New York State: Comparison of Treatment Outcomes for Unruptured Cerebral Aneurysms Using an Instrumental Variable Analysis

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.

Causes, Predictors, and Trends of Unplanned Readmissions after Elective Endovascular Embolization of Cerebral Aneurysms

BACKGROUND

30- and 90-day readmissions (dRA) are being increasingly scrutinized as quality metrics for hospital and provider performances. Little information regarding risk factors for readmission after elective endovascular treatment (EVT) of an unruptured cerebral aneurysm (UCA) is available.

METHODS

The Nationwide Readmissions Database was used to identify patients who underwent elective endovascular embolization of an unruptured aneurysm between 2010 and 2014. The primary outcomes of interest were unplanned readmissions occurring within 30 or 90 days of discharge. Binary logistic regressions were used to identify variables related to patients' demographics, comorbidities, and index hospital admission that were associated with 30dRA and 90dRA.

RESULTS

A total of 8588 patients met the inclusion criteria for 30dRA analysis and 7289 patients were eligible for 90dRA analysis. The 5-year 30dRA and 90dRA readmission rates were 7.1% and 13.5%, respectively. The annual incidences of 30dRAs and 90dRAs between 2010 and 2014 decreased significantly (pooled odds ratio (OR) for 30dRA: .874, 95% confidence interval (CI) .765-.998; pooled OR for 90dRA: .841, 95% CI .755-.938). Patients in higher income quartiles experienced decreased odds of 30dRA and 90dRA. Nonroutine disposition following the index admission and greater comorbidity burdens were associated with higher likelihoods of both 30dRA and 90dRA. The presence of pulmonary or cardiac complications was associated with increased odds of 90dRA.

CONCLUSION

Readmission rates after elective EVT of UCAs decreased between 2010 and 2014. We identified several novel risk factors for both 30dRAs and 90dRAs that can be used to identify patients who are at highest risk of readmission.

Trends for in-hospital metrics in the treatment of intracranial aneurysms in Minas Gerais, Brazil

Background: Aneurysmal subarachnoid hemorrhage (ASAH) and unruptured aneurysm (URA) are particularly important because of the high mortality rates, and physical and cognitive impairment, which affect the economically active population. The present work aims at describing the scenario regarding in-hospital indicators related to the following therapeutic approaches: vascular microsurgery (VMS) and endovascular therapy (EVT) in the state of Minas Gerais, Brazil, in order to gather information to construct hypotheses and plan actions. Methods: The study has an ecological design and it is also analytical for the time trends of 2008-2014. Trends for VMS and EVT therapies and mortality are estimated using linear regression, followed by the Prais-Winsten procedure. Data were obtained through Hospital Information System (Sistema de Informações Hospitalares - SIH) of Brazilian Public Health System (Sistema Único de Saúde - SUS). Results: In 2014, 601 procedures were performed, and out of these, 373 (62%) were triggered by SAH and 228 (38%) by URA. The frequency of procedures performed in males and in females results in a ratio of 1:2 for SAH procedures and 1:3 for URA procedures. A heterogeneous distribution of therapeutic approaches was seen among the hospital studied, suggesting a technological preference, which determines the therapeutic approach. Conclusion: Technological bias was observed for aneurysm treatment in Minas Gerais's hospitals. EVT is seen to have a growing trend to detriment of VMS (β₁ = 0.024; p = 0.025), with a stable mortality for both therapeutics in both pathologies (SAH and URA). EVT has been associated with a shorter hospital stay, with higher expenses for both ASAH and URA treatment. EVT showed an inverse correlation with in-hospital fatality for ASAH treatment.

Procedural Clinical Complications, Case-Fatality Risks, and Risk Factors in Endovascular and Neurosurgical Treatment of Unruptured Intracranial Aneurysms: A Systematic Review and Meta-analysis

Importance

The risk of procedural clinical complications and the case-fatality rate (CFR) from preventive treatment of unruptured intracranial aneurysms varies between studies and may depend on treatment modality and risk factors.

Objective

To assess current procedural clinical 30-day complications and the CFR from endovascular treatment (EVT) and neurosurgical treatment (NST) of unruptured intracranial aneurysms and risk factors of clinical complications.

Data Sources

We searched PubMed, Excerpta Medica Database, and the Cochrane Database for studies published between January 1, 2011, and January 1, 2017.

Study Selection

Studies reporting on clinical complications, the CFR, and risk factors, including 50 patients or more undergoing EVT or NST for saccular unruptured intracranial aneurysms after January 1, 2000, were eligible.

Data Extraction and Synthesis

Per treatment modality, we analyzed clinical complication risk and the CFR with mixed-effects logistic regression models for dichotomous data. For studies reporting data on complication risk factors, we obtained risk ratios (RRs) or odds ratios (ORs) with 95% CIs and pooled risk estimates with weighted random-effects models.

Main Outcomes and Measures

Clinical complications within 30 days and the CFR.

Results

We included 114 studies (106 433 patients with 108 263 aneurysms). For EVT (74 studies), the pooled clinical complication risk was 4.96% (95% CI, 4.00%-6.12%), and the CFR was 0.30% (95% CI, 0.20%-0.40%). Factors associated with complications from EVT were female sex (pooled OR, 1.06 [95% CI, 1.01-1.11]), diabetes (OR, 1.81 [95% CI, 1.05-3.13]), hyperlipidemia (OR, 1.76 [95% CI, 1.3-2.37]), cardiac comorbidity (OR, 2.27 [95% CI, 1.53-3.37]), wide aneurysm neck (>4 mm or dome-to-neck ratio >1.5; OR, 1.71 [95% CI, 1.38-2.11]), posterior circulation aneurysm (OR, 1.42 [95% CI, 1.15-1.74]), stent-assisted coiling (OR, 1.82 [95% CI, 1.16-2.85]), and stenting (OR, 3.43 [95% CI, 1.45-8.09]). For NST (54 studies), the pooled complication risk was 8.34% (95% CI, 6.25%-11.10%) and the CFR was 0.10% (95% CI, 0.00%-0.20%). Factors associated with complications from NST were age (OR per year increase, 1.02 [95% CI, 1.01-1.02]), female sex (OR, 0.43 [95% CI, 0.32-0.85]), coagulopathy (OR, 2.14 [95% CI, 1.13-4.06]), use of anticoagulation (OR, 6.36 [95% CI, 2.55-15.85]), smoking (OR, 1.95 [95% CI, 1.36-2.79]), hypertension (OR, 1.45 [95% CI, 1.03-2.03]), diabetes (OR, 2.38 [95% CI, 1.54-3.67]), congestive heart failure (OR, 2.71 [95% CI, 1.57-4.69]), posterior aneurysm location (OR, 7.25 [95% CI, 3.70-14.20]), and aneurysm calcification (OR, 2.89 [95% CI, 1.35-6.18]).

Conclusions and Relevance

This study identifies risk factors for procedural complications. Large data sets with individual patient data are needed to develop and validate prediction scores for absolute complication risks and CFRs from EVT and NST modalities.

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.

Quasi-experimental study designs series-paper 5: a checklist for classifying studies evaluating the effects on health interventions-a taxonomy without labels

Objectives

The aim of the study was to extend a previously published checklist of study design features to include study designs often used by health systems researchers and economists. Our intention is to help review authors in any field to set eligibility criteria for studies to include in a systematic review that relate directly to the intrinsic strength of the studies in inferring causality. We also seek to clarify key equivalences and differences in terminology used by different research communities.

Study Design and Setting

Expert consensus meeting.

Results

The checklist comprises seven questions, each with a list of response items, addressing: clustering of an intervention as an aspect of allocation or due to the intrinsic nature of the delivery of the intervention; for whom, and when, outcome data are available; how the intervention effect was estimated; the principle underlying control for confounding; how groups were formed; the features of a study carried out after it was designed; and the variables measured before intervention.

Conclusion

The checklist clarifies the basis of credible quasi-experimental studies, reconciling different terminology used in different fields of investigation and facilitating communications across research communities. By applying the checklist, review authors' attention is also directed to the assumptions underpinning the methods for inferring causality.

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.

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.

Clinical management of unruptured intracranial aneurysm in Germany: a nationwide observational study over a 5-year period (2005-2009)

OBJECTIVES

Our aim was to provide nationwide age-standardised rates (ASR) on the usage of endovascular coiling and neurosurgical clipping for unruptured intracranial aneurysm (UIA) treatment in Germany.

SETTING

Nationwide observational study using the Diagnosis-Related-Groups (DRG) statistics for the years 2005-2009 (overall 83 million hospitalisations).

PARTICIPANTS

From 2005 to 2009, overall 39 155 hospitalisations with a diagnosis of UIA occurred in Germany.

PRIMARY OUTCOME MEASURES

Age-specific and age-standardised hospitalisation rates for UIA with the midyear population of Germany in 2007 as the standard.

RESULTS

Of the 10 221 hospitalisations with UIA during the observation period, 6098 (59.7%) and 4123 (40.3%) included coiling and clipping, respectively. Overall hospitalisation rates for UIA increased by 39.5% (95% CI 24.7% to 56.0%) and 50.4% (95% CI 39.6% to 62.1%) among men and women, respectively. In 2005, the ASR per 100 000 person years for coiling was 0.7 (95% CI 0.62 to 0.78) for men and 1.7 (95% CI 1.58 to 1.82) for women. In 2009, the ASR was 1.0 (95% CI 0.90 to 1.10) and 2.4 (95% CI 2.24 to 2.56), respectively. Similarly, the ASR for clipping in 2005 amounted to 0.6 (95% CI 0.52 to 0.68) for men and 1.1 (95% CI 1.00 to 1.20) for women. These rates increased in 2009 to 0.8 (95% CI 0.72 to 0.88) and 1.7 (95% CI 1.58 to 1.82), respectively. We observed a marked geographical variation of ASR for coiling and less pronounced for clipping. For the federal state of Saarland, the ASR for coiling was 5.64 (95% CI 4.76 to 6.52) compared with 0.68 (95% CI 0.48 to 0.88; per 100 000 person years) in Saxony-Anhalt, whereas, ASR for clipping were highest in Rhineland-Palatinate (2.48, 95% CI 2.17 to 4.75) and lowest in Saxony-Anhalt (0.52, 95% CI 0.34 to 0.70).

CONCLUSIONS

To the best of our knowledge, we presented the first representative, nationwide analysis of the clinical management of UIA in Germany. The ASR increased markedly and showed substantial geographical variation among federal states for all treatment modalities during the observation period.

Continuity of care and 30-day readmission for patients evaluated in the emergency room after cerebral aneurysm treatment

Background

The association between continuity of care and the rate of 30-day readmissions after surgical procedures continues to be debated.

Objective

To investigate the association of 30-day readmissions with evaluation in the hospital where the original procedure was performed for patients presenting to the emergency department (ED) after cerebral aneurysm treatment.

Methods

We performed a cohort study of patients with cerebral aneurysms, who were evaluated in the ED within 30 days after discharge following surgical clipping or endovascular coiling between 2009 and 2013, and were registered in the Statewide Planning and Research Cooperative System database. A propensity score adjusted model was used to control for confounding, whereas mixed effects accounted for clustering at the hospital level.

Results

Of the 452 patients presenting to the ED, 218 (48.2%) were evaluated in a different hospital from that in which the original procedure was performed (7.7% readmitted), and 234 (51.8%) were evaluated at the original hospital (18.4% readmitted). In a multivariable analysis, we showed that evaluation in the ED of the original hospital was associated with decreased rate of 30-day readmission (OR=0.41; 95% CI 0.22 to 0.78). We found similar associations in a mixed-effects logistic regression model (OR=0.46; 95% CI 0.35 to 0.84) and a propensity score adjusted model (OR=0.41; 95% CI 0.22 to 0.77). This corresponds to10 patients needing to be evaluated in the hospital at which the original procedure was performed to prevent one readmission.

Conclusions

Using a comprehensive all-payer cohort of patients in New York State, who were evaluated in the ED after cerebral aneurysm treatment, we identified an association between assessment in the hospital at which the original procedure was performed and a lower rate of 30-day readmissions. This underlines the potential importance of continuity of care for surgical patients to prevent readmission.