In the 1960s, Dingman and Grabb [7] at the University of Michigan described a new, closed-frame retractor system to allow for improved visualization of the oral cavity and oropharynx. The Dingman gag includes not only the tongue retraction blade but also attachments to the lateral portion of the frame allowing for retraction of the cheeks. There are also springs on the inferior and superior portions of the frame to capture sutures that are placed through the palate or tongue for additional points and vectors of retraction (Fig. 6.2). This wide view and flexibility of retraction has made it a staple in surgery on the palate, primarily cleft surgery [8].

Again, given its wide availability and familiarity, the Dingman retractor has been adapted for use in TORS. Similar to the Crowe-Davis and McIvor, exposure of the oropharynx is excellent, although the closed frame restricts the motion of the robotic arms and camera. This limitation further increases as the surgeon moves to the base of tongue lesions and into the hypopharynx and larynx. There are few tongue retractor options with these systems, limiting the ability to obtain direct exposure of the base of tongue.

Given these restrictions, Hockstein et al. [9] describe a series of cadaveric dissections using the Dingman retractor, from laryngeal procedures such as vocal cord stripping and cordectomy to the base of tongue resections. In addition to the tongue and cheek retractors, retraction stitches through the oral tongue as well as the epiglottis are used and attached to the retractor to improve the field of view.

The Feyh-Kastenbauer (FK) retractor (Gyrus Medical Inc., Tuttlingen, Germany) is a versatile retraction system with unique applications in laryngeal, hypopharyngeal, and base of tongue procedures. The retractor features a closed rectangular frame, cheek retractors, tongue blades, laryngeal blades, and a vallecular blade [5]. The FK retraction system offers a variety of tongue blades with the ability to adjust both insertion depth and insertion angle. Some of these blades also offer the unique feature of “cutout” components designed for use in conjunction with the angle and depth adjustments to provide improved exposure of more distal operative sites (Fig. 6.3).

O’Malley and colleagues were one of the first groups to demonstrate the unique advantages offered by the FK retractor in TORS procedures of pharyngeal and base of tongue pathologies. In comparison to the Dingman and Crowe-Davis retractors, the FK is advantageous in base of tongue surgery as it provides a larger rectangular opening for the widest instrument working space with more space for robotic instrument movement. The two small articulating clamps of the FK allow for individualized articulation of each of the tongue and cheek retractor blades to be attached and manipulated for increased tissue exposure. The FK also includes integrated suction retractors that are not available in many other retraction systems. Modifications were made to the original FK retractor system by Weinstein and O’Malley, in order to optimize the retractor for use in conjunction with the da Vinci system, now named the FK-WO (Feyh-Kastenbauer Weinstein-O’Malley) [10]. These modifications included widening of the aperture at the frame to allow for more room for instruments and the camera, as well as new blades for exposure of the supraglottis (Fig. 6.3), making it useful in all transoral procedures.

In base of tongue cadaver studies, O’Malley and colleagues [5] determined that the FK had significant advantages with its lateral retractor attachments, a variety of tongue blades with and without cutouts, vallecular blade, cheek retractors, and three-dimensional adjustment capability that deemed it the most versatile retraction system at the time. Thus, it was chosen for use in the human base of tongue resections. The open laryngeal blade fit into the vallecula and provided visualization of the junction of the base of tongue and epiglottis, allowing for controlled inferior tissue incisions.

The FK retractor allows for TORS of the base of tongue, eliminating the requirement of mandibulotomy with a lip-split or transpharyngeal approaches that carry high risk of damage to delicate structures, with effects on mastication, swallowing, speech function, and cosmesis.

The FK retraction system is also the only retractor that has been reliably used for supraglottic partial laryngectomy and hypopharyngeal tumors as it is capable of exposing the larynx, a weakness of the Dingman and Crowe-Davis. In 2007, Weinstein and colleagues successfully utilized the FK retractor system for completion of supraglottic partial laryngectomies [11], and Park and colleagues describe the excision of supraglottic and glottic lesions in 2009 [12].

The laryngeal advanced retractor system is a newer design that was introduced to the field of TORS in 2011 by Remacle and colleagues [13]. The retractor features a rounded frame with blades that allow adjustment of both insertion depth and insertion angle, cheek retractors, tongue blades, and laryngeal blades [14]. The curved frame adapts to the shape of the patient’s face and contains framework that extends in the horizontal plane to allow for ease of movement of the robot arms. There is also a ratchet system that is built into the frame to assist with vertical suspension of the device, a feature of standard laryngoscopes that is not available in other retractor systems (Fig. 6.4).