4.1
The exoscope in transoral laryngeal surgery
4.1.1
Background
The recent development of exoscopic systems was first aimed for surgical recording and teaching purposes. Then, the implementation with 3D cameras, 4K resolution, and ergonomic holders have driven increasing interest in their application for direct surgical view. In the head and neck field, several applications have been tested, including otosurgery, otoneurosurgery, microvascular anastomosis, and transoral oropharyngeal surgery. These studies have demonstrated the easy use of the exoscopic camera as a magnifier, without any coupling system for the correct use of a cutting device paired with the viewing system. In all clinical scenarios tested, the exoscopic camera presents the advantage of video recording for teaching purposes and the possibility for the entire surgical team to get the same 3D view of the main surgeon. Moreover, the surgeon’s ergonomics was improved compared to conventional microsurgery.
The idea of replacing the operating microscope during transoral laryngeal microsurgery, , introduced the issue of how to combine a CO 2 laser micromanipulator, not yet available for the previously proposed exoscopic systems. For this reason, in collaboration with the engineers of the Italian Technology Institute (IIT) we developed a coupler device suitable for the use of the free-beam CO 2 laser micromanipulator combined with a 3D-HD exoscopic system. ,
4.2
Our experience: the road toward a feasible exoscope-TLM setting
4.2.1
First prototype holder arm with VITOM 3D
4.2.1.1
Surgical setting
The idea of overcoming the limitations of the operative microscope and fully replicate a transoral laser microsurgery (TOLMS) setting, coupling the free-beam CO 2 laser micromanipulator with the new exoscopic system, radically changed the system of visualization and led to novel difficulties and shortcomings. In fact, the technologies employed were not conceived to be assembled in a transoral microsurgical setting. To make them work efficiently as a whole, several adaptations were needed, especially in terms of stability, paring, and movement.
As an exoscopic system of vision, the VITOM 3D-HD (Karl Storz SE & Co. KG, Tuttlingen, Germany) was employed. Since it was conceived to enhance visualization quality in micro and open surgical procedures, the VITOM 3D-HD was equipped with a thin and lightweight holding system called VERSACRANE LIGHT. While being very compact and wieldy to hold the VITOM in position, the VERSACRANE did not have sufficient stability when the first tests with the laser micromanipulator were carried out. In particular, many vibrations affecting the frame resulted in unstable vision during laser positioning and movements, probably due to the extra weight of the manipulator that the holding system was not designed to support. This issue revealed the necessity to substitute the VERSACRANE with a new holder, specifically conceived to firmly support the weight of the VITOM and micromanipulator simultaneously in a transoral laser microsurgical setting. Thus, a customized support arm ( Fig. 4.1 ) was created in collaboration with the IIT, designed to be mounted on a Zeiss microscope stative, removing the optic system. The holder arm was provided with a handle to allow macroscopic movements and positioning, knobs to lock all joints in place once the definitive position of the support structure was reached, and a specific regulatory wheel for precise adjustments of the framing angle. A specific adaptor plate (model TH004 Micromanipulator Interface VITOM, installation of CO 2 laser micromanipulators on VITOM 3; Karl Storz SE & Co. KG, Tuttlingen, Germany) was designed by IIT engineers and fixed to the holder arm to allow for coupling with the micromanipulator, so that the micromanipulator could be stably fixed in a position aligned with the line of sight of the VITOM 3D-HD.
With this prototype of the exoscope-assisted transoral laser microsurgical setting, the essential requisites for precise alignment between the line of sight of the exoscope through the laryngoscope and laser micromanipulator workspace were achieved. Moreover, the ideal operating distance between the laser scanner and surgical target was precisely established to optimize the “char-free” cutting properties of the laser. The methods followed for these adjustments are thoroughly described in a previous publication.
Besides helping the first surgeon in traditional TOLM with external counterpressure on the larynx and cooperating to a surgical maneuver with suction or other surgical tools, with the exoscopic system the assistant surgeon can constantly follow the procedure on the 3D surgical screen and, if needed, zoom in on a particular target, regulate focus, and slightly move the framing to follow the first surgeon’s maneuvers using the IMAGE1 PILOT control device, directly fixed on the left side of the operating bed (see also Chapter 1 ).
The preliminary results with this novel prototype in alternative to the traditional TOLMS, were obtained in 17 nonconsecutive oncological cases.
4.2.1.2
Adaptability to fiber laser procedures
An additional advantage of this setting can be employed by removing the CO2 laser micromanipulator from its adaptor plate on the VITOM holder arm and using a fiber laser with different wavelength with less precise and char-free cut, but a better control of hemostasis, in relation to the site and type of resection. This offers the simultaneous availability to employ 3D angled telescopes for different indications or different surgical steps of the same procedure.
In our experience, a flexible fiber tulium/diode laser was utilized when the disease involved one of the supraglottic subsites in the presence of extensions to the medial hypopharyngeal wall or to the base of the tongue. During the preparation of this setting, a good suggestion is to move the exoscope slightly away from the laryngoscope/mouth-gag compared to the CO 2 laser setup, thereby offering a wider operative field and avoiding competition between surgical instruments, which is not easily feasible with the standard operative microscope.
4.2.1.3
Issues
Although being comparable to the traditional microscope setting once a good position and framing have been obtained, the currently described prototype setting for CO 2 laser exoscope-assisted transoral procedures was still affected by some stability and movement fluency issues during manual positioning of the holder arm and macroscopic adjustments of the framing. Moreover, the full-HD vision technology employed had been already overcome by other devices equipped with 4K resolution and slightly higher image quality.
4.2.2
Adaptation for the ORBEYE system
4.2.2.1
From full-HD to 4K resolution
The same concept of an exoscope-assisted transoral surgical setting for the larynx was replicated with state-of-the-art technology in terms of vision, the ORBEYE 4K 3D platform (Sony Olympus Medical Solutions, Tokyo, Japan; FDA approved). This exoscope is characterized by one of the highest magnification powers (26× with the 55-in. screen), while maintaining full-size 4K image resolution along the entire range of available enlargements. Furthermore, it is equipped with a motorized support arm that makes its movements fluid, easy to maneuver, and accurate during the framing. The movements of the motorized arm can be controlled manually with simultaneous pressure on three buttons placed at the head of the arm and dragging it into position before the procedure starts. In addition, fine adjustments of the inclination, zoom, and focus of the image can be regulated by a pedal control with other adjunctive commands and customizable shortcuts.
Furthermore, the inclusion of the narrow band imaging (NBI) tool, developed in the gastroenterological setting and now widely used in the upper aerodigestive tract, represents an adjunctive value allowing for real time intraoperative control of the superficial extension of the lesion and margins of resection. In the field of transoral laryngeal surgery, the high magnification power with 4K resolution and excellent lighting and image definition features permit a clear view even in the narrow corridor of a laryngoscope, ensuring precise phonomicrosurgical procedures with cold instruments or fiber laser resections, with better ergonomics.
4.2.2.2
Issues
The transoral setting with the ORBEYE system cannot be coupled with a CO 2 laser micromanipulator at this time, since this would require a specifically designed adaptor plate to be mounted on its motorized arm. For this reason, no transoral CO 2 laser procedure on the larynx can be performed with this setting, representing the most limiting factor to its application in exoscope-assisted transoral laser laryngeal surgery.
4.2.2.3
Adaptability to fiber laser procedures
Nonetheless, the ORBEYE system can fully replace the microscope when the surgeon chooses to use a fiber laser for the resection, particularly for the supraglottic larynx and/or hypopharynx. In this setting, the possibility for the surgeon to use both hands to manipulate laryngeal tissues and surgical instrumentation, while at the same time controlling the frame, zoom, focus, and additional features like NBI with his foot on the pedal represents a real step forward in terms of performance, ergonomics, and surgical experience.
4.2.2.4
Case series
Our experience is derived from a case series of 12 patients successfully treated in September 2019 with the ORBEYE exoscopic system. In particular, seven transoral procedures were performed with fiber laser (three tonsillectomies, three laryngeal tumors, one parapharyngeal tumor), three glottic phonomicrosurgical procedures with cold instrumentation, and two cases of free flap harvesting with microvascular anastomosis ( Fig. 4.2 ).
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
