Angiographic Morphometry of Internal Carotid Artery Circulation in Turkish Children

AIM: Knowledge of cerebrovascular morphology is integral in planning neuroendovascular interventions, especially for procedures involving placement of stents, flow diverters or stentrievers. There is insufficient data on angiographic normative values of cerebral circulation in the pediatric age group since angiograms are uncommonly performed in children except for arteriovenous malformations in which arterial dimensions are larger than normal. We aimed to measure the diameters of internal carotid circulation (ICC) arteries on digital subtraction angiograms of pediatric patients and determine the growth trends. MATERIAL and METHODS: This is a retrospective cross-sectional study measurements of ICC arteries of 64 pediatric patients (4- 122 months) with retinoblastoma undergoing intra-arterial chemotherapy. RESULTS: Petrous, cavernous, supraclinoid and choroidal segments of internal carotid artery (ICA) and anterior cerebral artery (ACA) diameters had significant correlation with age. Most of the growth was noted in the first 36-48 months of life. Middle cerebral artery (MCA) diameter did not show significant correlation with age. 87% of the adult diameter of the MCA was attained in the first 6 months of life. ICC arteries reached 81% to 99% of adult sizes in the first 48 months of life. On the contrary, the main iliac artery was only 59% of the adult diameter at this age group. CONCLUSION: Use of current intracranial stents in children appears tolerable due to the growth pattern of ICC arteries. Based on this data, the current armamentarium of intracranial stents or stent-like devices is sufficient to cover the need in the pediatric population

Cerebrovascular complications of transorbital penetrating intracranial injuries

BACKGROUND: Cerebrovascular trauma secondary to transorbital intracranial penetrating injury (TIPVI) is rare. Relatively benign initial presentation may mask the underlying life-threatening vascular injury in transorbital intracranial penetrations. The aim of this study was to evaluate clinical features and endovascular treatment of TIPVI. METHODS: Six patients with angiographic documentation of TIPVI in subacute/chronic phase were reviewed retrospectively. Five were treated endovascularly; however endovascular treatment was aborted in one and conservative management was pursued. RESULTS: Except for one case presenting with vision loss and mild stroke, no significant neurologic deficit was present. Vascular lesions included two cases of carotid-cavernous fistulas, three traumatic aneurysms of cavernous carotid, anterior and middle cerebral arteries and a unique case of coalescing cavernous aneurysms following a through-and-through injury in which the aneurysms united within the thrombosed cavernous sinus on follow up. Fistulas were treated with covered stents, aneurysms with parent artery occlusion or flow diverters. All patients had uneventful recoveries. CONCLUSION: TIPVI may present in a delayed fashion after a seemingly benign presentation. A high index of suspicion is critical to rule out TIPVI with vascular imaging. Transcatheter angiographic techniques allow for both diagnosis and treatment of TIPVI with favorable results

Stent-Assisted Coiling Of Cerebral Aneurysms With The Neuroform Atlas Stent

Objectives: The Neuroform Atlas stent (AS) is the smallest intracranial stent with an open-cell design. This study reports the first clinical experience with AS. Methods: All intracranial aneurysms treated by stent-assisted coiling using a single AS in a single institution were retrospectively evaluated. Patient demographics, aneurysm characteristics, angles between the parent artery and stented branch, technical success, and clinical and angiographic follow-up were analyzed. Results: Fifty-five consecutive aneurysms treated with AS-assisted coiling were included. Of these, 69.1% were located distal to the circle of Willis. Technical success rate was 100%. The mean diameters of proximal and distal parent arteries were 2.62 mm (range 1.5-4.4) and 1.8 mm (range 0.8-3.5), respectively. Except for a minor stroke in a patient who completely discontinued antiplatelet therapy on postoperative day 4, there were no clinical events with permanent sequelae, and 94.1% of patients had Raymond-Roy score of 1 or 2 aneurysmal occlusion at a mean follow-up duration of 7.9 months. Although the angle between the parent artery and the stented branch increased significantly (p<0.001) with time, the angular change at follow-up was only 16.45 +/- 11.03 degrees and was inversely correlated both with preoperative angle and the diameter of the distal parent artery (r= -0.465 and r= -0.433, respectively, p=0.004 for both). Conclusion: AS-assisted coiling was associated with a favorable early clinical outcome and angiographic results in this series. This stent can be used for distally located aneurysms and results in minimal alteration of the arterial anatomy.Wo

Endovascular Treatment Of Superior Cerebellar Artery Aneurysms

AIM: To present our experience on superior cerebellar artery (SCA) aneurysms treated with embolization by using current endovascular techniques. MATERIAL and METHODS: All SCA aneurysms treated by our endovascular team since 2013 were retrospectively evaluated. Clinical information and angiographic findings on presentation, during treatment and on follow-up were noted. RESULTS: Endovascular treatment was the primary treatment method for SCA aneurysms during the study period. Twenty three patients (15 female, 8 male) with a mean age of 50.6 years, 12 of whom with subarachnoid hemorrhage were treated. Treatments included coiling (56%), stent assisted coiling, stentriever assisted coiling, Y stent assisted coiling and flow diversion with either flow diverter placement or telescopic stenting. Two patients died secondary to consequences of subarachnoid hemorrhage. The outcome of 1 patient was Modified Rankin Scale (mRS) 3 and the outcome of remaining 20 patients was mRS 0. The rates of aneurysm occlusion according to Raymond-Roy classification were: class 1 in 11 patients, class 2 in 6 patients and class 3 in 2 patients on a mean follow-up of 15.3 months. Only one patient required retreatment. CONCLUSION: Current endovascular techniques are able to address the high rate of recanalization and retreatment of SCA aneurysms which are currently the major drawbacks associated with primary coiling when compared with surgical treatment. It remains to be shown if use of these latest techniques are associated with increased risk of thromboembolic events.WoSScopu

Focused RF hyperthermia using magnetic fluids

Heat therapies such as hyperthermia and thermoablation are very promising approaches in the treatment of cancer. Compared with available hyperthermia modalities, magnetic fluid hyperthermia (MFH) yields better results in uniform heating of the deeply situated tumors. In this approach, fluid consisting of superparamagnetic particles (magnetic fluid) is delivered to the tumor. An alternating (ac) magnetic field is then used to heat the particles and the corresponding tumor, thereby ablating it. However, one of the most serious shortcomings of this technique is the unwanted heating of the healthy tissues. This results from the magnetic fluid diffusion from the tumor to the surrounding tissues or from incorrect localization of the fluids in the target tumor area. In this study, the authors demonstrated that by depositing appropriate static (dc) magnetic field gradients on the alternating (ac) magnetic fields, focused heating of the magnetic particles can be achieved. A focused hyperthermia system was implemented by using two types of coils: dc and ac coils. The ac coil generated the alternating magnetic field responsible for the heating of the magnetic particles; the dc coil was used to superimpose a static magnetic field gradient on the alternating magnetic field. In this way, focused heating of the particles was obtained in the regions where the static field was dominated by the alternating magnetic field. In vitro experiments showed that as the magnitude of the dc solenoid currents was increased from 0 to 1.8 A, the specific absorption rate (SAR) of the superparamagnetic particles 2 cm apart from the ac solenoid center decreased by a factor of 4.5, while the SAR of the particles at the center was unchanged. This demonstrates that the hyperthermia system is capable of precisely focusing the heat at the center. Additionally, with this approach, shifting of the heat focus can be achieved by applying different amounts of currents to individual dc solenoids. In vivo experiments were performed with adult rats, where magnetic fluids were injected percutaneously into the tails (with homogeneous fluid distribution inside the tails). Histological examination showed that, as we increased the dc solenoid current from 0.5 to 1.8 A, the total burned volume decreased from 1.6 to 0.2 cm(3) verifying the focusing capability of the system. The authors believe that the studies conducted in this work show that MFH can be a much more effective method with better heat localization and focusing abilities

Tapered Flow Diverters in the Treatment of Intracranial Aneurysms

AIM:To report the initial experience of cerebral aneurysm treatment with Tapered flow diverters (TFDs). MATERIAL AND METHODS: Thirty patients with 34 aneurysms underwent cerebral aneurysm treatment with TFD (Silk, Balt, Montmorency, France) between March 2011 and March 2016. Procedural findings, complications, clinical and imaging follow-up were assessed retrospectively. RESULTS: The patients" mean age was 48 +/- 14.5 years (range, 16-74; 25 females). Aneurysms size ranged from 3 to 35 mm with an average diameter of 13.9 +/- 8.8 mm and a median diameter of 10.5 mm. Technical success rate was 96.6%. Technically, deployment of the device was similar to the non-tapered version and subjectively, it appeared to be easier in the paraophthalmic segment. Permanent morbidity and mortality rates secondary to the procedure were 0%. On clinical follow-up (29 patients, mean 9.3 +/- 9.1 months) there were no clinical untoward events. Imaging follow-up was at or after 6 months (20 patients, mean 12.3 +/- 10 months). Angiographic occlusion rate was 80%. CONCLUSION: TFD is safe to use and effective for the treatment of intracranial aneurysms in this series. The occlusion rate is higher with respect to the previous reports and experience using the non-tapered version. Maintenance of porosity at the transition zone may be the factor underlying the higher occlusion rate. TFD may be preferred especially for arterial segments aneurysms where there is considerable discrepancy in size between the distal and proximal parent artery.WoSScopu

The implications of magnetic resonance angiography artifacts caused by different types of intracranial flow diverters

Abstract Background Serial cerebral angiographic imaging is necessary to ensure cerebral aneurysm occlusion after flow diverter placement. Time-of-flight (TOF)-magnetic resonance angiography (MRA) is used for this purpose due to its lack of radiation, contrast media and complications. The comparative diagnostic yield of TOF-MRA for different flow diverters has not been previously analyzed. Purpose To evaluate the diagnostic accuracy of TOF-MRA in cerebral aneurysms treated w divertersith different flow diverters. Materials and Methods Flow-diverted patients whose cerebral follow-up MRA and digital subtraction angiograms (DSA) were obtained within 6 weeks were retrospectively identified. The DSA (as gold standard) and MRA images of these patients were compared by two readers (blinded to both patient data and endovascular procedure data) for residual aneurysms and the status of the parent artery for each type of flow diverter. In a second group of patients, magnetic susceptibility artifacts were manually measured and compared for different FDs. Results Seventy-six patients (85 aneurysms) were included in group one, and 86 patients (95 aneurysms) were included in group 2. TOF-MRA and DSA showed almost perfect agreement for residual aneurysms (κ = 0.88, p < 0.001) (positive predictive value (PPV) = 1.00, specificity = 1.00, negative predictive value (NPV) = 0.89, sensitivity = 0.89). Intermodality agreement (κ = 0.97 vs. κ = 0.74, p < 0.005) and sensitivity (0.97 vs. 0.77, NPV: 0.96 vs. 0.77) were highest with nitinol stents. MRA and DSA showed no agreement for occluded or stenotic parent vessels (κ = 0.13, p = 0.015, specificity = 0.44, NPV = 1.00, sensitivity = 1.00). Specificity was lower in chromium-cobalt based FDs than in nitinol devices (specificity = 0.08 vs. 0.60). Chromium-cobalt stents generated the largest artifacts (p < 0.005). The size of the device-related artifact, in millimeters, increased in respective order, for the Silk, Derivo, Pipeline and Surpass devices. Conclusion Unlike DSA, TOF-MRA is susceptible to dissimilarities between flow diverters. MRA is not well-suited for research studies comparing different flow diverters. Nitinol FDs appear to be advantageous for TOF-MRA follow-up so as not to miss small aneurysm remnants or clinically relevant parent artery stenosis

Treatment of ruptured blood blister-like aneurysms with flow diverter SILK stents

Introduction Blood blister-like aneurysms (BBAs) are fragile and difficult to treat. Routine surgical and endovascular treatment methods, such as clipping, clip wrapping, primary coiling, or stent assisted coiling, have relatively high morbidity and mortality rates. In this study, we report clinical and angiographic results for treatment of ruptured BBAs using flow diverter stents

Treatment of ruptured blood blister-like aneurysms with flow diverter SILK stents

Introduction Blood blister-like aneurysms (BBAs) are fragile and difficult to treat. Routine surgical and endovascular treatment methods, such as clipping, clip wrapping, primary coiling, or stent assisted coiling, have relatively high morbidity and mortality rates. In this study, we report clinical and angiographic results for treatment of ruptured BBAs using flow diverter stents. Methods We retrospectively reviewed patients who presented with subarachnoid hemorrhages caused by rupture of BBAs and who were treated using flow diverter stents at three neurointervention centers between January 2009 and January 2013. Clinical and angiographic findings, together with the procedural data and follow-up results, are reported. Results 11 patients were identified in this study. BBAs were located on the supraclinoid internal carotid artery (nine patients) and basilar arteries (two patients). Eight patients were treated by implantation of a single flow diverter stent. Two flow diverter stents were telescopically deployed in each of three patients. The procedures were successful in all cases. No acute complications developed in any case. One patient who had an initial Hess-Hunt grade 4 died of septicemia 2 weeks after the procedure (9%). Another patient developed a minor stroke caused by parent artery thrombosis (9%). Control angiographies performed 3 and 6 months post stenting revealed complete occlusion of the aneurysms in all of the remaining nine patients (82%). 10 of the 11 patients (92%) had good clinical outcomes (modified Rankin Scale score <= 2). Conclusions Implantation of flow diverter stents seems to be a safe and feasible alternative for treatment of ruptured BBAs

The Therapeutic Value Of Pro Anthocyanidin In Experimental Cerebral Vasospasm Following Subarachnoid Hemorrhage

AIM: We aimed to examine the basilar artery in an experimental subarachnoid hemorrhage (SAH) model both from the ultrastructural and radiological aspects and tried to evaluate the benefit of proanthocyanidin (PC), an antioxidant matter, in reducing vasospasm. MATERIAL and METHODS: A total of 21 male New Zealand rabbits were divided into three groups after performing angiography. Group I: Control group, Group II: Subarachnoid hemorrhage group, Group III: Subarachnoid hemorrhage and Proanthocyanidin group (100 mg/kg/day). Rabbits were sacrificed on the 5th day after angiography. A segment of the basilar artery, 4 mm in length, was prepared for ultrastructural examination. RESULTS: There was no ultrastructural or radiological abnormality in the basilar artery in Group 1. In the basilar artery digital subtraction angiography (DSA) of Group 2, a statistically significant decrease in basilar artery calibration was found (p0.05). No damage was seen in the basilar artery ultrastructurally. CONCLUSION: Proanthocyanidin with its strong antioxidant effect and possible vasomotor action can significantly attenuate SAH-induced vasospasm.WoSScopu