All audiological data is based on what was estimated at the first fitting of the audio processor. Radiological http://www.selleckchem.com/products/Imatinib-Mesylate.html scanning by flat-panel angiography was performed after May 2009. In the prospective portion of the study, 17 operations (between May 2009 and February 2010) were included using a standardized surgical approach. This approach consisted of the following steps.The RW was visualized by removing the promontory lip. Low-speed drilling away from the promontory lip was performed at 1000r/sec. Ivalon (a PVA sponge) was placed between the FMT and the round window. The FMT was stabilized at the distal end with cartilage and covered with fascia. This construction was covered with fibrin glue. Because they were fitted with the new Amade audio processor (AP), patients number 20 to 24 were only evaluated radiologically.

2.3. Radiological ExaminationDetermination of the FMT-RW position was performed with an Allura Xper FD20 system (Philips Medical Systems, Best, Netherlands), using a flat panel detector. The system’s parameters were as follows: entrance field of 22cm, 274mAs, 95kV, 180�� rotation, 241 projections, and filter 0.90mm Cu + 1.00mm Al and postero-anterior (p.a.). The focus panel distance was constant during the whole rotation at a frequency of 30pic/s. The 3D angiography was performed in the unsubtracted mode. From this volume data set, the temporal bones were secondarily enlarged (FoV of 100mm), digitally stored, and sent to an external workstation (Extended Brilliance Workspace, Philips, Cleveland, USA) for the 2D- and 3D-reconstruction.

The actual classification of the single scans was performed independently by two ENT surgeons and one radiologist. Since a correlation between the radiologic classification and the functional gain could not be observed (Figure 9), a secondary measurement was performed. Additional factors were introduced (AF, APR), which might represent the amount of gain reserve of the system after reaching the obtained functional gain. The assumption was that the more effort the system has to make to reach that FG for an audiological sufficient threshold (in case of insufficient coupling of the FMT to the RW membrane), the less APR remains, and therefore a smaller AF in comparison to a good coupling of the FMT persists.Figure 9Mean functional gain (overclosure) in dB.2.4.

Calculation of the ��Audio Processor Factor�� (AF) The AF should serve as an indicator for the quality of RW coupling. Two major determinants were considered, that is, the functional gain (calculated as warble tone threshold at the patients preferred volume settings minus postoperative bone conduction threshold) and the so-called audio AV-951 processor reserve. For a better visualization of the functional gain, the value is multiplied by ?1. The audio processor reserve was measured after the fitting by using an audio processor Type 404 (AP 404) in Kuppler mode (with a 2ccm chamber at 65dB).