Pilocytic astrocytoma of the optic nerve with intracystic hemorrhage in an adult: illustrative case.

BACKGROUND: Optic pathway gliomas are uncommon, accounting for 3-5% of childhood brain tumors, and are mostly classified as pilocytic astrocytomas (PAs). PAs of the optic nerve are particularly rare in adults. OBSERVATIONS: The authors presented the case of PA of the left optic nerve in a 49-year-old woman along with detailed pathological and molecular analyses and sequential magnetic resonance imaging. The tumor had progressed during 5 years of follow-up along with cyst formation and intracystic hemorrhage; it had a thick capsule and contained xanthochromic fluid. The boundary between tumor and optic nerve was unclear. B-type Raf kinase (BRAF) V600E point mutations or translocations, IDH1-R132H mutations, loss of alpha-thalassemia/mental retardation X-linked, and 1p/19q codeletion were negative. LESSONS: BRAF alterations in pediatric PAs of the optic nerve are less frequent than those observed in PAs in other lesions; the same molecular pattern was observed in the adult case, without changes in BRAF. Surgical management should be indicated only in cases with severely impaired vision or disfigurement because there is no clear border between the tumor and optic nerve. Further discussion is needed to optimize the treatment for adult optic pathway gliomas, including radiotherapy, chemotherapy, and molecular-targeted therapies, in addition to surgical intervention.

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.

Case-control study of postprocedural arterial puncture site hemorrhage after neuroendovascular treatment.

Puncture site hemorrhage following femoral artery catheterization is a significant cause of morbidity. The aim of this case-control study was to identify predictors of postprocedural arterial hemorrhage at the puncture site. We retrospectively reviewed 255 patients who underwent endovascular treatment at our institution over a 23-month period and classified them into a hemorrhage group and a non-hemorrhage group. Puncture site hemorrhage occurred in 15 patients (5.9%). Clinical factors associated with a significantly increased risk of puncture site bleeding included patients whose postoperative activated clotting time of ≥300 seconds before removal of the sheath (9 patients, 11.8%; P<0.05), those who received triple antiplatelet therapy (n=4, 17.4%; P<0.05) and the group administered heparin postoperatively (7 patients, 13.2%; P<0.05). The effects of low on-treatment platelet reactivity, i.e., P2Y12 reaction units <95%, sheath size, hemostasis method used, and operating time were not clinically significant. Our findings suggest an increased risk of puncture site hemorrhage in patients who either had an activated clotting time ≥300 seconds before the postoperative removal of the sheath, had received triple antiplatelet therapy, or were administered heparin postoperatively.

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.

Midterm Follow-Up of 20 Consecutive Patients with Nonaneurysmal Subarachnoid Hemorrhage of Unknown Origin in a Single-Center: Two Cases of De Novo Development of Dural Arteriovenous Fistula.

BACKGROUND AND PURPOSE: The mechanisms and prognosis of underlying subarachnoid hemorrhage of unknown origin remain unclear. Previous investigators have suggested a relationship between nonaneurysmal perimesencephalic subarachnoid hemorrhage and venous abnormalities like a primitive venous drainage of the basal vein of Rosenthal. We report the outcome of a midterm follow-up of 20 consecutive patients with nonaneurysmal subarachnoid hemorrhage of unknown origin, and 2 patients in whom the development of new dural arteriovenous fistulas after subarachnoid hemorrhage of unknown origin were detected during follow-up. METHODS: All patients who were admitted to our hospital for nontraumatic subarachnoid hemorrhage between April 2008 and March 2016 were retrospectively analyzed. RESULTS: Of 705 patients included in the study, 20 (2.8%) were diagnosed with nontraumatic subarachnoid hemorrhage of unknown origin. During the follow-up periods, there was no rebleeding. Although 18 patients did not show any vascular abnormalities, the other 2 patients were diagnosed with dural arteriovenous fistula. Both fistulas were successfully treated with endovascular embolization. CONCLUSIONS: Subarachnoid hemorrhage of unknown origin had a low incidence rate, and its clinical course was excellent without rebleeding. Although no vascular abnormalities were observed during the patients' initial admission, venous lesions might have been involved in both subarachnoid hemorrhages and delayed dural arteriovenous fistulas. Here, the possible pathogenesis is discussed with a review of the literature.

Feasibility and Safety of Distal and Proximal Combined Endovascular Approach with a Balloon-Guiding Catheter for Subclavian Artery Total Occlusion.

BACKGROUND: Symptomatic subclavian artery total occlusion is widely treated with an endovascular procedure that often results in distal vertebral artery embolism. Therefore, protection devices are important. Establishing a filter or balloon device in the vertebral artery can protect against this distal embolism. However, the use of embolic protection devices is not easy, and it makes the procedure more complicated. Here, we report a case of symptomatic subclavian artery total occlusion that was treated successfully with a balloon-guiding catheter and the pull-through technique. CASE DESCRIPTION: A 67-year-old man developed intermittent motor weakness in his left arm. Aortic angiography demonstrated a complete occlusion of the left proximal subclavian artery and a retrograde flow through the left vertebral artery to the distal brachial artery. In this case, we used a balloon-guiding catheter and the pull-through technique to prevent distal embolism. The balloon-guiding system was useful not only for embolic protection but also for scaffold during excavation and for the centering effect against invisible vessels. The pull-through technique enabled our devices to deliver easily and smoothly. The patient was treated successfully without complications. CONCLUSIONS: The distal and proximal combined endovascular treatment with a transbrachial balloon-guiding catheter is a beneficial treatment option for patients with subclavian artery total occlusion.