Analysis of hearing preservation after endolymphatic mastoid sac surgery for Meniere's disease.

OBJECTIVES/HYPOTHESIS: Comparison of audiometric outcomes between patients with definite Meniere's disease who underwent endolymphatic mastoid sac surgery (EMSS) following failed medical therapy and patients who underwent medical therapy only. STUDY DESIGN: Retrospective chart review of 456 consecutive patients between 1997 and 2006. METHODS: Outcome measures were changes in pure-tone average (PTA), word recognition score (WRS), and speech reception threshold (SRT). RESULTS: Of 58 qualified patients, 29 who underwent EMSS after failing medical therapy showed a 4 dB decrease in PTA, a 2% increase in WRS, and a 2 dB decrease in SRT. Twenty-nine patients treated with medical therapy only demonstrated a 1 dB PTA increase, 2% WRS improvement, and 2 dB SRT improvement. No significant difference was noted between the medically and surgically managed patients in terms of changes in PTA (P = .34) or WRS (P = .95) after treatment. Of all patients in the study, 60% had no clinically significant change in hearing, whereas 24% improved and 16% worsened. The distribution of post-treatment hearing changes between the medical and surgical groups was statistically insignificant (P = .17). CONCLUSIONS: The changes in PTA and WRS among patients with Meniere's disease managed with medical therapy or EMSS were not statistically significant. Although performing EMSS to treat the vertigo of Meniere's disease does not appear to be associated with an increased risk of deteriorating auditory function after treatment, surgery also does not confer an increased likelihood of stabilizing or improving hearing.

Ewing's Sarcoma of the Petrous Temporal Bone: Case Report and Literature Review.

Ewing's sarcoma, which accounts for 6 to 9% of malignant bone neoplasms in children, typically affects the trunk and long bones and less often affects the skull (i.e., maxilla, frontal, parietal, ethmoid, temporal bones). Adding to literature of five previously reported cases, we now describe the case of the oldest child, a 16-year-old boy, with a primary Ewing's sarcoma of the petrous temporal bone. When this patient presented after 1 week of right-sided facial paralysis and new-onset headache, imaging studies showed a mass that originated in the right petrous temporal bone. During biopsy and surgical excision, the mass was found to involve the facial nerve, which then required nerve grafting. Postoperatively, he then underwent radiotherapy with both induction and adjuvant chemotherapy. Although an uncommon tumor of the temporal bone, physicians should consider Ewing's sarcoma in the differential diagnosis of children and adolescents who present with facial nerve paralysis.

Delayed extrusion of hydroxyapatite cement after transpetrosal reconstruction.

OBJECTIVE: Use of hydroxyapatite cement has been advocated for closure of transpetrosal defects to decrease the incidence of cerebrospinal fluid leaks. We previously identified delayed extrusion of this cement as a significant complication associated with this closure technique and now update our long-term experience. METHODS: In our retrospective review, we identified 1231 patients who underwent transpetrosal procedures by our multidisciplinary cranial base team between 1984 and 2005. Of the subgroup of 177 patients who had hydroxyapatite cement used during the closure of the procedure, 13 patients (7.3%) experienced delayed extrusion of hydroxyapatite cement. RESULTS: Extrusion occurred in 3 patients within 12 months and in 10 patients within 68 to 140 months. Twelve patients presented with draining fistulae and concomitant Staphylococcus aureus infection; 1 patient presented asymptomatically with a large temporal lobe abscess identified on surveillance magnetic resonance imaging. All 13 patients underwent reoperation, including 1 who underwent a second procedure. CONCLUSION: Delayed extrusion of hydroxyapatite cement resulted in significant morbidity to our patients and often presented in an indolent manner. We recommend serial examination and imaging studies in patients who have had transpetrosal closures with hydroxyapatite cement. Because of the complication rates associated with hydroxyapatite cement, we have discontinued its use.

Petrous carotid canal dehiscence: an anatomic and radiographic study.

HYPOTHESIS: Development of the osseous petrous carotid canal is frequently incomplete. BACKGROUND: Although dehiscence of the carotid canal has been observed in previous studies, the frequency and extent of bony dehiscence have not been quantified. Inadvertent internal carotid artery injury occurs in 3 to 5% of skull base procedures, with an additional 1.9% of patients having carotid artery vasospasm. Documentation of the incidence of petrous apex carotid canal dehiscence is therefore warranted. METHODS: Ninety-nine cadaveric skulls were evaluated physically and by computed tomographic scan. RESULTS: Incidence of dorsal (endocranial) dehiscence of the petrous carotid canal was identified in 82.83% of the left side and 88.89% of the right side. Average dimensions for left dorsal dehiscence measured 10.81 mm longitudinally by 4.10 mm transversely. Dimensions for the right averaged 11.59 mm longitudinally by 4.29 mm transversely. Incidence of ventral (exocranial) dehiscence was less frequent: 37.37% on the left and 34.34% on the right. Ventral dehiscence was classified into major (absence of bone) and minor (fissure) types. Major dehiscence was observed in 8.08% and 6.06% of specimens for left and right sides, respectively; minor ventral dehiscence was present in 29.29% and 28.28% for left and right sides, respectively. CONCLUSION: Dorsal petrous carotid canal dehiscence is more common than previously recognized. Dehiscence of the dorsal carotid canal is a frequent finding with significant implications in advanced skull base approaches to the petrous apex, clivus, and lateral sellar compartment. Ventral dehiscence is a frequent finding that will become increasingly relevant as the scope of endoscopic skull base procedures.