Preservation of the middle meningeal artery during unruptured aneurysm surgery: an independent risk factor for postoperative chronic subdural hematoma.

Background: Although microsurgical clipping for unruptured aneurysms has become safer and more efficient with modern neurosurgical advances, postoperative chronic subdural hematoma (CSDH) persists as an underrecognized complication. This study investigated the association between preservation of the anterior branch of the middle meningeal artery (MMA) during surgery and CSDH development. Methods: We retrospectively reviewed 120 patients who underwent clipping for unruptured aneurysms at Kyungpook National University Chilgok Hospital between May 2020 and July 2023. We evaluated the patients on the basis of surgical approach-lateral supraorbital (LSO) or standard pterional craniotomy-and the status of the MMA postoperatively. We employed pre-and post-operative MR angiography to assess MMA preservation and used follow-up computed tomography scans to monitor CSDH development. Results: Of the 120 patients, 22 (18.3%) developed CSDH. Univariate analysis revealed that male sex, advanced age, and MMA preservation are risk factors for postoperative CSDH. Multivariate analysis supported these findings, indicating a significant association with the development of CSDH. MMA preservation was reported in 65 patients, of whom 60 and 5 underwent LSO and pterional craniotomy, respectively. Conclusion: Preservation of the anterior branch of the MMA during unruptured aneurysm surgery is a risk factor for postoperative CSDH development. Advanced age and male sex also contribute to the increased risk. These findings highlight the need for further investigation into surgical techniques that could mitigate postoperative CSDH development.

Exoscopic resection of giant olfactory groove meningioma.

Olfactory groove meningiomas represent 8%-13% of all intracranial meningiomas. Gross-total resection for large (4-6 cm) and giant (> 6 cm) cases remains challenging due to their relationship with critical neurovascular structures and extensive frontal lobe edema. A variety of transcranial and endoscopic approaches have been described. This 2D operative video shows the use of a digital 3D exoscope in the removal of a giant olfactory groove meningioma through a lateral supraorbital approach in a 57-year-old woman with visual impairment and apathy. The exoscope provides a very good angulated view of the subfrontal area on both sides of the anterior cranial fossa even through a small craniotomy. The video can be found here: https://stream.cadmore.media/r10.3171/2023.10.FOCVID23125.

A meta-analysis of Lateral supraorbital vs mini Pterional approach in the outcome of rupture and unruptured noncomplex aneurysms’ surgery / Metaanálisis entre el abordaje subfrontal y minipterional en los aneurismas cerebrales no complejos

To determine the characteristics and to compare the functional outcomes and safety of different subfrontal approaches versus mini Pterional (MPT) approaches mainly for the treatment of ruptured noncomplex intracranial aneurysms. This meta-analysis included articles comparing outcomes of brain aneurysms (BAs) – most for the anterior circulation–, using Lateral supraorbital & Supraorbital keyhole (LSO) versus MPT approach. There were six articles left into the final article pool and the total number of patients was 683 (322 in LSO and 361 in the MPT group). In terms of the early and late time of surgery, the LSO seems to be superior over the MPT approach but with heterogeneity (OR −0.21, CI 95% −0.59 to 0.18, and p=0.04) or (OR −0.21, CI 95% −0.69 to 0.28, and p=0.05), and (p=0.02 and I2=68.97%) or (p=0.05 and I2=61.74%) respectively. Regarding the subgroup of patients with the supra-early time of surgery, surgical duration, completed occlusion, technical intraoperative complications, postoperative infection, intraoperative rupture, vasospasm, good and poor neurological outcomes and clinical deterioration, there was no superiority of the one method over the other. Mini or keyhole craniotomy even challenging might be a good option for neurosurgeons. Particularly in ruptured noncomplex aneurysms’ surgery LSO seems to be superior over the MPT approach in terms of the early time and in the late time of surgery but with heterogeneity (AU)

Determinar las características, comparar los resultados funcionales y la seguridad de los diferentes abordajes subfrontales vs. los abordajes minipterionales (MPT) en el tratamiento principalmente de aneurismas intracraneales rotos. Este metaanálisis incluye artículos que comparan los resultados quirúrgicos de los aneurismas cerebrales (mayoría de circulación anterior), utilizando un abordaje supraorbitario o supraorbitario lateral (LSO) frente un abordaje MPT. En el análisis quedaron seis artículos con un número total de pacientes de 683 (322 en el grupo LSO y 361 en el MPT). En cuanto al tiempo de cirugía precoz y tardío de la cirugía, el LSO parece ser superior al abordaje MPT pero con heterogeneidad (OR -0.21, IC 95% -0.59 - 0.18, y p = 0,04) o (OR -0,21, IC 95% -0,69 - 0,28, y p = 0,05), y (p = 0,02 e 12 = 68,97%) o (p = 0,05 e 12 = 61,74%), respectivamente. En cuanto al subgrupo de pacientes con tiempo de cirugía supraprecoz, la duración quirúrgica, la oclusión completa, las complicaciones técnicas intraoperatorias, la infección postoperatoria, la rotura intraoperatoria, el vasoespasmo, los resultados neurológicos y el deterioro, no hubo diferencias en superioridad de un método sobre el otro. Los resultados muestran que tanto la craneotomía MPT como el LSO, podrían ser una buena opción. Particularmente en la cirugía de aneurismas rotos no complejos el abordaje LSO parece ser superior al abordaje MPT en términos del momento inicial y tardío de la cirugía, aunque existe una heterogeneidad en los resultados (AU)

Application of protective superficial temporal artery to middle cerebral artery bypass through the lateral supraorbital approach: Technical note.

OBJECTIVE: The lateral supraorbital (LSO) approach is a minimally invasive craniotomy widely used in the surgical treatment of intracranial aneurysms (IAs). A protective bypass is considered a safety measure in high-risk and complex clipping procedures to maintain distal cerebral flow. However, the protective bypass has so far only been applied through a pterional or larger craniotomy. We aimed to describe the characteristics of the superficial temporal artery to middle cerebral artery (STA-MCA) bypass through the LSO craniotomy to treat complex IAs. METHODS: We retrospectively identified six patients with complex IAs who underwent clipping and a protective STA-MCA bypass through the LSO approach between January 2016 and December 2020. The STA donor artery was harvested through the same curvilinear skin incision with a small extension, and it was anastomosed to the opercular segment of the MCA. Subsequently, aneurysm clipping followed standardized steps. RESULTS: Anastomosis was successful in all patients. Despite requiring temporary occlusion of the parent artery, all aneurysms were successfully clipped without any neurological deterioration. CONCLUSIONS: A protective STA-MCA bypass is feasible through the LSO approach with certain technical modifications. This technique helps protect distal cerebral flow for safe clip placement in the treatment of complex IAs with the associated benefits of a less invasive craniotomy.

A meta-analysis of Lateral supraorbital vs mini Pterional approach in the outcome of rupture and unruptured noncomplex aneurysms' surgery.

To determine the characteristics and to compare the functional outcomes and safety of different subfrontal approaches versus mini Pterional (MPT) approaches mainly for the treatment of ruptured noncomplex intracranial aneurysms. This meta-analysis included articles comparing outcomes of brain aneurysms (BAs) - most for the anterior circulation-, using Lateral supraorbital & Supraorbital keyhole (LSO) versus MPT approach. There were six articles left into the final article pool and the total number of patients was 683 (322 in LSO and 361 in the MPT group). In terms of the early and late time of surgery, the LSO seems to be superior over the MPT approach but with heterogeneity (OR -0.21, CI 95% -0.59 to 0.18, and p=0.04) or (OR -0.21, CI 95% -0.69 to 0.28, and p=0.05), and (p=0.02 and I2=68.97%) or (p=0.05 and I2=61.74%) respectively. Regarding the subgroup of patients with the supra-early time of surgery, surgical duration, completed occlusion, technical intraoperative complications, postoperative infection, intraoperative rupture, vasospasm, good and poor neurological outcomes and clinical deterioration, there was no superiority of the one method over the other. Mini or keyhole craniotomy even challenging might be a good option for neurosurgeons. Particularly in ruptured noncomplex aneurysms' surgery LSO seems to be superior over the MPT approach in terms of the early time and in the late time of surgery but with heterogeneity.

Lateral supraorbital approach for resection of large and giant olfactory groove meningiomas: a single center experience.

BACKGROUND: The lateral supraorbital approach (LSO) provides an optimal access corridor for various skull bases lesions, including olfactory groove meningiomas (OGMs). The aim of this study is to describe the authors' experience with the management of large and giant OGMs utilizing the LSO approach and describe the technical nuances of the procedure. METHODS: A retrospective review of seven patients with large and giant OGMs managed with the LSO approach between 2013 and 2019 was performed. Radiographic and clinical data were recorded and analyzed. RESULTS: Seven patients with large and giant OGMs underwent surgical resection via the LSO approach. Six patients were female, with a median age of 56 years. Patients commonly presented with altered mentation, anosmia, and headaches. The average tumor volume was 120.6 ± 64.7 cm3 with five cases of vascular encasement. Simpson grade II resection was achieved in four patients while Simpson grade IV resection was achieved in three patients. The median length of stay was 2.0 days. The median preoperative Karnofsky Performance Scale (KPS) score was 70, improving to 100 at last postoperative follow-up visit. Two complications were encountered in the form of postoperative cerebrospinal fluid leak in one patient and a transient diplopia in another patient. Tumor recurrence/progression was identified in two patients during a median follow-up time of 65.5 months. Both cases have been managed with adjuvant radiosurgery. CONCLUSION: The LSO approach is a safe and effective minimally invasive transcranial corridor for the management of OGMs that should be part of the armamentarium of skull base neurosurgeons.

Microsurgical Management of Posterior Circulation Aneurysms: A Retrospective Study on Epidemiology, Outcomes, and Surgical Approaches.

Posterior circulation aneurysms have been regarded as the most challenging for endovascular coiling and microsurgical occlusion. The role of microsurgical treatment is gradually being overlooked and diminishing in the trend of endovascular treatment. As microsurgical occlusion of posterior circulation aneurysms is decreasing, we present our relevant experience to evaluate treatment options and surgical approaches. A retrospective study was conducted in the Department of Neurosurgery of the First Affiliated Hospital of Soochow University between 2016 and 2021. Patients with posterior circulation aneurysms treated by clipping, bypass, and trapping were enrolled and followed up for at least six months. We included 50 patients carrying 53 posterior circulation aneurysms, 43 of whom had aneurysm ruptures. The posterior cerebral artery and posterior inferior cerebellar artery were the most common aneurysm locations. Direct clipping was performed in 43 patients, while bypass and trapping was performed in six patients. The retrosigmoid, far-lateral, and midline or paramedian suboccipital approaches were performed for those aneurysms in the middle and lower thirds. Aneurysms in the upper third required the lateral supraorbital approach, pterional approach, subtemporal approach, and occipital craniotomy. The lateral supraorbital approach was utilized in seven patients for aneurysms above the posterior clinoid process. Thirty-four patients recovered well with modified Rankin score 0-3 at discharge. No patient experienced aneurysm recurrence during the mean follow-up period of 3.57 years. Microsurgery clipping and bypass should be considered in conjunction with endovascular treatment as a treatment option in posterior circulation aneurysms. The lateral supraorbital approach is a feasible, safe, and simple surgical approach for aneurysms above the posterior clinoid process.

Olfactory nerve sparing technique for anterior skull base meningiomas: how I do it.

BACKGROUND: Olfactory function preservation is a desirable objective in anterior skull base (ASB) surgery. The "infracerebral-supraolfactory nerve" corridor is presented. METHOD: The technique for preserving the olfactory nerves (OlfNs) in anterior ASB meningioma removal involves the following points: deep knowledge of the ASB vascular and meningeal anatomy, precise preoperative planning, wide and sharp dissection of the OlfNs away from the frontal lobes, gravity-aided frontal lobe retraction, Gelfoam-assisted hemostasis on nervous structures, and access to the lesion through an infracerebral-supraolfactory nerve corridor. CONCLUSIONS: This technique may be a valid option for patients affected by anterior skull base meningiomas with intact preoperative olfactory function.

How I do it: contralateral supraorbital approach for tuberculum sellae meningioma.

BACKGROUND: The resection of tuberculum sellae meningiomas poses a challenge particularly when dealing with the medial aspect of the optic nerve. Dissection of the tumor off the optic nerve is usually carried out in the blind spot "behind" the optic nerve. We describe a contralateral approach for asymmetric tuberculum sellae meningiomas, allowing direct visualization of the medial optic nerve. METHOD: Contralateral lateral supraorbital approach was performed, and complete tumor resection was achieved without any injury to the optic nerve. CONCLUSION: The contralateral approach for asymmetric tuberculum sellae meningioma is an efficient technique allowing improved visualization of the medial optic nerve.

Lateral supraorbital versus pterional approach for parachiasmal meningiomas: surgical indications and esthetic benefits.

The lateral supraorbital (LSO) approach is a minimally invasive modification of the pterional approach. The authors assess the surgical indications and esthetic benefits of the LSO approach in comparison with the pterional approach for parachiasmal meningiomas. From April 2013 to May 2017, a total of 64 patients underwent surgery for parachiasmal meningiomas. Among them, tumor resection was performed with the LSO approach for 34 patients and pterional approach for 30 patients. A retrospective analysis was done on tumor characteristics, surgical outcome, approach-related morbidity, and esthetic outcome between the two approaches. Gross total resection was achieved in 33 of 34 patients (97.1%) with the LSO approach. There were no differences in tumor size, origin, consistency, internal carotid artery encasement, cranial nerve adhesion, and optic canal invasion between the two approaches. The most common tumor origin was the tuberculum sellae for both the LSO and pterional approaches. For tumors with preoperative visual compromise, immediate visual outcome improved or remained stable in 76% and 80.9% with the LSO and pterional approaches, respectively. Surgery time, surgical bleeding, hospital length of stay, and esthetic outcome were significantly shorter and superior with the LSO approach. There were no differences in surgical morbidity and brain retraction injury between the two approaches. The LSO approach can provide a safe, rapid, and minimally invasive exposure for parachiasmal meningiomas compared with the pterional approach. Surgeons must consider tumor size, origin, and extent in determining the resectability of the tumor rather than the extent of exposure.

Selection Strategy for Optimal Keyhole Approaches for Middle Cerebral Artery Aneurysms: Lateral Supraorbital Versus Minipterional Craniotomy.

BACKGROUND/OBJECTIVE: The lateral supraorbital (LS) and minipterional (MP) approaches have been reported for treating intracranial aneurysms as alternative to the pterional approach. We describe our decision making for selecting the minicraniotomy, LS versus MP, for managing noncomplex aneurysms of the middle cerebral artery (MCA), based on the depth of the aneurysm within the Sylvian fissure. METHODS: We report on a consecutive case series of 50 patients who underwent clipping of 54 ruptured/unruptured MCA aneurysms by means of LS or MP craniotomies. The distance between the MCA (M1) origin and the aneurysmal neck is key to selection of the approach: LS was used for MCA aneurysms <15 mm from the M1 origin and MP for MCA aneurysms ≥15 mm from the M1 origin. RESULTS: 11 of 50 patients presented with subarachnoid hemorrhage (10 ruptured MCA aneurysms). Overall, 59 aneurysms were successfully clipped (54 of the MCA). The mean distance between the M1 origin and the aneurysmal neck was 10.1 mm (range, 4-17 mm) for patients treated by LS and 20 mm (range, 15-30 mm) for those treated by MP. All but 1 MCA aneurysms were successfully treated. At last follow-up (mean, 14 months), no reperfusion of the clipped aneurysms was observed. CONCLUSION: Our strategy for selecting the keyhole approach based on the depth of the aneurysm within the Sylvian fissure is efficient and safe. We suggest the use of the LS approach when the aneurysm is <15 mm from the M1 origin and the MP approach when the aneurysm is ≥15 mm from the M1 origin.

Anterior clinoidectomy for paraclinoid aneurysms in Helsinki Neurosurgery.

BACKGROUND: In this video abstract, we present an intradural anterior clinoidectomy for management of some paraclinoid aneurysms. Quick adenosine cardiac arrest performed instead of an anterior clinoidectomy and proximal temporary clipping usually allows us a proximal control of aneurysms in Helsinki Neurosurgery. However, when the neck of the aneurysm remains hidden under the anterior clinoid process, or when some complex aneurysms have reduced space for placing temporary clips obstructing the definitive clipping, anterior clinoidectomy is the most available option. TECHNIQUE: The patient with multiple intracranial aneurysms had a ruptured anterior cerebral artery aneurysm associated with a right middle cerebral artery aneurysm and a right small paraclinoid aneurysm. The patient underwent surgical clipping of all aneurysms by a right lateral supraorbital approach at one-stage surgery. After the associated aneurysms were clipped, the hidden paraclinoid aneurysm required an anterior clinoidectomy for definitive clipping. A small durotomy over the anterior clinoid process was made with microscissors after bipolar coagulation. Subsequently, the anterior clinoidectomy was performed under visual control with the use of an electric high-speed diamond drill (3 mm diameter). The direction and size of the drilling were performed according to the anatomical configuration and exact location of the aneurysm determined by the preoperative radiological analysis of the case. A definitive clip was applied after complete visualization of aneurysm. Postoperative computed tomography angiography demonstrated absence of complications. CONCLUSION: Anterior clinoidectomy is a useful procedure aiming at a proper definitive clipping of paraclinoid aneurysms with challenging locations and configurations. VIDEOLINK: http://surgicalneurologyint.com/videogallery/right-clinoidectomy/.

One burr-hole craniotomy: Lateral supraorbital approach in Helsinki Neurosurgery.

BACKGROUND: In this video abstract, we present a one burr-hole craniotomy for the standard lateral supraorbital approach (LSO) developed by Helsinki Neurosurgery. This is a more aesthetic variant of the classic pterional approach. Presently, the LSO approach is most commonly used at our institution. With the LSO technique, the temporal muscle is just minimally opened close to its superior insertion. Posterior and temporal extension of the craniotomy, furthermore, allows adequate access to the anterior skull base, the sellar and suprasellar regions, the middle cranial fossa, the anterior portion of the Sylvian fissure, and the distal Sylvian fissure. Even though the specific location and size of the lesion may vary, this approach accesses all mentioned structures with a very minimal variation. CASE DESCRIPTION: The patient with an unruptured anterior communicating artery aneurysm is placed in supine position with the head elevated 30 cm from the level of the heart. The head position is determined by the specific location of the lesion. A curved frontotemporal skin incision is made behind the hairline which stops 2-3 cm above the zygoma. Anterior retraction and hemostatic Raney clips placed at the posterior border of the skin flap maintain a clean space for the craniotomy. A burr-hole is made at the level of the temporal line in the frontal bone. After the dura is detached with blunt dissection, a craniotomy is performed to reach the anterior skull base. A few drill holes are made for tack-up sutures and the dura is opened using conventional techniques. The anterior skull base, sellar/suprasellar regions, and select lesions located in the upper basilar region may be accessed through this subfrontal approach. Middle cerebral artery aneurysms and lesions located along the sylvian fissure or in the middle fossas may also be approached with this exposure, but would require further opening of the proximal sylvian fissure. CONCLUSION: There we described the LSO one burr-hole craniotomy technique that may represent a more efficient procedure for performing LSO. VIDEOLINK: "http://surgicalneurologyint.com/videogallery/lso-right-side/"\t"_blank" http://surgicalneurologyint.com/videogallery/lso-right-side/.

Lateral Supraorbital Versus Pterional Approach: Analysis of Surgical, Functional, and Patient-Oriented Outcomes.

BACKGROUND: Recently, the lateral supraorbital (LSO) keyhole variant of the standard pterional (PT) approach has been popularized for anterior skull base surgery, because it provides good anatomic exposition, reduced complications, and better aesthetic and functional results. However, these aspects have been formally compared only by a limited number of studies. We reviewed our experience with 50 consecutive anterior communicating artery (AComA) and A1/A2 aneurysms. Of these 50 patients, 25 had undergone the standard PT approach and 25, the LSO variant. We report the results in terms of exclusion of the aneurysm, postoperative complications, functional/masticatory outcomes, and aesthetic and patient satisfaction. METHODS: From January 2014 to December 2015, 25 patients with unruptured AComA and A1/A2 aneurysms underwent the standard PT craniotomy. From January 2016 to March 2017, another 25 patients underwent the LSO technique. RESULTS: No statistically significant differences were observed in the aneurysmal exclusion rate at angiographic follow-up or major complications. A statistically significant difference in the clinical outcome (Glasgow Outcome Scale) was evident only for the immediate postoperative time and was not significant during the follow-up period. The hospital stay was shorter in the LSO group. Minor complications, patient satisfaction, aesthetics, and functional and masticatory outcomes were significantly better statistically in the LSO group. CONCLUSIONS: The LSO approach demonstrated a lower rate of early clinical minor complications, with a reduction in hospitalization. The LSO approach provides better results for patient satisfaction, masticatory comfort, and cosmetic results. In our experience, the LSO approach is a safe and effective substitute to the standard PT craniotomy to treat unruptured AComA and A1/A2 aneurysms.

[Microsurgical resection of sellar tumors via lateral supraorbital approach: clinical analysis of 20 cases].

Objective: To research the application of lateral supraorbital (LOS) approach for resecting sellar tumors. Methods: Clinical symptoms of 20 patients with surgery via LOS approach were analyzed retrospectively.According to the neuroradiological findings and the improvement of symptoms, and some score scale, the efficacy and safety of LOS were assessed for removing sellar tumors.There were tuberculum sellae meningioma (n=11), craniopharyngioma (n=4), epidermoid cysts (n=4) and pituitary adenoma (n=1). Results: Complete resection was achieved in seventeen patients(85%). The mean operating time was 144.0±54 minutes and the mean intraoperative blood loss was 96.5±51.1 ml.Four patients had post-operative fever, four had endocrine disorders, and one had seizure.No other complications were noted.Fifteen patients had visual function impairment before operation, seven of which were improved while one was aggravated after surgery.The median Karnofsky score (3-46 mon) was 95(0-100) and the Glasgow outcome scale (GOS) at follow-up (3-46 mon) was 4.7(0-5). In general, the outcomes were improved in 18 patients and the mortality was 2. Conclusion: The resection of tumors at sellar region via lateral supraorbital approach is effecient, simple and minimally invasive, which can make the removal of the tumors reliably and safely.It is worthy to be popularized clinically.

Comparison between modified lateral supraorbital approach and pterional approach in the surgical treatment of middle cerebral artery aneurysms.

BACKGROUND: The Middle cerebral artery (MCA) aneurysm is a common type of craniocerebral aneurysm that is prone to rupture and high mortality. The classic surgical approaches are the Pterional approach and the Lateral Supraorbital (LSO) approach, but there are shortcomings. METHODS: This study retrospectively analyzed clinical and imaging data from 181 patients with MCA aneurysm clipping in the Department of Neurosurgery, First Affiliated Hospital of Soochow University between 2011 and 2017. Statistical analysis using parametric and nonparametric tests showed that P values below 0.05 were considered statistically significant. RESULTS: The preoperative GCS score (P = 0.003), Hunt-Hess scale (P < 0.001) and the operating habits of the surgeon (P < 0.001) affected the surgeon to choose a surgical approach. The choice of two surgical methods on the operation time (P < 0.001), skin incision (P < 0.001), complications (P = 0.026), tracheotomy (P = 0.014), prognosis (P = 0.002) were significantly different. Different surgical approaches (P = 0.002), Hunt-Hess scale (P < 0.001), GCS scale (P < 0.001), GCS sorse (P < 0.001), skin incision (P = 0.031) and complications (P < 0.001) are closely related to the prognosis of patients. CONCLUSIONS: Modified LSO approach provides another surgical approach for MCA aneurysm clipping, while avoiding the drawbacks of the LSO approach in the clipping of MCA distal aneurysm.

Comparative analysis on microsurgical removal of craniopharyngioma via lateral supraorbital approach and standard pterional approach.

BACKGROUND: Craniopharyngioma is a kind of intracranial benign tumor that is primarily treated with surgery. At present, a variety of surgical approaches are used for tumor resection. We have conducted a comparative analysis of the two approaches most used in our department. METHODS: The study retrospectively analyzed the clinical data from 65 patients with craniopharyngioma surgically treated by the two approaches mentioned above. Among these patients, 24 were treated by lateral supraorbital (LSO) approach and 41 by standard pterional approach. Indicators including, but not limited to, length of incision, operation time, postoperative pituitary function, urine volume, visual function improvement, and hospitalization were used to compare these two groups of patients. RESULTS: The data shows that there was no significant difference in total tumor resection rate (P = 0.54), postoperative visual field improvement (P = 0.68) and postoperative function of endocrine. However, the LSO approach significantly reduced the operative incision (P = 0.001), shortened the operation time (P = 0.001) and operative complexity, while reducing the incidence of postoperative complications (P = 0.04). CONCLUSIONS: In surgical treatment of craniopharyngioma, LSO approach has similar surgical effect with standard pterional approach, but it can significantly shorten the operation time, reduce surgical trauma and the incidence of complications. Therefore, LSO provides another alternative to surgical approach for microsurgical removal of craniopharyngioma.

The modified lateral supraorbital approach.

PURPOSE: Lateral supraorbital approach is a simpler and quicker method than pterional approach. It provides a more anterior projection when compared to the pterional approach. There are some minor differences of the modified lateral supraorbital approach when compared to lateral supraorbital approach. It is directed more subfrontally and anterior than the pterional and lateral supraorbital approach. MATERIAL AND METHODS: We used modified lateral supraorbital approach in 100 cases between 2012 and 2015 in Medical Park Izmir Hospital/Turkey. The assessed data were as follows: age, gender, Glasgow coma scale at admission, the localization of pathology, the condition of surgical obliteration for aneurysm, excision grade for meningioma, length of stay in the hospital and Glasgow outcoma scale at discharge. RESULTS: Of all patients, 58 (58%) were men and 42 (42%) were women. Our cases were anterior communicating artery aneurysms (41 cases), tuberculum sella and medial sphenoid wing meningiomas (22 cases), middle cerebral artery aneurysms (15 cases), olfactory groove meningiomas (15 cases), anterior choroidal artery aneurysms (4 cases) and posterior communicating artery aneurysms (3 cases). 4 patients died and the mortality rate of the study cohort was 4%. CONCLUSIONS: The MLSA is faster, simpler and less invasive than the PA and LSA.

[Clinical analysis of lateral supraorbital microsurgical approach for ruptured anterior circulation aneurysm].

Objective: To explore the safety and efficiency of lateral supraorbital (LSO) approach for the ruptured anterior circulation aneurysm. Methods: The clinical data of 23 patients with grade Ⅰ-Ⅲ ruptured anterior circulation aneurysm via LSO at the Second Hospital of Shandong University from February 2016 to December 2016 were retrospectively analyzed. The clinical data included their clinical manifestations, radiological finding, microsurgical techniques and follow-up results. Results: All patients were diagnosed as anterior circulation aneurysm by preoperative CT angiography (CTA) or Digital Subtraction Angiography (DSA). They all accepted aneurysm clipping via LSO. The operations carried out smoothly, with no operation related complications. They were followed up for 2 to 12 months, and the Glasgow outcome scales (GOS) were 5 in 18 patients (78.3%), 4 in 2 patients (8.7%), 3 in 2 patients (8.7%), and 1 in 1 patient (4.3%). Conclusion: LSO could provide adequate exposure for the anterior circulation aneurysm, so the clipping could be carried out safely and effectively. LSO is a simple and minimally invasive surgical approach, and when it is used by the skilled master of pterion approach, its advantage could be fully played.

The Extended Lateral Supraorbital Approach and Extradural Anterior Clinoidectomy Through a Frontopterio-Orbital Window: Technical Note and Pilot Surgical Series.

BACKGROUND: Lateral approaches to treat anterior cranial fossa lesions have evolved since the first frontotemporal approach described by Dandy in 1918. We describe a less invasive approach to perform extradural anterior clinoidectomy through a lateral supraorbital (LSO) approach for anterior circulation aneurysms and anterolateral skull base lesions. METHODS: The extended LSO approach involves performing a standard lateral supraorbital craniotomy followed by drilling of the sphenoid wing and lateral wall of the orbit through the frontal bony opening of the LSO approach, without any temporal extension of the craniotomy. This creates a frontopterio-orbital window exposing the periorbita; superior, medial, and anterior aspect of the temporal dura mater; and superior orbital fissure. After unroofing the superior orbital fissure, the meningo-orbital fold is cut, and the temporal dura mater is peeled from the lateral wall of the cavernous sinus to expose the anterior clinoid process allowing a standard opening of the optic canal and anterior clinoidectomy. RESULTS: The extended LSO approach and extradural anterior clinoidectomy allowed access to 4 sphenoid wing/anterior clinoidal meningiomas, 5 anterior circulation aneurysms, 2 temporomesial lesions, and 1 orbital/cavernous sinus abscess. Postoperatively, 2 patients had transient hemiparesis, 2 patients had transient third nerve palsy, and 1 patient had minimal visual field deterioration. All patients had a modified Rankin Scale score ≤1 at 8-week follow-up. CONCLUSION: The extended LSO approach opens a new route (frontopterio-orbital window) to perform extradural anterior clinoidectomy safely and increases surgical exposure, angles, and operability of a less invasive keyhole craniotomy (LSO approach) to treat anterior cranial fossa lesions.