Middle cranial fossa approach for acoustic neuroma

The middle fossa approach for the resection of small acoustic neuromas is a viable, but underutilized treatment modality with the goal of hearing preservation. The authors aim to demonstrate this approach and its nuances through this video presentation. A 38-year-old man presented with an incidentally discovered small, intracanalicular acoustic neuroma that was initially observed, but growth was noted. The patient had good hearing, and therefore a hearing preservation approach was offered. A gross-total resection was achieved, and the patient maintained good hearing postoperatively. This video demonstrates relevant anatomy, surgical indications, technical aspects of resection, including reconstruction, and postoperative outcomes. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID21124

Hearing preservation middle fossa approach for intracanalicular vestibular schwannoma in a NF2 patient

Hearing preservation is a cornerstone in the management of intracanalicular vestibular schwannomas. This video demonstrates a middle fossa approach to an intracanalicular schwannoma and highlights some technical and anatomical nuances relevant to the procedure. The patient had sustained hearing preservation in the postoperative period. There are potential benefits in favor of the middle fossa when the tumor reaches the fundus of the internal auditory canal, but the surgeon’s individual experience plays a decisive role in the choice of approach. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID21121

Resection of a Dumbbell-Shaped Facial Nerve Schwannoma With Preservation of Facial Nerve Function Through the Extended Middle Fossa Approach: 2-Dimensional Operative Video

Facial nerve schwannomas are rare and can arise from any segment along the course of the facial nerve.1 Their location and growth patterns present as distinct groups that warrant specific surgical management and approaches.2 The management challenge arises when the facial nerve maintains good function (House-Brackmann grade I-II).3 Hence, a prime goal of management is to maintain good facial animation. In large tumors, however, resection with facial nerve function preservation should be sought and is achievable.4,5 While tumors originating from the geniculate ganglion grow extradural on the floor of the middle fossa, they may extend via an isthmus through the internal auditory canal to the cerebellopontine angle forming a dumbbell-shaped tumor. Despite the large size, they may present with good facial nerve function. These tumors may be resected through an extended middle fossa approach with preservation of facial and vestibulocochlear nerve function. The patient is a 62-yr-old man who presented with mixed sensorineural and conductive hearing loss and normal facial nerve function. Magnetic resonance imaging (MRI) revealed a large tumor involving the middle fossa, internal auditory meatus, and cerebellopontine angle. The tumor was resected through an extended middle fossa approach with a zygomatic osteotomy and anterior petrosectomy.6 A small residual was left at the geniculate ganglion to preserve facial function. The patient did well with hearing preservation and intact facial nerve function. He consented to the procedure and publication of images. Image at 1:30 © Ossama Al-Mefty, used with permission. Images at 2:03 reprinted from Kadri and Al-Mefty,6 with permission from JNSPG.

Extended Middle Fossa Approach for Trigeminal Schwannoma Resection

Trigeminal schwannomas are rare benign tumors, it is second most common intracranial schwannomas after vestibular schwannomas. The management includes not limited to observation, stereotactic radiosurgery/radiotherapy, and/or surgical resection. Tumor size and patient clinical status are the most important factors in management.In this video, we describe the technical nuances of an extended middle fossa approach for large trigeminal schwannoma with cavernous sinus extension resection. A 44-year-old right-handed female with several months' history of progressive right facial paresthesia and pain in the distribution of V3 mainly. On physical examination, she had decreased sensation to light touch over the right V1 to V3 distribution with loss of cornel reflex. The brain MRI showed 3.5 cm bilobed mass extends from the pontine root entry zone to the cavernous sinus. Craniotomy was performed and followed by middle fossa dural peeling, peeling of temporal lobe dura away from the wall of the cavernous sinus, extradurally anterior clinoidectomy, drilling of the petrous apex, coagulation of superior petrosal sinus followed incision of the tentorium up to the tentorial notch with preservation the fourth cranial nerve, and tumor dissected away from V1 and then gradually removed from the superior wall of the cavernous sinus.The technique presented here allows for complete tumor resection, safe navigation through the relative cavernous sinus compartments, and minimizes the possibility of inadvertent injury to the cranial nerves.The postoperative course was uneventful except for right eye incomplete ptosis from the swelling. Her facial pain subsided after the surgery without any extra ocular movement impairment.The link to the video can be found at: https://youtu.be/zxi2XK2R9QU.

Extirpation of Recurrent Petrous Apex Cholesterol Granuloma Through the Zygomatic Approach: 2-Dimensional Operative Video

Petrous apex cholesterol granulomas are believed to result from blockage of the normal aeration of the petrous air cells, resulting in a repetitive cycle of mucosal engorgement, hemorrhage, and granuloma formation.1 The lesion usually progressively expands causing compressive symptoms. The thick granulomatous wall envelopes various ages of breakdown products, including a cholesterol-containing fluid, which is typically hyperintense on T1 and T2 weighted magnetic resonance imaging. Drainage procedures, regardless of the route (endoscopic, endonasal, or transtemporal), with or without stenting or marsupialization, will only temporarily drain this cholesterol-containing fluid, with consequently frequent recurrences.2-5 A total exoneration of the granuloma and obliteration of the cavity with vascularized tissue will assure a more durable outcome.1 The extradural zygomatic/middle fossa approach provides a short distance to the petrous apex and is purely extradural. By sectioning the zygoma, temporal lobe retraction is avoided.6 We present a case of a 29-yr-old male who presented in the year 2000 with progression of a left petrous apex cholesterol granuloma despite 2 previous drainage and stenting procedures. The patient consented for surgery and photo publication. Images in video at 2:41 © JNSPG, republished from Eisenberg et al1 with permission.

Gross Total Resection of a Recurrent Cavernous Sinus Meningioma through a Combined Transzygomatic Transcavernous and Extended Middle Fossa Approach with Cavernous Carotid Denudation

Objective The aim of this study is to describe surgical management of invasive cavernous sinus meningioma with a combination of skull base approaches. Design This study is an operative video. Results Resection of the recurrent skull base meningioma is still challenging, especially if the tumor involves or encases the carotid artery. In this video, we describe our experience with the successful treatment of a recurrent skull base meningioma, which involved the entire cavernous sinus and the internal carotid artery. A 53-year-old male presented with a 1-year history of progressing right-side complete oculomotor palsy and facial dysesthesia. The patient had previously undergone craniotomy for the right-side petroclival cavernous meningioma (Fig. 1A and B). Total 8 years after the first surgery, the remaining portion of the cavernous sinus grew up and extended into the posterior fossa (Fig. 1C). Then the second surgery was performed to resect only the posterior fossa component (Fig. 1D). However, the follow-up magnetic resonance imaging revealed an aggressive tumor regrowth in 2 years. The tumor occupied the right middle fossa with an extension to the posterior fossa and infratemporal fossa (Fig. 1E and F). We scheduled to perform gross total resection of the tumor through a combined transzygomatic transcavernous and extended middle fossa approach with preparation for vessel reconstruction. Mild adhesion between the tumor and the cavernous carotid artery facilitated complete resection of the intracavernous component of the tumor (Fig. 2A–C). Conclusion A combination of skull base approaches provides multidirectional operative corridors and wide exposure of the skull base lesions.The link to the video can be found at https://youtu.be/DB_WXFeyBvo.

Venous Anatomy Influence on the Approach Selection of a Petroclival Clear Cell Meningioma With Associated Multiple Spinal Meningiomas: 2-Dimensional Operative Video

Preoperative careful evaluation of the sigmoid transverse sinus and its tributary veins is paramount for the safe surgical planning of petroclival lesions.1,2 When the vein of Labbé is running within the tentorium, classic petrosal approach involving transection of the tentorium is modified to avoid the risk of postoperative morbid temporal lobe venous infarcts.1-3 Thus, the surgical plan should be tailored to the specific patient anatomy as demonstrated in the presented case during which a transmastoid approach was followed, in the same surgical setting, by a middle fossa approach to resect a large petroclival clear cell meningioma with extension into Meckel cave. These meningiomas are WHO grade II tumors with a propensity to local recurrence and cerebrospinal fluid seeding.4 SMARCE1 mutations define this subtype of meningioma, with frequent familial inheritance, and predispose patients to both skull base and spinal clear cell meningiomas.5,6 Maximal surgical resection is the best initial treatment option allowing to withhold or delay the use of radiation in tumors frequently encountered in young patients.7 In this report, we demonstrate the microsurgical techniques deployed to achieve maximal resection of a petroclival clear cell meningioma and associated lumbar and sacral spinal meningiomas in a 20-yr-old patient with a familial SMARCE1 mutation. The patient agreed to the surgical intervention and to the use of her image.

Cervicofacial surgery and implantable hearing device extrusion: management of challenging cases

ObjectiveTo describe our management of implantable hearing device extrusion in cases of previous cervicofacial surgery.MethodsA review was conducted of a retrospectively acquired database of surgical procedures for implantable hearing devices performed at our department between January 2011 and December 2019. Cases of device extrusion and previous cervicofacial surgery are included. Medical and surgical management is discussed.ResultsFour cases of implant extrusion following cervicofacial surgery were identified: one involving a Bonebridge system and three involving cochlear implants. In all cases, antibiotic treatment was administered and surgical debridement performed. The same Bonebridge system was implanted in the middle fossa. The three cochlear implants were removed, and new devices were implanted in a more posterior region.ConclusionPrevious cervicofacial surgery is a risk factor for hearing implant extrusion. The middle fossa approach is the best option for the Bonebridge system. Regarding the cochlear implant, it is always suitable to place it in a more posterior area. An inferiorly based fascio-muscular flap may be a good option to reduce the risk of extrusion.