Partial Clipping Occlusion Including Rupture Point Is an Effective Strategy for Ruptured Giant Fusiform Basilar Artery Aneurysm: A Technical Case Report

Treatment of fusiform basilar artery aneurysms is still challenging today. The authors present a case of a patient with a ruptured giant fusiform basilar artery aneurysm successfully treated by clipping occlusion of the rupture point. A 62-year-old man suddenly fell into a coma due to subarachnoid hemorrhage (SAH) with a ruptured giant fusiform basilar artery aneurysm with a bleb on the right shoulder. We considered treating the lesion with stent-assisted coil embolization because of the aneurysm's shape, but we had to give up because stents were off-label in the acute phase SAH in our country. Instead, we successfully performed clipping surgery to partially occlude the aneurysm, including the rupture point via the anterior transpetrosal approach. His postoperative course was uneventful, without rerupture of the aneurysm, and his conscious level tended to improve. The postoperative imaging studies showed no complications and disappearance of the rupture point of the aneurysm. Although direct surgery for the giant fusiform basilar artery aneurysms is one of the challenging operations, it is an essential and highly effective treatment as a last resort for complex aneurysms if other treatments are not available.

Anterior transpetrosal approach: experiences in 274 cases over 33 years. Technical variations, operated patients, and approach-related complications

OBJECTIVE The anterior transpetrosal approach (ATPA) was initially reported in 1985. The authors’ institution has 274 case records of surgery performed with the ATPA during the period from 1984 to 2017. Although many technical advances and modifications in the ATPA have occurred over those 33 years, to the authors’ knowledge no articles to date have reported a detailed analysis of variations and complications of the ATPA. In this study, the authors analyzed their patient series to elucidate improvements over time in ATPA methodology while highlighting unresolved problems and evaluating how to avoid surgical complications. METHODS All surgical cases (274 patients) using the ATPA at the authors’ institution during the period from 1984 to 2017 were analyzed retrospectively using charts, clinical summaries, operative records, and operative videos. Obtained parameters were patient age and sex, diagnosis, size of tumors, location of disease, operative date, neurological symptoms before and after surgery, radiographically identified brain injury, and other surgical complications. The most common diagnosis was petroclival meningioma (n = 158), followed by trigeminal schwannoma (n = 32), chordoma (n = 25), epidermoid tumor (n = 21), other tumor (n = 27), aneurysm (n = 6), and other (n = 5). RESULTS The original ATPA was performed in 239 cases. In an additional 35 cases, a modified ATPA was performed. Zygomatic osteotomy with ATPA was a common modification that was used in 19 of the 35 cases to decrease retraction damage to the temporal lobe for high-positioned tumors. Brain injury by temporal lobe retraction without venous hemorrhage still occurred in 8 of the 19 cases (3.1%) with surgical death in 1 of these cases (0.4%) of reoperation with sacrifice of the petrosal vein. Symptomatic CSF leak was the most frequent complication noted and was observed in 35 cases (13.5%). In most of these cases the patients were cured by observation or lumbar drain, but in 6 cases (17.1%) reoperation was needed. Facial nerve damage related to surgical approach decreased from 6.2% to 3.5% after 2010; however, the incidence of CSF leaks (13.5%) has not improved. CONCLUSIONS There have been several modifications and advancements made in the ATPA to increase tumor removal and decrease surgical complications. However, complications related to surgical approach occurred, such as venous occlusion–related brain injury and facial nerve damage at pyramid resection. CSF leak remained an unsolved problem related to the ATPA procedures. Preoperative assessment of venous variation of the middle fossa, pneumatization of the temporal bone, and intraoperative monitoring of cranial nerves are important procedures to decrease these complications.

Anterior transpetrosal resection of the lower ventral pontine cavernous malformation: A technical case report with operative video

Background: Surgical treatment of pontine cavernous malformations (CMs) is challenging due to the anatomical difficulties and potential risks involved. We successfully applied an anterior transpetrosal approach (ATPA) to remove a lower ventral pontine CM, and herein we discuss the outline of our procedure accompanied by a surgical video. Case Description: A 50-year-old woman presenting with progressively worsening diplopia was urgently admitted to our hospital. Preoperative images showed a lower ventral pontine CM compressing the corticospinal tract posteriorly. Considering the location of the CM, we determined that an ATPA was the appropriate approach to achieve a more anterolateral trajectory. We performed extradural anteromedial petrosectomy and penetrated the brainstem from the point just below the anterior inferior cerebellar artery and above the root exit zone of the abducens nerve, which might be located in the somewhat lowest border of actual maneuverability in the ATPA. Maneuverability through this corridor was sufficient without hindering and darkening the high magnification microscopic view, as demonstrated in our surgical video. Conclusion: This report demonstrates surgical treatment of a lower ventral pontine CM using the ATPA. The surgical video we present provides information that is useful for understanding this technique’s maneuverability and working window.

Resection of Pontine Cavernoma Through the Anterior Transpetrosal Approach

The pons is the most frequent local for brain stem cavernoma.1 Repeated hemorrhage of brainstem cavernoma is associated with significant and accumulative neurological deficits and thus requires treatment. According to the Swedish Karolinska’s group of radiosurgery, ”it could not be concluded whether GKRS affects the natural course of a CM. The incidence of radiation-induced complications was approximately seven times higher than that expected.”2 Thus, microsurgical removal has become the mainstay of treatment. In our experience, the following details assist in obtaining favorable outcomes and avoiding postoperative complications3,4: (a) the entry into the cavernoma based on thorough knowledge of the microanatomy; (b) the detailed study of the images and the presentation of the cavernoma on or near the brain stem surface; (c) the resection of the live cavernous hemangioma and not the mere removal of the multiple aged organized hematomas; (d) the preservation of the associated venous angioma; (e) the direct and shortest access to the lesion provided by a skull base approach; and (f) the use of the available technology, such as intraoperative neuromonitoring and neuroimaging. We present the case of a 54-yr-old male with recent deterioration in year 2001, past repetitive episodes of gait imbalance, and speech difficulty over a 7-yr period from known pontine cavernoma. The anterior petrosal approach provided superb and direct exposure to the entry at the lateral pons and the cavernoma was totally removed with preservation of the venous angioma. His preoperative neurological deficit rapidly recovered. Patient consented to the procedure and photography. Images at 3:15 from Kadri et al, The anatomical basis for surgical presercation of temporal muscle. J Neurosurg. 2004;100:517-522, used with permission from JNSPG. Image at 3:27 from Al-Mefty O, Operative Atlas of Meningiomas, © LWW, 1997, with permission.

Use of Neuroanatomic Knowledge and Neuronavigation System for a Safe Anterior Petrosectomy

Introduction: The petroclival region is among the most challenging anatomical areas to deal with in skull base surgery. Drilling of the anterior part of the petrous bone during the anterior transpetrosal approach involves the risk of injury of the cochlea, superior semicircular canal, internal carotid artery, and internal auditory canal. A thorough understanding of the microneurosurgical anatomy of this region is mandatory to execute the transpetrosal approaches, decreasing the risk of complications. The aim of this study is to describe the anatomical structures of the petroclival region, highlighting the importance of neuronavigation for safe performance of the anterior transpetrosal approach. Methods: Three adult cadaveric human heads were formalin-fixed and injected with colored silicone. They underwent an axial 1 mm slab CT scan, which was used for neuronavigation during the surgical approaches. The anterior petrosectomy was performed with the aid of neuronavigation during the drilling of the petrous bone. The surgical management of a patient harboring a petroclival meningioma, operated on using an anterior transpetrosal approach, was reported as an illustrative case. Results: The anterior petrosectomy was completed accurately with wide exposure of the surgical target without injuring the cochlea and other structures in all three cadaveric specimens. In the surgical case, no approach-related complications occurred, and a gross total resection of the tumor was achieved. Conclusions: Deep knowledge of the location and relationships of the vital elements located within the temporal bone, along with the use of neuronavigation, are the key aspects to perform the anterior transpetrosal approach safely, reducing the risk of complications.

Endoscope-assisted microsurgical repair in trigeminal meningocele: case report

Trigeminal meningocele is a rare disease that results in rhinorrhea. Treatments with endoscopic approaches and open craniotomies have high recurrence rates, and controversy regarding the most effective surgical strategy for trigeminal meningocele is ongoing. The authors report a case of a 13-year-old female patient with a diagnosis of trigeminal meningocele determined after she presented with a history of intermittent headaches, suspected rhinorrhea, and recurrent meningitis. In addition to the conventional method of covering the efflux point of CSF and filling the inside of the meningocele with fascial tissues, the authors selectively closed the influx point of CSF from the prepontine cistern to the meningocele using an anterior transpetrosal approach. On the basis of the preoperative images, the authors hypothesized that the influx point of CSF could not be observed under the microscopic direct view and instead used a flexible endoscope. A check valve–like structure with one-way communication of CSF from the prepontine cistern into the cystic cavity was identified and was closed. At the time of this report, 36 months postoperatively, the patient had no indications of recurrence. Although cases of trigeminal meningoceles are infrequently encountered and require a tailored approach, the results in this case thus far indicate that the use of an endoscope and open craniotomy is an effective strategy for surgical treatment.

Anterior Transpetrosal Approach and Microsurgical Resection of a Petrous Tentorial Meningioma: 3-Dimensional Operative Video

Tentorial meningiomas are challenging tumors because of its complex relationship with vital neurovascular structures. We present the case of a 41-yr-old female with a history of right-sided facial numbness associated with pain around the ear. Magnetic resonance imaging demonstrated a lesion in the right tentorium edge closely related with the porus trigeminus, suggestive of a meningioma. Because of worsening of symptoms the patient underwent surgery for tumor removal. A standard temporo-zygomatic craniotomy was performed, followed by an extradural peeling of the middle fossa; the petrous apex was drilled allowing access to the posterior fossa dura. Dural opening was carried connecting the temporal and posterior fossa, and the tentorium was then cut to the incisura. The tumor was identified and completely removed reaching Simpson grade I resection. Postoperatively, the patient presented a right dry eye in the first days that fully improved, and also a right-sided facial paralysis (House-Brackmann grade IV) and diplopia, both recovered completely after 4 mo. We believe that facial paralysis was the result of an undesired traction of the geniculate ganglion, or upon the nerve itself. To avoid such complication, dissection over the GSPN must be carried parallel to that nerve. Facial numbness and pain improved with no neurological other deficits. Tentorial meningiomas are complex deep-seated lesions that can be successfully approached through an anterior transpetrosal route in selected cases. Informed consent was obtained from the patient for publication of this operative video. Anatomical images were a courtesy of the Rhoton Collection, American Association of Neurological Surgeons/Neurosurgical Research and Education Foundation.