Through the use of fiberoptic light and image bundles, optical stylets permit the user to obtain a view from the distal end of the endotracheal tube (ETT). The stylets allow direct visualization of structures at the tip of the tube as it is inserted, simplifying intubation when a poor laryngoscopic grade is encountered and facilitating confirmation of tube placement (Figs. 21-1, 21-2, 21-3 and 21-4). Because of the bright light at the tip of the device, the optical stylet can also act as a lightwand if visualization through the optics is poor. These devices require the operator to look through an objective lens as the device is inserted into the airway. Optical stylets are frequently used in conjunction with direct laryngoscopy, or a jaw thrust, elevating the mandible and tongue for optimum visualization. In essence, this is a simpler and less expensive version of the fiberoptic intubating bronchoscope.

There are multiple types of optical stylets in use. Some of the most common include the Shikani Optical Stylet, the Levitan (First Pass Success or FPS) Optical Stylet, and the Bonfils Retromolar Intubation Fiberscope. These optical stylets are used in different situations and the insertion technique differs among the classes.

The Shikani Optical Stylet (Clarus Medical, Minneapolis, MN), like the lighted stylet and the other optical stylets discussed below may be used for routine airway management. In addition, this device is useful for situations in which a difficult airway is anticipated or in urgent situations when a patient presents an unanticipated challenging or difficult airway (as long as ventilation is successful and the patient is not hypoxemic). Referred to as a “seeing bougie,” the Shikani stylet is a malleable device that is able to conform to the patient’s airway.

The Levitan FPS Optical Stylet (Clarus Medical, Minneapolis, MN) is a device that is intended for use in concert with direct laryngoscopy, when little or none of the glottic opening can be visualized. It has a shorter tube length to allow the ETT to be fitted directly to the device without the need for a tube stop and requires cutting off the ETT to 28 cm in order to fit onto the stylet. This short length facilitates ready positioning of the device in front of the operator’s eye during the process of direct laryngoscopy when a challenging view is evident. There is a site for an oxygen connector to insufflate oxygen. Lightwand-like transillumination is also available as well.

The Bonfils Retromolar Intubation Fiberscope (Karl Storz Endoscopy, CA) was derived from the work of Bonfils¹ in which he described an approach from a very lateral position, behind the molar teeth, to intubate children with Pierre Robin syndrome. The device is a traditional rigid optical stylet with a fixed 40° angulation at the distal end, which can be illuminated by either a remote or attachable (battery-powered) Xenon light source. The smallest version allows placement of a 4.0 mm internal diameter ETT.

Another device, the Sensascope (Acutronic MS, Hirzel, Switzerland), combines some features of an optical stylet and a fiberoptic scope. The Sensascope has a rigid, S-shaped shaft that is 6 mm in diameter, with a distal, 3-cm steerable tip, as well as a built-in camera and LED light source. The image is displayed on a separate video monitor, rather than observed through an eyepiece. For optimal function, the device is recommended to be used with direct laryngoscopy to retract the tongue and soft tissues before insertion into the pharynx.

Some seeing-stylet type devices do not have the rigidity of the above devices but nonetheless allow visualization of the anatomy at the tip of an inserted ETT. The “Pocket Scope” (Clarus Medical, Minneapolis, MN) is a flexible, 42 cm shaft that is 3.3 mm in diameter and which is illuminated by an attachable “green line” laryngoscope handle. The device is used to rapidly confirm the placement of an ETT or a double lumen ETT, with less complexity and expense than a standard fiberscope. Because of its flexibility, it would not be particularly useful for intubation in a difficult airway situation. The Tracheoscopic Ventilation Tube (TVT, ET View, Misgav, Israel) is an ETT, available in sizes 7, 7.5, and 8 mm internal diameter, with a miniature camera and light source imbedded at the distal tip, which connects to a video monitor. It permits ready confirmation of ETT placement and continuous monitoring of ETT position in the airway. In addition, this device facilitates viewing the glottis in the setting of unfavorable anatomy during direct laryngoscopy and, with the maneuverability afforded by a standard stylet in the tube, would permit one to steer the tube more effectively to the glottic opening.

Optical stylets have been used for difficult and routine intubation in the operating room (OR).²,³,⁴ The optical stylet has not been subjected to controlled, comparative studies in the management of the difficult airway. At the same time, in small series, it has proven useful for airway management in the OR. In a study of 32 patients undergoing elective anesthesia for surgery, 94% of cases were intubated successfully on the first attempt and the remainder on the second attempt using this device.³