FKWO pharyngolaryngoscope

Historical Context and Evolution

The FKWO (Feyh-Kastenbauer-Weinstein-O’Malley) pharyngolaryngoscope is the evolution of the original Feyh-Kastenbauer (FK) retractor. The FK, introduced in the late 20th century, was meant to improve the surgical access to the hypopharynx, larynx, and base of the tongue. It was designed when the transoral approach became more ambitious because of the description of Transoral Laser Microsurgery (TLM). Designed with a non-tubular frame, it allowed for broader instrument mobility compared to traditional laryngoscopes, which often had restricted apertures. The FK’s innovative features included interchangeable blades for various surgical scenarios, integrated suction, and enhanced visualization for upper aerodigestive tract surgeries. Learn more on the historical evolution on a previous post.

This tool became a staple for transoral robotic surgery (TORS). Despite its utility, the FK had limitations in accommodating robotic arms and cameras during TORS​. In response to these limitations, the FK was modified into the FKWO by Weinstein and O’Malley to optimize it for robotic systems like the da Vinci platform. The FKWO introduced a wider aperture, additional blade configurations for specific tasks (e.g., supraglottic surgeries), and improved integration with fiberoptic lighting and suction systems.

See the US patent (Provisional application No. 61/459,615, filed on Dec. 15, 2010 by the University of Pennsylvania), which includes the rationale for use.

Description of the FKWO

The FKWO pharyngolaryngoscope is tailored for TORS procedures, although it perfectly fits other transoral techniques. It consists of a rectangular frame with adjustable retraction blades. This flexibility enables individualized retraction of tissues, improving exposure to hard-to-reach areas such as the larynx and base of the tongue.

Features include:

1. Blade Variety: Includes specialized blades for the oral cavity, hypopharynx, and larynx, allowing precise access to target sites without compromising surrounding structures.
2. Fiberoptic Illumination and Suction Integration. Integrated lighting enhances visualization, particularly in deep, narrow operative fields. It is meant for positioning, but ENT surgeons usually prefer the headlight. Built-in suction systems maintain a clear field by managing surgical plume and secretions. Also, is usual clinical situations suction is usually performed alternatively bu the assistant surgeon.
3. Compatibility with Robotic Systems: The widened aperture and ergonomic blade designs ensure seamless interaction with robotic arms and cameras. Still the instrument in the right tends to collide with wheel to adjust the length of the blade, and the endoscope with the tail of the blade. Expertise is required to manage this problems.

Current situation

The device was originally manufactured by Gyrus Inc.. The company was later acquired by Olympus. Olympus took advantage of owning a full set for transoral endoscopic surgery: the FKWO, the endo-eye (an adjustable endoscope with 3D options) and the thunderbeat, an advanced energy device combining harmonic and advanced biopolar energies. Transoral endoscopic surgery coexisted with TORS.

The current problem, since 2024, is that, for reasons not fully clarified, but said to be related to a shift in the regulatory framework, Olympus discontinued the production of the FKWO. The FKWO is far from perfect, but is was the original one; TORS experience worldwide is based on it. Also, it is the less bad of the available options. The problem posed by this situation is still unsolved.

System components

Updated february 8, 2025