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.

Pterional approach for tuberculum sellae meningiomas: a 17-year single-center experience

OBJECTIVE

Tuberculum sellae meningiomas (TSMs) are typically in the proximity of the optic nerves and the optic chiasm, thus making the primary aim of surgery the enhancement or stabilization of the patients' visual acuity. The authors therefore undertook a retrospective review of their 17-year experience with the pterional approach to ascertain the resection rate, neurological outcome, and visual outcome.

METHODS

Patients who underwent TSM surgery between September 2003 and December 2020 at the authors' institution were retrospectively evaluated. Patient demographics, tumor characteristics, surgical parameters, postoperative visual outcomes, and complications were analyzed. Gross-total resection (GTR) and subtotal resection (STR) rates were assessed, along with the impact of surgical approach on visual outcomes.

RESULTS

A total of 71 patients with a mean age of 56.9 ± 14.3 years were enrolled in the study. The mean tumor volume was 10.2 ± 12.8 cm3. Postoperatively, 38.7% of patients experienced visual improvement, 45.2% had stable visual acuity, and 16.1% showed visual deterioration. Ipsilateral or contralateral surgical approaches were performed based on the side of the most affected visual acuity. No significant difference in postoperative visual outcomes was observed between the two approaches. GTR was achieved in 84.0% and STR in 16.0%. Minor complications occurred in 3 patients (4.2%), while major complications were found in 4 patients (5.6%). Seven patients (9.8%) showed recurrent tumor growth after 53 months. Progression-free survival after GTR was 123.9 ± 12.9 months, and it was 59.3 ± 13.2 months after STR.

CONCLUSIONS

This study highlighted the finding that TSMs can be successfully resected using a transcranial pterional approach with a low risk of complications and sufficient visual outcomes. Further studies with larger sample sizes are warranted to confirm these findings and optimize surgical strategies for TSM resection.

Pterional Approach for Anterior Skull Base Midline Meningiomas against "The More The Merrier" Approach: An Institutional Experience

Objective  Anterior midline skull base meningiomas involving olfactory groove, planum sphenoidale, and tuberculum sellae were usually managed with bifrontal craniotomy until the dawn of advanced microsurgical techniques. With the emergence of microsurgical techniques, midline meningiomas could be tackled solely from a unilateral pterional approach. We present our experience with pterional approach in managing anterior skull base midline meningiomas, including the technical nuances and outcomes. Methods  Fifty-nine patients who underwent excision of anterior skull base midline meningiomas through a unilateral pterional craniotomy between 2015 and 2021 were retrospectively analyzed. The surgical technique and patient outcomes in the context of visual, behavioral, olfaction, and quality of life were evaluated during the follow-up. Results  A total of 59 consecutive patients were assessed over an average follow-up period of 26.6 months. Twenty-one (35.5%) patients had planum sphenoidale meningioma. Olfactory groove and tuberculum sellae meningioma groups consist of 19 (32%) patients each. Visual disturbance was the predominant symptom with almost 68% of patients presented with it. A total of 55 (93%) patients had complete excision of the tumor with 40 patients (68%) achieving Simpson grade II excision, and 11 (19%) patients had Simpson grade I excision. Among operated cases, 24 patients (40%) had postoperative edema among which 3 (5%) patients had irritability and 1 patient had diffuse edema requiring postoperative ventilation. Only 15 (24.6%) patients had contusion of the frontal lobe and were managed conservatively. Five patients (50%) with seizures had an association with contusion. Sixty-seven percent of patients had improvements in vision and 15% of patients had a stable vision. Only eight (13%) patients had postoperative focal deficits. Ten percent of patients had new-onset anosmia. The average Karnofsky score was improved. Only two patients had recurrence during follow-up. Conclusion  A unilateral pterional craniotomy is a versatile approach for the excision of anterior midline skull base meningioma, even for the larger lesions. The ability of this approach in the visualization of posterior neurovascular structures at the earlier stages of surgery while avoiding the opposite frontal lobe retraction and frontal sinus opening makes this approach more preferable over the other approaches.

The Party Wall: Redefining the Indications of Transcranial Approaches for Giant Pituitary Adenomas in Endoscopic Era

The evolution of endoscopic trans-sphenoidal surgery raises the question of the role of transcranial surgery for pituitary tumors, particularly with the effectiveness of adjunct irradiation. This narrative review aims to redefine the current indications for the transcranial approaches for giant pituitary adenomas in the endoscopic era. A critical appraisal of the personal series of the senior author (O.A.-M.) was performed to characterize the patient factors and the tumor's pathological anatomy features that endorse a cranial approach. Traditional indications for transcranial approaches include the absent pneumatization of the sphenoid sinus; kissing/ectatic internal carotid arteries; reduced dimensions of the sella; lateral invasion of the cavernous sinus lateral to the carotid artery; dumbbell-shaped tumors caused by severe diaphragm constriction; fibrous/calcified tumor consistency; wide supra-, para-, and retrosellar extension; arterial encasement; brain invasion; coexisting cerebral aneurysms; and separate coexisting pathologies of the sphenoid sinus, especially infections. Residual/recurrent tumors and postoperative pituitary apoplexy after trans-sphenoidal surgery require individualized considerations. Transcranial approaches still have a critical role in giant and complex pituitary adenomas with wide intracranial extension, brain parenchymal involvement, and the encasement of neurovascular structures.

Keyhole Approach for Clipping Anterior Circulation Aneurysms: Clinical Outcomes and Technical Note

Purpose: Keyhole craniotomy is a minimally invasive approach for the treatment of anterior circulation aneurysm. In this study, we evaluated the benefits and value of the keyhole approach by analyzing the surgical results in 235 patients with anterior circulation aneurysm treated by the keyhole approach and identifying lessons learned from addressing various complications in this approach.

Patients and Methods: This was a retrospective study in a single institution of 235 surgical patients with 248 anterior circulation aneurysms who had the supraorbital keyhole approach (SKA) or pterional keyhole approach (PKA) between January 2016 and January 2021. The modified Rankin Scale (mRS) was used to measure long-term results during follow up.

Results: All 235 patients' aneurysms were fully clamped and have not recurred. Among them, 31 (13.2%) had intraoperative aneurysm rupture, 8 (3.4%) had cerebral vascular spasm, and 4 (1.7%) had intraoperative brain edema. There were seven (3.0%) cases of postoperative infection, eight (3.4%) cases of postoperative cerebral infarction, one (0.4%) case of postoperative hematoma, and two (0.8%) patients had some form of cognitive impairment after surgery. Follow up after surgery demonstrated that 189 out of the 235 patients (80.4%) had favorable outcomes (mRS score 0–2), and 43 (18.3%) had poor outcomes (mRS from 3–5). There were three deaths (1.28%).

Conclusions: The keyhole approach has a quick postoperative recovery, a mild postoperative response, and a good surgical outcome. Our findings indicate that the keyhole approach is a safe and effective surgical method for the treatment of anterior circulation aneurysm.

Microsurgical Anatomy of the Anterior Circulation of the Brain Adjusted to the Neurosurgeon's Daily Practice

The study of cerebrovascular anatomy can be difficult and may take time due to its intrinsic complexity. However, it can also be difficult for the following reasons: the excessive description of neuroanatomy making articles hard to read, the unclear clinical application of what is written, the use of simplified or intricate schematic drawings that are not always appropriate for effective teaching, the poor quality of neuroanatomy dissections and the use of unusual views of figures that are not strictly related to the most frequent neuroimages to be interpreted in daily practice. Because of this, we designed an article that incorporates original and accurate anatomical dissections in an attempt to improve its comprehensibility. Five formalin-fixed adult cadaveric heads, whose vessels were injected with a colored silicone mixture (red for arteries and blue for veins), were dissected and examined under a microscope with magnifications from 3× to 40×. Special emphasis has been placed on correlating topographic anatomy with routine neuroimaging studies from computed tomographic angiography (CTA) and digital subtraction angiography (DSA). The essential surgical anatomy in a neurosurgeon’s daily practice is also described. The cadaveric dissections included in this study contribute to the understanding of the cerebrovascular anatomy necessary for the neurosurgeon’s daily practice.

Pterional Approach

The pterional approach is a workhorse in neurosurgery, to the point where perfect knowledge of its execution is essential in neurosurgical daily practice. The pterional transsylvian corridor is used to treat aneurysms involving anterior circulation, basilar apex, the proximal segment of the superior cerebellar and posterior cerebral artery, arteriovenous malformations and cavernous hemangiomas of the basal forebrain, anterior and middle skull base tumors, gliomas of the frontal, parietal, and temporal opercula, insula, mediobasal temporal region, cerebral peduncles, interpeduncular fossa, and also orbital lesions. We herein overview the core technique and variations of the pterional approach aimed at broadening surgical freedom and decreasing the risk of approach-related complications.

Pterional versus superciliary keyhole approach: direct comparison of approach-related complaints and satisfaction in the same patient

OBJECTIVE The objective of this study was to evaluate and compare the level of patient satisfaction and approach-related patient complaints between a superciliary keyhole approach and a pterional approach. METHODS Patients who underwent an ipsilateral superciliary keyhole approach and a contralateral pterional approach for bilateral intracranial aneurysms during an 11-year period were contacted and asked to complete a patient satisfaction questionnaire. The questionnaire covered 5 complaint areas related to the surgical approaches: craniotomy-related pain, sensory symptoms in the head, cosmetic complaints, palpable cranial irregularities, and limited mouth opening. The patients were asked to rate the 5 complaint areas on a scale from 0 (asymptomatic or very pleasant) to 4 (severely symptomatic or very unpleasant). Finally, the patients were asked to rate the level of overall satisfaction related to each surgical procedure on a visual analog scale (VAS) from 0 (most unsatisfactory) to 100 (most satisfactory). RESULTS A total of 21 patients completed the patient satisfaction questionnaire during a follow-up clinic visit. For the superciliary procedures, no craniotomy-related pain, palpable irregularities, or limited mouth opening was reported, and only minor sensory symptoms (numbness in the forehead) and cosmetic complaints (short linear operative scar) were reported (score = 1) by 1 (4.8%) and 3 patients (14.3%), respectively. Compared with the pterional approach, the superciliary approach showed better outcomes regarding the incidence of craniotomy-related pain, cosmetic complaints, and palpable irregularities, with a significant between-approach difference (p < 0.05). Furthermore, the VAS score for patient satisfaction was significantly higher for the superciliary approach (mean 95.2 ± 6.0 [SD], range 80-100) than for the pterional approach (mean 71.4 ± 10.6, range 50-90). Moreover, for the pterional approach, a multiple linear regression analysis indicated that the crucial factors decreasing the level of patient satisfaction were cosmetic complaints, craniotomy-related pain, and sensory symptoms, in order of importance (p < 0.05). CONCLUSIONS In successful cases in which the primary surgical goal of complete aneurysm clipping without postoperative complications is achieved, a superciliary keyhole approach provides a much higher level of patient satisfaction than a pterional approach, despite a facial wound. For a pterional approach, the patient satisfaction level is affected by the cosmetic results, craniotomy-related pain, and numbness behind the hairline, in order of importance.

Technical note: the use of frameless stereotactic guidance in the treatment of peripheral intracranial aneurysms

Frameless stereotactic guidance (FSG) has previously been reported to have advantages over intraoperative computed tomography (CT) and frame-based imaging guidance methods in the targeting of intracranial lesions. We report our experience using FSG to minimize brain dissection during microsurgical repair of peripheral aneurysms. We used FSG as a surgical adjunct in the management of 91 peripheral aneurysms. It was used to localise and avoid larger bridging veins, enabling us to minimise unnecessary brain dissection by coming directly down on the aneurysm dome in unruptured lesions or targeting the parent artery just proximal to the aneurysm in ruptured cases. We treated 72 aneurysms located on the distal ACA (79%), 7 on the PCA (7.7%), 6 on the MCA distal to the MCA bifurcation (6.6%), and 6 on the SCA (6.6%). There were no complications related to FSG use. However, we noted a tendency to create an overly limited corridor to the aneurysm, which did not allow sufficient proximal or distal control of the parent artery. In these cases, we had to widen our exposure by further opening the interhemispheric fissure to obtain more proximal control once the aneurysm was reached. Subsequently, we learned to avoid this problem by creating a slightly wider corridor during the initial exposure. Using FSG as a surgical adjunct for peripheral intracranial aneurysms allowed us to safely limit craniotomy size and brain dissection while more confidently exposing these unusually situated lesions, facilitating aneurysm clipping in our series.

Surgical Techniques and the Choice of Operative Approach for Cranioorbital Lesions

Objectives  Cranioorbital lesions present a great challenge for neurosurgeons and ophthalmologists. There is no consensus on the choice of surgical approach. The aims of this study were to investigate 49 cases of cranioorbital lesions and evaluate surgical approaches and outcomes. Patients and Methods  A retrospective study was done on 49 patients (51 operations) from 2009 to 2018. Information about the lesion was used to decide whether the supraorbital eyebrow approach (SEA) or pterional approach (PA) was performed. Results  Twenty-eight patients had surgical resection using SEA, 21 patients received PA, each group included one case of recurrence, who underwent reoperation via the same approach. SEA provided better cosmetic satisfaction, and a shorter incision than PA ( p  < 0.05). There was no significant difference in total resection rates, visual outcomes, recovery of ptosis, and other new surgical-related complications between SEA group and PA group ( p  > 0.05). Forty-nine cases of proptosis (94.1%, 49/51) were improved. Thirty-three patients (33/37, 89.2%) who underwent follow-up for longer than 12 weeks had a modified Rankin Scale (mRS) score ≤ 3. Conclusion  Surgery is the preferred treatment for cranioorbital lesions, but total resection is difficult. SEA may be a more minimally invasive option for some more limited lesions superior to optic nerve. PA may be more reasonable for the lesion with obvious hyperostosis and more extensive lesions.

Immersive Surgical Anatomy of the Pterional Approach

The pterional approach (PA) is a versatile anterolateral neurosurgical technique that enables access to reach different structures contained in the cranial fossae. It is essential for neurosurgical practice to dominate and be familiarized with its multilayer anatomy. Recent advances in three-dimensional (3D) technology can be combined with dissections to better understand the spatial relationships between anatomical landmarks and neurovascular structures that are encountered during the surgical procedure. The present study aims to create a stereoscopic collection of volumetric models (VM) obtained from cadaveric dissections that depict the relevant anatomy and surgical techniques of the PA. Five embalmed heads and two dry skulls were used to record and simulate the PA. Relevant steps and anatomy of the PA were recorded using 3D scanning technology (e.g. photogrammetry, structured light scanner) to construct high-resolution VM. Stereoscopic images, videos, and VM were generated to demonstrate major anatomical landmarks for PA. Modifications of the standard PA, including the mini-pterional and two-part pterional approaches, were also described. The PA was divided into seven major steps: positioning, incision of the skin, dissection of skin flap, dissection of temporal fascia, craniotomy, drilling of basal structures, and dural opening. Emphasis was placed on preserving the temporal branches of the facial nerve and carefully dissecting the temporalis muscle. The interactive models presented in this article allow for clear visualization of the surgical anatomy and windows in 360-degrees and VR. This new modality of recording neuroanatomical dissections renders a closer look at every nuance of the topography experienced by our team in the laboratory. By accurately depicting essential landmarks, stereoscopy and VM can be valuable resources for anatomical education and surgical planning.

[A comparative study of the efficacy and safety of the eyebrow supraorbital approach in cerebral aneurysm surgery]

OBJECTIVE

The study objective was to compare the efficacy and safety of supraorbital eyebrow (SEA) and pterional (PA) approaches in surgery of anterior circle of Willis (ACW) aneurysms and to determine the advantages and disadvantages of SEA in aneurysm clipping.

MATERIAL AND METHODS

The analysis included 166 patients with ACW aneurysms aged 18 to 70 years who were treated in the Neurosurgery Department of the Interregional Clinical Diagnostic Center (Kazan) in the period from 2013 to 2016. At the first stage of the study, factors affecting surgical outcomes were compared (by using the Glasgow outcome scale (GOS)) in subpopulations of patients operated on using SEA (n=49) and PA (n=117). At the second stage, we compared the efficacy and safety of approaches using a case-control subanalysis in appropriate subgroups of the SEA (n=37) and PA (n=37) groups. The subgroups were comparable in the following factors: gender, age, severity of subarachnoid hemorrhage (SAH) on (Fisher scale), severity of the patient's condition (Hunt-Hess scale), size and location of the aneurysm, surgery duration, intraoperative aneurysm rupture (IOAR), amount of blood loss, rate of frontal sinus surgery, rate of nasal CSF leak, rate of intraoperative and postoperative complications, hemorrhagic and ischemic complications according to postoperative CT, patient's satisfaction with the cosmetic result of surgery (visual analogue scale - VAS), and treatment outcomes (GOS). Treatment outcomes (GOS) and patient's satisfaction with the cosmetic result of surgery (VAS) were considered as the efficacy parameters. The safety parameters included the amount of blood loss, rate of frontal sinus surgery, rate of nasal CSF leak, and rate of intraoperative and postoperative (hemorrhagic and ischemic) complications.

RESULTS

At the first stage of the study, we found that the amount of intraoperative blood loss in the subpopulation of patients with ACW aneurysms who were operated on using SEA was statistically significantly less than that in the PA group (p=0.0000002). In the postoperative period, patients who underwent surgery using SEA less frequently experienced neurological deficit (p=0.003), less frequently developed first epileptic seizures (p=0.035), and had a lower rate of hemorrhagic complications (p=0.003) and better treatment outcomes (GOS) (p=0.01). Comparison of appropriate subgroups in the SEA and PA groups, which were selected according to the case-control methodology and were comparable in the main factors affecting treatment outcomes, confirmed statistically significantly lower blood loss for SEA (p=0.0000002) than for PA. Compared to the SEA group, the PA group was characterized by more frequent, but not statistically significantly different, IOAR (p=1), postoperative worsening of neurological deficit (p=0.115), newly developed epileptic seizures (p=0.493), and hemorrhagic complications (p=0.0557). There were no deaths in both groups. In the SEA group, the treatment outcome was scored 4 and 5 (GOS, favorable outcome); in the PA group, the treatment outcome was scored 3 (GOS) in 2 (5.4%) patients and 4 or 5 in 35 (94.6%) patients (p=0.063). The mean subjective score of satisfaction with the treatment result (VAS) in the SEA group was significantly higher (9.4±1) than in the PA group (8.8±1; p=0.01).

CONCLUSION

SEA is an adequate approach for clipping ACW aneurysms, in particular ACA-AComA and MCA aneurysms, which is as effective and safe as the pterional approach.

A difficult-to-treat Acom aneurysm with the combined vascular anomaly of Acom fenestration and accessory anterior cerebral artery

Background:

Vascular anomaly and aneurysmal formation of an anterior communicating artery (Acom) complex has often been reported. Because of such a complicated relationship between the vascular structure and aneurysms, Acom aneurysm is one of the most difficult aneurysms to treat among other common anterior circulation aneurysms. We experienced an extremely rare and difficult-to-treat case of ruptured Acom aneurysm with the combined vascular anomaly of the Acom fenestration and an accessory anterior cerebral artery (ACA).

Case Description:

A 29-year-old man underwent a clipping surgery for a ruptured Acom aneurysm with an Acom fenestration and an accessory ACA. By reasons of the complicated Acom structure and a posteriorly-projecting aneurysm, the patient was operated via an interhemispheric approach, which is generally reported to provide the best operative view for all types of Acom aneurysms. However, we could not help applying a clip in the narrow working space and the limited operative view, due to the poor mobilization of Acom complex and the interruption by an accessory ACA.

Conclusion:

The interhemispheric approach may exceptionally have a blind area behind the Acom complex in the case of Acom aneurysms with an accessory ACA. Additionally, the aneurysms arising from the Acom fenestration strongly require neurosurgeons to take a more accurate surgical approach to obtain a direct visualization for an aneurysmal neck.

Combined Interhemispheric and Transsylvian Approach for Resection of Craniopharyngioma

We present a 37-year-old male case of cystic suprasellar huge craniopharyngioma, who presented with significant memory disturbance due to obstructive hydrocephalus. Combined interhemispheric and pterional approach was chosen to resect huge suprasellar tumor. Interhemispheric trans-lamina terminalis approach was quite effective to resect third ventricular tumor, while pterional approach was useful to dissect tumor out of basilar perforators and stalk.

The link to the video can be found at: https://youtu.be/BoYIPa96kdo .

Microsurgical Resection of Tuberculum Sellae Meningioma via Pterional Craniotomy with Extradural Anterior Clinoidectomy and Optic Unroofing

Microsurgical treatment of suprasellar tumors, in particular tuberculum sellae meningiomas, poses significant challenge. These tumors are surrounded by vital neurovascular structures, such as optic apparatus, pituitary stalk, internal carotid artery and its branches, and anterior cerebral arteries. In large and complex cases, early identification and decompression of these structures may facilitate safer dissection and resection. Therefore, extradural anterior clinoidectomy with optic unroofing facilitates the internal carotid artery exposure and optic nerve decompression. In this video, we describe a 37-year-old female patient who presented with new onset of severe headaches. On visual examination, she was found to have bitemporal visual defects. MRI scan of the head showed a large, approximately 3 cm suprasellar tumor consistent with tuberculum sellae meningioma. She underwent surgical resection via pterional craniotomy with extradural anterior clinoidectomy and optic unroofing. Microsurgical gross total resection was achieved and histopathology was WHO grade II meningioma. She had an uneventful postoperative course and visual field examination improved significantly. In this video, surgical technique in performing extradural anterior clinoidectomy and optic unroofing and steps of microsurgical resection are demonstrated. The link to the video can be found at: https://youtu.be/oPZ8NTyvxJc .

Tuberculum Sellae Meningioma Resection: Technical Nuances on the Frontopterional Approach

Tuberculum sellae meningioma remains a surgical challenge. Deep location of tumor, vascular and nerve encasement, and pituitary stalk involvement are the main technical issues. The frontopterional approach represents a natural, simple, and elegant approach to this area enabling surgeon to have a direct control on all anatomical structures. A 42-year-old woman was referred with a delayed diagnosis of tuberculum sellae meningioma due to the presence of HLA-B27-associated uveitis. She presented with 1/10 visual acuity in the left eye and no right visual function. A left frontopterional craniotomy was performed. Visual function improved postoperatively. The video illustrates the cisternal anatomy via pterional approach. The link to the video can be found at: https://youtu.be/Hmbf5bt7A64 .

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 İzmir 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.

Combined interhemispheric translamina terminalis and pterional approach for a dorsum sellae meningioma

This video demonstrates a surgical technique of resecting dorsum sellae meningioma using a combined interhemispheric translamina terminalis approach and pterional approach with clinoidectomy. The tumor, 5 cm in maximum diameter, originated from the dorsum sellae, compressed the third ventricle and the midbrain, and displaced the pituitary stalk ventrally. Feeding arteries of the tumor were bilateral meningohypophyseal trunks, mainly from the right side. The authors performed devascularization of the tumor via a right pterional approach following frontotemporal craniotomy, and debulking of the tumor via an interhemispheric translamina terminalis approach following bifrontal craniotomy. These procedures with two separate craniotomies enabled safe and effective resection of the tumor. The video can be found here: https://youtu.be/DEnKOC5zQ_M .

Interdural cavernous sinus dermoid cyst in a child: case report

Interdural dermoid cysts (DCs) of the cavernous sinus (CS), located between the outer (dural) and inner layer (membranous) of the CS lateral wall, are rare lesions in children. The authors report on a 5-year-old boy with third cranial nerve palsy and exophthalmos who underwent gross-total removal of an interdural DC of the right CS via a frontotemporal approach. The patient had a good outcome and no recurrence at the 12-month follow-up. To the best of the authors' knowledge this is the second pediatric case of interdural DC described in the literature.

Quantitative and qualitative analysis of the working area obtained by endoscope and microscope in pterional and orbitozigomatic approach to the basilar artery bifurcation using computed tomography based frameless stereotaxy: A cadaver study

OBJECTIVE

Basilar aneurisms are one of the most complex and challenging pathologies for neurosurgeons to treat. Endoscopy is a recently rediscovered neurosurgical technique that could lend itself well to overcome some of the vascular visualization challenges associated with this pathology. The purpose of this study was to quantify and compare the basilar artery (BA) bifurcation (tip of the basilar) working area afforded by the microscope and the endoscope using different approaches and image guidance.

MATERIALS AND METHODS

We performed a total of 9 dissections, including pterional (PT) and orbitozygomatic (OZ) approaches bilaterally in five whole, fresh cadaver heads. We used computed tomography based image guidance for intraoperative navigation as well as for quantitative measurements. We estimated the working area of the tip of the basilar, using both a rigid endoscope and an operating microscope. Operability was qualitatively assessed by the senior authors.

RESULTS

In microscopic exposure, the OZ approach provided greater working area (160 ± 34.3 mm(2)) compared to the PT approach (129.8 ± 37.6 mm(2)) (P > 0.05). The working area in both PT and OZ approaches using 0° and 30° endoscopes was larger than the one available using the microscope alone (P < 0.05). In the PT approach, both 0° and 30° endoscopes provided a working area greater than a microscopic OZ approach (P < 0.05) and an area comparable to the OZ endoscopic approach (P > 0.05).

CONCLUSION

Integration of endoscope and microscope in both PT and OZ approaches can provide significantly greater surgical exposure of the BA bifurcation compared to that afforded by the conventional approaches alone.

Combined interhemispheric and pterional approach for ACOM and left MCA aneurysms

This video demonstrates combined two separate craniotomies for two difficult unruptured cerebral aneurysms. The anterior communicating artery (ACOM) aneurysm existed at a high position, projected posteriorly, and thus necessitated an interhemispheric approach. Left middle cerebral artery (MCA) aneurysm with complex figure was treated through a separate pterional approach. Meticulous micro-cisternal opening under high magnification enabled safe and effective exposure of both aneurysms with minimal brain retraction, which alleviated brain damage as shown in postoperative images. The video can be found here: http://youtu.be/mBYsaAVekCA .

Awake craniotomy for trapping a giant fusiform aneurysm of the middle cerebral artery

BACKGROUND

Giant fusiform aneurysms of the distal middle cerebral artery (MCA) are rare lesions that, because of the absence of an aneurysm neck and the presence of calcified walls and partial thrombosis, can be difficult to clip without sacrificing the parent vessel. Moreover, when the aneurysm is located in the dominant hemisphere, it is not possible to test language and cognitive functions during surgical intervention, making the closure of the parent vessel extremely dangerous.

CASE DESCRIPTION

A 46-year-old woman presented with a one-year history of frontal headache without neurological deficit. A magnetic resonance imaging and an angiography showed a giant fusiform aneurysm of the left M2 tract. Because of the location and the absence of a neck, the aneurysm was considered difficult to coil and not amenable to preoperative balloon occlusion; thus, the patient was a candidate for surgical treatment. After a preoperative psychological evaluation, patient underwent awake craniotomy with the asleep-awake-asleep technique. A standard left pterional approach was performed to expose the internal carotid artery, the MCA and the aneurysm originating from the frontal branch of the MCA. Neurological examination responses remained unchanged during temporary parent artery occlusion, and trapping was successfully performed.

CONCLUSIONS

Awake craniotomy is a useful option in intracranial aneurysm surgery because it permits neurological testing before vessels are permanently clipped or sacrificed. With the asleep-awake-asleep technique, it is possible to perform a standard pterional craniotomy, which allows good exposure of the vascular structures without cerebral retraction.

The Role of the Pterional Approach in the Surgical Treatment of Olfactory Groove Meningiomas: A 20-year Experience

Background Olfactory groove meningiomas remain surgically challenging. The common microsurgical approaches suffer from late exposure of the neurovascular structures. Conversely, the pterional approach has the advantage of early dissection of the posterior neurovascular complex. Methods We reviewed the records of patients treated for olfactory groove meningioma in our department between 1991 and 2010. A total of 61 patients underwent removal of olfactory groove meningiomas via the pterional approach. These included 58 primary and 3 recurrent tumors. Mean overall follow-up time was 122 months. Results Early exposure and dissection of the internal carotid artery, middle cerebral artery, anterior cerebral artery, and optic nerve was feasible in all cases. Complete tumor removal was achieved in 60 patients. Morbidity and mortality rates were 26% and 1.6% respectively. Postoperative complications included epileptic seizures (five patients) and cerebrospinal fluid (CSF) leak (two patients). During follow-up, we recorded three tumor recurrences. Conclusions The pterional approach appears to be an excellent solution for the treatment of olfactory groove meningiomas. Its foremost advantage is early visualization of the posterior neurovascular complex. Moreover, it allows frontal sinus preservation and timely tumor devascularization and avoids excessive brain retraction. The pterional view is familiar to most neurosurgeons and therefore the transition to this technique is fairly straightforward.

Accessing the basilar artery apex: is the temporopolar transcavernous route an anatomically advantageous alternative?

The restricted operative field, difficulty of obtaining proximal vascular control, and close relationship to important anatomic structures limit approaches to basilar apex aneurysms. We used a cadaveric model to compare three surgical transcavernous routes to the basilar apex in the neutral configuration. Five cadaveric heads were dissected and analyzed. Working areas and length of exposure provided by the transcavernous (TC) approach via pterional, orbitozygomatic, and temporopolar (TP) routes were measured along with assessment of anatomic variation for the basilar apex region. In the pterional TC and orbitozygomatic TC approaches, the mean length of exposure of the basilar artery measured 6.9 and 7.2 mm, respectively (p = NS). The mean length of exposure in a TP TC approach increased to 9.3 mm (p < 0.05). Compared with the pterional and orbitozygomatic approaches, the TP TC approach provided a larger peribasilar area of exposure ipsilaterally and contralaterally (p < 0.05). The multiplanar working area related to the TP TC approach was 77.7 and 69.5% wider than for the pterional TC and orbitozygomatic TC, respectively. For a basilar apex in the neutral position, the TP TC approach may be advantageous, providing a wider working area for the basilar apex region, improving maneuverability for clip application, fine visualization of perforators, and better proximal control.

Pterional approach versus unilateral frontal approach on tuberculum sellae meningioma: Single centre experiences

INTRODUCTION

Tuberculum Sellae Meningioma is one of the most challenging surgeries among neurosurgeons. Many approaches have been established in the effort of removing the tumor and some of them are supported by an advanced neurosurgical technology. In this study, we aim to compare the efficacy of the two most common approaches, the pterional and the unilateral frontal.

MATERIALS AND METHODS

This was a restrospective study that aimed to observe the efficacy of the two most common approaches used in our center, the pterional and the unilateral frontal, in resecting the tuberculum sellae meningioma, which was held in Dr. Hasan Sadikin General Hospital, Bandung, from July 2007-July 2010. Twenty patients were enrolled with half of them operated by the pterional approach and the rest by unilateral frontal approach. We evaluated six parameters: tumor size, degree of tumor removal, surgery duration, post-operative cerebral edema, patients' outcome, and length of stay, which were evaluated to take measure of the efficacy of each procedure.

RESULTS

We found that the pterional approach gave more advantages than the unilateral frontal. Total tumor removal, especially in tumor size ≥ 3 cm was achieved in a greater number of subjects in the pterional (P<0.023). Other advantages of the pterional compared to the unilateral frontal were a shorter surgical duration (P=0.024), shorter length of stay (P=0.009) and less frequency of post-operative cerebral edema incidence (P=0.023).

CONCLUSION

According to our facilities and conditions, it seems that the pterional approach have more advantages than the unilateral frontal approach in tuberculum sellae meningioma surgery.

Successful resection of the recurrence of a cavernous malformation of the optic chiasm

The case of a 33-year-old female who suffered from a recurrence of an intrachiasmatic cavernous malformation is presented. She had already undergone surgery in 1991 and 2001 and was admitted to our hospital with reduced vision in the right eye. After MRI, and diagnosis of recurrence of the cavernoma, a neurosurgical operation was performed using the pterional approach. The intraoperative situation was documented with micro photographs. The postoperative course was uneventful. The female described a minimal improvement of her vision. No postoperative complications were observed. To our knowledge, microsurgically complete extirpation of a recurrence of an intrachiasmatic cavernoma has not yet been reported in the literature.