Are Hounsfield Unit Measurements of Bony Absorption Changes in Cholesteatoma Helpful?

Introduction High-resolution computed tomography (HRCT) scans of the temporal bone are used to assess the bony erosion of the middle-ear structures whenever cholesteatoma is suspected. Objective To study the differences in HRCT Hounsfield unit (HU) index measurements of middle-ear bony structures between an ears with and without cholesteatoma. Methods A retrospective study of 59 patients who underwent surgery due to unilateral cholesteatoma. The HRCT HU index of the scutum, of three middle-ear ossicles, of the lateral semicircular canal (LSCC), and of the fallopian canal was measured in both ears. A comparison was made between the cholesteatoma and the non-cholesteatomatous ear (control). All measurements were conducted by an otolaryngologist. To assess the interobserver bias, 10% of the samples were randomly and independently assessed by another otolaryngologist and a neuroradiologist who were blinded. Results The average HU index was lower in the ear with cholesteatoma when compared with the non-cholesteatomatous ear. While the differences were statistically significant regarding the measurements of the scutum (516.02 ± 311.693 versus 855.64 ± 389.999; p = 0.001), the malleus (1049.44 ± 481.765 versus 1413.47 ± 313.376; p = 0.01), and the incus (498.03 ± 264.184 versus 714.25 ± 405.631; p = 0.001), the differences in the measurements of the LSCC (1042.34 ± 301.066 versus 1154.53 ± 359.609; p = 0.69) and of the fallopian canal (467.19 ± 221.556 versus 543.51 ± 263.573; p = 0.108) were not significantly different between both groups. The stapes was immeasurable in both groups due to its small size. Conclusion Hounsfield unit index measurements are a useful tool that may aid in the diagnosis of early-stage cholesteatoma.

Total Petrosectomy for the Total Resection of Sphenopetroclival Meningioma: 2-Dimensional Operative Video

Sphenopetroclival meningioma is a most formidable meningioma. Many patients have few preoperative deficits and surgery has the potential of severe neurological complications. Surgical treatment is challenging due to brainstem compression, the involvement of multiple cranial nerves and cerebral vessels. Wide tumor exposure, multiple dissection axis, and short distance are paramount factors in the quest of achieving total removal of Simpson grade I, including the involved dura and bone. The posterior petrosal, transtentorial presigmoid approach offers a wide and shallow operative field.1-7 When the patient has hearing loss, extending the resection of the temporal bone provides unmatchable exposure facilitating safer and more complete tumor removal. This article demonstrates the removal of a sphenopetroclival meningioma through total petrosectomy with closing of the external auditory canal and preservation of the facial nerve in the Fallopian canal. A total resection of the tumor was achieved with long-term preservation of cranial nerve function. The surgical steps of total petrosectomy are shown, including the skin flap, combined middle and posterior fossa craniotomy, skeletonization of the sigmoid transverse sinus, radical mastoidectomy, dissection of the Fallopian canal, and drilling of the labyrinth, cochlea, and petrous apex for superb exposure.8 We demonstrate the intra-arachnoidal microsurgical dissection utilized for the radical resection of petroclival meningioma. This surgery performed in 1995 is a testament to the time-tested technique. The patient consented to the procedure and image use. Images at 1:33 and 3:57 © Ossama Al-Mefty, used with permission.

A Giant Congenital Mastoid Cholesteatoma With Extension to the Occipital Condyle

A congenital mastoid cholesteatoma (CMC) is a keratinizing epithelium originating from embryological epithelial tissue of the mastoid. It is often not diagnosed until it becomes large because of its rarity and indolent nature. Although there are a few reports on giant CMC, its exact extensions have not been well described, and detailed information regarding surgical methods is lacking, especially in giant CMC involving the occipital condyle and the middle and posterior cranial fossae. In this article, we report a case involving a 70-year-old woman with a giant CMC that extended inferiorly to the occipital condyle. The CMC eroded the middle and posterior cranial fossae, sigmoid sinus plate, and fallopian canal of the facial nerve. For complete removal, we used a subtotal petrosectomy in conjunction with an exposure of the cranial cervical junction and a wide decompression of the suboccipit. The boundaries of exposure were similar to those of a petro-occipital transsigmoid approach which is usually used for management of tumor involving the jugular foramen. The wide exposure allowed for complete removal of the lesion without any complications. Thus, we recommend this surgical approach for management of the giant CMC involving the occipital condyle and the middle and posterior cranial fossae.