Combined Petrosal Intertentorial Approach: A Cadaveric Study of Comparison With the Standard Combined Petrosectomy.

BACKGROUND AND OBJECTIVES: The combined petrosal intertentorial approach (CPIA) has been proposed as an alternative to standard combined petrosal approach (SCPA). CPIA has been designed to maintain integrity of the temporal dura with a view to reduce temporal lobe morbidity and venous complications. This study has been designed to perform a quantitative comparison between these approaches. METHODS: Five human specimens were used for this study. CPIA was performed on one side and SCPA on the opposite side. The area of exposure (petroclival and brainstem), surgical freedom, and angles of attack to a predefined target were measured and compared. RESULTS: SCPA provided a significantly larger petroclival area of exposure (6.81 ± 0.60 cm2) over the CPIA (5.59 ± 0.59 cm2), P = .012. The area of brainstem exposed with SCPA was greater than with CPIA (7.17 ± 0.84 vs 5.63 ± 0.72, P = .014). The area of surgical freedom was greater in SCPA rather than in CPIA (8.59 ± 0.55 and 7.13 ± 0.96 cm2, respectively, P = .019). There was no significative difference between CPIA and SCPA in the vertical angles of attack for the Meckel cave, Dorello canal, and root entry zone of cranial nerve VII. Conversely, the horizontal angles of attack permitted by the CPIA were significantly smaller for the Meckel cave (52.36° ± 5.01° vs 64.4° ± 5.3°, P = .006) and root entry zone of cranial nerve VII (30.7° ± 4.4° vs 40.1° ± 6.2°, P = .025). CONCLUSION: CPIA is associated with a reduction in terms of the area of surgical freedom (22%), skull base (18%), brainstem exposure (17%), and horizontal angles of attack (18%-23%) when compared with SCPA. This loss in terms of exposure is counterbalanced by the advantage of keeping the temporal lobe covered by an extra layer of meningeal tissue, thus possibly reducing the risk of temporal lobe injury and venous infarction. These results need to be validated with adequate clinical experience.

Cisternal nicardipine for prevention of delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage: a comparative retrospective cohort study.

PURPOSE: Intrathecal vasoactive drugs have been proposed in patients with aneurysmal subarachnoid hemorrhage (aSAH) to manage cerebral vasospasm (CV). We analyzed the efficacy of intracisternal nicardipine compared to intraventricular administration to a control group (CG) to determine its impact on delayed cerebral ischemia (DCI) and functional outcomes. Secondary outcomes included the need for intra-arterial angioplasties and the safety profile. METHODS: We performed a retrospective analysis of prospectively collected data of all adult patients admitted for a high modified Fisher grade aSAH between January 2015 and April 2022. All patients with significant radiological CV were included. Three groups of patients were defined based on the CV management: cisternal nicardipine (CN), ventricular nicardipine (VN), and no intrathecal nicardipine (control group). RESULTS: Seventy patients met the inclusion criteria. Eleven patients received intracisternal nicardipine, 18 intraventricular nicardipine, and 41 belonged to the control group. No cases of DCI were observed in the CN group (p = 0.02). Patients with intracisternal nicardipine had a reduced number of intra-arterial angioplasties when compared to the control group (p = 0.03). The safety profile analysis showed no difference in complications across the three groups. Intrathecal (ventricular or cisternal) nicardipine therapy improved functional outcomes at 6 months (p = 0.04) when compared to the control group. CONCLUSION: Administration of intrathecal nicardipine for moderate to severe CV reduces the rate of DCI and improved long-term functional outcomes in patients with high modified Fisher grade aSAH. This study also showed a relative benefit of cisternal over intraventricular nicardipine, thereby reducing the number of angioplasties performed in the post-treatment phase. However, these preliminary results should be confirmed with future prospective studies.

Anterior Petrosectomy With Intertentorial Approach.

BACKGROUND AND OBJECTIVES: The extradural anterior petrosal approach (EAPA) can present a challenge because it deals with critical structures in a narrow, confined corridor. It is associated with several potential approach-related risks including temporal lobe and venous injuries. Tentorial peeling has the potential to largely eliminate these risks during the approach and may offer more options for tailoring the dural opening to the anatomic region that one wants to expose. METHODS: Anatomic dissections of five adult injected non-formalin-fixed cadaveric heads were performed. Anterior petrosectomy with intertentorial approach (APIA) through a tentorial peeling was completed. Step-by-step documentation of the cadaveric dissections and diagrammatic representations are presented along with an illustrative case. RESULTS: Tentorial peeling separates the tentorium into a temporal tentorial leaf and posterior fossa tentorial leaf, adding a fourth dural layer to the three classic ones described during a standard EAPA. This opens out the intertentorial space and offers more options for tailoring the dural incisions specific to the pathology being treated. This represents a unique possibility to address brainstem or skull base pathology along the mid- and upper clivus with the ability to keep the entire temporal lobe and basal temporal veins covered by the temporal tentorial leaf. The APIA was successfully used for the resection of a large clival chordoma in the illustrative case. CONCLUSION: APIA is an interesting modification to the classic EAPA to reduce the approach-related morbidity. The risk reduction achieved is by eliminating the exposure of the temporal lobe while maintaining the excellent access to the petroclival region. It also provides several options to tailor the durotomies based on the localization of the lesion.

Surgical morbidity of the extradural anterior petrosal approach: the Lariboisière experience.

OBJECTIVE: Concerns about the approach-related morbidity of the extradural anterior petrosal approach (EAPA) have been raised, especially regarding temporal lobe and venous injuries, hearing impairment, facial nerve palsy, cerebrospinal fluid fistula, and seizures. There is lack in the literature of studies with detailed analysis of surgical complications. The authors have presented a large series of patients who were treated with EAPA, focusing on complications and their avoidance. METHODS: The authors carried out a retrospective review of patients who underwent EAPA at their institution between 2012 and 2021. They collected preoperative clinical characteristics, operative reports, operative videos, findings on neuroimaging, histological diagnosis, postoperative course, and clinical status at last follow-up. For pathologies without petrous bone invasion, the amount of petrous apex drilling was calculated and classified as low (< 70% of the volume) or high (≥ 70%). Complications were dichotomized as approach related and resection related. RESULTS: This study included 49 patients: 26 with meningiomas, 10 brainstem cavernomas, 4 chondrosarcomas, 4 chordomas, 2 schwannomas, 1 epidermoid cyst, 1 cholesterol granuloma, and 1 osteoblastoma. The most common approach-related complications were temporal lobe injury (6.1% of patients), seizures (6.1%), pseudomeningocele (6.1%), hearing impairment (4.1%), and dry eye (4.1%). Approach-related complications occurred most commonly in patients with a meningioma (p = 0.02) and Meckel's cave invasion (p = 0.02). Gross-total or near-total resection was correlated with a higher rate of tumor resection-related complications (p = 0.02) but not approach-related complications (p = 0.76). Inferior, lateral, and superior tumoral extension were not correlated with a higher rate of tumor resection-related complications. No correlation was found between high amount of petrous bone drilling and approach- or resection-related complications. CONCLUSIONS: EAPA is a challenging approach that deals with critical neurovascular structures and demands specific skills to be safely performed. Contrary to general belief, its approach-related morbidity seems to be acceptable at dedicated skull base centers. Morbidity can be lowered with careful examination of the preoperative neuroradiological workup, appropriate patient selection, and attention to technical details.

Endovascular treatment of pediatric basilar artery aneurysms: case series and literature review.

PURPOSE: Pediatric basilar artery aneurysms are rare and challenging to treat. Microsurgical options and standard endovascular coiling are often undesirable choices for treatment of this pathology. Additional endovascular strategies are needed. METHODS: Presentation, diagnosis, and management of pediatric basilar aneurysms were reviewed, with an emphasis on endovascular treatment strategies. Our case series of 2 patients was presented in detail, one treated with flow diversion and vessel sacrifice and one treated with stent-assisted coiling. An extensive review of the literation was performed to find other examples of pediatric basilar artery aneurysms treated with endovascular techniques. RESULTS: Twenty-nine studies met inclusion criteria. Fifty-nine aneurysms in 58 patients were treated using endovascular techniques. Mortality rate was 10.3% (6/58) and a poor outcome (GOS 1-3) occurred in 15.5% (9/58). There were 4 reported recurrences requiring retreatment; however, only 46.5% of patients had reported follow-up of at least 1 year. 71.1% (42/59) were dissecting aneurysms. CONCLUSION: Basilar artery aneurysms in the pediatric population are rare, commonly giant and fusiform, and often not amenable to microsurgical or coiling techniques. The surrounding vasculature, location, size, and morphology of the aneurysm along with the durability of treatment must be considered in treatment decisions. With proper patient selection, stent-assisted coiling and flow diversion may increase the durability and safety of endovascular treatment in this population.

Surgical management of giant pituitary neuroendocrine tumors: Meta-analysis and consensus statement on behalf of the EANS skull base section.

Introduction: The optimal surgical treatment for giant pituitary neuroendocrine tumors(GPitNETs) is debated. Research question: The aim of this paper is to optimize the surgical management of these patients and to provide a consensus statement on behalf of the EANS Skull Base Section. Material and methods: We constituted a task force belonging to the EANS skull base committee to define some principles for the management of GPitNETs. A systematic review was performed according to PRISMA guidelines to perform a meta-analysis on surgical series of GPitNETs. Weighted summary rates were obtained for the pooled extent of resection and according to the surgical technique. These data were discussed to obtain recommendations after evaluation of the selected articles and discussion among the experts. Results: 20articles were included in our meta-analysis, for a total of 1263 patients. The endoscopic endonasal technique was used in 40.3% of cases, the microscopic endonasal approach in 34% of cases, transcranial approaches in 18.7% and combined approaches in 7% of cases. No difference in terms of gross total resection (GTR) rate was observed among the different techniques. Pooled GTR rate was 36.6%, while a near total resection (NTR) was possible in 45.2% of cases. Cavernous sinus invasion was associated with a lower GTR rate (OR: 0.061). After surgery, 35% of patients had endocrinological improvement and 75.6% had visual improvement. Recurrent tumors were reported in 10% of cases. Discussion and conclusion: After formal discussion in the working group, we recommend the treatment of G-PitNETs tumors with a more complex and multilobular structure in tertiary care centers. The endoscopic endonasal approach is the first option of treatment and extended approaches should be planned according to extension, morphology and consistency of the lesion. Transcranial approaches play a role in selected cases, with a multicompartmental morphology, subarachnoid invasion and extension lateral to the internal carotid artery and in the management of residual tumor apoplexy.

Eyebrow incision with a crescent-shaped orbital rim craniotomy for microscopic and endoscopic transorbital approach to the anterior and middle cranial fossa: A cadaveric study and case presentation.

•The transorbital approach combining eyebrow incision and crescent-shaped craniotomy increases the surgical freedom to access the anterior and middle skull-base.•The technic allows the use of both endoscope and microscope.•The concept is at the crossroad between the supraorbital keyhole and endoscopic trans-orbital approach.

Management strategies in clival and craniovertebral junction chordomas: a 29-year experience.

OBJECTIVE: Chordomas represent one of the most challenging subsets of skull base and craniovertebral junction (CVJ) tumors to treat. Despite extensive resection followed by proton-beam radiation therapy, the recurrence rate remains high, highlighting the importance of developing efficient treatment strategies. In this study, the authors present their experience in treating clival and CVJ chordomas over a 29-year period. METHODS: The authors conducted a retrospective study of clival and CVJ chordomas that were surgically treated at their institution from 1991 to 2020. This study focuses on three aspects of the management of these tumors: the factors influencing the extent of resection (EOR), the predictors of survival, and the outcomes of the endoscopic endonasal approaches (EEAs) compared with open approaches (OAs). RESULTS: A total of 265 surgical procedures were performed in 210 patients, including 123 OAs (46.4%) and 142 EEAs (53.6%). Tumors that had an intradural extension (p = 0.03), brainstem contact (p = 0.005), cavernous sinus extension (p = 0.004), major artery encasement (p = 0.01), petrous apex extension (p = 0.003), or high volume (p = 0.0003) were significantly associated with a lower EOR. The 5-year progression-free survival (PFS) and overall survival (OS) rates were 52.1% and 75.1%, respectively. Gross-total resection and Ki-67 labeling index < 6% were considered to be independent prognostic factors of longer PFS (p = 0.0005 and p = 0.003, respectively) and OS (p = 0.02 and p = 0.03, respectively). Postoperative radiation therapy correlated independently with a longer PFS (p = 0.006). Previous surgical treatment was associated with a lower EOR (p = 0.01) and a higher rate of CSF leakage after EEAs (p = 0.02) but did not have significantly lower PFS and OS compared with primary surgery. Previously radiation therapy correlated with a worse outcome, with lower PFS and OS (p = 0.001 and p = 0.007, respectively). EEAs were more frequently used in patients with upper and middle clival tumors (p = 0.002 and p < 0.0001, respectively), had a better rate of EOR (p = 0.003), and had a lower risk of de novo neurological deficit (p < 0.0001) compared with OAs. The overall rate of postoperative CSF leakage after EEAs was 14.8%. CONCLUSIONS: This large study showed that gross-total resection should be attempted in a multidisciplinary skull base center before providing radiation therapy. EEAs should be considered as the gold-standard approach for upper/middle clival lesions based on the satisfactory surgical outcome, but OAs remain important tools for large complex chordomas.

Combined petrosal approach for resection of a large left petroclival meningioma.

Petroclival meningiomas represent the most complex lesions in skull base surgery, being closely related to critical neurovascular structures. The combined petrosal approach allows a wide exposure of the petroclival region and provides multiple angles of attack, limiting brain retraction. The authors present the case of a 54-year-old man with a large left petroclival meningioma responsible for headaches, dysphagia, and trigeminal neuralgia. The lesion was resected using a combined petrosal approach. A progressive improvement of the preoperative symptoms was observed. Postoperative MRI showed a near-total resection of the tumor, along with reexpansion of the brainstem. The video can be found here: https://stream.cadmore.media/r10.3171/2022.1.FOCVID21226.

External Validation of the HATCH (Hemorrhage, Age, Treatment, Clinical State, Hydrocephalus) Score for Prediction of Functional Outcome After Subarachnoid Hemorrhage.

BACKGROUND: The Hemorrhage, Age, Treatment, Clinical State, Hydrocephalus (HATCH) Score has previously shown to predict functional outcome in aneurysmal subarachnoid hemorrhage (aSAH). OBJECTIVE: To validate the HATCH score. METHODS: This is a pooled cohort study including prospective collected data on 761 patients with aSAH from 4 different hospitals. The HATCH score for prediction of functional outcome was validated using calibration and discrimination analysis (area under the curve). HATCH score model performance was compared with the World Federation of Neurosurgical Societies and Barrow Neurological Institute score. RESULTS: At the follow-up of at least 6 months, favorable (Glasgow Outcome Score 4-5) and unfavorable functional outcomes (Glasgow Outcome Score 1-3) were observed in 512 (73%) and 189 (27%) patients, respectively. A higher HATCH score was associated with an increased risk of unfavorable outcome with a score of 1 showing a risk of 1.3% and a score of 12 yielding a risk of 67%. External validation showed a calibration intercept of -0.07 and slope of 0.60 with a Brier score of 0.157 indicating good model calibration and accuracy. With an area under the curve of 0.81 (95% CI 0.77-0.84), the HATCH score demonstrated superior discriminative ability to detect favorable outcome at follow-up compared with the World Federation of Neurosurgical Societies and Barrow Neurological Institute score with 0.72 (95% CI 0.67-0.75) and 0.63 (95% CI 0.59-0.68), respectively. CONCLUSION: This multicenter external validation analysis confirms the HATCH score to be a strong independent predictor for functional outcome. Its incorporation into daily practice may be of benefit for goal-directed patient care in aSAH.

Endoscopic-Assisted Microsurgical Resection of Right Recurrent Meckel's Cave Meningioma Extended to Cavernous Sinus.

Objective This study was aimed to present the complete removal of a large recurrent Meckel's cave meningioma. Design This study is a case report. Setting The study was conducted at Department of Neurosurgery and Skull Base Laboratory at Lariboisiére Hospital, Paris. Participant A 53-year-old male was presented with a severe V1, V2, and V3 hypoesthesia and pain. He was operated 7 years ago for a right Meckel's cave meningioma with postoperative V1-V2 hypoesthesia. Magnetic resonance imaging (MRI) showed a large tumor recurrence extending into the cavernous sinus (CS), posterior fossa (PF), sphenoid sinus (SS), pterygopalatine (PPF), and infratemporal fossa (ITF; Fig. 1 ). Main Outcome Measures Radiological results and postoperative course were assessed for this study. Results The previous right frontotemporal approach was used. The lateral wall of the orbit, the middle fossa floor and the anterior temporal base were drilled to expose the orbit, PPF, and ITF. Foramen ovale (FO), foramen rotondum (FR), and superior orbital fissure (SOF) were opened. The meningoorbital band was cut and the lateral wall of CS was elevated ( Fig. 2 ). The inferior orbital fissure was opened and tumor removed into the ITF, PPF, and orbit. After entering Meckel's cave from above, tumor was removed from PF. After microsurgical tumor removal, a 45-degree endoscope was used to remove tumor remnant and mucosa into SS. A watertight dural closure with pericranium was performed, reinforced with autologous fat and fibrin glue. Postoperative MRI showed complete tumor resection ( Fig. 1 ). The patient experienced a right-side keratitis that resolved within 10 days and a V3 hypoesthesia that improved at 2 months. Conclusion This surgical case shows how the anatomical knowledge is mandatory in skull base surgery and how the integration of microsurgical and endoscopic-assisted techniques allows to obtain optimal results. The link to the video can be found at: https://youtu.be/qxt_389AdWU .

Tentorial peeling during combined petrosal approach: a cadaveric dissection.

BACKGROUND: The combined petrosal approach is an excellent method to access the petroclival region but has the inherent risk of injury to the temporal lobe and Vein of Labbé. Tentorial peeling has the potential to largely eliminate these risks during the classic combined transpetrosal approach. METHODS: Anatomical dissection of three adult injected non-formalin fixed cadaveric heads was performed. Combined petrosal approach with tentorial peeling was completed. A tentorial incision just superior and parallel to the superior petrosal sinus was made to enable peeling of the tentorium into two layers, the posterior fossa tentorial leaf (PFTL), and the temporal tentorial leaf (TTL). RESULTS: Tentorial peeling clearly exposed the continuity between the temporal dura and the TTL as well as the continuity between the presigmoid dura and the PFTL. This enabled the creation of a large dural flap extending to the tentorial incisura, providing wide access to the petroclival region without any exposure of the temporal lobe and/or basal temporal veins. Techniques to create the dural flap without trochlear nerve injury were also explored. CONCLUSION: The technique of tentorial peeling into two distinct layers has the potential to reduce the morbidity associated with temporal lobe retraction and venous injury. Further cadaveric studies and surgical case series are needed to validate this important surgical nuance in transpetrosal approaches.

Lariboisiere Hospital pre-operative surgical checklist to improve safety during transpetrosal approaches.

BACKGROUND: Transpetrosal approaches are technically complex and require a complete understanding of surgical and radiological anatomy. A careful evaluation of pre-operative magnetic resonance imaging and computed tomography scan is mandatory, because anatomical or pathological variations are common and may increase the risk of complications related with the approach. METHODS: Pre-operative characteristics of venous and petrous bone anatomy were analysed and correlated with intraoperative findings, using injected magnetic resonance imaging and thin-slices computed tomography scan. These data regularly checked before each transpetrosal approach were progressively included in the presented checklist. RESULTS: Transpetrosal approaches have been used in 101 patients. Items included in the checklist were petrous bone pneumatization, angle between petrous apex and clivus, dehiscence of petrous carotid artery, dehiscence of geniculate ganglion, distance between superior semicircular canal and middle fossa floor, distance between cochlea and middle fossa floor, sigmoid sinus dominance, transverse sigmoid sinus junction depth to the outer cortical bone, jugular bulb height (high or low), location of the vein of Labbé, characteristics of superior petrosal vein complex. CONCLUSION: The presented checklist provides a systematic scheme of consultation of characteristic of venous and petrous bone anatomy for transpetrosal approaches. In our experience, the use of this checklist reduces the risk of complications related with approach, by minimizing the neglect of crucial information.

The mini-combined transpetrosal approach: an anatomical study and comparison with the combined transpetrosal approach.

BACKGROUND: The combined transpetrosal approach (CTPA) is a versatile technique suitable for challenging skull base pathologies. Despite the advantages provided by a wide surgical exposure, the soft tissue trauma, complex and time-consuming bony work, and cosmetic issues make it far from patient expectations. In this study, the authors describe a less invasive modification of the CTPA, the mini-combined transpetrosal approach (mini-CTPA), and perform a quantitative comparison between these two approaches. METHODS: Five human specimens were used for this study. CTPA was performed on one side and mini-CTPA on the opposite side. The surgical freedom, petroclival and brainstem area of exposure, and maneuverability for 6 anatomical targets, provided by the CTPA and mini-CTPA, were calculated and statistically compared. The bony volumes corresponding to each anterior petrosectomy were also measured and compared. Three clinical cases with an operative video are also reported to illustrate the effectiveness of the approach. RESULTS: The question-mark skin incision done along the muscle attachments permits an optimal cosmetic result. Even though the limited incision, the smaller craniotomy, and the less extensive bone drilling of mini-CTPA provide a smaller area of surgical freedom, the areas of exposure of petroclival region and brainstem were not statistically different between the two approaches. The antero-posterior maneuverability for the oculomotor foramen (OF), Meckel's cave (MC) and the REZ of trigeminal nerve, and the supero-inferior maneuverability for OF, MC, Dorello's canal, and REZ of CN VII are significantly reduced by the smaller opening. The bony volume of anterior petrosectomy resulted similar among the approaches. CONCLUSIONS: The mini-CTPA is an interesting alternative to the CTPA, providing comparable surgical exposure both for petroclival region and for brainstem. Although the lesser soft tissue dissection and bony opening decrease the surgical maneuverability, the mini-CTPA may reduce surgical time, potential approach-related morbidities, and improve cosmetic and functional outcomes for the patients.

A new simple and free tubular device for microscopic transcortical approach to deep-seated lesions: technical note and case example.

BACKGROUND: Surgery for deep-seated brain tumors remains challenging. Transcortical approaches often require brain retraction to ensure an adequate surgical corridor, thus possibly leading to brain damage. Various techniques have been developed to minimize brain retraction such as self-retaining retractors, endoscopic approaches, or tubular retractor systems. Even if they evenly distribute the mechanical pressure over the parenchyma, rigid retractors can also cause some degree of brain damage and have significant disadvantages. We propose here a soft cottonoid retractor for microscopic resection of deep-seated and ventricular lesions. METHODS: Through a small corticectomy, a channel route with a blunt cannula is developed until the lesion is reached. Then, a "balloon-like system" made with a surgical glove is progressively inflated, dilatating the surgical corridor. A mini-tubular device, handmade by suturing a surgical cottonoid, is positioned into the corridor, unfolded, and sutured to the edge of the dura, to prevent it from being progressively expelled from the working channel. This allows a good visualization of the lesion and surrounding structures under the microscope. RESULTS: Advantages of this technique are the softness of the tube walls, the absence of rigid arm to hold the tube, and the possibility for the tube to follow the movements of the instruments and to modify its orientation according to the working area. CONCLUSION: This simple and inexpensive tubular working channel for microscopic transcortical approach is a valuable alternative technique to traditional self-retaining retractor and rigid tube for the microsurgical resection of deep-seated brain tumors.