Use of Lasers in Otosclerosis Surgery

Effect of Bending of Carbon Dioxide Laser Fibers on Power Output

Objective

The power output from carbon dioxide (CO₂) laser fibers has the potential to be diminished if there are any bends along its course, which may alter the effect the laser has on the target tissue. In this study, we assess how bending of CO₂ laser flexible fiber assemblies affects the energy output measured at the end of the fiber.

Study Design

Laboratory study.

Setting

Laboratory.

Methods

Eight separate flexible fibers were tested—4 were of a type commonly used in endoscopic airway procedures, and the other 4 were a type used in otologic surgery. Fibers were bent in various configurations, and the power output of a CO₂ laser fired through the bent fiber was measured. The output through the bent fiber was normalized to the output with a straight fiber. Correlations between bend parameters and power outputs was tested using Spearman’s correlation coefficient.

Results

For the airway fibers, there was a weak trend toward increasing energy outputs with greater radius of curvature (P = .714) and a negative correlation between the energy output and arc of rotation (P = .043). For the otologic fibers, there was a trend toward increasing energy outputs with greater radius (P = .084) and a strong negative correlation between the energy output and the arc of rotation (P = .006).

Conclusion

CO₂ laser energy output is reduced by bending of the laser fiber assembly. When using the CO₂ laser fiber, surgeons should be aware of any bends in the fiber and are encouraged to take measures to minimize bending.

Otosclerosis – analysis of factors influencing the improvement of hearing after surgical treatment

<b>Introduction:</b> Otosclerosis is a disease that occurs only in humans, in the course of which there are foci of pathological ossification in the temporal bone. The etiology of the dise ase is not fully understood. Treatment of the conductive component of hearing loss is surgical. The results of the treatment are influenced by factors related to the surgery, the local condition of the middle ear and the function of the inner ear. </br></br> <b>Aim:</b> The aim of the study is to identify factors influencing the improvement of hearing in patients treated surgically due to otosclerosis. </br></br> <b>Material and methods:</b> The study included patients who underwent otosclerosis for the first middle ear surgery and under-went stapedotomy. Considering the factors that may affect the outcome of surgical treatment, the patients qualified for the analysis were divided into subgroups. All patients underwent a medical history and physical examination of otorhinolaryn-gology and a complete set of audiological examinations. </br></br> <b> Results:</b> A statistically significant reduction in cochlear reserve was observed in all patients after stapedotomy. The be-neficial effect of the performed treatment on the improvement of threshold values of bone conduction in patients with mild sensorineural hearing loss was also confirmed. Intraoperative removal of adhesions present in the tympanic cavity significantly improved hearing in terms of bone conduction values, especially at 500 Hz. </br></br> <b> Conclusions:</b> (1) The conducted study confirmed the influence of factors related to the local condition of the middle ear lining on the final result of otosclerosis surgery; (2) Audiometric markers of cochlear otosclerosis, observed before surgical treat-ment, are an unfavorable factor in the improvement of hearing after the performed treatment.

Conventional approaches versus laser CO2 surgery in stapes surgery: a multicentre retrospective study

PURPOSE

To analyze and compare surgical and audiological outcomes of conventional approaches versus laser CO2 surgery in stapes surgery.

METHODS

333 patients who underwent stapes surgery were enrolled in the study; the patient population was divided into three groups: group 1: 170 patients treated with conventional stapedotomy with manual microdrill (average age 49.13 years); group 2: 119 patients treated with conventional stapedotomy with electrical microdrill (average age 51.06 years); group 3: 44 patients (average age 50.4 years) who underwent CO2 laser stapedotomy. Intra-operative, postoperative outcomes and audiological results were investigated.

RESULTS

The average surgical time of laser CO2 surgery was longer than for other surgical procedures. No statistical differences emerged in post-operative abnormal taste sensation. There was also no difference in postoperative dizziness. Air-bone gap (ABG) went down from 29.7 ± 10 dB (group 1) and 27.32 ± 9.20 (group 2) to 10 ± 6.9 dB (group 1) and 10.7 ± 6.03 dB (group 2). In group 3 the preoperative ABG was lowered from 28.3 ± 10.1 to 11.8 ± 10.9, with a statistical difference in auditory recovery (p = 0.0001); The group of patients treated with laser CO2 showed a percentage of patients with an ABG closure of between 0 and 10 dB higher than in the group treated with manual microdrills (77.2% vs. 60%, respectively; p = 0.03).

CONCLUSION

Overall surgical results of CO2 laser and conventional stapedotomy are comparable without any significant difference; however, the group treated with CO2 laser appears to have a percentage of patients with an ABG closure 0-10 dB higher than the group treated using the conventional technique.

The clinical characteristics of otosclerosis and benefit from stapedotomy: our experience of 48 patients (58 ears)

Background: Stapedotomy has been proved to be one of the most efficient procedure to treat otosclerosis, various factors contribute to the diversity of the outcomes and controversial results exist from previous studies. Objectives: We evaluated clinical characteristics and outcomes of stapedotomy, as well as possible predictive factors of a successful outcome. Materials and methods: This retrospective study evaluated 58 ears from 48 patients with demographic data, plus short-term follow-up of hearing outcomes of 28 ears, and evaluated variables using univariate general linear regression analyses. Results: The average operation age was 41.54 years. A total of 87.5% (42/48) patients presented with bilateral otosclerosis. 39.66% (23/58) ears had CT finding before the surgery. Patients with persistent tinnitus accounted for 53.45% (31/58) and the average preoperative ABG of the 58 ears was 32.22 dB. We achieved good postoperative air-bone gaps (ABGs) overall but poor ABG closure at 4 kHz. No predictive factors were identified in the 28 ears that were followed up. Conclusions and significance: Delayed surgery may be attributable to insufficient recognition of otosclerosis. The fenestration size could be the reason for poor ABG closure at high frequency. However, more cases and longer follow-ups are required to confirm our findings.