Coil Compaction Research Articles

Safety and efficacy of stent-assisted coiling ruptured intracranial aneurysms: A single-center experience

ABSTRACT Objective: Endovascular coiling is a minimally invasive method to manage intracranial aneurysms. However, patients who undergo stent-assisted coiling (SAC) for acutely ruptured intracranial aneurysms need dual antiplatelet treatment. We reported our experience and outcomes of SAC for ruptured intracranial aneurysm. Materials and Methods: We retrospectively collected data on procedure-related complications, rates of aneurysm rebleeding and recurrence, and clinical outcomes of patients with ruptured aneurysms managed by SAC over 2 years. Results: Among the 17 patients included in this study, there were 14 (82.4%) women and 3 (17.6%) men, with a mean age of 58.59 years (standard deviation = 13.57; range: 40–82 years). There were no periprocedural hemorrhagic complications and no aneurysm rebleeding before discharge. However, two patients developed acute brain infarction because of symptomatic vasospasm. Linear regression revealed significant associations of posterior circulation involvement with the Glasgow Outcome Score and modified Rankin Scale (mRS) at discharge and 6 months after. Besides, Hunt and Hess grade ≥3 has a significant association with mRS at discharge, 6 months, and 1 year after. Conclusion: SAC for ruptured aneurysm was technically feasible and did not carry an additional risk of postoperative aneurysm rebleeding secondary to antiplatelet treatment. Moreover, it had relatively low rates of aneurysm regrowth and coil compaction. Therefore, it can be a safe and effective endovascular treatment for acutely ruptured intracranial aneurysm.

Treatment results of anterior choroidal artery aneurysms treated mostly with coil embolization: A single-center experience.

Anterior choroidal artery (AchA) aneurysms are usually small in diameter because of the size of the involved artery and are often wide-necked. Coil embolization of AchA aneurysm is thus challenging because of serious risks, such as thromboembolic occlusion of artery and perforation of aneurysm dome. Therefore, aneurysmal neck clipping remains widely performed despite a recent increase in the use of coil embolization for aneurysm treatment. We report the treatment results of AchA aneurysms mostly (92.3%) treated with coil embolization at our institute. The database and medical records of patients who underwent coil embolization for AchA aneurysms were retrospectively analyzed. The clinical and imaging results and procedure-related complications were investigated after coil embolization performed between January 2006 and March 2022 at our institute. In total, 96 AchA aneurysms comprising 65 unruptured and 31 ruptured aneurysms, including only 1 ruptured aneurysm (1.0%) re-embolized at postoperative day 192 because of coil compaction, were evaluated. After the initial coil embolization, complete occlusion was attained in 41, residual neck in 45, and residual aneurysm in 10 patients. Follow-up radiological studies after 6-174 months were performed for 80 aneurysms. Complete occlusion was noted in 57 patients, residual neck in 22, and residual aneurysm in 1. The dysarthria experienced by one (1.0%) patient was the only symptomatic procedure-related complication. After coil embolization, neither delayed new rupture nor re-rupture was observed. The results of this study demonstrate that coil embolization is a safe and effective treatment option for patients with AchA aneurysms.

Commentary: Coil Packing Density – Not Just for Cerebral Aneurysms

Coil packing density (CPD) has been recognized as a factor related to coil compaction or recanalization in the treatment of visceral and intracranial aneurysms ( 1 Yasumoto T. Osuga K. Yamamoto H. et al. Long-term outcomes of coil packing for visceral aneurysms: correlation between packing density and incidence of coil compaction or recanalization. J Vasc Interv Radiol. 2013; 24: 1798-1807 Abstract Full Text Full Text PDF PubMed Scopus (58) Google Scholar , 2 Kawanabe Y. Sadato A. Taki W. Hashimoto N. Endovascular occlusion of intracranial aneurysms with Guglielmi detachable coils: correlation between coil packing density and coil compaction. Acta Neurochir (Wien). 2001; 143: 451-455 Crossref PubMed Scopus (186) Google Scholar ). Simple coiling (SC), balloon remodeling (BR), and stent-assisted coiling are 3 commonly used techniques for percutaneously treating aneurysms. In the article by Kesim et al ( 3 Kesim Ç. Özcan Ü.C. Yildirim E. Effects of the cerebral aneurysm treatment method on coil packing density and its relationship with the ostium area. J Vasc Interv Radiol. 2022; 33: 631-638 Abstract Full Text Full Text PDF Scopus (1) Google Scholar ) titled “Effects of the Aneurysm Treatment Method on Coil Packing Density and Its Relationship with the Ostium Area,” the authors demonstrated that it is possible to achieve similar CPDs using these 3 coiling techniques while treating intracranial aneurysms and concluded that “in cerebral aneurysms treated with balloon- or stent-assisted coiling, the CPD value does not differ from that in aneurysms treated with simple coiling.” The authors noted that coiling technique is influenced by aneurysm neck size, with BR and stent-assisted coiling used for aneurysms with unfavorable neck morphology. Another possible conclusion is that for aneurysms with unfavorable neck morphology, BR and stent-assisted coiling make it possible to achieve CPDs similar to those achieved with SC in “simple” aneurysms. Effects of the Cerebral Aneurysm Treatment Method on Coil Packing Density and Its Relationship with the Ostium AreaJournal of Vascular and Interventional RadiologyVol. 33Issue 6PreviewTo test the following hypotheses: (a) balloon or stent assistance increases coil packing density (CPD) in the endovascular treatment of intracranial aneurysms, and (b) CPD correlates to ostium area (OA) and aneurysm volume (AV). Full-Text PDF

A Ruptured Blood Blister-Like Aneurysm that Experienced Regrowth with Coil Compaction Twice in a Month : Case Report

<p>Unlike other aneurysms, blood blister-like aneurysms(BBA) occur at non-branching sites, are commonly located at the dorsal wall of the supraclinoid internal carotid artery (ICA), and are suspected to arise from dissecting aneurysms. They are typically diagnosed after a bleed because of their small size and unusual site. Therefore, lesions exist after brain computed tomography or magnetic resonance imaging, but they are often not found. In the case of BBA, which have a high risk of recurrence, the treatment is difficult, and selecting the treatment method is also challenging. This paper describes the treatment of a BBA with internal trapping of the ICA that eventually recurred despite performing coil embolization twice.</p>

Surgical Clipping of Previously Coiled Recurrent Intracranial Aneurysms: A Single-Center Experience.

Objective: This study reviews our experiences in surgical clipping of previously coiled aneurysms, emphasizing on recurrence mechanism of intracranial aneurysms (IAs) and surgical techniques for different types of recurrent IAs.Method: We performed a retrospective study on 12 patients who underwent surgical clipping of aneurysms following endovascular treatment between January 2010 and October 2020. The indications for surgery, surgical techniques, and clinical outcomes were analyzed.Result: Twelve patients with previously coiled IAs were treated with clipping in this study, including nine females and three males. The reasons for the patients having clipping were as follows: early surgery (treatment failure in two patients, postoperative early rebleeding in one patient, and intraprocedural aneurysm rupture during embolization in one patient) and late surgery (aneurysm recurrence in five patients, SAH in one, mass effect in one, and aneurysm regrowth in one). All aneurysms were clipped directly, and coil removal was performed in four patients. One patient died (surgical mortality, 8.3%), 1 patient (8.3%) experienced permanent neurological morbidity, and the remaining 10 patients (83.4%) had good outcomes. Based on our clinical data and previous studies, we classified the recurrence mechanism of IAs into coil compaction, regrowth, coil migration, and coil loosening. Then, we elaborated the specific surgical planning and timing of surgery depending on the recurrence type of IAs.Conclusion: Surgical clipping can be a safe and effective treatment strategy for the management of recurrent coiled IAs, with acceptable morbidity and mortality in properly selected cases. Our classification of recurrent coiled aneurysms into four types helps to assess the optimal surgical approach and the associated risks in managing them.

Hemodynamic and Morphologic Factors Related to Coil Compaction in Basilar Artery Tip Aneurysms

Coil compaction is directly related to the degree of cerebral aneurysmal recanalization. The degree of recanalization (DoR) was quantified by measuring the volume vacated by coil deformation. The purpose of this study was to clarify the hemodynamic and morphologic factors associated with coil compaction. Computational fluid dynamics simulations were performed on 28 middle-size (5-10 mm) unruptured basilar artery tip aneurysms. The DoR was measured by comparing the coil mass shape obtained from three-dimensional digital subtraction angiography data immediately after coil embolization and again within 1-2 years of follow-up. Deployed coils were modeled using a virtual coiling technique for computational fluid dynamics simulations. Hemodynamic and morphologic factors to predict the DoR were derived using multiple linear regression. Aneurysmal neck area, the maximum pressure generated on the neck surface after coil embolization, and the high-pressure position on the neck surface predicted DoR with statistic significance (P < 0.001, P < 0.001, P= 0.004, respectively). The DoR tended to increase when the neck areawas large, the pressure generated on the coils was high, and the high-pressure position was close to the center of the neck surface. The volume embolization ratio was not statistically relevant for the DoR in the cases of this study. Coil compaction occurs in cerebral aneurysms with a wide neck, high pressure generated on the coils, and high pressure in the center of the neck surface. Establishing the DoR can contribute to the prediction of recanalization after coil embolization.

Experimental Study of Coil Compaction: Impact of Pulsatile Stress.

Coil compaction after aneurysm embolization is one of the major issues associated with aneurysm recurrence. On the presumption that pulsatile stress to the aneurysm is responsible for coil compaction, we developed an experimental model in vitro to visualize the mechanical stresses exerted by blood pressure and pulse and their relation to coil compaction. A closed-type non-circulation system was developed by installing a syringe that generated pressure at one end of a tube, along with a spherical aneurysm made of silicone and a pressure sensor in the bifurcated end. We installed a fixed-pressure model under a steady pressure of 300 mmHg while the pressure-fluctuation model simulated the pressure variations using a plunger (in a syringe) by using a motor that applied pulsatile stress in the range of 50 mmHg for a 10-ms cycle. We devised four types of aneurysms with different depths and the same coil length. After coil packing, the aneurysms were observed for 3 days (the observation period in the pressure-fluctuation model corresponded to approximately 300 days in real time). The distance from the datum point to the observable coil loops was determined as the initial position, and the temporal change in the distance from that position was measured. In the fixed-pressure model, the average distance of coil movement was very small (less than ±0.1 mm). In the pressure-fluctuation model, the movement of coils was observed to be significant for the two longest depths (0.11 and 0.14 mm). The maximal dynamic change in coil movement was observed on the second day. The range of movement was observed to decrease thereafter. Our experimental study enabled the observation of coil movement within a short duration. It examined coil compaction by applying pulsed pressure to the coils at high speeds. Consequently, a shift of the coil loops inside the incompletely occluded aneurysms was detected on applying a pulsed pressure.

The Fate of Partially Thrombosed Intracranial Aneurysms Treated with Endovascular Intervention.

ObjectiveThe fate of partially thrombosed intracranial aneurysms (PTIAs) is not well known after endovascular treatment. The authors aimed to analyze the treatment outcomes of PTIAs. MethodsWe retrospectively reviewed the medical records of 27 PTIAs treated with endovascular intervention between January 1999 and March 2018. Twenty-one aneurysms were treated with intraluminal embolization (ILE), and six were treated with parent artery occlusion (PAO) with or without bypass surgery. Radiological results, clinical outcomes and risk factors for major recurrence were assessed. ResultsThe initial clinical status was similar in both groups; however, the last status was better in the ILE group than in the PAO group (p=0.049). Neurological deterioration resulted from mass effect in one case and rupture in one after ILE, and mass effect in two and perforator infarction in one after PAO. Twenty cases (94.2%) in the ILE group initially achieved complete occlusion or residual neck status. However, 13 cases (61.9%) showed major recurrence, the major causes of which included coil migration or compaction. Seven cases (33.3%) ultimately achieved residual sac status after repeat treatment. In the PAO group, all initially showed complete occlusion or a residual neck, and just one case ultimately had a residual sac. Two cases showed major recurrence, the cause of which was incomplete PAO. Aneurysm wall calcification was the only significantly protective factor against major recurrence (odds ratio, 36.12; 95% confidence interval, 1.85 to 705.18; p=0.018). ConclusionComplete PAO of PTIAs is the best option if treatment-related complications can be minimized. Simple fluoroscopy is a useful imaging modality because of the recurrence pattern.

Placement of a Pipeline Embolization Device: 2-Dimensional Operative Video.

Flow diversion has been a game-changer in the treatment of wide-neck large and giant cavernous and supraclinoid internal carotid artery (ICA) aneurysms as well as large vertebral artery aneurysms. Prior to their existence, carotid sacrifice or clipping with or without external to internal carotid artery bypass was the mainstay of treatment. Prior to flow diversion, endovascular coil embolization was often not effective as a stand-alone treatment because of the fact that many of these aneurysms present with symptoms created by mass effect on the cavernous sinus cranial nerves by the aneurysm. Packing the aneurysm with coils did nothing to alleviate the mass effect and did not prevent flow from entering the aneurysm. The continued flow causes coil compaction and aneurysm enlargement. Flow diversion addressed both these issues by diverting flow from the aneurysm while allowing the aneurysm to slowly thrombose and shrink. The video is a step-by-step account of this procedure in a 72-yr-old male with a large recurrence of a previously coiled cavernous ICA aneurysm. The procedure was performed following informed consent.

Endovascular Retreatment of Previously Ruptured Coiled Cerebral Aneurysm Remnants Significantly Reduces Rebleed Rate

Treatment of ruptured cerebral aneurysms by endovascular coiling is associated with a better neurologic outcome when compared with neurosurgical clipping but has a higher risk for target aneurysm rebleeding after treatment. We hypothesize that aggressive retreatment of coiled aneurysms will lead to fewer recurrent hemorrhages as compared with historical values of 2.3%-3.0%. All first-time Guglielmi detachable coil-embolized cerebral aneurysms were retrospectively reviewed at a single institution from 2004 to 2015. Aneurysm retreatment after first-time embolization was recorded as well as time to retreatment. Retreatment at our institution is routinely performed for incomplete coiling with etiologies including incomplete initial coiling, coil compaction, and aneurysmal dilatation. Aneurysm rerupture was treated with additional coiling. Kaplan-Meier survival analysis was performed to evaluate embolization durability. There were 214 aneurysms that met inclusion criteria. Mean (standard deviation) follow-up was 2.74 (2.24) years. Aneurysms that were patent or recanalized were retreated. Mean (standard deviation) time to retreatment was 9 (9) months. Overall, 46 (21.5%) aneurysms required retreatment. Retreatment was performed for coil compaction/remnant growth, recanalization, persistent remnant, and rebleed. Two (0.9%) patients had recurrent aneurysm hemorrhage and both were treated with additional coil embolization. There were no new long-term neurologic deficits caused by aneurysm retreatment. Aggressive retreatment of previously ruptured, coiled cerebral aneurysms for persistent aneurysm patency reduces the recurrent hemorrhage risk to that historically seen in neurosurgically clipped aneurysms with minimal additional morbidity. This study validates a large body of literature demonstrating the significance of post-treatment aneurysm remnants and their association with recurrent hemorrhage.

Microsurgical treatment for the recurrent cerebral aneurysm initially treated using coil embolization.

ObjectiveMicrosurgical treatment could be a good alternative for the treatment of recurrent cerebral aneurysm after coil embolization. The purpose of this study was to present our experience of microsurgical treatment for recurrent cerebral aneurysm previously treated using coil embolization.MethodsFrom June 2012 to May 2019, 34 patients consecutively received microsurgical treatment for a recurrent cerebral aneurysm previously treated using coil embolization after it ruptured.ResultsOf the 34 patients with aneurysm, 33 had the aneurysm located in the anterior circulation. The most common location was the anterior communicating artery (13 cases). Immediate radiologic outcome at coil embolization was completed (n=6), residual neck (n=26), and residual sac (n=2). The reason for microsurgical treatment included rebleeding (n=12), persistent residual sac (n=1), and recurrence on follow-up study (n=21). Rebleeding occurred within 10 days after coil embolization in 10 cases, and the other 2 were due to regrowth. In the 20 recurred and saccular aneurysms, coil compaction was present in 11 aneurysms and regrowth in 9 aneurysms. Simple neck clipping (n=29) and clipping with coil mass extraction (n=3) was possible in the saccular aneurysms. The blood blister like aneurysm (n=2) were treated using bypass and endovascular internal carotid artery trapping. In the follow-up study group after microsurgical treatment there were no severe complications due to the treatment. Age, cause of retreatment, and modified Rankin Scale before microsurgery were associated with good outcome (p<0.001).ConclusionsMicrosurgical treatment may be a viable and effective option for treating recurrent aneurysms previously treated by endovascular techniques.

Assessing the Hemodynamics in Residual Cavities of Intracranial Aneurysm after Coil Embolization with Combined Computational Flow Dynamics and Silent Magnetic Resonance Angiography

Background and PurposeMetal artifacts limit computational fluid dynamics analysis after coil embolization. Silent magnetic resonance angiography reduces metal artifacts and improves visualization of the residual cavity of coil-embolized aneurysms. This study investigated the flow dynamics of the residual cavity after coil embolization using silent magnetic resonance angiography and computational fluid dynamics to elucidate the hemodynamic characteristics of recanalization. MethodsTwenty internal carotid-posterior communicating aneurysm cases treated with coil embolization and without stent assistance were followed up (mean±standard deviation, 13.0±6.1 months) and assessed using silent magnetic resonance angiography. The hemodynamic characteristics of the residual cavities in both types of aneurysms were compared between neck remnants, which persisted for >12 months (NR group), and those treated with coil compaction-induced body filling (BF group). Computational fluid dynamics analysis of each aneurysm was performed using morphological data obtained from silent magnetic resonance angiography. Pressure, pressure difference, normalized wall shear stress, and flow velocity were measured. ResultsThe residual cavity was well-visualized using silent magnetic resonance angiography and compared with those imaged using conventional time-of-flight magnetic resonance angiography, and eight internal carotid-posterior communicating aneurysms with neck remnants and body filling were investigated. The maximum pressure area was localized to the aneurysm wall in the NR group (n=4) and to sides of the coil surface in the BF group (n=4). No significant differences were observed for each hemodynamic parameter. ConclusionsCombination of silent magnetic resonance angiography and computational fluid dynamics helps to understand the hemodynamic characteristics of residual cavity in coil- embolized aneurysms. The flow-impingement zone at the coil surface (maximum pressure area) may influence the risk for future coil compaction.

Intra-aneurysmal embolization of cellulose porous beads to regenerate vessel wall: an experimental study.

Although the treatment of intracranial cerebral aneurysms with detachable coils is now widely accepted, the problem of coil compaction and recanalization remains unsolved. If the vessel wall can be regenerated at the neck orifice of an aneurysm, thereby reducing the blood flow into the aneurysm, the recurrence rate of the aneurysm would decrease. Accordingly, we aimed to insert cellulose porous beads (CPBs) into rat models of external carotid artery (ECA) aneurysm and study their efficacy in promoting vessel wall regeneration. Using a rat aneurysm model, we examined the tissue response to CPBs that were inserted into the ligated ECA sac of rats. The sacs were removed on days 14, 42, 84, and 180 after insertion and subjected to conventional and immunohistochemical examination. We evaluated the tissue response in the ECA sacs and observed the vessel wall regeneration progress. At the neck orifice of the aneurysm in which the CPB was inserted, a layer of regenerating α-smooth muscle actin-positive spindle cells was observed on day 14. The regenerative cell layer gradually thickened until day 42 and, thereafter, the thickness remained unchanged until day 180. A monolayer of factor VIII-positive cells also appeared at the neck orifice on day 14 and covered the entire orifice until day 180. The CPBs were stably localized in the sac without degradation or signs of inflammation. CPBs may be promising as embolic materials that can induce stable vessel wall regeneration at the neck orifice of an aneurysm without surrounding inflammatory reactions.

Abstract WP131: Is 3 Years Adequate for Tracking Completely Occluded Coiled Aneurysms?

Objective: To ascertain the long-term durability of coiled aneurysms completely occluded at 36 months during follow-up given the potential for delayed recanalization. Methods: As a retrospective review, we examined 299 patients with 339 aneurysms, all completely occluded at 36 months in follow-up images obtained between 2011 and 2013. Medical records and radiologic data acquired during extended monitoring (mean, 74.3±22.5 months) were retrieved, analyzing incidence (including average annual risk) and risk factors of delayed recanalization. Results: A total of five coiled aneurysms (1.5%) occluded completely at 36 months showed recanalization (0.46 % per aneurysm-year) during continued long-term surveillance (1081.9 aneurysm-years), two surfacing within 60 months and three developing thereafter. Four showed minor recanalization, with only one instance of major recanalization. The latter involved posterior communicating artery as an apparent de novo lesion, arising at the neck of a firmly coiled sac, and was unrelated to coil compaction or growth. Additional embolization was undertaken. In multivariate analysis, second embolization for recurred aneurysm (HR=22.088, p=0.003) independently correlated with delayed recanalization. Conclusion: Almost all coiled aneurysms (98.5%) showing complete occlusion at 36 months post-embolization proved to be stable in extended observation. Therefore, it is reasonable to suspend imaging surveillance of coiled aneurysms after 3 years in the absence of demonstrable recanalization. However, recurrent aneurysms were predisposed to delayed recanalization.

Cerebral aneurysms treated with low-profile visualized intraluminal support device (LVIS Jr) Y-stent constructs: Technical experience with a single microcatheter technique.

The LVIS Jr device holds a number of advantages but poses unique technical challenges compared to such, especially, complex multistent constructs. We report our experience with the technical feasibility and early to mid-term outcomes of Y-stent-assisted coiling with the LVIS Jr using a simple, single microcatheter technique. Using a departmental database, we retrospectively reviewed a single surgeon's experience with Y-stent-assisted coiling with LVIS Jr over a three-year period. Eighteen aneurysms in 17 patients were treated over this period. We assessed the technical success of the procedures, the initial and follow-up radiographic success with the modified Raymond-Roy occlusion score and follow-up clinical outcome with the modified Rankin scale. All stents were successfully deployed, and 17 of 18 aneurysms were successfully coiled at the initial treatment for a technical success rate of 94.4%. Of the 17 aneurysms with follow-up imaging, all were modified Raymond-Roy grade 1 or 2. One aneurysm required retreatment for coil compaction and a growing neck. There were two immediate postprocedure symptomatic strokes and one delayed stroke related to antiplatelet non-compliance. The two immediate symptomatic strokes recovered to neurological baseline with no residual deficits by the time of discharge. The long-term morbidity rate was 5.5%. The mortality rate was 0%. All patients had a modified Rankin Scale ≤ 2 at most recent follow-up. Treatment with LVIS Jr Y-stent constructs via a single microcatheter technique is technically feasible with good radiographic and clinical outcomes.

Is 3 years adequate for tracking completely occluded coiled aneurysms?

The authors conducted a study to ascertain the long-term durability of coiled aneurysms completely occluded at 36 months' follow-up given the potential for delayed recanalization. In this retrospective review, the authors examined 299 patients with 339 aneurysms, all shown to be completely occluded at 36 months on follow-up images obtained between 2011 and 2013. Medical records and radiological data acquired during the extended monitoring period (mean 74.3 ± 22.5 months) were retrieved, and the authors analyzed the incidence of (including mean annual risk) and risk factors for delayed recanalization. A total of 5 coiled aneurysms (1.5%) occluded completely at 36 months showed recanalization (0.46% per aneurysm-year) during the long-term surveillance period (1081.9 aneurysm-years), 2 surfacing within 60 months and 3 developing thereafter. Four showed minor recanalization, with only one instance of major recanalization. The latter involved the posterior communicating artery as an apparent de novo lesion, arising at the neck of a firmly coiled sac, and was unrelated to coil compaction or growth. Additional embolization was undertaken. In a multivariate analysis, a second embolization for a recurrent aneurysm (HR = 22.088, p = 0.003) independently correlated with delayed recanalization. Almost all coiled aneurysms (98.5%) showing complete occlusion at 36 months postembolization proved to be stable during extended observation. However, recurrent aneurysms were predisposed to delayed recanalization. Given the low probability yet seriousness of delayed recanalization and the possibility of de novo aneurysm formation, careful monitoring may be still considered in this setting but at less frequent intervals beyond 36 months.

A Retrospective Analysis of Treatment Outcomes of 40 Incidental Cavernous Carotid Aneurysms

The management of cavernous carotid aneurysms (CCAs) poses a significant dilemma to the treating surgeon. Asymptomatic CCAs usually are managed conservatively with clinical and radiologic follow-up. Large size, intradural extension, sphenoid bone erosion, and increasing size on follow-up are usual indications for treating asymptomatic CCAs. However, there are no clear-cut guidelines in literature. We share our experience of 40 asymptomatic CCAs treated by endovascular and surgical methods. All the asymptomatic CCAs treated between January 2014 and December 2018 were analyzed retrospectively. Patient demographics, aneurysm characteristics, postprocedural complications, and clinical and radiologic follow-up data were obtained from records. Outcome was evaluated in terms of aneurysm obliteration and maintained cerebral perfusion, postoperative complications, recurrence, and clinically significant complications during follow-up. Endovascular coiling, balloon-assisted coiling, and stent-assisted coiling were performed in 27 (75%), 5 (13.9%), and 4 (11.1%), respectively. Raymond-Roy occlusion classification grade I occlusion was achieved in 88.9% of cases. No immediate or delayed complications were noted. Coil compaction was seen in 4 (11.1%) patients. In the surgery group, all patient underwent high-flow bypass with radial artery graft. Aneurysm exclusion with good graft patency was achieved in all 4 cases without any permanent morbidity or mortality. The current study demonstrates excellent outcomes of asymptomatic CCAs after treatment. In view of the technical advancements of both surgical and endovascular methods, consideration for treatment should be given to asymptomatic CCAs. Each aneurysm should be individually assessed by experts for choosing the best endovascular or surgical treatment option.

A Study of Cryostructuring of Polymer Systems. 51. The Combined Influence of Porous Cellulose-Containing Dispersed Fillers and Salting-Out Electrolytes on the Physicochemical Properties of Composite Poly(vinyl alcohol) Cryogels

Composite poly(vinyl alcohol) (PVA) cryogels comprising dispersed porous cellulose-containing fillers (microcrystalline cellulose, wood sawdust) and salting-out electrolytes (Na2SO4, NaF) have been prepared by freezing at –20°C, incubation in the frozen state for 12 h, and defrosting at a rate of 0.03°C/min. The influence of the chemical nature and concentration of the soluble additives and fillers on the rheological behavior of initial suspensions, as well as the morphology of macropores and physicochemical and thermophysical properties of corresponding composite cryogels, has been studied. Viscometric studies have shown that, because of the salting-out action of the electrolytes, the viscosity of PVA solutions decreases due to the compaction of macromolecular coils. However, in the case of filler suspensions, the viscosity increases owing to the enhancement of the adhesion interactions between the discrete and continuous phases, thereby affecting the rigidity and heat endurance of filled cryogels resulting from the freezing–defrosting of such suspensions. The most pronounced increase in the compression elasticity modulus and heat endurance of the composites takes place upon the combined incorporation of a porous filler and a salting-out electrolyte into the cryogel matrix. The microstructure of both unfilled and filled cryogels has been studied by scanning electron microscopy. Substantial changes have been revealed in the macroporous morphology of these objects upon the incorporation of a porous dispersed cellulose-containing filler or a salting-out electrolyte separately and, especially, upon their combined incorporation into the matrix of the PVA cryogel.

Transclival clipping for giant vertebral artery aneurysm: A case report

Abstract Background Endovascular treatment often achieves complete obliteration of VA giant aneurysm; however, retreatment may be required because of late recanalization. We report a case of giant VA aneurysm that showed regrowth after endovascular treatment and was treated with VA clipping using the endoscopic endonasal transclival approach. Case description A 47-year-old man with chief complaint of ataxia underwent endovascular treatment of giant VA aneurysm. One year later, he needed additional treatment to regrowth of the aneurysm. We were not able to accomplish aneurysmectomy via the transcondylar fossa approach because of difficulty in achieving hemostasis and ended with partial thrombectomy. Digital subtraction angiography (DSA) performed after 4 months revealed coil compaction and distal flow due to recanalization. Right VA elongation and position of anterior spinal artery (ASA), these factors made possible for us to perform transclival approach to VA. Despite the limited indications for its use, endonasal endoscopic transclival clipping may be effective in limited anatomical cases. Conclusion We report the use of endonasal endoscopic transclival clipping for giant VA aneurysm. This endonasal endoscopic treatment may be an optional alternative in only limited cases depending upon the anatomical location of the lesion because of limitations of vascular control and the inability to visualize the field in the presence of major bleeding. For treatment of progressive giant VA aneurysm, it is very important to avoid optimistic strategy for giant VA aneurysm initially.

Selective occlusion of splenic artery aneurysms with the coil packing technique: the impact of packing density on aneurysm reperfusion correlated between contrast-enhanced MR angiography and digital subtraction angiography.

The aim was to evaluate the relationship between coil packing densities after splenic artery aneurysm (SAA) treatment using detachable microcoils and rates of SAA reperfusion and to suggest a post-treatment surveillance protocol using contrast-enhanced MRA. Evaluated were 16 patients (4 men; mean age 46.7), who underwent true SAA embolization using detachable microcoils (Concerto, Medtronic). SAAs were treated by selective coil packing (CP) or stent-assisted coil exclusion (SAC). Contrast-enhanced magnetic resonance angiography (CE-MRA) and digital subtraction angiography (DSA) were performed at 3months post-procedure and correlated. Primary CP was used in 13 patients, while SAC was used in three patients. On follow-up, complete aneurysm occlusion was seen in seven patients (43.8%). Sac reperfusion occurred in nine patients (56.2%) and was demonstrated in all CE-MRA and six DSA studies. Mean aneurysm packing density was 20.10 ± 8.05% for the CP group and 32.90 ± 11.95% for the SAC group (p = 0.038). There was a significant difference in the incidence of aneurysm sac reperfusion on CE-MRA study between CP and SAC (9 vs. 0). No sac reperfusion was seen in aneurysms with packing densities ≥ 29%, irrespective of either embolization method. Favorable midterm results for coil packing of SAAs seem to depend on the coil packing density with a coil volume approximately a quarter of the aneurysm volume being most effective. Follow-up should involve the use of CE-MRA as this modality has been shown to be superior over DSA in detecting aneurysm reperfusion and coil compaction. Level IV, therapeutic study.