The trans-sylvian trans-petrosal "half & half" approach-a how I do it.

BACKGROUND: Petroclival meningiomas are one of the most challenging tumors to be operated in the realm of neurosurgery. Many approaches have been developed over the years. METHOD: The authors describe the Half & Half (H&H) approach whose main indication is petroclival meningiomas with suprasellar extension. The part of the tumor located above CN III and in the retrochiasmatic space is addressed through a trans-sylvian, while the petroclival portion is through an extradural anterior petrosectomy approach. The wide surgical corridor given by this approach allows extensive tumor resection while avoiding the risk associated with the manipulation of intracavernous neurovascular structures. CONCLUSION: The H&H approach is an effective strategy to maximize the safe resection of petroclival meningiomas.

Microsurgical Resection for Cavernous Malformation of the Uncus: 3D-Operative Video.

Cavernous malformations (CMs) are rare and often oligosymptomatic vascular lesions. The main symptoms include seizure and focal neurologic deficits.1-3 Depending on the symptomatology, location, size, and risk factors for bleeding, like the presence of a developmental venous anomaly, CMs can be highly morbid. Thus surgical resection may be considered. Deep-seated and eloquent CMs, like those in the uncus, can be challenging.4,5 In Video 1, we present a 23-year-old male adult who developed focal seizures (i.e., oral automatisms) after an episode of sudden intense headache 1 year ago. His neurologic examination was unremarkable. The patient consented to the procedure and publication of his image. Nevertheless, his magnetic resonance images showed an uncal 2-cm Zabramski type I CM. We exposed the insula and its limen through a right pterional craniotomy and transsylvian corridor. During the video, we discuss the surgical nuances to access and resect this CM lesion en bloc while preserving important vascular structures and white matter tracts. Postoperative neuroimaging demonstrated total resection. In postoperative day 1, the patient had 1 episode of generalized seizure and evolved with contralateral hemiparesis. The patient had a good recovery and was discharged on postoperative day 21. At the 6-month follow-up, the patient had no new epileptic events and presented complete weakness improvement. Through this minimally invasive and well-known surgical corridor, we preserve the mesial and lateral portion of the temporal lobe, reducing the risk of lesions to the Meyer loop and limbic association area.

Basal vein of Rosenthal classification: the key to venous outflow of the deep sylvian fissure.

OBJECTIVE: Mastery of sylvian fissure dissection is essential to access lesions within the deep basal cisterns. The deep sylvian vein and its tributaries play a major role during access to and beyond the carotid cistern through the sylvian fissure and determine the complexity of microdissection. Preserving the venous outflow during sylvian fissure dissection is the best reliable strategy to prevent postoperative venous strokes or venous hypertension. The authors report the role of the basal vein of Rosenthal (BVR) in the venous outflow pattern of the deep sylvian cistern. METHODS: The authors analyzed 262 consecutive surgical cases involving sylvian fissure dissection from 2015 to 2017. Inclusion criteria were complete sylvian fissure dissection for the treatment of intracranial aneurysms. Exclusion criteria were giant size (aneurysm diameter > 24 mm), meningitis, subarachnoid hemorrhage within the sylvian cistern, absence of 4D CT angiography, and previous surgery. Retrospective radiological and operative video reviews were carried out to assess the association between the superficial sylvian vein and the BVR. The authors analyzed the course of the BVR and the patterns of venous drainage of the sylvian cistern. The surgical difficulty of sylvian fissure dissection was rated by the authors to study the operative significance of the venous patterns encountered. Two clinical cases are described to illustrate the proposed BVR classification. RESULTS: A total of 97 patients met the selection criteria. The most frequent type of BVR was immature (diameter < 0.5 mm, 68%). When the BVR was incompletely developed or absent (immature type), the deep sylvian veins drained through a middle sylvian vein in 70% of cases, requiring advanced sylvian fissure dissection techniques. However, when the BVR was completely developed (32%), the middle sylvian vein was found in a minority of cases (6%), which allowed for an unobstructed transsylvian corridor. Interrater and test-retest reliability of the surgical difficulty was greater than 0.9. CONCLUSIONS: Preoperative assessment of the BVR anatomy is key to predict the deep sylvian venous pattern. The authors provide objective evidence supporting the reciprocal relationship between the type of BVR and the presence of a middle sylvian vein and the deep sylvian venous outflow. An immature BVR should alert the neurosurgeon of the high likelihood of finding a complex deep venous pattern, which may drive surgical planning.

Comparison of two minimally invasive surgical approaches for hypertensive intracerebral hemorrhage: a study based on postoperative intracranial pressure parameters.

BACKGROUND: Increased intracranial pressure (ICP) in patients with hypertensive intracerebral hemorrhage (HICH) has been associated with poor prognosis. The transsylvian insular approach (TIA) and the transcortical (TCA) approach are applied for patients with HICH. We aimed to compare the postoperative ICP parameters of TIA and TCA to identify which procedure yields better short-term outcomes in patients with basal ganglia hematoma volumes ranging from 30 to 50 mL. METHODS: Eighty patients with basal ganglia hematomas 30-50 mL were enrolled in this study. Patients were implanted with ICP probes and divided into TIA and TCA groups according to the procedure. The ICP values were continuously recorded for five days at four-hour intervals. Short-term outcomes were evaluated using the length of hospitalization and postoperative consciousness recovery time. RESULTS: No statistically significant differences were found in age, sex, GCS score at admission, hematoma volume, and hematoma clearance rate (p > 0.05). The results showed that postoperative initial ICP, ICP on the first postoperative day, mean ICP, DICP20 mmHg × 4 h, postoperative consciousness recovery time, the length of hospitalization, mannitol utilization rate and the mannitol dosage were lower in the TIA group than in the TCA group (p < 0.05). Postoperative consciousness recovery time was positively correlated with ICP on the first postoperative day, and the length of hospitalization was positively correlated with mean ICP. CONCLUSIONS: TIA is more effective than TCA in improving the short-term outcomes of patients with basal ganglia hematoma volumes ranging from 30 to 50 mL according to comparisons of postoperative ICP parameters.

Half-and-Half Approach for Multiple Aneurysms at the Superior Cerebellar and Middle Cerebral Arteries.

Aneurysms at the superior cerebellar artery (SCA) are commonly treated endovascularly because of their location around the basilar artery,1,2 but they are not intimately related with thalamoperforators. Therefore in younger patients, those with wide-necked aneurysms, or those with multiple ipsilateral aneurysms, surgery remains a treatment option.3 We present a 52-year-old woman with dizziness in whom multiple, unruptured intracranial aneurysms were identified. Imaging demonstrated a 9-mm right-sided SCA aneurysm and 5-mm right and mirror 3-mm left M1 segment middle cerebral artery aneurysms. The patient gave consent to undergo surgery after counseling regarding her treatment options. A pterional and temporal craniotomy was performed to allow for half-and-half subtemporal and transsylvian approaches (Video 1). Here, we discuss the nuances of the approach related to the anatomy of SCA aneurysms. The challenges of the surgery can be mediated with techniques including division of the tentorium for enhanced exposure and early proximal control with temporary clinping or the use of adenosine (cardiac arrest). Our patient remained neurologically stable postoperatively and in 1-year follow-up. SCA aneurysms are easily visualized by the subtemporal and transsylvian approaches; they are frequently located adjacent to the posterior cerebral artery above and the SCA below. A modified transcavernous approach using the orbitozygomatic craniotomy has been described for access to basilar tip aneurysms.4 While comparable, this case demonstrates the efficient workflow to clip multiple aneurysms using a single, combined approach. In patients with multiple aneurysms presenting ipsilaterally or with comorbid conditions that complicate endovascular embolization, surgery should be considered as a definitive and safe treatment strategy. The patient consented to publication.

Orbitozygomatic Transsylvian Resection of a Craniopharyngioma: A Step-by-Step Guide.

Adamantinomatous craniopharyngioma (ACP) is a rare sellar region tumor seen in 0.5-2 cases per million persons each year,1 presenting a bimodal distribution that peaks at 5-15 years in children and 45-60 years in adults.2 Arising from embryonic remnants of the Rathke pouch epithelium, ACPs are associated with calcifications in 90% of cases and grow cranially toward the floor of the diencephalon.1 Craniopharyngiomas are benign but locally aggressive tumors, with microsurgery being the best chance of cure.3 The natural history is to compress the optic apparatus and hypothalamic-pituitary axis as they expand, with a propensity to encase the carotids. Endoscopic transbasal approaches have gained wide acceptance in the management of these tumors.4-6 However, open microsurgical approaches via pterional and orbitozygomatic craniotomies afford wider visualization of different corridors that help mitigate the surgical risks.7-9 The orbitozygomatic craniotomy allows lesions that extend above the optic chiasm to be safely approached from an inferior-to-superior corridor.9 The wide exposure of the basal arachnoid cisterns allows protection of the lenticulostriate perforators during resection.8-11 We demonstrate a step-by-step orbitozygomatic approach with dissection of the sylvian, carotid, carotid-oculomotor, chiasmatic, and lamina terminalis cisterns that allowed safe resection of a third ventricular ACP. The patient was a male in his 70s, who presented with progressive headaches and visual impairment. Magnetic resonance imaging showed a multicystic suprasellar lesion extending through the third ventricle. The surgery was performed with no complication (Video 1). Postoperative vision stabilized, and magnetic resonance imaging showed complete resection.

Endoport Assisted Endoscopic Surgery for Hypertensive Basal Ganglia Hemorrhage by Transsylvian Approach: Technical Nuances and Preliminary Clinical Results.

BACKGROUND: There is no clear evidence on the indication and surgical approaches on evacuating basal ganglia hemorrhage caused by hypertensive bleeding. Some studies have shown that minimally invasive approaches have therapeutic potentials, but its benefits remain inconclusive. We describe an endoport assisted endoscopic transsylvian approach for basal ganglia hemorrhage evacuation. We evaluate the safety and efficacy of this approach in a cohort study. METHODS: We included 19 patients (mean age 57 years) who underwent the surgery at a single county-level hospital in Yunan Province, China. The majority had a Glasgow coma scale between 9 and 12 on admission. The midline shift ranged from 16-29 mm (mean 19 mm). Hematoma volume ranged from 46 to 106 ml (mean 67 ml). Six patients (31.6%) presented with intraventricular hemorrhage. RESULTS: All patients achieved greater than 90% decrease in hematoma volume at postoperative computed tomography scan. The average operative time was 115 minutes and average blood loss of 44 ml. The most common postoperative complication was pulmonary infection (63.2%). No rebleeding, seizure, infectious meningitis, or postoperative mortality was observed. A total of 17 patients (89.5%) achieved good functional recovery at follow up within 90 days after surgery (Glasgow outcome scale 4-5) and 2 patients had severe disability (Glasgow outcome scale 3). CONCLUSIONS: Endoport assisted endoscopic surgery through transsylvian approach is safe and effective treatment for hypertensive basal ganglia hemorrhage. The majority of patients have good functional recovery and the rate of severe complications is low.

Evaluation of Venous Structures that Are Involved in Transsylvian Approach Using 3D Rotational Venography.

In the transsylvian (TS) approach, as characterized by clipping surgery, the presurgical visualization of the superficial middle cerebral vein (SMCV) can help change the surgical approach to ensure safe microsurgery. Nevertheless, identifying preoperatively the venous structures that are involved in this approach is difficult. In this study, we investigated the venous structures that are involved in the TS approach using three-dimensional (3D) rotational venography (3D-RV) and evaluated the effectiveness of this method for presurgical simulation. Patients who underwent 3D-RV between August 2018 and June 2020 were involved in this retrospective study. The 3D-RV and partial maximum intensity projection images with a thickness of 5 mm were computationally reconstructed. The venous structures were subdivided into the following three portions according to the anatomic location: superficial, intermediate, and basal portions. In the superficial portion, predominant frontosylvian veins were observed on 31 (41%) sides, predominant temporosylvian veins on seven (9%) sides, and equivalent fronto- and temporosylvian veins on 28 (37%) sides. The veins in the intermediate (deep middle cerebral and uncal veins) and basal portions (frontobasal bridging veins) emptied into the SMCV on 57 (75%) and 34 (45%) sides, respectively. The 3D-RV images were highly representative of the venous structures observed during microsurgery. In this study, 3D-RV was utilized to capture the details of the venous structures from the superficial to the deep portions. Presurgical simulation of the venous structures that are involved in the TS approach using 3D-RV may increase the safety of microsurgical approaches.

Hematoma evacuation based on active strategies versus conservative treatment in the management of moderate basal ganglia hemorrhage: A retrospective study.

Objective: The internal capsule of the basal ganglia is vulnerable to direct pressure from the hematoma and to secondary damage from toxic products of hemorrhage. Our study evaluated the risk and benefits of active strategies including ultra-early surgery and hematoma evacuation through a transsylvian-transinsular approach for moderate basal ganglia hemorrhage. Methods: We retrospectively collected patients with moderate basal ganglia hemorrhage in two hospitals. The conservative group contained 51 patients who had the best medical treatment, and the surgery group contained 36 patients who were treated with hematoma evacuation through a transsylvian-transinsular approach within 6 h from ictus. Motor function of upper and lower limbs recorded with the motor sub-score of NIHSS (m-NIHSS) at the baseline, 7 days, 30 days, and 90 days, the modified Rankin Scale (mRS), and Barthel Index (BI) scores at 30 and 90 days were compared between the two groups. Good recovery was defined as an m-NIHSS of 0-2 and poor recovery as 3-4. Favorable prognosis was defined as an mRS of 0-3 and unfavorable prognosis as 4-5. Results: The mean time from ictus to surgery was 250.3 ± 57.3 min. The good recovery proportions of upper and lower limbs in the surgery group were significantly higher than that in the conservative group (p < 0.05) at 7 days after hemorrhage. The good recovery proportion of upper limbs was significantly higher in the surgery group than in the conservative group (p < 0.05) at 3 months after hemorrhage. Living ability using BI scores was significantly higher in the surgery group than the conservative group (p < 0.05) at 3 months after hemorrhage. The favorable prognosis proportion had no statistically significant difference between the two groups at 3 months after hemorrhage. Conclusions: Ultra-early hematoma evacuation through a transsylvian-transinsular approach are active strategies for moderate basal ganglia hemorrhage and have potential advantages in improving motor function recovery and daily living. The postoperative rebleeding rate does not increase simultaneously.

A Novel Surgical Classification of the Sylvian Fissure and Its Implications on the Clinical and Radiological Outcomes of Patients Undergoing Clipping for Unruptured Middle Cerebral Artery Aneurysms.

BACKGROUND: The main access route for middle cerebral artery (MCA) aneurysms is the transsylvian approach. Although Sylvian fissure (SF) variations have been assessed, none have examined how this affects MCA aneurysm surgery. The objective of this study is to investigate how SF variants affect clinical and radiological outcomes for surgically-treated unruptured MCA aneurysms. METHODS: This retrospective study examined consecutive unruptured MCA aneurysms in 101 patients undergoing SF dissection and aneurysm clipping. SF anatomical variants were categorized using a novel functional anatomical classification: Type I: Wide straight, Type II: Wide with frontal and/or temporal opercula herniation, Type III: Narrow straight, and Type IV: Narrow with frontal and/or temporal opercula herniation. The relationships between SF variants and postoperative edema, ischemia, hemorrhage, vasospasm, and Glasgow Outcome Scale (GOS) were analyzed. RESULTS: Study included 101 patients (53.5% women), 60.9 ± 9.4 (range 24-78) years. SF types were 29.7% Type I, 19.8% Type II, 35.6% Type III, and 14.9% Type IV. The SF type with the highest proportion of females was Type IV (n = 11, 73.3%), while it was Type III for males (n = 23, 63.9%) (P = 0.03). There were significant differences between SF types, ischemia, and edema (P < 0.001, P = 0.008, respectively). Although narrow SF types had poorer GOS scores (P = 0.055), there were no significant differences between SF types and GOS, postoperative hemorrhage, vasospasm, or hospital stay. CONCLUSIONS: Sylvian fissure variants may impact intraoperative complications during aneurysm surgery. Thus, presurgical determination of SF variants can predict surgical difficulties, thereby potentially reducing morbidity for patients with MCA aneurysms and other pathologies requiring SF dissection.

Transanterior Limiting Sulcus of the Insula Approach: Novel Surgical Approach to the Ventral Striatum Region.

BACKGROUND: Lesions in the ventral striatum region (above the anterior perforated substance) are a challenge for neurosurgeons due to their direct relationship with the lenticulostriate arteries, which difficult the surgical access. The standard approaches for this region include the following: 1) transfrontal approach, 2) transanterior perforating substance approach, 3) transcallosal transventricular approach, and 4) pterional transsylvian-transinsular route. In this study, we aimed to describe a novel anatomical approach through the anterior limiting sulcus of the insula in order to access the ventral striatum. METHODS: We reviewed the literature and performed a detailed dissection of this region by using Klingler's technique with brain specimens injected with silicone, paying special attention to the white fibers and lenticulostriate arteries, and provided a description of an illustrative case of a cavernous malformation. RESULTS: Neuroanatomical dissections showed that the lenticulostriate arteries had an inverted C-shaped anterior concavity, leaving less significant vascular relationships in the depth of the anterior limiting sulcus of the insula. In the case we described, the cavernous malformation was completely resected and the patient was discharged without any neurological deficits. CONCLUSIONS: The transanterior limiting sulcus of the insula approach to the ventral striatum offers a safe access route for selected cases and can be performed on the basis of anatomical references. Three-dimensional understanding of the intrinsic brain architecture and its relationships with vascular structures in this specific area is important and can be acquired mainly through laboratory training.

Morphological Analysis of the Sylvian Fissure Stem to Guide a Safe Trans-sylvian Fissure Approach.

The sylvian fissure stem and its deep cisternal part (SDCP) consist mainly of the orbital gyrus (OG) and anterior medial portion of the temporal lobe. SDCP's adhesion has been found to make a trans-sylvian approach difficult due to the various patterns of adhesion. Thus, in this study, we aim to clarify the morphological features of the SDCP, and to guide a safe trans-sylvian approach. We retrospectively classified the morphology of the SDCP in 81 patients into 3 types (tight, moderate, loose type) according to the degree of adhesion of the arachnoid membrane and analyzed the morphological features of the OG and the temporal lobe using intraoperative video images. In addition, we have retrospectively measured each width of the SDCP's subarachnoid space at the three points (Point A, lateral superior portion; Point B, downward portion; Point C, medial inferior portion of SDCP) and analyzed their relationship to the degree of adhesion using the preoperative coronal three-dimensional computed tomography angiography (3D-CTA) images of 44 patients. As per the results, SDCP's adhesions were determined to be significantly tighter in cases with large OG and young cases. The temporal lobe had four surfaces (posterior, middle, anterior, and medial) that adhered to the OG in various patterns. The tighter the adhesion between the OG and each of the three distal surfaces of the temporal lobe, the narrower the width of the subarachnoid space at each point (A, B, C). Understanding of the morphological features of the SDCP, and estimating its adhesion preoperatively are useful in developing a surgical strategy and obtaining correct intraoperative orientation in the trans-sylvian approach.

Surgical Approach to Thalamic Tumors.

Thalamic tumors are deep-seated lesions. Recent improvements in therapeutic approaches and surgical techniques have allowed a more accurate approach to these lesions and a reduction in morbidity and mortality. In this article, the various surgical approaches for the resection of thalamic tumors are described. Each of these approaches has its own indications and risk of complications. Resection of thalamic tumors needs specific anatomical knowledge, especially the vascular anatomy of the region and the thalamic peduncles.

Early Exposure of the Dorsal Surface of M1 Segment via the Distal Transsylvian Approach for Clipping of Anteroinferior-Projecting Middle Cerebral Artery Bifurcation Aneurysms.

Background Middle cerebral artery bifurcation (MCAB) aneurysms are common intracranial aneurysms. Anteroinferior-projecting MCAB aneurysms, with M1 segment usually embedded into the deep part of the Sylvian fissure, cause some surgical challenges. The distal transsylvian approach (DTSA) allows M1 exposure from the dorsal surface for proximal control in the early step. Therefore, this study aimed to demonstrate the efficacy and safety of DTSA for clipping anteroinferior-projecting MCAB aneurysms. Methods Among 97 patients with MCA aneurysms, 13 with anteroinferior-projecting MCAB aneurysms who underwent aneurysm clipping via the DTSA between June 2018 and January 2021 were retrospectively evaluated for the aneurysm obliteration rate, surgical complications, and outcomes. Results Ten patients (76.9%) had ruptured MCAB aneurysms and three (23.1%) had incidentally discovered unruptured MCAB aneurysms. Favorable outcome was achieved in 100% of patients with good grade. The complete aneurysm obliteration rate was 100% without intraoperative lenticulostriate artery injury. Twelve (92.3%) patients had early identified distal M1 segment for proximal control, and one (7.7%) patient had premature rupture of aneurysm that achieved favorable outcome at 3 months postoperatively. Difficult M1 exposure and premature rupture occurred in the patient with MCAB located above the Sylvian fissure line. Permanent postoperative neurological deficit was detected in one patient due to severe vasospasm. Conclusion DTSA, which simplify the early exposure of the dorsal surface of distal M1, is safe and effective for clipping anteroinferior-projecting MCAB aneurysms without extensive Sylvian fissure dissection. High-positioned MCAB requires careful dissection of the aneurysm neck with consideration of tentative clipping preparation.

INSULA GLIOMAS: CORRELATION BETWEEN THE TYPE OF APPROACH (TRANSYLVIAN X TRANSCORTICAL) WITH EXTENT OF RESECTION, MORBIDITY AND SURVIVAL / GLIOMAS DA ÍNSULA: CORRELAÇÃO ENTRE O TIPO DE ABORDAGEM (TRANSILVIANA X TRANSCORTICAL) COM EXTENSÃO DA RESSECÇÃO, MORBIDADE E SOBREVIDA

Background: Insula tumors are responsible for up to 25% of low-grade gliomas and 10% of high-grade gliomas. The insula has a complex anatomy, including an eloquent cortex and intimate contact with an arterial vascularization responsible supplying the motor and language systems. Using transsylvian and transcortical corridors for resect insular gliomas remains controversial, and the main concerns behind this are vascular injury during transsylvian dissection and functional impairment in transcortical access. Aim: Observe if there are differences in the extent of lesion resection, postoperative morbidity or survival between the two approaches. Method: 55 patients who underwent resection of insular gliomas by the senior author (GRI) were evaluated, and data related to sex, age at the time of surgical procedure, presence of refractory epilepsy, side of the lesion, pre- and postoperative tumor volumetry, Yasargil and Berger-Sanai classification, encasement of lenticulostriate arteries, neurological examination, and survival were collected. Results: Thirty-one patients (56.4%) underwent a transsylvian approach and 28 patients (43.6%) underwent a transcortical approach. The extent of resection (EOS)> 90% was 61.3% in the transsylvian group and 45.8% in the transcortical group (p = 0.385). The transsylvian approach was chosen for most of the Yasargil type 3 tumors. Late postoperative evaluations of the 2 groups were similar. Conclusions: The transsylvian and transcortical approaches do not present any significant difference in relation to the degree of resection (p = 0.385), survival (p = 0.204), or results in neurological deficits in the late postoperative period.

Racional: Os tumores da ínsula são responsáveis por até 25% dos gliomas de baixo grau e 10% dos de alto grau. A ínsula apresenta uma anatomia complexa, incluindo um córtex eloquente e íntimo contato com uma vascularização responsável pelo suprimento arterial para o sistema motor e de linguagem. A escolha de corredores transsilviano ou transcortical para ressecção de gliomas insulares permanece controversa, e as principais preocupações são a lesão vascular durante a dissecção transilviana e o comprometimento funcional no acesso transcortical. Objetivo: Comparar se há diferença entre a extensão da ressecção da lesão, a morbidade pós operatória ou sobrevida entre as duas abordagens. Método: Foram avaliados 55 pacientes submetidos à ressecção de gliomas insulares e extraídos os dados referentes ao sexo, idade na data do procedimento cirúrgico, presença de 2 epilepsia refratária no pré-operatório, lado da lesão, o volume da lesão em cm3 , calculados a partir da RM encefálica pré-operatória, classificação dos tumores insulares, a técnica cirúrgica utilizada, monitorização intraoperatória, grau histológico obtido através do exame anatomopatológico, extensão da ressecção cirúrgica no pósoperatório, exame neurológico no pré-operatório, pós-operatório tardio, avaliado em 6 meses, além do seguimento evolutivo até dezembro de 2020. Resultados: Foram analisados dados de 55 pacientes com gliomas insulares de baixo ou alto grau. Trinta e um pacientes (56,4%) foram submetidos a abordagem transilviana, e 28 pacientes (43,6%) a abordagem transcortical. A extensão da ressecção (EOR) > 90% foi de 61,3% no grupo transsilviano e 45,8% no grupo transcortical (p = 0,385). A avaliação pós-operatória tardia para os 2 grupos foi semelhantes. No geral, 8 pacientes (25,8%) no grupo transsilviano e 5 pacientes (20,8%) no grupo transcortical apresentou déficit neurológico persistente no pós- operatório tardio. A sobrevida em 24 meses é de 81,3% no grupo transcortical e 92% no transcortical. Conclusões: A abordagem transilviana e transcortical não apresentam diferença significativa em relação ao grau de ressecção (p=0,385), na sobrevida (p=0,204) e na presença de déficit no pósoperatório tardio.

Surgical management of an abscess of the insula.

Background: Mass lesions within the insular are diagnostically and surgically challenging due to the numerous critical cortical, subcortical, and vascular structures surrounding the region. Two main surgical techniques - the transsylvian approach and the transcortical approach - provide access to the insular cortex. Of the range of pathologies encountered, abscesses in the insula are surprisingly rare. Case Description: A 34-year-old patient was admitted for surgical resection of a suspected high-grade glioma in the insula of the dominant hemisphere. A rapid clinical decline prompted emergent neurosurgical intervention using a transsylvian approach. Surprisingly, abundant purulent material was encountered on entering the insular fossa. Pathological analysis confirmed an insular abscess, although a source of infection could not be identified. The patient required a second evacuation for reaccumulation of the abscess and adjuvant corticosteroids for extensive cerebral edema. Conclusion: An abscess located in the insular cortex is an incredibly rare occurrence. Surgical management using the transsylvian approach is one option to approach this region. Familiarity with this approach is thus extremely beneficial in situations requiring emergent access to the dominant insula when awake mapping is not feasible. In addition, treatment of abscesses with adjuvant corticosteroids is indicated when extensive, life-threatening cerebral edema is present.

Dissection of the Sylvian Fissure in the Trans-sylvian Approach Based on the Morphological Classification of the Superficial Middle Cerebral Vein.

The superficial middle cerebral vein (SMCV) is one of the main factors that can impede a wide opening of the sylvian fissure. To reveal the most efficient SMCV dissection for a wide operative field while preserving the veins in the trans-sylvian approach, we retrospectively investigated the SMCVs through intraoperative video images. We characterized the SMCV as composed of the frontosylvian trunk (FST; receiving frontosylvian veins [FSVs] or parietosylvian veins [PSVs]), the temporosylvian trunk (TST; receiving temporosylvian veins [TSVs]), and the superficial middle cerebral common trunk (SMCCT; receiving both FSV/PSV and TSV), and classified the SMCVs of the 116 patients into 5 types based on the morphological classification of the SMCV. Type A SMCV (60.4%) with the SMCCT anastomosed to the frontal side had few bridging veins (BVs) between the SMCCT and the temporal side during dissection. Type B (7.8%) had the SMCCT with no anastomoses to the frontal side. In Type C (17.2%) consisting of the FST and TST and Type D (12.9%) with a merging of the vein of Trolard and Labbé posteriorly and the SMCVs dividing into the FST and the TST again proximally, there were few BVs between the FST and the TST during dissection. Finally, in Type E (1.7%) showing an undeveloped SMCV, there were no BVs between the frontal and the temporal lobes. Postoperative venous infarction occurred in 2.6%. Morphological classification of the SMCV can inform appropriate dissection line to create a wide operative field while preserving the veins in the trans-sylvian approach.

Anatomical Predictors of Transcranial Surgical Access to the Suprasellar Space.

Objective The suprasellar space is a common location for intracranial lesions. The position of the optic chiasm (prefixed vs. postfixed) results in variable sizes of operative corridors and is thus important to identify when choosing a surgical approach to this region. In this study, we aim to identify relationships between suprasellar anatomy and external cranial metrics to guide in preoperative planning. Methods T2-weighted magnetic resonance images (MRIs) from 50 patients (25 males and 25 females) were analyzed. Various intracranial and extracranial metrics were measured. Statistical analysis was performed to determine any associations between metrics. Results Interoptic space (IOS) size correlated with interpupillary distance (IPD; a = 7.3, 95% confidence interval [CI] = 4.5-10.0, R 2 = 0.3708, p = 0.0009). IOS size also correlated with fixation of the optic chiasm, for prefixed chiasms ( n = 7), the mean IOS is 205.14 mm 2 , for normal chiasm position ( n = 33) the mean IOS is 216.94 mm 2 and for postfixed chiasms ( n = 10) the mean IOS is 236.20 mm 2 ( p = 0.002). IPD correlates with optic nerve distance (OND; p = 0.1534). Cranial index does not predict OND, IPD, or IOS. Conclusion This study provides insight into relationships between intracranial structures and extracranial metrics. This is the first study to describe a statistically significant correlation between IPD and IOS. Surgical approach can be guided in part by the size of the IOS and its correlates. Particularly small intraoptic space may guide the surgeon away from a subfrontal approach.

Complication avoidance: resection of the insular glioma complicated by iatrogenic injury to the lenticulostriate artery.

BACKGROUND: Neurosurgical resection of insular gliomas is complicated by the risk of iatrogenic injury to lenticulostriate arteries (LSAs). METHOD: We provide a description, figures, and a video to illustrate the clinical case in which the LSA was damaged during the resection of insular glioma. Cadaveric dissection from our anatomical laboratory and our 3D anatomical model provided relevant surgical anatomy of the insula. CONCLUSION: Proximal dissection of the Sylvian fissure up to the most lateral LSA, the emergence of the beige putamen, and the lenticulostriate veins are anatomic landmarks that allow reducing the risk of damaging the intraparenchymatous segment of the LSAs.

Transsylvian Insular Glioma Surgery: New Classification System, Clinical Outcome in a Consecutive Series of 79 Cases.

BACKGROUND: Surgery of insular glial tumors remains a challenge because of high incidence of postoperative neurological deterioration and the complex anatomy of the insular region. OBJECTIVE: To explore the prognostic role of our and Berger-Sanai classifications on the extent of resection (EOR) and clinical outcome. METHODS: From 2012 to 2017, a transsylvian removal of insular glial tumors was performed in 79 patients. The EOR was assessed depending on magnetic resonance imaging scans performed in the first 48 h after surgery. RESULTS: The EOR ≥90% was achieved in 30 (38%) cases and <90% in 49 (62.0%) cases. In the early postoperative period, the new neurological deficit was observed in 31 (39.2%) patients, and in 5 patients (6.3%), it persisted up to 3 mo.We proposed a classification of insular gliomas based on its volumetric and anatomical characteristics. A statistically significant differences were found between proposed classes in tumor volume before and after surgery (P < .001), EOR (P = .02), rate of epileptic seizures before the surgical treatment (P = .04), and the incidence of persistent postoperative complications (P = .03).In the logistic regression model, tumor location in zone II (Berger-Sanai classification) was the predictor significantly related to less likely EOR of ≥90% and the maximum rate of residual tumor detection (P = .02). CONCLUSION: The proposed classification of the insular gliomas was an independent predictor of the EOR and persistent postoperative neurological deficit. According to Berger-Sanai classification, zone II was a predictor of less EOR through the transsylvian approach.