Hormone Concentration Measurement in Intracranial Dural Arteriovenous Fistulae.

OBJECTIVE: Intracranial dural arteriovenous fistulae (DAVFs) represent a subset of cerebral vascular malformations associated with significant morbidity and mortality. In Japan, DAVF exhibits sex-based differences in anatomical distribution, with female predominance in the cavernous sinus (CS) and male predominance in the transverse sinus (TS). Nevertheless, the pathophysiology of DAVF is not fully understood, and hormonal influences are hypothesized to play a role in its development. This study aimed to investigate changes in the concentrations of sex steroid hormones between intracranial and peripheral sampling sites in patients with CS- and TS-DAVF. METHODS: We recruited 19 patients with CS-DAVF (n = 12) and TS-DAVF (n = 7) in this study. Blood hormone measurements were obtained from peripheral and jugular bulb samples during endovascular intervention. Hormone concentrations were analyzed using enzyme-linked immunosorbent assay kits, and statistical analyses were performed. RESULTS: Our study revealed a higher prevalence of CS-DAVF in females and TS-DAVF in males, which is consistent with previous studies. Estradiol concentration was significantly lower in the jugular bulb compared with in the periphery in both patients with CS- and TS-DAVF. This decrease in estradiol was observed irrespective of the patient's sex and independent of follicle-stimulating hormone levels. CONCLUSIONS: These findings indicate a local decrease in estradiol levels within the intracranial vasculature of patients with DAVF. This suggests a potential multifactorial role of estradiol in the pathomechanism of DAVFs, warranting further investigation to understand its influence on DAVF formation and potential targeted therapies, thereby enhancing patient outcomes.

Evaluation of the differences in pressure applied to the vessel wall by different types of balloon remodeling microcatheters in an experimental model.

BACKGROUND: We examined compliance differences among balloon remodeling microcatheters, which have not been established previously. METHODS: Straight and 120° angulated vascular models were created in a 3 mm diameter tube with 3 mm hole (vascular model A), a tube with a 4 mm hole (vascular model B), and a 4 mm diameter tube (vascular model C). We compared the pressure exerted when each balloon was herniated 1 or 2 mm between three compliant balloons (SHOURYU SR, TransForm C, and Scepter C) and four super-compliant balloons (HyperForm, SHOURYU HR, TransForm SC, and Scepter XC). RESULTS: In vascular model A, there was a significant difference in the pressure exerted by compliant balloons and super-compliant balloons in both the straight and angulated models. In the straight model (1 and 2 mm), the lowest pressure was exerted by HyperForm (super-compliant balloons group) and SHOURYU SR (compliant balloons group). The lowest pressure was exerted in the angulated model by HyperForm (super-compliant balloons group) and Scepter C (compliant balloons group). The Scepter balloon exerted higher pressure in the straight model than other balloon remodeling microcatheters but less in the angulated model. In vascular model B, the pressure decreased in all balloons compared with model A. In vascular model C, the pressure increased in all balloons compared with model A. CONCLUSIONS: Pressure differed across balloon remodeling microcatheters. In addition, vessel shape and diameter, and hole size, affected the results. Our findings can help select balloon remodeling microcatheters.

Anterior Communicating Artery Aneurysm with a Peculiar Angiographic Appearance: A Case Study.

We describe a case of pulsatile anterior communicating artery aneurysm (A-com AN) with a peculiar angiographic appearance. An 81-year-old man was referred to the department of neurosurgery for a large A-com AN artery aneurysm, which was detected incidentally. The patient hoped not to be treated but to be followed up. After 4 months, magnetic resonance imaging (MRI) revealed the presence of a cerebral edema and hematoma around the aneurysm, and partial thrombus in the upper wall of the aneurysm was suspected. Based on these findings, the patient underwent an immediate coil embolization a day after admission. However, the portion of the neck remnant increased in size after the first procedure. Therefore, 8 months after the initial procedure, he was treated with stent coil embolization. Contrary to the first procedure, angiographic evaluation revealed an active pulsating aneurysm. Moreover, MRI revealed the presence of a partial thrombus in the upper neck segment of the aneurysm, with an intensity that changed over time. The patient underwent cautious treatment and was discharged without any symptoms. This is the first case study to reveal an A-com AN with active pulsation and the relationship between the pulsatile portion of the aneurysm and thrombosed portion by MRI.

Analysis of relationship between superior hypophyseal artery visualization and preservation and postoperative visual field deficit in paraclinoid aneurysm.

Direct surgery for paraclinoid aneurysms can result in visual field deficit owing to compromised blood flow to the superior hypophyseal artery (SHA). However, it is rarely visualized in angiography, and discussions regarding its preservation in the field of neuro-endovascular treatment are limited. Biplane angiographic suite with high spatial resolution has been used at our institution since 2014. Since then, there were a few cases where SHAs could be visualized via digital subtraction angiography. We retrospectively analyzed the relationship between the presences and abscence of SHAs in paraclinoid aneurysms and post-procedural visual field deficit. Sixty-three paraclinoid aneuryms treated by neuro-endovascular procedure in 2014-2018 at our neurosurgery department were analyzed. Pre- and post-procedural multiplanar reconstruction imagings of three-dimensional rotation angiography were analyzed to retrospectively investigate the SHAs. SHAs were visualized in 26 patients (41%) and the median number of pre-procedurally visualized SHAs was 0 (interquartile range 0-1). Their origins were the aneurysmal necks in 11 patients (42%). In two of the 11 cases, they were noticed before coil embolization and were able to be preserved after the procedure. In the remaining nine cases, they were not pre-procedurally detected, and coiling was normally conducted. Visual field deficit occurred in one of these nine cases, but symptoms were transient, and the patient fully recovered. Because SHAs could be visualized in >40% cases and no visual field defects occurred in cases that SHAs could be identified and preserved preoperatively, we recommend their preservation during coil embolization for paraclinoid aneurysms.

Development and clinical evaluation of a contactless operating interface for three-dimensional image-guided navigation for endovascular neurosurgery.

PURPOSE: In endovascular neurosurgery, the operator often acquires three-dimensional (3D) images of the cerebral vessels. Although workstation reoperation is required in some situations during treatment, it leads to time loss because a sterile condition cannot be maintained and treatment must be temporarily interrupted. Therefore, a workstation reoperating system is required while maintaining the desired sterility. METHODS: A contactless operating interface using Kinect to control 3D images was developed via gesture recognition for endovascular neurosurgery and was applied to a 3D volume rendering technique (VRT) image reconstructed at the workstation. The left-hand movement determines the assigned functions, whereas the right-hand movement is used like a computer mouse to pan and zoom in/out. In addition to the interface, voice commands were used and assigned to digital operations, such as image view changes and mode signal changes. RESULTS: This system was used for the actual endovascular treatment of cerebral aneurysms and cerebral arteriovenous malformations. The operator and gesture were recognized without any problems. Using voice operation, it was possible to expeditiously set the VRT image back to the reference angle. Furthermore, it was possible to finely adjust gesture operations, including mouse operation, and treatment was completed while maintaining sterile conditions. CONCLUSION: A contactless operating interface was developed by combining the existing workstation system with Kinect and voice recognition software, allowing surgeons to perform a series of operations, which are normally performed in a console room, while maintaining sterile conditions.

Short-segment Internal Trapping for Symptomatic Thrombosed Large Fusiform Vertebral Artery Aneurysms (Bird's Nest Trapping): A Technical Note.

Internal trapping with coils is an established treatment of symptomatic large non-branching thrombosed fusiform vertebral artery aneurysms (VAA). However, when perforators arise near the aneurysm neck, parent artery occlusion has a high risk of causing medullary infarction. As an alternative treatment, we performed short-segment internal trapping of the artery using n-butyl-2-cyanoacrylate (NBCA) and coils (bird's nest trapping). Before treatment, perianeurysmal perforators are carefully detected using high-resolution three-dimensional rotational angiography (3DRA). Double microcatheters are advanced to the distal portion of the aneurysm through a balloon guiding catheter where coils are deployed without tight packing. Then, NBCA is injected into the coil mass, taking care to preserve perforators and significant branches. The same maneuver is repeated in the proximal portion of the aneurysm. Coil placement is avoided within the middle of the aneurysm; however, if necessary, only a small number of coils are placed to prevent worsening of mass effect. Two quinquagenarian males presented with a large thrombosed fusiform VAA that caused symptoms due to mass effect. In each case, perforators arose from the parent artery and short-segment internal trapping with NBCA and coils was performed. Symptoms improved after treatment and follow-up imaging confirmed aneurysm shrinkage with no long-time recurrence. In symptomatic large fusiform VAAs where the distance from the lesion to important perforators is extremely short, internal trapping using a combination of NBCA and coils can be more useful than conventional internal trapping.

Direct Vertebral Artery Puncture During Open Surgery for the Endovascular Treatment of a Recurrent Vertebro-Vertebral Arteriovenous Fistula.

BACKGROUND: Vertebro-vertebral arteriovenous fistula (VVAVF) is a condition in which there is an arteriovenous shunt directly connecting the extracranial vertebral artery to the vertebral venous plexus. Many reports have described fistula occlusion or vertebral artery trapping as treatments for VVAVF. Here, we describe a case in which endovascular treatment for recurrent VVAVF using a transfemoral approach was unsuccessful; thus, the vertebral artery (VA) was directly punctured during open surgery and the treatment was successful. CASE DESCRIPTION: The patient was a 47-year-old female who had undergone endovascular treatment for VVAVF. The patient developed subarachnoid hemorrhage. Digital subtraction angiography revealed a left VVAVF. The left VA was trapped with coils at the C2 and C3 levels and an arteriovenous shunt formed from the VA between the 2-coil mass to the vertebral venous plexus. In addition, reflux was observed in the spinal vein. Endovascular treatment was attempted with a transfemoral approach, but we could not reach the shunt. Five days post-treatment, the patient had a second subarachnoid hemorrhage and surgery was performed to occlude the radiculomedullary vein; however, residual reflux went into the spinal vein from another spinal level. Later, the VA was directly punctured and treated with N-butyl cyanoacrylate, and the shunt disappeared. CONCLUSIONS: Direct puncture of the vertebral artery was useful in this case, where it was difficult to reach the lesion. Although direct VA puncture is associated with more complications than the transfemoral or transbrachial approach, it may be an option when other methods are difficult.

A case of internal trapping to a thrombosed giant rapidly growing aneurysm at the posterior cerebral artery.

We describe a case of internal trapping including the vasa vasorum for a thrombosed giant rapidly growing posterior cerebral artery aneurysm and performing a detailed analysis. A 48-year-old woman was followed up in our hospital for a thrombosed large posterior cerebral artery aneurysm located in the P2 segment. She initially presented after experiencing a sudden headache on two occasions. Head computed tomography and magnetic resonance imaging indicated a larger aneurysm than before. Digital subtraction angiography with balloon occlusion test was assessed, and internal trapping was sequentially conducted. We detected that the vasa vasorum originated from the posterior temporal artery. Therefore, we embolized the posterior temporal artery including the vasa vasorum using N-butyl-2-cyanoacrylate and Lipiodol. Next, the anterior temporal artery was embolized with N-butyl-2-cyanoacrylate and Lipiodol, posterior temporal artery P3 segment and the aneurysm and finally the proximal P2 segment were embolized with coils. Final vertebral and internal carotid angiography showed complete obliteration of the aneurysm. On the day after the procedure her paresis worsened and she developed left upper quadrantanopia, however was finally discharged with no hemiparesis. We reported a case of a rapidly growing thrombosed giant posterior cerebral artery aneurysm treated by parent artery occlusion including the vasa vasorum with detailed image analysis.

Factors influencing blood flow resistance from a large internal carotid artery aneurysm revealed by a computational fluid dynamics model.

Hyperperfusion syndrome occurs after treatment of a large or giant cerebral aneurysm. Recently, flow-diverter stent placement has emerged as an effective treatment method for a large cerebral aneurysm, but postoperative ipsilateral delayed intraparenchymal hemorrhage occurs in a minority of cases. The mechanism underlying delayed intraparenchymal hemorrhage is not established, but one possibility is hyperperfusion syndrome. The incidence of delayed intraparenchymal hemorrhage appears to be higher for giant aneurysms; hence, we speculated that large/giant aneurysms may create flow resistance, and mitigation by flow-diverter stent deployment leads to hyperperfusion syndrome and delayed intraparenchymal hemorrhage. The purpose of this study was to identify aneurysm characteristics promoting flow resistance by the analysis of pressure loss in an internal carotid artery paraclinoid aneurysm model using computational fluid dynamics. A virtual U-shaped model of the internal carotid artery siphon portion was created with a spherical aneurysm of various angles, body diameters, and neck diameters. Visualization of streamlines, were calculated of pressure loss between proximal and distal sides of the aneurysm, and vorticity within the aneurysm were calculated. The pressure loss and vorticity demonstrated similar changes according to angle, peaking at 60°. In contrast, aneurysm diameter had little influence on pressure loss. Larger neck width, however, increases pressure loss. Our model predicts that aneurysm location and neck diameter can increase the flow resistance from a large internal carotid artery aneurysm. Patients with large aneurysm angles and neck diameters may be at increased risk of hyperperfusion syndrome and ensuing delayed intraparenchymal hemorrhage following flow-diverter stent treatment.

Cardiac Arrest Induced by Carotid Sinus Reflex Activation During Flow-Diverter Stent Deployment.

BACKGROUND: A 60-year-old female with multiple carotid aneurysms underwent endovascular treatment with a Pipeline Flex embolization device (PED) under local anesthesia via femoral puncture. CASE DESCRIPTION: Cardiac arrest occurred when the delivery systems were pushed to promote adequate opening and apposition of the PED against the vessel wall and was recovered to sinus rhythm in approximately 30 seconds by pulling down the microcatheter. The carotid sinus reflex was suspected as the cause of this temporary asystole. Delivery of the PED was accompanied by application of forward pressure on the delivery system. This resulted in buckling of the delivery systems in the neck and likely excessive pressure on the carotid sinus. The procedure was continued and successfully completed with care not to excessively push the system and with the additional use of atropine. CONCLUSIONS: Although it was a rare complication, the phenomenon and its mechanisms were known in the carotid artery stenting procedure. To the best of our knowledge, this is the first report of cardiac arrest induced by a carotid sinus reflex during PED deployment. It is important for an operator of PED deployment to recognize its possibility. Vital signs should be closely checked during PED deployment, particularly while pushing the catheter.