Temperature rises in the round window caused by various light sources during insertion of rigid endoscopes: an experimental animal study.

OBJECTIVES: The instruments used in endoscopic surgery include rigid endoscopes of different diameters and angles, sources of light and monitors. In this study, we explored temperature rises in the round window caused by insertion of rigid endoscopes of different diameters into the middle ear; the endoscopes were fitted with different light sources. DESIGN: An experimental animal study. SETTING: We subjected seven guinea pigs to simulate otological surgery at room temperature. We monitored body temperatures, along with temperature rises caused by the use of 0° rigid endoscopes of diameters 3 or 4 mm, fitted with light sources including a halogen light, a light-emitting diode (LED) and a xenon light. Data were collected every second from a sensor placed in the round window. PARTICIPANTS: An experimental study on 7 guinea pigs. MAIN OUTCOME MEASURES: Rise of the temperature on round window. RESULTS: Rigid endoscopes caused the temperature of the tympanum to rise when xenon and halogen light sources were used, regardless of endoscope diameter. However, the temperature rise was less when a LED light source was employed. CONCLUSION: The endoscopic instruments used in middle ear surgery caused the temperature of the round window to rise. The rise varied with endoscope diameter and the type of light source used.

A new approach for cerumenolytic treatment in children: In vivo and in vitro study.

OBJECTIVES: To demonstrate the effects of various cerumenolytic solutions in vivo and in vitro and to measure the change in pain following treatment. METHODS: The study was done as a single-centre, prospective and double-blind study. Among 1243 paediatric patients with total or nearly total occlusive plug in 4 years period, those who accepted endoscopic ear examination and cleaning via aspiration after a follow-up period of at least 10 days following treatment were included in the study. Day of total TM visualisation was noted and removal co-efficient was calculated. The pre and post-treatment pain levels of the patients were assessed using analogue chromatic continuous scale (ACCS). In the in vitro part, cerumen samples collected at equal amounts from 20 patients were treated at 36-400°C in 6 different tubes with the same solutions and their dissolution degrees were assessed over a period of 5 days (Hour 6, Hour 12, Hour 48, Hour 72, Hour 92, Hour 120). Additionally, the degree of resolution in the tube treated with distilled water was considered to be the control reference. RESULTS: In the in vivo part of the study, total TM visualisation was observed in Group 1 at 50.2% (Day 3), in Group at 57.1%, in Group at 62.3%, in Group at 44.3% and in Group 5 at 73.5%. The group with the lowest removal co-efficient was Group 5 (removal co-efficient=1.623). In reference to the ACCS pain scores of the patients, the intra-group change pre-post treatment was found statistically significant for all groups (p=0.008; p=0.0222; p=0.005; p=0.026; p=0.018). After statistical analysis between the groups the difference between Group 5 and other groups was found statistically significant (p=0.002; p=0.026; p=0.044; p=0.034). In the in vitro part of the study, the best dissolution was observed in Group 2. CONCLUSIONS: In our study, the best cerumenolytic solutions were identified to be glycerine 10cc+3% hydrogen peroxide 10cc+10% sodium bicarbonate 10cc+distilled water 10cc. Especially the use of this mixture ease in terms of pain for the patient and in terms of time and comfort for the physician during the removal procedure.