A Nonrandomized Comparison of Potassium Titanyl Phosphate and CO2 Laser Fiber Stapedotomy for Primary Otosclerosis With the Otology-Neurotology Database

Objectives/Hypothesis: To compare short-term hearing results in patients undergoing laser stapedotomy for primary otosclerosis using either the flexible potassium titanyl phosphate (KTP) or CO2 laser fiber. Study Design: Prospective nonrandomized clinical study at a tertiary referral center. Methods: Two hundred fourteen patients undergoing 214 stapedotomies for otosclerotic stapes fixation were enrolled in this study from January 2008 to January 2009. Comparative analyses were made between a group of 107 patients who underwent stapedotomy with the flexible KTP laser fiber and 107 patients who underwent stapedotomy with the flexible CO2 laser fiber. Preoperative and postoperative audiometric evaluation at 3 months using conventional audiometry, namely, air-bone gap (ABG), bone-conduction thresholds, and air-conduction thresholds, were assessed. Results: In the KTP laser group the postoperative ABG was 4.3 dB compared to 3 dB in the CO2 group, which is a mean difference of 1.3 dB (95% confidence interval [CI], -0.3 to 2.8; P = .10). Of the patients from the KTP group, 92% had a postoperative ABG of 10 dB or less, as compared to 97% in the CO2 group (mean difference 5%; 95% CI, -10 to 1; P = .14). The postoperative ABG at 4 kHz was 4.9 dB; in the KTP and 2.2 dB in the CO2 group, which is a mean difference of 2.7 dB (95% CI, 0.6-4.7, P = .01). No sensorineural hearing loss was reported. Conclusions: The use of the CO2 laser fiber appears to be associated with slightly better hearing results than the KTP laser fiber, especially when assessed at the 4 kHz frequency.