Removal of hydroxyapatite cement from cadaveric temporal bones after transtemporal surgery

Hypothesis: To determine the best method of removing hydroxyapatite cement from the temporal bone in the postoperative period. Background: The advent of hydroxyapatite cement in neurotologic surgery of the temporal bone has dramatically decreased the rate of postoperative cerebrospinal fluid leaks. However, there is no literature currently available on how to manage these patients in the setting of postoperative hematomas of the cerebellopontine angle. Methods: Nine cadaveric temporal bones were obtained that had previously undergone translabyrinthine approach drilling in an academic temporal bone lab. Fascia and adipose tissue were placed medial to the facial nerve and the temporal bone was then filled with hydroxyapatite cement to the level of the cortex. Removal of hydroxyapatite cement was undertaken using a Freer elevator, mastoid bone curette, and finally, a drill in sequential fashion. This occurred at 9 predetermined time intervals from 1 to 30 hours and was timed in each case. Results: Removal using the freer and curette failed in each case, and the drill was ultimately used to remove the hydroxyapatite cement in all cases. The time to reach the packed fascia and adipose tissue varied from 3 to 6 minutes, average time is 4.27 ± 0.84 minutes. Conclusion: Although hydroxyapatite cement has dramatically decreased the rate of postoperative cerebrospinal fluid leak in translabyrinthine surgery, its use has also brought a new set of considerations. This study suggests that hydroxyapatite cement removal in the setting of postoperative hematoma after translabyrinthine surgery would require drilling rather than bedside incisional opening alone. Like standard craniotomy approaches, postoperative hemorrhage management requires intraoperative drainage.