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A 54-year-old woman with no relevant medical history presented with severe headache, nausea, and vomiting for 8 days. Imaging examination revealed a subarachnoid hemorrhage in the left interpeduncular cistern without aneurysms. Computed tomography angiography and digital subtraction angiography found an anomalous vein near the site of the hemorrhagic clots, indicating abnormalities in cerebral venous drainage that provided an anastomosis between the drainage system of the deep middle cerebral, petrosal, and lateral mesencephalic veins. In the primitive pattern, the basal vein of Rosenthal drains into the lateral mesencephalic vein and to the petrosal sinus. This anomalous flow may predispose to subarachnoid hemorrhage, emphasizing the association between nonaneurysmal perimesencephalic hemorrhage and venous anomalies., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: Trigeminal neuralgia (TN) due to venous compression is far less common than that due to arterial compression, and its pathogenesis is less clear. We investigated the clinical and imaging features of TN caused by solely venous compression by measuring the morphologies of the posterior cranial fossa (PCF) and the trigeminal nerve., Methods: We retrospectively reviewed records of TN patients who underwent microvascular decompression at our institution and extracted cases with solely arterial or solely venous compression. Preoperative magnetic resonance imaging was used to find the length (Y), width (X), height (Z), and volume (V) of the PCF, the angle between the trigeminal nerve and pons, and the distance between Meckel's cave and the root entry zone of the trigeminal nerve., Results: Of 152 patients, 24 had TN caused solely by venous compression. The value of Y was significantly smaller in the venous group than the arterial group (P < 0.01). The trigeminal nerve and pons was significantly smaller in the venous group (P < 0.01). We hypothesized that TN patients with solely venous compression had a characteristic PCF morphology with a short anteroposterior diameter (Y), such that age-related changes in brain morphology could alter the course of the trigeminal nerve and cause compression by a vein., Conclusions: The morphological features of the PCF differed between patients with TN of venous and those with TN of arterial etiology. Age-related changes in brain morphology and changes of course of the trigeminal nerve may also add to the possibility of developing TN, especially of venous etiology., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Isolated sinus dural arteriovenous fistulas (DAVFs) involve a dural sinus with occlusion on both sides of the diseased sinus segment. Because of venous drainage refluxing from the isolated sinus into the cortical veins, all isolated sinus DAVFs are Borden type III or Cognard type Ⅲ/Ⅳ. Venous drainage typically involves temporo-occipital cortical veins or the superior petrosal sinus and tributaries of the petrosal vein. However, drainage veins involving the perimedullary venous system are extremely rare. Here, we present a case of Cognard type V isolated sinus DAVF successfully treated with balloon catheter and Onyx., (Copyright © 2023. Published by Elsevier Inc.)

Background: Transsylvian approaches are a cornerstone of complex cranial operations, with wide applicability across cerebrovascular, skull base, and neuro-oncology operations. Deep lesions, especially those involving the basilar apex, midbrain, or interpeduncular fossa, require wide exposures that may be inhibited by the presence of a large complex of superficial sylvian veins (SSV) draining into the sphenoparietal sinus. This report describes technical and clinical aspects of the sphenoparietal sinus transposition (SPST) technique., Methods: Technical case report of the SPST technique, including a step-by-step neuroanatomic description, overview of common indications, clinical pearls and pitfalls, and illustrative case examples., Results: Once the benefits of proceeding with SPST have been established, the maneuver is initiated with 2 stepwise dural incisions: an incision from lateral to medial along the lateral margin of the lesser sphenoid wing, followed by an orthogonal cut across the temporal pole down the middle fossa floor. The pretemporal dura is peeled off the lateral wall of the cavernous sinus, allowing mobilization of the SSV complex and temporal pole posteriorly without disrupting or straining the connection point at the sphenoparietal sinus. Illustrative case examples include a clip reconstruction of a basilar apex aneurysm for which earlier endovascular treatment had failed and microsurgical resection of a peduncular cavernous malformation., Conclusions: SPST is a simple but versatile technique with important applications in complex cranial surgery. By mobilizing the SSV complex together with its dural attachment, the transsylvian corridor can be markedly widened, allowing access to the basilar apex region and ventral midbrain., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Anatomical studies of the tentorial sinuses (TS) are scant, and to our knowledge, histological studies of this structure have not been reported. Therefore, we aim to better elucidate this anatomy., Methods: In 15 fresh frozen, latex injected, adult cadaveric specimens, the TS were evaluated with microsurgical dissection and histology., Results: The superior layer had a mean thickness of 0.22 mm, and the inferior layer had a mean thickness of 0.26 mm. Two types of TS were identified. Type 1 was a small intrinsic plexiform sinus with no obvious connections to the draining veins with gross examination. Type 2 was a larger tentorial sinus with direct connections to the bridging veins from the cerebral and cerebellar hemispheres. In general, type 1 sinuses were located more medially than type 2 sinuses. The inferior tentorial bridging veins drained directly into the TS along with connections to the straight and transverse sinuses. In 53.3% of specimens, superficial and deep sinuses were seen, with superior and inferior groups draining the cerebrum and cerebellum, respectively., Conclusions: We identified novel findings for the TS which can be considered surgically and when diagnosing pathology involves these venous sinuses., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: A dural arteriovenous fistula involving the superior petrosal vein (SPV DAVF) is an extremely rare condition. Therefore, its clinical presentation, imaging characteristics, treatment methods, and risk factors remain unclear. In this study, we discuss and analyze the aforementioned features of an SPV DAVF., Methods: We retrospectively reviewed 30 patients with SPV DAVFs, with a 1-year follow-up rate of 96.67% (29 of 30). The neurological function of the patients was assessed using the modified Aminoff-Logue scale and the modified Rankin Scale score. The risk factors before and after treatment were established using univariate and multivariate logistic regression analyses. Additionally, treatments involving 3 distinct SPV DAVF drainage patterns were presented., Results: Of the 30 patients, 24 were men (80.0%). Besides, the angiography images were reexamined 12 months after surgery. Univariate analyses indicated that the extent of edema (odds ratio 1.889, 95% confidence interval 1.132-3.154) and the number of draining veins (≤2) (odds ratio 10.833, 95% confidence interval 1.961-59.834) were risk factors for pretreatment modified Rankin Scale score ≥3. However, multivariate analyses revealed no statistically significant differences (P = 0.051, P = 0.055). Following the multivariate analyses, steroid pulse (odds ratio 12.153 95% confidence interval 1.080-136.772) was found to be the only significant risk factor for post-treatment difference between pretreatment and 1-year follow-up modified Rankin Scale score ≥2., Conclusions: A DAVF with SPV drainage is an uncommon type of intracranial vascular malformation. Most lesions involve the brain stem or high cervical spinal cord, thereby posing a higher risk of disability or death. Moreover, neuronal damage from persistent venous hypertension is permanent. Therefore, precise diagnosis and timely treatment are key to a good patient prognosis., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objectives: The risks and benefits of coagulating intradural venous elements during a retrosigmoid approach for trigeminal neurovascular decompression has not been accurately established. The objectives of this study were to identify the veins that drain into the superior petrosal sinus, classify them in relation to the suprameatal tubercle, and determine the implication of their coagulation., Methods: A retrospective study of 3-dimensional surgical videos of retrosigmoid approaches for trigeminal neurovascular decompression from the Laboratory of Neurosurgical Innovations of Tucumán (LINT) digital archive was carried out. The veins encountered were classified into 3 groups: retromeatal, meatal and premeatal. The neurosurgical postoperative complication scale proposed by Landriel et al. was utilized to assess complications from venous coagulation. A grade 0 was added for patients without complications. The STATA 14 program was utilized for statistical analysis., Results: The pontocerebellar-petrosal veins of 28 patients who underwent trigeminal decompressive surgery were analyzed. In 7 cases these were found in the retromeatal region; 100% were sacrificed. Eleven cases revealed veins within the meatal region; 90.91% were coagulated. Veins in the premeatal region were found in 14 cases; 57.14% were sacrificed. In the postoperative follow-up, 27 patients were grade 0 and 1 patient developed postoperative meningitis (grade Ib complication). No patient suffered vascular complications., Conclusions: The venous elements identified in trigeminal neurovascular decompressive surgery are variable. We propose classifying them into retromeatal, meatal, and premeatal groups. Retromeatal and meatal veins can be safely sacrificed for appropriate visualization of the neurovascular conflict. The premeatal venous elements should be coagulated only in justified cases., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Surgical planning for treating brain arteriovenous malformations (bAVMs) is challenging because it entails visualizing 3-dimensional (3D) relationships between the nidus, its feeding and en passage arteries, and draining veins. Surgical experience in developing the capacity to mentally visualize pathological bAVM angioarchitecture could be complemented by this software, and thus potentially lower the steep learning curve for understanding complex bAVM angioarchitecture. We evaluated the clinical application of freely available online 3D reconstruction software in facilitating visualization of AVM angioarchitecture for presurgical planning., Methods: Preoperative Digital Imaging and Communications in Medicine magnetic resonance imaging/magnetic resonance angiography images of 56 superficial bAVMs from 2013 to 2018 were processed using open-source software Horos. 3D rendered images were compared with the surgical view to evaluate software accuracy and determine its value as a preoperative tool. 3D reconstructed images were compared with intraoperative recordings., Results: A useful image identifying both the main feeding artery and draining vein was achieved in 35 of 56 cases (62.5%). Reconstructions of small AVMs (nidus ≤2 cm) and those located within the temporal or cerebellar cortex were less useful due to soft tissue artifacts. Frontal and parietal lobe lesions had significantly higher rates of identifying feeding arteries and draining veins (P < 0.05)., Conclusion: Presurgical planning for resection of superficial bAVMs using Horos software allows for a comprehensive 3D analysis of the bAVM angioarchitecture. This technique is most useful for frontal and parietal lobe lesions, and aids the surgeon in formulating an optimal surgical strategy. The 3D reconstruction of the brain surface offers a surgical map not influenced by brain shift., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: High-positioned and/or superoposteriorly directed anterior communicating artery aneurysms can be treated by direct clipping using the pterional (fronto-temporo-sphenoidal) approach. This procedure, however, requires stronger retraction of the frontal lobe. Hence, preservation of the prominent frontal bridging veins (FBVs) draining into the sphenoparietal sinus (SPS) remains a significant challenge in preventing postoperative venous congestion., Methods: We developed a technique to release the tension on the FBVs by pulling them together with the SPS epidurally. In 2 patients, who had presented with high-positioned and/or superoposteriorly directed anterior communicating artery aneurysms, we peeled off the arachnoid surrounding the FBVs and detached it from the brain surface. We further released the veins by moving them posteriorly, together with the SPS epidurally., Results: Using this technique, we established a wide corridor through a more lateral transsylvian trajectory with effective posterior retraction of the frontal lobe and were successful in clipping and obliterating the aneurysms., Conclusions: Open clipping of unruptured intracranial aneurysms requires accuracy to preserve higher brain function. Our technique was successful in both patients, and preserving the FBVs could be useful in the treatment of such aneurysms., (Copyright © 2021 Elsevier Inc. All rights reserved.)

This review is the first comprehensive anatomic report of all venous eponyms used in vascular neurosurgery and provides the historical context of their authors as well as the surgical relevance of every structure. A PubMed literature review identified 13 individuals for whom 18 eponymous venous structures of the brain were named. These structures are the Batson plexus, veins of Breschet, Breschet sinus, vein of Dandy, vein of Galen, prosencephalic vein of Markowski, torcular Herophili, vein of Labbé, venous plexus of Rektorzik, vein of Rolando, basal vein of Rosenthal, sylvian veins, lateral lakes of Trolard, vein of Trolard, hypoglossal plexus of Trolard, petro-occipital vein of Trolard, venous circle of Trolard, and the vein of Vesalius. Eponyms provide a valuable shorthand that encompasses anatomic nuances, variabilities, and surgical relevance. In addition, they elucidate the historical context in which these structures were described and are an academic honor to our predecessors., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: The anatomy of the veins in the pineal region is one of the most complex areas in the brain because all major deep cerebral veins converge there: the internal cerebral veins (ICVs), the great cerebral vein of Galen (GV), the basal veins (BVs), and the internal occipital veins (IOVs). The aim of this study was to comprehensively describe the anatomy of the veins in the pineal region using computed tomography angiography., Methods: Head computed tomography angiography scans of 250 adult Polish patients were evaluated. We assessed the location of the junction of 2 ICVs and the presence of a narrowing of the GV and arachnoid granulation at the GV-straight sinus junction. We evaluated the presence, appearance, and termination of the BV, and the presence and termination of the IOV., Results: The study showed that 2 ICVs usually converged posterior to the splenium of the corpus callosum (62.4%). Narrowing of the BV was observed in 51.2% of patients, and the arachnoid granulation was found in 25.2%. The 3 segments of the BV were well visualized in 66% of the studied hemispheres. The BV flowed into the GV in 34.8% of the hemispheres. The IOV was present in 90.2% of the hemispheres and terminated medially in 84.5%., Conclusions: Because an injury to major deep cerebral veins may result in severe postoperative neurologic deficits, it is essential for neurosurgeons to be familiar with both normal and variant patterns of veins in the pineal region., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: Microvascular decompression (MVD) is a commonly-used treatment option for medically-refractory trigeminal neuralgia (TN) with arterial neurovascular compression. Pain control and recurrence rates after MVD in patients with purely venous compression are not well understood. In this systematic review and meta-analysis, we studied outcomes after MVD in patients with purely venous compression and reviewed the operative management in these patients., Methods: We performed a systematic review and meta-analysis following the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. We searched PubMed, Google Scholar, and Scopus databases for studies reporting surgical outcomes after MVD for purely venous compression. Pain control and recurrence rates were extracted and summarized. Studies that reported outcomes after mobilization/decompression compared with coagulation/transection of compressive veins were reviewed., Results: We identified and included 24 studies with a total of 330 patients in this study. 75.6 % of patients achieved a Barrow Neurological Institute (BNI) I pain score with a mean follow-up of 38.0 months. Pain recurred in 23.1 % of patients at a mean follow-up of 51.4 months. There was no significant difference in pain control outcomes between patients with mobilization/decompression and patients with coagulation/transection of compressive veins., Conclusion: After MVD in patients with venous compression alone, pain control rates were similar to those reported for arterial compression, though recurrence rates were higher. There was no difference between vein coagulation/transection compared to mobilization/decompression. Further studies are needed to determine the optimal treatment paradigm for patients with purely venous compression., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Superior petrosal sinus (SPS) dural arteriovenous fistulas (DAVFs) are a common subtype of tentorial DAVFs that often require microsurgical treatment. We have noted a rare condition involving the presence of a coexisting normal superior petrosal vein (SPV) during surgery for SPS DAVFs; this condition has not been reported in the literature. Identification and preservation of coexisting normal veins are crucial to prevent venous complications., Methods: We reviewed data of 12 patients with SPS DAVFs who underwent microsurgical treatment. Intraoperative indocyanine green video angiography was used to confirm the location of the fistula and identify the normal SPV. Postoperative radiologic examination was performed, and the clinical outcome was evaluated with the modified Rankin Scale., Results: A coexisting normal functional SPV was found in 6 cases. Analysis of the tributaries of the SPV showed the vein of the cerebellopontine fissure was the most frequent arterialized drainage vein (66.7%), while the pontotrigeminal vein was the most frequent normal drainage vein (45.5%). The DAVFs were easily identified and disrupted using intraoperative indocyanine green video angiography. The normal SPV was also successfully preserved. All 6 patients experienced good clinical and radiologic outcomes., Conclusions: An SPS DAVF can coexist with a normal functional SPV, which should be preserved. Use of indocyanine green video angiography is an efficient way to identify the normal SPV., (Copyright © 2020. Published by Elsevier Inc.)

Background: Several microvascular decompression technical variations for the treatment of medically refractory trigeminal neuralgia have been proposed that can be categorized generally as interposition and transposition techniques. These latter approaches, so-called slinging techniques, have been increasing in popularity, because they can possibly reduce the long-term recurrence rates by preventing the formation of fibrosis and granulomas at the decompression site. We have reported a technique for transposition of the superior cerebellar artery for microvascular decompression in trigeminal neuralgia using the superior petrosal vein as an in situ sling to anchor and reroute the artery away from the nerve., Methods: We have presented a technical report with illustrative intraoperative images and video from 2 cases of trigeminal neuralgia in which the superior petrosal vein was used as a simple and straightforward in situ sling for transposition of the superior cerebellar artery., Results: The technique was applied successfully in 2 patients with complete and immediate remission of trigeminal neuralgia, without surgical morbidity., Conclusion: The most frequent neurovascular conflict in trigeminal neuralgia involves the superior cerebellar artery, and the strategic location of the superior petrosal vein relative to this neurovascular complex allows for its use as a natural in situ sling that reroutes the artery and prevents its recoil against the nerve. This technique can be added to the increasing armamentarium of transposition techniques for microvascular decompression, with the advantage of simplicity and no requirement for a complex prosthesis to secure the transposition., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: The incidence of traumatic arteriovenous fistula (TAVF) between the middle meningeal artery (MMA) and the petrosal vein (PV) is rare. Although TAVF has been reported involving the MMA several sinus and veins, this is the first incidence of a fistula involving the extracranial MMA and PV., Case Description: We present a 47-year-old male with sudden onset of weakness of his right limb and speech difficulty a few hours before admission to our facility. He had a 6-month history of mild traumatic head injury. Initial computed tomography revealed midbrain hemorrhage while digital subtraction angiography revealed a TAVF of the left MMA. Enhanced magnetic resonance imaging, however, revealed communication between the MMA and PV. We treated the patient with coil embolization via the transarterial route., Conclusions: This is the first incidence of a fistula connecting the extracranial MMA and PV. We managed the patient with only coil embolization without any further neurologic deficits., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Pial arteriovenous fistulas are abnormal vascular connections between arteries and the cranial venous system on the surface of the brain in the pia mater. In contrast to vein of Galen aneurysmal malformations, they lack a true vascular nidus and may only indirectly involve the vein of Galen., Case Description: An 18-month-old boy was referred to us with a history of seizures, drowsiness, bulging cephalic veins, and cranial nerves palsy identified as vein of Galen aneurysmal malformation according to initial magnetic resonance imaging. Digital subtraction angiography showed a vertebrobasilar junction pial high-flow fistula between the basilar artery and anterior pontomesencephalic vein, causing retrograde flow, dilation, and tortuosity of the lateral and posterior mesencephalic vein as well as the vein of Galen. Endovascular treatment, including coil embolization of fistula site, was done successfully without complication resulting in recovery from previous symptoms and signs., Conclusions: If cerebral venous dilations are encountered, one must keep in mind that the location of the fistula may not be in close proximity to the dilated veins, especially when there is a suspicion for vein of Galen aneurysmal malformation. Other pathologies, such as pial arteriovenous fistula, in a region away from the site of the vein of Galen must be considered., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Embolization of arteriovenous malformations is characteristically used as part of a multimodal treatment approach, pre-operatively to facilitate microsurgical resection or as a preradiosurgical adjunct. The concept of AVM cure via embolization alone has gained popularity in recent years. Embolization of AVMs has been most commonly performed transarterially, with the transvenous route traditionally eschewed given concern over precipitating premature venous occlusion and consequent hemorrhage. However, the transvenous approach in treating AVMs offers several distinct advantages compared to the transarterial route and can be used in instances when the latter is not feasible, with several series having proven its efficacy and safety. Conceptually, AVM embolization performed via the transvenous route achieves complete obliteration by directly and facilely targeting the nidus. Nidal embolisate penetration is facilitated by control of arterial inflow via systemic or local hypotension. Innovation in endovascular strategies has led to significantly improved obliteration rates. The experience with transvenous AVM embolization is reviewed and discussed., (Copyright © 2018. Published by Elsevier B.V.)

An understanding of the anatomy and function of the skull base venous channels is fundamentally important for safe performance of endoscopic surgery for skull base lesions. This review focuses on 4 skull base venous channels-namely, the intercavernous sinuses, basilar plexus, osseous veins, and inferior petroclival vein-because these have been less recognized by neurosurgeons than other major venous channels such as the inferior petrosal sinus. We reviewed the literature concerning these 4 venous channels and discussed their anatomy and function. The literature review was mainly based on an electronic search in PubMed using the following terms: "intercavernous sinus," "basilar plexus," "emissary veins," "diploic vein," "basilar plexus," "intraosseous vein," "inferior petroclival/petro-occipital vein," and "transclival." A total of 50 articles were included in this review. Detailed anatomic features of the 4 structures have been elucidated in the literature. All of these venous channels run along the skull base and have multiple connections with surrounding venous structures. Because of their location, they occasionally obstruct the surgical view and are sometimes implicated in intraoperative hemorrhage, air embolism during endoscopic skull base surgery, and postoperative hematoma. They usually function as a venous reservoir of cranial venous drainage; however, they are less often directly involved in normal brain perfusion. Knowledge about the functional and morphologic anatomy of the skull base venous channels is important for neurosurgeons to avoid unexpected complications during endoscopic skull base surgery., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Cerebral venous anomaly (CVA) is a rare congenital malformation. Caput medusa and stripe signs were the most common imaging findings in CVA patients. Here, we present the case of a thrombosed CVA with a double annular enhancement in a 62-year-old male with a 2-month history of worsening headaches., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Complications arising from cerebral venous occlusion/sacrifice during neurosurgical procedures have received comparatively less attention in the neurosurgical literature. Consequently, cerebral venous complications are not given due recognition, even though most practicing neurosurgeons would agree that they are not uncommon. We present a review of complications arising from venous sacrifice/occlusion during neurosurgery and discuss strategies described in the literature to prevent such occurrences., Methods: We conducted a systematic review of the literature to provide a synopsis of the current evidence regarding cerebral venous injury after a neurosurgical procedure. The objectives of this review were to assess the incidence of venous injuries after a neurosurgical procedure with their clinical outcome and to evaluate current strategies and technical advances for their prevention. Complications related to dural venous sinuses were not considered in this review., Results: Twenty-six relevant articles were identified and reviewed. Complications from cerebral venous occlusion/sacrifice are being increasingly recognized, and venous preservation strategies are being promoted in the neurosurgical literature. Based on our review of literature, the incidence of venous injury can range from 2.6% to 30%. We discuss the pathophysiology after venous injury and factors affecting outcome after cerebral venous injury. An overview of surgical techniques described to prevent or manage venous injury during neurosurgical procedures is presented., Conclusions: The unpredictable response of the brain to venous injury causes catastrophic complications in a few patients. To avoid these complications, meticulous venous preservation should be a goal in all neurosurgical procedures. Increased recognition of cerebral venous complications over the last 2 decades has resulted in the increasing recognition among neurosurgeons that venous preservation is an essential tenet of neurosurgery., (Copyright © 2018. Published by Elsevier Inc.)

Background: Microvascular decompression of the trigeminal nerve is the most effective treatment for trigeminal neuralgia. However, when encountering classical trigeminal neuralgia caused by venous compression, the procedure becomes much more difficult, and failure or recurrence because of incomplete decompression may become frequent. This study aimed to investigate the anatomic variation of the culprit veins and discuss the surgical strategy for different types., Methods: We performed a retrospective analysis of 64 consecutive cases in whom veins were considered as responsible vessels alone or combined with other adjacent arteries. The study classified culprit veins according to operative anatomy and designed personalized approaches and decompression management according to different forms of compressive veins. Curative effects were assessed by the Barrow Neurological Institute (BNI) pain intensity score and BNI facial numbness score., Results: The most commonly encountered veins were the superior petrosal venous complex (SPVC), which was artificially divided into 4 types according to both venous tributary distribution and empty point site. We synthetically considered these factors and selected an approach to expose the trigeminal root entry zone, including the suprafloccular transhorizontal fissure approach and infratentorial supracerebellar approach. The methods of decompression consist of interposing and transposing by using Teflon, and sometimes with the aid of medical adhesive. Nerve combing (NC) of the trigeminal root was conducted in situations of extremely difficult neurovascular compression, instead of sacrificing veins. Pain completely disappeared in 51 patients, and the excellent outcome rate was 79.7%. There were 13 patients with pain relief treated with reoperation. Postoperative complications included 10 cases of facial numbness, 1 case of intracranial infection, and 1 case of high-frequency hearing loss., Conclusions: The accuracy recognition of anatomic variation of the SPVC is crucial for the management of classical trigeminal neuralgia caused by venous compression. Selecting an appropriate approach and using reasonable decompression methods can bring complete postoperative pain relief for most cases. NC can be an alternative choice for extremely difficult cases, but it could lead to facial numbness more frequently., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: To investigate potential effect of sacrifice of the superior petrosal vein (SPV) on postoperative complications after microvascular decompression (MVD)., Methods: Retrospective review of 98 consecutive patients undergoing MVD of cranial nerve V was performed. Frequency of division of the SPV during surgery was recorded, and postoperative complications and imaging were recorded and analyzed. In patients with complications, the specific anatomic variation of the superior petrosal venous complex was noted., Results: Of 98 patients undergoing MVD, 83 (84.7%) had sacrifice of the SPV at the time of surgery, 12 (12.2%) had the SPV preserved, and 3 (3.1%) were revision operations. Four patients (4.8%) had complications deemed to be attributable to venous insufficiency or congestion. These included sigmoid sinus thrombosis with coincident cerebellar hemorrhage, midbrain and pontine infarction, hemiparesis with midbrain and pontine edema, and facial paresis with ischemia in the middle cerebellar peduncle. None of the patients with preserved SPV were symptomatic or had imaging changes consistent with venous congestion., Conclusions: Sacrifice of the SPV is often performed during MVD. This is associated with a complication rate that is significant in frequency and severity compared with preserving the vein. SPV sacrifice should be limited to cases where it is deemed absolutely necessary for successful cranial nerve decompression., (Copyright © 2017. Published by Elsevier Inc.)

Background: Patients with cavernous sinus dural arteriovenous fistulas (CS dAVFs) with cortical venous varix are indicated for aggressive treatment because of the associated risk for intracranial hemorrhage., Case Description: We present a case of surgical transvenous embolization in an 84-year-old woman with CS dAVF who presented with massive intracerebral hematoma. Cerebral angiograms revealed the dural AVF drained only into the superficial middle cerebral vein. Because an emergent mass reduction and prevention of rebleeding were necessary, single-session hematoma removal and transcranial embolization of a CS dAVF were performed in the neurosurgical operating room, using a mobile C-arm fluoroscopy. After the right frontotemporal craniotomy, intracerebral hematoma was removed and coil packing of the affected cavernous sinus was successfully performed via the dilated superficial middle cerebral vein., Conclusion: The transcortical vein approach enables occlusion of CS dAVF with isolated cortical venous drainage and may be a valuable alternative approach for some cases needed emergency craniotomy., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Operation of cortical veins is the keystone of parasagittal meningioma (PSM) resection. Little is known about pathologic changes of the veins and proper treatment. We built 3-dimensional (3D) image fusion models by neuronavigation to analyze the features of peritumoral cortical veins for PSMs and explore intraoperative treatment options., Methods: We performed a prospective study of 42 consecutive surgically treated PSM patients who underwent preoperative evaluation of peritumoral cortical veins using a 3D venous-tumor fusion model established by a neuronavigation system. We categorized cortical veins into 3 types: single-end anastomosis (type a), tumor-to-end anastomosis (type b), and end-to-end anastomosis (type c). We present surgical strategies to operate these veins., Results: Preoperative evaluation demonstrated 39 patients with peritumoral cortical veins. The 3D models show 100% of the veins (95 in total), which were confirmed intraoperation. The postoperative complication rates after vein injury were 60% (type a), 16.7% (type c), and 0% (type b). Ten patients (23.8%) had residual tumor because of venous protection (equal to Simpson grade III). After correlation analysis, type b and c cortical veins were positively correlated with tumor volume., Conclusions: The anastomoses of cortical veins may provide compensation for venous transaction. There may be a time-evolution relationship between different cortical veins (type a to c to b). Treatment of cortical veins should follow the following principles: single-end veins must be protected, tumor-to-end veins should be transacted directly, and end-to-end veins could be cut selectivity based on the degree of occlusion of the superior sagittal sinus. Detailed preoperative assessment of peritumoral cortical veins is critical for proper treatment., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Preservation of the superficial Sylvian veins (SSVs) is essential to prevent neurologic deficits during Sylvian dissection. We describe an appropriate surgical approach for unruptured middle cerebral artery (MCA) aneurysms to preserve these veins by using indocyanine green videoangiography (ICG-VA)., Methods: Between August 2014 and August 2015, we performed microsurgical clipping for 37 unruptured MCA aneurysms in 36 patients. We classified all of the cases into 3 types according to the location between the Sylvian fissure and the SSV. We defined 3 surgical approaches (frontosylvian, intersylvian, and temporo-sylvian) based on the SSV and investigated the proper surgical approach according to the type of case., Results: In our study, most SSVs were located above the Sylvian fissure (fissure type, 64.9%). The SSV was located on the temporal lobe in 10 cases (temporal type) and on the frontal lobe in 3 cases (frontal type). The frontosylvian approach (splitting between the SSV and frontal lobe) was performed in all of the patients with temporal type; the temporo-sylvian approach (splitting between the SSV and temporal lobe) was performed in all of the patients with frontal type and single SSV of fissure type. The intersylvian approach (splitting between the frontal and temporal SSV, or among multiple SSVs) was successfully performed in the patients with double or multiple SSVs of fissure type. No venous complications occurred that were related to the surgical approach., Conclusions: Correct dissection strategy using intraoperative ICG-VA is greatly useful to define the optimal surgical approach without vein injury., (Copyright © 2016. Published by Elsevier Inc.)

Background: Cavernous sinus (CS) dural arteriovenous fistula (DAVF) rarely causes intracranial hemorrhage. The authors describe a case of CS DAVF presenting with intracranial hemorrhage, focusing on the findings in digital subtraction angiography (DSA) performed before and after the onset., Case Description: An 80-year-old woman, diagnosed as Borden type 3 CS DAVF on DSA 2 years before, presented with subarachnoid hemorrhage and right temporal subcortical hemorrhage. DSA findings after the onset showed that the right superficial middle cerebral vein, the sole drainage of the DAVF, had various changes including stenosis on the proximal portion, venous pouch formation, and occlusion of the distal portion compared with those 2 years before the onset. The occlusion was observed near the point where drainage of DAVF joined normal brain venous drainage, suggesting that the competition between the drainages caused impaired venous drainage, stagnation, and subsequent thrombotic occlusion. The CS DAVF was treated with evacuation of the intracerebral hematoma and surgical interruption of the right superficial middle cerebral vein at the dural origin from the CS., Conclusions: This report showed the development of thrombotic occlusion of a distal draining cortical vein as one of risk factors for CS DAVFs to cause intracranial hemorrhage on repeated DSAs., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: To elucidate venous drainage patterns to avoid damage to the venous drainage route in the middle cranial fossa and superior petrosal sinus when employing the transpetrosal approach., Methods: Venous drainage patterns were assessed using three-dimensional computed tomography venography in 22 hemispheres of petroclival meningioma (PCM) cases from patients who underwent primary surgery and 40 hemispheres of control cases. Intracranial venous drainage patterns were compared between control cases and PCM cases., Results: The proportion of hemispheres with complete and medial superior petrosal sinus drainage patterns was lower in PCM cases. With regard to the superficial middle cerebral vein drainage pattern, the proportion of hemispheres with the cavernous sinus capture type was lower and the proportion with the emissary type was higher in PCM cases. The proportion of hemispheres with multiple greater anastomoses of the superficial middle cerebral vein was higher in PCM cases without the emissary-type and cavernous sinus capture-type patterns. When the venous drainage route of the cavernous sinus capture type and/or emissary type was disturbed, in particular, greater anastomosis via the vein of Labbè and the vein of Trolard was needed to control venous drainage flow., Conclusions: In cases of venous drainage impairment secondary to PCM progression, the drainage route changed to the pterygoid plexus route through the emissary foramen and/or superior sagittal sinus and to the transverse sinus route through the greater anastomosis of the superficial middle cerebral vein. In the anterior transpetrosal approach, peeling off the dura propria of the trigeminal nerve of the foramen rotundum for petrous apex exposure may be associated with the potential risk of pterygoid plexus drainage route impairment., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: We used microscopy to conduct qualitative and quantitative analysis of 4 surgical approaches commonly used in the surgery of the ambient cistern: infratentorial supracerebellar (SC), occipital interhemispheric, subtemporal (ST), and transchoroidal (TC). In addition, we performed a parahippocampal gyrus resection in the ST context., Methods: Each approach was performed in 3 cadaveric heads (6 sides). After the microscopic anatomic dissection, the parahippocampal gyrus was resected through an ST approach. The qualitative analysis was based on anatomic observation and the quantitative analysis was based on the linear exposure of vascular structures and the area of exposure of the ambient cistern region., Results: The ST approach provided good exposure of the inferior portion of the cistern and of the proximal segments of the posterior cerebral artery. After the resection of the parahippocampal gyrus, the area of exposure improved in all components, especially the superior area. A TC approach provided the best exposure of the superior area compared with the other approaches. The posterolateral approaches (SC/occipital interhemispheric) to the ambient cistern region provided similar exposure of anatomic structures. There was a significant difference (P < 0.05) in linear exposure of the posterior cerebral artery when comparing the ST/TC and ST/SC approaches., Conclusions: This study has demonstrated that surgical approaches expose dissimilarly the different regions of the ambient cistern and an approach should be selected based on the specific need of anatomic exposure., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background and Significance: The vessels of choice for cerebrovascular high-flow direct bypass procedures are the radial artery and the saphenous vein. Radial artery grafts have become favored over saphenous vein grafts because of higher patency rates and better size matching to appropriate recipient vessels. Radial grafts are prone to spasm however, and this may be seen in 4-10% of cases and can be associated with ischemic sequelae. The standard technique for radial artery harvest calls for complete separation of the artery from its adventitial attachments and associated venous network. There is reason to believe that this could contribute to spasm risk and possibly even thrombosis. Radial graft outcomes appear to be improved when the vena comitantes is preserved in cardiac and peripheral applications. We report the novel use of a harvested radial artery graft with preservation of its venae comitantes for extracranial to intracranial bypass., Clinical Presentation: The patient is a 59-year-old male who had a blunt head trauma with associated loss of consciousness and who was led to the incidental discovery of a large fusiform middle cerebral artery (MCA) aneurysm., Conclusion: Preservation of the vena comitantes when harvesting a radial arterial graft for bypass, along with dual (arterial and venous) anastomoses, and concomitant use of intra-operative vaso-dilatory maneuvers to prevent spasm, may improve overall graft patency and patient outcome., (Copyright © 2016. Published by Elsevier B.V.)

Objective: The Sylvian fissure has been dissected through the frontal side of the superficial Sylvian veins with sacrifice of the tributaries of the frontal superficial Sylvian vein, which may lead to venous infarction. In addition, disturbed venous drainage makes the brain susceptible to brain retraction. Therefore, preservation of the vein is essential in modern neurosurgery to decrease morbidity., Methods: We describe the technical nuances of Sylvian dissection with an emphasis on preserving the veins., Results: The arachnoid between the frontal and temporal superficial Sylvian veins is divided as to enter the fissure. After the deep part in the Sylvian fissure is reached, the inside of the fissure is dissected along the "microvascular Sylvian fissure," the temporal side of the frontal vessels or the frontal side of the temporal vessels. The Sylvian fissure is dissected in a deep-to-superficial and posterior-to-anterior fashion ("paperknife technique") up to the skull base. The frontal superficial Sylvian vein usually tethers the brain to the dura, restricting the surgical corridor when approaching deep lesions. Peeling off the arachnoid that wraps this vein ("denude technique") allows the vein to stretch., Conclusions: Keeping the proper dissection plane ("microvascular Sylvian fissure") is crucial to preserve the veins. The "paperknife technique" makes the division of the frontal and temporal lobe easier. The "denude technique" provides a wider space between the frontal lobe and the skull base. These techniques make it possible to obtain a sufficiently wide surgical corridor to the basal cistern without sacrificing the veins and their tributaries., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objectives: To assess the clinical outcome, complications, and angiographic outcomes after surgical disconnection of intracranial dural arteriovenous fistulas (DAVFs)., Methods: Analysis of prospectively collected data, including clinical presentation, preoperative angiographic findings, postoperative complications, clinical, and angiographic outcomes., Results: Between January 2002 and January 2012, 25 patients underwent surgery for DAVFs. The anatomical locations included tentorial (8), ethmoidal (8), foramen magnum (5), middle fossa (2), torcular (1), and parafalcine (1). All had cortical venous reflux (CVR) and all were treated with craniotomy and disconnection of CVR. Two patients required repeat surgery for residual CVR. One patient had a postoperative seizure. There were no other complications. All patients had complete disconnection of CVR confirmed by digital subtraction angiography. None of the patients have had hemorrhage or recurrence of CVR on follow-up., Conclusions: Surgical disconnection of CVR for high-grade intracranial DAVFs is highly effective and can be performed with very low complication rates. Where embolization cannot be performed safely, surgical disconnection (rather than stereotactic radiosurgery) is the treatment of choice for high grade DAVFs., (Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.)

When resecting gliomas, extra-axial tumors, or their overlying cortex, cortical veins may become suspended over the resection cavity and ultimately prolapse and kink into the cavity, promoting venous thrombosis. To prevent this, we describe a technique to secure a Gelfoam scaffold beneath the cortical vein at the edge of the resection cavity to prevent kinking and possible thrombosis from taking place after tumor removal. Depending on the diameter of the resection cavity, this can be done at 1 or both edges of the resection cavity to prevent prolapse of the vein into the cavity. In our experience with this technique, during the past 10 years, there have been no cases of venous thrombosis after tumor removal on postoperative imaging or clinical examination., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objective: Surface-rendered three-dimensional (3D) 1.5-T magnetic resonance (MR) imaging is useful for presurgical simulation of microvascular decompression. This study compared the sensitivity and specificity of 1.5- and 3.0-T surface-rendered 3D MR imaging for preoperative identification of the compression vessels of trigeminal neuralgia., Methods: One hundred consecutive patients underwent microvascular decompression for trigeminal neuralgia. Forty and 60 patients were evaluated by 1.5- and 3.0-T MR imaging, respectively. Three-dimensional MR images were constructed on the basis of MR imaging, angiography, and venography data and evaluated to determine the compression vessel before surgery. MR imaging findings were compared with the microsurgical findings to compare the sensitivity and specificity of 1.5- and 3.0-T MR imaging., Results: The agreement between MR imaging and surgical findings depended on the compression vessels. For superior cerebellar artery, 1.5- and 3.0-T MR imaging had 84.4% and 82.7% sensitivity and 100% and 100% specificity, respectively. For anterior inferior cerebellar artery, 1.5- and 3.0-T MR imaging had 33.3% and 50% sensitivity and 92.9% and 95% specificity, respectively. For the petrosal vein, 1.5- and 3.0-T MR imaging had 75% and 64.3% sensitivity and 79.2% and 78.1% specificity, respectively. Complete pain relief was obtained in 36 of 40 and 55 of 60 patients undergoing 1.5- and 3.0-T MR imaging, respectively., Conclusions: The present study showed that both 1.5- and 3.0-T MR imaging provided high sensitivity and specificity for preoperative assessment of the compression vessels of trigeminal neuralgia. Preoperative 3D imaging provided very high quality presurgical simulation, resulting in excellent clinical outcomes., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: To categorize clinoidal meningiomas according to their venous drainage patterns, and use each category as a guideline to establish an appropriate surgical strategy., Methods: We performed a retrospective analysis of 22 consecutive surgically treated patients with clinoidal meningioma who underwent preoperative digital subtraction angiography to examine the characteristics of the venous drainage system. These patients were categorized into: 1) cortical type in which the sylvian vein did not drain medially but drained to cortical veins, 2) sphenobasal type in which the sylvian vein drained into the pterygoid plexus, or 3) cavernous type in which the sylvian vein drained into the cavernous sinus directly through the sphenoparietal sinus. We tailored the surgical strategy to preserve these draining veins., Results: Preoperative angiographic evaluation demonstrated 14 patients (63.6%) with cortical type, 6 patients (27.3%) with sphenobasal type, and 2 patients (9.1%) with the cavernous type. In most cases, no restriction from the venous structure was observed because the sylvian vein belonged to the cortical type. However, in the case of the sphenobasal or sphenoparietal type, the surgical strategy seemed to be tailored to preserve the venous drainage system., Conclusions: The surgical risk from venous complication in the treatment of clinoidal meningiomas appears to be low; however, there are likely to be patients that require a tailored surgical approach to avoid venous complications. Detailed preoperative assessment of anatomic structure and consideration of the optimal surgical strategy are critical to improve treatment outcomes., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: The coexistence of cavernous malformations (CMs) and developmental venous anomalies (DVAs) in the cerebellopontine angle (CPA) is exceedingly rare. To the authors' knowledge, only one case of CPA CM with concurrence of a neighboring DVA has been reported to date., Case Description: The authors presented such vascular malformations in a 36-year-old man with progressive CPA syndrome during the course of six weeks. Preoperative neuroimaging suggested the diagnosis of an extra-axial hemorrhagic lesion in the CPA cistern with a cerebellar DVA in the close vicinity. The lesion was totally removed with the DVA untouched and was confirmed to be extra-axial in intimate contact with only the VII-VIII complex and the draining veins of DVA. Pathology revealed a CM. The patient underwent partial improvement in neurological function postoperatively. The radiographic follow-up at one year revealed no recurrence., Conclusions: CMs should be considered in the differential diagnosis of any extra-axial hemorrhagic mass, especially with a DVA in the proximity. The coexistence of CM and DVA in CPA, although maybe just a coincidence, suggests the possibility of a new subtype of extra-axial CPA CM secondary to a preexisting DVA. A long-term follow-up is justified in discovering the potential mechanism and biology of such uncommon vascular malformations., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Objective: Drawbacks of the far-lateral approach to the lower clivus and pontomedullary region include the morbidity of a large incision extending into the cervical musculature and tedious exposure of the vertebral artery (VA), particularly when performing the transcondylar and transtubercular extensions. The authors describe a minimally invasive alternative to the far-lateral approach that has the potential to minimize operative morbidity and decrease the need for VA manipulation., Methods: The minimally invasive supracondylar transtubercular (MIST) and far-lateral supracondylar transtubercular (FLST) approaches were performed in 10 adult cadaveric specimens (20 sides). The microsurgical anatomy of each step and the surgical views were analyzed and compared. In addition, the endoscopic view through the MIST was examined in five fresh cadaveric specimens (10 sides)., Results: The MIST approach provided exposure of the inferior-middle clivus, the anterolateral brainstem, and the premedullary cisterns, including the PICA-VA and vertebrobasilar junctions. The endoscope provided a clear view of cranial nerves III through XII, as well as the vertebrobasilar system. The FLST approach increased visualization of the anterolateral margin of the foramen magnum; otherwise, the surgical view is similar between the MIST and FLST approaches., Conclusions: The MIST approach could be considered as a potential alternative to the FLST approach in the treatment of lesions involving the inferior and middle clivus, and anterolateral lower brainstem; it does not require a C1 laminectomy, significant disruption of the atlanto-occipital joint, nor extensive exposure of the extracranial VA. Moreover, the MIST approach is an ideal companion to endoscope-assisted neurosurgery., (Copyright © 2012 Elsevier Inc. All rights reserved.)