Medial Acoustic Tumors: Special Considerations: 2-Dimensional Operative Video

Medial acoustic tumors are a rare distinct type of vestibular schwannoma having distinguished clinical and radiological features.1 Originating medially in the cerebellopontine angle without extending into the lateral internal auditory meatus, they are frequently giant in size at presentation in younger patients with a relatively preserved hearing, while they have other neurological deficits from cerebellar or brainstem compression and associated hydrocephalus. Imaging typically shows a cystic tumor with local mass effect and an internal auditory canal filled with cerebrospinal fluid.1,2 Surgical resection of theses schwannoma is particularly challenging not only due to their size and hypervascularity, but also given their particular arachnoidal rearrangement inducing marked adherence to the brainstem and facial nerve.2 The treatment is surgical resection, despite, however, their giant size hearing preservation should be sought and is attainable.1–5 Transmastoid approach with squeletonization and reflection of the transverse sigmoid sinus provides lateral exposure avoiding cerebellar retraction.6 In this report, we demonstrate the specific surgical considerations applied to the resection of a giant medial acoustic tumor in a 40-yr-old patient presenting with ataxia, vertigo, facial paresthesia, and intact hearing. The patient agreed to the surgery and photography. Image at 1:44 © Ossama Al-Mefty, used with permission; Image at 8:21 from Dunn et al,2 used with permission from JNSPG.

Translabyrinthine resection of small intracanalicular acoustic tumor

This case is an example of a translabyrinthine resection of a small intracanalicular acoustic tumor. The patient is a 69-year-old right-handed woman with complaints of progressive incapacitating vertigo and right-sided hearing loss worsening over the past 3 years. She had normal facial nerve function with imaging demonstrating progressive increase in size of a small right-sided acoustic tumor. A translabyrinthine approach was performed, and the mass was resected completely. Facial nerve function remained normal immediately after surgery.The video can be found here: http://youtu.be/27ARlLLSbKE.

Anesthesia Dolorosa of Trigeminal Nerve, a Rare Complication of Acoustic Neuroma Surgery

Anesthesia dolorosa is an uncommon deafferentation pain that can occur after traumatic or surgical injury to the trigeminal nerve. This creates spontaneous pain signals without nociceptive stimuli. Compression of the trigeminal nerve due to acoustic neuromas or other structures near the cerebellopontine angle (CPA) can cause trigeminal neuralgia, but the occurrence of anesthesia dolorosa subsequent to acoustic tumor removal has not been described in the medical literature. We report two cases of acoustic neuroma surgery presented with anesthesia dolorosa along the trigeminal nerve distribution. The patients’ pain was managed with multidisciplinary approaches with moderate success.

Retromastoid-sub occipital: A novel approach to cerebello pontine angle in acoustic neuroma surgery-our experience in 21 cases

ABSTRACT Background: Acoustic neuroma surgery poses significant challenges regarding definite management and preservation of hearing and the facial nerve are of great concern. Aim: To analyze the efficacy of the retromastoid approach in acoustic neuroma surgery. Materials and Methods: Tumors operated between January 2002 and December 2008, by the authors, using the retromastoid approach, were analyzed. Twenty-one patients who presented with acoustic tumor were considered for this study. Discussion: Precise knowledge of the neuroanatomy in the cerebellopontine angle is the key to success and microsurgical technique is the sole factor for good outcome. Conclusion: Retromastoid, in fact is the approach to the skull base with minimal or no damage to neurovascular structures, in contrast to the translabyrinthine or presigmoid approach.