High fluence in laser stapedotomy aggravates transient subjective dizziness

Laser fenestration in stapedotomy has thermal effect to the vestibule.

To evaluate the role of energy density (fluence) in the severity of postoperative vestibular symptoms.

The retrospective chart-review study included 84 patients with otosclerosis that underwent primary laser stapedotomy. Surgical outcomes, including nystagmus, and subjective vestibular symptoms during one-month follow-up, were compared between potassium titanyl phosphate (KTP) and CO₂ laser. According to this study and literature, we assessed the relationship between laser parameters and the incidence of persistent vestibular symptoms lasting more than one week after surgery.

The KTP and CO₂ laser group included 48 and 36 patients, respectively. Fluence was different between the KTP (637 J/cm²) and CO₂ (141 J/cm²) laser (p < .001). The KTP group showed gradual decrease in dizziness during one-month observation period, while the CO₂ group exhibited a steep recovery curve in the first postoperative week (9 and 4 d of duration, respectively). The incidence of persistent vestibular symptoms was correlated with both fluence (r = 0.80, p = .01) and spot size (r = -0.74, p = .01).

Appropriate setting of parameters with lower fluence is desirable for the efficiency and safety of laser stapedotomy.Abbreviations: ABG: air-bone gap; SD: standard deviation.