Transsylvian Approach Research Articles

Surgical Techniques and Prevention of Complications in the Treatment of Basal Ganglia Hemorrhage Through the Distal Transsylvian Approach.

Basal ganglia hemorrhage can damage the internal capsule and lead to high rates of disability and mortality. The distal transsylvian approach is a validated approach in the treatment of basal ganglia hemorrhage. However, this approach is difficult and prone to complications. The present study was performed to investigate the surgical techniques and prevention of complications of basal ganglia hemorrhage through the distal transsylvian approach. From January 2015 to January 2018, the authors treated 40 cases of basal ganglia hemorrhage using the distal transsylvian approach. The surgical video recordings and the patients' clinical data were retrospectively analyzed. The authors discussed the surgical techniques and prevention of complications through the distal transsylvian approach. Thirty-eight cases of basal ganglia hemorrhage were successfully treated through the distal transsylvian approach. The other 2 cases were converted to the transcortical transtemporal approach. In the early cases, complications occurred in 3 stages: sylvian fissure dissection, insula lobectomy, and hematoma removal. In the subsequent cases, the authors implemented appropriate surgical techniques to prevent complications. Basal ganglia hemorrhage can be treated through the distal transsylvian approach, but not in all patients. The distal transsylvian approach is highly technical and more problematic than the transcortical transtemporal approach. Mastering certain operative skills can reduce the surgical complications.

Microsurgical Approach to Hypertensive Deep Nuclear Bleed: Preliminary Experience and Short Term Outcome

Efficacy of surgical evacuation of hypertensive deep nuclear bleed with or without decompressivecraniectomy remains controversial. Our paper mainly focuses on short-term preliminary experience on the evacuation of hypertensive deep nuclear bleed via transsylvian approach in reducing secondary brain injury for better neurological outcome. In between August 2012 to October 2013, 25surgically managed patients with hypertensive deep nuclear bleed were reviewed retrospectively. Among them, 13 cases underwent transsylvianevacuation of hematoma.84.6% were males. Age ranged between 38 to68 years with a mean age of 50.23 with standard deviation of 8.29 years. The size of hematoma measured in computed tomography scan ranged from 48 to 156 ml (mean 69 ml with standard deviation 38.28 ml). Nine hypertensive patients were taking medication on an irregular basis. The remaining had never taken antihypertensive agents before the ictus. 7/15 was the lowest Glasgow Coma Scale score and 13/15 was the highest score on arrival to the emergency room. Eight cases showed near-total evacuation of hematoma on repeated scan was taken after24 hours of surgery. One patient underwent transsylvian evacuation in 2nd postoperative day after recollection following the trans frontale vacation of right putaminal bleed. Two patients died on 3rd and 4th post-operative day respectively (GOS=1). GOS score during discharge was 3 in three cases and five cases obtained score 4. Three cases obtained GOS 5.In a 3-month clinical follow-up, one case scored modified Rankin Scale 1, three cases scored 2, four cases obtained score 3, two others scored modified Rankin Scale grade 4 and one case had modified Rankin Scale 6.Transsylvian transinsular microsurgical technique safely depicts the anatomical orientation in sylvian fissure preserving the overlying eloquent cortex in frontal and temporal lobes. This aided us to achieve better surgical and neurological outcome in patients with hypertensive deep nuclear hemorrhage irrespective to the size of hematoma.

Portable 3D-Head Computed Tomography (CT) Navigation-Guided Key-Hole Microsurgery for Spontaneous Hypertensive Hemorrhages

BackgroundThis case series study evaluated the outcome and effect of portable 3D-head computed tomography (CT, MCT-I, 16 rows mobile CT made in China) navigation-guided key-hole microsurgery for supratentorial hypertensive hematomas.Material/MethodsThirty-five consecutive unconscious patients with a significant volume of hypertensive intracranial hemorrhages (HICH) were treated with 3D image-guided key-hole microsurgery, and the clinical features were summarized. Preoperative and postoperative hematoma volumes and reduction in midline shifts were calculated and recorded. The preoperative and postoperative (initial, discharge, and 180th day after stroke onset) neurological status was assessed by Glasgow Outcome Scale (GOS), Glasgow Coma Scale (GCS), and modified Rankin Scale (mRS) score, respectively.ResultsThe range of hematoma volumes of surgical patients was 24–99 ml (median, 50 ml). The median time of CT scan (from the time of the request to navigation finish) was 11 min. Total and near-total (>90%) hematoma evacuation was achieved in 96.9% cases. Compared with the initial state of neurological assessment, there was a significant improvement in MRS and GCS at discharge (P<0.001). After 6 months, 57.1% of patients had achieved functional recovery (GOS 4–5) and 2 patients had died.ConclusionsAs a minimally invasive technique, image-guided transcortical sulci or transsylvian approach is highly effective for immediate and complete hematoma evacuation.

Can sectioning the posterior communicating artery be predicted with computed tomography angiography in the microsurgical clipping of basilar apex aneurysms?

Microsurgical clipping is a viable option for managing high-riding basilar apex aneurysms (BAXs) using a transsylvian approach. Cutting the posterior communicating artery (PCoA) at the perforator-free zone provides sufficient exposure of BAX, although it is not always safe. The aim was to qualitatively predict sectioning of the interfering PCoA by using preoperative computed tomographic angiography (CTA). A virtual trajectory from the lesser sphenoid wing to the neck of the aneurysm was simulated on CTA in 19 consecutive patients operated on BAX aneurysms from 2013 to 2018. The angles on CTA resembled the typical view through the extended pterional craniotomy. Next, the ipsilateral PCoA was tracked from the internal carotid to its end at the posterior cerebral artery in the trajectory. The opticocarotid and carotid-oculomotor window served as the corridors for entering the interpeduncular fossa in 16 patients (84.2%) and in 3 patients (15.8%), respectively. The PCoA was intentionally cut during nine surgeries and preserved in 10 of them. The PCoA was cut more often when positioned toward the cranial base and more medially in the corridor; both the Kernel density analysis and the data points representing the position of the PCoA supported this finding (p < 0.01). The CTA-based position of either ends of the PCoA in the trajectory did not differ between cut and not-cut groups (p = 0.19-0.96). Aneurysm projection, rupture, size, PCoA diameter, length, and other distances on CTA were not related to the sectioning of PCoA (p > 0.05). The probability of PCoA sectioning is higher when the PCoA is positioned medially and closer to the cranial base. If the anatomical course of the PCoA is recognized beforehand, it can contraindicate surgery. Preoperative CTA-based planning facilitates the surgery of BAX aneurysms. Therefore, CTA can make microsurgical clipping planning more predictable for the neurosurgeon and safer for the patient.

Incidental Microaneurysms During Microvascular Surgery: Incidence, Treatment, and Significance

Although new imaging tools have been developed for the detection of smaller aneurysms, angiographically negative microaneurysms are still encountered during cerebral microsurgery. Currently, only limited information regarding incidence and efficacy of treatment of these microaneurysms is available. We investigated the incidence and treatment of incidental microaneurysms (IMAs) in the last 5 years. IMAs are unidentifiable and invisible on preoperative angiography, but are detected during microvascular surgery. The inclusion criteria were aneurysm cases treated with microsurgery via transsylvian approaches, and those undergoing preoperative digital subtraction angiography. This study enrolled 484 surgical cases (248 cases of subarachnoid hemorrhage and 236 cases of unruptured aneurysms) in 460 patients, and 33 tiny aneurysms were found in 31 operative cases (6.4% incidence per operation). The most typical type was located on another branching site of the middle cerebral artery found during neck clipping of the middle cerebral artery bifurcation aneurysm. A patient with multiple aneurysms presented a statistically significant risk (375/78 vs. 15/16; P < 0.001) of IMA identification. IMAs were treated by clipping and wrapping in 18 and 15 cases, respectively, without complications. This study revealed a 6.4% incidence of IMAs; however, this could be underestimated because of the limited range of inspection. Early detection of an IMA through careful inspection during microvascular surgery could be beneficial, especially in patients with multiple aneurysms.

Impact of Surgeon Experience on Postoperative Rehemorrhage in Spontaneous Basal Ganglia Intracerebral Hemorrhage

Spontaneous intracerebral hemorrhage (SICH) is of high mortality and morbidity. SICH in the basal ganglia is usually attributed to chronic hypertension. Postoperative rehemorrhage is a severe complication, and it is relative to surgical techniques. A retrospective survey was conducted on 123 patients with basal ganglia SICH who received surgery from January 2015 to January 2019. Postoperative rehemorrhage within 24 hours was recorded. Preoperative clinical parameters, surgeon experience (<10 and >20 years), operation time, surgical approach, and hemostasis technique were recorded and analyzed. The total postoperative rehemorrhage rate was 12.2% (15/123). The univariable analysis showed general surgeons had a higher postoperative rehemorrhage rate than experienced surgeons (30.4% vs. 8.6%, respectively; P= 0.068). The operation time (minutes) in experienced surgeons was significantly longer (164.9 ± 53.5 vs. 137.7±30.8, P= 0.016), but they had a higher chance to locate the responsible vessel (74.2% vs. 40.0%, P= 0.001), respectively. Logistic analysis indicated that experienced surgeons significantly reduced the risk of rehemorrhage (odds ratio [OR], 0.242; P= 0.021). Transsylvian approach was a protective factor for postoperative rehemorrhage (OR, 0.291; P= 0.045). Surgeons' experience plays the most important role in postoperative rehemorrhage. Surgeons with rich experience were willing to spend more time to achieve definitive hemostasis in operation. The use of a transsylvian approach can significantly reduce the rehemorrhage rate. Packing hemostasis with gelatin sponge may increase complications.

Insular cavernous malformation resection through a minipterional, transsylvian approach.

Cavernous malformations of the brain are low-flow vascular lesions that have a propensity to hemorrhage. Extensive surgical approaches are often required for operative cure of deep-seated lesions. A 23-year-old female presented with a cavernous malformation of the left posterior insula with surrounding hematoma measuring up to 3 cm. A minimally invasive (mini-)pterional craniotomy with a transsylvian approach was selected. Endoscopic assistance was utilized to confirm complete resection of the lesion. The minipterional craniotomy is a minimally invasive approach that provides optimal exposure for sylvian fissure dissection and resection of many temporal and insular lesions.The video can be found here: https://youtu.be/9z6_EhU6lxs.

Surgery for epilepsy.

Surgery for epilepsy.

Rare Thyroid Transcription Factor 1–Positive Tumors of the Sellar Region: Barrow Neurological Institute Retrospective Case Series

Granular cell tumors (GCTs), pituicytomas, and spindle cell oncocytomas are rare, nonfunctioning pituitary tumors sharing positive staining of thyroid transcription factor 1. We present our series, the first single-institutional report with long-term surgical follow-up of all 3 tumor types. Our institutional pathology database was queried for these 3 pathologic diagnoses. Clinical records were assessed for clinical presentation, preoperative and postoperative endocrine status, tumor location on imaging, surgical characteristics, pathology results, and tumor recurrence. Data were analyzed for 4 patients with GCTs, 4 with pituicytomas, and 3 with spindle cell oncocytomas. The most common symptoms at presentation were vision changes (64%), headache (55%), endocrine abnormalities (55%), and fatigue (46%). GCTs were the only subtype to present exclusively in the infundibulum and the only subtype in our series to be treated with a transcranial transsylvian approach to resection (n= 2). In our study, in contrast to other reports, estimated blood loss was less than 300 mL in all patients. Imaging confirmed gross total resection in all 11 cases with no known recurrences at a mean (standard deviation) follow-up of 4.7 (3.7) years. We present a single-institution series of rare thyroid transcription factor 1-staining posterior pituitary tumors of the sellar region. Key novel findings include gross total resection with no tumor recurrence at nearly 5 years of mean follow-up and no cases of excess or uncontrolled blood loss. Our findings reinforce the observation that GCTs present in the suprasellar space.

Microsurgical Anatomy and Approaches to the Cerebral Central Core

Through a cadaveric study, we divided the cerebral central core (CCC) into different areas and have proposed a corresponding neurosurgical approach for each sector. As a secondary objective, we analyzed the cortical and subcortical microsurgical anatomy of the CCC. The CCC includes the insula, extreme capsule, claustrum, external capsule, lenticular nucleus, internal capsule, caudate nucleus, and thalamus. Twelve adult human brain hemispheres and one cadaveric head specimen were dissected and studied at the Laboratory of Neuroanatomic Microsurgical of the University of Buenos Aires. Nine cases of CCC neurosurgical pathologies were included in the present study and analyzed. Digital drawings were created of the approaches proposed for each sector of the CCC showing the most relevant surgical details. Photographs of each dissection and measurements obtained were taken. We divided the CCC into a medial, intermediate, and lateral sector, with specific subdivisions for the lateral and medial sectors. The lateral projection of the foramen of Monro was found deep to the third short gyri of the insula with the following distances: anterior insular limen margin, 23.95 mm; posterior insular limen margin, 22.92 mm; superior limiting sulcus, 14.99 mm, and inferior limiting sulcus, 13.76 mm. We have proposed the following approaches: an ipsilateral transcallosal approach, a contralateral transcallosal approach, a choroidal transfissure approach, a trans-splenial approach, transparietal access entering the intraparietal sulcus, and trans-sylvian approach. The preoperative imaging studies should be analyzed using our method to select the most accurate and safe approach. We have provided a description of the limits and anatomy of the CCC using brain dissection, an analysis of operated cases, and useful measurements for the neurosurgeon.

Surgical Approaches to the Thalamus in Relation to the White Matter Tracts of the Cerebrum

Approaching the thalamus from any angle remains a challenge because of its deep-seated location and intimate relations with adjacent important neurovascular structures and functions such as relaying sensory and motor signals and cognition. Our aim was to explore the relationship of the white matter tracts of the cerebrum to the thalamus using a fiber dissection technique, to delineate anatomic principles of approaches to the thalamus, and to discuss the tracts at risk in relation to each approach. The thalamus was subdivided into 6 different regions and 13 approaches were examined in an attempt to describe a surgical road map. To reach the anteroinferior, medial, and lateral parts of the thalamus, the anterior and middle group approaches were used, and to reach the posterosuperior and posteroinferior thalamus, posterior and middle group approaches were used. The anteroinferior zone was the most difficult site to be accessed and the posterosuperior thalamus had the maximum number of alternative approaches. The distal transsylvian approach to the posterosuperior thalamus and the supracarotid infrafrontal approach to the anteroinferior thalamus had the highest number of neural structures severed within the surgical corridor. The infratentorial approaches and the suboccipital transtentorial approach preserve most of the white matter tracts en route to the posterosuperior and medial posteroinferior parts of the thalamus. When the surgical approaches for thalamic lesions are defined, white matter tracts along the surgical route should be taken into consideration.

Surgical morbidity of transsylvian versus transcortical approaches to insular gliomas.

The choice of transsylvian versus transcortical corridors for resection of insular gliomas remains controversial. Functional pathway compromise from transcortical transgression and vascular injury during transsylvian dissection are the primary concerns. In this study, data from a single-center experience with both approaches were compared to determine whether one approach was associated with a higher rate of morbidity than the other. The authors identified 100 consecutive patients who underwent resection of pure insular gliomas at the Barrow Neurological Institute. Volumetric analysis was performed using FLAIR and contrast-enhanced T1-weighted MRI for low- and high-grade gliomas, respectively, for extent of resection (EOR) and diffusion-weighted sequences were used to detect for postoperative ischemia. Step-wise logistic regression analysis was performed to identify predictors of neurological morbidity. Data from 100 patients with low-grade or high-grade insular gliomas were analyzed. Fifty-two patients (52%) underwent a transsylvian approach, and 48 patients (48%) underwent a transcortical approach. The mean (± SD) EOR was 91.6% ± 12.4% in the transsylvian group and 88.6% ± 14.2% in the transcortical group (p = 0.26). Clinical outcome metrics for the 2 groups were similar. Overall, 13 patients (25%) in the transsylvian group and 10 patients (21%) in the transcortical group had evidence of ischemia on postoperative MR images. For both approaches, high-grade histology was associated with permanent morbidity (p = 0.01). For patients with gliomas located within the superior-posterior quadrant of the insula, development of postoperative ischemia was associated with only the transsylvian approach (46% vs 0%, p = 0.02). Areas of restricted diffusion are common on postoperative MRI following resection of insular gliomas, but only a minority of these patients develop permanent neurological deficits. Insular glioma patients with high-grade histology may be at particular risk for developing symptomatic postoperative ischemia. Both the transcortical and transsylvian corridors are associated with reasonable morbidity profiles, although gliomas situated within the superior-posterior quadrant of the insula are more safely accessed with a transcortical approach.

Combined supra-infrasellar approach to pituitary macroadenoma with oculomotor cistern extension: surgical strategy and experience.

Oculomotor cistern extension (OMCE) of pituitary adenoma through the oculomotor triangle may be one of the major characteristics of multi-lobulated adenoma. The OMCE may be hard to remove only through the endonasal approach. We applied the simultaneous combined supra-infrasellar approach to remove pituitary adenoma with relatively large OMCE. Four (7.3%) of 55 consecutive patients with initially operated pituitary macroadenoma (> 10mm) had OMCE. The combined supra-infrasellar approach was adopted in two cases with relatively large OMCE. The simultaneous combined supra-infrasellar approach was performed with the transcranial microscopic transsylvian anterior temporal approach and the nasal endoscopic approach. The medial main mass was removed through the nasal side. The lateral OMCE was also removed through the nasal side by pushing the tumor in the sellar direction from the transcranial side. The oculomotor nerve was confirmed with electrical nerve stimulation. The main medial mass and the OMCE were mostly removed in both cases. Remnant tumor in the cavernous sinus was treated by gamma knife radiosurgery. Endoscopic transsphenoidal removal was performed in the other two cases with relatively small OMCE. Pituitary macroadenomas with OMCE are a newly recognized form of progression with important implications for surgical strategy. The combined supra-infrasellar approach performed with the transcranial microscopic transsylvian anterior temporal approach using electrical nerve stimulation and the nasal endoscopic approach may be useful for this type of multi-lobulated pituitary adenoma.

Impact of the Intracranial Course of Internal Carotid Artery on Optimal Surgical Approach for Posterior Communicating Artery Aneurysms

The anterior temporal approach (ATA) has been reported as suitable for surgical clipping of posteriorly projecting internal carotid artery (ICA) aneurysms. As the ICA follows a variable course, tortuosity of the ICA may affect visualization of the aneurysm. The aim of this study was to investigate the impact of the intracranial course of the ICA and aneurysm projection on surgical approach. Consecutive patients with posterior communicating artery aneurysms treated with clipping at our hospital between May 2015 and April 2018 were retrospectively reviewed. When the transsylvian approach (TSA) could not achieve adequate exposure of the aneurysm, the ATA was subsequently performed. Distance between the ICA and the anterior and posterior clinoid line, angle between the midline and the C1 segment of the ICA, and aneurysm projection were compared between ATA and TSA groups. Of 52 patients (40 ruptured, 12 unruptured), 12 were in the ATA group, and 40 were in the TSA group. Mean ICA-anterior and posterior clinoid distance was significantly shorter in the ATA group than in the TSA group (P= 0.002), and mean midline-C1 angle was significantly larger in the ATA group than in the TSA group (P < 0.0001). The ATA group was associated with a greater frequency of posteriorly projecting aneurysms (12 of 12; 100%) than the TSA group (9 of 40; 22.5%) (P < 0.00001). A low-lying, laterally projecting intracranial ICA and posteriorly projecting aneurysm are predictors of the necessity for the ATA in the surgical clipping of posterior communicating artery aneurysms.

Left Pan-Hippocampal Low Grade Glioma-2-Stage Transsylvian Transventricular and Paramedian Supracerebellar Transtentorial Approaches: 2-Dimensional Operative Video.

The surgical goal for low-grade gliomas (LGGs) is to maximize resection while minimizing morbidity. Pan-hippocampal LGGs extend from the hippocampal head to the hippocampal tail, and involve the parahippocampal gyrus and uncus. Given their anteroposterior extension, they cannot be completely removed with 1 single approach, requiring a 2-stage front-to-back operation. In this video, we present the case of a 52-yr-old man with new onset of generalized seizures and a dominant-side, nonenhancing, pan-hippocampal infiltrative lesion compatible with a low-grade glioma. Preoperative high-definition fiber tractography (HDFT) showed the spatial relationship of the tumor with surrounding fiber tracts, such as the arcuate, inferior fronto-occipital, and middle longitudinal fascicles, and optic radiations. Surgical resection was planned in 2 separate stages. The first stage consisted of a transsylvian transinferior insular sulcus approach to the extra- and intraventricular aspects of the uncohippocampal region. The entire anterior and middle portions of the tumor were successfully removed with minimal morbidity, including transient naming difficulties and permanent superior quadrantanopia. Postoperative HDFT showed preservation of all fiber tracts, except for a portion of Meyer's loop and the inferior-most aspect of the inferior fronto-occipital fascicle. The second stage was completed 8 wk later and consisted of a paramedian supracerebellar-transtentorial approach on sitting position. The posterior portion of the tumor was entirely removed to achieve a complete macroscopic tumor resection. The final diagnosis was IDH1-positive LGG. Pan-hippocampal tumors remain a surgical challenge but accurate knowledge of surgical neuroanatomy and surgical approaches facilitates their safe and effective treatment. The patient signed an informed consent including the use of photographic and video material for educational or academic purposes.

Intracerebral hemorrhage: epidemiology and surgical options from a tertiary care hospital in Eastern Nepal

Background: Intracerebral hemorrhage accounts for 10 to 20% of strokes. Based on the precise site and size of the hematoma, ICH can manifest a range of clinical and radiological deficits. The role of surgical removal of hematoma has by far been controversial, and despite large clinical trials, the efficacy of surgery remains controversial. In this paper, we descried our experience of ICH and its epidemiology along with the outcomes of patients undergoing surgical removal of hematoma secondary to ICH.&#x0D; Patient And Methods: A retrospective observational study was conducted from April to September 2018 in a tertiary care center in Nepal. 102 patients undergoing surgery using trans-cortical, trans-sylvian or endoscopic approaches were included, and their outcomes were assessed using a 5-point GOS at a 6-weeks follow-up.&#x0D; Results: A total of 102 patients were included in the study. Out of these, 54 were males(mean age: 54.7), and 48females (mean age: 56.13). Smoking was common in 42.2% of patients and alcohol intake (15.7%). The site of hematoma was 55.9% basal ganglia bleed and 44.1% hemorrhages of the frontal, occipital, parietal and temporal lobes collectively. Surgical outcomes at a 6-weeks follow up included a mortality of 11.8% (n=12), 27.5% (n=28) with moderate disability, and 60.8% (n=62) with good recovery.&#x0D; Conclusion: The etiology of ICH is attributed to a spectrum of modifiable and non-modifiable risk factors. Treatment strategies should focus on prevention of progression to secondary brain damage. Surgical intervention, if performed during the ideal time-window provides a good outcome in patients with ICH. Further studies are needed to evaluate the efficacy and best treatment strategy.

Left Transsylvian Transcisternal and Transinferior Insular Sulcus Approach for Resection of Uncohippocampal Tumor: 3-Dimensional Operative Video.

The medial temporal lobe can be divided in anterior, middle, and posterior segments. The anterior segment is formed by the uncus and hippocampal head, and it has extra and intraventricular structures. There are 2 main approaches to the uncohippocampal region, the anteromedial temporal lobectomy (Spencer's technique) and the transsylvian selective amygdalohippocampectomy (Yasargil's technique).In this video, we present the case of a 29-yr-old man with new onset of generalized seizures and a contrast-enhancing lesion in the left anterior segment of the medial temporal lobe compatible with high-grade glioma. He had a medical history of cervical astrocytoma at age 8 requiring craniospinal radiation therapy and ventriculoperitoneal shunt placement.The tumor was approached using a combined transsylvian transcisternal and transinferior insular sulcus approach to the extra and intraventricular aspects of the uncohippocampal region. It was resected completely, and the patient was neurologically intact after resection with no further seizures at 6-mo follow-up. The diagnosis was glioblastoma IDH-wild type, for which he underwent adjuvant therapy.Surgical anatomy and technical nuances of this approach are illustrated using a 3-dimensional video and anatomic dissections. The selective approach, when compared to an anteromedial temporal lobectomy, has the advantage of preserving the anterolateral temporal cortex, which is particularly relevant in dominant-hemisphere lesions, and the related fiber tracts, including the inferior fronto-occipital and inferior longitudinal fascicles, and most of the optic radiation fibers. The transsylvian approach, however, is technically and anatomically more challenging and potentially carries a higher risk of vascular injury and vasospasm.Page 1 and figures from Fernández-Miranda JC et al, Microvascular Anatomy of the Medial Temporal Region: Part 1: Its Application to Arteriovenous Malformation Surgery, Operative Neurosurgery, 2010, Volume 67, issue 3, ons237-ons276, by permission of the Congress of Neurological Surgeons (1:26-1:37 in video).Page 1 from Fernández-Miranda JC et al, Three-Dimensio-nal Microsurgical and Tractographic Anatomy of the White Matter of the Human Brain, Neurosurgery, 2008, Volume 62, issue suppl_3, SHC989-SHC1028, by permission of the Congress of Neurological Surgeons (1:54-1:56 in video).

Mapping whole brain connectivity changes: The potential impact of different surgical resection approaches for temporal lobe epilepsy

In neurosurgery there are several situations that require transgression of the temporal cortex. For example, a subset of patients with temporal lobe epilepsy require surgical resection (most typically, en-bloc anterior temporal lobectomy). This procedure is the gold standard to alleviate seizures but is associated with chronic cognitive deficits. In recent years there have been multiple attempts to find the optimum balance between minimising the size of resection in order to preserve cognitive function, while still ensuring seizure freedom. Some attempts involve reducing the distance that the resection stretches back from the temporal pole, whilst others try to preserve one or more of the temporal gyri. More recent advanced surgical techniques (selective amygdalo-hippocamptectomies) try to remove the least amount of tissue by going under (sub-temporal), over (trans-Sylvian) or through the temporal lobe (middle-temporal), which have been related to better cognitive outcomes. Previous comparisons of these surgical techniques focus on comparing seizure freedom or behaviour post-surgery, however there have been no systematic studies showing the effect of surgery on white matter connectivity. The main aim of this study, therefore, was to perform systematic ‘pseudo-neurosurgery’ based on existing resection methods on healthy neuroimaging data and measuring the effect on long-range connectivity. We use anatomical connectivity maps (ACM) to determine long-range disconnection, which is complementary to existing measures of local integrity such as fractional anisotropy or mean diffusivity. ACMs were generated for each diffusion scan in order to compare whole-brain connectivity with an ‘ideal resection’, nine anterior temporal lobectomy and three selective approaches. For en-bloc resections, as distance from the temporal pole increased, reduction in connectivity was evident within the arcuate fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and the uncinate fasciculus. Increasing the height of resections dorsally reduced connectivity within the uncinate fasciculus. Sub-temporal amygdalohippocampectomy resections were associated with connectivity patterns most similar to the ‘ideal’ baseline resection, compared to trans-Sylvian and middle-temporal approaches. In conclusion, we showed the utility of ACM in assessing long-range disconnections/disruptions during temporal lobe resections, where we identified the sub-temporal resection as the least disruptive to long-range connectivity which may explain its better cognitive outcome. These results have a direct impact on understanding the amount and/or type of cognitive deficit post-surgery, which may not be obtainable using local measures of white matter integrity.

Surgical treatment of lenticulostriate aneurysms (a case report and literature review)

The study objective is to describe a rare case of putaminal intracerebral hemorrhage (PICH) results from a rupture of the distal lateral lenticulostriate artery (LSA) aneurysm and to summarize currently available information on its diagnosis and treatment.Materials and methods. A 40-year-old female patient was admitted to the N.V. Sklifosovsky Research Institute of Emergency Medicine. Her arterial pressure was 200/110 mm Hg. Brain computed tomography (CT) revealed a 25 сm3 right-sided PICH with a minimal perifocal edema. CT angiography revealed a saccular aneurysm located in the right distal LSA with the dome of 5 mm and the neck of 2 mm. We performed right frontotemporoparietal osteoplastic craniotomy and used the transsylvian transinsular approach to PICH represented by ruptured while we were removing the blood clots. We performed aneurysm trapping and removed the hematoma.Results. This clinical case demonstrates the possibility of successful microsurgical repair of the distal lateral LSA aneurysm rupture. Six months postoperatively, the patient had complete regression of left leg paresis and partial restoration of left hand functions.Conclusion. This case report appears quite interesting since deep intracerebral hematomas of this etiology are extremely rare. An optimal treatment for LSA aneurysms remains a subject of debate due to the small number of patients with this disorder and limited data on it. Patients with fusiform aneurysms require conservative treatment and dynamic follow-up with periodic cerebral angiography. Patients with typical saccular aneurysms or PICH presenting mass effect should undergo surgical treatment.

Endoscopic Approach of the Insula Through the Anterior Middle Temporal Gyrus: A Feasibility Study in the Laboratory.

Insular glioma surgery still represents a challenge. Nonetheless, advances in microsurgical anatomy and brain mapping techniques have allowed an increase in the extent of resection with acceptable morbidity rates. Transsylvian and transcortical approaches constitute the main surgical corridors, the latter providing considerable advantages and a high degree of reliability. Nevertheless, both surgical corridors yield remarkable difficulties in reaching the most posterior insular region. To study the feasibility of an endoscopic transtemporal approach in brain specimens, with the aim to provide a suitable access for posterior insular region. Four postmortem human hemispheres, embalmed using Klingler's technique, were dissected by means of a 30° rigid endoscope. The specimens underwent magnetic resonance imaging scans and, using the neuronavigation system, we were able to design a safe cortical window and an optimized endoscopic trajectory for the posterior insular dissection. Insular dissection was led subpially through a small 2-cm cortical access, located in the anterior part of the middle temporal gyrus. During the posterior insula dissection, the endoscope allowed for optimized surgical view all along the long gyri, up to the posterior insular point. Anterior insular dissection was accomplished with more difficulties, as the endoscopic trajectory was not aligned to the axis of the short gyri. This new surgical approach provides a favorable transcortical access to reach the most posterior insular portion. It seems to be a promising tool, in combination with intraoperative functional brain mapping, to further improve extent of resection rates in insular glioma surgery.