Cost-Effectiveness Analysis of Endovascular Coiling versus Neurosurgical Clipping for Intracranial Aneurysms in Republic of Korea

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.

Risk Factor Analysis of Complications and Mortality Following Coil Procedures in Patients with Intracranial Unruptured Aneurysms Using a Nationwide Health Insurance Database

(1) Background: Unruptured intracranial aneurysm (UIA) occurs in 1-2% of the population and is being increasingly detected. Patients with UIA are treated with close observation, endovascular coiling or surgical clipping. The proportion of endovascular coiling has been rising. However, complications such as cerebral infarction (CI), intracranial hemorrhage (ICRH), and death remain crucial issues after coil treatment. (2) Methods: We analyzed the incidence and risk factors of complications after the use of coil in patients with UIA based on the patients' characteristics. We utilized the Health Insurance Review and Assessment (HIRA) database. Patients treated with coils for UIA between 1 January 2015 and 1 December 2021 were retrospectively analyzed. (3) Results: Of the total 35,140 patients, 1062 developed ICRH, of whom 87 died, with a mortality rate of 8.2%. Meanwhile, 749 patients developed CI, of whom 29 died, with a mortality rate of 3.9%. The overall mortality rate was 1.8%. In a univariate analysis of the risk factors, older age, males, a higher Charlson Comorbidity Index (CCI) score, and diabetes increase the risk of CI. Meanwhile, males with higher CCI scores and hemiplegia or paraplegia show increased ICRH risk. Older age, males and metastatic solid tumors relate to increased mortality risk. (4) Conclusions: This study is significant in that the complications based on the patient's underlying medical condition were analyzed.

Microsurgical Clipping of Unruptured Anterior Circulation Aneurysms-A Global Multicenter Investigation of Perioperative Outcomes

BACKGROUND AND OBJECTIVES

Microsurgical aneurysm repair by clipping continues to be highly important despite increasing endovascular treatment options, especially because of inferior occlusion rates. This study aimed to present current global microsurgical treatment practices and to identify risk factors for complications and neurological deterioration after clipping of unruptured anterior circulation aneurysms.

METHODS

Fifteen centers from 4 continents participated in this retrospective cohort study. Consecutive patients who underwent elective microsurgical clipping of untreated unruptured intracranial aneurysm between January 2016 and December 2020 were included. Posterior circulation aneurysms were excluded. Outcome parameters were postsurgical complications and neurological deterioration (defined as decline on the modified Rankin Scale) at discharge and during follow-up. Multivariate regression analyses were performed adjusting for all described patient characteristics.

RESULTS

Among a total of 2192 patients with anterior circulation aneurysm, complete occlusion of the treated aneurysm was achieved in 2089 (95.3%) patients at discharge. The occlusion rate remained stable (94.7%) during follow-up. Regression analysis identified hypertension (P < .02), aneurysm diameter (P < .001), neck diameter (P < .05), calcification (P < .01), and morphology (P = .002) as preexisting risk factors for postsurgical complications and neurological deterioration at discharge. Furthermore, intraoperative aneurysm rupture (odds ratio 2.863 [CI 1.606-5.104]; P < .01) and simultaneous clipping of more than 1 aneurysm (odds ratio 1.738 [CI 1.186-2.545]; P < .01) were shown to be associated with an increased risk of postsurgical complications. Yet, none of the surgical-related parameters had an impact on neurological deterioration. Analyzing volume-outcome relationship revealed comparable complication rates (P = .61) among all 15 participating centers.

CONCLUSION

Our international, multicenter analysis presents current microsurgical treatment practices in patients with anterior circulation aneurysms and identifies preexisting and surgery-related risk factors for postoperative complications and neurological deterioration. These findings may assist in decision-making for the optimal therapeutic regimen of unruptured anterior circulation aneurysms.

Surgical Aneurysm Repair of Aneurysmal Subarachnoid Hemorrhage in Sub-Saharan Africa: The State of Training and Management

BACKGROUND

In a resource-limited setting such as sub-Saharan African countries, neurosurgeons need training and fellowship for surgical repair of aneurysmal subarachnoid hemorrhage (aSAH). Surgical repair of ruptured aneurysms costs less and requires less instrumentation compared with endovascular procedures. The purpose of this study is to evaluate the state of training and management of aSAH in sub-Saharan Africa training centers.

METHODS

An e-survey was sent as a Google Form to neurosurgeons and neurosurgical trainees in neurosurgery training centers in sub-Saharan Africa; responses were accepted from September 9 to October 23, 2022. Statistical analysis was performed using Microsoft Excel and JAMOVI 3.2.

RESULTS

All 44 centers from 17 countries responded. Most of the respondents were neurosurgery residents (n = 30; 68.18%). The level of training on clipping was basic after completing the residency program (n = 18; 40.91%). Twenty respondents (45.45%) identified that fellowships on aneurysmal clipping and endovascular treatment are offered abroad. Thirteen participants (29.55%) indicated that endovascular treatment is available at their institutions. The most common challenges with lack of training for neurosurgical aneurysm clipping were scarce scholarship and collaboration with training centers from high-income countries (n = 33; 75%). The availability of intensive care unit beds also contributed to the presence of neurosurgical training of aneurysm clipping (12.1 ± 3.67 vs. 9.29 ± 5.82; P = 0.05).

CONCLUSIONS

In sub-Saharan African countries, the lack of collaborations with high-income countries for training through fellowships of young neurosurgeons for aneurysm repair seems to be the most important challenge that should be overcome.

Endovascular treatment and neurosurgical clipping in subarachnoid hemorrhage: a systematic review of economic evaluations

INTRODUCTION

There are two treatment modalities for aneurysmal subarachnoid hemorrhage: endovascular treatment (EVT) and neurosurgical clipping. Results of economic evaluations are needed to gain insight into the relationship between clinical effectiveness and costs of these treatment modalities. This important information can inform both clinical decision-making processes and policymakers in facilitating Value-Based Healthcare.

EVIDENCE ACQUISITION

Databases (PubMed, Embase, Cochrane Library, the Centre for Reviews and Dissemination, EBSCO, and Web of Science) were searched for studies published until October 2020 that had performed economic evaluations in aneurysmal subarachnoid hemorrhage patients by comparing EVT with neurosurgical clipping. The quality of reporting and methodology of these evaluations was assessed using the associated instruments (i.e. CHEERS statement and CHEC-list, respectively).

EVIDENCE SYNTHESIS

A total of 6 studies met the inclusion criteria. All included studies reported both effects and costs, however five did not relate effects to costs. Only one study related effects directly to costs, thus conducted a full economic evaluation. The reporting quality scored 81% and the methodological quality scored 30%.

CONCLUSIONS

The quality of published cost-effectiveness studies on the treatment of aneurysmal subarachnoid hemorrhage is poor. Six studies reported both outcomes and costs, however only one study performed a full economic evaluation comparing EVT to neurosurgical clipping. Although the reporting quality was sufficient, the methodological quality was poor. Further research that relates health-related quality of life measures to costs of EVT and neurosurgical clipping is required - specifically focusing on both reporting and methodological quality. Different subgroup analyses and modeling could also enhance the findings.

A cost-utility analysis comparing endovascular coiling to neurosurgical clipping in the treatment of aneurysmal subarachnoid haemorrhage

Endovascular coiling (EC) has been identified in systematic reviews and meta-analyses to produce more favourable clinical outcomes in comparison to neurosurgical clipping (NC) when surgically treating a subarachnoid haemorrhage from a ruptured aneurysm. Cost-effectiveness analyses between both interventions have been done, but no cost-utility analysis has yet been published. This systematic review aims to perform an economic analysis of the relative utility outcomes and costs from both treatments in the UK. A cost-utility analysis was performed from the perspective of the National Health Service (NHS), over a 1-year analytic horizon. Outcomes were obtained from the randomised International Subarachnoid Aneurysm Trial (ISAT) and measured in terms of the patient's modified Rankin scale (mRS) grade, a 6-point disability scale that aims to quantify a patient's functional outcome following a stroke. The mRS score was weighted against the Euro-QoL 5-dimension (EQ-5D), with each state assigned a weighted utility value which was then converted into quality-adjusted life years (QALYs). A sensitivity analysis using different utility dimensions was performed to identify any variation in incremental cost-effectiveness ratio (ICER) if different input variables were used. Costs were measured in pounds sterling (£) and discounted by 3.5% to 2020/2021 prices. The cost-utility analysis showed an ICER of - £144,004 incurred for every QALY gained when EC was utilised over NC. At NICE's upper willingness-to-pay (WTP) threshold of £30,000, EC offered a monetary net benefit (MNB) of £7934.63 and health net benefit (HNB) of 0.264 higher than NC. At NICE's lower WTP threshold of £20,000, EC offered an MNB of £7478.63 and HNB of 0.374 higher than NC. EC was found to be more 'cost-effective' than NC, with an ICER in the bottom right quadrant of the cost-effectiveness plane-indicating that it offers greater benefits at lower costs. This is supported by the ICER being below the NICE's threshold of £20,000-£30,000 per QALY, and both MNB and HNB having positive values (> 0).

Knowledge framework and emerging trends in intracranial aneurysm magnetic resonance angiography: a scientometric analysis from 2004 to 2020

Background

As magnetic resonance angiography (MRA) has been increasingly used in the follow-up of intracranial aneurysms (IAs) as a non-invasive technique, the knowledge framework and areas of research interest in intracranial aneurysms magnetic resonance angiography (IAMRA) change approximately every 10 years. However, few studies have quantitatively analyzed the published literature in this field. In the present study, we used scientometrics to survey the knowledge field, development trends, and research focus of IAMRA with the aim of providing a reference for further study.

Methods

We collected articles on IAMRA published from 2004 (Jan 1, 2004) to 2020 (May 24, 2020). Web of Science Core Collection databases (WoSCCd) including the Science Citation Index Expanded were searched. An experienced staff member from the Department of Radiology at Southern Medical University, assisted in screening articles for relevant articles. We used ArcGIS (a mapping and location analytics platform) to perform geographic visualization. Excel 2016 was used to analyze the literature data, including number of publications, impact factor (IF), and publication year. CiteSpace V was used to conduct a series of literature feature clustering, including author co-citation analysis, reference co-citation analysis (RCA), and burst keywords analysis.

Results

A total of 1,272 articles on IAMRA published between 2004 and 2020 were included. Of 257 journals, American Journal of Neuroradiology (IF 2018: 3.256) published the most IAMRA articles (109 publications, 8.57%), followed by Journal of Neurosurgery (IF 2018: 4.131, 51 publications, 4.16%), and Neuroradiology (IF 2018: 2.504, 51 publications, 4.01%). Of 56 countries, the USA published the most, with 347 articles [27.28%, IF: 3.14 (average IF of all journals in the country)], followed by Japan (242 articles, 19.03%, IF: 2.38), Germany (135 articles, 10.61%, IF: 3.21), and China (101 articles, 7.94%, IF: 2.86). A total of 1387 institutions published articles, with the Mayo Clinic publishing the most (33 articles, 2.59%), followed by Shanghai Jiao Tong University (25 article, 1.97%), Seoul National University (23 articles, 1.81%), and University Medical Center Utrecht (19 articles, 1.49%). Of 399 authors, Rinkel ranked first with 19 articles, followed by Li MH (18 articles), Uchino A (15 articles), and Saito N (13 articles). Cluster RCA showed that the first cluster was "#0 growth", followed by "#1 Guglielmi detachable coils". Timeline views showed that the time span of "#0 growth" was the closest to today. The modularity value was 0.6971, and the mean silhouette value was 0.5477. According to the burst keyword analysis, "risk factors associated to rupture" was the topic with the strongest burst since 2017. Studies conducted in several countries suggested that age is inversely related to the risk of rupture, which implies the importance of MRA follow-up for patients of different age.

Conclusions

From 2004 to 2020, the number of published IAMRA-related articles gradually increased. The USA and Western Europe lead in the field, with a concentration of cutting-edge talents and high-level scientific research institutions. A synthesis of the clustering results of RCA and burst keyword analysis indicated that unruptured IA growth, stent-assisted coil embolization, and risk factors associated to rupture were the current hotspots in IAMRA research.

Outcomes of treatment modalities for ruptured intracranial aneurysms based on age - A meta-analysis

BACKGROUND

Data comparing the effect of age on outcomes of patients who underwent either endovascular coiling (EVC) or neurosurgical clipping (NSC) for ruptured intracranial aneurysms remains limited.

OBJECTIVE

To better elucidate the preferred intervention for ruptured aneurysm management by presenting the results of our systematic review of the literature that evaluated the potential advantages of the two interventions between different age groups.

METHODS

Systematic review of PubMed and Embase was performed (2002 - June 10, 2019) following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2013 guidelines. Median ages of EVC and NSC cohorts were 54 and 56, respectively. Ages below the median were used in our "younger" cohort; ages above the median were used in our "older" cohort.

RESULTS

We reviewed 13 studies on 7,137 patients. In the younger cohort, there were 2840 (EVC: 1412, NSC: 1428) patients. In the older cohort, there were 4297 (EVC: 2552, NSC: 1745) patients. Overall, there was a significant difference in functionality between EVC (77.70%) and NSC (69.23%) (OR=1.69; 95% C.I.: 1.10-2.60, p = 0.0212). In our younger cohort, functionality was significantly different between EVC (77%) and NSC (69%) (OR=1.54; 95% C.I.: 1.29-1.84, p < 0.001). For the older cohort, there was no significant difference in functionality, complications, or efficacy.

CONCLUSIONS

We have highlighted the importance of considering age prior to deciding which intervention is most appropriate for ruptured aneurysms, with higher morbidity and mortality with NSC versus EVC in the younger population.

[Endovascular Treatment of Cerebral Aneurysms: Technical Options in Coil Embolization]

Since the endosaccular coil embolization technique was introduced as an alternative for treating selected patients with aneurysms, it has become a mainstay of treatment for cerebral aneurysms. In lesions with a neck larger than the aneurysmal body, an irregular shape, or arterial branches incorporated within the sac, endovascular treatment using detachable coils are traditionally contraindicated because of technical difficulties. Coil embolization has evolved as a result of both the development of related devices and the introduction of technical improvements using various devices. Use of various technical and device options can make endovascular treatment of cerebral aneurysms safer and can widen the treatment indications. Various technical options, including the technical modification of device-assisted techniques, will be presented, and the related practical points will be discussed in this issue.

Endovascular coiling versus surgical clipping for the treatment of unruptured cerebral aneurysms: Direct comparison of procedure-related complications

BACKGROUND

Endovascular coiling and surgical clipping are routinely used to treat unruptured cerebral aneurysms (UCAs). However, the evidence to support the efficacy of these approaches is limited. We aimed to analyze the efficacy of endovascular coiling compared with surgical clipping in patients with UCAs.

METHOD

A systematic search of 4 databases was conducted to identify comparative articles involving endovascular coiling and surgical clipping in patients with UCAs. We conducted a meta-analysis using the random-effects model when I> 50%. Otherwise, a meta-analysis using the fixed-effects model was performed.

RESULTS

Our results showed that endovascular coiling was associated with a shorter length of stay (WMD: -4.14, 95% CI: (-5.75, -2.531), P < .001) and a lower incidence of short-term complications compared with surgical clipping (OR: 0.518; 95% CI (0.433, 0.621); P < .001), which seems to be a result of ischemia complications (OR: 0.423; 95% CI (0.317, 0.564); P < .001). However, surgical clipping showed a higher rate of complete occlusion after surgery, in both short-term (OR: 0.179, 95% CI (0.064, 0.499), P = .001) and 1-year follow-ups (OR: 0.307, 95% CI (0.146, 0.646), P = .002), and a lower rate of short-term retreatment (OR: 0.307, 95% CI (0.146, 0.646), P = .002). Meanwhile, there was no significant difference in postoperative death, bleeding, and modified Rankin Scale (mRS) > 2 between the 2 groups.

CONCLUSIONS

The latest evidence illustrates that surgical clipping resulted in lower retreatment rates and was associated with a higher incidence of complete occlusion, while endovascular coiling was associated with shorter LOS and a lower rate of complications, especially ischemia.

Cost of hospitalization for aneurysmal subarachnoid hemorrhage in the United States

OBJECTIVE

Recent large-scale studies describing hospitalization cost trends secondary to aneurysmal subarachnoid hemorrhage (aSAH) in the United States are lacking. We sought to discover the impact of aSAH-related factors upon its hospitalization cost.

PATIENTS AND METHODS

Patients with a primary diagnosis of aSAH were selected utilizing the National Inpatient Sample. Regression analyses were used to evaluate the impact of aSAH-related factors on hospitalization costs.

RESULTS

From 2002-2014, 22,831 cases of aSAH were identified. The inflation-adjusted mean cost of hospitalization was $82,514 (standard deviation ± $54,983). The proportion of males was lower (31%), but a higher cost of $3385 (± $685; p < .001) remained compared to females. Median length of hospitalization was 16 days (interquartile range 11-23) and each day increase in hospitalization was associated with a cost increase of $3228 (± $19; p < .001). There was no difference in cost between patients undergoing aneurysmal coiling or clipping. When compared to patients < 40 years old, the increase in cost for patients 40-59 years old was $3829 (± $914; p < .001), and $4573 (± $1033; p < .001) for patients 60-79 years old; however, for patients ≥ 80 years old, there was a decrease in cost of $8124 (± $1722; p < .001). Several central nervous system complications were also associated with increased cost.

CONCLUSION

aSAH is a significant financial burden on the United States healthcare system. We were able to identify many important factors associated with higher costs, and these results may help us understand resource utilization and develop future cost-reduction strategies.

Cost Analysis of Endovascular Coiling and Surgical Clipping for the Treatment of Ruptured Intracranial Aneurysms

BACKGROUND

Cost-effectiveness analyses for the treatment of aneurysmal subarachnoid hemorrhage are necessary to determine health policy, treatment guidelines, and screening protocols for cerebral aneurysms. To perform these modeling studies, detailed cost data are necessary and are currently lacking.

OBJECTIVE

The goal of this study was to determine detailed inpatient cost of aneurysmal subarachnoid hemorrhage.

METHODS

A retrospective review of our ruptured subarachnoid hemorrhage database was performed to identify consecutive patients between January 2013 and December 2015. Patients were searched by International Classification of Disease 9 diagnosis and procedure codes. Patient demographics and clinical characteristics were acquired. The cost breakdown was compiled into a comprehensive itemized list encompassing all aspects of hospitalization. A mean cost based on resource used per patient was obtained.

RESULTS

There were 269 patients treated, 209 were coiled and 60 were clipped. Mean age in the clipping group was 49 years and 55 years in the coil group (P = 0.006). Other patient demographics and clinical characteristics were found to be statistically similar for both groups. Total cost per patient for treatment and hospital stay was $74,192 for clipping and $85,553 for coiling (P = 0.06). Cost amplified with increasing Hunt and Hess grade in both clipping and coiling groups.

CONCLUSIONS

The detailed cost information reported in this article can be used to help establish appropriate, standardized costs nationally by improving transparency. It can also help provide critical information necessary to develop cost-effective treatment algorithms and screening protocols.

Comparative Cost Analysis for the Surgical and Endovascular Treatment of Ruptured Intracranial Aneurysms in Taiwan: A Nationwide Population-Based Cohort Study

OBJECTIVE

Using a database that enabled longitudinal follow-up, we assessed the cost, outcome, complications, and readmission rate of ruptured cerebral aneurysms repaired by surgical clipping and endovascular coiling.

METHODS

This study was a retrospective review of data from a series of patients who underwent surgical clipping or endovascular coiling of ruptured cerebral aneurysms between 1996 and 2013. The medical records and hospital cost data were all examined.

RESULTS

A total of 7690 and 1380 cases were treated with clipping and coiling, respectively. Patients treated with clipping had more comorbidities and were older. The average total cost for endovascular coiling was $13,974.3, whereas the average total cost for surgical clipping was $16,581.7. Perioperative (30-day) mortality was 10.7% in patients with coiled aneurysms, compared with 12.6% in those with clipped aneurysms (P = 0.045). After 1 year of follow-up, clipping was associated with a significantly longer length of hospital stay (P < 0.001) and significantly higher total hospital costs (P < 0.001).

CONCLUSIONS

In Taiwan, the total hospital costs for the surgical clipping of cerebral aneurysms were higher than for endovascular coiling, and the surgical results were associated with significant complications. We suggest that the indications for coiling might need to be expanded from the current standards dictated by the guidelines in Taiwan.

Total Hospital Costs and Length of Stay of Endovascular Coiling Versus Neurosurgical Clipping for Unruptured Intracranial Aneurysms: Systematic Review and Meta-Analysis

OBJECTIVE

Comparison of feasibility and safety between endovascular coiling versus neurosurgical clipping for the management of unruptured intracranial aneurysms (UIAs) has been incrementally reported. However, economic comparison has been rarely reported. This meta-analysis aims at qualitatively and quantitatively analyzing the difference of hospital costs and length of stay between endovascular versus neurosurgical treatment in UIA.

METHODS

MEDLINE, the Cochrane database, EMBASE, and Web of Science database were searched for cohort studies describing economic hospital cost or length of stay in patients with UIA. Two authors independently assessed study eligibility and rated quality using the Newcastle Ottawa Scale. Ravmen 5.2 was used to perform forest plot analysis.

RESULTS

Nine studies describing 24,856 UIAs treated with neurosurgical clipping and 31,309 UIAs treated with endovascular coiling were included. Meta-analysis revealed that the total hospital costs (THCs) were similar between coiling and clipping in UIA patients (standard mean difference [SMD]: -0.33, 95% confidence interval: -0.68 to 0.02, I² = 99%, P = 0.07). Subgroup analysis showed that THCs of coiling were significantly lower than clipping in the United States but opposite in South Korea. One-year medical costs of coiling were similar in both groups (SMD: -0.04, 95% CI: -0.08 to 0.00, I² = 0%, P = 0.07). In addition, the length of stay of coiling were significantly shorter than that of clipping (SMD: 0.69, 95% CI: 0.56-0.81, I² = 95%, P < 0.001).

CONCLUSION

Generally, no significant difference in THCs and 1-year medical costs between coiling versus clipping in UIAs was observed. However, the length of stay of endovascular coiling was much shorter than neurosurgical clipping and decreased over time.

A Systematic Review and Meta-Analysis on Economic Comparison Between Endovascular Coiling Versus Neurosurgical Clipping for Ruptured Intracranial Aneurysms

OBJECTIVE

Healthcare expenditures and cost reduction have been under critical surveillance in all countries and are critical for policymakers. This review aims at qualitatively and quantitatively analyzing the difference of hospital costs and length of stay between endovascular coiling versus neurosurgical clipping in ruptured intracranial aneurysms (RAs).

METHODS

MEDLINE, the Cochrane database, Embase, and the Web of Science database were searched and evaluated independently by 2 authors according to the Newcastle-Ottawa Scale for cohort studies describing economic hospital cost or length of stay in patients with RAs.

RESULTS

A total of 8 studies were included, describing 24,219 RAs treated with neurosurgical clipping and 24,962 RAs with endovascular coiling. Meta-analysis revealed that the total hospital costs (THCs) were similar between coiling versus clipping in RAs (standard mean difference [SMD], -0.05; 95% confidence interval [CI], -0.12 to 0.22; I² = 99%; P = 0.50). Subgroup analysis showed that THCs of clipping and coiling were similar in ruptured aneurysms in the United States. However, in South Korea, the THCs of coiling were significantly higher than clipping. In the long run, 1-year medical costs of endovascular treatment were significantly lower than that of clipping in RAs (SMD, 0.15; 95% CI, 0.05-0.25; I² = 66%; P = 0.005). In addition, the length of stay of coiled patients was significantly shorter than clipped patients (SMD, 0.29; 95% CI, 0.13-0.45; I² = 96%; P < 0.001).

CONCLUSIONS

Medical costs were region-specified. In the United States, total hospital costs and 1-year medical costs were similar in RA patients treated with endovascular coiling and neurosurgical clipping. However, in countries like South Korea and China, coiling was more expensive. The length of stay was much shorter in coiled patients in all countries.

Development of New Endovascular Devices for Aneurysm Treatment

Since the first use of the Guglielmi detachable coil system for cerebral aneurysm embolization in 1990, various endovascular methods have been developed to treat large numbers of aneurysms. The main strategic and technical modifications introduced to date include balloon-assisted coil embolization, stent-assisted coil embolization, flow diverters, and flow disrupters. The development and introduction of such devices have been so persistent and rapid that new devices are being approved worldwide even before the earlier ones become available in some countries. However, even if some patient populations may possibly benefit from earlier introduction of new devices, the approval authorities should balance the available evidence of the safety and effectiveness of novel devices. This review aims to provide an overview of the recent innovations in endovascular treatment of cerebral aneurysms and a brief review of market access policies and regulations for importing high-risk medical devices, such as those used for endovascular aneurysm management, which correspond to class III devices, as defined by the U.S. Food and Drug Administration. We focus on the current situation in Korea and compare it with that in other Asian countries, such as China and Japan.

Monthly variations in aneurysmal subarachnoid hemorrhage incidence and mortality: Correlation with weather and pollution

BACKGROUND AND PURPOSE

Although the effect of weather and air pollution on the occurrence of subarachnoid hemorrhage (SAH) has been investigated, results have remained inconsistent. The present study aimed to determine the seasonality of aneurysmal subarachnoid hemorrhage occurrence and mortality.

METHODS

We used the National Inpatient Sample database to evaluate the effect of meteorological factors and air pollutants on patients with subarachnoid hemorrhage in Korea between 2011 and 2014. Monthly variations in SAH occurrence and mortality were analyzed using locally weighted scatter plot smoothing curves. Multivariate Poisson generalized linear regression models were used to evaluate potential independent meteorological and pollutant variables associated with SAH occurrence and mortality.

RESULTS

In total, 21,407 patients who underwent clip or coil treatment owing to aneurysmal SAH in Korea from January 1, 2011, to December 31, 2014, were included. The crude incidence rate of SAH in Korea was 10.5 per 100,000 people per year. An approximately 0.5% lower risk of SAH was observed per 1°C increase in mean monthly temperature (relative risk, 0.995; 95% confidence interval [CI], 0.992-0.997; p < 0.001), while an approximately 2.3% higher risk of SAH was observed per 1°C increase in mean monthly diurnal temperature.

CONCLUSIONS

We showed distinct patterns of seasonal and monthly variation in the occurrence and mortality of SAH. Our findings suggest that meteorological factors may play an important role in monthly variations in the occurrence of aneurysmal SAH.

[Postoperative changes of Th17/Treg balance in patients with intracranial aneurysm rupture]

OBJECTIVE

To observe the dynamic changes of Th17/Treg balance in patients following surgical intervention for intracranial aneurysm rupture.

METHODS

The percentage of Th cells and the intracellular IL-17 level, Treg cell percentage and transforming growth factor -β1 (TGF-β1) levels were examined in 73 patients with rupture of aneurysms before and at 24 h, 72 h and 1 week after operation, with 62 patients with unruptured aneurysms and 65 healthy volunteers as the control. The correlations among the immune cells, cytokines and clinical characteristics of the patients (NIHSS, ADL and hospitalization stay) were analyzed.

RESULTS

Th17 percentage and intracellular IL-17 levels were significantly higher in the patients with ruptured and unruptured aneurysms than in the healthy volunteers, and were significantly higher in patients with ruptured aneurysms than in those with unruptured aneurysms. Treg cell percentage and TGF-β1 level were significantly lower in patients with aneurysms than in the healthy volunteers, and were lower in patients with ruptured aneurysms than in those with uruptured aneurysms (P<0.05). Patients with intracranial aneurysm rupture showed significantly increased Th17 cell percentage and IL-17 level but significantly lowered Treg cell percentage and TGF-β1 at 24 h following the surgery (P<0.05); these changes were reversed significantly at 72 h and 1 week after the surgery. Th17 cell percentage and IL-17 level were positively correlated with NIHSS and the length of postoperative hospital stay but inversely correlated with ADL; Treg cell percentage and TGF-β1 were inversely correlated with NIHSS and hospital stay but positively with ADL (P<0.05).

CONCLUSION

In patients with intracranial aneurysms, the systemic immune inflammatory response is highlighted by excessive Th17 cells and insufficient Treg cells, which are closely related with the outcomes of the patients following surgical intervention. Evaluation of Th17/Treg balance and the cytokine levels can help to assess the prognosis of patients with aneurysm rupture.