Endovascular coil embolization of very small intracranial aneurysms

Surgical clipping and endovascular treatments for small or very small anterior communicating artery aneurysms: A comparative pooled analysis

INTRODUCTION

Small and very small anterior communicating artery (ACoA) aneurysms pose a complex challenge in neurosurgery and interventional neuroradiology due to their critical location and potential for severe consequences upon rupture. Surgical clipping has been a traditional approach, but it presents challenges requiring precision and expertise. Endovascular treatment has emerged as an alternative, offering minimally invasive techniques with potential advantages. This study aims to comprehensively compare outcomes and efficacy between surgical clipping and endovascular treatment for small or very small ACoA aneurysms.

OBJECTIVES

We aimed to perform a meta-analysis of small or very small anterior communicating artery aneurysms comparing surgical clipping and endovascular treatments.

METHODS

A systematic review and meta-analysis were conducted, including studies reporting on both treatment modalities. Eligible studies were identified through PubMed, Cochrane Library, and Embase databases. Pooled analyses with 95% confidence intervals were used to compare treatment effects, and statistical analysis followed PRISMA guidelines.

RESULTS

Thirteen studies with 637 patients were included. Endovascular treatment, predominantly coiling, was performed in 60.3% of patients, while 39.7% underwent surgical management. Endovascular treatment exhibited an 18% retreatment rate, contrasting with 0% in the surgery group. Mortality rates were 3% and 6% for endovascular and surgical treatments, respectively. Overall complications occurred in 1.8% of patients, with intraoperative rupture and cerebral infarction being the most common.

CONCLUSION

In summary, our study indicates a comparable outcome between surgical clipping and endovascular treatment for small ACoA aneurysms, with the former showing a lower retreatment rate. Decision factors include surgeon expertise, healthcare context, and patient age. Further research is needed to refine treatment strategies, considering variations in aneurysm status and evolving techniques.

Flow alteration surgery using a radial artery graft for recurrent ruptured vertebral artery dissecting aneurysm after stent-assisted coil embolization: A case report

BACKGROUND

Ruptured vertebral artery dissecting aneurysm (VADA) is often treated surgically with coil embolization and sometimes recurs. We herein report a case of recurrent ruptured VADA after stent-assisted coil embolization (SAC) that was successfully treated with flow alteration surgery using a radial artery (RA) graft.

CASE DESCRIPTION

A 67-year-old woman presented with headache and coma. Enhanced CT revealed subarachnoid hemorrhage due to right VADA. Since the left VA was hypoplastic, the aneurysm was treated with SAC. However, follow-up angiography revealed recurrence of the aneurysm. Additional embolization was not considered due to the small size of the recurrent lesion and the presence of a stent; therefore, flow alteration surgery was performed using a RA graft. There were no neurological deficits after surgery or recurrence.

CONCLUSION

Flow alteration surgery using a RA graft is useful for recurrent VADA after SAC.

Endovascular Coiling of Ruptured Tiny Saccular Intracranial Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND

The safety and efficacy of endovascular coiling of ruptured tiny saccular intracranial aneurysms (IAs) (≤3 mm) remain unknown.

METHODS

A comprehensive search of PubMed, Embase, Web of Science, and Scorpus databases up to November 15, 2023 was performed. Pooled prevalence was calculated for occlusion rates, recanalization, retreatment, long-term favorable outcome, and procedure-related complications and mortality. Pooled odds ratios were calculated to compare these outcomes between coiling and stent-assisted coiling (SAC).

RESULTS

Forty-two studies with 2166 ruptured tiny saccular IAs treated with coiling were included. The follow-up complete aneurysm occlusion rate was 83.9% (95% CI: 77.2-88.9%). The rates of recanalization and retreatment were 7.7% (95% CI: 5.7-10.2%) and 5.8% (95% CI: 4.5-7.5%). The range of median Hunt and Hess grades was 1.4-2.9 and the favorable outcome rate was 85.6% (95% CI: 81.1-89.2%). The rates of thromboembolism, intraprocedural rupture, and mortality were 4.6% (95% CI: 3.6-5.8%), 5.4% (95% CI: 4.1-7.0%), and 5.6% (95% CI: 4.4-7.2%), respectively. Comparison of coiling and SAC revealed no significant difference, except for a higher likelihood of follow-up complete aneurysm occlusion in SAC (odds ratio [OR] 0.37, 95% CI: 0.17-0.80) and recanalization in the coiling (OR, 3.21 [95% CI, 1.37-7.51]).

CONCLUSIONS

Our meta-analysis demonstrates that coiling for ruptured tiny saccular IA is a feasible, effective, and safe approach that is associated with favorable clinical outcomes in both the short and long term for patients with mild to moderate Hunt and Hess grades.

Computer-assisted microcatheter shaping for intracranial aneurysm embolization: evaluation of safety and efficacy in a multicenter randomized controlled trial

BACKGROUND

This study aimed to evaluate the efficacy, stability, and safety of computer-assisted microcatheter shaping (CAMS) in patients with intracranial aneurysms.

METHODS

A total of 201 patients with intracranial aneurysms receiving endovascular coiling therapy were continuously recruited and randomly assigned to the CAMS and manual microcatheter shaping (MMS) groups. The investigated outcomes included the first-trial success rate, time to position the microcatheter in aneurysms, rate of successful microcatheter placement within 5 min, delivery times, microcatheter stability, and delivery performance.

RESULTS

The rates of first-trial success (96.0% vs 66.0%, P<0.001), successful microcatheter placement within 5 min (96.04% vs 72.00%, P<0.001), microcatheter stability (97.03% vs 84.00%, P=0.002), and 'excellent' delivery performance (45.54% vs 24.00%, P<0.001) in the CAMS group were significantly higher than those in the MMS group. Additionally, the total microcatheter delivery and positioning time (1.05 minutes (0.26) vs 1.53 minutes (1.00)) was significantly shorter in the CAMS group than in the MMS group (P<0.001). Computer assistance (OR 14.464; 95% CI 4.733 to 44.207; P<0.001) and inflow angle (OR 1.014; 95% CI 1.002 to 1.025; P=0.021) were independent predictors of the first-trial success rate. CAMS could decrease the time of microcatheter position compared with MMS, whether for junior or senior surgeons (P<0.001). Moreover, computer assistance technology may be more helpful in treating aneurysms with acute angles (p<0.001).

CONCLUSIONS

The use of computer-assisted procedures can enhance the efficacy, stability, and safety of surgical plans for coiling intracranial aneurysms.

Application of microcatheter shaping based on computational fluid dynamics simulation of cerebral blood flow in the intervention of posterior communicating aneurysm of the internal carotid artery

Introduction

The present study aimed to investigate the application of the aneurysm embolization microcatheter plasticity method based on computational fluid dynamics (CFD) to simulate cerebral blood flow in the interventional treatment of posterior communicating aneurysms in the internal carotid artery and to evaluate its practicality and safety.

Methods

A total of 20 patients with posterior internal carotid artery communicating aneurysms who used CFD to simulate cerebral flow lines from January 2020 to December 2022 in our hospital were analyzed. Microcatheter shaping and interventional embolization were performed according to the main cerebral flow lines, and the success rate, stability, and effect of the microcatheter being in place were analyzed.

Results

Among the 20 patients, the microcatheters were all smoothly placed and the catheters were stable during the in vitro model test. In addition, the microcatheters were all smoothly placed during the operation, with a success rate of 100%. The catheter tips were stable and well-supported intraoperatively, and no catheter prolapse was registered. The aneurysm was completely embolized in 19 cases immediately after surgery, and a small amount of the aneurysm neck remained in one case. There were no intraoperative complications related to the embolization catheter operation.

Conclusion

Microcatheter shaping based on CFD simulation of cerebral blood flow, with precise catheter shaping, leads to a high success rate in catheter placing, stability, and good support, and greatly reduces the difficulty of catheter shaping. This catheter-shaping method is worthy of further study and exploration.

Virtual simulation with AneuShape™ software for microcatheter shaping in intracranial aneurysm coiling: a validation study

Background

The shaping of an accurate and stable microcatheter plays a vital role in the successful embolization of intracranial aneurysms. Our study aimed to investigate the application and the role of AneuShape™ software in microcatheter shaping for intracranial aneurysm embolization.

Methods

From January 2021 to June 2022, 105 patients with single unruptured intracranial aneurysms were retrospectively analyzed with or without AneuShape™ software to assist in microcatheter shaping. The rates of microcatheter accessibility, accurate positioning, and stability for shaping were analyzed. During the operation, fluoroscopy duration, radiation dose, immediate postoperative angiography, and procedure-related complications were evaluated.

Results

Compared to the manual group, aneurysm-coiling procedures involving the AneuShape™ software exhibited superior results. The use of the software resulted in a lower rate of reshaping microcatheters (21.82 vs. 44.00%, p = 0.015) and higher rates of accessibility (81.82 vs. 58.00%, p = 0.008), better positioning (85.45 vs. 64.00%, p = 0.011), and higher stability (83.64 vs. 62.00%, p = 0.012). The software group also required more coils for both small (<7 mm) and large (≥7 mm) aneurysms compared to the manual group (3.50 ± 0.19 vs. 2.78 ± 0.11, p = 0.008 and 8.22 ± 0.36 vs. 6.00 ± 1.00, p = 0.081, respectively). In addition, the software group achieved better complete or approximately complete aneurysm obliteration (87.27 vs. 66.00%, p = 0.010) and had a lower procedure-related complication rate (3.60 vs. 12.00%, p = 0.107). Without this software, the operation had a longer intervention duration (34.31 ± 6.51 vs. 23.87 ± 6.98 min, p < 0.001) and a higher radiation dose (750.50 ± 177.81 vs. 563.53 ± 195.46 mGy, p < 0.001).

Conclusions

Software-based microcatheter shaping techniques can assist in the precise shaping of microcatheters, reduce operating time and radiation dose, improve embolization density, and facilitate more stable and efficient intracranial aneurysm embolization.

Three-dimensional printing-assisted precision microcatheter shaping in intracranial aneurysm coiling

Optimal microcatheter shaping is essential for successful endovascular coiling procedures which is sometimes challenging. Our aim was not only to introduce a new shaping method using three-dimensional (3D) printed vessel models but also to prove its feasibility, efficiency and superiority. This was a retrospective cohort study. From September 2019 to March 2021, 32 paraclinoid aneurysms managed with endovascular coiling were retrospectively included and identified. Sixteen aneurysms were coiled using 3D microcatheter shaping method (3D shaping group), and traditional manual shaping method using shaping mandrels was adopted for another 16 patients (control group). The cost and angiographical and clinical outcomes between the two groups were compared, and the feasibility and effectiveness of the new 3D shaping method were evaluated and described in detail. With technical success achieved in 93.75%, most of the 16 shaped microcatheters using new shaping method could be automatically navigated into the target aneurysms without the assistance of microguidewires and could be assessed with favorable accessibility, positioning and stability. Twenty-seven out of 32 aneurysms (84.38%) were completely occluded with the rate of perioperative complications being 12.50%. Although there was no significant difference between the occlusion rates and complication rates of the two groups, the new shaping method could dramatically decrease the number of coils deployed and reduce the overall procedure time. Patient specific shaping of microcatheters using 3D printing may facilitate easier and safer procedures in coil embolization of intracranial aneurysms with shorter surgery time and less coils deployed.

Optimal microcatheter shaping method customized for a patient-specific vessel using a three-dimensional printer

Objective

In coil embolization of cerebral aneurysms, it is very important to guide microcatheters to the appropriate location in the aneurysm and stabilize them during procedures. To do this, microcatheters need to be properly shaped. In this study, we aim to use a computer application program and a three-dimensional (3D) printer to make a patient-specific shaped microcatheter.

Methods

We simplified, skeletalized, and oversized the existing 3D vascular imaging structures and created the central line structure of the blood vessels. These processes were performed using a computer application program developed by our team. The microcatheters were shaped according to the skeletalized data shape, and the catheterization procedures were simulated using the 3D hollow model of the blood vessel region of interest; the number of hollow models was 10. The compatibility of the microcatheters shaped according to the skeletalized data shape was validated if the microcatheter tip was positioned into the aneurysm.

Results

In all 10 hollow models, the positioning of the microcatheter into the aneurysms was successful following one or two attempts.

Conclusions

When shaping microcatheters during endovascular coil embolization, it may be useful to use central line structures with some expansions customized for a patient-specific vessel using a computer application program and a 3D printer. In the future, it may be necessary to apply this technique to actual patients.

Endovascular Treatment of Tiny Aneurysms With Low-Profile Visualized Intraluminal Support Devices Using a "Compressed" Stent Technique

Objective: To investigate the safety and efficacy of low-profile visualized intraluminal support (LVIS) stent-assisted coiling of intracranial tiny aneurysms using a "compressed" stent technique. Methods: We retrospectively analyzed patients with tiny aneurysms treated in our hospital with LVIS devices using a compressed stent technique. We analyzed patients' imaging outcomes, clinical outcomes, and complications. Results: Forty-two tiny aneurysms in 42 patients were included in this study cohort; 8 patients presented with subarachnoid hemorrhage at admission. The immediate postoperative complete embolization rate was 76.2% (32/42). After an average of 8.5 months of imaging follow-up, the complete embolization rate was 90.5% (38/42), and no aneurysm recanalization occurred. After an average of 24.4 months of clinical follow-up, 95.2% (40/42) of the patients achieved favorable clinical outcomes (modified Rankin scale = 0/1). Operation-related complications occurred in two patients (4.8%); one intraoperative acute thrombosis, and one significant unilateral decreased vision during the postoperative follow-up. Conclusion: LVIS stent-assisted coiling of intracranial tiny aneurysms using a compressed stent technique is safe and effective. Combined stent compression technology is beneficial to maximize the complete embolization of aneurysms and reduce aneurysm recanalization. This study expands the clinical applicability of LVIS stents.

Embolization with Stent-Assisted Technique for Wide-Necked Extremely Small Intracranial Aneurysm with Diameter no more than 2 mm

OBJECTIVE

To investigate the safety and efficacy of embolization with stent-assisted technique for wide-necked extremely small intracranial aneurysms (ESIAs) with diameter no more than 2 mm.

METHODS

From May 2015 through January 2019, 20 wide-necked ESIAs in 19 patients (6 males and 13 females, aged from 38 to 72 years old, average 59 years old) were embolized with stent-assisted technique. All these patients had a total of 29 aneurysms, 7 patients had multiple aneurysms and 1 patient had 2 ESIAs. 12 patients (63.2%) presented with subarachnoid hemorrhage (SAH), 9 of them have a culprit ESIA. The angiographic results before and after operation, procedural complications, and clinical condition with Hunt and Hess grade (H-H) and Fisher grade, as well as Glasgow outcome scale (GOS) at discharge were assessed. Follow-up results were evaluated by computer tomograph angiography (CTA) or digital subtract angiography (DSA).

RESULTS

The mean diameter of aneurysm neck was 1.68 ± 0.21 mm. Complete occlusion with Raymond grade I was achieved in 18 aneurysms (90.9%), 2 aneurysms were subtotal embolization with Raymond grade II (9.1%). All patients were treated with coil embolization with stent-assist technique successfully and all the stents were placed accurately and function well during the procedure. There is no rupture of aneurysm during operation, no coil protrusion to the distal blood vessel, and no cerebral infarction as well. When discharged, all patients recovered well. The follow-up results showed that only one patients with recurrence of aneurysm 27 months after embolization.

CONCLUSION

Embolization with stent-assisted technique for wide-necked ESIAs is safe and effective. However, the follow-up is not long enough in our study and a larger sample size are needed to obtain the long-term efficacy.

＜Editors' Choice＞ Initial experience with in vivo "endovascular shaping" technique that utilizes the vascular configuration for small cerebral aneurysm coiling

Optimal shaping of a microcatheter tip is a key factor in cerebral aneurysm coiling. However, safe cannulation and stabilization of a microcatheter can be technically challenging with small aneurysms requiring precise microcatheter shaping. We devised a new microcatheter shaping technique which bends a microcatheter tip in the intended direction by placing and keeping the tip in the selected branch of the parent artery for 5 minutes: endovascular shaping technique. Our method can complete microcatheter shaping only inside the patient's body; an endovascularly shaped microcatheter will never face a straightening deformity and rotation problem associated with catheter reinsertion. The aim was to assess the feasibility and safety of endovascular shaping for small aneurysm coiling. Clinically, 10 consecutive challenging small terminal-type aneurysms (< 5 mm) treated with endovascular shaping were included. We retrospectively analyzed the newly acquired bend angle of a microcatheter tip after the shaping, the procedural success, and clinical outcomes. An artificial vascular model was used to confirm our findings. In all the 10 patients (three middle cerebral artery, four anterior communicating artery, and three basilar artery aneurysms), the endovascularly shaped microcatheters were bent toward the placement branch at an average of 21.7° and excellently guided into the aneurysms. Coil embolization was successfully accomplished without any complications. The results of the vascular model experiment demonstrated that an endovascularly shaped microcatheter acquired new bend angle toward the placement branch. Endovascular shaping was feasible and safe for small terminal-type aneurysm coiling. Our method can provide accurate shaping and stability during aneurysm coiling procedure.

Microcatheter shaping using three-dimensional printed models for intracranial aneurysm coiling

Background and purpose

Microcatheterization is an important, but also difficult, technique used for the embolization of intracranial aneurysms. The purpose of this study was to investigate the application of three-dimensional (3D) printing technology in microcatheter shaping.

Methods

Nine cases of internal carotid artery posterior communicating artery aneurysm diagnosed by CT angiography were selected, and 3D printing technology was used to build a 3D model including the aneurysm and the parent artery. The hollow and translucent model had certain flexibility; it was immersed in water and the microcatheter was introduced into the water to the target position in the aneurysm, followed by heating the water temperature to 50°C. After soaking for 5 min, the microcatheter was taken out and the shaping was completed. After sterilization, the shaped microcatheter was used for arterial aneurysm embolization and evaluation was conducted.

Results

Nine cases of microcatheter shaping were satisfactory and shaping the needle was not necessary; no rebound was observed. The microcatheter was placed in an ideal position, and the stent-assisted method was used in three cases of wide-neck aneurysm. There were no complications related to surgery.

Conclusion

A new microcatheter shaping method using 3D printing technology makes intracranial artery aneurysm embolization more stable and efficient.

Safety and efficacy of treatment of very small intracranial aneurysms

Purpose

Very small intracranial aneurysms (VSIAs) may cause many neurological complications and even death. Thanks to technological progress and higher quality of non-invasive neuroimaging methods, these pathologies can be investigated sooner and treated earlier. Due to the controversy surrounding invasive treatment of these pathologies, the aim of the study was to analyse methods of treatment, their outcome, and complications in a group of patients with VSIAs.

Material and methods

Out of 444 cases of intracranial aneurysms treated in our centre, 65 aneurysms met the radiological criteria of VSIAs. The parameters – width and length of the aneurysm’s neck and width, length, and height of the aneurysm’s dome – were measured. The analysed parameters were as follows: symptoms upon admission and after treatment, days in hospital, and intraoperative complications. Clinical and radiological intensity of subarachnoid haemorrhage (SAH) was evaluated by using the Hunt-Hess and Fisher scales. The degree of embolisation of the aneurysm after the procedure was assessed using the Montreal Scale. Clinical outcome was assessed by Glasgow Outcome Scale.

Results

50.77% of VSIAs were treated with endovascular procedures and 49.23% with neurosurgical clipping. SAH was presented in 38.46% of patients with VSIAs. Intraoperative complications were presented in 16.92% of patients with VSIAs, and the most common complication was ischaemic stroke. Stents were used in 51.52% of VSIAs. In 69.70% of embolisation procedures at VSIAs complete obliteration was achieved. The average result in the Montreal Scale was 1.31 (SD = 0.66).

Conclusion

VSIAs can be treated as effectively and safely as larger aneurysms, by both endovascular and surgical methods.

Endovascular treatment of small (< 5 mm) unruptured middle cerebral artery aneurysms

Purpose

We report our experience with endovascular treatment of these lesions, with special consideration of angiographic and clinical outcomes and periprocedural complications.

Material and methods

The analysis included treatment results of 19 patients with 20 aneurysms. The aneurysm size ranged from 1.9 to 4.7 mm (mean 3.8, SD 0.7). Clinical examinations with the use of modified Rankin Score and angiographic outcomes were evaluated initially postembolisation and at a minimum follow-up of six months.

Results

Initial post-treatment complete and near-complete aneurysm occlusion was achieved in 19 (95%) cases and incomplete occlusion in one (5%) case. Imaging follow-up, performed in 17 (89.4%) patients, showed no change in the degree of occlusion in 16 (94.1%) patients and coil compaction in one (5.9%). There were no retreatment procedures. The procedure-related mortality rate was 5% (1/20) and was associated with intraprocedural aneurysm rupture. There was a case of a clinically silent coil prolapse into the parent artery. The clinical follow-up evaluation achieved in 17 (89.4%) patients showed no change in clinical status in all followed patients.

Conclusions

Endovascular treatment of small unruptured middle cerebral artery aneurysms is feasible and effective. The procedure-related complications are not negligible, especially in terms of the benign natural course of these lesions.

Cotton-Assisted Surgical Clipping of Very Small Aneurysms: A Two-Center Study

OBJECTIVE

Very small intracranial aneurysms (VSIAs) are challenging to treat because aneurysm tearing and clip slippage can occur during neurosurgical clipping. In this study, we introduce and share our experience with cotton-assisted clipping of VSIAs.

METHODS

We retrospectively analyzed the data of 20 patients with 24 VSIAs treated with cotton-assisted clipping between February 2008 and December 2014 in the Neurosurgery Departments of the First Affiliated Hospital, Soochow University and Taizhou People's Hospital. During surgery, 2 aneurysm necks were torn. To treat the tears, we wrapped rectangular cotton pads around the parental arteries at the site of rupture. The remaining 22 aneurysms were clipped after being wrapped in cotton pads.

RESULTS

The 2 aneurysm ruptures were successfully repaired with cotton-assisted clipping. In the remaining 22 aneurysms, no cases of aneurysm clip slippage or aneurysm rupture occurred. Patients were followed up on average for 59.0 months (range, 30-113 months). Of the 20 patients, the 16 patients with preoperative Hunt-Hess grades of 1-3 recovered well after the surgery (Glasgow Outcome Scale [GOS] score, 5). Of the 4 patients with Hunt-Hess grades of 4-5, 3 had a good recovery (GOS scores, 4-5), and 1 patient died of heart disease 6 months after being discharged from the hospital; this patient had a GOS score of 4 at the time of discharge.

CONCLUSIONS

Cotton-assisted clipping could prevent aneurysm clip slipping and aneurysm rupture and facilitate the repair of aneurysm neck tears. This technique is a useful alternative therapy for VSIAs.

Precision microcatheter shaping in vertebrobasilar aneurysm coiling

BACKGROUND

Inventing an optimal curve on a microcatheter is required for successful intracranial aneurysm coiling. Shaping microcatheters for vertebrobasilar artery aneurysm coiling is difficult because of the vessel's long, tortuous and mobile anatomy. To overcome this problem, we devised a new method of shaping the microcatheter by using the patient's specific vessel anatomy and the highly shapable microcatheter. We report our preliminary results of treating posterior circulation aneurysms by this method.

METHODS

An unshaped microcatheter (Excelsior XT-17; Stryker Neurovascular, Fremont, CA, USA) was pretreated by exposure to the patient's vessel for five minutes. The microcatheter was placed in the vicinity of the targeted aneurysm and was left in contact with the patient's vessel before extraction. This treatment precisely formed a curve on the microcatheter shaft identical to the patient's vessel anatomy. Following the pretreatment, the tip of the microcatheter was steam shaped according to the long axis of the target aneurysm. Five consecutive vertebrobasilar aneurysms were treated using this shaping method and evaluated for the clinical and anatomical outcomes and microcatheter accuracy and stability.

RESULTS

All of the designed microcatheters matched the vessel and aneurysm anatomy except in one case that required a single modification. All aneurysms were successfully catheterized without the assistance of a microguidewire, and matched the long axis of the aneurysm. All microcatheters retained stability until the end of the procedure.

CONCLUSIONS

A precise microcatheter shaping for a vertebrobasilar artery aneurysm may be achieved by using the patient's actual vessel anatomy and the highly shapable microcatheter.

Ultra-small diameter coils for treatment of intracranial aneurysms

This study reports our initial clinical experience treating very small intracranial aneurysms using only Target® Nano™ coils. Retrospective angiographic and clinical analysis was performed on a non-randomized single arm registry of all intracranial aneurysms treated with only Target® Nano™ coils (1 mm and 1.5 mm diameter only) during a 12 month period at two academic hospitals. Fourteen patients with 14 intracranial aneurysms were treated. The maximum diameter of saccular aneurysms treated ranged from 1.5 to 3.5 mm; minimum aneurysm diameter was 1.1 to 2 mm. The immediate complete aneurysm occlusion rate was 86% (12/14), and a small residual within the aneurysm was seen in 14% (2/14) of cases. Packing density from coils ranged between 24% and 83% (mean 51%). The immediate complication rate was 0% (0/14). The angiographic/MR angiography follow-up period was 22 to 70 weeks (mean 37 weeks) with an overall complete occlusion rate of 9/11 (81%), recurrence in 18% (2/11), and lack of follow-up in three cases, two due to death during hospitalization and one procedure not yet due for imaging follow-up. Both patients who died presented with brain aneurysm ruptures prior to treatment. Both recurrences were retreated with repeat coiling procedures. Our initial results using only Target® Nano™ coils for the endovascular treatment of very small intracranial aneurysms have demonstrated initial good safety and efficacy profiles.

Health-Related Quality of Life Dynamics 2 Years Following Aneurysmal Subarachnoid Hemorrhage: A Prospective Cohort Study Using EQ-5D

BACKGROUND

Previous studies have shown that aneurysmal subarachnoid hemorrhage (aSAH) affects health-related quality of life (HRQoL) to a large extent. However, longitudinal studies on HRQoL after aSAH are scarce, and there is limited knowledge whether different HRQoL dimension scores change over time, and if so, if the scoring differs from results from the general population.

OBJECTIVE

To evaluate HRQoL dynamics over time, 2 years following aSAH, and compare the results with general population.

METHODS

In a prospective cohort design, 88 consecutive aSAH patients (85% of eligible) were followed up with the generic HRQoL instrument EQ-5D at 3 time points: 6 months, 1 year, and 2 years after the onset. Data were collected in 2006 to 2009, and the results were compared with a general population sample from the Stockholm Public Health Survey 2006, matched by age and sex.

RESULTS

Overall HRQoL in the aSAH sample was stationary over time. Improved function was only found in the usual activities dimension (P = .026). HRQoL was most affected in participants reporting comorbidity. Compared with the general population, women in the aSAH sample reported significantly more problems in 4 out of 5 dimensions (mobility, self-care, usual activities, and anxiety/depression). Men in the aSAH sample reported significantly more problems in the usual activities dimension in comparison to the general population.

CONCLUSION

HRQoL is stationary during the first 2 years following aSAH, and is significantly worse when compared to the general population. Rehabilitation efforts should be initiated shortly after hospitalization.

Clinical and angiographic outcomes following endovascular treatment of very small (3 mm or smaller) intracranial aneurysm: A single-center experience

Treatments for very small (3 mm or smaller) intracranial aneurysms (VSAs) remain controversial. The aim of this study was to evaluate the efficacy of endovascular treatment for VSAs and to evaluate clinical risk factors associated with complications.This retrospective study enrolled 82 VSA patients who underwent coil embolization in our institution. Angiographic outcomes were assessed according to the Meyers classification. The clinical results were evaluated using the modified Rankin scale (mRS) immediately after coiling, at discharge, and during follow-up. A Mann-Whitney U test was performed for non-normally distributed continuous variables. A Pearson χ test or Fisher's exact test was performed for categorical variables.Among 82 aneurysms, 54 were treated with stent-assisted coiling (SAC) embolization. Thromboembolic complications were seen in 2 patients (2.4%). Intraoperative rupture occurred in 4 patients (4.9%). Other adverse events occurred in 2 patients (2.4%). Two patients (2.4%) had permanent disabling neurologic deficit (mRS 3-6) because of complications. The overall mortality rate was 1.2%. Adverse events were correlated with the location of aneurysms (P = .02), Fisher grade (P = .01), and treatment experience (P = .03). Patients with middle cerebral artery (MCA) bifurcation and anterior communicating artery (ACoA) aneurysms were more likely to experience a higher incidence of complication. Thirty-five patients underwent angiographic follow-up. The complete occlusion rate improved from an immediate 37.8% to 80.0% at follow-up.In the short term, coiling is a safe and effective approach for the treatment of VSAs. SAC may be associated with a high rate of further occlusion during short-term follow-up. Endovascular treatment of VSAs at middle cerebral artery bifurcation or anterior communicating artery is associated with a higher incidence of complications.

Microcatheter shaping using intravascular placement during intracranial aneurysm coiling

Background The selection of a pre-shaped microcatheter or a shaping method must be carefully considered for successful aneurysm coiling. The objective of this report is to verify the use of intravascular placement to establish an appropriate microcatheter shape. Methods Fifteen patients (15 aneurysms) were included in this study because of the predicted difficulty of microcatheter insertion and stabilisation. The SL-10 straight microcatheter was inserted into the parent artery until the tip of the catheter passed through the neck of the aneurysm. After 5 minutes, the microcatheter was pulled out and the shape acquired from intravascular placement was confirmed and compared with the three-dimensional rotational angiography. In addition, the microcatheter tip was steam-shaped for coiling and coil embolisation was performed. A silicone flow model was also used to confirm our findings. The first experiment compared the bend angle in four different microcatheters placed in the model for 5 minutes. In the second experiment, the SL-10 straight microcatheter was placed in the model, and the bend angle was measured at 2.5, 5, 7.5 and 10 minutes to observe the changes in bend angle over time. Results The SL-10 straight microcatheter, in place for 5 minutes, acquired a shape similar to the patient's own vessel. Among the 15 patients included, 13 were treated using an intravascular shaped microcatheter. In the flow model experiments, the SL-10 most easily acquired the vessel shape, and the shape change stabilised after 5 minutes. Conclusion Shaping the SL-10 straight microcatheter using intravascular placement is an effective shaping method for aneurysm coil embolisation.

Stent-Assisted Coiling May Prevent the Recurrence of Very Small Ruptured Intracranial Aneurysms: A Multicenter Study

OBJECTIVE

To evaluate the safety and efficacy of endovascular treatments, including stent-assisted coiling, of very small (≤3 mm), ruptured intracranial aneurysms.

METHODS

Ninety-three endovascularly treated patients with very small ruptured aneurysms were recruited from 4 high-volume centers between September 2010 and February 2014. Factors influencing procedural complications and outcomes were analyzed.

RESULTS

Fifty-one (54.8%) aneurysms were treated by stent-assisted coiling, 41 (44.1%) by coiling alone, and 1 (1.1%) by balloon-assisted coiling. Intraprocedural or postprocedural complications occurred in 13 patients (14.0%): coil migration in 1, intraprocedural rupture in 1, hydrocephalus in 6, and ischemic event in 1. No tested factor was able to predict procedural complications. Angiographic follow-up of 67 aneurysms (72%) revealed recurrence in 5 patients (7.5%). One recurrent case was treated initially by stent-assisted coiling and the remaining four by coiling alone (P = 0.044). Multivariate regression analysis showed that coiling alone was significantly associated with aneurysm recurrence (odds ratio, 13.8; 95% confidence interval, 1.1-175.3; P = 0.043).

CONCLUSIONS

Endovascular treatment of very small ruptured aneurysms was safe and effective and was not associated with a high rate of intraprocedural rupture. Treatment with the use of stents significantly lowered the recurrence rate without additional risks.

Intra-arterial versus intravenous abciximab therapy for thromboembolic complications of neuroendovascular procedures: case review and meta-analysis

BACKGROUND

Abciximab is used to treat thromboembolic complications of neuroendovascular procedures, but outcomes of treatment are not well defined.

OBJECTIVE

To examine the angiographic and clinical outcomes based on route of abciximab administration and degree of vessel recanalization.

MATERIALS AND METHODS

A prospectively maintained database of neuroendovascular procedures performed between January 2004 and May 2015 was retrospectively reviewed to identify cases with thromboembolic complications treated with abciximab. In these cases, route of administration, degree of vessel recanalization, and presence or absence of infarction were determined. A meta-analysis of similar cases in the literature was also performed.

RESULTS

Abciximab was administered in 0.24% (47 of 19 566) of procedures to treat thromboemboli in 59 vessels. Angiographic improvement was seen in 94% after IA therapy and 79% after IV therapy (p=0.133). In our meta-analysis of 391 treated patients, angiographic improvement was greater after IA (91.7%) than IV (77.4%) treatment (p<0.001). Postprocedural infarction occurred more frequently with distal lesions (42%) than local lesions (12%) (p=0.014), and occlusive lesions (36%) than non-occlusive lesions (4.8%) (p=0.010). Infarction was significantly less common with complete angiographic resolution (0%) than with partial or no improvement (54%) (p<0.001). Symptomatic intracranial hemorrhage occurred in 2.1%.

CONCLUSIONS

Abciximab produces a high rate of angiographic improvement and a low incidence of postprocedural infarct in neuroendovascular procedures complicated by thromboemboli. IA abciximab produces greater angiographic improvement than IV treatment. Postprocedural infarction is less common in patients with complete angiographic response than in those with partial or no response.

Consecutive Endovascular Treatment of 20 Ruptured Very Small (<3 mm) Anterior Communicating Artery Aneurysms

BACKGROUND

Small aneurysms located at the anterior communicating artery carry significant procedural challenges due to a complex anatomy. Recent advances in endovascular technologies have expanded the use of coil embolization for small aneurysm treatment. However, limited reports describe their safety and efficacy profiles in very small anterior communicating artery aneurysms.

OBJECTIVE

We sought to review and report the immediate and long-term clinical as well as radiographic outcomes of consecutive patients with ruptured very small anterior communicating artery aneurysms treated with current endovascular coil embolization techniques.

METHODS

A prospectively maintained single-institution neuroendovascular database was accessed to identify consecutive cases of very small (<3 mm) ruptured anterior communicating artery aneurysms treated endovascularly between 2006 and 2013.

RESULTS

A total of 20 patients with ruptured very small (<3 mm) anterior communicating artery aneurysms were consecutively treated with coil embolization. The average maximum diameter was 2.66 ± 0.41 mm. Complete aneurysm occlusion was achieved for 17 (85%) aneurysms and near-complete aneurysm occlusion for 3 (15%) aneurysms. Intraoperative perforation was seen in 2 (10%) patients without any clinical worsening or need for an external ventricular drain. A thromboembolic event occurred in 1 (5 %) patient without clinical worsening or radiologic infarct. Median clinical follow-up was 12 (±14.1) months and median imaging follow-up was 12 (±18.4) months.

CONCLUSION

This report describes the largest series of consecutive endovascular treatments of ruptured very small anterior communicating artery aneurysms. These findings suggest that coil embolization of very small aneurysms in this location can be performed with acceptable rates of complications and recanalization.

Endovascular Treatment of Very Small Intracranial Aneurysms: Meta-Analysis

BACKGROUND AND PURPOSE

Outcomes of endovascular treatment of very small intracranial aneurysms are still not well-characterized. Recently, several series assessing coil embolization of tiny aneurysms have presented new promising results. Thus, we performed a systematic review and meta-analysis of studies evaluating endovascular treatment of very small intracranial aneurysms.

MATERIALS AND METHODS

We conducted a computerized search of Scopus, Medline, and the Web of Science for studies on endovascular treatment of very small (≤3 mm in diameter) intracranial aneurysms published between January 1996 and May 2015. Using a random-effects model, we evaluated clinical and angiographic outcomes.

RESULTS

Twenty-two studies with 1105 tiny aneurysms (844 ruptured and 261 unruptured) endovascularly treated were included. Postoperative and long-term complete occlusion was achieved in 85% (95% CI, 78%-90%) and 91% (95% CI, 87%-94%) of aneurysms, respectively. The recanalization rate was 6% (95% CI, 4%-11%) and retreatment occurred in 7% (95% CI, 5%-9%) of cases. Seventy-nine percent (95% CI, 64%-89%) of patients had good neurologic outcome at long-term follow-up. Intraprocedural rupture occurred in 7% (95% CI, 5%-9%) of the coiling procedures, while thromboembolic complications occurred in 4% (95% CI, 3%-6%).

CONCLUSIONS

Coil embolization of very small intracranial aneurysms can be performed safely and effectively. In the case of unruptured aneurysms, procedure-related complications are not negligible. Patients and providers should consider such risks when engaged in a shared decision-making process.

The combinational use of dual microcatheter technique and new hypersoft helical coil for endovascular treatment of tiny intracranial aneurysm with difficult geometry

The endovascular coiling of very small ruptured aneurysms with difficult geometry presents a significant treatment challenge because of potential dangerous complications, such as intraprocedural ruptures. We report our initial experience with the use of a dual microcatheter technique, combined with new hypersoft helical coils, for the treatment of these difficult lesions. Fourteen very small aneurysms with a maximum diameter of ≤3 mm that presented difficult configurations, such as a wide neck or an important branch vessel arising from the fundus, were identified using digital subtraction angiography. These lesions were successfully treated using a dual microcatheter technique and new hypersoft helical coils. There were no intraprocedural ruptures or procedure-related thromboembolisms. Complete or near-complete occlusions were achieved in all of the lesions. A Raymond score of RS 1 was achieved in eight of the aneurysms (57.1%) and an RS 2 was achieved in six of the aneurysms (42.9%). The mean packing density was 35.5%. At the last post-procedure clinical follow-up, a good clinical outcome (a modified Rankin scale score of 0-2) was observed in 11 of the patients (91.7%). The result of angiographic follow up in 11 cases showed two recanalized aneurysms. The use of the dual microcatheter technique and new hypersoft helical coil allowed for stable coil framing and good packing in geometrically difficult tiny aneurysms and presented a low rate of adverse events related to the procedure. The technique provided an efficient strategy for treating very small aneurysms with difficult configurations and high risks.

Expanding Endovascular Therapy of Very Small Ruptured Aneurysms with the 1.5-mm Coil

BACKGROUND

Very small ruptured aneurysms (≤3 mm) demonstrate a significant risk for procedural rupture with endovascular therapy. Since 2007, 1.5-mm-diameter coils have been available (Micrus, Microvention, and ev3), allowing neurointerventionalists the opportunity to offer patients with very small aneurysms endovascular treatment. In this study, we review the clinical and angiographic outcome of patients with very small ruptured aneurysms treated with the 1.5-mm coil.

METHODS

This is a retrospective cohort study in which we examined consecutive ruptured very small aneurysms treated with coil embolization at a single institution. The longest linear aneurysm was recorded, even if the first coil was sized to a smaller transverse diameter. Very small aneurysms were defined as ≤3 mm. Descriptive results are presented.

RESULTS

From July 2007 to March 2015, 81 aneurysms were treated acutely with coils in 78 patients presenting with subarachnoid hemorrhage. There were 5 patients with 3-mm aneurysms, of which the transverse diameter was ≤2 mm in 3 patients. In all 5 patients, a balloon was placed for hemostatic prophylaxis in case of rupture, and a single 1.5-mm coil was inserted for aneurysm treatment without complication. Complete aneurysm occlusion was achieved in 1 patient, residual neck in 2, and residual aneurysm in 2 patients. Aneurysm recanalization was present in 2 patients with an anterior communicating artery aneurysm; a recoiling attempt was unsuccessful in 1 of these 2 patients due to inadvertent displacement and distal coil embolization, but subsequent surgical clipping was successful. Another patient was retreated by surgical clipping for a residual wide-neck carotid terminus aneurysm. One patient died of ventriculitis 3 weeks after presentation; all 4 other patients had an excellent outcome with no rebleed at follow-up (mean 21 months, range 1-62).

CONCLUSION

The advent of the 1.5-mm coil may be used in the endovascular treatment of patients with very small ruptured aneurysms, providing a temporary protection to the site of rupture in the acute phase. If necessary, bridging with elective clipping may provide definitive aneurysm treatment.

Surgical Clipping of Very Small Unruptured Intracranial Aneurysms

BACKGROUND:

Treatment of very small unruptured intracranial aneurysms (VSUIAs, defined as ⩽3 mm) can be indicated in selected circumstances. The feasibility and outcomes of endovascular therapy for VSUIAs have been recently published; however, the efficacy and complication rate of surgical clipping has not been reported in any large series to date.

OBJECTIVE:

We conducted a multicenter study to examine surgical outcomes for VSUIAs.

METHODS:

All consecutive patients undergoing surgery for a VSUIA in 4 neurosurgical centers between October 2001 and December 2012 were retrospectively analyzed.

RESULTS:

In the study, 183 patients (128 women, mean age 51.3 years) were treated with 190 procedures for a total of 228 aneurysms. Most were anterior circulation aneurysms (n = 215). The majority were directly clipped (n = 222, 97.4%), with coagulation or wrapping in the remainder. After 1 reoperation for incomplete clipping, postoperative imaging of 225 aneurysms confirmed complete occlusion in 221 (98.2%), 1 neck remnant (0.44%), and 3 partial occlusions (1.3%). Mortality was 0%. Early postoperative neurological deficit developed in 12 patients (6.6%); posterior circulation location was a significant risk factor for early neurological deficit (P &lt; .001). Middle cerebral artery aneurysms had the lowest rate of postoperative deficits at 1.5% (P = .023). After the initial 30-day perioperative period, all deficits related to treatment of posterior circulation aneurysms recovered; overall neurological morbidity decreased to 2.7% with no mortality.

CONCLUSION:

VSUIA clipping is highly effective and is associated with a low morbidity rate. For VSUIAs selected for treatment, our data support surgical clipping as the modality of choice.

Embolisation of internal carotid artery aneurysm using the double microcatheter technique - a case report

Background

A wide-necked aneurysm is defined as the one with a neck greater than 4 mm in diameter. Embolisation of wide-necked aneurysms is a great challenge for neuroradiologists. To overcome possible complications of endovascular treatment of this type of aneurysms, methods like intracranial stents, balloon remodelling, the double microcatheter and the microcatheter protective technique have been developed.

Case Report

We report a case of embolisation of a 63-year-old woman with a wide-necked aneurysm using the double microcatheter technique. Introduction of the second microcatheter into the aneurysm allowed for crossing two coils and prevented protrusion into the parent vessel, which resulted in successful treatment without postprocedural complications. Both postembolic and follow-up angiography showed complete exclusion of the aneurysm.

Conclusions

The double microcatheter technique, owing to creation of a stable coil frame across the neck of the aneurysm, is suitable for treatment of aneurysms with an adverse dome-to-neck ratio. This technique is easy to perform for an experienced neuroradiologist.

Microcatheter Shaping for Intracranial Aneurysm Coiling Using the 3-Dimensional Printing Rapid Prototyping Technology: Preliminary Result in the First 10 Consecutive Cases

OBJECTIVE

An optimal microcatheter is necessary for successful coiling of an intracranial aneurysm. The optimal shape may be predetermined before the endovascular surgery via the use of a 3-dimensional (3D) printing rapid prototyping technology. We report a preliminary series of intracranial aneurysms treated with a microcatheter shape determined by the patient's anatomy and configuration of the aneurysm, which was fabricated with a 3D printer aneurysm model.

METHODS

A solid aneurysm model was fabricated with a 3D printer based on the data acquired from the 3D rotational angiogram. A hollow aneurysm model with an identical vessel and aneurysm lumen to the actual anatomy was constructed with use of the solid model as a mold. With use of the solid model, a microcatheter shaping mandrel was formed to identically line the 3D curvature of the parent vessel and the long axis of the aneurysm. With use of the mandrel, a test microcatheter was shaped and validated for the accuracy with the hollow model. All the planning processes were undertaken at least 1 day before treatment. The preshaped mandrel was then applied in the endovascular procedure. Ten consecutive intracranial aneurysms were coiled with the pre-planned shape of the microcatheter and evaluated for the clinical and anatomical outcomes and microcatheter accuracy and stability.

RESULTS

All of pre-planned microcatheters matched the vessel and aneurysm anatomy. Seven required no microguidewire assistance in catheterizing the aneurysm whereas 3 required guiding of a microguidewire. All of the microcatheters accurately aligned the long axis of the aneurysm. The pre-planned microcatheter shapes demonstrated stability in all except in 1 large aneurysm case.

CONCLUSION

When a 3D printing rapid type prototyping technology is used, a patient-specific and optimal microcatheter shape may be determined preoperatively.

Double-clip technique for the microneurosurgical management of very small (< 3 mm) intracranial aneurysms

BACKGROUND

The treatment of very small (≤ 3 mm) aneurysms is technically challenging. Mini-clips used for clipping these small aneurysms have a smaller closing force compared with standard clips.

OBJECTIVE

To describe the double-clip technique for very small aneurysms.

METHODS

The double-clip technique, a parallel duplication clipping technique of booster clipping, is used by the senior author for clipping very small aneurysms with morphology suitable for the application of 2 clips. The aneurysm is clipped after application of temporary clip(s), administration of adenosine, or both. An initial mini-clip is applied, leaving a small residual neck sufficient for application of the second mini-clip. A second mini-clip of the same size and shape is applied on the residual neck parallel to the initial clip. The initially applied mini-clip, which is in close contact with the second clip, supports the second clip and prevents its slippage. This technique was retrospectively reviewed over a 13-year period (1997-2009). There were 3246 patients with 4757 aneurysms treated in the same period.

RESULTS

The outcomes of 39 patients with 40 very small aneurysms clipped with the double-clip technique were analyzed. None of the patients had technique-related complications. Postoperative angiograms revealed complete aneurysm occlusion of 39 aneurysms and a small residual neck in 1 aneurysm. No parent artery obstruction was observed in the postoperative angiogram.

CONCLUSION

The double-clip technique is a safe and effective variation of booster clipping in the treatment of very small aneurysms with suitable morphology.

Force characterization of intracranial endovascular embolization: coil type, microcatheter placement, and insertion rate

BACKGROUND

Intraoperative rupture (IOR) is a rare, but potentially morbid complication of endovascular aneurysm coil embolization. Yet, IOR predictors have remained relatively uninvestigated in relation to coil design.

OBJECTIVE

To develop a novel in vitro aneurysm model to characterize forces exerted by coils of different design on the aneurysm during endovascular embolization that are hypothesized to contribute to IOR.

METHODS

A 3-mm saccular aneurysm model was developed with flat latex membrane at the dome apex. Membrane deflection was observed throughout simulated embolization and converted to force measurement. Simultaneous coil insertion and force measurement were accomplished with a compression strength-testing machine. Membrane and insertion forces across coil type, microcatheter tip placement, and insertion rate were evaluated.

RESULTS

Insertion force and force directly on the aneurysm wall exhibited a difference, with framing coils exerting greatest force, followed by filling and finishing coils. Regarding microcatheter placement, a similar graded response in membrane and insertion forces was observed with positioning in the top-third of the aneurysm generating the greatest force compared with central and bottom-third placement. Insertion rate was also a factor with the slowest rate (10 mm/min) exhibiting the greatest membrane force, followed by lower forces at 30 and 50 mm/min. A multiple linear regression model was created to assess the contributions of each factor toward aneurysm forces.

CONCLUSION

Increased force on the aneurysm is associated with framing coil use, microcatheter placement proximal to aneurysm dome, and slow insertion rate. Further characterization remains necessary to reduce IOR risk, especially concerning the contributions of insertion rate.

A retrospective analysis on the natural history of incidental small paraclinoid unruptured aneurysm

OBJECTIVE

The optimal consensus concerning treatment of incidental small paraclinoid unruptured intracranial aneurysms (UIAs) remains controversial. The aim of this retrospective study was to reveal the natural history of small paraclinoid UIAs with the goal of informing the treatment plan.

METHODS

524 patients harbouring 568 paraclinoid UIAs (≤5 mm) were retrospectively evaluated during the mean follow-up of 35.4 months. The aneurysms were divided into two groups with respect to arterial branch: related (ophthalmic and superior hypophyseal artery), and non-related. Medical records were reviewed concerning multiple variables, such as sex, age, hypertension (HTN), diabetes mellitus, smoking and aneurysmal factors (size, arterial relationship, multiplicity and the occurrence of rupture and growth). The cumulative risk and the risk factors of aneurysmal rupture and growth were analysed.

RESULTS

Two aneurysmal (0.35%) ruptures and 17 growths (3.0%) were observed during the follow-up of 1675.5 aneurysm-years with an annual rupture of 0.12% and an annual growth of 1.01%. The cumulative survival without aneurysmal growth reached a significant difference in aneurysms ≥4 mm (p=0.001), HTN (p=0.002), and arterial branch-related location (p=0.001). Multivariate analysis disclosed that aneurysm ≥4 mm (HR, 4.41; p=0.003), HTN (HR, 5.74; p=0.003), arterial branch-related location (HR, 6.04; p=0.002), and multiplicity (HR, 0.27; p=0.042) were significant predictive factors for aneurysm growth.

CONCLUSIONS

Although incidental small paraclinoid UIAs have a relatively lower rupture and growth risk, patients with high-risk factors, including aneurysm ≥4 mm, HTN, arterial branch-related aneurysms, and multiple aneurysms must be monitored closely. The limitation of the retrospective nature of this study should be taken into consideration.

Sole stenting technique for the treatment of uncoilable very small aneurysms in the intracranial internal carotid artery

The treatment of very small aneurysms with diameter of less than 3 mm remains a challenge for both endovascular and surgical treatment. Endovascular treatment of these lesions may be difficult and is associated with a high risk of complications because of their small size. The present study evaluated the safety, feasibility, and efficacy of the endovascular treatment using sole stenting technique for uncoilable very small aneurysms of the intracranial internal carotid artery (ICA). From August 2004 through January 2010, eight very small aneurysms of intracranial ICA in eight patients were treated with endovascular sole stenting technique. All very small aneurysms were ruptured (n = 3) or aneurysms associated with another ruptured (n = 2) and unruptured aneurysms (n = 3) in the same artery. Stents were Neuroform and balloon expandable coronary stents. Stent deployment was carried out without difficulty in all patients. Single stent deployment was done for six aneurysms, and double stents in two aneurysms. The immediate angiographic results were partial occlusion in one case and no occlusion in seven cases. One direct carotid-cavernous fistula occurred during coronary stenting without permanent neurological deficit. No neurological deterioration or hemorrhagic complication was seen during the follow-up period in seven patients. Follow-up angiography (mean 9 months) was available in six patients and revealed complete occlusion in four and no occlusion in two cases. Sole stenting technique may be a feasible and effective therapeutic alternative for uncoilable very small aneurysms. The long-term efficacy and durability of stenting for these lesions remains to be determined in a large series.

Endovascular treatment of very small and very large ruptured aneurysms of the anterior cerebral circulation: a single-center experience

INTRODUCTION

Endovascular treatment of aneurysms has been introduced as a less invasive method for decreasing the rate of aneurysm rerupture and subsequent subarachnoid hemorrhage. The outcome and complication rate for endovascular treatment of very small (≤3 mm) and very large (15-25 mm) intracranial aneurysms has been controversial. Here we report our experience with endovascular coiling of very small and very large ruptured aneurysms of the anterior cerebral circulation.

METHODS

Patients were included in the study if the maximum dimension of the intracranial ruptured aneurysm was reported to be ≤3 mm or 15-25 mm and if the aneurysm was within the anterior cerebral circulation. The largest dimension was calculated using CT angiography and was confirmed by digital subtraction angiography. Endovascular coiling was performed using Guglielmi detachable coils. All patients underwent follow-up contrast MR angiography every 6 months.

RESULTS

A total of 40 cases (18 females and 22 males) were included in this single-center study. Twenty-one very small and 19 very large ruptured aneurysms were analyzed. Preprocedural Hunt and Hess grades were determined. Endovascular coiling was performed successfully in most cases (97.5%), with unsuccessful coiling in 1 patient with a very small ruptured aneurysm. In the very small aneurysm group, the most common location was the anterior communicating artery and, in the large aneurysm group, the most common location was the middle cerebral artery (MCA) bifurcation. The mean follow-up time was 15.08 months (range: 6-30 months). The 6th month modified Rankin scale (mRS) values for very small aneurysm cases were 0 (no symptoms at all) in 16 cases (76.2%) and 1 (no significant disability despite symptoms) in 5 cases (23.80%). For the very large aneurysm cases, the mRS values were 1 in 2 cases (10.5%), 2 in 7 cases (36.8%), 3 in 6 cases (31.6%), 4 in 3 cases (15.8%) and 6 in 1 case (died due to vasospasm 72 h later; 5.2%). The immediate complications that were observed were MCA branch occlusion in 1 very small aneurysm patient and early vasospasms in 3 very large aneurysm patients. The late complication that was observed was recanalization in 1 very small aneurysm case (1/21, 4.76%) and in 5 very large aneurysm cases (5/18, 27.77%).

CONCLUSION

Endovascular treatment of very small aneurysms is an effective method of treatment with acceptable immediate and long-term outcomes. Immediate and long-term complications were more prevalent in very large ruptured aneurysms.

Rate and clinical impact of intra-procedural complications during coil embolisation of ruptured small (3 mm or less) cerebral aneurysms

OBJECTIVE

Coiling of small (≤3 mm) cerebral aneurysms can be technically challenging and is associated with increased procedural-related morbidity and mortality. The authors report the clinical and radiological results following coiling of ruptured small cerebral aneurysms in a single-institution, and define the rates of intra-procedural rupture and thromboembolism.

METHODS

A retrospective analysis was conducted on consecutive patients from 01/01/2008 to 31/12/2010 with subarachnoid haemorrhage (SAH) from ruptured cerebral aneurysms (≤3 mm) managed in a tertiary neurosurgical institution in the United Kingdom.

RESULTS

Of the 108 patients identified, 72 patients (66.7%) underwent coil embolisation. A favourable outcome, defined as a Glasgow outcome score of 4-5, was achieved in 63 (87.5%) of these patients. Intra-procedural complications were observed in 11.1% (±7.3% 95% CI) of cases, wherein the rate of intra-procedural rupture was determined to be 8.3% (±6.4% 95% CI) and intra-procedural thromboembolism to be 2.8% (±3.8% 95% CI).

CONCLUSION

Although coil embolisation of small ruptured cerebral aneurysms is technically feasible and an efficacious means of treatment, it is associated with an increased rate of intra-procedural complications. This should be taken into account when embarking upon treatment of patients with ruptured small cerebral aneurysms.

Time-resolved 3D contrast-enhanced MRA on 3.0T: a non-invasive follow-up technique after stent-assisted coil embolization of the intracranial aneurysm

Objective

To evaluate the usefulness of time-resolved contrast enhanced magnetic resonance angiography (4D MRA) after stent-assisted coil embolization by comparing it with time of flight (TOF)-MRA.

Materials and Methods

TOF-MRA and 4D MRA were obtained by 3T MRI in 26 patients treated with stent-assisted coil embolization (Enterprise:Neuroform = 7:19). The qualities of the MRA were rated on a graded scale of 0 to 4. We classified completeness of endovascular treatment into three categories. The degree of quality of visualization of the stented artery was compared between TOF and 4D MRA by the Wilcoxon signed rank test. We used the Mann-Whitney U test for comparing the quality of the visualization of the stented artery according to the stent type in each MRA method.

Results

The quality in terms of the visualization of the stented arteries in 4D MRA was significantly superior to that in 3D TOF-MRA, regardless of type of the stent (p < 0.001). The quality of the arteries which were stented with Neuroform was superior to that of the arteries stented with Enterprise in 3D TOF (p < 0.001) and 4D MRA (p = 0.008), respectively.

Conclusion

4D MRA provides a higher quality view of the stented parent arteries when compared with TOF.

Optimization of MR Parameters of 3D TOF-MRA for Various Intracranial Stents at 3.0T MRI

Purpose

The in-stent signal reduction of the stented artery caused by susceptibility artifact or radiofrequency shielding artifact limited the use of time-of-flight MR angiography (TOF-MRA) as a follow-up tool after intracranial stenting. We showed the degree of an artifact according to different stent types, and optimized MR parameters for TOF-MRA in patients with intracranial stent on 3.0 T MRI.

Materials and Methods

Four stents (Neuroform, Wingspan, Solitaire, and Enterprise) were placed in a vascular flow phantom and imaged by changing flip angle (FA; 20°,30°,40°,50° and 60°) and bandwidth (BW; 31, 42 and 62.5 KHz) using TOF-MRA. Source data of each image set with different FA and BW were reconstructed with the maximal intensity projection (MIP) technique, and MIP images were used to evaluate the in-stent signal reduction of each stent according to the change of MR parameters. The in-stent signal reduction was assessed by calculating the relative in-stent signal (RIS) inside the stent as compared with background and signal intensity of the tube outside the stent. The optimal FA and BW of each stent were determined by comparing the RIS in each stent by one-sample t test. Finally, one neuroradiologist chose one image set with the best image quality.

Results

The mean RIS for Neuroform, Wingspan, Solitaire and Enterprise stent was 66.3 ± 6.0, 44.2 ± 5.8, 22.8 ± 3.3 and 8.2 ± 2.9, respectively. The significantly high RIS of each stent was obtained with FA/BW value of 20°/31 KHz (Neuroform), 20°/31 KHz and 30°/42 KHz (Wingspan), 40°/42 KHz and 50°/31 KHz (Solitaire) and 40°/31 KHz and 50°/31 KHz (Enterprise). Among these MIP images with significantly high RIS, images with FA/BW value of 20°/31 KHz (Neuroform and Wingspan) and 50°/31 KHz (Solitaire and Enterprise) had the best image quality.

Conclusion

The degree of artifact was variable according to the design of each intracranial stent. The luminal visualization of closed-cell design stents such as Solitaire and Enterprise can be improved by higher FA. Thus, MR parameter should be adjusted according to the type of intracranial stents.

Prevalence of unruptured intracranial aneurysm on MR angiography

Objective

To evaluate the prevalence of incidentally found unruptured intracranial aneurysms (UIAs) on the brain MR angiography (MRA) from a community-based general hospital.

Materials and Methods

This was a prospectively collected retrospective study, carried out from January 2004 to December 2004. The subjects included 3049 persons from a community-based hospital in whom MRA was performed according to a standardized protocol in an outpatient setting. Age- and sex-specific prevalence of UIAs was calculated. The results by MRA were compared with intra-arterial digital subtraction angiography (DSA) findings.

Results

Unruptured intracranial aneurysms were found in 137 (5%) of the 3049 patients (M:F = 43:94; mean age, 60.2 years). The prevalence of UIAs was 5% (n = 94) in women and 4% (n = 43) in men, respectively (p = 0.2046) and showed no age-related increase. The most common site of aneurysm was at the distal internal carotid artery (n = 64, 39%), followed by the middle cerebral artery (n = 40, 24%). In total, 99% of aneurysms measured less than 12 mm, and 93% of aneurysms measured less than 7 mm. Direct comparisons between MRA and DSA were available in 70 patients with 83 UIAs; the results revealed two false positive and two false negative results.

Conclusion

This community-hospital based study suggested a higher prevalence of UIAs observed by MRA than previously reported. These findings should be anticipated in the design and use of neuroimaging in clinical practice.