Double-Lumen Tube Intubation Using the McGrath MAC Videolaryngoscope—Corkscrew Maneuver

To the Editor, The McGrath MAC videolaryngoscope is widely acknowledged for its efficacy in difficult tracheal intubation,[1] offering a clear glottic view without needing to align the oral, pharyngeal, and tracheal axes. This feature is especially valuable during cardiac anesthesia, where stabilizing blood pressure during intubation is critical. Since the blades of the McGrath MAC videolaryngoscope do not have a spatula for tube guidance function, the tube tip must be bent along the blade. The left-side double-lumen tube (DLT) is curved where it is inserted into the left main bronchus. By bending this section along the blade, the entire tube forms a double curve,[2] which makes it easier to maneuver for tracheal intubation. Challenges arise when the tube tip’s curve is insufficiently sharp, often causing the tip to head toward the arytenoid rather than the glottis. One potential solution is the cuff inflation technique.[3] In this method, as the tip of the tube proceeds toward the arytenoid, it is directed toward the glottis by inflation of the cuff. When the tip of the tube faces the glottis, the cuff is deflated, which allows the tracheal tube to pass through the glottis. However, this procedure is complicated. Conversely, if the tube’s bend is strong, it may collide with the anterior tracheal wall, complicating passage through the glottis. Given that DLTs are less flexible than standard tracheal tubes, these complexities are heightened when using the McGrath MAC videolaryngoscope. The sequential rotation technique[4] has been employed to mitigate these difficulties. This technique involves partially removing the stylet and rotating the tube clockwise 180° once the tip crosses the glottis, followed by another 90° rotation to insert the tube into the left main bronchus. While effective, this 270° rotation adds complexity to the procedure. In response, we devised a simplified approach for left-sided DLT intubation, with the following steps: After the tube tip crosses the glottis, the stylet is fully removed and the tube rotated 180° counterclockwise, preventing collision with the anterior tracheal wall and directing the tip toward the tracheal membranous portion. The tube is gently advanced until the white cuff passes the glottis. A 90° clockwise rotation follows, with continued gentle insertion. A bronchoscope is used to verify tube positioning via the white and blue ports. If the DLT tip mistakenly enters the middle trunk of the right bronchus, resistance may occur. In such cases, the tube can be withdrawn, and a bronchoscope can guide the tip to the left main bronchus through the blue port. This method offers several advantages: it simplifies anesthesiologist movements by limiting tube rotation to 180°, reducing complexity compared with the 270° rotation in the sequential method. Furthermore, the 90° clockwise rotation aids in guiding the bronchial tips into the left main bronchus, making the process safer and more efficient. We believe that this simplified technique enhances the safety and ease of DLT intubation with the McGrath MAC videolaryngoscope, providing a reliable alternative to the sequential method [Figure 1].Figure 1: (a) The tip of the double-lumen tube (DLT) crosses the glottis but collides with the anterior wall of the trachea and does not proceed any further. (b) The DLT is advanced by rotating the tube 180° counterclockwise and pointing the tip toward the tracheal membranous portion. (c) The tube is slowly advanced until the white cuff crosses the glottis. Next, the tube is rotated 90° clockwise to guide the tube tip into the left main bronchus. (d) The tube is located in the proper positionFinancial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.