[3-D endoscopy for laryngeal interventions in tubeless superimposed high frequency jet ventilation. A clinical trial]

Surgery by 3-dimensional (3D) endoscopy is being used routinely in abdominal surgery and, in special cases, in thoracic surgery; however, it has not been reported to be used in laryngeal surgery.

We inserted a 3-D endoscope into a jet laryngoscope and studied the pressure properties at the tip of the jet laryngoscope as well as the intrapulmonary pressures while applying SHFJV. The studies were conducted initially using a lung simulator, and then in 6 patients undergoing endoscopic laryngeal surgery.

Due to the rather large 3-D endoscope the diameter of the jet laryngoscope was reduced between 25.2% and 70.9% depending on the size of the jet laryngoscope. The measurements on the lung simulator revealed that the reduction of the diameter of the jet laryngoscope 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 airway pressure was 19 +/- 5.3 mmHg prior to the insertion of the endoscope and 12.3 +/- 6.9 mmHg after the insertion. The mean PEEP values increased from 2 +/- 0.6 to 3.6 +/- 2.3 mmHg. Reduction of the working pressure resulted in regaining the initial inspiratory pressures and tidal volumes.

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.(ABSTRACT TRUNCATED AT 250 WORDS)