Hamid Borghei-Razavi

Collision Tumor of Meningioma and Malignant Astrocytoma

The authors report a 12-year-old boy who was presented with headache, nausea, vomiting and seizure. His magnetic resonance imaging showed 2 adjacent tumors in the region of the left ventricular trigone. The pathology of tumors reported collision tumors composed of meningioma and malignant astrocytoma.

Pathological Location of Cranial Nerves in Petroclival Lesions: How to Avoid Their Injury during Anterior Petrosal Approach

Objectives Numerous surgical approaches have been developed to access the petroclival region. The Kawase approach, through the middle fossa, is a well-described option for addressing cranial base lesions of the petroclival region. Our aim was to gather data about the variation of cranial nerve locations in diverse petroclival pathologies and clarify the most common pathologic variations confirmed during the anterior petrosal approach. Method A retrospective analysis was made of both videos and operative and histologic records of 40 petroclival tumors from January 2009 to September 2013 in which the Kawase approach was used. The anatomical variations of cranial nerves IV-VI related to the tumor were divided into several location categories: superior lateral (SL), inferior lateral (IL), superior medial (SM), inferior medial (IM), and encased (E). These data were then analyzed taking into consideration pathologic subgroups of meningioma, epidermoid, and schwannoma. Results In 41% of meningiomas, the trigeminal nerve is encased by the tumor. In 38% of the meningiomas, the trigeminal nerve is in the SL part of the tumor, and it is in 20% of the IL portion of the tumor. In 38% of the meningiomas, the trochlear nerve is encased by the tumor. The abducens nerve is not always visible (35%). The pathologic nerve pattern differs from that of meningiomas for epidermoid and trigeminal schwannomas. Conclusion The pattern of cranial nerves IV-VI is linked to the type of petroclival tumor. In a meningioma, tumor origin (cavernous, upper clival, tentorial, and petrous apex) is the most important predictor of the location of cranial nerves IV-VI. Classification of four subtypes of petroclival meningiomas using magnetic resonance imaging is very useful to predict the location of deviated cranial nerves IV-VI intraoperatively.

Anterior petrosal approach: The safety of Kawase triangle as an anatomical landmark for anterior petrosectomy in petroclival meningiomas

OBJECT Anterior petrosectomy through the middle fossa is a well-described option for addressing cranial base lesions of the petroclival region. To access posterior fossa through middle fossa, we quantitatively evaluate the safety of Kawase triangle as an anatomical landmark. METHOD We reviewed pre- and postoperative Multi-Slice CT scan (1mm thickness) of patients with petroclival meningioma between Jan 2009 and Sep 2013 in which anterior petrosectomy was performed to access the posterior fossa part of the tumor. The distances between drilling start and finish edge to the vital anatomical skull base structures such as internal auditory canal (IAC) and superior semicircular canal and petrous apex (petrous part of the carotid artery) were measured and analyzed. RESULTS Drilling entrance length is directly related with tumor size. The distances between anatomical structures and drilling points decrease with increasing tumor size, but it always remains a safe margin between drilling points and IAC, internal carotid artery (ICA), and semicircular canals in axial and coronal views. CONCLUSION The Kawase triangle is shown to be a safe anatomical landmark for anterior petrosectomy. The described landmarks avoid damage to the vital anatomical structures during access to the posterior fossa through middle fossa, despite temporal bone anatomical variations and different tumor sizes.

Isolated primary craniopharyngioma in the cerebellopontine angle

Between January 2000 and January 2011, we diagnosed three patients with isolated craniopharyngioma in the cerebellopontine angle (CPA). Brain MRI revealed cystic lesions with various imaging characteristics, including hypointensity on T1-weighted (T1W) images and hyperintensity on T2-weighted (T2W) images. The first patients lesion showed rim enhancement after gadolinium administration. The second patients lesion showed mixed signal intensity on both T1W and T2W images. The third patients MRI showed a well-defined cystic lesion in the right CPA that compressed the brainstem. This lesion was hyperintense on T1W images and hypointense relative to cerebrospinal fluid on T2W images, and was peripherally enhanced after gadolinium administration. All three patients underwent surgical intervention through a suboccipital retrosigmoid craniotomy/craniectomy and lesions that did not adhere to adjacent tissues were removed completely. Histopathological examination confirmed the tumors to be adamantinomatous craniopharyngioma. The post-operative course was uneventful for all patients uneventful and no tumor recurrences were detected at the last follow-up. Primary CPA craniopharyngioma can be completely removed surgically, provided it does not densely adhere to vital structures.

Intradiploic orbital roof meningioma with pneumosinus dilatans in a child: a case report and review of the literature.

Intradiploic meningioma of the orbital roof is a type of intraosseous meningioma. It is very rare in children, and only 7 cases have been reported in the pediatric age group. We report a case of a 14-year-old female who presented with progressive exophthalmos, diplopia and pain involving the right eye. Computed tomography (CT) scan and magnetic resonance imaging (MRI) revealed an intradiploic orbital roof tumor with diploe expansion and pneumosinus dilatans. The tumor was completely removed surgically. The histopathological diagnosis was transitional meningioma. The clinical and radiological findings of intadiploic meningioma are discussed with a review of the relevant literature.

Sacral dural arteriovenous fistula presented as an acute isolated thoracic myelopathy: Clinical and surgical importance

UNLABELLED We report a case of dural Arteriovenous Fistula (AVF) supplied by the lateral sacral artery that is located in the sacral region and presented as isolated thoracic myelopathy. METHOD AND RESULTS After S3 hemilaminectomy and opening the dura, the engorged arterialized vein has been interrupted. Postoperatively, the patients symptoms and myelopathy gradually resolved. CONCLUSION We are going to highlight the clinical and surgical importance of our case and discuss the pathophysiology of such an unusual clinical finding.

“Münster correlation” in temporal bone: surgical relevance of an anatomical study

Abstract Resection of the temporal bone to various degrees provides different levels of access to lesions of the posterior fossa. However, precise distances to the petrosal bone are still not clearly described. We evaluated the different distances of temporal bone landmarks in order to assess their variations and the possible correlations between them. We also evaluated the surgical relevance of the possible correlations. An anatomical study was performed on 60 temporal bones from 60 human cadavers. All bones contained an adequate portion of the petrous apex and attached fossa dura. We analyzed the variation in different distances between landmarks and also the correlations between different measured distances. There was a statistically significant correlation between the distance between the inferior axial plane of the posterior semicircular canal to the superior plane of jugular bulb and the thickness of the mastoid cortex at the M point (M point was defined by the authors). This correlation is important for estimating the height of the jugular bulb during a lateral suboccipital craniotomy in cerebellopontine angle surgery. The Münster correlation is an easy and safe method for estimating the height of the jugular bulb in cerebellopontine angle surgery.

Disabling Vertigo and Tinnitus Caused by Intrameatal Compression of the Anterior Inferior Cerebellar Artery on the Vestibulocochlear Nerve: A Case Report, Surgical Considerations, and Review of the Literature

Microvascular compression of the vestibulocochlear nerve is known as a cause of tinnitus and vertigo in the literature, but our review of the literature shows that the compression is usually located in the cerebellopontine angle and not intrameatal. We present a case of intrameatal compression of the anterior inferior cerebellar artery (AICA) on the vestibulocochlear nerve of a 40-year-old woman with symptoms of disabling vertigo and intermittent high-frequency tinnitus on the left side without any hearing loss for ∼ 4 years. Magnetic resonance imaging of the brain did not show any abnormality, but magnetic resonance angiography showed a left intrameatal AICA loop as a possible cause of the disabling symptoms. After the exclusion of other possible reasons for disabling vertigo, surgery was indicated. The intraoperative findings proved the radiologic findings. The large AICA loop was found extending into the internal auditory canal and compressing the vestibulocochlear nerve. The AICA loop was mobilized and separated from the vestibulocochlear nerve. The patients symptoms resolved immediately after surgery, and no symptoms were noted during 2 years of follow-up in our clinic. Her hearing was not affected by the surgery. In addition to other common reasons, such as acoustic neuroma, disabling vertigo and tinnitus can occur from an intrameatal arterial loop compression of the vestibulocochlear nerve and may be treated successfully by drilling the internal acoustic meatus and separating the arterial conflict from the vestibulocochlear nerve.

Multi-size, Multi-angle Microbipolar Forceps for Skull Base Surgery: Technical Note

Objective Hemorrhage control in skull base surgery is critical but hindered by the lack of instruments suitable for coagulating structural curves and corners. The main impediment is that most of the instruments currently used are right-angled and unsuitable because anatomical and pathologic structures are three-dimensional objects having complex curves and corners. In this article, we present a solution: the use of angled bipolar microforceps having a range of small diameters and angles for dissection and coagulation. Methods Utilizing modern design software and up-to-date synthetic and metallic materials, a variety of nonstick bipolar microforceps with different angles and very fine tips (0.2–1.2 mm) were designed and constructed for use on different anatomical and pathologic curves. The tips of the forceps were made very fine to improve coagulation precision as well as to improve microdissection dexterity. The blades were made long and thin to improve visibility during coagulation and dissection procedures. As a result, these multi-size, multiangle micro instruments can be used not only for coagulation but also for microdissection or tumor removal in most anatomical areas accessed during the course of skull base surgery Results The research, design, and construction of a new bipolar microforceps with different angles and sizes represents a technical innovation that can lead to improved surgical outcomes. Conclusion The new micro-instruments enhance the quality and quantity of tumor and tissue resection and dissection in skull base surgery and open the possibility of new surgical approaches to microscopic tumor resection and hemorrhage coagulation in the anatomical areas of the skull base.

Endoscopic anterior transmaxillary “transalisphenoid” approach to Meckel’s cave and the middle cranial fossa: an anatomical study and clinical application

OBJECTIVEMultiple approaches have been designed to reach the medial middle fossa (for lesions in Meckels cave, in particular), but an anterior approach through the greater wing of the sphenoid (transalisphenoid) has not been explored. In this study, the authors sought to assess the feasibility of and define the anatomical landmarks for an endoscopic anterior transmaxillary transalisphenoid (EATT) approach to Meckels cave and the middle cranial fossa.METHODSEndoscopic dissection was performed on 5 cadaver heads injected intravascularly with colored silicone bilaterally to develop the approach and define surgical landmarks. The authors then used this approach in 2 patients with tumors that involved Meckels cave and provide their illustrative clinical case reports.RESULTSThe EATT approach is divided into the following 4 stages: 1) entry into the maxillary sinus, 2) exposure of the greater wing of the sphenoid, 3) exposure of the medial middle fossa, and 4) exposure of Meckels cave and lateral wall of the cavernous sinus. The approach provided excellent surgical access to the anterior and lateral portions of Meckels cave and offered the possibility of expanding into the infratemporal fossa and lateral middle fossa and, in combination with an endonasal transpterygoid approach, accessing the anteromedial aspect of Meckels cave.CONCLUSIONSThe EATT approach to Meckels cave and the middle cranial fossa is technically feasible and confers certain advantages in specific clinical situations. The approach might complement current surgical approaches for lesions of Meckels cave and could be ideal for lesions that are lateral to the trigeminal ganglion in Meckels cave or extend from the maxillary sinus, infratemporal fossa, or pterygopalatine fossa into the middle cranial fossa, Meckels cave, and cavernous sinus, such as schwannomas, meningiomas, and sinonasal tumors and perineural spread of cutaneous malignancy.