Aneurysm Regrowth Research Articles

Efficacy of Endovascular Glue Embolization in Treating Ruptured Intracranial Mycotic Aneurysms: A Single Center Experience.

Intracranial mycotic aneurysms (IMAs), rare and often life-threatening, result from arterial wall infections typically caused by bacteria such as Staphylococcus and Streptococcus. The standard treatment for ruptured aneurysms is not well-defined and often individualized. This study investigates the efficacy of endovascular glue embolization in managing ruptured IMAs, based on our center's experience. A retrospective analysis was conducted for ruptured IMAs treated with glue embolization between January 2016 and December 2023. The procedure involved aneurysm sac and parent vessel occlusion with glue delivery. Data included patient demographics, clinical presentations, and neuroimaging. Clinical outcomes were assessed using the modified Rankin scale (mRS) at 3 months, and angiographic follow-up was conducted at 6 months. The study included 28 patients, predominantly male (64.3%), with a mean age of 48 years. Headache was the primary symptom in 92.9% of cases, and positive blood/cerebro spinal fluid cultures were found in 82.14% of cases. All aneurysms were located in the distal circulation, primarily in the anterior circulation system. Glue embolization was successfully performed in all cases, achieving complete aneurysm sac and parent vessel obliteration. Follow-up at 3 months indicated mRS scores of 0 or 1 in 96.5% of cases. Six-month angiographic follow-up showed no aneurysm regrowth or new formations. Endovascular glue embolization demonstrated high efficacy and safety in treating ruptured IMAs, with a 100% obliteration rate and favorable clinical outcomes in this single-center experience. Despite limitations such as its retrospective design and small sample size, the study supports glue embolization as a viable, less invasive alternative to traditional surgery. Further comparative studies are needed to confirm these findings and refine treatment approaches.

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.

Computer-Assisted Microcatheter Shaping for Intracranial Aneurysm Embolization.

This study investigates the accuracy, stability, and safety of computer-assisted microcatheter shaping for intracranial aneurysm coiling. Using the solid model, a microcatheter was shaped using computer-assisted techniques or manually to investigate the accuracy and delivery of microcatheter-shaping techniques in aneurysm embolization. Then, forty-eight patients were randomly assigned to the computer-assisted microcatheter-shaping (CAMS) group or the manual microcatheter-shaping (MMS) group, and the accuracy, stability, and safety of microcatheter in the patients were compared between the CAMS and MMS groups. The speed of the successful microcatheter position was significantly faster in the CAMS group than in the MMS group (114.4 ± 23.99 s vs. 201.9 ± 24.54 s, p = 0.015) in vitro. In particular for inexperienced operators, the speed of the microcatheter position with the assistance of computer software is much faster than manual microcatheter shaping (93.6 ± 29.23 s vs. 228.9 ± 31.27 s, p = 0.005). In vivo, the time of the microcatheter position in the MMS group was significantly longer than that in the CAMS group (5.16 ± 0.46 min vs. 2.48 ± 0.32 min, p = 0.0001). However, the mRS score at discharge, the 6-month follow-up, and aneurysm regrowth at the 6-month follow-up were all similar between the groups. Computer-assisted microcatheter shaping is a novel and safe method for microcatheter shaping that introduces higher accuracy in microcatheter shaping during the treatment of intracranial aneurysms. Endovascular coiling of intracranial aneurysms can be truly revolutionized through computer assistance, which could improve the endovascular treatment of aneurysms.

New aneurysm formation and regrowth associated with rebleeding of residual pediatric ruptured arteriovenous malformation: patient series.

If complete obliteration of ruptured pediatric arteriovenous malformation (AVM) cannot be achieved, the appropriate follow-up duration and predictors of rebleeding remain unknown. Pediatric patients with ruptured AVMs admitted to the authors' hospital within the past 30 years were evaluated. Rebleeding was confirmed in two patients. The first patient was a 5-year-old boy who experienced right thalamic hemorrhage. AVM was found in the bilateral thalamus and treated with stereotactic radiosurgery (SRS). New aneurysm formation and residual AVM regrowth were confirmed 21 years after the SRS. Eight months later, rebleeding occurred. The second patient was a 5-year-old boy who underwent removal of a left cerebellar hemorrhage and AVM. The residual AVM was treated with SRS. Residual AVM regrowth was detected at 6 years 7 months after SRS. Five months later, new aneurysm formation was confirmed. Two additional days later, rebleeding occurred. New aneurysm formation and residual AVM regrowth may predict rebleeding and can occur >20 years after the initial rupture and treatment. If AVM obliteration is not achieved, long-term follow-up is needed, even in adulthood, with attention to new aneurysm formation and residual AVM regrowth. Further treatment is recommended if these findings are confirmed.

Characteristics of Unruptured Intracranial Aneurysms with Delayed Rupture Following Coil Embolization: Case Series and Review of the Literature.

Long-term clinical outcomes including delayed rupture of unruptured intracranial aneurysms (UIAs) after coil embolization (CE) remain unclear. The purpose of this study was to evaluate the precise timing of re-treatment for recanalized UIAs before rupture. From February 2012 to June 2020, a total of 197 patients with 207 UIAs underwent CE in our institution and were followed up for more than 6 months. The follow-up period, as well as morphological changes from treatment to recanalization, regrowth, and rupture, was retrospectively analyzed. Delayed rupture was defined as a rupture that occurred more than 1 month after CE. The average length of follow-up was 48.7 months. Three of 207 UIAs (1.45%) ruptured after CE. The aneurysm locations were the middle cerebral artery (MCA), anterior communicating artery (AcomA), and internal carotid artery-posterior communicating artery (ICA-Pcomm). The annual rupture rate after CE was 0.36%. Immediately after the first CE, treated aneurysms were graded according to the Modified Raymond-Roy Classification with class II for MCA aneurysms and class IIIb for AcomA and ICA-Pcomm aneurysms. The ICA-Pcomm aneurysm was treated with two additional CEs and was finally graded as class I. In all cases, DSA or MRA before aneurysm rupture showed recanalization and regrowth of aneurysms. The average periods from final embolization to regrowth and from regrowth to rupture were 54.3 months (±16.8) and 2.3 months (±0.9), respectively. UIAs with recanalization and regrowth after CE should undergo re-treatment as early as possible.

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.

Paraclinoid Segment Aneurysms of the Internal Carotid Artery: Surgical Clipping.

Paraclinoid segment aneurysms arise from the internal carotid artery (ICA) between the distal dural ring and the origin of the posterior communicating (PComm) artery. This pictorial study presents videos showing clipping of paraclinoid segment aneurysms. The various subtypes of these aneurysms, the nuances in the technique of clinoidectomy, and methods of proximal control are presented. Cavernous ICA is designated as C4, clinoidal segment (between the proximal and distal dural rings) as C5, and supraclinoid segment (between the distal dural ring up to the PComm artery as C6 segment. The techniques used for clipping various aneurysms are based upon their subtypes and location. In the first case, in a giant superior hypophyseal artery aneurysm directed toward the suprasellar region, an intradural clinoidectomy helped in accessing the neck of the aneurysm encroaching into the clinoidal segment of ICA. In the second case, concurrent bilateral "kissing" paraclinoid segment aneurysms were clipped using a unilateral approach. In the third case, clipping of a dissecting paraclinoid segment aneurysm is demonstrated. Surgery still represents the most definitive form of treatment. It may also be used to evacuate an intracerebral hematoma, with an extremely tortuous proximal vessel or in an aneurysm with complex anatomy, with blister aneurysms, or following aneurysm regrowth following a failed endovascular procedure. Assessing the three-dimensional anatomy of various segments of ICA is an important step.

The value of long-term angiographic follow-up following Pipeline embolization of intracranial aneurysms

BackgroundFlow diversion of intracranial aneurysms with the Pipeline Embolization Device (PED) is commonly performed, but the value of long-term angiographic follow-up has not been rigorously evaluated. Here we examine the...

Frequency and risk factors for postoperative aneurysm residual after microsurgical clipping

ObjectiveAneurysm residuals after clipping are a well-known problem, but the course of aneurysm remnants in follow-up is not well studied. No standards or follow-up guidelines exist for treatment of aneurysm remnants. The aim of this study was to evaluate the risk factors for postoperative aneurysm remnants and their changes during follow-up.MethodsWe performed a retrospective analysis of 666 aneurysms treated via clipping in our hospital from 2006 to 2016. Postoperative and follow-up angiographic data were analyzed for aneurysm remnants and regrowth. Clinical parameters and aneurysm-specific characteristics were correlated with radiological results.ResultsThe frequency of aneurysm residuals was 12% (78/666). Aneurysms located in the middle cerebral artery (p = 0.02) showed a significantly lower risk for incomplete aneurysm occlusion. Larger aneurysms with a diameter of 11–25 mm (p = 0.005) showed a significantly higher risk for incomplete aneurysm occlusion. Five patients underwent re-clipping during the same hospital stay. Remnants were stratified based on morphological characteristics into “dog ears” (n = 60) and “broad based” (n = 13). The majority of the “dog ears” stayed stable, decreased in size, or vanished during follow-up. Broad-based remnants showed a higher risk of regrowth.ConclusionsA middle cerebral artery location seems to lower the risk for the incomplete clip occlusion of an aneurysm. Greater aneurysm size (11–25 mm) is associated with a postoperative aneurysm remnant. The majority of “dog-ear” remnants appear to remain stable during follow-up. In these cases, unnecessarily frequent angiographic checks could be avoided. By contrast, broad-based residuals show a higher risk of regrowth that requires close imaging controls if retreatment cannot be performed immediately.

Early major recurrence of cerebral aneurysms after satisfactory initial coiling.

Early major recurrence (EMR) of cerebral aneurysms treated by coiling has not been investigated. The purpose of this study is to characterize the frequency and risk factors of this phenomenon. A retrospective review was performed of consecutive patients who presented with ruptured and unruptured cerebral aneurysms and underwent coiling from July 2009 to June 2019 at a university hospital. We defined EMR as recurrence of the aneurysm greater than its initial size within the first 6 months of an initial satisfactory coil embolization. Patient demographics, clinical information, aneurysm characteristics, angiographic and technical details were reviewed. From July 2009 to June 2019, 338 aneurysms (190 unruptured aneurysms and 148 ruptured cerebral aneurysms) underwent coiling and satisfied our study criteria. Among these patients, 23 patients (19 ruptured and 4 unruptured aneurysms) were found to have recurrent aneurysm. Of those, 4 were found to have early major aneurysm regrowth occurring within 6 months after coiling (1.2%). The detection of the EMR was as early as 4 weeks and as late as 20 weeks after the initial coil embolization. The average detection time was 10 ± 7.2 weeks (mean ± SD, range:4-20 weeks). In each case, the recurrent aneurysm cavity was more than twice the initial size of presentation. All aneurysms with major recurrence were ruptured with low aspect ratios (dome height to neck ratio) and involved a communicating segment. All patients underwent successful retreatment of the recurrent aneurysm with good outcome. Early major recurrence of treated aneurysms is a rare but important complication that harbors an impending risk of re-rupture. Early control angiography after endovascular coiling may be warranted for small ruptured aneurysms, even in cases in which the initial result seems technically satisfactory.

Black-blood vessel wall magnetic resonance imaging – A new imaging biomarker for regrowth of coiled saccular aneurysms?

BackgroundVessel wall imaging (VWI) of cerebral aneurysms is a new tool to risk stratify unruptured aneurysms. We hypothesized that the degree and pattern of aneurysm wall enhancement may predict the regrowth of these aneurysms. The aim of this study was to identify patient risk factors and VWI parameters associated with aneurysm regrowth. MethodsWe retrospectively reviewed 71 saccular aneurysms and 75 follow-up VWI studies in patients who underwent the coil embolization procedure for unruptured saccular aneurysm. The relationship between VWI enhancement and aneurysm regrowth was analyzed by Pearson’s chi-square test. Diagnostic performance of VWI enhancement in the diagnosis of regrowth aneurysm was determined to compare with digital subtraction angiography (DSA), and contrast-enhanced magnetic resonance angiography (CE-MRA) or time-of-flight MRA (TOF-MRA). Inter-rater agreement was measured by Cohen’s kappa coefficient. ResultsFourteen of 71 aneurysms (19.71%) were categorized into the aneurysm regrowth group, while aneurysm wall enhancement was found in 55 studies (73.33%). All wall enhancements were found in the aneurysm regrowth group, and no significant association was found between aneurysm regrowth and patient risk factors or VWI parameters. The diagnostic performance parameters of VWI relative to the DSA, and CE-MRA or TOF-MRA results were 100% sensitivity, 38.5% specificity, 30.4% positive predictive value, 100% negative predictive value, and 52% accuracy. ConclusionsWall enhancement of post-coil embolization of saccular aneurysm on VWI may be used as a screening imaging test to predict aneurysm regrowth, and may help to identify an unstable aneurysm, if the degree of enhancement increase or change of the pattern.

Cerebral Aneurysm Wall Stress After Coiling Depends on Morphology and Coil Packing Density.

Endovascular coil embolization is now widely used to treat cerebral aneurysms (CA) as an alternative to surgical clipping. It involves filling the aneurysmal sac with metallic coils to reduce flow, induce clotting, and promote the formation of a coil/thrombus mass which protects the aneurysm wall from hemodynamic forces and prevents rupture. However, a significant number of aneurysms are incompletely coiled leading to aneurysm regrowth and/or recanalization. Computational models of aneurysm coiling may provide important new insights into the effects of intrasaccular coil and thrombus on aneurysm wall stresses. Porcine blood and platinum coils were used to construct an in vitro coil thrombus mass (CTM) for mechanical testing. A uniaxial compression test was performed with whole blood clots and CTM, with coil packing densities (CPDs) of 10%, 20%, and 30% to obtain compressive stress/strain responses. A fourth-order polynomial mechanical response function was fit to the experimentally obtained stress/strain responses for each CPD in order to represent their mechanical properties for computational simulations. Patient-specific three-dimensional (3D) geometries of three aneurysms with simple geometry and four with complex geometry were reconstructed from digital subtraction angiography (DSA) images. The CPDs were digitally inserted in the aneurysm geometries and finite element modeling was used to determine transmural peak/mean wall stress (MWS) with and without coil packing. Reproducible stress/strain curves were obtained from compression testing of CTM and the polynomial mechanical response function was found to approximate the experimental stress/strain relationship obtained from mechanical testing to a high degree. An exponential increase in the CTM stiffness was observed with increasing CPD. Elevated wall stresses were found throughout the aneurysm dome, neck, and parent artery in simulations of the CAs with no filling. Complete, 100% filling of the aneurysms with whole blood clot and CPDs of 10%, 20%, and 30% significantly reduced MWS in simple and complex geometry aneurysms. Sequential increases in CPD resulted in significantly greater increases in MWS in simple but not complex geometry aneurysms. This study utilizes finite element analysis to demonstrate the reduction of transmural wall stress following coil embolization in patient-specific computational models of CAs. Our results provide a quantitative measure of the degree to which CPD impacts wall stress and suggest that complex aneurysmal geometries may be more resistant to coil embolization treatment. The computational modeling employed in this study serves as a first step in developing a tool to evaluate the patient-specific efficacy of coil embolization in treating CAs.

Coil Embolization in Patients with Recurrent Cerebral Aneurysms Who Previously Underwent Surgical Clipping.

Surgical revision of recurrent cerebral aneurysms is technically difficult. Therefore, coil embolization has been used as an alternative in these cases. The aim of this study was to evaluate the clinical and angiographic outcomes of coil embolization in patients with recurrent cerebral aneurysms after microsurgical clipping. Between May 1999 and February 2016, nineteen patients with 19 recurrent aneurysms who previously underwent surgical clipping were treated by coil embolization. Nine patients presented with subarachnoid hemorrhage (47.4%). The interval between surgical clipping and coil embolization was 143.5 ± 66.1 months (range, 43-276 months). Single- or double-catheter coil embolization was performed in 16 patients. A balloon (n = 1) and stents (n = 2) were used to assist the coil embolization in 3 patients. Immediate radiologic findings after coil embolization showed complete occlusion in 10 patients, a residual neck in 8 patients, and a residual sac in 1 patient. Procedure-related permanent morbidity occurred in 1 patient. The mean clinical follow-up was 58.3 ± 38.8 months. Poor clinical outcomes (modified Rankin Scale score = ≥3) at the end of the clinical follow-up were reported in 5 patients (26.3%). Angiographic follow-up was available for 12 patients (63.2%). Major recurrence was detected in 5 patients (41.7%), and a tendency for aneurysm regrowth rather than coil compaction was noted in all cases. In our series, coil embolization for recurrent aneurysms after surgical clipping was feasible but had a high recurrence rate and tended to result in aneurysm regrowth rather than coil compaction.

Effect of Local Coil Density on Blood Flow Stagnation in Densely Coiled Cerebral Aneurysms: A Computational Study Using a Cartesian Grid Method.

Aneurysm recurrence is the most critical concern following coil embolization of a cerebral aneurysm. Adequate packing density (PD) and coil uniformity are believed necessary to achieve sufficient flow stagnation, which decreases the risk of aneurysm recurrence. The effect of coil distribution on the extent of flow stagnation, however, especially in cases of dense packing (high PD), has received less attention. Thus, the cause of aneurysm recurrence despite dense packing is still an open question. The primary aim of this study is to evaluate the effect of local coil density on the extent of blood flow stagnation in densely coiled aneurysms. For this purpose, we developed a robust computational framework to determine blood flow using a Cartesian grid method, by which the complex fluid pathways in coiled aneurysms could be flexibly treated using an implicit function. This tool allowed us to conduct blood flow analyses in two patient-specific geometries with 50 coil distribution patterns in each aneurysm at clinically adequate PD. The results demonstrated that dense packing in the aneurysm may not necessarily block completely the inflow into the aneurysm and local flow that formed in the neck region, whose strength was inversely related to this local PD. This finding suggests that local coil density in the neck region still plays an important role in disturbing the remaining local flow, which possibly prevents thrombus formation in a whole aneurysm sac, increasing the risk of aneurysm regrowth and subsequent recurrence.

A coil placement technique to treat intracranial aneurysm with incorporated artery

BackgroundEndovascular coil embolization is an accepted treatment option for intracranial aneurysms. However, the coiling of aneurysms with an incorporated artery (IA) poses a high risk of IA occlusion. Here we report our experience of endovascular coil placement using a technique that avoids IA occlusion in aneurysms with IAs. MethodsOver a 6-year period, 185 patients harboring 206 intracranial aneurysms underwent endosaccular coiling. Forty-two of these patients with 45 aneurysms were treated by coil placement to avoid IAs occlusion. We assessed the anatomy of the aneurysms and IAs, technical feasibility of the procedure, and degree of aneurysm occlusion. Clinical and angiographic outcomes were assessed as well. ResultsAneurysms were located in the supra-clinoid intracranial internal carotid artery (n = 24), anterior cerebral artery (n = 6), middle cerebral artery (n = 7), and vertebrobasilar artery (n = 8). The IA was at the aneurysm neck in 34 patients, body in 10, and dome in 1. Immediate post-coiling angiogram showed preservation of blood flow through the IA in all aneurysms. Coil compaction with aneurysmal regrowth was found in 7 of 36 patients having follow-up conventional angiography. One patient had an IA territory infarction after embolization. All 42 patients were followed up (mean: 21 months) and showed no re-bleeding. ConclusionThis technique is effective and safe in managing intracranial aneurysms with IAs. Although aneurysmal recurrence may occur in some aneurysms because of insufficient coiling, this technique is simpler to perform and requires less skill than other techniques. It can be an alternative option for treating some selected intracranial aneurysms with IAs.

A Case of Ruptured Blood Blister-like Aneurysm Treated with Pipeline Embolization Device: Clinical Significance of Fetal-type Posterior Communicating Artery.

Blood-blister like aneurysms (BBAs) are challenging lesions because of their wide fragile neck. Flow-diverting stents (FDSs), such as the Pipeline Embolization Device (PED), have been applied to treat BBAs less amenable to more established techniques of treatment. However, the use of FDSs, including the PED, in acute subarachnoid hemorrhage (SAH) still remains controversial. We report a case of aneurysm regrowth following PED application for a ruptured BBA that overlapped the origin of the dominant posterior communicating artery (PCoA), which was successfully treated after coil trapping of the origin of the fetal-type PCoA. And, we discuss the clinical significance of the fetal-type PCoA communicating with a BBA in terms of PED failure.

Multidisciplinary management for the treatment of proximal posterior inferior cerebellar artery aneurysms

Objectives: Aneurysms of the proximal posterior inferior cerebellar artery (PICA) are rare. The management of proximal PICA aneurysms is challenging with either surgical or endovascular treatment. We report our successful experience of treating PICA aneurysms with a multimodal approach.Methods: Of 2382 treated aneurysms, 22 aneurysms in 21 patients (male:female 8:13, mean age 48.9 years) were enrolled from March 1998 to December 2015. We treated the aneurysms with a multimodal approach and performed angiography to examine aneurysm regrowth at the 12 months follow-up. Clinical outcomes were evaluated based on the modified Rankin Score (mRS) at the time of discharge and 12 months postoperatively. The treatment modality was mainly dependent on the character of the aneurysms and the clinical presentation of the patients.Results: Microsurgery was performed in seven patients, which entailed proximal occlusion with distal revascularization in two and microsurgical clipping in five. Endovascular treatment was performed in 10 patients because of a serious medical condition, or vertebral artery (VA)/ or PICA tortuosity. Four were treated with coil embolization and six with stent or balloon-assisted coil embolization. Combined surgical and endovascular treatment was applied in four patients. They were treated with distal revascularization followed by occlusion with coils of the aneurysm-incorporated PICA. All patients achieved complete cure of the PICA aneurysms without complications except for one case of cerebrospinal fluid (CSF) leakage.Discussion: Endovascular and microvascular neurosurgeons should work closely in managing these challenging problems. Neurosurgeons should consider multimodal treatment in these cases including trapping after occipital artery (OA)-PICA bypass.

A Case of Aneurysm Regrowth Adjacent to the Neck after Sac Embolization of Renal Artery Aneurysm

A Case of Aneurysm Regrowth Adjacent to the Neck after Sac Embolization of Renal Artery Aneurysm

Successful Retreatment of Recurrent Intracranial Vertebral Artery Dissecting Aneurysms After Stent-Assisted Coil Embolization: A Self-Controlled Hemodynamic Analysis

Intracranial vertebral artery dissecting aneurysms (VADAs) tend to recur despite successful stent-assisted coil embolization (SACE). Hemodynamics is useful in evaluating aneurysmal formation, growth, and rupture. Our aim was to evaluate the hemodynamic patterns of the recurrence of VADA. Between September 2009 and November 2013, all consecutive patients with recurrent VADAs afterSACE in our institutions were enrolled. Recurrence was defined as recanalization and/or regrowth. We assessed the hemodynamic alterations in wall shear stress(WSS) and velocity after the initial SACE and subsequently after retreatment of the aneurysms that recurred. Five patients were included. After the initial treatment, 3 patients showed recanalization and 2 showed regrowth. In the 2 patients with regrowth, the 2 original aneurysms maintained complete occlusion; however, denovo aneurysm regrowth was confirmed near the previous site. Compared with 3 recanalized aneurysms, the completely occluded aneurysms showed high mean reductions in velocity and WSS after initial treatment (velocity, 77.6% vs. 57.7%; WSS, 74.2% vs. 52.4%); however, WSS remained high at the region near the previous lesion where the new aneurysm originated. After the second retreatment, there was no recurrence in any patient. Compared with the 3 aneurysms that recanalized, the 4aneurysms that maintained complete occlusion showed higher reductions in velocity (62.9%) and WSS (71.1%). Our series indicated that hemodynamics might have an important role in recurrence of VADAs. After endovascular treatment, sufficient hemodynamic reduction in aneurysm dome, orifice, and parent vessel may be one of the key factors for preventing recurrence in VADAs.

Open Surgery for Recurrent Intracranial Aneurysms: Techniques and Long-Term Outcomes

After occlusion of an aneurysm, a patient may experience aneurysm regrowth at the same site or develop de novo aneurysms. We present our experience in microsurgery of recurrent aneurysms with analysis of long-term results. The senior authors (R. T. and H. K.) performed recurrent aneurysm clipping on 44 patients at Teishinkai Hospital and Asahikawa Red Cross Hospital in Sapporo, Japan. Operative techniques included clipping only, clipping and protective bypass, trapping of aneurysm with bypass, proximal occlusion, and bypass. Postoperative outcome was analyzed retrospectively using the modified Rankin Scale. Our series included 10 men (23%) and 34 women (77%), with a mean patient age of 63 years (range, 7-82 years). Before primary treatment, 11 patients (25%) had a ruptured aneurysm, while 33 patients (75%) had an unruptured aneurysm. The mean follow-up time after primary surgery was 7.6 years (range, 0.8-25 years). At our department the treatment of recurrent aneurysm included the clipping in 19 patients (43%), clipping with bypass in 6 patients (14%), aneurysm trapping with bypass in 10 patients (23%), and proximal occlusion and bypass in 9 patients (20%). The mean follow-up time after surgical treatment of recurrent aneurysms stood at 3.5 years (range 0.1-9 years). Altogether, 37 patients (84%) experienced favorable outcomes at last follow-up examination (modified Rankin Scale scores 0 and 1). Microsurgery of recurrent aneurysms may be performed safely and effectively, as shown by our study, in which 84% of patients experienced favorable results.