[Laryngeal surgery with a 3-D technique. Early results with the jet-laryngoscope in superimposed high-frequency jet ventilation].

Surgery by three-dimensional (3D) endoscopy is being used routinely in abdominal surgery and, in special cases, in thoracic surgery; however, it has not been reported as being used in microlaryngeal surgery. METHODS. We inserted a 3-D endoscope into a jet laryngoscope and studied the pressure properties at the tip of the laryngoscope as well as intrapulmonary pressures while applying superimposed high-frequency jet ventilation. The studies were conducted initially using a lung simulator, and then in seven patients undergoing microlaryngeal surgery. RESULTS. Due to the rather large 3-D endoscope, the diameter of the jet laryngoscope was reduced by between 25.2% and 70.9%, depending on its size. The measurements on the lung simulator revealed that reduction of laryngoscope diameter leads to an increase in the following parameters: expiratory resistance, tidal volume, and peak inspiratory pressure. The mean FiO2 was 0.74 +/- 0.1; the mean paO2 was 169.2 +/- 80.4 mmHg; and the mean paCO2 was 40.9 +/- 2.4 mmHg. The mean airway pressure was 19 +/- 5.3 mmHg prior to insertion of the endoscope and 12.3 +/- 6.9 mmHg after insertion. The mean positive end-expiratory pressure values increased from 2 +/- 0.6 to 3.6 +/- 2.3 mmHg. Reduction of the working pressure resulted in restoration of the initial inspiratory pressures and tidal volumes. CONCLUSIONS. In the clinical application of 3-D endoscopy via a jet laryngoscope, it was possible to achieve sufficient ventilation, inspection of the surgical field, and performance of the surgical procedure. A CO2 laser was used without changing the ventilation regime. Although technical alterations would be desirable for its application to microlaryngeal surgery, it is presently possible to safely use the 3-D endoscope via the jet laryngoscope for microlaryngeal surgery, presenting the surgeon with new possibilities in voice-improving microsurgery of the larynx.