Comparing mechanical effects and sound production of KTP, thulium, and CO2 laser in stapedotomy

Thulium laser in stapedotomy surgery

BACKGROUND

Thulium laser use in stapedotomy surgery is usually associated with many doubts regarding the thermal effect on the vestibular area and the production of acoustic shock waves, which may result in permanent complications.

OBJECTIVES

We aimed to evaluate the efficacy and safety of the Thulium laser use in stapedotomy and its long-term effects on the clinical and audiological results.

MATERIAL AND METHODS

It was a retrospective randomized case-series study. We included 148 otosclerosis patients. They were divided randomly into two groups; group A (multiple shots) included 62 patients and group B (one shot with a manual perforator) included 86 patients.

RESULTS

There was a statistically significant improvement of the ABG in both groups. ABG closure (<10 dB) occurred in 87.1% of patients in group A, and 89.5% of patients in group B. Intraoperative complications were more in group B (p-value = 0.038). The postoperative complications were more in group A (p-value = .017).

CONCLUSIONS

According to our experience on a relatively large number of cases, the Thulium laser is a safe tool to be used in stapedotomy either in multiple shots or one shot with a manual perforator. It improved functional hearing efficiently without showing signs of inner ear impairment.

Revision Stapedotomies: the Role of Periprosthetic Scar Tissue Formation in the Development of Unsatisfactory Hearing Results after Stapedotomy

Introduction  Revision stapes surgeries are difficult to perform, and their audiological results are inferior to primary surgeries.

Objective  Our goal was to identify the most common and most influential postoperative reasons that cause persistent air-bone gap (ABG) after the primary surgery. Our focus was concentrated on the mechanical dysfunctions in the middle ear, with special regard to postoperative adhesion formation.

Methods  We performed a retrospective case series study with 23 cases that underwent revision stapedotomies.

Results  A significant improvement was seen in ABG and air conduction levels after surgery. The periprosthetic adhesion formation was seen in 65% of the cases, and it was the primary cause behind the unsatisfactory hearing result in 30% of cases. There was no significant difference in the level of persistent ABGs after the primary surgery, in case of the intratympanic adhesion presence, compared with the presence of other surgical failures. Concerning hearing and ABG gain after revision surgery, the non-inferiority of the negative effect associated with adhesion was shown compared with the other reasons.

Conclusion  The revision stapedotomy is an efficient treatment option in case of persistent ABG. Periprosthetic adhesions are the most common intratympanic reasons for compromised audiological outcomes after stapedotomy.

Adhesion formations have the same negative effect on ABG development as any other surgical failure, and the revision could be more challenging in these cases. These findings highlight the use of the most atraumatic surgical technique and preservation of intact intratympanic mucosa during middle ear surgery.

Mid-term evaluation of perioperative i.v. corticosteroid treatment efficacy on overall and audiological outcome following CO2 laser stapedotomy: a retrospective study of 84 cases

Purpose

Our aim was to determine whether perioperatively administered corticosteroid treatment has any beneficial effect on the outcome of stapes surgery, with special regard to the audiological results and early postoperative morbidity.

Methods

84 CO₂ laser stapedotomies performed in our institute between 2013 and 2018 were included in our investigation. All cases underwent preoperative and mid-term postoperative pure-tone audiometric evaluation. Vestibular complications were also evaluated. The cases were subdivided into two groups, 23 patients received perioperative i.v. methylprednisolone treatment (“S”) while the other 61 patients (“nS”) did not receive any adjuvant pharmacological therapy. The data were analyzed retrospectively using IBM SPSS Statistics.

Results

CO₂ laser stapedotomy proved to be a successful intervention with a significant improvement in ABG and AC thresholds as well. Long-term BC levels were significantly better compared to preoperative ones in the S group; however, in the nS group, no difference could be shown. Hearing and ABG gain were significantly superior in group S [28.1 dB (SD11.2) vs. 18.1 dB (SD 10.9) and 23.9 dB(SD 9.8) vs. 17.2 dB (SD 9.5), respectively].

Conclusion

No significant inner ear damage was detectable in the results of our CO₂ laser stapedotomy method; however, the positive effect of corticosteroid treatment could be demonstrated through the postoperative hearing levels. We found no statistical difference in early postoperative morbidity. According to our data, the routine administration of corticosteroids during stapes surgery could be an issue worthy of consideration. The effects of perioperative treatment vs that on the first day after surgery, and topical vs. systemic treatment could be the subject of further investigation in a prospective manner.

A 1,470 nm diode laser in stapedotomy: Mechanical, thermal, and acoustic effects

BACKGROUND AND OBJECTIVES

Multiple laser systems have been investigated for their use in stapes surgery in patients with otosclerosis. The diode 1,470 nm laser used in this study is an attractive laser system because it is easily transported and relatively inexpensive in use. This wavelength has relative high absorption in water. This study aimed to investigate the mechanical, thermal, and acoustic effects of the diode 1,470 nm laser on a stapes in an inner ear model.

MATERIALS AND METHODS

Experiments were performed in an inner ear model including fresh frozen human stapes. High-speed imaging with frame rates up to 2,000 frames per second (f/s) was used to visualize the effects in the vestibule during fenestration of the footplate. A special high-speed color Schlieren technique was used to study thermal effects. The sound produced by perforation was recorded by a hydrophone. Single pulse settings of the diode 1,470 nm laser were 100 ms, 3 W.

RESULTS

Diode 1,470 nm laser fenestration showed mechanical effects with small vapor bubbles and pressure waves pushed into the vestibule. Thermal imaging visualized an increase temperature underneath the stapes footplate. Acoustic effects were limited, but larger sounds levels were reached when vaporization bubbles arise and explode in the vestibule.

CONCLUSION

The diode 1,470 nm laser highly absorbs in perilymph and is capable of forming a clear fenestration in the stapes. An overlapping laser pulse will increase the risk of vapor bubbles, pressure waves, and heating the vestibule. As long as we do not know the possible damage of these effects to the inner ear function, it seems advisable to use the laser with less potential harm. Lasers Surg. Med. 49:619-624, 2017. © 2017 Wiley Periodicals, Inc.