Search

Rationale: Foreign bodies in the vasculature usually cause numerous problems for clinical physicians. Physician experience with diagnosing and treating non-iatrogenic foreign body migration in the venous system is insufficient., Patient Concerns: Here, we reported a 41-year-old male who had a foreign body in his left forearm following a work-related injury., Diagnoses: X-ray films indicated a 3-mm high-density shadow in the superficial soft tissue of the left forearm. During the operation, the foreign body was imaged by a C-arm fluoroscope to provide a more accurate location., Interventions: The foreign body was removed completely following a microsuture of the cephalic vein., Outcomes: The procedure was uneventful, and the patient remained asymptomatic after 6 months of clinical follow-up., Lessons: This case indicated that the foreign body in the superficial tissue needed to be accurately diagnosed and located. X-ray and C-arm fluoroscope imaging should be combined with the patient's medical history to ensure sufficient preoperative preparation.

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 Neural interface technology may enable the development of novel therapies to treat neurological conditions, including motor prostheses for spinal cord injury. Intracranial neural interfaces currently require a craniotomy to achieve implantation and may result in chronic tissue inflammation. Novel approaches are required that achieve less invasive implantation methods while maintaining high spatial resolution. An endovascular stent electrode array avoids direct brain trauma and is able to record electrocorticography in local cortical tissue from within the venous vasculature. The motor area in sheep runs in a parasagittal plane immediately adjacent to the superior sagittal sinus (SSS). The authors aimed to develop a sheep model of cerebral venography that would enable validation of an endovascular neural interface. METHODS Cerebral catheter venography was performed in 39 consecutive sheep. Contrast-enhanced MRI of the brain was performed on 13 animals. Multiple telescoping coaxial catheter systems were assessed to determine the largest wide-bore delivery catheter that could be delivered into the anterior SSS. Measurements of SSS diameter and distance from the motor area were taken. The location of the motor area was determined in relation to lateral and superior projections of digital subtraction venography images and confirmed on MRI. RESULTS The venous pathway from the common jugular vein (7.4 mm) to the anterior SSS (1.2 mm) was technically challenging to selectively catheterize. The SSS coursed immediately adjacent to the motor cortex (< 1 mm) for a length of 40 mm, or the anterior half of the SSS. Attempted access with 5-Fr and 6-Fr delivery catheters was associated with longer procedure times and higher complication rates. A 4-Fr catheter (internal lumen diameter 1.1 mm) was successful in accessing the SSS in 100% of cases with no associated complications. Complications included procedure-related venous dissection in two major areas: the torcular herophili, and the anterior formation of the SSS. The bifurcation of the cruciate sulcal veins with the SSS was a reliable predictor of the commencement of the motor area. CONCLUSIONS The ovine model for cerebral catheter venography has generalizability to the human cerebral venous system in relation to motor cortex location. This novel model may facilitate the development of the novel field of endovascular neural interfaces that may include preclinical investigations for cortical recording applications such as paralysis and epilepsy, as well as other potential applications in neuromodulation.

Indocyanine green (ICG) emits fluorescence in the far-red domain under light excitation. ICG video angiography (ICG-VA) has been established as a useful method to evaluate blood flow in the operative field. We report the usefulness of ICG-VA for Sylvian fissure dissection in patients with subarachnoid hemorrhage (SAH). Subjects comprised 7 patients who underwent ICG-VA before opening the Sylvian fissure during neck clipping for ruptured cerebral aneurysm. We observed contrasted Sylvian veins before opening the Sylvian fissure using surgical microscopes. This procedure was termed "Sylvian ICG". We observed ICG fluorescence quickly in all cases. Sylvian veins that appeared unclear in the standard microscopic operative field covered with subarachnoid hemorrhage were extremely clearly depicted. These Sylvian ICG findings were helpful in identifying entry points and the dissecting course of the Sylvian fissure. At the time of clipping, no residual fluorescence from Sylvian ICG was present, and aneurysm clipping was not impeded. Sylvian ICG for SAH patients is a novel technique to facilitate dissection of the Sylvian fissure. We believe that this technique will contribute to improved safety of clipping surgery for ruptured aneurysms.

Background and Purpose: Although current guidelines advocate pretreatment with intravenous thrombolysis (IVT) in all eligible patients with acute ischemic stroke with large-vessel occlusion before mechanical thrombectomy, there are observational data questioning the efficacy of this approach. One of the main arguments in favor of IVT pretreatment is the potential for tissue-type plasminogen activator-induced successful reperfusion (SR) before the onset of endovascular procedure., Methods: We performed a systematic review and meta-analysis of randomized controlled clinical trials and observational cohorts providing rates of SR with IVT in patients with large-vessel occlusion before the initiation of mechanical thrombectomy. We also performed subgroup analyses according to study type (randomized controlled clinical trials versus observational) and according to the inclusion per protocol of patients with tandem (intracranial/extracranial) occlusions., Results: We identified 13 eligible studies (7 randomized controlled clinical trials and 6 observational cohorts), including 1561 patients with acute ischemic stroke (median National Institutes of Health Stroke Scale score, 17) with large-vessel occlusion. SR following IVT and before mechanical thrombectomy was documented in 11% (95% confidence interval, 7%-16%), with no difference among cohorts derived from randomized controlled clinical trials and observational studies. There was significant heterogeneity across included studies both in the overall analysis and among subgroups (I 2 >84%; P for Cochran Q, <0.001). Higher tissue-type plasminogen activator-induced SR rates were documented in studies reporting the exclusion of tandem occlusions (17%; 95% confidence interval, 11%-23%) compared with the rest (7%; 95% confidence interval, 4%-11%; P for subgroup differences, 0.003)., Conclusions: Pretreatment with systemic thrombolysis in patients with large-vessel occlusion eligible for mechanical thrombectomy results in SR in 1 of 10 cases, negating the need for additional endovascular reperfusion. Tandem occlusions seem to be the least responsive to IVT pretreatment., (© 2017 American Heart Association, Inc.)

Microvascular decompression (MVD) has been confirmed as an effective treatment of trigeminal neuralgia (TN); however, most previous reports just focused on MVD for TN caused by arterial conflict, there is a paucity of information about its use in venous compression causing TN. In the present study, the authors summarize 5-year experience of MVD for primary TN due to venous compression alone. Thirty-four patients with primary TN caused solely by veins underwent MVD. The presenting symptoms, key operative notes, surgical outcomes together with complications were reviewed. Of all the 34 patients, 19 (55.9%) patients occurred as typical TN. The V2 division was the most commonly affected area. Most of the venous conflicts were grade III (20/34, 58.8%). Deep superior petrosal venous system was the most frequent offending vessel (21/34, 61.8%). The venous conflicts were located at the trigeminal root entry zone in 10 (29.4%) patients, the mid cisternal zone in 18 (52.9%) patients, and the porus of Meckel's cave in 11 (32.4%) patients. At the last follow-up, excellent outcome was obtained in 26 (76.5%) patients, 7 (20.6%) patients got good outcome, fair outcome was achieved in 7 (20.6%) patients, and 1 patient unimproved (2.9%). Cerebrospinal fluid leakage was the most common complication (5.9%). In conclusion, MVD is a safe and effective surgical option for TN due to venous compression alone. It is noteworthy to explore the entire nerve and to protect veins as much as possible.

Background: Several intracranial pathologies require opening the Sylvian fissure to be approached, and they are traditionally accessed through the frontal side of the superficial Sylvian veins. The integrated multimaneuver dissecting technique (IMMDT) interchanges the steps with the veins still secured for safe dissection, but the Sylvian fissure is approached from the optimal, safe side with integrated techniques., Objective: To determine whether the 1-way dissection of the Sylvian fissure converts to the more favorable and flexible IMMDT., Methods: The IMMDT for the Sylvian fissure was used on all our patients. The selected subjects (n = 3) had different pathologies, radiological data, and pre- and postoperative clinical data. These subjects were reviewed retrospectively., Results: The 3 patients presented with different pathologies necessitating opening the Sylvian fissure. The Sylvian fissure was not simple in all cases. In all 3 cases, the Sylvian veins and their branches were saved, as confirmed by postoperative images. The patients all had good neurological outcomes, with either stable or improved modified Rankin Scale at the last follow-up., Conclusion: This study demonstrated that the IMMDT is a safe alternative to other ways of opening a Sylvian fissure composed of complex venous anatomy. The IMMDT aligned the fissure in multiple directions to the exposed trajectory, optimized its approach for a flexible, safe dissection, allowed the instruments to work into the Sylvian fissure, and facilitated exposure of the deep part of the fissure for the final dissection, all without scarifying any structure., (Copyright © 2017 by the Congress of Neurological Surgeons)

Recently, time-of-flight (TOF) and gadolinium-enhanced MR angiography (MRA) imaging have been used to demonstrate subacute intramural hematoma in cervical artery dissection and to detect intraplaque haemorrhage. Our aim was to perform an exploratory study to analyse if venous thrombus-related signal changes (potentially showing iso- or hyperintensity) in cerebral venous sinus thrombosis (CVST) could be observed on 3D-TOF MRA imaging. We analysed retrospectively MRIs of CVST patients in whom both contrast-enhanced MR venography (CEMRV) and 3D-TOF sequences were performed in the acute/subacute phase (i.e. < 31 days after symptom onset). The occluded sinus segments were defined on CEMRV. First, analyses of signal changes in occluded venous sinuses segments (defined by and unblinded to CEMRV) on native 3D-TOF images and morphological MRI sequences were performed. Second, a blinded (to CEMRV and other morphological MRI sequences) analysis was performed on 3D-TOF imaging assessing signal changes on 3D-TOF considering all sinus segments. Twenty-five CVST patients were included. 3D-TOF imaging showed signal changes (most often hyperintensity and less often isointensity) in 84% of the occluded sinus segments. Signal changes were observed in 91% of the occluded sinus segments on T1-weighted imaging, in 69% on T2-weighted imaging, in 68% on FLAIR, in 32% on DWI, and in 55% on T2*-weighted imaging. On blinded analysis, sensitivity of 3D-TOF sequences decreased to 80%, whereas specificity was only 65%. Abnormal signal in the venous sinuses on 3D-TOF may possibly help to suspect CVST, especially when CEMRV sequences lack.

Aim: Surgery for intracranial complex vascular malformations can be quite exigent and involves considerable preoperative planning. Here, we present the advantages of using three-dimensional (3D) printed models as a preoperative investigational modality., Material and Methods: 3D printed models were made from thin-slice computed tomography (CT) angiography scans of 6 patients with arteriovenous malformations over an18-month period from August 2015 to December 2016. The locations of the arteriovenous malformations were in the Sylvian fissure in 1 patient, posterior frontal region in 2 patients, subfrontal region in 1 patient, and parietal region in 2 patients. The CT angiography was performed on a 64-slice CT scanner. Thin-slice axial CT sections were acquired and a volume file was created of the arteriovenous malformation and the required skull bones. The file was then transferred to the 3D printer for creating the model., Results: The model depicted the precise nature of the compactness and location of the nidus in relationship to the skull. It was possible to clearly delineate the course, size, and number of feeding vessels and draining veins. The model made identification of the normal and abnormal vessels easier and assisted in the preparation and conduct of surgery. The model was made to scale and was placed beside the surgeon during the operation. The limitation of current technology was that the exact differentiation of arteries and veins by color coding was not possible., Conclusion: 3D printed models can be helpful in getting information regarding the architecture and character of the arteriovenous malformation. The models are cost-effective and easy to build.

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: The superior sagittal sinus and the draining cerebral veins are often encountered during the surgery for parasagittal and falx meningiomas and during the interhemisperic transcallosal approaches. A knowledge about the variations from the normally described anatomy helps in anticipating and avoiding problems related to these structures during surgery., Aim: The normal variations in the disposition of the superior sagittal sinus and the number and direction of the draining veins in the Indian population have been studied., Settings and Design: This is an anatomical study in the fresh cadavers., Materials and Methods: Sixty fresh cadavers were examined in the autopsy theatre of the Forensic Medicine Department of the Hospital between March 2011 and February 2013., Statistical Analysis Used: Epi-Info, MS-Excel, and the Statistical Package for the Social Sciences (SPSS) were used for data analysis., Results: The position of the superior sagittal sinus was variable and was up to within 1cm on either side of the sagittal suture. The origin of the superior sagittal sinus varied from the level of foramen caecum to a little posterior from the foramen caecum. The total length of the superior sagittal sagitttal sinus varied from 321 mm to 357 mm (average length 338.77mm); vertical compartments of the sinus were found in three-fourth of the cases studied. Tributaries were found in the herringbone pattern and varied from 13 to 19 on the right and 14 to 19 on the left. The Rolandic vein was the largest draining vein in most of the cases. The superior sagittal sinus drained predominantly to the right transverse sinus in three-fourth of the cases studied. The position of the torcula was variable; often towards the right side and at a higher level. The central sulcus was 49.93 mm posterior to the coronal suture and 130.78 mm anterior to the lambdoid suture., Conclusions: This is the first study of its kind in Indian population studying the anatomical variations in the anatomy of the superior sagittal sinus that may have a significant bearing on the neurosurgical approaches adopted.

Background: Venous sinus stenting is an emerging treatment for patients with idiopathic intracranial hypertension and evidence of venous stenosis. Stents placed across the transverse and sigmoid sinuses often cover the vein of Labbé (VOL), a major anastomotic vein draining the cerebral hemisphere. The patency of the VOL after stenting and its clinical implications are poorly understood., Methods: A retrospective analysis was performed of a prospectively collected database of patients undergoing venous sinus stenting. Pre- and post-stent angiography were compared to assess changes in VOL patency, clinical and radiographic outcomes., Results: The study cohort comprised 56 patients. The stent covered the VOL in 92.9% of cases. Thirty-two cases with VOL coverage had evaluable angiograms immediately after stent placement. Among these, VOL filled normally in 75.0%, exhibited diminished caliber with normal transit time in 3.1%, filled sluggishly in 18.8%, and was occluded in 3.1%. Follow-up was assessed in patients with at least 3 months' angiographic follow-up (46 patients, mean 7.2 months). Of these, normal filling was seen in 71.7%, diminished caliber in 26.1%, and sluggish filling in 2.2% of cases. Neither stent coverage of the VOL nor its patency immediately after stenting or at follow-up correlated with stent-adjacent stenosis. There were no neurological sequelae from coverage of the VOL or alteration of its drainage pattern., Conclusions: In the majority of venous stenting cases involving the transverse and sigmoid sinuses, the VOL remains widely patent. Complete VOL occlusion rarely occurs after stenting and may not result in clinical sequelae. Stent coverage of the VOL should not deter the therapeutic use of venous sinus stenting., Competing Interests: Competing interests: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

In 1976 an infant boy initially presented with a choroidal vein of Galen malformation (cVOGM). Craniotomy and clipping of the anterior cerebral artery and posterior choroidal arteries was performed, which was reported in the literature 40 years ago. The patient remained asymptomatic until age 42 when he re-presented with an isolated intraventricular hemorrhage. Angiography demonstrated cVOGM with venous sinus occlusive disease leading to venous hypertension and subsequent intraventricular hemorrhage. The angiogram also demonstrated a 'pseudo-nidus' composed of multiple arterial-to-arterial anastomoses that had developed as a result of the original surgical treatment. We embolized a portion of the lesion to reduce the venous hypertension. The patient has been asymptomatic for more than 2 years. To our knowledge, this is the first reported case of a symptomatic neonatal VOGM treated with open surgery that required embolization as an adult for a delayed hemorrhagic presentation., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background: Trigeminal neuralgia (TN) caused solely by venous compression is uncommon. An appropriate vein management protocol for microvascular decompression (MVD) has not been established. We evaluated the management of veins for TN solely due to venous involvement., Method: We analyzed 31 patients with TN in whom only veins were manipulated during MVD. The culprit veins smaller in diameter than the vein of the cerebellopontine fissure (VCPF) were coagulated and divided in 20 patients (divided group), while transposition was performed for larger veins in the remaining 11 patients (non-divided group). Postoperative outcomes were assessed by Barrow Neurological Institute (BNI) pain intensity score and BNI facial numbness score., Results: Preoperative contrast-enhanced T1 spoiled gradient recalled (SPGR) imaging exhibited higher detection rates for veins (93.5%) than non-contrast fast imaging employing a steady-state acquisition image (74.2%). The transverse pontine vein (TPV) was the most frequently involved vessel. All the divided veins were small TPVs except one. The non-divided group included seven cases of large TPVs and four involving the main trunk of the superior petrosal vein or its large tributaries. The median follow-up duration was 33 months. Pain relief was achieved immediately after the surgery in 28 (90.3%) and within a month in the remaining 3 (9.7%) patients. Numbness was present in seven (22.6%) patients at the final follow-up. Recurrence was observed in only two (10.0%) patients in the divided group compared with four (36.4%) patients in the non-divided group. Comparison at the final follow-up revealed that the divided group had superior outcome compared to the non-divided group., Conclusions: Contrast-enhanced T1 SPGR imaging is crucial to detect small veins in the preoperative diagnosis. Division of the culprit veins is recommended if the diameter is smaller than the VCPF as it provides a better outcome and lower recurrence rate than transposition.

Background: There is an ongoing debate about the sitting position (SP) in neurosurgical patients. The SP provides a number of advantages as well as severe complications such as commonly concerning venous air embolism (VAE). The best monitoring system for the detection of VAE is still controversial., Methods: In this retrospective analysis we compared 208 patients. Transesophageal echocardiography (TEE) or transthoracic Doppler (TTD) were used as monitoring devices to detect VAE; 101 cases were monitored with TEE and 107 with TTD., Results: The overall incidence of VAE was 23% (TTD: 10%; TEE: 37%), but the incidence of clinically relevant VAE (drop in end-tidal carbon dioxide above 3 mmHg) was higher in the TTD group (9 out of 17 VAE, 53%) compared to the TEE group (19 out of 62 VAE, 31%). None of the patients with recorded VAE had clinically significant sequelae., Conclusions: In this small sample we found more VAE events in the TEE group, but the incidence of clinically relevant VAE was rare and comparable to other data. There is no consensus in the definition of clinically relevant VAE.

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  The clinical relevance of emissary veins (EVs) is often neglected. However, for posterior fossa approaches, especially in semisitting positions, these transosseous connections become potentially life threatening. Therefore, knowledge of the presence and configuration of EVs is essential in preoperative planning. We report on the use of preoperative computed tomography (CT) imaging techniques to visualize EVs reliably. Methods  A total of 100 consecutive patients were evaluated by helical CT in bone window mode reconstructed using the standard technique (4.5-mm slices) and the high-resolution technique (1 mm) for the posterior fossa. The presence and size of the EVs, their entry point in the sigmoid sinus, their predilection site, and their visibility using either CT technique were evaluated. Statistical analyses included a comparison of the data from both sides of the head. Results  We noted impressive anatomical variations (high standard deviations) in the number, size, and intraosseous length of the EVs among the study population and between the sides (right and left) of an individual patient; however, no statistical significance was observed for any of these parameters. The detection rate of EVs in thin-slice CT scans versus standard CT scans is significantly different ( p  = 0.0001 on both sides). Conclusions  Thin-slice CT is essential in the preoperative planning of posterior fossa approaches to identify the presence and the course of EVs, reducing preventable approach-related morbidity during surgery., (Georg Thieme Verlag KG Stuttgart · New York.)

: Vessel wall magnetic resonance imaging (MRI) is a novel imaging technique that allows the intracranial vessel walls to be imaged directly. This state-of the art imaging modality may potentially change the way aneurysms are evaluated and managed. In this short review we discuss the current knowledge with illustrative cases., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

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.)

The standard anterior transpetrosal approach (ATPA) for petroclival lesions is fundamentally an epidural approach and has been practiced for many decades quite successfully. However, this approach has some disadvantages, such as epidural venous bleeding around foramen ovale. We describe here our experience with a modified technique for anterior petrosectomy via an intradural approach that overcomes these disadvantages. Five patients with petroclival lesions underwent surgery via the intradural ATPA. The intraoperative hallmarks are detailed, and surgical results are reported. Total removal of the lesions was achieved in two patients with petroclival meningioma and two patients with pontine cavernoma, whereas subtotal removal was achieved in one patient with petroclival meningioma without significant morbidity. No patient experienced cerebrospinal fluid leakage. The intradural approach is allowed to tailor the extent of anterior petrosectomy to the individually required exposure, and the surgical procedure appeared to be more straightforward than via the epidural route. Caveats encountered with the approach were the temporal basal veins that could be spared as well as identification of the petrous apex due to the lack of familial epidural landmarks. The risk of injury to the temporal bridging veins is higher in this approach than in the epidural approach. Intradural approach is recommended in patients with a large epidural venous route, such as sphenobasal and sphenopetrosal vein. Navigation via bone-window computed tomography is useful to identify the petrous apex.

Dandy first described the course of the superior petrosal vein (SPV) and its importance during surgery in 1929. Although it has been reported that this vein can be sacrificed without complication, unfavourable outcomes may occur after dividing the SPV. We review these consequences, which may include peduncular hallucinosis and hearing loss, or even hemorrhage, and discuss factors that may contribute to complications. Preservation of the SPV should be attempted whenever possible to increase the safety of surgery., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Understanding the altered physiology following cerebrospinal fluid (CSF) diversion in the setting of adult hydrocephalus is important for optimizing patient care and avoiding complications. There is mounting evidence that the cerebral venous system plays a major role in intracranial pressure (ICP) dynamics especially when one takes into account the effects of postural changes, atmospheric pressure, and gravity on the craniospinal axis as a whole. An evolved mechanism acting at the cortical bridging veins, known as the "Starling resistor," prevents overdrainage of cranial venous blood with upright positioning. This protective mechanism can become nonfunctional after CSF diversion, which can result in posture-related cerebral venous overdrainage through the cranial venous outflow tracts, leading to pathological states. This review article summarizes the relevant anatomical and physiological bases of the relationship between the craniospinal venous and CSF compartments and surveys complications that may be explained by the cerebral venous overdrainage phenomenon. It is hoped that this article adds a new dimension to our therapeutic methods, stimulates further research into this field, and ultimately improves our care of these patients.

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.)

The petrosal approach has been applied for the treatment of many lesions in the posterior fossa, but the location and preservation of the superior petrosal veins (SPVs) during this approach are usually not particularly considered. The authors developed a technique of dural incision with special consideration of the location of the SPVto preserve venous flow during the petrosal approach. The authors describe technical details on how to cut the dura mater and superior petrosal sinus, with special attention to the location of SPV, so that the normal flow of the SPV to the lateral sinus can be preserved. Between July 2007 and March 2014, this technique was used in 45 patients, and no major complications were reported. The SPVs should be considered critical structures in the petrosal approach. Preoperative evaluation of the SPV anatomy should be performed in patients undergoing such surgical treatment, and the dural opening must be performed with special attention to the SPVto avoid intraoperative injury and postoperative complications.

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.)

Background: According to microsurgical principles, the access to deep-seated cerebral lesions should be as atraumatic as possible. Temporary brain retraction is acceptable in certain situations and may be indispensable when the view of the lesion is obstructed., Method: The utility of this method is illustrated in a case of a ruptured middle cerebral artery (MCA) aneurysm. Two temporary aneurysm clips were connected by a braided suture, thus forming a band with two points of attachment. The Sylvian fissure was opened in a standard fashion. Using one clip, the adventitia and arachnoid over the superficial Sylvian vein were grasped firmly enough to mobilize the superficial Sylvian vein. The distal clip was then attached to surrounding drapes, thus granting a direct view of the aneurysm in the depth of the fissure. Retraction with spatula was not necessary. Patency of the superficial Sylvian vein was demonstrated using idocyanine green angiography., Results: We present a simple method for minimally traumatic brain retraction using aneurysm clips attached to the adventitia of Sylvian veins and held back by sutures., Conclusion: The use of clips attached to the adventitia of the superficial Sylvian may be of help in retracting the Sylvian fissure. By virtue of enlarging the field of view into the deep Sylvian fissure, it may be of help in performing retractorless aneurysm surgery.

Objective: The drainage of the superficial middle cerebral vein (SMCV) has previously been classified into 4 subtypes. Extradural procedures and dural incisions during the anterior transpetrosal approach (ATPA) may interrupt the route of drainage from the SMCV. In this study, the authors examined the relationship between anatomical variations in the SMCV and the corresponding surgical modifications to the ATPA that are necessary for venous preservation., Methods: This study included 48 patients treated via the ATPA in whom the SMCV was examined using 3D CT venography. The drainage patterns of the SMCV were classified into 3 types: cavernous or absent (Type 1), sphenobasal (Type 2), and sphenopetrosal (Type 3). Type 2 was subdivided into medial (Type 2a) and lateral (Type 2b), and Type 3 was subdivided into vein (Type 3a), vein and sinus (Type 3b), and sinus (Type 3c). The authors performed 3 ATPA modifications to preserve the SMCV: epidural anterior petrosectomy with subdural visualization of the sphenobasal vein (SBV), modification of the dural incision, and subdural anterior petrosectomy. Standard ATPA can be performed with Type 1, Type 2a, and Type 3a drainage. With Type 2b drainage, an epidural anterior petrosectomy with subdural SBV visualization is appropriate. The dural incision should be modified in Type 3b. With Type 3c, a subdural anterior petrosectomy is required., Results: The frequency of each type was 68.7% (33/48) in Type 1, 8.3% (4/48) in Type 2a, 4.2% (2/48) in Type 2b, 14.6% (7/48) in Type 3a, 2.1% (1/48) in Type 3b, and 2.1% (1/48) in Type 3c. No venous complications were found., Conclusions: The authors propose an SMCV modified classification based on ATPA modifications required for venous preservation.

The authors demonstrate an interhemispheric transchoroidal approach for third ventricular teratoma resection. Interhemispheric dissection exposed the corpus callosum at a length of about 2 cm. A callosotomy was made to enter into the right lateral ventricle. After septal vein ligation, dissection was made of the space between the right fornix and right internal cerebral vein (ICV); thus bilateral fornix and left ICV would be retracted to the left; right choroid plexus, right ICV to the right. By this transchoroidal approach, the foramen of Monro was extended posteriorly, providing enough of a surgical corridor to resect a posteriorly located third ventricular tumor. The video can be found here: https://youtu.be/gIzPiH3zx&#95;o .

In cavernous sinus (CS) surgery, venous complication may occur in some types of venous drainage. The sphenobasal vein (SBV) drains from the superficial middle cerebral vein (SMCV) to the pterygoid venous plexus at the temporal skull base. A frontotemporal epi- and interdural approach (Dolenc approach), which is one of the CS approaches, may damage the SBV's route. We report a case of intracavernous trigeminal schwannoma that contained the SBV and discuss our modified surgical procedure that combined epi- and subdural approaches to preserve the SBV. A 64-year-old man complained of right progressive oculomotor palsy and was referred to our hospital for surgery. MR images revealed a hemorrhagic tumor in the right CS. Three-dimensional venography revealed that the SMCV drained into the pterygoid venous plexus via the SBV. After identifying the first branch of the trigeminal nerve epidurally, we incised the dura linearly along the sylvian fissure and entered the subdural space to visualize the SBV. The incision was continued to the meningeal dura of the lateral wall of the CS along the superior margin of the first branch of the trigeminal nerve, and the Parkinson's triangle was opened from the subdural side. The tumor was grossly totally removed, and the SBV was preserved. In conclusion, a frontotemporal epi- and subdural approach to the intracavernous trigeminal schwannoma can effectively preserve the SBV.

This video demonstrates surgical techniques of the occipital transtentorial approach to a pineal region tumor without using a fixed brain retractor, which may cause functional impairment or even tissue injury to the occipital visual cortex. There are several ways to facilitate retractorless surgery through this approach. A lateral-semiprone positioning of the patient can induce gravity retraction. The brain is relaxed by draining CSF fluid through lumbar drainage or lateral ventricular tap in the case of obstructive hydrocephalus. Dynamic retraction with handheld instruments after extensive dissection of the deep venous system, including basal veins, can provide a sufficient working space. The video can be found here: https://youtu.be/kQvEHiNcRow .

Intracranial dural arteriovenous fistulas (dAVF) with cervical perimedullary drainage, Cognard V, are a surgically challenging rare entity. In this video we show the disconnection of a right tentorial Cognard V dAVF, done through a subtemporal transtentorial approach with the application of indocyanine green video angiography. A 47-year-old man presented with severe tetraparesis. Only partial embolization was possible. An osteoplastic frontotemporal craniotomy was performed to obtain a wide view along with CSF release to safely mobilize the temporal lobe. Neuronavigation was used to detect the fistula and indocyanine to detect the tentorial afferent arteries and to confirm final disconnection. The video can be found here: https://youtu.be/Yr8tAiiHNXU .

Magnetic resonance (MR) venography and computed tomographic (CT) venography are suited for displaying the convexity veins that drain the medial and lateral surfaces of the brain hemispheres. However, such is not the case for the bridging veins of the skull base. Technical factors prevent contrast material-enhanced MR or CT images obtained in standard axial, coronal, and sagittal planes from fully displaying the curved pathways of these clinically important venous structures. This limitation can be overcome by using a reconstruction technique that depicts these venous structures and their interconnections. Curved and multiplanar reformatted images that distill the important venous features often require knowledgeable manipulation of source images by an operator who is familiar with numerous venous variants and their surgical implications. The normal anatomy of the draining veins is detailed-anatomy that radiologists must master before they can show the surgeon the important venous anatomy that is often missing at standard imaging; this information will foster better communication between radiologists and their surgical colleagues. As a practical matter, the skull base veins are arbitrarily subdivided into those that are at greatest risk with the pterional approach and the subtemporal approach, respectively. These approaches can be expanded to define connections between the superficial venous system and the other valveless venous networks that drain the deep portions of the cerebral hemisphere, the scalp, face, muscles of the neck, diploë of the skull, and meninges. As radiologists gain experience, their image interpretations should mature beyond simple analysis of the primary hemodynamic changes induced by intraoperative sacrifice or injury., (©RSNA, 2016.)

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.)

Background: A piezo actuator-driven pulsed water jet (ADPJ) system is a novel surgical instrument that enables dissection of tissue without thermal damage. It can potentially resect intra-axial lesions while preserving neurological function., Objective: To report our first experience of applying an ADPJ system to brain and spinal cord cavernous malformations., Methods: Four patients (2 women and 2 men, mean age 44.5 years) with brain (n = 3) and spinal cord (n = 1) cavernous malformations were enrolled in the study. All surgeries were performed with the aid of the ADPJ system. Postoperative neurological function and radiological findings were evaluated., Results: The ADPJ system was useful in dissecting boundaries between the lesion and surrounding brain/spinal cord tissues. The pulsed water jet provided a clear surgical view and helped surgeons follow the margins. Water jet dissection peeled off the brain and spinal cord tissues from the lesion wall. Surrounding gliotic tissue was preserved. As a consequence, the cavernous malformations were successfully removed. Postoperative magnetic resonance imaging confirmed total removal of lesions in all cases. Preoperative neurological symptoms completely resolved in 2 patients. The others experienced partial recovery. No patients developed new postoperative neurological deficits; facial palsy temporarily worsened in 1 patient who underwent a suprafacial colliculus approach for the brainstem lesion., Conclusion: The ADPJ provided a clear surgical field and enabled surgeons to dissect boundaries between lesions and surrounding brain and spinal cord gliotic tissue. The ADPJ system is a feasible option for cavernous malformation surgery, enabling successful tumor removal and preservation of neurological function.

Background: Although a transvenous route via the ipsilateral inferior petrosal sinus (IPS) is preferred in treating cavernous sinus dural arteriovenous fistula (CSdAVF), this option may be limited if an occluded ipsilateral IPS undermines microcatheter delivery to the cavernous sinus., Objective: To describe our experience with endovascular treatment of CSdAVF complicated by ipsilateral IPS occlusion., Methods: From January 2003 through September 2014, a total of 49 CSdAVFs with ipsilateral IPS occlusion were identified in 49 patients, who then underwent endovascular treatment. Clinical and radiologic data were retrospectively reviewed., Results: Either transvenous (n = 38) or transarterial (n = 11) access was initially elected, the latter reserved for single-hole or dominant arterial feeder fistulas. Access via occluded ipsilateral IPS was usually attempted (n = 34) by transvenous approach, with a 54.3% success rate. Anterior (n = 3) or posterior (n = 1) facial vein was alternatively used. Direct surgical exposure of ophthalmic vein (n = 3) or radiosurgery (n = 4) was performed for access failure or unsuccessful occlusion by other means. In 46 fistulas (93.9%), complete occlusion was achieved, with no procedure-related morbidity or mortality. Postprocedural symptom improvement was noted in all but 2 patients, who separately experienced paradoxical worsening of cranial nerve palsy and access failure., Conclusion: In patients with CSdAVF and ipsilateral IPS occlusion, various treatment strategies may be applied (given angioanatomic suitability), resulting in excellent procedural and short-term follow-up results. Reopening of an occluded IPS is reasonable as an initial access attempt.

Spinal pial arteriovenous fistulas (SPAVFs) are rare lesions that present more frequently in young patients. Lesions located on radiculo-pial arteries without involvement of the anterior spinal artery are even rarer. SPAVFs may present with mass effect, venous congestion or hemorrhage. Most often, treatment is performed either by surgery or endovascularly with fluid embolic material. Use of microcoils has not been reported for this condition.We present two cases of radiculo-pial high-flow SPAVFs in two patients in their early 30 s. One patient presented with abrupt headache without proof of hemorrhage and the other one with trigeminal neuralgia resulting from dilated posterior fossa draining veins remote from the fistula. Both patients were successfully treated with endovascular shunt closure using microcoils with resolution of symptoms and disappearance of the dilated veins at follow-up.With recent advances in microcatheter technology, distal navigation and microcoil embolization offers another option for these cases that may be safer than fluid embolic material., (© The Author(s) 2015.)

Background: We present two rare cases of pineal-region meningiomas. These tumors are the first reported cases of dura-unrelated meningiomas originating from the arachnoid membrane over the vein of Galen (AMG)., Case Description: In Case 1, a 37-year-old woman presented with a progressing headache. Magnetic resonance imaging (MRI) showed a large tumor in the pineal region, displacing the vein of Galen upward. Angiography disclosed occlusion of the vein of Galen, with deep venous flow draining through the veins on the right medial surface of the occipital lobe to the superior sagittal sinus. In Case 2, a 67-year-old man presented with dizziness. MRI demonstrated a large mass in the pineal region, displacing the vein of Galen inferiorly. Angiography disclosed occlusion of the vein of Galen, with deep venous flow draining through the collateral venous channel into the transverse sinus. Both tumors were totally excised (Simpson Grade III for Case 1, Grade I for Case 2) via a left occipital transtentorial approach. No dural attachment was recognized in either case, but the tumor in Case 1 was firmly adherent to the inferior portion of the AMG, while that in Case 2 was attached to the superior portion of the AMG, but remained dissectible., Conclusions: We reported two cases of pineal-region meningiomas originating from the arachnoid membrane over the vein of Galen, resulting in meningioma without dural attachment. These tumors can be totally resected by careful dissection of the tumor from the arachnoid membrane surrounding the vein of Galen.

Clipping of a posterior projecting large posterior communicating aneurysm via transsylvian anterior temporal approach is presented. To expose and clip this large aneurysm, retraction of the temporal lobe is required via the conventional pterional approach. In this video, we demonstrate microsurgical techniques as to how to dissect and mobilize the sylvian veins as well as a bridging vein to the sphenoparietal sinus, and the middle cerebral artery branches to the frontal lobe side. After the microsurgical dissection, a wide anteriolateral temporal space is obtained without significant temporal lobe retraction. The aneurysm was completely obliterated via this approach. The video can be found here: http://youtu.be/vU9Nxm7Yn-A.

Leptomeningeal venous drainage of cranial dural arteriovenous fistulae is the most important determinant of adverse clinical course. Factors that predispose to its occurrence have not been adequately addressed in the literature. In the present study, we investigated the relation of shunt location to the development of leptomeningeal venous drainage, with regard to the bridging veins. Angiographic data of 211 consecutive patients with cranial dural arteriovenous fistulae treated over 19 years were analyzed. Dural shunts with leptomeningeal venous drainage were found in 107 patients; of these, 71 patients had pure leptomeningeal venous drainage (Borden type 3). The angioarchitecture of the shunt, including pattern of arterial feeders, relation with the bridging veins, primary venous drainage, and venous outflow restrictions were recorded. After analysis of the 71 Borden type 3 shunts with exclusive leptomeningeal venous drainage, three patterns emerged. The commonest was the fistula engaging a bridging vein that had lost its connection to the parent sinus into which it previously drained; it was characterized by an arterial network of feeders converging onto the wall of a bridging vein, with leptomeningeal venous reflux. The other patterns were those of "isolated" sinus segment characterized by arterial feeders converging on to the wall of the dural sinus with leptomeningeal venous reflux following the opacification of the sinus and fistulae in the vicinity of the cribriform plate with two subtypes. The main angioarchitectural features of the 36 Borden type 2 shunts with mixed sinusal-cortical venous drainage were the presence of a diffuse arterial network of vessels converging onto a site in the wall of the dural sinus, with leptomeningeal venous reflux following the opacification of the sinus. In this group, four exceptions were noticed with arterial feeders converging onto a bridging vein and having a mixed venous drainage to the cortical venous system and the sinuses. We concluded that the exact location of the shunt with regard to the bridging veins is a key factor in the development of leptomeningeal venous drainage. Cranial dural arteriovenous fistulae (CDAVFs) of either Borden type 2 or 3 do not constitute a homogeneous group. The great majority of these shunts present thrombotic phenomena.

The commonly used Borden and Cognard classification systems for the prediction of clinical behavior of cranial dural arteriovenous shunts focus on the venous drainage, particularly the presence of leptomeningeal venous drainage, and on the direction of flow, particularly the presence of retrograde flow. In addition, the latter includes ectasia and spinal drainage as criteria of two distinct grades. However, none of the above classifications (a) differentiates direct from exclusive leptomeningeal venous drainage, (b) considers cortical venous congestion as a factor potentially associated with an aggressive clinical course, and (c) anticipates ectasia in shunts with a mixed dural-cortical venous drainage (type 2). In this study, we analyzed the angiographic images of 107 consecutive patients having a cranial dural arteriovenous fistula with leptomeningeal venous drainage, based on a newly developed scheme. This scheme, symbolized with the acronym "DES," groups the dural shunts according to three factors: directness and exclusivity of leptomeningeal venous drainage and signs of venous strain. According to the combination of the three factors, eight different groups were distinguished. All analyzed cases could be assigned to one of these groups. Directness of leptomeningeal venous drainage expresses the exact site of the shunt (bridging vein vs sinus wall), whereas exclusivity expresses venous outlet restrictions. All bridging vein shunts had a direct leptomeningeal venous drainage. Almost all bridging vein shunts and all "isolated" sinus shunts had an exclusive leptomeningeal venous drainage. Venous strain, manifested as ectasia and/or congestion, denotes the decompensation of the cerebral venous system due to the shunt reflux. The comparison of the presented concept with the currently used classifications highlighted the advantages of the former and the weaknesses of the latter.

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.)