A New Device for Treating Laryngeal Carcinoma Using Microdissection Electrodes

Abstract

For the last 3 years, we have been using microelectrodes (ME) for endoscopic electrosurgery to resect T1 tumors of the vocal cords. A first report presented early results of this surgical technique.1 Our experience has been extremely satisfactory and has been widened to include a greater number of cases and more advanced tumors. This article reports our experience using ME with a new angled handpiece to treat T1 and T2 laryngeal tumors. In this series, we discuss the new device developed to exclude the surgeon's hand from the field of vision. Seventeen patients with T1–T2 stage larynx carcinoma based on the 1997 staging system established by the AJCC/UICC were selected. Eight tumors were located in the glottic larynx (T1) and nine T2 glottic tumors with supraglottic or subglottic extension. All patients had mobile vocal cords and were N0. A diagnostic biopsy confirming squamous cell carcinoma was obtained either by previous microsurgery or by extemporaneous evaluation. Two senior surgeons operated on all of the patients. The follow up ranged from 6 to 13 months. All the patients were males, ranging in age from 38 to 75 years (median, 57 years). The anesthetic endotracheal tube was the same as that used in CO2 laser surgery because of the risk of fire associated with the use of electrosurgical instruments.2 The types of cordectomies were in accordance with the classification proposed by the European Laryngological Society in 2000.3 We performed eight transmuscular cordectomies, two extended cordectomies, and seven supraglottic resections. No neck dissection was performed. As we describe elsewhere,1 the surgical procedure begins with conventional direct suspension laryngoscopy. The same set of laryngoscopes used for CO2 laser surgery is used for this technique. The remaining hand instruments are microforceps and a suction tube used for conventional microsurgery. An excision is made using an ultrafine tungsten microelectrode (ME) (Cotswold; Prima, EC) connected to a handpiece, which we developed (made by Ciruval EC), that acts as an angled extension. The handpiece is made of stainless steel (AISI 316L; ThyssenKrupp, EC) and measures 140 mm in length and 2.5 mm in diameter, and is covered with thermoretractile insulation BPX with a temperature resistance of between −55°C and 125°C. This handpiece is connected to the electrosurgical generator, a Valleylab Force 2 electrosurgical generator (Pfizer, EC) set to an output power of 25 to 30 W in cut and coagulation modes (Fig. 1., Fig. 2.). The angle of the handpiece allows the surgeon's hand to be kept out of the line of view (Fig. 3). Microelectrode set. From bottom to top: handle of the electric scalpel, handpiece presented in this report, tungsten needle. Assembled microelectrode set. The white arrow indicates the tungsten needle. The broad arrow points to the original handpiece. The black arrow indicates the handles of the electric scalpel. The position of the hands results in a perfectly clear field of vision free of obstructions. To perform the cordectomies, the false vocal cord is resected first. Once the vocal cord is exposed, traction on the vocal cord toward the midline allows it to be sectioned cleanly using the ME (Fig. 4). Microelectrode sectioning of the vocal cord. The broad arrow indicates the suction tube. The asterisk denotes the section field and the fine arrow points to the tungsten needle. To perform supraglottic resection, the laryngoscope is held toward the tongue base allowing full view of the vallecula. The resection of the epiglottis with the ME is extremely clean and quick. Starting the resection in the glossoepiglottic fold, a deep section is made toward the anterior edge of the preepiglottic space to capture its fat with the epiglottal specimen. The aryepiglottic fold is then sectioned toward the false vocal cord depending on the extension of the tumor. Fig. 5., Fig. 6. show the procedure used to resect a T2 vocal cord tumor extending to the subglottis. The resection is always made in cut mode, because it produces less tissue damage than the coagulation mode.1 The coagulation mode is used when hemostasis is necessary. Resection of a T2 vocal cord tumor with subglottic involvement. The arrow indicates the internal face of the thyroid cartilage uncovered as the tumor is removed (asterisk). The same case as in Figure 5. Once the excision is complete, the cricothyroid membrane (white asterisk) and upper border of the cricoid cartilage (black asterisk) can be seen. The arrow indicates the internal face of the thyroid cartilage. Note the minimal carbonization of the surgical field in Fig. 4., Fig. 5.. All the procedures were approved by the Institutional Review Board. No immediate postoperative complications were observed in any of the patients. All the patients with T1 tumors were able to eat a soft diet the day after the operation. The patients with a T2 supraglottic tumor were fed orally between the third and fourth day after the operation. Those with a tumor with subglottic extension started oral feeding within a maximum of 2 days. None of the patients required tracheostomy, and all received postoperative attention similar to that given patients after CO2 laser surgery. The functional results with ME in this series were identical to those observed in our previous series.1 Currently, we are evaluating voice quality in patients with T2 tumors using the grade, roughness, breathiness, asthenia, and strain (GRBAS) scale. Based on our observations, endoscopic supraglottic resection with ME produces changes in voice quality and deglutition similar to those observed with CO2 laser techniques (unpublished data). It is not the aim of this article to present oncologic results, because the intention of the authors is to describe the benefits of the angled device used. In all cases, however, the resection margins were tumor-free on histology, and all patients are presently alive and free of disease. Microelectrodes are useful for resecting T1–T2 laryngeal carcinomas. The main advantages are excellent hemostasis and the view of a tidy and well-defined surgical field. The speed of the technique and low cost of the equipment, when compared with CO2 lasers, are other advantages. The tissue damage is no greater than with laser injury.1, 4 This new device is very useful in this type of surgery because it keeps the surgeon's hand out of the line of view, facilitating the resection. In fact, based on our experience, we believe that all tumors that are resectable with a CO2 laser can be advantageously resected with ME.