OBJECTIVE: Resections of symptomatic Rathke\'s cleft cysts (RCCs) are mainly performed via an endonasal transsphenoidal approach. However, there is a lack of equivalent data in current literature concerning transcranial keyhole approach in the treatment of RCCs. In order to find general recommendations for the surgical treatment of RCCs also with regard to recurrence, the object of this study is the analysis and comparison of both techniques.
METHODS: Twenty-nine patients having been surgically treated between January 2004 and August 2019 were retrospectively analysed. The transsphenoidal approach was chosen in 16 cases and the transcranial keyhole approach in 13 cases. Both surgical techniques were analyzed and compared concerning preoperative symptoms and cyst characteristics, complications, surgical radicality, endocrinological and ophthalmological outcome and recurrences in patients´ follow up.
RESULTS: The postoperative outcome of both techniques was identic and showed highly satisfying success rates with 92% for neurological deficits, 82% for endocrinological dysfunctions and 86% for visual deficits. In contrast, momentous postoperative complications were significantly more likely after transsphenoidal operations. After a mean follow-up time of 5.7 years, the recurrence rates of both cohorts were the same with 0% each.
CONCLUSIONS: Regarding its equal outcome with its lower complication rate, the authors suggest using the supraorbital keyhole approach for RCCs whose anatomical configuration allow both techniques. Yet, the decision should always consider the surgeon\'s personal experience and other individual patient characteristics. Further studies with higher numbers of cases and longer follow-up periods are necessary to analyse the effect of the selected approach on recurrence.

UNASSIGNED: The increasing prevalence of unruptured intracranial aneurysms, detected through advanced brain imaging, necessitates a cautious approach to surgical intervention, with a focus on minimizing associated risks. This retrospective study explores the safety and better aesthetic outcomes of a Virtual Reality (VR) guided Focused Sylvian Approach (FSA) in comparison to the standard Pterional Surgical Approach (SPA) for the clipping of unruptured small-medium-size (<10 mm) Middle Cerebral Artery (MCA) aneurysms.
UNASSIGNED: 23 patients with 23 unruptured MCA aneurysms underwent the VR-guided FSA from June 2020 to September 2023, while 22 patients with 23 unruptured MCA aneurysms who underwent SPA were retrospectively recruited from the medical records database from January 2017 to May 2020. The comparative analysis involved surgical duration, postoperative complications, hospital stay, and a three-month follow-up patient\'s sequela survey.
UNASSIGNED: All aneurysms were effectively treated. The FSA procedure demonstrated a shorter surgical duration compared to the SPA group (164 ± 48 min vs. 196 ± 133 min, P = 0.2974). Despite a slightly higher median age in the FSA group (59 vs. 56 years), the median hospital stay was shorter in the FSA group (6 days) compared to the SPA group (7 days). The SPA group exhibited a higher incidence of complications (17/23) including cephalalgia, scar irritation, scar numbness, and temporal muscle dysfunction, compared to the FSA group (1/23), with a statistical significance of P < 0.05. Although FSA cannot demonstrate significant surgical efficiency in surgical duration and hospitalization, its superior aesthetics and preservation of temporalis muscle function compared to the SPA group.
UNASSIGNED: The VR-guided FSA offers improved aesthetics and preservation of muscle function compared to the SPA. Our retrospective study underscores the potential benefits of VR-guided, personalized, focused Sylvian approaches for managing unruptured small-medium-size MCA aneurysms.

OBJECTIVE: By maximizing the advantages of exoscopy, we developed a keyhole approach for intracranial hematoma removal. Herein, we validated the utility of this procedure, and compared it with conventional microscopic hematoma removal and endoscopic hematoma removal in our institution.
METHODS: We included 12 consecutive patients who underwent this procedure from June 2022 to March 2024. A 4-cm-long skin incision was made, and a keyhole craniotomy (diameter, 2.5 cm) was performed. An assistant manipulated a spatula, and an operator performed hematoma removal and hemostasis using typical microsurgical techniques under an exoscope. The dura mater was reconstructed without sutures using collagen matrix and fibrin glue. The outcomes of this series were compared with those of 12 consecutive endoscopic hematoma removals and 19 consecutive conventional microscopic hematoma removals from October 2018 to March 2024.
RESULTS: The mean age was 72±10 years, and 7 (58%) patients were men. Hematoma location was the putamen in 5 patients and subcortical in 7 patients. The mean operative time was 122±34 min, the mean hematoma removal rate was 95%±8%, and the mortality rate was 0%. Although the preoperative hematoma volume was similar between the 3 groups, the operative time and total time in the operating room was significantly shorter in the exoscope group than in the microscope group (P<0.0001).
CONCLUSIONS: This procedure may be simpler and faster than conventional microscopic hematoma removal, and comparable to endoscopic hematoma removal.

Objective  The study aimed to provide neuroanatomical justification of the extradural resection of the anterior clinoid process (ACP). Material and Method  Using a cross-sectional study design, 47 cranial computed tomography (CT) scans were examined. There were 31 (65.96%) females aged 28 to 79 years. The measured dimensions were ACP length and width, and optic strut (OS) width. Index (i acp ) was measured as the ratio of ACP width to ACP length. The ACP volume and working operating field (WOF) volume were measured using Syngo.via Siemens program. The percentage expansion of WOF after removal of the ACP was estimated on 5 fixed human cadaver heads with the exoscope VITOM 3D. The possibilities of the combined approach were demonstrated in a clinical case. Results  The mean ACP lengths were 11.31 ± 2.76 and 11.54 ± 2.86 mm, on the right and left, respectively. The mean ACP widths were 7.70 ± 1.66 and 7.64 ± 1.67 mm, on the right and left, respectively. Average i acp was 0.67 (minimum 0.45; maximum 0.90). The width of the OS varied in the range from 1.37 to 4.75 mm. The average volume of right ACP was 0.71 ± 0.16 cm 3 , right WOF was 3.26 ± 0.74 cm 3 , left ACP was 0.71 ± 0.15 cm 3 , left and WOF was 3.20 ± 0.76 cm 3 . Removal of the right ACP expanded the right WOF by 22.21 ± 3.88%, and left ACP by 22.78 ± 5.50%. There was an approximately 25% increase in the WOF from the cadaveric dissections. Taking into account the variability of the ACP and OS, we proposed our own surgical classification of complicated (i acp ≥ 0.67; medium OS 2.5 mm ≤ 4.0 mm; wide OS ≥ 4.0 mm; ACP with pneumatization) and uncomplicated ACP (i acp 0.45 ≤ 0.67 mm; i acp ≤ 0.45; narrow OS ≤ 2.5 mm; ACP without pneumatization). Using this classification, we developed an algorithm for ACP dissection and removal. This was piloted in a clinical case of microsurgical clipping of a left internal carotid artery-posterior communicating artery aneurysm via the left minipterional approach. Conclusion  Extradural removal of ACP expands the WOF by approximately 25%, it helps neurosurgeons to improve proximal vascular control and avoid complications, and expands the range of indications for neurosurgical interventions in the skull base area.

Skull base chondrosarcoma is rare, arising from the clivus or petroclival junction, and usually presents as ocular motility disorders. Endonasal transsphenoidal surgery may be performed in some cases of midline clivus chondrosarcoma. Chondrosarcoma is located within the cavernous sinus and presents a softer/gelatinous mass and can be removed with suctions and curettage. We have been using a simple intradural keyhole transcavernous approach, avoiding a complex extradural transcavernous dissection.
The intracavernous chondrosarcoma was removed via a 5 mm keyhole opening over the Parkinson\'s triangle using a standard frontotemporal intradural approach.
Minimally invasive keyhole surgical resection can be performed to eradicate skull base chondrosarcomas, avoiding complex extradural cranial base approaches.

Paraclinoid aneurysms represent a challenge for neurosurgeons due to the anatomical complexity of this region. Then, innovative techniques such as the extradural sphenoid ridge approach are suitable for a safe microsurgical clipping.
A description of the surgical technique was made by the senior author, a vascular neurosurgeon experienced with the use of this approach in the management of paraclinoid aneurysms exemplified through a clinical case.
Microsurgical clipping through an extradural sphenoid ridge keyhole approach for small and midsize paraclinoid aneurysms is an excellent treatment modality with good clinical and surgical results.

The retrosigmoid craniotomy is a versatile surgical approach to the cerebellopontine angle though cerebrospinal fluid leak remains a concern, with a reported prevalence of 0-22 %. A host of closure materials and strategies have been proposed to achieve a watertight dural closure to varying degrees of success. We review our series of keyhole retrosigmoid craniotomies and describe our simple, standardized method of closure without watertight dural closure.
A retrospective review of all retrosigmoid craniotomies performed by the senior author was completed. Closure was achieved by placing an oversized piece of gelatin in the subdural space. The dura is grossly approximated. An oversized sheet of collagen matrix is placed as an overlay followed by gelatin sponge in the craniectomy defect held in place with titanium mesh. The superficial layers are approximated. The skin is closed with a running sub-cuticular suture followed by skin glue. Patient demographics, cerebrospinal fluid leak risk factors, and surgical outcomes were determined.
A total of 114 patients were included. There was one case (0.9 %) of CSF leak, which resolved with placement of a lumbar drain for 5 days. The patient had one defined risk factor (morbid obesity, BMI 41.0 kg/m2).
Obtaining a watertight dural layer closure has been the generally accepted strategy in preventing CSF leaks in a traditional retrosigmoid approach. In keyhole retrosigmoid approaches it may not be necessary by utilizing a simple gelfoam bolstered collagen matrix onlay technique potentially improving outcome measures including operative time.

Surgical resection of infiltrating glial neoplasms has proven to improve quality of life and confer a significant survival benefit. As accumulating evidence cements the role of surgery in grade 4 gliomas, there is a general trend to transition away from traditional large craniotomies to smaller \'keyhole\' approaches, which aim to reduce the trauma and complication profiles associated with large exposures. A keyhole approach uses a small craniotomy positioned perfectly to reach at least all the target structures that a conventional approach would reach. We present a case series of operated butterfly gliomas grade 4 patients through keyhole approaches. All three operated patients have better survival than the literature biopsy groups. The resection of butterfly gliomas should be considered in selected cases. For some patients, it is feasible with the technology used nowadays, with improved quality of life and better survival prognosis.

The advantages of neuroendoscopic surgery are the wide viewing angle and the freedom of an axis of view with minimal surgical trauma. With the advent of the exoscope, which has similar advantages to endoscopy, such as a small body and ergonomically superior heads-up surgery, it has become possible to add a field of view that is similar to that of microsurgery to endoscopic surgery. By taking advantage of the features of these scopes, we report the usefulness of the minimally invasive combined exoscopic and endoscopic two-step keyhole approach (EEKA) for various types of meningiomas. We reviewed data from 34 consecutive cases of EEKA for various types of intracranial meningiomas compared with that of conventional microsurgery. All of the tumors were resected as planned without severe complications. Significantly better outcome data were obtained in terms of the blood loss and the surgical time in the EEKA group, in addition to the craniotomy size. The well-illuminated fine vision in the deep corners by the endoscope enabled radical resection of the tumors with minimum burden on the patients. This technique has the potential for minimally invasive surgery in intracranial meningioma patients, including the older population.

BACKGROUND: While keyhole neurosurgery is increasingly utilized in the operating room, there are few reports regarding the use of keyhole techniques to resect giant intracranial tumors. The feasibility and technique of that were discussed in this paper.
METHODS: We retrospectively reviewed 95 consecutive patients who were admitted to our service between February 2012 and September 2017 with a maximum intracranial tumor diameter >5 cm. Keyhole approaches were used to resect these tumors in each case, including supraorbital, subtemporal, suboccipital, retromastoid, frontal, temporal, occipital, parietal, pterional, a combined temporo-parietal keyhole approach, and an approach via the longitudinal fissure.
RESULTS: We achieved gross total resection in 68/95 cases (71.6%) and subtotal resection in 27/95 cases (28.4%). No surgical death or severe disabilities such as coma and limb dyskinesia occurred following surgery. At the time of discharge, 8 patients had complications related to impaired cranial nerve function. In addition, 2 patients developed hydrocephalus requiring ventriculo-peritoneal shunt placement, and 4 patients developed a postoperative CSF leak requiring surgical intervention.
CONCLUSIONS: With meticulous design and reasonable selection, resection of giant intracranial tumors utilizing minimally invasive keyhole approaches can be done safely with satisfactory surgical outcomes.