Endoscopic Evacuation of Putaminal Hemorrhage Using the Trans-Middle Temporal Gyrus Approach: Technical Notes and Case Presentations

BACKGROUND

 The development of minimally invasive endoscopic neurosurgery has enabled widespread application of endoscopic surgery via the ipsilateral transfrontal approach for putaminal hematoma evacuation. However, this approach is unsuitable for putaminal hematomas that extend into the temporal lobe. We adopted the endoscopic trans-middle temporal gyrus approach, instead of the conventional surgical approach, for the management of these complicated cases and determined its safety and feasibility.

METHODS

 Twenty patients with putaminal hemorrhage underwent surgical treatment at the Shinshu University Hospital between January 2016 and May 2021. Of these, two patients with left putaminal hemorrhage that extended into the temporal lobe underwent surgical treatment using the endoscopic trans-middle temporal gyrus approach. The procedure entailed the use of a thinner transparent sheath to reduce the technique's invasiveness, a navigation system to determine the location of the middle temporal gyrus and the sheath's trajectory, and an endoscope with a 4K camera for higher image quality and utility. The sylvian fissure was compressed superiorly using our novel "port retraction technique" (i.e., by tilting the transparent sheath superiorly) to avoid damage to the middle cerebral artery and Wernicke's area.

RESULTS

 The endoscopic trans-middle temporal gyrus approach allowed sufficient hematoma evacuation and hemostasis under endoscopic observation without any surgical complexities or complications. The postoperative course was uneventful in both patients.

CONCLUSION

 The endoscopic trans-middle temporal gyrus approach for putaminal hematoma evacuation helps avoid damage to normal brain tissue, which could result from the wide range of motion of the conventional technique, particularly when the hemorrhage extends to the temporal lobe.

A new very-small-bore Simmons guiding sheath for transradial neurointervention: Technical note and initial experience

Transradial access during neurointerventions has increased in popularity because of reduced complications and patient preference. Nevertheless, transradial cannulation into the left common carotid artery can be difficult technically because of the lack of catheter support in the aortic arch. Furthermore, the use of large sheaths can increase the risk of complications at the access site. Here, we developed a new very-small-bore transradial system using a 3F Simmons guiding sheath, to increase the procedural success rate and minimize access-site complications. This system can represent a valuable treatment option for neurointerventions and has the potential to expand the indications for transradial access.

Anodal Electrical Taste Stimulation to the Chin Enhances the Salt Taste Perception in Subarachnoid Hemorrhage Patients

Aneurysmal subarachnoid hemorrhage (SAH) is a critical condition associated with high mortality rates. Hypertension is a significant risk factor for SAH development and recurrence following coil embolization for a ruptured aneurysm. While reduction of salt consumption is crucial for managing hypertension, it often compromises food taste. Anodal electrical taste stimulation (ETS) has been proposed to enhance taste perception without altering salt content. We present the case of a 69-year-old female SAH patient with a ruptured aneurysm at the anterior communicating artery who underwent coil embolization and in whom we tested ETS's efficacy in enhancing the salt taste perception on day 42 after the procedure. ETS effectively enhanced the salt taste perception threshold and perceived concentration; the threshold for salt taste without electrical stimulation was 0.8% of salt-impregnated filter paper, whereas that with electrical stimulation was 0.6%. The perception of salt taste was enhanced: 0.8% and 1.0% of filter papers were perceived as 0.6% and 0.8% without electrical stimulation and 1.0% and 1.2% with electrical stimulation, respectively. This is the first report describing the salt perception-enhancing effect of ETS in an actual patient. Further studies involving actual patients are required to determine how ETS affects habitual salt intake and blood pressure trends.

Proposed imaging assessment score for aneurysmal subarachnoid hemorrhage correlated with prognosis: Shinshu Aneurysmal subarachnoid hemorrhage score

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) imaging has been shown to correlate with prognosis. However, no numerical index of bleeding severity has been established. This study aimed to propose a new simple scoring system for computed tomography imaging of aSAH and to confirm its effectiveness in retrospective and prospective studies.

METHODS

We devised an image evaluation system as an objective index. This system was established by scoring six items, with a maximum total of 19 points. Using this score, named the Shinshu Aneurysmal Subarachnoid Hemorrhage Score (S-score), we performed a retrospective study of 210 patients with aSAH at a single institution to confirm its efficacy. Age and World Federation of Neurosurgical Societies grades were adopted as other verification items, and the modified Rankin Scale was used for prognostic evaluation. A multicenter prospective study was then conducted to examine the function of the score by examining 214 patients with aSAH.

RESULTS

In the retrospective study, the threshold of the S-score between good and poor prognoses was 9/19 points. The area under the curve by receiver operating characteristic analysis of the S-score was 0.819, suggesting efficacy, with an odds ratio (OR) of 1.291 (1.077-1.547). In the prospective study, the judgment capability of the S-score was evaluated with a sensitivity of 0.674, specificity of 0.881, positive predictive value of 0.789, negative predictive value of 0.804, false-positive ratio of 0.119, false-negative ratio of 0.325, positive likelihood ratio of 6.072, and negative likelihood ratio of 1.369. S-score showed a significant difference in prognosis. The OR was 1.183 (1.009-1.388).

CONCLUSIONS

The scoring system could contribute to patient prognosis assessment. S-score and its prognostic formulas may serve as an objective source of information in the development of clinical medicine.

[Impact of migraine on family members: an investigation by Impact of Migraine on Partners and Adolescent Children (IMPAC)]

Using the Japanese version of the Impact of Migraine on Partners and Adolescent Children (IMPAC) and Family Question prepared based on IMPAC, we investigated the impact of migraine on family members from the perspectives of both patients and their family members. Our results showed that migraine had an impact on the family members living with the patients in Japan as well, and the perception of migraine differed partially between patients and their family members. We also found that the Japanese version of the IMPAC showed a correlation with existing instruments to evaluate impact of migraine, indicating its validity. The application of this study's findings in clinical practice could help alleviate the disease burden of migraine on patients and their family members.

Endoscopic endonasal transsphenoidal surgery in acromegaly with conchal sphenoid sinus

BACKGROUND

A conchal non-pneumatized sphenoid sinus tends to be considered as unfavorable for transsphenoidal surgery because of procedural difficulties. Especially in acromegalic patients, the proportion of the conchal type of sphenoid sinus is potentially high compared with that of other patients who have a pituitary tumor. This report investigates the characteristics and surgery of the conchal type of sphenoid sinus in acromegaly along with the internal bone properties.

CLINICAL PRESENTATION

A 70-year-old man with acromegaly underwent endoscopic endonasal transsphenoidal surgery. Intraoperatively, the anterior wall of the non-pneumatized sphenoid was cortical, however, the cancellous bone was very soft, included fatty tissue, and was easily removed by suction. The sellar lesion could be reached without any problems, and finally, total tumor resection was achieved.

CONCLUSION

Based on this surgical case, the conchal sphenoid sinus of acromegaly is not always homogeneous solid bone but may contain soft fatty tissue. Therefore, although the sphenoidal characteristics may have an impact on the surgical procedures, precise assessment pre- and intraoperatively can make transsphenoidal surgery with conchal sphenoid sinus feasible.

Intraspinal canal platform system for coil embolization of anterior spinal artery aneurysm associated with spinal cord arteriovenous malformation: a case report and literature review

BACKGROUND

The prognosis for spinal artery aneurysms associated with spinal cord arteriovenous malformations (AVMs) is poor because of the high rupture rate of aneurysms. However, endovascular treatment remains technically difficult because the catheter system must be constructed via the small-caliber anterior spinal artery (ASA) or posterior spinal artery (PSA), which feeds functionally eloquent spinal cord. A 2.6F Carnelian HF-S microcatheter (Tokai Medical Products, Aichi, Japan) has been specifically designed to assist a 1.6F Carnelian MARVEL S microcatheter (Tokai Medical Products) as a small-profile 'platform catheter' close to the target lesion. Here we present a prenidal ASA aneurysm treated using a 2.6F Carnelian HF-S microcatheter as an intraspinal canal platform catheter and review related literature.

CASE PRESENTATION

A 50-year-old man presented with a subarachnoid haemorrhage due to cervical spinal cord AVM. Diagnostic vertebral angiography revealed the AVM supplied by the PSA originated from the right C2 segmental artery and ASA arising from the right V4 segment. Superselective angiography for each feeder was achieved through a 2.6F Carnelian HF-S microcatheter, and a prenidal ASA aneurysm was diagnosed, which was clinically consistent with haemorrhagic origin. A 1.6F Carnelian MARVEL S microcatheter was cannulated into the aneurysm through the 2.6F Carnelian HF-S microcatheter positioned at the ASA. The aneurysm coiling was successfully performed without system instability or periprocedural complications.

CONCLUSIONS

Only a few cases have described endovascular treatment for spinal artery aneurysms. To date, no reports have been published regarding the use of an intraspinal canal platform catheter to treat spinal artery aneurysms. A 2.6F Carnelian HF-S microcatheter served as a useful intraspinal canal platform catheter for coil embolization of the ASA aneurysm. This system can provide excellent accessibility and controllability for endovascular treatment of spinal artery lesions.

Left Transradial Access Using a Radial-Specific Neurointerventional Guiding Sheath for Coil Embolization of Anterior Circulation Aneurysm Associated With the Aberrant Right Subclavian Artery: Technical Note and Literature Review

BACKGROUND

Aberrant right subclavian artery (ARSA) is a rare condition, but the most common anomaly of the aortic arch. Although neurointerventions via transradial access (TRA) are becoming increasingly popular worldwide, transradial carotid cannulation has been extremely challenging in patients with an ARSA. Herein, we present a case of ARSA-associated anterior communicating artery (ACoA) aneurysm that was successfully treated with a radial-specific 6F Simmons guiding sheath via left TRA. We also review the relevant literature.

METHODS

A 68-year-old-woman who was diagnosed as having an ARSA-associated ACoA aneurysm underwent simple coiling via left TRA. After the 6F Simmons guiding sheath was engaged into the right common carotid artery using the pull-back-technique, transradial quadraxial system (6F Simmons guiding sheath/6F intermediate catheter/3.2F intermediate catheter/coil-delivery microcatheter) was implemented.

RESULTS

Simple coiling of the aneurysm was successfully achieved without catheter kinking or system instability. The postprocedural course was uneventful. A follow-up magnetic resonance angiography showed no evidence of recanalization 1 years 9 months after the procedure.

CONCLUSIONS

Transradial anterior circulation intervention has been rarely used for patients with an ARSA due to unfavorable catheter trajectory. Left TRA using the 6F Simmons guiding sheath is a useful treatment option to address anterior circulation interventions for patients with an ARSA. Preoperative diagnosis of ARSA is necessary for the application of our method.

Smaller diameter sheaths are required to safely perform transradial neurointerventions

We read with great interest the paper titled "Transradial access with Simmons guiding catheter for carotid artery stenting: Feasibility and procedural complications in a single-center experience" by Muszynski et al. The authors concluded that a transradial carotid artery stenting (CAS) using a Glidesheath Slender 7F Introducer/7F Envoy Simmons 2 catheter system was feasible with a high procedural success rate and low access site complication rate. We completely agree with their conclusions. In this study, large-diameter sheaths were used. Large sheaths increase the risk of developing radial artery spasms. Interventionalists must be aware that radial artery spasm can not only require an access crossover, but can also cause severe access site complications, such as eversion or avulsion of the radial artery, catheter/sheath entrapment, and compartment syndrome. A 6F Simmons guiding sheath has a smaller outer diameter than the Glidesheath Slender 7F Introducer does, and it offers a large-bore working channel compatible with a 10-mm diameter Wallstent and Acculink. Transradial CAS with a 6F Simmons guiding sheath has previously yielded a high procedural success rate without serious access site complications. Nevertheless, we believe that a further decrease in the sheath diameter is required to safely perform transradial neurointerventions in more patients.

The efficacy of a visiting surgical service versus that of a hospital-based surgical service in providing endoscopic endonasal surgery to remove nonfunctioning pituitary adenomas in rural communities

PURPOSE

To satisfy the increasing demand for endoscopic endonasal approach (EEA) to treat pituitary tumors, especially in rural areas, the "mobile EEA" system, a visiting surgical service, has been established We report this unique system for maintaining community healthcare and evaluate the surgical results of mobile EEA.

METHODS

A retrospectively acquired database of 225 consecutive cases of EEA at Shinshu University Hospital (i.e., "home EEA") and its affiliated hospitals (i.e., "away EEA") between May 2018 and May 2022 was reviewed. A total of 105 consecutive patients who fulfilled the criterion of a diagnosis of new-onset nonfunctioning pituitary adenoma (PA) were included. Clinical characteristics and postoperative clinical outcomes were statistically compared between the home EEA and away EEA groups to assess the presence of a home advantage and/or an away disadvantage.

RESULTS

Patients were stratified into two cohorts: patients treated at our hospital (home EEA: n = 41 [39.0%]) and those treated in the visiting surgical service at an affiliated hospital (away EEA: n = 64 [61.0%]). Postoperative clinical outcomes, such as the extent of tumor resection (p = 0.39), operation time (p = 0.80), visual function (p = 0.54), and occurrence of surgical complications (p = 0.53), were comparable between the groups. There were no visiting surgical service-related adverse events or accidents caused by physicians' driving to away hospitals.

CONCLUSION

Pituitary surgeries performed via the mobile EEA system for nonfunctioning PAs may help maintain local community healthcare. Furthermore, this system can also contribute to the efficient training of surgeons by the same experienced pituitary surgeon using the same protocol.

Surgical trapping of a cavernous carotid aneurysm causing carotid cavernous fistula after flow diverter placement: Technical note and literature review

BACKGROUND

Flow diverter (FD) treatment is a promising therapeutic strategy for intracranial aneurysms such as cavernous carotid aneurysms (CCAs). Direct cavernous carotid fistula (CCF) caused by delayed rupture of FD-treated CCAs has been reported, and endovascular therapy has been used in the literature. Surgical treatment is warranted for patients who have failed or ineligible for endovascular treatment. However, no studies have evaluated surgical treatment to date. Here, this paper presents the first case of direct CCF due to delayed rupture of an FD-treated CCA managed with surgical internal carotid artery (ICA) trapping with bypass revascularization, in which the intracranial ICA with FD placement was successfully occluded with aneurysm clips.

CASE PRESENTATION

A 63-year-old man with a diagnosis of large symptomatic left CCA underwent FD treatment. The FD was deployed from the supraclinoid segment of the ICA distal to the ophthalmic artery to the petrous segment of the ICA. Since angiography 7 months after the FD placement showed progressive direct CCF, left superficial temporal artery-middle cerebral artery bypass followed by ICA trapping was performed. The intracranial ICA proximal to the ophthalmic artery where the FD was placed was successfully occluded using two aneurysm clips. The postoperative course was uneventful. Follow-up angiography 8 months after the surgery confirmed complete obliteration of the direct CCF and CCA.

CONCLUSION

The intracranial artery in which the FD was deployed was successfully occluded with two aneurysm clips. ICA trapping can be a feasible and useful therapeutic option to treat direct CCF caused by FD-treated CCAs.

A rare pure intraventricular hemorrhage caused by ruptured internal carotid artery-anterior choroidal artery aneurysm: a case report and literature review

Although intraventricular hemorrhage (IVH) frequently develops secondary to intraparenchymal or subarachnoid hemorrhage, pure IVH-non-traumatic spontaneous intracranial hemorrhage confined to the cerebral ventricular system-is rare. Moreover, pure IVH caused by ruptured proximal aneurysm is an extremely rare but life-threatening condition. Herein, we present a case of pure IVH due to a ruptured internal carotid artery -anterior choroidal artery (ICA-AChA) aneurysm and review related literature. A 77-year-old man presenting with altered mental status was hospitalized due to a massive pure IVH with ventriculomegaly. The patient was conservatively managed because his consciousness level improved. On the following day, computed tomography angiography revealed a right ICA-AChA aneurysm embedded in the temporal lobe adjacent to the anterior part of the inferior horn of the lateral ventricle, which was consistent with the hemorrhagic origin. Coil embolization of the aneurysm was successfully performed, and the postprocedural course was uneventful. To date, only a few cases have described pure IVH caused by a ruptured proximal aneurysm. If the ruptured proximal aneurysm remains unnoticed, catastrophic rehemorrhage may occur. Aneurysm obliteration should precede the treatment of acute hydrocephalus. Neurosurgeons/neurointerventionalists must be aware about pure IVH caused by a ruptured proximal aneurysm even if it rarely occurs.

Brain metastasis of chondrosarcoma: A case report and literature review

Brain metastases of a chondrosarcoma are extremely rare, and treatment remains controversial. A 54-year-old woman had undergone surgical treatment for a femoral chondrosarcoma and its lung metastases. She presented with visual disturbance and dizziness 22 months after the initial surgery; imaging studies of the brain revealed a metastatic tumor in the left parieto-occipital lobe. Surgical tumor resection was performed; however, only 2 months after gross total resection of the tumor, rapid tumor recurrence was observed. Surgical resection was performed again, followed by intensity-modulated radiation therapy. Three months later, another small brain lesion was detected in the right parietal lobe and was treated with gamma knife stereotactic radiosurgery. No recurrence has been reported 20 months after this radiosurgery for brain metastasis. Thus, surgical treatment combined with several adequate radiation therapy sessions may be a viable treatment strategy for brain metastases of chondrosarcomas.

Real-time angiography in endovascular revascularization of intracranial atherosclerotic internal carotid artery stenosis under proximal balloon protection: "Retrograde suction-injection" technique and literature review

Intracranial angioplasty/stenting is a treatment option for patients with symptomatic intracranial atherosclerotic disease refractory to aggressive medical treatment. However, it carries a risk of procedure-related embolism as well as reperfusion hemorrhage and in-stent thrombosis. We have devised a new embolic protection system which can achieve both total ipsilateral internal carotid artery (ICA) embolic protection and real-time visualization of the target lesion during endovascular revascularization of intracranial atherosclerotic disease below the carotid T junction. Herein, we describe a case of medically refractory symptomatic intracranial atherosclerotic ICA stenosis successfully treated with this method.

Transradial Mechanical Thrombectomy Using a Radial-specific Neurointerventional Guiding Sheath for Anterior Circulation Large-Vessel Occlusions: Preliminary Experience and Literature Review

BACKGROUND

Transradial mechanical thrombectomy (MT) is increasingly used because it is associated with a low incidence of vascular access site complications. However, transradial carotid cannulation can be technically challenging to perform in patients with an unfavorable supra-aortic takeoff. In this study, the feasibility and safety of a new transradial MT system with a radial-specific neurointerventional guiding sheath-6F Simmons guiding sheath was evaluated-in patients with anterior circulation large-vessel occlusions. Additionally, a literature review was performed.

METHODS

We retrospectively analyzed data from our institutional database about consecutive patients who underwent transradial MT for anterior circulation large-vessel occlusion. After the 6F Simmons guiding sheath was engaged into the target common carotid artery, a triaxial system (Simmons guiding sheath/aspiration catheter/microcatheter), was established. MT using the continuous aspiration prior to intracranial vascular embolectomy technique was performed. Then, procedural success rate, successful revascularization, and procedure-related complications were assessed.

RESULTS

A total of 13 patients who had transradial MT were included in the analysis. All 13 patients underwent successful thrombectomy without catheter kinking or system instability, and 12 of them achieved successful revascularization (modified Thrombolysis in Cerebral Infarction score of ≥2b). No complications occurred.

CONCLUSIONS

To the best of our knowledge, this is the first case series on transradial MT using a radial-specific neurointerventional system for anterior circulation large-vessel occlusions. This method may increase the success rate of transradial MT. Based on our initial experience, transradial MT, using this system, was feasible and safe for anterior circulation large-vessel occlusions.

Real-Time Monitoring of Aneurysm Catheterization During Stent-Assisted Coiling for Irregularly Shaped Intracranial Aneurysms: The Scope Technique

OBJECTIVE

Stent-assisted coiling (SAC) using the jailing technique is a well-established treatment for wide-neck intracranial aneurysms. However, low-volume packing, which is a key factor for aneurysm recanalization, can occur in patients with irregularly shaped aneurysms. We have devised a real-time monitoring system for aneurysm catheterization that allows the intentional placement of the jailed coil-delivery microcatheter and deployed stent, referred to as the "scope" technique. Herein, we present a case of irregularly shaped anterior communicating artery (ACoA) aneurysm successfully treated with SAC using this technique.

METHODS

A 72-year-old woman diagnosed with an unruptured wide-neck ACoA aneurysm that was eccentric to the parent ACoA and overhanging posteriorly underwent SAC using this technique. Bilateral transradial quadraxial systems (6-Fr Simmons guiding sheath/6-Fr intermediate catheter/3.2-Fr intermediate catheter/microcatheter) were established via right and left internal carotid artery. The stent-delivery microcatheter was advanced into the left A2 via the right A1, leaving a 0.014″ microguidewire for visualization under fluoroscopic guidance. To place the coil-delivery microcatheter in the middle of the aneurysm after stent deployment, the coil-delivery microcatheter was cannulated into the aneurysm via the left A1, intendedly through the posterior side of the stent-delivery microcatheter in the down-the-barrel view of the parent ACoA (the scope technique).

RESULTS

After stent deployment, SAC of the aneurysm was successfully achieved.

CONCLUSIONS

Using this technique, the coil-delivery microcatheter was cannulated into the aneurysm, while monitoring its positional relationship with the stent-delivery microcatheter in real time. This technique is a useful treatment option for irregularly shaped and wide-neck aneurysms.

Single-lane clipping technique for a ruptured aneurysm of A1 fenestration of the anterior cerebral artery: a case report and literature review

Fenestration of the A1 segment of the anterior cerebral artery is a rare vascular anomaly with a high risk of saccular aneurysm at the proximal end of the A1 fenestration. These aneurysms have a high risk of rupture. However, conventional surgical clipping can be technically challenging due to the anatomical characteristics. We report a case of A1 fenestration with a ruptured aneurysm wherein we successfully achieved complete obliteration of the aneurysm with a new "single-lane" clipping technique. A 64-year-old woman presented with a ruptured saccular A1 aneurysm at the proximal end of an A1 fenestration, resulting in subarachnoid hemorrhage. Microsurgical clipping was attempted; however, adequate exposure of the aneurysm could not be achieved. The recurrent artery of Heubner originated near the distal end of the lateral limb of the A1 fenestration. The lateral limb of the A1 fenestration had no perforating arteries, according to surgical examination. Thus, the aneurysm neck and lateral limb were concurrently obliterated using a nonfenestrated clip, preserving the medial limb of the A1 fenestration. The antegrade flow of the recurrent artery of Heubner was detected using the retrograde flow of the distal part of the lateral limb of the A1 fenestration during intraoperative indocyanine green video angiography. The postoperative course was uneventful without any evidence of ischemic stroke. For A1 aneurysms arising from the proximal end of the A1 fenestration, this technique may be a useful treatment option. Before using this technique, careful surgical exploration should be performed to assess the A1 perforating arteries.

Transorbital penetrating head injury by a wooden chopstick in the cavernous sinus: a case report and literature review

Penetrating head injury is a relatively rare condition associated with high morbidity and mortality. Although the immediate treatment of penetrating head injury is needed, surgical strategies are varied based on the trajectory of the penetrating objects in the cranium. We present a case of 24-year-old man who sustained a transorbital penetrating injury caused by a wooden chopstick. Neuroimages revealed a linear lesion extending from the left intraorbital segment to the cavernous sinus passing through the superior orbital fissure. The foreign body was successfully removed via the transcranial approach without complications. A careful management based on the perioperative images and correct diagnosis is necessary to avoid unfavorable complications. Four cases of transorbital penetrating injuries have been previously reported, in which the foreign body penetrated through the superior orbital fissure and lodged in the cavernous sinus. The frontotemporal craniotomy with extradural approach can be a useful option to remove foreign bodies around the cavernous sinus regions.

Surgical revascularization for quasi-moyamoya disease associated with polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome: a case report and literature review

POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome is a rare multisystem disease characterized by plasma cell dyscrasia and overproduction of vascular endothelial growth factor, which is related to disease activity. Recent treatment strategies have improved survival of patients suffering from this disorder; however, ischemic stroke remains a poor prognostic factor. POEMS patients with ischemic stroke frequently develop cerebral large artery stenosis/occlusion, followed by progressive stroke. Post literature review, we present an ischemic stroke case of quasi-moyamoya disease linked with this syndrome that was successfully treated with surgical revascularization. A 41-year-old woman diagnosed with POEMS syndrome developed progressive ischemic stroke due to quasi-moyamoya disease, despite decreased vascular endothelial growth factor level with lenalidomide and dexamethasone treatment. She underwent superficial temporal artery to middle cerebral artery bypass with encephalo-duro-myo-synangiosis bilaterally. The postoperative course was uneventful. Two years and five months after the stroke, neuroimaging demonstrated bypass patency, neovascularization after encephalo-duro-myo-synangiosis, and no recurrence of stroke. Our case is the first to report successful surgical revascularization for a POEMS patient. Surgical revascularization may be a useful treatment option for patients with quasi-moyamoya disease associated with POEMS syndrome, especially for those who develop refractory ischemic stroke despite reduced vascular endothelial growth factor level.

Postoperative Intratumoral or Peritumoral Hematomas After Vestibular Schwannoma Resection

BACKGROUND

Surgical removal of a vestibular schwannoma is a complex and challenging procedure, which may be complicated by development of postoperative hematomas, particularly after incomplete resection of the tumor.

OBJECTIVE

To investigate the occurrence of postoperative intra- or peritumoral hematomas after surgery for a vestibular schwannoma.

METHODS

This retrospective study evaluated 49 patients (age range 17-78 years) with a vestibular schwannoma, who were treated surgically via the lateral suboccipital approach between 2011 and 2016. The tumors ranged in size from 0 mm (in a case of an intracanalicular lesion) to 56 mm. In 30 cases (61%), total or near-total resection was accomplished, and in 19 cases (39%), subtotal or partial resection was done. On the basis of their bleeding tendency during tumor removal, the patients were divided into a "less-bleeding" (38 cases; 78%) and a "more-bleeding" (11 cases; 22%) subgroups.

RESULTS

A maximal vestibular schwannoma diameter >30 mm, patient age >60 years, and more bleeding during tumor removal were significantly associated with incomplete (subtotal or partial) resection. In six cases (12%), serial computed tomography after surgery demonstrated a postoperative hematoma, which was caused by insufficient irrigation of the surgical field (in two cases) or resulted from peritumoral hemorrhage (in two cases), intratumoral hemorrhage (in one case), or both intra- and peritumoral hemorrhage (in one case). The latter patient required urgent reoperation. In all cases, postoperative hematomas occurred after incomplete (subtotal or partial) resection of a vestibular schwannoma, and their development was significantly associated with more bleeding during tumor removal.

CONCLUSION

For avoidance of postoperative hematomas, careful hemostasis is required after completion of vestibular schwannoma removal, especially in cases with incomplete resection and an excessive bleeding tendency of the tumor tissue.

The Current Status in Intraoperative Image-Guided Neurosurgery Associated with Progressive Operating Rooms: A Retrospective Analysis

OBJECTIVE

Shinshu University Hospital has advanced operating rooms including a mobile computed tomography (mCT) room, Smart Cyber Operating Theater (SCOT) with intraoperative magnetic resonance imaging, hybrid operating room (hOR) with intraoperative image-guided surgery, and conventional operating rooms. We investigated the characteristics of cases assigned to each operating room.

METHODS

Five hundred forty neurosurgery cases from January 2018 to April 2021 were analyzed. We analyzed the selection of operating room according to pathology, surgical device requirement, and urgency, and we examined associations between operating room characteristics and these factors.

RESULTS

Neurological surgeries were performed in an mCT room, an hOR, a SCOT, and a conventional operating room in 333 (61.7%), 64 (11.9%), 49 (9.1%), and 94 (17.4%) cases, respectively. mCT rooms were more frequently selected than other rooms for vascular/extra-axial tumors, which have a lower need for intraoperative image guidance. Spinal surgeries with segment diagnosis or intraoperative bone removal tended to be performed in the hOR. The rate of SCOT use tended to be higher for intra-axial tumors with poorly circumscribed borders than for vascular/extra-axial tumors. Endoscopic procedures were more frequently performed in the SCOT and mCT rooms than in hORs and conventional operating rooms. Emergency surgeries were often performed in the conventional operating rooms, even in cases where SCOT and hOR seemed suitable.

CONCLUSIONS

Intraoperative image-guided surgeries were performed according to the characteristics of each operating room best suited for various diseases and operative methods. Further research is needed to prove whether operating room selection improves neurosurgical outcomes.

＜Editors' Choice＞ Surgical removal of an intracranially migrated acupuncture needle: a case report and literature review

Acupuncture is a popular alternative therapy worldwide and is generally safe. However, serious acupuncture-related complications can occur. Intracranial complications caused by a migrated acupuncture needle are extremely rare. Herein we report a surgical case of intracranial acupuncture needle migration and discuss the key technical aspects of the procedure. We additionally performed a review of the relevant literature. A 55-year-old woman presented with migration of a broken acupuncture needle via the posterior cervical skin. Computed tomography (CT) showed that the needle migrated intra- and extradurally via the atlanto-occipital junction. CT angiography revealed that the needle tail was located adjacent to the right distal horizontal loop of the vertebral artery. Meanwhile, the needle tip was positioned in the premedullary cistern adjacent to the medulla oblongata via the right lateral medullary cistern. Emergent surgical removal was conducted. Intradural exploration was required as the needle was not found in the epidural space. The needle penetrated the adventitia of the right intradural vertebral artery. We failed to pull out the needle toward the epidural space. After the needle was completely pulled into the intradural space, it was successfully removed without bleeding complication. Postoperative CT showed no evidence of residual needle fragment. The patient was discharged home without any sequelae. To the best of our knowledge, this is the first case of penetrating vertebral artery injury caused by radiologically confirmed acupuncture needle migration. An intracranially migrated needle should be removed urgently to prevent further migration causing brainstem, cranial nerve, and vessel injuries. The surgical strategy should be selected according to needle location and direction.

New distal balloon protection system for transradial carotid artery stenting after the PercuSurge GuardWire withdrawal: The jailbreak technique

BACKGROUND

Embolic protection devices are commonly used to prevent cerebral embolism during carotid artery stenting (CAS). However, the PercuSurge Guardwire device (Medtronic, Minneapolis, MN, USA), a distal balloon protection device, was discontinued in April 2021. We present a case of successful CAS using a new distal balloon protection system. The procedure, referred to as the jailbreak technique, was performed via transradial access (TRA).

CASE PRESENTATION

A 67-year-old man underwent CAS, using the jailbreak technique, for right carotid stenosis with a vulnerable plaque. 6F and 4F Simmons guiding sheaths were delivered into the right common carotid artery via the right and left TRA, respectively. Distal balloon protection was provided using a 2.6F dual-lumen balloon microcatheter (Pinnacle Blue 20, Tokai Medical Products, Aichi, Japan) via the 4F Simmons guiding sheath. A 4.2F catheter was coaxially delivered proximal to the balloon and distal to the lesion. After CAS was successfully performed via the 6F Simmons guiding sheath, the Pinnacle Blue 20 was retrieved through the 4.2F catheter without interfering with the distal stent flare and stent struts. Postprocedural neuroimaging revealed no evidence of ischemic stroke.

CONCLUSIONS

The jailbreak technique allows distal balloon protection during transradial CAS. This is a useful treatment option for patients with carotid stenosis.

Sequential Development of Putaminal Hemorrhage and Corona Radiata Infarction in the Same Lenticulostriate Arterial Territory

Putaminal hemorrhage is a common type of spontaneous cerebral hemorrhage. However, to our knowledge, there have been no reports of sequential cerebral hemorrhage and infarction in the same perforating arterial territory. Herein, we present the first reported case of the sequential development of putaminal hemorrhage and corona radiata infarction in the same lenticulostriate arterial (LSA) territory. Early intensive blood pressure lowering treatment may have aggravated ischemic damage. If a patient presents with motor weakness that cannot be explained by putaminal hemorrhage, the sequential development of corona radiata infarction in the same LSA territory should be ruled out.

Cerebral Edema Due to Chemotherapeutic Wafer Implantation for Malignant Glioma: Registry Study of Correlation with Perioperative Epileptic Seizures

Factors predicting adverse events following implantation with wafers containing 1,3-bis (2-chloroethyl) -1-nitrosourea (carmustine, BCNU), which is used in local chemotherapy for malignant gliomas (MGs), are unknown. The association between cerebral edema (CE), which often occurs after implantation, and perioperative seizures, which are often observed in MG cases, is under debate. This study investigated risk factors for CE associated with BCNU wafer implantation and their relationship with perioperative seizures. A total of 31 surgical cases involving 28 adult patients who underwent BCNU wafer implantation for MGs were investigated and classified into those with and without postoperative transient CE. We assessed the correlations between CE caused by BCNU implantation and various factors, including postoperative epileptic seizures. World Health Organization (WHO) grade III MGs significantly affected postoperative CE (p = 0.003) and the occurrence of seizures (p = 0.0004). Factors predictive of postoperative seizures were WHO grade III MGs (p = 0.0026), increased postoperative CE (p = 0.0272), and history of preoperative seizures (p = 0.0316). Postoperative CE, WHO grade III MGs, and a history of preoperative seizures might predict the postoperative occurrence of seizures, necessitating stringent management of seizures and CE in the affected patients.

Evaluation of the nutrient foramen as a suitable landmark in spinal surgery

BACKGROUND CONTEXT

The posterior cervical approach is a very popular surgical procedure. Because of the slope-shaped laminae, a suitable landmark for laminectomy, laminoplasty, and pedicle screw placement does not exist.

PURPOSE

We investigated the association between the nutrient foramen and spinal canal, and the safety of bone gutter placement using nutrient foramina for safe and effective spinal surgery.

STUDY DESIGN

Observational SETTING: University Hospital PATIENT SAMPLES: Two hundred and sixty-six consecutive patients treated for cervical pathologies in our university hospital between January 2005 and December 2019.

OUTCOME MEASURES

We identified the location of nutrient foramina and their anatomical association with the spinal canal using preoperative three-dimensional CT scanning.

METHODS

We studied the distance between each foramen and the spinal canal, and the angle of the nutrient foramen at each vertebral level.

RESULTS

The nutrient foramina were always located outside the spinal canal, with an average distance of +3.06±1.74 mm. The lower the spinal level, the closer the nutrient foramen to the spinal canal.

CONCLUSIONS

The nutrient foramen can be considered a reliable landmark when using the posterior cervical approach.

A preliminary study of the diagnostic efficacy and safety of the novel boring biopsy for brain lesions

Existing methods for biopsy of intraparenchymal brain lesions, including stereotactic biopsy and open block biopsy, have advantages and disadvantages. We propose a novel biopsy method, called “boring biopsy,” which aims to overcome the drawbacks of each conventional method. This method is less invasive and allows obtaining continuous specimens of sufficient volume. We aimed to assess the feasibility and efficacy of using boring biopsy for intraparenchymal brain lesions. We included 26 consecutive patients who underwent boring biopsy for intraparenchymal lesions. Columnar continuous specimens from the surface of the normal brain tissue to the tumor margin and the center of the lesion were obtained using the boring biopsy method. We used a catheter introducer with original modifications to create a cylindrical biopsy tool for surgery. Columnar continuous specimens were successfully obtained. Histopathological diagnosis was based on cellular changes and differentiation from normal tissues to the core of the lesion and established in all cases. No permanent deficits, major adverse outcomes, or deaths were observed. This novel technique may improve diagnostic accuracy and reduce invasiveness associated with brain biopsy. This method may become the next standard procedure, particularly in some cases where histological evaluation is paramount, and conventional biopsy methods are not suitable.

Intraoperative Image-Guided Surgery for Gliomas in the Smart Cyber Operating Theater (SCOT®): A Preliminary Clinical Application

BACKGROUND

Various devices exist for glioma image-guided surgery to improve tumor resection. These devices work as standalone units, making the flow of operative information complicated and disjointed. A novel networked operating room, the "Smart Cyber Operating Theater (SCOT®)," has been developed, integrating standalone medical devices using the "OPeLiNK®" communication interface. Herein, we report and evaluate the impact of the SCOT® for glioma surgery and our initial experiences.

METHODS

Patients with gliomas who underwent tumor resection in the SCOT® between July 2018 and June 2021 were retrospectively reviewed. Various types of intraoperative information were integrated, managed, and shared with the surgical strategy desk using the OPeLiNK®. Patients' demographics, tumor characteristics, treatment details, and outcomes were obtained. The impact of the SCOT® system was evaluated.

RESULTS

Twenty-seven patients with a mean age of 48.6 years (range 13 - 88 years) met the inclusion criteria. We successfully completed all the surgical procedures using the SCOT®. The mean operation time was 420.6 minutes (225 - 667 min). Gross total resection was accomplished in 13 patients (48.1%), subtotal resection in 4 (14.8%), and partial resection in 10 (37.0%). The main surgeon in the operating room and other neurosurgeons at the strategy desk shared and discussed the information in real time during the procedures.

CONCLUSIONS

The use of the SCOT® was demonstrated to be safe and feasible in glioma surgery. This study suggests that the SCOT® may improve surgical outcomes and educational impact by sharing information in real-time with the strategy desk.

Correlations Among Consistency, Computed Tomography Values, and Histopathological Subtypes of Spinal Meningioma

The consistency of spinal meningiomas is important to consider when performing tumor removal surgery. This study evaluated the correlations between spinal meningioma consistency and both preoperative computed tomography (CT) values and histopathological subtypes. Fifteen consecutive patients who underwent surgical resection of spinal meningioma at our institution were identified, and preoperative CT values and the signal intensity of T2-weighted magnetic resonance images of the tumor were determined retrospectively. The consistency of the spinal meningioma was defined based on the ultrasonic surgical aspirator output during tumor debulking. Patients were assigned to 2 groups: a soft group (n=4) and a hard group (n=11). The T2 signal intensity was significantly higher in the soft group than in the hard group (p=0.001). While the CT values were considerably higher in the hard group, the difference was not significant (p=0.19). Regarding the histopathological subtypes, psammomatous meningioma exhibited significantly higher CT values than meningothelial meningioma (p=0.019); however, there was a higher frequency of hard tumors in meningothelial meningioma cases than in psammomatous meningioma cases. Although neither robust correlations between tumor consistency and CT values nor a relationship between tumor consistency and histopathological subtype has been established, these results might help with the perioperative manegement of spinal tumors.

Comparison Between Conventional Flash and Off-Response Intraoperative Visual Evoked Potential Monitoring for Endoscopic Endonasal Surgery

BACKGROUND

Intraoperative flash stimulation visual evoked potential (VEP) monitoring has been used for endoscopic endonasal approach (EEA). Recently, off-response VEP, which is recorded when the light stimulus is turned off, was introduced to monitor visual function intraoperatively.

OBJECTIVE

To evaluate off-response VEP monitoring in comparison with the conventional flash stimulation VEP monitoring for EEA.

METHODS

From March 2015 to March 2020, 70 EEA surgeries with intraoperative VEP monitoring (140 eyes) were performed. Light stimuli were delivered by a pair of goggle electrodes. Recording electrodes were placed on the scalp over the occipital region. The warning signal was prompted by a reduction of the peak-to-peak amplitude of the VEP by more than 50% compared to the initial amplitude. Visual function was assessed pre- and postoperatively. Results of flash and off-response VEP monitoring were compared.

RESULTS

VEP was recorded in 134 eyes. Warning signal occurred in 23 eyes (transient in 17 eyes and permanent in 6 eyes). Two eyes showed permanent VEP attenuation for flash VEP monitoring, in which one patient had postoperative visual function deterioration. Four eyes showed permanent VEP attenuation for off-response VEP monitoring, where 2 patients had postoperative visual function deterioration. Sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 98.9%, 50%, and 100%, respectively, for flash stimulation VEP, and 100%, 97.8%, 50%, and 100%, respectively, for off-response VEP.

CONCLUSION

VEP monitoring was useful to monitor visual function in EEA surgery. Off-response VEP monitoring was not inferior to conventional flash stimulation VEP monitoring.

Transradial quadraxial system for coil embolization of distal anterior cerebral artery aneurysms: A radial-first center case series and literature review

PURPOSE

Endovascular treatment is technically challenging as distal anterior cerebral artery (DACA) aneurysms have distal location, small-caliber parent artery, and small size/wide neck. This study evaluated the feasibility and safety of the transradial approach (TRA) with a radial-specific neurointerventional guiding sheath as the first-line technique for DACA aneurysms.

METHODS

We retrospectively analyzed an institutional database of consecutive patients with DACA aneurysm who underwent coil embolization using TRA. Ten consecutive patients were included in this study. After the radial-specific 6F Simmons guiding sheath (0.088″ inner diameter) was completely engaged into the target common carotid artery, a quadraxial system (6F Simmons guiding sheath/6F intermediate catheter/3.2F intermediate catheter/single microcatheter) was used for embolization. Then, we assessed for procedural success, angiographic outcomes, and procedure-related or vascular access site complications.

RESULTS

Embolization procedures were conducted using simple coiling in eight and stent-assisted coiling with the trans-cell approach in two patients. The embolization procedure was successful in all patients (n = 10). Moreover, none presented with catheter kinking, parent artery flow stagnation, or system instability during the procedure. Immediate postprocedural angiography revealed complete obliteration in six and residual neck in four patients. Then, eight patients underwent follow-up angiography at a mean of 7.1 months, and none developed recanalization or required retreatment. The postprocedural course was uneventful, and there were no complications.

CONCLUSION

The transradial quadraxial system had the ability to achieve sufficient stability and kink resistance in DACA aneurysm embolization. Thus, this method was feasible and safe and had a high success rate.

Endoscopic diving technique for surgery of brain abscess

BACKGROUND

Recent advances in neuroendoscopic surgery have led to the minimally invasive treatment of brain abscesses using various endoscopy techniques. The endoscopic diving technique (EDT) involving the formation of fluid lenses to improve the visibility of the endoscope has been reported to be useful in the endoscopic endonasal approach (EEA) for pituitary and midline cranial base lesions. Here, we report a case of brain abscess treated endoscopically using EDT in cylinder surgery.

CLINICAL PRESENTATION

A 29-year-old man with 11q trisomy syndrome developed a fever and progressive right hemiparesis was observed. A diagnosis of a brain abscess was made based on neuroradiological imaging, and endoscopic irrigation and drainage with EDT via a transparent endoscopic sheath were performed, which provided a clear operative field and allowed satisfactory irrigation without bacterial contamination. The bacterium identified by PCR was Streptococcus intermedius, and antibiotic therapy was administered. Postoperatively, his symptoms gradually improved.

CONCLUSION

This is the first technical case report describing the clinical experience of EDT in brain abscess surgery. EDT may be a useful technique not only in EEA but also in cylinder surgery for brain abscesses.

Effectiveness of the intraoperative magnetic resonance imaging during endoscopic endonasal approach for acromegaly

PURPOSE

Acromegaly is an acquired disorder usually caused by growth hormone-secreting pituitary adenoma, resolution of which requires correction of the excess hormone production. Recently, intraoperative magnetic resonance imaging (iMRI) was reported to be useful during the endoscopic endonasal approach (EEA) for pituitary adenoma. The present study was performed to quantitatively assess the role of iMRI in improving surgical outcomes in EEA for acromegaly.

METHODS

Twenty surgeries for acromegaly in EEA performed at Shinshu University Hospital between April 2016 and March 2020 were reviewed retrospectively. The inclusion criteria were cases without severe cavernous sinus tumor invasion (Knosp grade 0 - 3) or history of prior pituitary surgery. Fifteen consecutive patients were enrolled in this study. Clinical characteristics and postoperative clinical outcomes were compared between patients with and without use of iMRI during EEA for acromegaly.

RESULTS

Conventional navigation-guided surgery was performed in nine patients, and six underwent iMRI-guided EEA for acromegaly. Gross total resection (GTR) was obtained in the six (100%) patients in the iMRI group, and in four (44.4%) patients in the conventional group without iMRI. Postoperative clinical outcomes, including hormonal remission rate and surgical complications, were comparable between the two groups.

CONCLUSION

Although iMRI significantly increased the GTR rate, we found no direct evidence of increased hormonal remission rate by use of iMRI. It is important to confirm complete tumor resection carefully with not only iMRI findings, but also with intraoperative high-definition endoscopic direct visualization to increase the hormonal remission rate of acromegaly.

Intraoperative low-field magnetic resonance imaging-guided tumor resection in glioma surgery: Pros and cons

BACKGROUNDIntraoperative magnetic resonance imaging (MRI) is useful for identifying residual tumors during surgery. It can improve the resection rate; however, complications related to prolonged operating time may be increased. We assessed the advantages and disadvantages of using low-field intraoperative MRI and compared them with non-use of iMRI during glioma surgery.METHODSThe study included 22 consecutive patients who underwent total tumor resection at Shinshu University Hospital between September 2017 and October 2020. Patients were divided into two groups (before and after introducing 0.4-T low-field open intraoperative MRI at the hospital). Patient demographics, gross total resection (GTR) rate, postoperative neurological deficits, need for reoperation, and operating time were compared between the groups.RESULTSNo significant differences were observed in patient demographics. While GTR of the tumor was achieved in 8/11 cases (73%) with intraoperative MRI, 2/11 cases (18%) of the control group achieved GTR (p=0.033). Seven patients had transient neurological deficits: 3 in the intraoperative MRI group and 4 in the control group, without significant differences between groups. There was no unintended reoperation in the intraoperative MRI group, except for one case in the control group. Mean operating time (465.8 vs. 483.6 minutes for the intraoperative MRI and control groups, respectively) did not differ.CONCLUSIONSLow-field intraoperative MRI improves the GTR rate and reduces unintentional reoperation incidence compared to the conventional technique. Our findings showed no operating time prolongation in the MRI group despite intraoperative imaging, which considered that intraoperative MRI helped reduce decision-making time and procedural hesitation during surgery.

Pediatric Case of Life-Threatening Stroke Caused by Reversible Cerebral Vasoconstriction Syndrome with Spontaneous Cervical Internal Carotid Artery Vasospasm: A Case Report

Pediatric reversible cerebral vasoconstriction syndrome (RCVS) and spontaneous cervical internal carotid artery (ICA) vasospasm are rare conditions; the former is commonly associated with a favorable prognosis. A healthy 13-year-old girl presented with thunderclap headache, followed by left hemiparesis, during a curling match. Six days after onset, left hemiparesis worsened to hemiplegia. Magnetic resonance imaging showed progressive cerebral infarction caused by severe right middle cerebral artery and cervical ICA stenosis. She became comatose because of impending uncal herniation. Emergent surgical decompression was performed. Then, 59 days after onset, her multiple stenoses improved, which was consistent with RCVS concomitant with spontaneous cervical ICA vasospasm. This is the first case of RCVS that concurrently developed spontaneous cervical ICA vasospasm. The patient developed life-threatening stroke due to the hemodynamic impairment of the affected intracranial and cervical arteries. Spontaneous extracranial supra-aortic artery vasospasm can be a poor prognostic predictor of RCVS.

Surgical strategy for symptomatic pineal cyst: is endoscopit third ventriculostomy necessary in addition to cyst fenestration?

Symptomatic large pineal cyst (PC) remains a rare entity. The stable natural course of asymptomatic PCs is well established. However, large cysts may cause pressure-related symptoms necessitating surgical intervention. The surgical strategy for symptomatic PCs is still controversial. Regardless of the approach, total resection of the cyst is not mandatory. The endoscopic approach allows cyst fenestration in patients with associated obstructive hydrocephalus. On the other hand, the necessity of simultaneous endoscopic third ventriculostomy (ETV) is still debatable. Here, we report a case of a woman who underwent endoscopic cyst fenestration, biopsy, and third ventriculostomy for a large symptomatic PC and discuss the surgical strategy. A 30-year-old woman presented with headache and diplopia, MRI showed a large PC and accompanying obstructive hydrocephalus. Simultaneous cyst fenestration, biopsy and ETV with endoscopy was successfully completed. She had an uneventful recovery period with immediate relief of symptoms. Although, the aqueduct was communicated due to cyst shrinkage, the patency of the third ventricular stoma was demonstrated in long-term follow-up scans. Based on clinical course of the present case, we concluded that ETV in addition to cyst fenestration should be considered necessary and beneficial in cases of large symptomatic PC with associated hydrocephalus whenever an endoscopic intraventricular approach is considered.

Microscopic Navigation-Guided Fence Post Technique for Maximal Tumor Resection During Glioma Surgery

BACKGROUND

The fence post technique, which involves insertion of catheters as fence posts around a tumor, has been widely used to demarcate the tumor border for maximal resection of intraparenchymal tumors, such as gliomas. However, a standard procedure for fence post insertion has not been established, and there are some limitations. To overcome this problem, a simple microscopic navigation-guided fence post technique was developed. The feasibility and efficacy of this novel technique during glioma surgery were assessed.

METHODS

The microscopic navigation-guided fence post technique was used in 46 glioma surgeries performed in 42 patients. Intraoperatively, the preplanned trajectory was overlaid on the microscopic surgical field, and the microscope angle was changed until the entry and target points of the trajectory overlapped. A fence post catheter was inserted as planned under microscopic view, and the tumor was resected with fence post guidance. Preoperative tumor characteristics and surgical outcomes were evaluated.

RESULTS

Mean age of patients was 50 years (range, 16-78 years), and 19 (45%) of 42 patients were women. Maximal safe resection was successfully achieved in 45 surgeries (97.8%), which was planned preoperatively with identification of the tumor border with fence posts without adverse effects of brain shift. No surgical complications attributable to fence post insertion occurred.

CONCLUSIONS

Clinical experience indicated that the microscopic navigation-guided fence post technique, in which fence posts can be placed without requiring the surgeon to take their eyes off the microscope, is safe and useful in glioma surgery.