A nonrandomized comparison of the thulium laser and the CO₂ laser in primary stapedotomy for otosclerosis

Objective: Comparing hearing results in patients with otosclerosis treated with laser-assisted stapedotomy using the 2-μm thulium laser or the CO₂ laser.

Study design: Prospective nonrandomized clinical study.

Setting: In a tertiary referral center in France (Jean Causse Ear Clinic, Béziers), 208 primary stapedotomies were performed in 204 patients between March 2008 and November 2009. Sufficient follow-up data were available for 194 procedures.

Methods: The fenestration in the footplate was made with the thulium laser in 98 procedures and with a flexible CO₂ laser in 96 procedures. Preoperative and postoperative audiometric results were compared. Side effects, such as vertigo and tinnitus, were scored.

Results: Patients treated with the CO₂ laser had better hearing outcome compared with those treated with the thulium laser at both 3 and 12 months of follow-up. At 3 months, the success of the surgery, defined as closure of the air-bone gap to within 10 dB, was 90.0% in the thulium group compared with 96.8%in the CO₂ group. Bone conduction shift showed an overall deterioration of 1.6 dB (standard deviation, 6.9 dB) in the thulium group compared with an improvement of 1.3 dB (standard deviation, 4 dB) in the CO₂ group. In the thulium group, there were four patients with sensorineural hearing loss (4.4%) and three with tinnitus (3.1%) compared with none in the CO₂ group.

Conclusion: Stapedotomy surgery performed with a fiber-delivered thulium laser resulted in a higher chance of inner ear damage measured by bone conduction shift compared with the use of a fiber-delivered CO₂ laser. We advise not to use the thulium laser for stapedotomy.