Endovascular and Surgical Treatment of Unruptured MCA Aneurysms: Meta-Analysis and Review of the Literature

Woven endobridge embolization versus microsurgical clipping for unruptured wide-neck cerebral aneurysms on middle cerebral artery bifurcation

Woven EndoBridge (WEB) is an endovascular treatment for wide-neck bifurcation aneurysms (WNBAs). This study aimed to clarify the efficacy and safety of the WEB comparing to clipping for treating the middle cerebral artery (MCA) WNBAs. For the matched analysis, we designed a retrospective, tertiary, single-center study including 288 MCA WNBAs treated with WEB (n = 37) or clipping (n = 251). Inverse probability of treatment weighting (IPTW) for the main analysis and 1:2 propensity score matching for the sensitivity analysis were used to adjust for aneurysm geometric parameters. Morbidity, major complications, and aneurysm occlusion grade were assessed at 1 year. In the IPTW analysis, no significant difference was observed in morbidity (2.1% vs. 1.6%, odds ratio [OR]: 1.34, p = 0.776) and major complications (3.3% vs. 3.1%, OR: 1.08, p = 0.926). Adequate aneurysm occlusion was achieved in 76.1% of the WEB group and 97.4% of the clipping group (OR: 0.09, p < 0.001). In line with the main analysis, the 1:2 propensity score matching analysis revealed no significant difference in the morbidity (OR: 2.00, 95% CI: 0.13-31.98, p = 0.624). This study supports that microsurgical clipping still requires to play a vital role, but WEB could be an alternative option for WNBAs in the MCA.

Open Microsurgical Versus Endovascular Management of Unruptured and Ruptured Brain Aneurysms

Open microsurgical and endovascular techniques are the 2 primary strategies for treating intracranial aneurysms. Microsurgical clipping and adjuvant technical maneuvers are well-established techniques with a track record for high occlusion rates and durable repairs. Endovascular, endosaccular, and extrasaccular therapies are associated with lower peri-procedural morbidity but with generally higher rates of retreatment. We discuss key clinical and anatomic considerations in treatment decision-making and compare the risks and benefits of microsurgical vs endovascular treatment within each context.

Virtual reality guided focused Sylvian approach for clipping unruptured middle cerebral artery aneurysms

Objective

The increasing prevalence of unruptured intracranial aneurysms, detected through advanced brain imaging, necessitates a cautious approach to surgical intervention, with a focus on minimizing associated risks. This retrospective study explores the safety and better aesthetic outcomes of a Virtual Reality (VR) guided Focused Sylvian Approach (FSA) in comparison to the standard Pterional Surgical Approach (SPA) for the clipping of unruptured small-medium-size (<10 mm) Middle Cerebral Artery (MCA) aneurysms.

Methods

23 patients with 23 unruptured MCA aneurysms underwent the VR-guided FSA from June 2020 to September 2023, while 22 patients with 23 unruptured MCA aneurysms who underwent SPA were retrospectively recruited from the medical records database from January 2017 to May 2020. The comparative analysis involved surgical duration, postoperative complications, hospital stay, and a three-month follow-up patient's sequela survey.

Results

All aneurysms were effectively treated. The FSA procedure demonstrated a shorter surgical duration compared to the SPA group (164 ± 48 min vs. 196 ± 133 min, P = 0.2974). Despite a slightly higher median age in the FSA group (59 vs. 56 years), the median hospital stay was shorter in the FSA group (6 days) compared to the SPA group (7 days). The SPA group exhibited a higher incidence of complications (17/23) including cephalalgia, scar irritation, scar numbness, and temporal muscle dysfunction, compared to the FSA group (1/23), with a statistical significance of P < 0.05. Although FSA cannot demonstrate significant surgical efficiency in surgical duration and hospitalization, its superior aesthetics and preservation of temporalis muscle function compared to the SPA group.

Conclusion

The VR-guided FSA offers improved aesthetics and preservation of muscle function compared to the SPA. Our retrospective study underscores the potential benefits of VR-guided, personalized, focused Sylvian approaches for managing unruptured small-medium-size MCA aneurysms.

Feasibility, Safety, and Efficacy of Endovascular vs. Surgical Treatment of Unruptured Multi-Sac Intracranial Aneurysms in a Single-Center Retrospective Series

PURPOSE

Multi-sac aneurysms (MSAs) are not uncommon, but studies on their management are scarce. This study aims to evaluate and compare the feasibility, safety, and efficacy of MSAs treated with either clipping or coiling after interdisciplinary case discussion at our center.

MATERIALS AND METHODS

We retrospectively analyzed MSAs treated by microsurgical clipping, coiling, or stent-assisted coiling (SAC). Treatment modalities, complications, angiographic results, and clinical outcomes were evaluated. Major neurological events were defined as a safety endpoint and complete occlusion as an efficacy endpoint.

RESULTS

Ninety patients (mean age, 53.2±11.0 years; 73 [81.1%] females) with MSAs met our inclusion criteria (clipping, 50; coiling, 19; SAC, 21). Most aneurysms were located in the middle cerebral artery (48.9%). All clipping procedures were technically successful, but endovascular treatment failed in 1 coiling case, and a switch from coiling to SAC was required in 2 cases. The major event rates were 4.0% after clipping (1 major stroke and 1 intracranial hemorrhage) and 0% after endovascular therapy (P=0.667). At mid-term angiographic follow-up (mean 12.0±8.9 months), all 37 followed clipped aneurysms were completely occluded, compared to 8/17 (41.7%) after coiling and 11/15 (73.3%) after SAC (P<0.001). Coiling was significantly associated with incomplete occlusion in the adjusted analysis (odds ratio, 11.7; 95% confidence interval, 2.7-52.6; P=0.001).

CONCLUSION

Both endovascular and surgical treatment were feasible and safe for MSAs. As coiling was associated with comparatively high recanalization rates, endovascular treatment may be preferred with stent support.

Impact of size ratio on thromboembolic events based on diffusion-weighted imaging after coil embolization for unruptured basilar apex aneurysm

PURPOSE

Coil embolization is one of the main endovascular treatment for basilar apex aneurysms (BAAs), and thromboembolic events are important complications of coil embolization. Even in small aneurysms, there is a risk of rupture, and aggressive treatment should be considered for unruptured BAAs. Using diffusion-weighted imaging (DWI), the study aimed to investigate thromboembolic events after coil embolization for unruptured BAAs by focusing on the absolute aneurysm size and relative aneurysm size (size ratio [SR]).

METHODS

To evaluate the predictors of thromboembolic events, patients were divided into those with and without hyperintensity on DWI after coil embolization. Patient and radiographic characteristics were compared between the two groups. SR was defined as the maximum aneurysm diameter divided by the average parent artery diameter.

RESULTS

Fifty-six unruptured BAAs in 56 patients were investigated. The mean aneurysm size and SR were 7.61 ± 2.18 mm and 2.74 ± 1.45, respectively. Postprocedural hyperintensity on DWI was detected in 17 patients (30.4%). SR was significantly larger in the group with hyperintensity on DWI (3.75 ± 1.97 vs. 2.3 ± 0.82, P < 0.01) in the univariate analysis. Multivariate analysis revealed that SR> 3.0 was a significant predictor of thromboembolic events after coil embolization for unruptured BAAs (odds ratio: 12.15; 95% confidence interval: 2.95-49.98; P < 0.01).

CONCLUSIONS

This study showed that SR is a predictor of thromboembolic events after coil embolization for unruptured BAAs. Therefore, if even in small BAAs, if the BAAs dome height is large compared to the diameter of the posterior cerebral artery (e.g., there is a large SR), preoperative evaluation of the use of antiplatelet therapy is important, particularly to prevent thromboembolic events.

Outflow angle: a risk factor for thromboembolic complications in coil embolisation for treating unruptured middle cerebral artery bifurcation aneurysms

BACKGROUND

Thromboembolic complications are a relevant risk in coil embolisation of cerebral aneurysms. This retrospective study aimed to assess the treatment outcomes of unruptured middle cerebral artery (MCA) bifurcation aneurysms and the predictors for thromboembolic complications based on the aneurysm morphological characteristics. We examined the following three features: inflow angle, outflow angle (OA), and bifurcation angle, formed by the aneurysm and neighbouring blood vessels.

METHODS

A total of 32 MCA bifurcation aneurysms were retrospectively investigated in 32 patients treated consecutively at our institute between April 2008 and March 2019. The predictors for thromboembolic complications were analysed in two groups: patients with and without thromboembolic complications.

RESULTS

Perioperative thromboembolic complications were detected in six patients (18.8%), including two and six intra- and post-procedural thromboembolic complications, respectively; all cases were resolved. Regarding the aneurysms' morphological characteristics, the group with thromboembolic complications showed a significantly smaller OA (55.58° ± 14.05° vs. 86.04° ± 28.58°, P = 0.01) than the group without complications. Multivariate analysis revealed that smoking habits and OA < 70° were significant predictors of thromboembolic complications (smoking habits: P = 0.01, odds ratio [OR]: 6.89, 95% confidence interval [CI]: 3.78-12.62; OA < 70°: P = 0.04, OR: 3.19, 95% CI: 1.52-6.56).

CONCLUSIONS

Our findings indicate significant pre-procedural predictors of thromboembolic complications to consider for safe treatment; clipping should be preferred to coil embolisation in high-risk patients. The method of choice should be considered in each case to allow the safe treatment of unruptured MCA aneurysms.

Procedural complications in patients undergoing microsurgical treatment of unruptured intracranial aneurysms: a single-center experience with 1923 aneurysms

BACKGROUND

With the growing use of endovascular therapy (EVT) to manage unruptured intracranial aneurysms (IAs), detailed information regarding periprocedural complication rates of microsurgical clipping and EVT becomes increasingly important in determining the optimal treatment for individual cases. We report the complication rates associated with open microsurgery in a large series of unruptured IAs and highlight the importance of maintaining surgical skill in the EVT era.

METHODS

We reviewed all cases of unruptured IAs treated with open microsurgery by a single neurosurgeon between July 1997 and June 2019. We analyzed surgical complications, deaths, and patient-reported outcomes.

RESULTS

A total of 1923 unruptured IAs in 1750 patients (mean age 44 [range: 6-84], 62.0% [1085/1750] female) were treated surgically during the study period. Of the aneurysms treated, 84.9% (1632/1923) were small, 11.1% (213/1923) were large, and 4.1% (78/1923) were giant. Aneurysm locations included the middle cerebral artery (44.2% [850/1923]), internal carotid artery (29.1% [560/1923]), anterior cerebral artery (21.0% [404/1923]), and vertebrobasilar system (5.7% [109/1923]). The overall mortality rate was 0.3% (5/1750). Surgical complications occurred in 7.4% (129/1750) of patients, but only 0.4% (7/1750) experienced permanent disability. The majority of patients were able to return to their preoperative lifestyles with no modifications (95.9% [1678/1750]).

CONCLUSIONS

At a high-volume, multidisciplinary center, open microsurgery in carefully selected patients with unruptured IAs yields favorable clinical outcomes with low complication rates. The improvement of EVT techniques and the ability to refer cases for EVT when a high complication rate with open microsurgery was expected have contributed to an overall decrease in surgical complication rates. These results may serve as a useful point of reference for physicians involved in treatment decision-making for patients with unruptured IAs.

Hospital staff, volunteers' and patients' perceptions of barriers and facilitators to communication following stroke in an acute and a rehabilitation private hospital ward: a qualitative description study

OBJECTIVES

To explore barriers and facilitators to patient communication in an acute and rehabilitation ward setting from the perspectives of hospital staff, volunteers and patients following stroke.

DESIGN

A qualitative descriptive study as part of a larger study which aimed to develop and test a Communication Enhanced Environment model in an acute and a rehabilitation ward.

SETTING

A metropolitan Australian private hospital.

PARTICIPANTS

Focus groups with acute and rehabilitation doctors, nurses, allied health staff and volunteers (n=51), and interviews with patients following stroke (n=7), including three with aphasia, were conducted.

RESULTS

The key themes related to barriers and facilitators to communication, contained subcategories related to hospital, staff and patient factors. Hospital-related barriers to communication were private rooms, mixed wards, the physical hospital environment, hospital policies, the power imbalance between staff and patients, and task-specific communication. Staff-related barriers to communication were staff perception of time pressures, underutilisation of available resources, staff individual factors such as personality, role perception and lack of knowledge and skills regarding communication strategies. The patient-related barrier to communication involved patients' functional and medical status. Hospital-related facilitators to communication were shared rooms/co-location of patients, visitors and volunteers. Staff-related facilitators to communication were utilisation of resources, speech pathology support, staff knowledge and utilisation of communication strategies, and individual staff factors such as personality. No patient-related facilitators to communication were reported by staff, volunteers or patients.

CONCLUSIONS

Barriers and facilitators to communication appeared to interconnect with potential to influence one another. This suggests communication access may vary between patients within the same setting. Practical changes may promote communication opportunities for patients in hospital early after stroke such as access to areas for patient co-location as well as areas for privacy, encouraging visitors, enhancing patient autonomy, and providing communication-trained health staff and volunteers.

Endovascular Treatment of Ruptured Middle Cerebral Artery Bifurcation Aneurysms. A Retrospective Observational Study of Short- and Long-Term Follow-Up

PURPOSE

With the introduction of new devices and the development of approved devices, endovascular techniques are more and more considered as a treatment option for middle cerebral artery aneurysms (MCA). In this study, we present data on ruptured MCA aneurysms that were treated endovascularly in our hospital.

MATERIAL AND METHODS

In a retrospective case series of ruptured MCA bifurcation aneurysms, 118 (94%) cases were managed endovascularly between May 2008 and July 2017. Most were managed with coiling (= 62) and the remaining were managed with stent-assisted-coiling (= 35) and endovascular flow disruptor (WEB-device) (= 21). We measured the clinical outcome at the time of discharge and long-term follow-up on the modified Rankin Scale (mRS) and evaluated the rates of periprocedural complications and retreatment.

RESULTS

A good clinical outcome (mRS 0-2) at discharge was achieved in 58.5% of these cases. Mortality rate was 19.5%. Nine aneurysms required retreatment. Eighty-three percent demonstrated a good clinical outcome at long-term follow-up (mRS 0-2). In total, 6 (5.1%) procedure-related complications and 10 (8.5%) disease-related complications occurred. No significant difference between reintervention, complications or outcome was found between the employment of different devices (P > 0.05). Endovascular treatment of ruptured MCA aneurysms at our practice showed similar morbidity and mortality to data published about surgical clipping.

CONCLUSION

The endovascular device evolution permits a feasible and safe treatment of ruptured MCA bifurcation aneurysms. Endovascular treatment can therefore be considered as an alternative treatment option to microsurgery for this type of aneurysm.

Implementation of computer simulation to assess flow diversion treatment outcomes: systematic review and meta-analysis

Introduction

Despite a decade of research into virtual stent deployment and the post-stenting aneurysmal hemodynamics, the hemodynamic factors which correlate with successful treatment remain inconclusive. We aimed to examine the differences in various post-treatment hemodynamic parameters between successfully and unsuccessfully treated cases, and to quantify the additional flow diversion achievable through stent compaction or insertion of a second stent.

Methods

A systematic review and meta-analysis were performed on eligible studies published from 2000 to 2019. We first classified cases according to treatment success (aneurysm occlusion) and then calculated the pooled standardized mean differences (SMD) of each available parameter to examine their association with clinical outcomes. Any additional flow diversion arising from the two common strategies for improving the stent wire density was quantified by pooling the results of such studies.

Results

We found that differences in the aneurysmal inflow rate (SMD −6.05, 95% CI −10.87 to −1.23, p=0.01) and energy loss (SMD −5.28, 95% CI −7.09 to −3.46, p<0.001) between the successfully and unsuccessfully treated groups were indicative of statistical significance, in contrast to wall shear stress (p=0.37), intra-aneurysmal average velocity (p=0.09), vortex core-line length (p=0.46), and shear rate (p=0.09). Compacting a single stent could achieve additional flow diversion comparable to that by dual-stent implantation.

Conclusions

Inflow rate and energy loss have shown promise as identifiers to discriminate between successful and unsuccessful treatment, pending future research into their diagnostic performance to establish optimal cut-off values.

Clinical and morphological risk factors for the recurrence of anterior communicating artery aneurysms after clipping or coiling

BACKGROUND

The aim of this study was to evaluate clinical and morphological factors associated with recurrence in anterior communicating artery (AcomA) aneurysms after clipping or coiling.

METHODS

We retrospectively reviewed the clinical and radiologic features of consecutive 214 patients with AcomA aneurysms treated between January 2012 and December 2016 in a single tertiary institute. Univariate and multivariate analyses were performed to identify the relationship between clinical and morphological variables and recurrence.

RESULTS

Of 214 patients, 166 were unruptured aneurysms and 109 were treated with coiling. Overall recurrence rate was 13% (28 out of 214 aneurysms) during mean 36.9 ± 18.4-month follow-up. Multivariate logistic regression analysis showed that size greater than 10 mm (OR = 5.651; 95% CI, 1.317-24.242; p = 0.020), smoking (OR = 3.474; 95% CI, 1.342-8.996; p = 0.010), coiling (OR = 2.98; 95% CI, 1.005-8.832; p = 0.049), and anterior direction of aneurysm (OR = 3.77; 95% CI, 1.12-12.66; p = 0.032) were significantly associated with recurrence of AcomA aneurysms after treatment.

CONCLUSIONS

The results of this study demonstrated that coiling, large aneurysm, anterior direction, and smoking history may be independent risk factors for the recurrence of AcomA aneurysms. Therefore, careful follow-up should be needed especially in large AcomA aneurysms with anterior direction after coiling.

Long-Term Outcomes of the WEB Device for Treatment of Wide-Neck Bifurcation Aneurysms

BACKGROUND AND PURPOSE

Treatment of wide-neck bifurcation aneurysms using endovascular therapy is still challenging even with the development of treatment devices. The purpose of this investigation was to assess the safety and efficacy of treatment with a Woven EndoBridge (WEB) device for wide-neck bifurcation aneurysms.

MATERIALS AND METHODS

All patients treated with a WEB device at our institution between May 2009 and November 2016 were retrospectively evaluated. Clinical and imaging evaluation, aneurysm occlusion status, and modified Rankin scale score were analyzed 1 day after treatment and in the short- (<6 months), mid- (<24 months), and long-term (>24 months) follow-up periods.

RESULTS

Forty-one cases of wide-neck aneurysms were analyzed in this study. Overall, 78.8% of the aneurysms had complete occlusion in the last follow-up, and 19.5% required retreatment with additional endovascular devices. A good clinical outcome (modified Rankin scale: 0-2) was obtained in 95.1% of the patients, and the overall treatment-related morbidity and mortality rates were 2.4% and 0.0%, respectively. The mean follow-up time was 15.3 ± 13.5 months.

CONCLUSIONS

The results obtained in this study suggest that treatment of wide-neck bifurcation aneurysms with a WEB device is feasible with an acceptable safety and efficacy rate.

Clipping versus coiling in unruptured anterior cerebral circulation aneurysms

Background:

Unruptured intracranial aneurysms (UIAs) are not uncommon, especially in Japan. Treatment strategy for UIAs has evolved in the past decades in Western countries with the increased use of endovascular treatment as the primary option, but in Japan, clipping still has the upper hand.

Methods:

This study retrospectively included 200 patients treated by clipping or coiling for UIAs located in the anterior cerebral circulation. Postoperative angiographic and clinical outcomes were evaluated.

Results:

Of 200 UIAs, 147 and 53 were treated by surgery and coiling, respectively. The average follow-up duration was 30.2 ± 18.8 months for clipping and 29.3 ± 17.6 months for coiling. Complete occlusion was greater in the surgery group (78.9%) than the endovascular group (18.8%). Regrowth occurred in 1.4% of the clipping group and 13.2% of the coiling group. Ischemic events were encountered in both groups; asymptomatic ones were higher in the coiling group (24.5%) than in the clipping group (2%), while symptomatic ischemic complications were equal (7.5%) in both groups. The deterioration of modified Rankin scale was detected totally in 13 UIAs (6.5%) with no statistical difference between groups. Postoperative hospital period was longer in clipping (P = 0.01).

Conclusion:

Clipping and coiling were both safe and feasible in the treatment of unruptured aneurysms. The clipping was advantageous in durability, while the rate of morbidity was lower, and hospitalization period was shorter in the coiling group. The clipping and coiling should coexist while complementing each other by understanding the advantages and disadvantages of both.

Bypass surgery of complex middle cerebral artery aneurysms-technical aspects and outcomes

BACKGROUND

The main challenge of bypass surgery of complex MCA aneurysm is not the selection of the bypass type, but the initial decision making of how to exclude the affected vessel segment from circulation. The aim of our study was to review our experience with the treatment of complex MCA aneurysms using revascularization and parent artery sacrifice techniques. Based on this, we aimed at categorizing these aneurysms according to specific surgical aspects in order to facilitate preoperative planning for these challenging surgical pathologies.

METHODS

We reviewed 50 patients with complex MCA aneurysms that were not clippable but required revascularization and parent artery sacrifice. We report the individual variations of surgical techniques, highlight the technical aspects, and categorize the aneurysms based on their location and orientation.

RESULTS

Of the 50 aneurysms, 56% were giant, 16% large, and 28% < 10 mm, but fusiform. Fourteen percent were previously treated endovascular. Four percent presented with SAH. Ten percent were prebifurcational, 60% involved the bifurcation, and 30% were postbifurcational. Both parent artery sacrifice and bypass strategies were tailored to the individual localization and anatomical relationship of the aneurysm and inflow/outflow arteries (38% proximal inflow occlusion, 42% aneurysm trapping, 20% distal outflow occlusion; 14% STA-MCA bypass, 48% interposition graft, 36%, combined/complex revascularization with reimplantation/in situ techniques). Good outcome (mRS 0-2) rates at discharge and at follow-up were 64% and 84%. Based on our analysis of individual cases, we categorized complex MCA aneurysms into six types and provide individual recommendations for their surgical exploration and treatment by revascularization and parent artery sacrifice.

CONCLUSION

Complex MCA aneurysms are among the most challenging vascular lesions and afford highly individualized treatment strategies. Revascularization and parent artery sacrifice provide durable results that are superior to the natural history. Our classification provides a tool for planning and pre-surgical assessment of the intraoperative anatomy of complex MCA aneurysms, helping to assume possible pitfalls.

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.

Endovascular treatment of middle cerebral artery aneurysms: A single center experience with a focus on thromboembolic complications

Background Endovascular treatment of middle cerebral artery (MCA) aneurysms has traditionally been considered difficult due to complex branching patterns, frequent involvement of parent vessels within the aneurysm neck, and a high incidence of thromboembolic complications. Methods The cases of 93 MCA aneurysms treated with endovascular intervention at our institution between 2003 and 2015 were retrospectively reviewed. Demographic, clinical, and radiographic variables were recorded and analyzed. Results Immediate complete or near-complete occlusion was achieved in 81 (90%) cases. At the longest follow up of 6 months or greater, 83.3% of the aneurysms were stable-to-improved in the Raymond occlusion classification, 8.3% were found to have minor recanalization not requiring retreatment, and 8.3% required retreatment due to significant recanalization. Thromboembolic events occurred in 18 (19.3%) of cases, but only 1 resulted in permanent vessel occlusion and only 1 resulted in permanent neurologic impairment. Thrombus was resolved with intra-arterial thrombolysis or mechanical thrombectomy in 17 of the 18 cases. There were only two cases resulting in morbidity (2.15%). There was no statistically significant correlation between aneurysm location, size, morphology, or use of adjuvant device with radiographic outcome or thromboembolic event. Conclusions While the rate of thromboembolic events in our series was 19%, the overall morbidity was only 2%. This highlights the fact that even complex MCA aneurysms can safely and effectively be treated by endovascular means with or without the use of balloon or stent assistance, as long as the interventionalist is astutely aware of the possibility of thrombus formation and acts accordingly with thrombolytic therapy when necessary.

Medicare expenditures for elderly patients undergoing surgical clipping or endovascular intervention for subarachnoid hemorrhage

OBJECTIVE The impact of treatment method-surgical clipping or endovascular coiling-on the cost of care for patients with aneurysmal subarachnoid hemorrhage (SAH) is debated. Here, the authors investigated the association between treatment method and long-term Medicare expenditures in elderly patients with aneurysmal SAH. METHODS The authors performed a cohort study of 100% of the Medicare fee-for-service claims data for elderly patients who had undergone treatment for ruptured cerebral aneurysms in the period from 2007 to 2012. To control for measured confounding, the authors used propensity score-adjusted multivariable regression analysis with mixed effects to account for clustering at the hospital referral region (HRR) level. An instrumental variable (regional rates of coiling) analysis was used to control for unmeasured confounding by creating pseudo-randomization on the treatment method. RESULTS During the study period, 3210 patients underwent treatment for ruptured cerebral aneurysms and met the inclusion criteria. Of these patients, 1206 (37.6%) had surgical clipping and 2004 (62.4%) had endovascular coiling. The median total Medicare expenditures in the 1st year after admission for SAH were $113,000 (IQR $77,500-$182,000) for surgical clipping and $103,000 (IQR $72,900-$159,000) for endovascular coiling. When the authors adjusted for unmeasured confounders by using an instrumental variable analysis, clipping was associated with increased 1-year Medicare expenditures by $19,577 (95% CI $4492-$34,663). CONCLUSIONS In a cohort of Medicare patients with aneurysmal SAH, after controlling for unmeasured confounding, surgical clipping was associated with increased 1-year expenditures in comparison with endovascular coiling.

Comparison of clipping and coiling in elderly patients with unruptured cerebral aneurysms

OBJECTIVE The comparative effectiveness of the 2 treatment options-surgical clipping and endovascular coiling-for unruptured cerebral aneurysms remains an issue of debate and has not been studied in clinical trials. The authors investigated the association between treatment method for unruptured cerebral aneurysms and outcomes in elderly patients. METHODS The authors performed a cohort study of 100% of Medicare fee-for-service claims data for elderly patients who had treatment for unruptured cerebral aneurysms between 2007 and 2012. To control for measured confounding, the authors used propensity score conditioning and inverse probability weighting with mixed effects to account for clustering at the level of the hospital referral region (HRR). An instrumental variable (regional rates of coiling) analysis was used to control for unmeasured confounding and to create pseudo-randomization on the treatment method. RESULTS During the study period, 8705 patients underwent treatment for unruptured cerebral aneurysms and met the study inclusion criteria. Of these patients, 2585 (29.7%) had surgical clipping and 6120 (70.3%) had endovascular coiling. Instrumental variable analysis demonstrated no difference between coiling and clipping in 1-year postoperative mortality (OR 1.25, 95% CI 0.68-2.31) or 90-day readmission rate (OR 1.04, 95% CI 0.66-1.62). However, clipping was associated with a greater likelihood of discharge to rehabilitation (OR 6.39, 95% CI 3.85-10.59) and 3.6 days longer length of stay (LOS; 95% CI 2.90-4.71). The same associations were present in propensity score-adjusted and inverse probability-weighted models. CONCLUSIONS In a cohort of Medicare patients, there was no difference in mortality and the readmission rate between clipping and coiling of unruptured cerebral aneurysms. Clipping was associated with a higher rate of discharge to a rehabilitation facility and a longer LOS.

Medicare expenditures for elderly patients undergoing surgical clipping or endovascular intervention for unruptured cerebral aneurysms

BACKGROUND

The cost difference between the two treatment options (surgical clipping and endovascular therapy) for unruptured cerebral aneurysms remains an issue of debate. We investigated the association between treatment method for unruptured cerebral aneurysms and Medicare expenditures in elderly patients.

METHODS

We performed a cohort study of 100% Medicare fee-for-service claims data for elderly patients who underwent treatment for unruptured cerebral aneurysms from 2007 to 2012. In order to control for measured confounding we used multivariable regression analysis with mixed effects to account for clustering at the Hospital Referral Region (HRR) level. An instrumental variable (regional rates of endovascular treatment) analysis was used to control for unmeasured confounding by creating pseudo-randomization on the treatment method.

RESULTS

During the study period 8705 patients underwent treatment for unruptured cerebral aneurysms and met the inclusion criteria. Of these, 2585 (29.7%) had surgical clipping and 6120 (70.3%) had endovascular treatment. The median total Medicare expenditures in the first year after the admission for the procedure were $46 800 (IQR $31 000-$74 400) for surgical clipping and $48 100 (IQR $34 500-$73 900) for endovascular therapy. When we adjusted for unmeasured confounders, using an instrumental variable analysis, clipping was associated with increased 7-day Medicare expenditures by $3527 (95% CI $972 to $5736) and increased 1-year Medicare expenditures by $15 984 (95% CI $9017 to $22 951).

CONCLUSIONS

In a cohort of Medicare patients, after controlling for unmeasured confounding, we demonstrated that surgical clipping of unruptured cerebral aneurysms was associated with increased 1-year expenditures compared with endovascular treatment.