Evaluation of Vascular Activity in Otosclerosis by Laser Doppler Flowmetry: Comparison With Computed Tomographic Densitometry

Objective To evaluate vascular activity in ears with otosclerosis by intraoperative measurement of blood flow using laser Doppler flowmetry and to compare the data with densitometry on computed tomography (CT). Design Retrospective case series. Setting University hospital. Patients Thirty-nine ears from 33 patients who underwent surgery for otosclerosis. Intervention The subjects were divided into fenestral (29 ears) and retrofenestral (10 ears) groups based on CT findings. Ratios of bone density in the area anterior to the oval window (AOW) or the promontory (PT) near the round window niche to that of the basis labyrinthine otic capsule were calculated on CT images. Measurements of blood flow were performed with a laser Doppler flowmeter at the 2 corresponding areas evaluated by CT. Main Outcome Measures Imaging and blood flow values. Results In both groups, relatively young subjects with high blood flow values in the AOW or PT had rather low ratios of bone density in the corresponding areas. In contrast, old subjects with low ratios of bone density showed low blood flow values in the same areas. In the retrofenestral group, subjects with high blood flow values in the PT showed low blood flow values in the AOW, but their ratios of bone density were similarly low in both areas. Conclusion Blood flow varied and did not correlate with CT densitometry. Measurement of blood flow by laser Doppler flowmetry could yield useful information to evaluate the progress of vascular activity.