Recurrent epistaxis from inflamed granulated tissue and an associated pseudoaneurysm of the internal carotid artery: case report

Background: Chronic inflamed tissue in nasal cavity is a rare complication of transsphenoidal approach (TSA). Inflamed tissue is rich in blood vessels, which can lead to frequent nosebleeds. In addition, chronic inflammation can cause pseudoaneurysm, whose rupture results in massive epistaxis. There have been few reported cases of pseudoaneurysm of ICA occurring more than 10 years after TSA surgery. Case presentation: We report a case of a patient who had recurrent epistaxis for over a decade after TSA surgery, and analyzed the causes of the nosebleeds. The aspect of occurrence of the nosebleeds and the result of biopsy and imaging tests suggest that the nosebleeds were due to chronic inflamed tissue and an associated pseudoaneurysm. The rupture of pseudoaneurysm recurred after treatment with stent placement, and brain abscess was developed. After removing the inflamed tissue by endoscopic resection, the patient no longer had recurrence of ruptured pseudoaneurysm or nosebleeds. Conclusions: In patients with recurrent nosebleeds, the possibility of intranasal inflammation and subsequent pseudoaneurysm should be considered. Therefore, people who consistently have epistaxis after TSA, even if the bleeding is not in large amount, should be actively screened and treated for nasal chronic inflammation.ope

The Effect of Nitrogen and Sulfur Dopants on the Visible Light Photocatalytic Activity of TiO2

학위논문 (석사)-- 서울대학교 대학원 : 재료공학부, 2014. 2. 곽승엽.The effects of nitrogen and sulfur dopants at inside and surface of TiO2 was discussed separately to investigate the reasons for the high visible light photocatalytic activity of nitrogen and sulfur codoped TiO2 (NST). Crystallization and formation of anatase phase of NSTs were observed by X-ray diffraction spectra and high resolution-transmittance electron microscopy (HR-TEM). X-ray photoelectron spectroscopy (XPS) analysis revealed that nitrogen and sulfur atoms are doped at oxygen site of inside of TiO2 while nitrogen is located in substitutional site and sulfur shows shifted sulfide peak on the surface of TiO2. The quantity of dopants at oxygen site is significantly decreased with crystallization of NST at high temperature (> 350 C). As the thermal treatment progressed, sulfur dopants at oxygen site move to surface of NST and finally form sulfate bonding while total amount of sulfur dopants of NST is maintained. UV-Vis diffuse reflectance spectroscopy (DRS) showed that both dopants on the surface and inside of TiO2 reduce band gap energy. The photocatalytic activities of NST were evaluated by the degradation of rhodamine B (RhB) under visible light and UV light irradiation. Results showed that both of dopants in inside of TiO2 and surface of TiO2 enhance visible light photocatalytic activity and act as recombination centers simultaneously. When visible light is irradiated, nitrogen dopants at oxygen site in inside of the TiO2 enhance solution bulk reaction because they reduce band gap energy. Sulfide on the surface of NST enhances the surface reaction by interacting with organic dyes. As-synthesized NST has 7.7 times faster degradation rate than that of P25 under visible light irradiation.CONTENTS ABSTRACT...............................................................................................................i CONTENTS....................................................................................................................iv 1. Introduction .................................................................................................................1 2. Experimental .............................................................................................................14 2.1. Materials ……..…………………………………………………………….……..14 2.2. Preparation of nitrogen and sulfur codoped TiO2 (NST) .......................................14 2.2.1 Step 1: Synthesis of nitrogen and sulfur codoped TiO2 (NST-As) by solvothermal treatment ………………………………….………............................15 2.2.2. Step 2: Post thermal treatment process ........................................................15 2.3. Characterization of synthesized NSTs …………………………….……………19 2.3.1. Crystal structure crystal size and surface area …………………...……………19 2.3.2. Quantity and chemical state of dopants .............................................................20 2.3.3. Thermal behaviors …………………….............................................................20 2.3.4. Band gap energy measurement ..........................................................................21 2.4. Photocatalytic activity and adsorptivity evaluation ......…………………………..22 2.4.1. Rhodamine B degradation test under visible light irradiation ……….............22 2.4.2. Rhodamine B degradation test under UV light irradiation ………....................23 2.4.3. Adsorption test in rhodamine B and methylene blue solution ……………….23 3. Results and Discussion ................................................................................28 3.1. Characterization of synthesized NSTs ……………………………………….….....28 3.1.1. Crystal structure crystal size and surface area ………………………………28 3.1.2. Quantity and chemical state of dopants .............................................................36 3.1.3. Thermal behaviors ………………….................................................................42 3.1.4. Band gap energy …………................................................................................44 3.2. Photocatalytic activity and adsorptivity ………..…………………..……….……....47 3.2.1. Mechanisms of degradation of rhodamine B by pure TiO2 …...........................47 3.2.1. Visible light photocatalytic activity of NSTs ………………..........................49 3.2.2. UV light photocatalytic activity of NSTs ………………………..……………56 3.2.4. Adsorptivity of NSTs in methylene blue solution ………………………….....59 3.2.5. Mechanisms of degradation of rhodamine B by NSTs ……………………….62 4. Conclusions ………….………………………………………………………….......64 5. References ….............................................................................................................66 KOREAN ABSTRACT ……………………………………...……………………….70 ACKNOWLEDGEMENT……………………………………………………………72Maste

Analysis of neointima development in flow diverters using optical coherence tomography imaging.

BACKGROUND: Flow diverters are used for the treatment of intracranial aneurysms. Surface modification may decrease the thrombogenicity of flow diverters but the details are unknown. Optical coherence tomography (OCT) is an intravascular imaging test with high resolution which identifies neointimal growth over stents. We compared the development of neointima in a flow diverter and stents with and without surface modification in a swine model. METHODS: In this study we implanted four devices (two in each carotid artery) in four pigs. The devices used were the Pipeline Flex embolization device (PED Flex, n=6), PED with Shield technology (PED Shield, n=6), and Solitaire AB (n=4). Serial carotid angiographic and OCT images were obtained on days 0, 7, 14, and 21. The data analyzed included: neointimal area (lumen area - stent area), neointimal ratio ([lumen area - stent area]/stent area), and the neointimal thickness ratio (minimum neointimal thickness/maximum neointimal thickness). RESULTS: There was no significant difference in where neointima formation was initiated in relation to the implanted device (distal vs middle vs proximal). The PED Shield had a trend towards earlier endothelial formation at day 7. By day 21 the neointimal ratio was significantly higher for the PED Flex and PED Shield devices than for Solitaire (p<0.05 and p<0.01, respectively). The neointimal thickness ratio was significantly higher with PED Shield than with PED Flex and Solitaire (p<0.05 and p<0.01, respectively). CONCLUSIONS: OCT enabled us to follow and compare in vivo the development of neointima over implants. PED Shield showed a similar neointimal volume to PED Flex and more concentric neointima.ope

Preliminary outcomes of single antiplatelet therapy for surface-modified flow diverters in an animal model: Analysis of neointimal development and thrombus formation using OCT

OBJECTIVE: To evaluate the rate of neointimal development and thrombus formation of surface-modified flow diverters in single antiplatelet therapy (SAPT) using optical coherence tomography (OCT) in a porcine model. METHODS: We divided 10 experimental pigs into two groups. One group (n=6) received dual antiplatelet therapy (DAPT) and the other group (n=4) received SAPT. Four stents (two per carotid artery) were implanted in both groups. The stents used were the Pipeline Flex embolization device (PED Flex), Pipeline Flex with Shield technology (PED Shield), and the Solitaire AB stent. All animals underwent weekly angiography and OCT. The OCT data were analyzed using the following measurements: neointimal ratio ((stent - lumen area)/stent area), stent-coverage ratio (number of stent struts covered by neointima/total stent struts), and the presence or absence of thrombus formation per 1 mm cross-section. RESULTS: PED Flex and Shield in the SAPT group had higher neointimal ratios than in the DAPT group (P<0.001, respectively). In the DAPT group, the speed of endothelial growth on day 7 in the PED Shield group was higher than that in the PED Flex group (P<0.001). In the SAPT group, PED Flex demonstrated significantly more thrombus formation on day 7 than PED Shield (P<0.001). CONCLUSIONS: The PED Shield stent showed faster endothelial growth than the other devices and comparable neointimal volume. There was significantly less thrombus formation on PED Shield than PED Flex when using SAPT in a porcine model.ope

Treatment strategies of ruptured posterior inferior cerebellar artery aneurysm according to its segment

BACKGROUND: The aim of this study was to evaluate the clinical outcomes between endovascular treatment (EVT) and surgery of the ruptured posterior inferior cerebellar artery (PICA) aneurysms and suggest proper management strategies according to the PICA segment. METHODS: We retrospectively analyzed clinical and radiological data of patients with ruptured PICA aneurysms who underwent surgery or EVT from three different institutes. Clinical outcomes were evaluated by mRS. RESULTS: We collected 39 consecutive patients with 39 ruptured PICA aneurysms; 26 patients were with proximal segment aneurysm and 13 patients were with distal. Of the 26 proximal PICA aneurysms, 20 aneurysms were treated with EVT and 6 aneurysms were treated with surgery. EVT seemed to have more favorable clinical outcome (mRS 0-2; mean mRS, 1.75 for EVT vs 3.50 for surgery, P = 0.152). Of the 13 distal PICA aneurysms, 7 aneurysms were treated with EVT and 6 were treated with surgery. Surgery showed more favorable clinical outcome (mean mRS, 2.63 for EVT vs 0.33 for surgery, P = 0.023) and lower procedure-related complication rate (42.9% for EVT vs 0% for surgery, P = 0.046) than EVT. CONCLUSIONS: For the treatment of ruptured PICA aneurysms, EVT seemed to have more favorable outcomes for proximal segment, while surgery showed more favorable outcomes for distal segment. Additional experience and follow-up are needed in a larger series to state the efficacy of this strategy.ope

Wingspan Stenting for Symptomatic Severe In-Stent Stenosis of a Closed-Cell Stent after Stent-Assisted Coiling of a Ruptured Intracranial Aneurysm

We report the 3-year follow-up result of Wingspan intracranial stenting for symptomatic severe in-stent stenosis after stent-assisted coiling (SAC) for a ruptured left distal internal carotid artery (ICA) aneurysm. A middle-aged male patient visited our hospital for in-stent stenosis of a stent that was placed to treat a ruptured ICA aneurysm. Routine follow-up cerebral angiography, 1 year after SAC, showed in-stent stenosis around the distal markers of the inserted stent at the left M1 proximal segment. Six months later, he developed right dysesthesia. We performed intracranial stenting with Wingspan stent for the in-stent stenosis. Follow-up digital subtraction angiography performed 1 year after the Wingspan stenting showed good patency of the ICA and middle cerebral artery flow without evidence of restenosis. At 3-year follow-up, magnetic resonance angiography showed sufficient middle cerebral artery flow although the stenting segment could not be visualized clearly. Wingspan stenting might be a feasible option in patients with iatrogenic intracranial stenosis resulting from in-stent stenosis who experience the progression of intracranial stenosis with manifestation of neurological symptoms despite dual anti-platelet therapy.ope

Y-stent-assisted coiling with Neuroform Atlas stents for wide-necked intracranial bifurcation aneurysms: A preliminary report

Objective: To report our experience on Neuroform Atlas Y-stenting for coiling of unruptured wide-neck bifurcation aneurysms. Methods: From March 2018 to January 2021, we treated 473 aneurysms in 436 patients with coil embolization, of which 15 cases with wide-necked bifurcation aneurysms were treated by Y-stent-assisted coiling with two Neuroform Atlas stents. We retrospectively reviewed the characteristics of patients and aneurysms, procedure-related complications, radiographic results, and clinical outcomes. Results: All 15 cases using Neuroform Atlas Y-stenting were successful. Patients included 6 men and 9 women with a mean age ± standard deviation of 56.4±6.6 years. The mean dome and neck sizes were 6.4±3.1 mm and 4.7±1.8 mm, respectively. Immediate post-procedural angiograms showed complete occlusion in 46.7%, neck remnant in 13.3%, and incomplete occlusion in 40% of cases. No treatment-related morbidity or mortality occurred in any patients. All patients had good clinical outcomes (Glasgow Outcome Score 5) at both discharge and during a mean 12.3-month (range 1-28 months) follow-up. All aneurysms showed improved or stable occlusion on follow-up imaging. Further, the latest follow-up angiography showed complete occlusion in 73.3%, neck remnant in 6.7%, and incomplete occlusion in 20%. Conclusions: Y-stent-assisted coiling with Neuroform Atlas stents might be a feasible and safe option for wide-necked bifurcation aneurysms.ope

Outcomes of Stent-Assisted Coiling Using the Neuroform Atlas Stent in Unruptured Wide-Necked Intracranial Aneurysms

Objective: Although stent-assisted coiling (SAC) has been reported to be safe and effective in treating wide-necked aneurysms, the technique has procedure-related complications. Thus, we reported our experiences of SAC using the Neuroform Atlas stent in treating wide-necked aneurysms and evaluated the incidence of and risk factors for procedure-related complications. Methods: From March 2018 to August 2019, we treated 130 unruptured wide-necked aneurysms in 123 patients with Neuroform Atlas stents. Angiographic results and clinical outcomes were reviewed retrospectively. Clinical and angiographic follow-up were performed in all cases (mean, 12.4 months) after the procedure. Results: There were eight cases (6.2%) of procedure-related complications (two dissections, five thromboembolisms, and one hemorrhage) and two (1.5%) of delayed complications (one ischemia and one hemorrhage). There was one case (0.8%) of failure of stent deployment and one (0.8%) of suboptimal positioning of the stent. Follow-up angiography showed complete obliteration in 103 (79.2%), residual neck in 16 (12.3%), and residual aneurysm in 11 cases (8.5%). Aneurysm locations in the middle cerebral artery (odds ratio [OR], 2.211; p=0.046) and the anterior communicating artery (OR, 2.850; p=0.039) were associated with procedurerelated complications on univariate analysis. However, no independent risk factor for procedure-related complications was noted in multivariate analysis. Conclusion: The Neuroform Atlas showed a high rate of technical success. Good clinical and radiographic outcomes in early follow-up suggests that the device is feasible and safe. SAC of aneurysms on the middle cerebral artery or anterior communicating artery may require more attention to prevent possible procedure-related complications.ope

An Onyx tunnel: reconstructive transvenous balloon-assisted Onyx embolization for dural arteriovenous fistula of the transverse-sigmoid sinus

Transvenous embolization is an effective method for treating dural arteriovenous fistulas (DAVFs) of the transverse-sigmoid sinus (TSS). However, in cases of complicated DAVFs, it is difficult to preserve the patency of the dural sinus. The authors describe the technical details of a new reconstructive technique using transvenous balloon-assisted Onyx embolization as another treatment option in a patient with an extensive and complex DAVF of the left TSS. A microcatheter and compliant balloon catheter were navigated into the left internal jugular vein and placed at the distal end of the DAVF in the transverse sinus. The microcatheter was placed between the vessel wall of the TSS and the balloon. After the balloon was fully inflated, Onyx-18 was injected at the periphery of the balloon in a slow, controlled, progressive, stepwise manner; the balloon and microcatheter were simultaneously withdrawn toward the sigmoid sinus, with Onyx encompassing the entirety of the complex DAVF. The Onyx refluxed into multiple arterial feeders in a distal-to-proximal step-by-step manner, ultimately resulting in an Onyx tunnel. The final angiography study revealed complete obliteration of the DAVF and patency of the TSS. The Onyx tunnel, or reconstructive transvenous balloon-assisted Onyx embolization technique, may be an effective treatment option for large, complex DAVFs of the TSS. This technique may provide another option to facilitate the complete obliteration of the DAVF while preserving the functional sinus.ope

A comparison between the new Low-profile Visualized Intraluminal Support (LVIS Blue) stent and the Flow Redirection Endoluminal Device (FRED) in bench-top and cadaver studies.

OBJECT: The aim of this study is to demonstrate the differences between the new Low-profile Visualized Intraluminal Support (LVIS Blue) stenting device and the Flow Redirection Endoluminal Device (FRED) using a series of bench-top evaluations and optical coherence tomography (OCT) images in a cadaveric preparation of the basilar artery. METHODS: The first part of the evaluation was bench-top microscopic documentation of metal coverage for LVIS Blue and FRED stents. OCT images of the cerebral vessels and deployed stents were acquired using OCT intravascular imaging. The stents were deployed from the left posterior cerebral artery to the basilar artery in a fresh frozen cadaver. Wall apposition and the relationship to jailed perforators were evaluated. RESULTS: The metal coverage along the inner curves of the LVIS Blue stent was similar to that along the outer curves of the FRED stent. The LVIS Blue stent cell size was compatible for crossing with the tested microcatheters after deployment of the stent. The LVIS Blue stent showed better wall apposition and less coverage of the perforator than the FRED stent in the cadaver experiment. CONCLUSIONS: LVIS Blue has a good crossing profile for microcatheters, better wall apposition, and less perforator coverage than FRED. These are desirable features in territories with high densities of perforators such as the posterior circulation.ope