the small dimension of electrode recording part (1.5 9 1.5 cm), maintaining positioning could be challenging with a double-lumen endotracheal tube after the patient is brought into a lateral position. Therefore, we like to add a possible refinement to the method applied in another case report of a patient undergoing abdomino-right-thoracic-esophagectomy [5]. To cover a larger recording electrode area [5], we attach two surface electrodes, one after the other, on the double-lumen endobronchial tube starting 2 cm above the tracheal cuff. After patient positioning into the left lateral position, the RLN is stimulated transcutaneously. The surface electrode that obtains the better recording results is used for intraoperative monitoring. Generally, a double-lumen endobronchial tube is prone to displacement during patient positioning and surgery. Repositioning an electrode-bearing endobronchial tube interferes with single-lung ventilation. Gelpke and coworkers measured the distance between the true vocal cord and the main bronchus on the preoperative computed tomography (CT) scan to establish the ideal position of the surface electrode on the endobronchial tube; however, in one nerve at risk, electromyographic (EMG) recording was impossible. A possible explanation—most likely a displaced electrode—could be anatomic: e.g., the distance between vocal cord and main bronchus may differ between supine position (CT scan) and left lateral position (singlelung ventilation). However, after considering the risk of electrode displacement and trauma from in situ detachment of the surface electrode, we now use a ready-made EMGendotracheal tube system (Xomed-EMG-tube; Medtronic Xomed, Jacksonville, FL) in combination with a newly available bronchus blocker (EZ-blocker, AnesthetIQ, Delft, the Netherlands) to enable RLN monitoring during single lung ventilation [6]. After intubation with the Xomed tube, the Y-shaped EZ-blocker is placed under bronchoscopic visualization through the tube on the carina. If desired, the left or right main bronchus could be blocked with the two cuffs alternately. The advantages of this method are as follows: (1) it facilitates endotracheal intubation, especially during rapid sequence induction, (2) it allows the possibility of repositioning the endotracheal tube in case of lacking EMG signal without interfering with single lung ventilation, and J. Schmidt A. Irouschek S. Heinrich T. Birkholz (&) Department of Anesthesiology, University of ErlangenNuremberg, Krankenhausstr. 12, 91054 Erlangen, Germany e-mail: t.birkholz@gmx.de