Deep learning based identification of pituitary adenoma on surgical endoscopic images: a pilot study.

Accurate tumor identification during surgical excision is necessary for neurosurgeons to determine the extent of resection without damaging the surrounding tissues. No conventional technologies have achieved reliable performance for pituitary adenomas. This study proposes a deep learning approach using intraoperative endoscopic images to discriminate pituitary adenomas from non-tumorous tissue inside the sella turcica. Static images were extracted from 50 intraoperative videos of patients with pituitary adenomas. All patients underwent endoscopic transsphenoidal surgery with a 4 K ultrahigh-definition endoscope. The tumor and non-tumorous tissue within the sella turcica were delineated on static images. Using intraoperative images, we developed and validated deep learning models to identify tumorous tissue. Model performance was evaluated using a fivefold per-patient methodology. As a proof-of-concept, the model's predictions were pathologically cross-referenced with a medical professional's diagnosis using the intraoperative images of a prospectively enrolled patient. In total, 605 static images were obtained. Among the cropped 117,223 patches, 58,088 were labeled as tumors, while the remaining 59,135 were labeled as non-tumorous tissues. The evaluation of the image dataset revealed that the wide-ResNet model had the highest accuracy of 0.768, with an F1 score of 0.766. A preliminary evaluation on one patient indicated alignment between the ground truth set by neurosurgeons, the model's predictions, and histopathological findings. Our deep learning algorithm has a positive tumor discrimination performance in intraoperative 4-K endoscopic images in patients with pituitary adenomas.

Development of machine learning models for predicting unfavorable functional outcomes from preoperative data in patients with chronic subdural hematomas.

Chronic subdural hematoma (CSDH) often causes neurological deterioration and is treated with hematoma evacuation. This study aimed to assess the feasibility of various machine learning models to preoperatively predict the functional outcome of patients with CSDH. Data were retrospectively collected from patients who underwent CSDH surgery at two institutions: one for internal validation and the other for external validation. The poor functional outcome was defined as a modified Rankin scale score of 3-6 upon hospital discharge. The unfavorable outcome was predicted using four machine learning algorithms on an internal held-out cohort (n = 188): logistic regression, support vector machine (SVM), random forest, and light gradient boosting machine. The prediction performance of these models was also validated in an external cohort (n = 99). The area under the curve of the receiver operating characteristic curve (ROC-AUC) of each machine learning-based model was found to be high in both validations (internal: 0.906-0.925, external: 0.833-0.860). In external validation, the SVM model demonstrated the highest ROC-AUC of 0.860 and accuracy of 0.919. This study revealed the potential of machine learning algorithms in predicting unfavorable outcomes at discharge among patients with CSDH undergoing burr hole surgery.

Transvenous embolization via the facial vein for intraorbital dural arteriovenous fistula: illustrative case.

BACKGROUND: Intraorbital arteriovenous fistula (IOAVF) is a rare type of intracranial fistula that presents with ocular signs similar to those of cavernous sinus dural arteriovenous fistula. The treatment of IOAVF is based on the vascular architecture of each case due to its infrequent occurrence. The authors report the case of an IOAVF that was successfully treated with embolization via the facial vein, with good outcomes. OBSERVATIONS: A 78-year-old woman presented with left eyelid swelling, pulsatile ocular protrusion, and left ocular conjunctival hyperemia. Ophthalmological evaluation revealed elevated intraocular pressure; time-of-flight magnetic resonance angiography revealed a dilated left superior ophthalmic vein. Digital subtraction angiography showed an arteriovenous shunt in the left superior orbital fissure, which was treated using transvenous coil embolization. The patient experienced immediate improvement in left ocular protrusion and conjunctival hyperemia. Ophthalmological evaluation 1 month after treatment showed normal intraocular pressure in the left eye. No neurological symptoms were observed, and there was no recurrence of the arteriovenous shunt 3 months postoperatively. LESSONS: The authors report a rare case of IOAVF treated with embolization via the facial vein with a good outcome. A thorough understanding of the vascular architecture using three-dimensional images is useful for determining endovascular access and procedures.

The importance of preserving the superior hypophyseal artery infundibular branch in craniopharyngioma surgery.

PURPOSE: Postoperative pituitary dysfunction, a critical problem in the treatment of craniopharyngiomas, can occur even when the pituitary stalk is preserved. We hypothesized that compromise of the primary superior hypophyseal artery (pSHA) might be related to this occurrence. METHODS: We performed a retrospective review of 131 patients with craniopharyngioma who underwent surgery from April 2009 to September 2021. The inclusion criteria were initial surgery, endoscopic transsphenoidal surgery, preoperative normal pituitary function or pituitary dysfunction in one axis, and morphological preservation of the pituitary stalk. The branches of the pSHA consist mainly of the chiasmatic branches (Cb), infundibular branches (Ib), and descending branches (Db). We analyzed the association between postoperative pituitary function and preservation of these branches. RESULTS: Twenty patients met the criteria. Preoperative anterior pituitary function was normal in 18 patients, and there was isolated growth hormone deficiency in two patients. No patient had preoperative diabetes insipidus (DI). Anterior pituitary function was unchanged postoperatively in eight patients. Of these eight patients, bilateral preservation of pSHA Ib was confirmed in seven patients. Bilateral preservation of pSHA Ib was the only factor associated with preserved anterior pituitary function (p < 0.01). Fifteen patients were free of permanent DI, and the preservation of any given pSHA branch produced no significant difference in the postoperative occurrence of permanent DI. CONCLUSIONS: Our study shows that bilateral preservation of pSHA Ib provides favorable postoperative anterior pituitary function in craniopharyngioma surgery; however, such preservation may have little effect on the postoperative occurrence of DI.

Chordoma of the Clivus with Metastasis to Femur.

Chordomas are aggressive and invasive tumors that are notoriously famous for their recurrence and metastasis. They present with diverse manifestations, usually with lower cranial nerve involvement. Here, we present the first reported case of chondroid chordoma with femur metastasis. A 71-year-old lady presented to us with a headache and diplopia. MRI of the brain revealed an enhanced broad and destructive mass in the infrasellar region with complete destruction of the clivus, right cavernous sinus. She underwent multiple surgeries along with gamma knife and proton therapy. The patient later presented with a trochanteric fracture and needed a hip replacement. Biopsy curettage of the femur lesion revealed a chondroid chordoma of the femur. The patient died later of a chest infection. Multimodality treatment is required in chordoma management, including surgery, gamma knife, and proton therapy. A firm discerning eye is required in the elderly toward metastatic spread to the femur in cases presenting with fractures of long bones.

Combined Exoscopic and Endoscopic Two-Step Keyhole Approach for Intracranial Meningiomas.

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.

Combined Transcranial-endonasal Reconstructive Surgery for Cerebrospinal Fluid Leakage Resulting from Traumatic Anterior Skull Base Fractures Involving the Parasellar Region.

Extensive traumatic anterior skull base fractures from the frontal sinus to the parasellar region are frequently accompanied by multiple dural defects that cause persistent cerebrospinal fluid (CSF) leakage. Conventional transcranial reconstruction using a frontal periosteal flap is frequently insufficient, and parasellar dural defects are often deep, complex, and difficult to identify. In this report, we describe a combined transcranial-endonasal reconstructive technique and report our experience. Simultaneous combined transcranial and endoscopic surgery was performed in three patients with CSF leakage resulting from traumatic anterior skull base fractures. Dural defects were thoroughly identified from the transcranial and endonasal surgical fields, and covered using a multilayer sealing technique. The anterior regions of the anterior skull base were reconstructed using a free fascial flap and frontal periosteal flap; posterior and parasellar regions were reconstructed using a fat graft, vascularized nasoseptal flap, and endonasal balloon. Suturing the transcranial grafts to the parasellar dura mater was performed collaboratively by the transcranial and endonasal surgeons. In our cases, complete cessation of CSF leakage was achieved without perioperative lumbar drainage in all patients. Mean time to postoperative ambulation was 7 days (range, 3-11). No surgical complications occurred. Simultaneous transcranial and endonasal procedures were helpful to detect all sites of CSF leakage and secure reconstructive grafts. The combined transcranial and endonasal reconstructive technique achieved secure skull base reconstruction without recurrence of CSF leakage, and allowed early postoperative ambulation. This technique can be a reliable surgical option to repair CSF leakage resulting from extensive anterior skull base fractures.

A Practice Survey to Compare and Identify the Usefulness of Neuroendoscope and Exoscope in the Current Neurosurgery Practice.

BACKGROUND: The present era is of new tools and technique. Handling of new challenges require, better understanding of microscopic anatomy, which requires better magnification and light. Microscope has played significant role in this, use of endoscope and introduction of exoscope have given new dimensions to this field. AIM: This study aims to compare and see the advantages, disadvantages of endoscope with exoscope, will analyze the difference in terms of ergonomics, learning curve, opportunities for training, operating time, magnification, and image quality. MATERIALS AND METHODS: This study was conducted in the Department of Neurosurgery, Bantane Hospital Fujita Health University, Japan. Apart from comparing the specifications of available systems, we conducted a worldwide survey of the two systems through sending questionnaire through mail collected responses and analyzed them. RESULTS: Learning curve, magnification, image quality, and ergonomics favors exoscope but depth perception and maneuverability, hand eye coordination, tactile sensation, and usage of different angulation tubes favored endoscope to be superior to exoscope. CONCLUSION: There is more scope for modifications and research in both the instruments. These instruments are not replacement of either and should be used according to their indications.

Non-brain-exposure Exoscopic and Endoscopic Volume Reduction Surgery for Benign Meningioma En Plaque in an Elderly Patient: A Case Report.

Meningioma en plaque (MEP) often needs invasive surgery to resect totally because of its widespread proliferation along the dura mater. We report a minimally invasive surgical technique for non-brain-exposure exoscopic and endoscopic volume reduction in an elderly patient with MEP. An 83-year-old woman presented with gait disturbance and cognitive dysfunction that had progressed over 6 months. Magnetic resonance imaging (MRI) revealed a large MEP on the right frontal lobe with peritumoral edema. On confirming the benign nature of the tumor (WHO grade 1) by biopsy, the main feeders and tumor were transarterially embolized. Volume reduction surgery was performed under the assistance of an exoscope and an endoscope while being careful not to expose and damage the cortex. Her symptoms completely resolved postoperatively. This surgical technique without exposing the brain may be a treatment choice for elderly patients with benign symptomatic convexity MEP.

Endoscopic Microvascular Decompression for Hemifacial Spasm.

INTRODUCTION AND OBJECTIVE: Hemifacial spasm (HFS) is a condition, characterized by painless, involuntary unilateral tonic or clonic contractions of the facial muscles innervated by the ipsilateral facial nerve. HFS starts with contractions in the orbicularis oculi muscle with subsequent eyelid closure and/or eyebrow elevation, but may spread to involve muscles of the frontalis, platysma, and orbicularis oris muscles. Microvascular decompression (MVD) is reliable and accepted surgical treatment for HFS. MVD is the standard surgical technique now for HFS treatment with long-term success rates. MATERIALS AND METHODS: We performed fully endoscopic MVD technique for 1 patient with HFS (a 83-year-old female) at our institution. HFS was diagnosed based on the clinical history and presentation, a neurologic examination, and additional imaging findings. Respectively, the durations of HFS were 3 years, respectively. The patient had been previously treated with repeated botulinum toxin injections. Preoperative evaluation was done with magnetic resonance imaging; three-dimensional computed tomography fusion images examinations had identified the anterior inferior cerebellar artery (AICA) as the offending vessel in this patient. RESULTS: The patient with HFS was treated by fully endoscopic MVD technique. The AICA, which had been identified as the offending vessel by preoperative magnetic resonance imaging, was successfully decompressed. No surgery-related complications occurred and had excellent outcomes with the complete resolution of HFS immediately after the operation. CONCLUSIONS: Endoscopic surgery can provide a more panoramic surgical view than conventional microscopic surgery. Fully endoscopic MVD is both safe and effective in the treatment of HFS. This method minimizes the risks of brain retraction and extensive dissection often required for microscopic exposure. Endoscopic MVD is safe and has advantage over microscope in terms of visualization of structure, identification of neurovascular conflict, but it has a learning curve and technically challenging.

Exclusive Endoscopic Occipital Transtentorial Approach for Pineal Region Tumors.

OBJECTIVE: Removal of pineal region tumors, which are deeply placed and encircled by intricate neurovascular structures, is challenging to neurosurgeons. The aim of this study was to present our experience with the exclusive endoscopic occipital transtentorial approach (EEOTA) used for removal of pineal region tumors. METHODS: A retrospective review was performed of patients who underwent surgery using the EEOTA to remove pineal region tumors from May 2016 to August 2018. The details of the EEOTA procedure were confirmed. RESULTS: Five patients underwent surgery via the EEOTA for treatment of pineal region tumors. In all cases, it was possible to perform the EEOTA less invasively through a keyhole craniotomy approximately 2.0-2.5 cm in size. The EEOTA produced an excellent view and provided natural and automatic orientation. There was essentially no blind spot in this procedure, even for the floor or ipsilateral wall of the third ventricle. Gross total resection was achieved in 4 cases. In the patient with atypical teratoid rhabdoid tumor, we abandoned gross total resection because of a hardened adhesion to the tectum and the great cerebral vein and its tributaries. Two patients presented with transient upper gaze palsy immediately after surgery but experienced complete recovery during the follow-up period. CONCLUSIONS: The EEOTA is a very promising technique for removal of pineal region tumors and has the potential for extensive and routine application for surgeons familiar with endoscopic surgery.

The Pituitary Is a Candidate Organ That Modulates Circulating Klotho Levels.

CONTEXT: The antiaging protein Klotho is shed and released into the blood stream (soluble Klotho). Growth hormone (GH) is considered an active Klotho regulator, because growth retardation is described in Klotho-deficient mice. The origin of circulating Klotho is, however, not fully understood. OBJECTIVES: Our objective was to analyze a possible role of the pituitary in regulating soluble Klotho in patients with pituitary adenomas. PATIENTS DESIGN AND SETTING: We analyzed serum levels of soluble Klotho, GH, and insulin-like growth factor 1 (IGF-1) from 21 consecutive patients in our center with pituitary tumor, 7 with GH-producing adenomas (GHomas), and 14 with non-GH-producing pituitary adenomas (non-GHomas), before and after endoscopic transsphenoidal surgery (eTSS). MAIN OUTCOME MEASURE: Soluble Klotho levels were determined by ELISA with antihuman Klotho antibodies. RESULTS: Baseline soluble Klotho levels in all patients, those with GHoma and those with non-GHoma, were 542 (median) (interquartile range: 403, 652), 1083 (425, 1213), and 525 (399, 590), respectively. A drastic reduction in Klotho levels was identified in those with GHoma, accompanied by decreases in GH and IGF-1 levels, after eTSS. Interestingly, patients with non-GHoma had significant declines in soluble Klotho without any significant changes in GH levels. Moreover, an oral glucose tolerance test revealed that soluble Klotho levels decreased, whereas a paradoxical GH peak was observed after glucose intake in a patient with GHoma. CONCLUSIONS: Our data suggest that the pituitary may be a key organ that regulates circulating Klotho concentrations, implying that the pituitary possibly controls circulating Klotho through GH-dependent and/or GH-independent mechanisms.

Quality of Life Changes Before and After Transsphenoidal Surgery for Sellar and Parasellar Lesions.

OBJECTIVE: Although reports regarding the relationship between surgical complications and quality of life (QOL) exist, a general consensus regarding this issue is lacking. The aim of this study was to evaluate QOL after endoscopic transsphenoidal approach. METHODS: We assessed patients with sellar or parasellar lesions that were removed with endoscopic transsphenoidal approach or extended endoscopic transsphenoidal approach between January 2010 and December 2016. 36-Item Short Form Health Survey and 30-Item General Health Questionnaire QOL scores were obtained preoperatively and 1 month and 6 months postoperatively. RESULTS: We analyzed 89 patients with nonfunctioning pituitary adenoma (NFPA) and 39 patients with acromegaly. Physical QOL decreased 1 month after surgery but recovered after 6 months in both groups. Mental QOL improved postoperatively compared with preoperatively. Patients with acromegaly had a worse Physical Component Summary (PCS) on 36-Item Short Form Health Survey (48.7, 28.9, and 41.0) at 6 months than patients with NFPA. The low preoperative PCS group did not improve until 6 months postoperatively. Multiple regression analysis revealed the following factors were key to postoperative QOL: age (NFPA PCS 6 months postoperatively; correlation coefficient = -0.489), preoperative Mental Component Summary (MCS) (NFPA MCS 6 months postoperatively, correlation coefficient = 0.573), body mass index (acromegaly PCS 6 months postoperatively; correlation coefficient = -0.376), preoperative PCS (acromegaly PCS 6 months postoperatively; correlation coefficient = 0.905), and preoperative MCS (acromegaly MCS 6 months postoperatively; correlation coefficient = 0.726). CONCLUSIONS: Endoscopic transsphenoidal approach can improve QOL in patients by 6 months postoperatively. In patients with acromegaly with significant QOL impairments preoperatively, surgery sometimes may be unable to normalize QOL.

Neuroendoscopic Cylinder Surgery and 5-Aminolevulinic Acid Photodynamic Diagnosis of Deep-Seated Intracranial Lesions.

BACKGROUND: Microscopic detection of intracranial brain tumors with 5-aminolevulinic acid (5-ALA) has proven extremely useful, and reports the use of 5-ALA have recently increased. However, few reports have described 5-ALA photodynamic diagnosis (PDD) using a neuroendoscope. We performed neuroendoscopic 5-ALA PDD for various brain lesions and present a procedure using only a neuroendoscope. METHODS: We describe the diagnosis of 20 intracranial brain lesion cases with a 5-ALA-guided fluorescence endoscope. A light-emitting diode that emitted either white light or 400- to 410-nm violet light was attached to a neuroendoscope. We performed cylinder surgery with a transparent sheath under observation with a rigid neuroendoscope. RESULTS: Neuroendoscopic biopsies were performed in 11 patients, and resections were performed in 9 patients. All lesions were observed with a neuroendoscope under sequential white light and violet light. We confirmed the presence of a red fluorescent lesion under violet light in 15 patients, including 4 of 5 glioblastoma cases (80%); 1 of 2 anaplastic astrocytoma cases (50%); 4 of 5 diffuse large B cell lymphoma cases (80%); 2 of 2 metastatic brain tumors; 1 of 1 case each of diffuse astrocytoma, pilocytic astrocytoma, inflammatory change, and germinoma (100%); and no cases of anaplastic ependymoma or cysticercosis. Pretargeted lesions were accurately harvested from all biopsy specimens. Gross total resection was achieved in 5 of 9 patients using a resection procedure. CONCLUSIONS: Our described method offers a promising technique for achieving precise brain tumor biopsies and safe resection.

Tumor Volume Decrease via Feeder Occlusion for Treating a Large, Firm Trigone Meningioma.

Trigone meningiomas are considered a surgical challenge, as they tend to be considerably large and hypervascularized at the time of presentation. We experienced a case of a large and very hard trigone meningioma that was effectively treated using initial microsurgical feeder occlusion followed by surgery in stages. A 19-year-old woman who presented with loss of consciousness was referred to our hospital for surgical treatment of a brain tumor. Radiological findings were compatible with a left ventricular trigone meningioma extending laterally in proximity to the Sylvian fissure. At initial surgery using the transsylvian approach, main feeders originating from the anterior and lateral posterior choroidal arteries were occluded at the inferior horn; however, only a small section of the tumor could initially be removed because of its firmness. Over time, feeder occlusion resulted in tumor necrosis and a 20% decrease in its diameter; the mass effect was alleviated within 1 year. The residual meningioma was then totally excised in staged surgical procedures after resection became more feasible owing to ischemia-induced partial softening of the tumor. When a trigone meningioma is large and very hard, initial microsurgical feeder occlusion in the inferior horn can be a safe and effective option, and can lead to necrosis, volume decrease, and partial softening of the residual tumor to allow for its staged surgical excision.

Fully endoscopic combined transsphenoidal and supraorbital keyhole approach for parasellar lesions.

OBJECTIVE Parasellar tumors that extend far laterally beyond the internal carotid artery or that are fibrous and adhere firmly to critical structures are difficult to remove totally via the endoscopic transsphenoidal approach alone. In such cases, a combined transsphenoidal-transcranial approach is effective to achieve maximal resection in a single stage. In this paper, a new minimally invasive surgical technique for complicated parasellar lesions, a fully endoscopic combined transsphenoidal-supraorbital keyhole approach, is presented. METHODS A retrospective review of patients who had been treated via a fully endoscopic combined transsphenoidal-supraorbital keyhole approach for complicated parasellar lesions was performed. The data for resection rate, perioperative mortality and morbidity, and postoperative outcomes were analyzed. RESULTS A total of 12 fully endoscopic combined transsphenoidal-supraorbital keyhole approaches were performed from March 2013 to February 2016; 10 were for pituitary adenomas and 2 were for craniopharyngiomas. Gross-total resection or near-total resection was achieved in 7 of 12 cases. Among the 11 patients who had presented with preoperative visual disturbances, 7 had visual improvement. However, 1 patient showed deterioration in visual function. No patient experienced postoperative hemorrhage, needed additional surgical treatment, or had postoperative CSF leakage. CONCLUSIONS In the combined transsphenoidal and transcranial approach, safe and effective cooperative manipulation with 2 surgical corridors can be performed for complicated parasellar lesions. The goal of this procedure is not to achieve gross-total resection, but to achieve safe resection. Moreover, this new surgical approach offers neurosurgeons a simpler operative field with less invasiveness than the conventional microscopic combined approach. The fully endoscopic combined endonasal-supraorbital keyhole approach is an efficacious procedure for complicated parasellar lesions with acceptable results.

Development of Pyriform Sinus Suctioning Programs for Aspiration Pneumonia Prevention During the Acute Stroke.

Aspiration due to dysphagia is a factor associated with pneumonia during acute stroke. In such cases, it is likely that secretions in the pyriform sinuses enter the laryngeal inlet. The present study was based on the idea that it is possible to reduce aspiration pneumonia by periodically suctioning and removing such secretions (pyriform sinus suctioning), a study was conducted in a single facility. The incidence of pneumonia as a dependent variable was compared between before (control) and after (intervention group) intervention with pyriform sinus suctioning as an independent variable. With a view of unifying the quality and frequency of intervention, two programs to: initially confirm the safety of such suctioning; subsequently enhance/evaluate knowledge and skills related to the procedure (educational); and specify conditions for the implementation and criteria for determining its appropriateness (practical), were developed. The study involved 33 (mean age: 74.6 ± 12.4) and 30 (80.0 ± 8.8) control and intervention group members, respectively, 25 (83.3%) of the latter were treated with pyriform sinus suctioning for 5 days after a stroke. Pneumonia developed in 7 (21.2%) and 2 (6.7%) of the former and latter, respectively. As individuals with a Japan Coma Scale (JCS) score of III or a midline shift on head CT tend to develop pharyngeal dysphagia, the patients were also divided into 2 groups to compare the incidence of pneumonia based on the risk level: low: Japan Coma Scale scores of I-II without a midline shift on head CT; and high: scores of II-III with it. In the latter, the incidence after intervention was markedly lower (p = 0.06, φ = 0.326), while the former did not show changes (p = 0.574, φ = 0.066), supporting the effectiveness of pyriform sinus suctioning to prevent aspiration pneumonia among patients with a low risk level.

The Multiscope Technique for Microvascular Decompression.

BACKGROUND: Endoscopic surgery has rapidly become widespread in neurosurgery in recent years. Endoscopy can offer close and panoramic surgical views with fine illumination, even in the deep intracranial area. However, it also has the following serious drawback: an intracranial blind area between the field lens of the endoscope and the site of the dural opening. This blind area cannot be viewed on the endoscopic monitor, and several surgical complications, including accidental intracranial neurovascular structural injury, can occur in this area. In this article, we report a new multiscope surgical technique that can compensate for this serious disadvantage of endoscopic surgery. METHODS: In the multiscope technique, endoscopic and exoscopic systems are used simultaneously with 2 monitors. Microvascular decompression (MVD) is performed fully endoscopically using an exoscope that compensates for the intracranial blind area of the endoscopic view. Two high-definition monitors for the endoscope and exoscope are placed side-by-side in front of the primary surgeon. RESULTS: Two patients with hemifacial spasm were treated by endoscopic MVD with the multiscope technique. In these procedures, fine surgical views were obtained by both the endoscope and exoscope. Two monitors were placed side-by-side in front of the surgeon; as a result, the physician could easily view them simultaneously during the operation. No surgery-related complications occurred. CONCLUSIONS: The multiscope technique can facilitate the performance of safer neuroendoscopic surgery than conventional endoscopic surgery. This technique can also be adopted in other skull base surgeries, in which the importance of endoscopy is growing.

Endoscopic approach via the interhemispheric fissure: the role of an endoscope in a surgical case of multiple falcine lesions.

BACKGROUND: For treating a patient with multiple falcine and parasagittal lesions, we believe that it is beneficial to resect the maximum possible number of lesions during one operation, even if some lesions are asymptomatic. This practice can potentially reduce the total number of operations during a patient's lifetime. METHODS: We provide an introduction of a concurrent endoscopic approach via the interhemispheric fissure. CONCLUSIONS: Applying this endoscopic approach concurrently with conventional microscopic surgery can enable the safe resection of as many lesions as possible during one operation.