Transsylvian Approach Research Articles

Single fronto-temporal sylvian vein reconstruction when treating a large partially thrombosed aneurysm of the M1 middle cerebral artery

<p>The article describes a clinical case of clipping the neck of large partially thrombosed aneurysm by using a transsylvian approach. A feature of the case is an atypical structure of the Sylvian fissure, with just one vein draining both the frontal and the temporal lobes and hindering access to the Sylvian fissure. The problem was solved by cutting the vein, performing the aneurysm neck clipping and suturing the cut vein by means of end-to-end technique. </p><p>Received 19 April 2016. Accepted 7 September 2016.</p><p><strong>Funding:</strong> The study had no sponsorship.<br /><strong>Conflict of interest:</strong> The authors declare no conflict of interest.</p>

The transsylvian approach for resection of insular gliomas: technical nuances of splitting the Sylvian fissure.

Insular gliomas represent a unique surgical challenge due to the complex anatomy and nearby vascular elements associated within the Sylvian fissure. For certain tumors, the transsylvian approach provides an effective technique for achieving maximal safe resection. The goal of this manuscript and video are to present and discuss the surgical nuances and appropriate application of splitting the Sylvian fissure. Our hope is that this video highlights the safety and efficacy of the transsylvian approach for appropriately selected insular gliomas.

Vision after trans-sylvian or temporobasal selective amygdalohippocampectomy: a prospective randomised trial.

Selective amygdalohippocampectomy (SAH) is an accepted surgical procedure for treatment of pharmacoresistant mesial temporal lobe epilepsy, but it may lead to postoperative visual field deficits (VFDs). Here we present a prospective randomised trial comparing the postoperative VFDs after either a trans-sylvian or temporobasal approach for SAH. Forty-eight patients were randomly assigned to trans-sylvian (n = 24) or temporobasal (n = 24) SAH. Postoperative VFD were quantitatively evaluated using automated static and kinetic perimetry. In 24 cases, diffusion tensor imaging-based deterministic fibre-tracking of the optic radiation was performed. The primary endpoint was absence of postoperative VFD. The secondary endpoint was seizure outcome and driving ability. Three patients (13%) from the trans-sylvian group showed no VFD, compared to 11 patients (46%) from the temporobasal group without VFD (p = 0.01, RR = 3.7; CI = 1.2-11.5). Fifteen patients from each group (63%) became completely seizure-free (ILAE1). Among those seizure-free cases, five trans-sylvian (33%) and ten temporobasal (66%) patients could apply for a driving licence (NNT = 3) when VFDs were considered. Although the trans-sylvian group experienced more frequent VFDs, the mean functional visual impairment showed a tendency to be less pronounced compared with the temporobasal group. DTI-based tracking of the optic radiation revealed that a lower distance of optic radiation to the temporal base correlated with increased rate of VFD in the temporobasal group. Temporobasal SAH shows significantly fewer VFDs and equal seizure-free rate compared with the trans-sylvian SAH. However, in patients in whom the optic radiation is close to the temporal base, the trans-sylvian approach may be a preferred alternative.

Orbital gyrusの形態に着目した開放しにくいsylvian fissureの術前評価と手術における留意点

Background: The deep-lying cisternal part of the Sylvian fissure stem is structurally complex. A more developed posterior orbital gyrus (pOG) adds complexities to the dissection in that plane because adhesion between the pOG and the temporal lobe is much thicker and stronger in such cases. The purpose of this study was to suggest a method of preoperative estimation of the degree of development of the pOG by using only axial-view computed tomographic (CT) images.Methods: First, we retrospectively classified 32 patients who underwent clipping of the anterior circulation aneurysms via the transsylvian approach at our institution into three types as follows, according to the degree of difficulty of the Sylvian fissure stem dissection evaluated using operative videos: type A, difficult; type B, normal; and type C, easy. Second, we hypothesized that an imaginary line (line D) joining the medial point of the Sylvian fissure with the limen insulae on axial CT images corresponds to the posterior rim of the pOG. Then, we evaluated the characteristics of line D in each case.Results: Five cases were type A, and line D was curved with a backward convexity, with a mean length of 4 cm. Eleven cases were type B, and line D was curved with a backward convexity, with a mean length of 3.5 cm. Sixteen cases were type C, and line D was curvilinear or straight, with a mean length of 3.48 cm.Conclusion: Preoperative evaluation of the morphological feature of the pOG is useful in estimating the degree of difficulty of Sylvian fissure stem dissection via the transsylvian approach.

Chronic Encapsulated Expanding Thalamic Hematoma Associated with Obstructive Hydrocephalus following Radiosurgery for a Cerebral Arteriovenous Malformation: A Case Report and Literature Review.

Chronic encapsulated intracerebral hematoma is a unique type of intracerebral hematoma accompanied by a capsule that is abundant in fragile microvasculature occasionally causing delayed regrowth. A 37-year-old man who had undergone radiosurgery for an arteriovenous malformation (AVM) causing intracerebral hematoma in the left parietal lobe presented with headache, vomiting, and progressive truncal ataxia due to a cystic lesion that had been noted in the left thalamus, leading to progressive obstructive hydrocephalus. He underwent left frontal craniotomy via a transsylvian fissure approach, and the serous hematoma was aspirated. The hematoma capsule was easy to drain and was partially removed. Pathological findings demonstrated angiomatous fibroblastic granulation tissue with extensive macrophage invasion. The concentration of vascular endothelial growth factor (VEGF) was high in the hematoma (12012 pg/mL). The etiology and pathogenesis of encapsulated hematoma are unclear, but the gross appearance and pathological findings are similar to those of chronic subdural hematoma. Based on the high concentration of VEGF in the hematoma, expansion of the encapsulated hematoma might have been caused by the promotion of vascular permeability of newly formed microvasculature in the capsule.

Radical resection of a craniopharyngioma via the extradural anterior temporal approach with zygomatic arch osteotomy.

Background:Though the extradural anterior temporal approach (EDATA) with zygomatic osteotomy is useful, there are only few reports of this approach being used for craniopharyngioma resection. Herein, we report our surgical case series and the technical importance of EDATA for the radical removal of a craniopharyngioma.Methods:We report 7 cases of craniopharyngiomas treated surgically between April 1999 and October 2015. The surgical approaches, clinical presentation, pre and postoperative radiographic examination results, surgical outcomes, and morbidity were analyzed.Results:The mean follow-up period was 89.1 months. The surgical approach was EDATA with zygomatic osteotomy in 4, combined interhemispheric translamina terminalis approach (IHTLA) and trans-sylvian anterior temporal approach (ATA) in 2, and IHTLA in 1 patient. Complete tumor resection was achieved in all cases, without any recurrence during the follow-up period. Transient morbidities were oculomotor nerve palsy in 2, and meningitis and hydrocephalus in 1 patient. There was 1 case of permanent morbidity due to hydrocephalus that needed a ventriculoperitoneal shunt, and 1 case of blindness on the operative side. Visual acuity and visual field improved in 4 cases, showed no change in 2 cases, and deteriorated in 1 case. Though the pituitary stalk was preserved in 2 cases, all 7 cases needed total hormone replacement therapy.Conclusion:EDATA with zygomatic osteotomy ensures sufficient mobility of the internal carotid artery, and provides a good lateral and look up operative view. Hence, it can be used effectively for radical resection of craniopharyngiomas through the opticocarotid space and retrocarotid space.

Indocyanine Green (ICG) Videoangiography-Guided Dissection of the Sylvian Fissure on the Transsylvian Approach: Technical Note

The transsylvian approach is a standard method of approach for anterior circulation aneurysms or paraclinoid tumors. Care must be taken, however, to avoid inadvertent obliteration of sylvian veins to prevent postoperative brain swelling and venous infarction. Sometimes, the superficial sylvian veins have complex connections or are not visible because of the thickness of the arachnoid membrane, especially in the case of subarachnoid hemorrhage (SAH). The present report describes a simple method to dynamically visualize the sylvian vein via indocyanine green (ICG) angiography for the purposes of appropriately wide dissection of the sylvian fissure. Before dissection of the sylvian fissure and after opening the dura mater, a bolus of ICG is administered intravenously. ICG videoangiography is used for dynamic venography at 10 seconds after the depiction of branches of the middle cerebral artery. Clear documentation of the sylvian vein was obtained via ICG videoangiography, even in cases of SAH with ambiguous anatomical topography attributable to clot under the superficial arachnoid membrane. ICG was able to differentiate between the sylvian veins of the frontal and temporal lobes, which allowed wide dissection of the sylvian fissure while preserving the veins. ICG videoangiography is an easy and useful method for identifying the connections and tributaries of the superficial sylvian veins from a transsylvian approach. This method allows wide opening of the sylvian fissure while preserving the sylvian veins.

Cerebral blood flow reactivity in patients undergoing selective amygdalohippocampectomy for epilepsy of mesial temporal origin. A prospective randomized comparison of the trans-Sylvian and the transcortical approach

Objective: The aim of this study was to assess (1) whether vasoreactivity is altered in patients with epilepsy and (2) whether the two most commonly used approaches, the trans-Sylvian (TS) and the trans-cortical (TC) route, differ in their impact on cortical blood flow.Methods: Patients were randomized to undergo selective amygdalohippocampectomy (selAH) through a TC or TS route. Before and after selAH, we recorded microcirculation parameters on the superficial cortex surrounding the surgical corridor. Blood flow and velocity were measured using laser Doppler flowmetry and micro-Doppler, respectively. Cortical oxygen saturation (SO2) was measured using remission spectrophotometry under hypocapnic and normocapnic conditions.Results: Ten patients were operated using the TS approach, and eight were operated via the TC approach. Vasomotor reactivity patterns measured with micro-Doppler were physiologically prior to selAH in both groups. After completion of surgery, a significant increase in SO2-values occurred in the TS group (before: 56.7 ± 2.2, after: 65.5 ± 3.0%SO2), but not in the TC group (before: 52.9 ± 5.2, after: 53.0 ± 3.7%SO2). The rate of critical SO2 values below 25% was significantly higher after the TC approach (12.3%) compared to the TS approach (5.2%; p < 0.05).Discussion: Our findings provide the first invasively measured evidence that patients with mesial temporal lobe epilepsy have preserved cerebral blood flow responses to alterations in CO2. In addition, local cortical SO2 was higher in the TS group than in the TC group after selAH. This may be a sign of reactive cortical vessel dilation after proximal vessel manipulation associated with the TS approach. In contrast, the lower values of SO2 after the TC approach indicate tissue ischaemia surrounding the surgical corridor surrounding the corticotomy.

Intraoperative nursing cooperation for micro-surgical clipping of middle cerebral artery aneurysms

Objective To investigate the importance of nursing cooperation in the operation of middle cerebral artery aneurysm (MCAA) microsurgical clipping. Methods We retrospectively analyzed 202 cases (male 103 cases, female 99 cases) of MCAA patients who were underwent microsurgical clipping surgery (from January 1997 to December 2013), and the importance of nursing cooperation in the process were analyzed. A total of 242 aneurysms were found during surgery of 212 cases underwent craniotomy clipping, in which 215 cases were MCAA, and 2 cases underwent autologous dura wrapping, except one unbroken MCAA case was embolism. Results All patients in this group underwent Yasargil′s pterional trans-sylvian approach, 212 MCAA surgery were successfully clipped. 174 cases were clipped without rupture (81.3%), while rupture (18.7%) occurred in 40 patients during surgery. All patients had been treated with controlled hypotension and intracranial hypotension, through timely blood transfusion, infusion and other response measures to ensure the successful completion of surgery. Conclusions It can help will the operation completed smoothly and improve surgical effects by personalized utilizing of controlled hypotension, brain tissue relaxation techniques and other measures in microsurgical clipping of MCAA, as well as good nursing cooperation during the process of aneurysms rupture. Key words: Middle cerebral artery aneurysms; Microsurgical clipping; Intraoperative nursing

Surgical assessment of the insula. Part 1: surgical anatomy and morphometric analysis of the transsylvian and transcortical approaches to the insula.

Transcortical and transsylvian corridors have been previously described as the main surgical approaches to the insula, but there is insufficient evidence to support one approach versus the other. The authors performed a cadaveric comparative study regarding insular exposure, surgical window and freedom, between the transcortical and transsylvian approaches (with and without cutting superficial sylvian bridging veins). Surgical anatomy and skull surface reference points to the different insular regions are also described. Sixteen cadaveric specimens were embalmed with a customized formula to enhance neurosurgical simulation. Two different blocks were defined in the study: first, transsylvian without (TS) and with the superficial sylvian bridging veins cut (TSVC) and transcortical (TC) approaches to the insula were simulated in all (16) specimens. Insular surface exposure, surgical window and surgical freedom were calculated for each procedure and related to the Berger-Sanai insular glioma classification (Zones I-IV) in 10 specimens. Second, the venous drainage pattern and anatomical landmarks considered critical for surgical planning were studied in all specimens. In the insular Zone I (anterior-superior), the TC approach provided the best insular exposure compared with both TS and TSVC. The surgical window obtained with the TC approach was also larger than that obtained with the TS. The TC approach provided 137% more surgical freedom than the TS approach. Only the TC corridor provided complete insular exposure. In Zone II (posterior-superior), results depended on the degree of opercular resection. Without resection of the precentral gyrus in the operculum, insula exposure, surgical windows and surgical freedom were equivalent. If the opercular cortex was resected, the insula exposure and surgical freedom obtained through the TC approach was greater to that of the other groups. In Zone III (posterior-inferior), the TC approach provided better surgical exposure than the TS, yet similar to the TSVC. The TC approach provided the best insular exposure, surgical window, and surgical freedom if components of Heschl's gyrus were resected. In Zone IV (anterior-inferior), the TC corridor provided better exposure than both the TS and the TSVC. The surgical window was equivalent. Surgical freedom provided by the TC was greater than the TS approach. This zone was completely exposed only with the TC approach. A dominant anterior venous drainage was found in 87% of the specimens. In this group, 50% of the specimens had good alternative venous drainage. The sylvian fissure corresponded to the superior segment of the squamosal suture in 14 of 16 specimens. The foramen of Monro was 1.9 cm anterior and 4.42 cm superior to the external acoustic meatus. The M2 branch over the central sulcus of the insula became the precentral M4 (rolandic) artery in all specimens. Overall, the TC approach to the insula provided better insula exposure and surgical freedom compared with the TS and the TSVC. Cortical and subcortical mapping is critical during the TC approach to the posterior zones (II and III), as the facial motor and somatosensory functions (Zone II) and language areas (Zone III) may be involved. The evidence provided in this study may help the neurosurgeon when approaching insular gliomas to achieve a greater extent of tumor resection via an optimal exposure.

Microsurgical treatment of the insular lobe gliomas

Objective To investigate the preoperative evaluation methods and intraoperative measures of the extent of resection and blood vessel protection in insular glioma resection surgery via transsylvian approach. Methods The clinical data in 46 patients with glioma mainly in insular lobe treated by surgery at the Department of Neurosurgery, Brain Hospital Affiliated to Nanjing Medical University from January 2008 to July 2014 were analyzed retrospectively. M2 was exposed after separating lateral fissure via the pterion or extended pterional approach. After processing the short perforator from M2, the gliomas were resected piecemeal. The outermost artery of internal capsule did not participate in the insular lobe glioma blood supply, and it was the inner side border for glioma resection. Results Under the microscope, the gliomas of 38 patients were resected near totally and were confirmed by the postoperative imaging. The gliomas of 8 patients were resected subtotally, 2 had hemiplegia after procedure, and one had subdural hemorrhage. After procedure, 3 patients had contralateral limb hemiparesis (strength grade IV). One had a transient mixed aphasia. Conclusions Preoperative imaging findings, especially 3D-TOF of the relationship in between the gilomas and vessels, have an important guiding role for intraoperative blood vessel protection. The outermost artery of internal capsule is the medial boundary of giloma resection. Key words: Giloma; Microsurgery; Blood vessels; Insular lobe

Microsurgical anatomy of the inferior limiting insular sulcus and the temporal stem.

The purpose of this study was to describe the location of each white matter pathway in the area between the inferior limiting insular sulcus (ILS) and temporal horn that may be crossed in approaches through the temporal stem to the medial temporal lobe. The fiber tracts in 14 adult cadaveric cerebral hemispheres were examined using the Klingler technique. The fiber dissections were completed in a stepwise manner, identifying each white matter pathway in different planes and describing its position in relation to the anterior end of the ILS. The short-association fibers from the extreme capsule, which continue toward the operculae, are the most superficial subcortical layer deep to the ILS. The external capsule fibers are found deeper at an intermediate layer and are formed by the uncinate fasciculus, inferior frontooccipital fasciculus, and claustrocortical fibers in a sequential anteroposterior disposition. The anterior commissure forms the next deeper layer, and the optic radiations in the sublenticular part of the internal capsule represent the deepest layer. The uncinate fasciculus is found deep to the anterior third of the ILS, whereas the inferior frontooccipital fasciculus and optic radiations are found superficial and deep, respectively, at the posterior two-thirds of this length. The authors' findings suggest that in the transsylvian approach, a 6-mm incision beginning just posterior to the limen insula through the ILS will cross the uncinate fasciculus but not the inferior frontooccipital fasciculus or optic radiations, but that longer incisions carry a risk to language and visual functions.

Surgical anatomy of the insular cortex

The objective of the study was to investigate the surgical anatomy of the insular cortex, morphology and vascularization of the insula and adjacent opercula in terms of transsylvian and transcortical approaches, and identification of the permissible anatomical boundaries for resection of glial tumors of the insula. The study was conducted on 18 anatomical specimens fixed in an alcohol-glycerol solution. Perfusion of the internal carotid artery with red latex was used to study the arterial system. Dissection of the arteries and Sylvian fissure, investigation of the morphological features of the opercula as well as simulation of the transsylvian and transcortical approaches to the insula were performed using a surgical microscope, in a certain sequence. In the trassylvian approach, the anteroinferior part of the insula (including the limen insulae) is the most technically easy-to-reach area, whereas the superior parts of the insula are the most difficult-to-reach areas. With the tumor localized in the superior insula, the transcortical approach may be recommended that, unlike the transsylvian approach, does not require a significant retraction of the brain matter and provides a larger surgical corridor. The transcortical approach, regardless the insular region, provides a better surgical view and workspace compared to the transsylvian approach. However, the previous approach is characterized by less access to the important anatomical landmarks such as the peri-insular sulci, limen insulae, and lateral lenticulostriate arteries. Furthermore, the approach requires dissection of the brain matter of the frontal and temporal lobes. Detailed knowledge of the surgical anatomy of the insular region provides correct intraoperative identification of a number of the major anatomical landmarks (limen insulae, peri-insular sulci, most distal lenticulostriate artery) and facilitates choosing the proper surgical approach.

Superficial temporal artery to proximal posterior cerebral artery bypass through the anterior temporal approach.

Background:The superficial temporal artery (STA) to proximal posterior cerebral artery (PCA) (P2 segment) bypass is one of the most difficult procedures to perform because the proximal PCA is located deep and high within the ambient cistern. STA to proximal PCA bypass is usually performed through a subtemporal approach or posterior transpetrosal approach, and rarely through a transsylvian approach. The aim of this study was to describe the operative technique of STA to proximal PCA bypass through a modified transsylvian approach (anterior temporal approach).Methods:STA to proximal PCA bypass was performed through an anterior temporal approach in three patients with intracranial aneurysm. We describe the details of the surgical technique.Results:The STA was successfully anastomosed to the proximal PCA in all cases. One patient suffered hemiparesis and aphasia due to infarction in the anterior thalamoperforating artery territory.Conclusions:STA to proximal PCA bypass can be performed through an anterior temporal approach in selected patients. We recommend that every precaution, including complete hemostasis, placement of cellulose sponges beneath the recipient artery to elevate the site of the anastomosis, and placement of a continuous drainage tube at the bottom of the operative field to avoid blood contamination during the anastomosis, should be taken to shorten the temporary occlusion time.

Keyhole Transsylvian Resection of Infiltrative Insular Gliomas: Technique and Anatomic Results.

Insular gliomas have traditionally been approached through variations of large frontotemporal craniotomies exposing much of the Sylvian fissure. Due to the importance of many structures exposed by such an approach, a less-invasive approach to these lesions is a viable alternative for resection. We present the technique and results of our keyhole transsylvian approach to remove infiltrating insular tumors. A small linear incision and keyhole craniotomy is planned under image guidance to open a transsylvian window. Using a combination of the microscope and endoscope, we remove the insula circumferentially outward. We present our results of 20 patients with gliomas confined to the insula evaluated with volumetric imaging analysis. There were 12 right-sided and 8 left-sided tumors. The median skin-to-skin operative time was 215 minutes. 15/20 patients were discharged from the hospital on or before post-operative day 3, with 5 of those going home the day after surgery. Greater than 90% of the tumor was removed in 18 of 20 cases, with an additional case achieving 89.5% resection. In no case was the residual tumor volume greater than 3 cc. Permanent weakness occurred in 2 patients (10%). Despite a significant number of left-sided tumors, temporary dysphasia occurred in only 1 patient (12.5%), which resolved by first follow up. Localized insular gliomas can be effectively removed through a minimally invasive approach without increasing the risk of neurological morbidity. This minimizes manipulation of uninvolved, potentially eloquent cortices, and minimizes damage to the overlying soft tissue.

Surgical resection of insular cavernomas with a transsylvian approach

Objective To explore the surgical strategy for insular cavernous malformations (CMs).Methods Between Dec.2007 and Aug.2013,4 patients with insular CMs were treated surgically through transsylvian approach by using image guidance system (neuronavigation in two cases,ultrasound in four cases).Results The seizure was the initial symptom in 4 patients with insular CMs.The image guidance system provided high-quality intraoperative imaging and guided the perfect operative approach of insular cortex dissection.All CMs were completely removed via transsylvian-transinsular approach.The mean follow-up period was 36.75 months (ranged from 3 to 72 months).Permanent neurologic morbidity after surgery was observed in 1 patient.One patient with dominant hemisphere lesion had temporary dysphonia,and the language function was recovered after 1 week.4 patients were Engel class Ⅰ.Conclusions Surgical resection of insular CMs through transsylvian approach was safe.Neuronavigation and intraoperative ultrasound were recommended,especially for patients whose lesion was located in the dominant hemisphere. Key words: Cavernous malformation; Insula; Transsylvian approach; Neuronavigation; Intraoperative ultrasound

Anatomical study of insula and its relationship with the adjacent structures.

Insular lobe is folded deep in the sylvian fissure, and the transsylvian transinsular approach is one of the most commonly used methods for lesions in the insula, basal ganglia, amygdala, and hippocampus. Hence, it is essential for surgeons to master a specific anatomic knowledge of the insula and its adjacent structures. This study aims to locate the insula, measure relevant parameters, and reduce the occurrence of surgical injury and postoperative complications. One hundred three individuals (53 males and 50 females) were selected randomly, and magnetic resonance imaging-based morphometric analysis was performed. We located the landmark and measured the parameters related to the transsylvian transinsular approach. The parameters and figures in the sagittal, coronal, and axial planes were used to illustrate the anatomical relationship between the insular lobe and its adjacent structures. The length of the superior limiting sulcus (line A) was 52.05 ± 3.30 mm in the left and 51.56 ± 2.90 mm in the right. The length of the inferior limiting sulcus (line B) was 48.18 ± 3.01 mm in the left and 48.40 ± 3.34 mm in the right. The length of the anterior limiting sulcus (line C) was 22.64 ± 1.47 mm in the left and 22.50 ± 1.57 mm in the right. The length of the central insular sulcus (line D) was 31.36 ± 2.68 mm in the left and 31.52 ± 2.53 mm in the right. The distance from insular apex to brain surface through sylvian fissure (line E) was 19.26 ± 2.21 mm in the left and 19.36 ± 2.26 in the right. The distance from inferior limiting sulcus to the roof of temporal horn (line J) was 9.75 ± 1.38 mm in the left and 9.66 ± 1.18 mm in the right. The angle (θ), which was formed by line J and the vertical line via the inferior limiting sulcus (line I), was 30.51 ± 3.60 degrees in the left and 30.56 ± 3.11 degrees in the right. The distance from insular apex to the lateral side of putamen (line L) was 10.10 ± 1.59 mm in the left and 10.62 ± 1.39 mm in the right. The distance from insular apex to the middle of genu capsulae internae (line K) was 25.73 ± 1.02 mm in the left and 26.50 ± 1.15 mm in the right. Independent-samples t test showed no significant difference of the means between the right side and the left side. The statistics in our study can help to understand the complicated anatomical structures of insula and its surrounding area. Moreover, the parameters can increase the feasibility and safety of the surgery via transsylvian transinsular approach.

Yasargil Higway in Neurosurgery (For the nineteen years old of my teacher Mahmut Gazi YASARGIL)

My Teacher Professor Yasargil is very famous doctor, mentor, surgeon, lider, scientist, researcher, inventor and teacher of last Century, not only in Neurosurgery, but also in Neuroscience of the World. His very important Neurosurgical Way and thecniques, the pterional trans Sylvian approach, I called as “Yasargil Higway” is commonly employed in surgery of the anterior circulation and upper basilar artery aneurysms, as well as for the tumors of orbital, retroorbital, sellar, chiasmatic, sub frontal and prepontine areas and lesions around the sella especially for lesions behind the clivus. Also tumors arising from the medial sphenoid ridge, the superior orbital fissure, the anteromedial temporal surface, or the cavernous sinus region are approached through a pterional exposure. The modification of surgical technique is based on the experience, training and observation of the neurosurgeon. One technique is not necessarily better than the another. Regardless of the surgical technique, the end results depend on a rigorous, methodical, systematic, and step by-step approach to the target, securing it with minimal injury to surrounding structures.

Vascular events after transsylvian selective amygdalohippocampectomy and impact on epilepsy outcome

Epilepsy surgery is a standard treatment option for medically intractable temporal lobe epilepsy. Selective amygdalohippocampectomy (SAH) and anterior temporal lobectomy (ATL) are two of the standard surgical procedures in these cases. We conducted a retrospective analysis of patients treated with SAH via a modified transsylvian approach in our epilepsy center between 2008 and 2011, and we analyzed the impact of adjacent procedure-related infarctions on seizure outcome in these patients. Infarctions were detected by magnetic resonance imaging (MRI) within the first week postoperatively and by a second MRI 9 months after surgical intervention. Neuropsychological testing was performed preoperatively. Evaluation of seizure outcome and postoperative neuropsychological testing were conducted approximately 1 year after epilepsy surgery. Correlative clinical data were analyzed by retrospective chart review. The postoperative MRI revealed temporal infarctions in 47.9% (n = 23/48) and frontal infarctions in 10.4% (n = 5/48) of the patients. These vascular events were asymptomatic in terms of focal neurologic deficits. Of the patients, 68.5% (n = 37/54) were free of disabling seizures (Engel class I) 1 year after the procedure. Patients with temporal infarctions were significantly more often free of disabling seizures (Engel class I, p = 0.046) than patients without temporal infarctions. Neuropsychological testing indicated a deterioration in verbal memory after SAH in patients with infarctions on the language-lateralized hemisphere compared to patients without infarction (p = 0.011). All other tested neuropsychological categories showed no significant differences between patients with or without infarctions. Our results indicate a surprisingly high number of procedure-related temporal infarctions after transsylvian SAH. Hence, the volume of nonfunctional "eliminated" tissue is enlarged unintentionally, which is a possible explanation for better seizure outcome in these patients. This result supports the notion that ATL is the favorable procedure for temporal lobe epilepsy compared to SAH in the nondominant hemisphere, as neuropsychological deficits are rarely to be expected.

How I do it – selective amygdalohippocampectomy via subtemporal approach

Surgery is superior over medicamentous treatment of pharmacoresistant mesial temporal lobe epilepsy caused by hippocampal sclerosis. The armamentarium of surgical procedures comprises standard temporal lobectomy and more selective procedures. Selective amygdalohippocampectomy can be performed via transcortical, transsylvian or subtemporal approach. Describe the selective amygdalohippocampectomy through the subtemporal approach After the detailed preoperative epilepsy evaluation, surgery can be offered to pharmacoresistant epilepsy patient with hippocampal sclerosis. Selective amygdalohippocampectomy can be safely performed through the subtemporal approach. The good knowledge of the mesial temporal lobe anatomy is necessary when performing this procedure.