High Subarachnoid Hemorrhage Patient Volume Associated With Lower Mortality and Better Outcomes

Health care-associated infections after surgical treatment of ruptured intracranial aneurysms

BACKGROUND

Aneurysmal subarachnoid hemorrhage (SAH) is catastrophic, and microsurgery for ruptured intracranial aneurysms is one of the preventive modalities for rebleeding. However, patients remain at high risk of medical morbidities after surgery, one of the most important of which is health care-associated infections (HAIs). We analyzed the incidence and risk factors of HAIs, as well as their association with the outcomes after surgical treatment of ruptured aneurysms.

METHODS

We retrospectively enrolled 607 patients with SAH who had undergone surgery for intracranial aneurysms. Information was retrieved from the database using codes of the International Classification of Diseases, Ninth Revision, Clinical Modification.

RESULTS

Of the 607 patients, 203 were male and 404 were female. HAIs occurred in 113 patients, accounting for 18.6 % of the population. The independent risk factors for HAIs included age ((p = 0.035), hypertension ((p = 0.042), convulsion ((p = 0.023), external ventricular drain ((p = 0.035), ventricular shunt ((p = 0.033), and blood transfusion ((p = 0.001). The mean length of hospital stay was 25.3 ± 18.2 and 18.8 ± 15.3 days for patients with and without HAIs, respectively ((p = 0.001). The in-hospital mortality rates were 11.5 % in the HAIs group, and 14.0 % in the non-HAIs group ((p = 0.490).

CONCLUSION

HAIs are a frequent complication in patients with SAH who underwent surgery for ruptured intracranial aneurysms. The length of hospital stay is remarkably longer for patients with HAIs, and to recognize and reduce the modifiable risks should be implemented to improve the quality of patient care.

Early Intravenous Magnesium Sulfate and Its Impact on Cerebral Vasospasm as well as Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage: A Retrospective Matched Case-Control Analysis

BACKGROUND

Magnesium sulfate (MgSO4) is a potential neuroprotective agent for patients with aneurysmal subarachnoid hemorrhage (SAH). We analyzed the effect of early application of intraoperative intravenous MgSO4 and compared cerebral vasospasm (CV), delayed cerebral ischemia (DCI), and neurological outcome in 2 patient cohorts.

METHODS

A retrospective matched-pair analysis from patients at a single center in Germany was performed without (group A) and with (group B) MgSO4 application <24 hours after diagnosis. Pairs were matched according to the known risk factors for DCI and CV (age, Fisher grade, smoking, severity of SAH). Incidence of CV and DCI and neurological outcome using the modified Rankin Scale score 3 and 12 months after SAH were recorded.

RESULTS

The inclusion criteria were met by 196 patients. After risk stratification, 48 patients were included in the final analysis (age 54.2 ± 8.1 years; 30 women and 18 men) and were assigned to group A (n = 24) or group B (n = 24). CV occurred less frequently in group B (33%) than in group A (46%). Likewise, DCI was present in 13% in group B compared with 42% in group A. After 12 months, 22 patients in group B had a favorable functional outcome (modified Rankin Scale score 0-3) compared with 15 patients in group A.

CONCLUSIONS

In this study, the incidence of CV and DCI was lower in patients receiving intravenous MgSO4 within 24 hours after aneurysmal SAH onset. Favorable functional outcome was more likely in the MgSO4 group after 12 months of follow-up.

Will improved neuroradiology facilities debunk the reported rarity of intracranial aneurysms in Sub-Saharan Africa?

Background:

Intracranial aneurysms (IAN) are rare in the Sub-Saharan Africa unlike other parts of the world. The debate is whether the low frequency might be apparent because of the scarcity of advanced neuroimaging services, or real. This study investigated if improved imaging facilities would debunk the rarity of IAN in our subregion.

Methods:

This is a retrospective cohort study of prospectively recorded data of patients with subarachnoid hemorrhage (SAH) and IAN managed over 19 years (2003–2021), at the study center with a catchment population of over 47 million. The center witnessed progressive improvements in neuroimaging facilities: 2-Slice, 8-slice, and 64-slice computed tomography (CT) and 0.35T, 1.5T magnetic resonance imaging (MRI) during the period.

Results:

There were 241 cases of SAH, but only 166 aneurysms were confirmed in 158 patients. Between 2003 and 2008, only 27 IAN patients (4.5 IAN/year) were diagnosed. After introduction of CT angiography/magnetic resonance angiography MRA using 8-slice CT/0.35T magnetic resonance imaging (MRI), between 2009 and 2014, the frequency of IAN increased to 8/year. Between 2015 and 2018 after installation of a 64-slice CT in 2014, the IAN remained the same (8/year). MRI 1.5T was added in 2018, the frequency doubled to 17 cases/year. The females were more (67.7%), the mean age was 46.3 years, but peak incidence was the sixth decade. Internal carotid artery aneurysms including posterior communicating artery were the most common (43%) followed by ACA with anterior communicating artery (24%) and middle cerebral artery (20%). Multiple aneurysms were seen in ten patients.

Conclusion:

Improved neuroimaging between 2003 and 2021 did not debunk the rarity of IAN in our region.

Predictors of In-Hospital Mortality and Home Discharge in Patients with Aneurysmal Subarachnoid Hemorrhage: A 4-Year Retrospective Analysis

BACKGROUND

Factors associated with discharge disposition and mortality following aneurysmal subarachnoid hemorrhage (aSAH) are not well-characterized. We used a national all-payer database to identify factors associated with home discharge and in-hospital mortality.

METHODS

The National Inpatient Sample was queried for patients with aSAH within a 4-year range. Weighted multivariable logistic regression models were constructed and adjusted for age, sex, race, household income, insurance status, comorbidity burden, National Inpatient Sample SAH Severity Score, disease severity, treatment modality, in-hospital complications, and hospital characteristics (size, teaching status, and region).

RESULTS

Our sample included 37,965 patients: 33,605 were discharged alive and 14,350 were discharged home. Black patients had lower odds of in-hospital mortality compared with White patients (adjusted odds ratio [aOR] = 0.67, 95% confidence interval [CI] 0.52-0.86, p = 0.002). Compared with patients with private insurance, those with Medicare were less likely to have a home discharge (aOR = 0.58, 95% CI 0.46-0.74, p < 0.001), whereas those with self-pay (aOR = 2.97, 95% CI 2.29-3.86, p < 0.001) and no charge (aOR = 3.21, 95% CI 1.57-6.55, p = 0.001) were more likely to have a home discharge. Household income percentile was not associated with discharge disposition or in-hospital mortality. Paradoxically, increased number of Elixhauser comorbidities was associated with significantly lower odds of in-hospital mortality.

CONCLUSIONS

We demonstrate independent associations with hospital characteristics, patient characteristics, and treatment characteristics as related to discharge disposition and in-hospital mortality following aSAH, adjusted for disease severity.

Impact of Facility Volume on Patient Safety Indicator Events After Transsphenoidal Pituitary Surgery

OBJECTIVES

To investigate the impact of facility volume on Patient Safety Indicator (PSI) events following transsphenoidal pituitary surgery (TSPS).

STUDY DESIGN

Retrospective database review.

SETTING

National Inpatient Sample database (2003-2011).

METHODS

The National Inpatient Sample was queried for TSPS cases from 2003 to 2011. Facility volume was defined by tertile of average annual number of TSPS procedures performed. PSIs, based on in-hospital complications identified by the Agency of Healthcare Research and Quality, and poor outcomes, such as mortality and tracheostomy, were analyzed.

RESULTS

An overall 16,039 cases were included: 804 had ≥1 PSI and 15,235 had none. A greater proportion of male to female (5.8% vs 4.3%) and Black to White (7.0% vs 4.5%) patients experienced PSIs. There was an increased likelihood of poor outcome (odds ratio [OR], 3.1 [95% CI, 2.5-3.7]; P < .001) and mortality (OR, 30.1 [95% CI, 18.5-48.8]; P < .001) with a PSI. The incidence rates of PSIs at low-, intermediate-, and high-volume facilities were 5.7%, 5.1%, and 4.2%, respectively. Odds of poor outcome with PSIs were greater at low-volume facilities (OR, 3.3 [95% CI, 2.4-4.4]; P < .001) vs intermediate (OR, 3.1 [95% CI, 2.1-4.2]; P < .001) and high (OR, 2.5 [95% CI, 1.7-3.8]; P < .001). Odds of mortality with PSIs were greater at high-volume facilities (OR, 43.0 [95% CI, 14.3-129.4]; P < .001) vs intermediate (OR, 40.0 [95% CI, 18.5-86.4]; P < .001) and low (OR, 17.3 [95% CI, 8.0-37.7]; P < .001).

CONCLUSION

PSIs were associated with a higher likelihood of poor outcome and mortality following TSPS. Patients who experienced PSIs had a lower risk of poor outcome but increased mortality at higher-volume facilities.

Complications of Endovascular and Open Aneurysm Surgery in the Era of Flow Diversion

The techniques used for treatment of intracranial aneurysms have progressed dramatically over the decades. The introduction of modern endovascular techniques and the continued refinement of progressively less invasive neurosurgical approaches have contributed to steadily improving clinical outcomes. Moreover, innovations such as flow-diverting stents have achieved dramatic success and have gained rapid widespread adoption. Particularly in lesions for which the application of conventional treatment techniques is difficult, flow diversion technology has revolutionized aneurysm management. This review provides a discussion on the morbidity and mortality encountered in the treatment of intracranial aneurysms in the modern era. Common adverse events faced in the management of these lesions with open surgery and various endovascular techniques are highlighted.

Microsurgical treatment of ruptured aneurysms beyond 72 hours after rupture: implications for advanced management

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) patients admitted to primary stroke centers are often transferred to neurosurgical and endovascular services at tertiary centers. The effect on microsurgical outcomes of the resultant delay in treatment is unknown. We evaluated microsurgical aSAH treatment > 72 h after the ictus.

METHODS

All aSAH patients treated at a single tertiary center between August 1, 2007, and July 31, 2019, were retrospectively reviewed. The additional inclusion criterion was the availability of treatment data relative to time of bleed. Patients were grouped based on bleed-to-treatment time as having acute treatment (on or before postbleed day [PBD] 3) or delayed treatment (on or after PBD 4). Propensity adjustments were used to correct for statistically significant confounding covariables.

RESULTS

Among 956 aSAH patients, 92 (10%) received delayed surgical treatment (delayed group), and 864 (90%) received acute endovascular or surgical treatment (acute group). Reruptures occurred in 3% (26/864) of the acute group and 1% (1/92) of the delayed group (p = 0.51). After propensity adjustments, the odds of residual aneurysm (OR = 0.09; 95% CI = 0.04-0.17; p < 0.001) or retreatment (OR = 0.14; 95% CI = 0.06-0.29; p < 0.001) was significantly lower among the delayed group. The OR was 0.50 for rerupture, after propensity adjustments, in the delayed setting (p = 0.03). Mean Glasgow Coma Scale scores at admission in the acute and delayed groups were 11.5 and 13.2, respectively (p < 0.001).

CONCLUSIONS

Delayed microsurgical management of aSAH, if required for definitive treatment, appeared to be noninferior with respect to retreatment, residual, and rerupture events in our cohort after adjusting for initial disease severity and significant confounding variables.

Short- and long-term mortality of subarachnoid hemorrhage according to hospital volume and severity using a nationwide multicenter registry study

Introduction

Recent improvements in treatment for subarachnoid hemorrhage (SAH) have decreased the mortality rates; however, the outcomes of SAH management are dependent on many other factors. In this study, we used nationwide, large-scale, observational data to investigate short- and long-term mortality rates after SAH treatment and the influence of patient severity and hospital volume.

Patients and methods

We selected patients with SAH treated with clipping and coiling from the South Korean Acute Stroke Assessment Registry. High- and low-volume hospitals performed ≥20 clipping and coiling procedures and <20 clipping and coiling procedures per year, respectively. Short- and long-term mortality were tracked using data from the Health Insurance Review and Assessment Service.

Results

Among 2,634 patients treated using clipping and coiling, 1,544 (58.6%) and 1,090 (41.4%) were hospitalized in high- and low-volume hospitals, respectively, and 910 (34.5%) and 1,724 (65.5%) were treated with clipping and coiling, respectively. Mortality rates were 13.5, 14.4, 15.2, and 16.1% at 3 months, 1, 2, and 4 years, respectively. High-volume hospitals had a significantly lower 3-month mortality rate. Patients with mild clinical status had a significantly lower 3-month mortality rate in high-volume hospitals than in low-volume hospitals. Patients with severe clinical status had significantly lower 1- and 2-year mortality rates in high-volume hospitals than in low-volume hospitals.

Conclusion

Short- and long-term mortality in patients with SAH differed according to hospital volume. In the modern endovascular era, clipping and coiling can lead to better outcomes in facilities with high stroke-care capabilities.

Regional Variability in the Care and Outcomes of Subarachnoid Hemorrhage Patients in the United States

Background and Objectives

Regional variability in subarachnoid hemorrhage (SAH) care is reported in physician surveys. We aimed to describe variability in SAH care using patient-level data and identify factors impacting hospital outcomes and regional variability in outcomes.

Methods

A retrospective multi-center cross-sectional cohort study of consecutive non-traumatic SAH patients in the Vizient Clinical Data Base, between January 1st, 2009 and December 30th, 2018 was performed. Participating hospitals were divided into US regions: Northeast, Midwest, South, West. Regional demographics, co-morbidities, severity-of-illness, complications, interventions and discharge outcomes were compared. Multivariable logistic regression was performed to identify factors independently associated with primary outcomes: hospital mortality and poor discharge outcome. Poor discharge outcome was defined by the Nationwide Inpatient Sample-SAH Outcome Measure, an externally-validated outcome measure combining death, discharge disposition, tracheostomy and/or gastrostomy. Regional variability in the associations between care and outcomes were assessed by introducing an interaction term for US region into the models.

Results

Of 109,034 patients included, 24.3% were from Northeast, 24.9% Midwest, 34.9% South, 15.9% West. Mean (SD) age was 58.6 (15.6) years and 64,245 (58.9%) were female. In-hospital mortality occurred in 21,991 (20.2%) and 44,159 (40.5%) had poor discharge outcome. There was significant variability in severity-of-illness, co-morbidities, complications and interventions across US regions. Notable findings were higher prevalence of surgical clipping (18.8 vs. 11.6%), delayed cerebral ischemia (4.3 vs. 3.1%), seizures (16.5 vs. 14.8%), infections (18 vs. 14.7%), length of stay (mean [SD] days; 15.7 [19.2] vs. 14.1 [16.7]) and health-care direct costs (mean [SD] USD; 80,379 [98,999]. vs. 58,264 [74,430]) in the West when compared to other regions (all p < 0.0001). Variability in care was also associated with modest variability in hospital mortality and discharge outcome. Aneurysm repair, nimodipine use, later admission-year, endovascular rescue therapies reduced the odds for poor outcome. Age, severity-of-illness, co-morbidities, hospital complications, and vasopressor use increased those odds (c-statistic; mortality: 0.77; discharge outcome: 0.81). Regional interaction effect was significant for admission severity-of-illness, aneurysm-repair and nimodipine-use.

Discussion

Multiple hospital-care factors impact SAH outcomes and significant variability in hospital-care and modest variability in discharge-outcomes exists across the US. Variability in SAH-severity, nimodipine-use and aneurysm-repair may drive variability in outcomes.

Intracranial aneurysm rupture within three days after receiving mRNA anti-COVID-19 vaccination: Three case reports

Background:

Although neurological adverse events have been reported after receiving coronavirus disease 2019 (COVID-19) vaccines, associations between COVID-19 vaccination and aneurysmal subarachnoid hemorrhage (SAH) have rarely been discussed. We report here the incidence and details of three patients who presented with intracranial aneurysm rupture shortly after receiving messenger ribonucleic acid (mRNA) COVID-19 vaccines.

Case Description:

We retrospectively reviewed the medical records of individuals who received a first and/ or second dose of mRNA COVID-19 vaccine between March 6, 2021, and June 14, 2021, in a rural district in Japan, and identified the occurrences of aneurysmal SAH within 3 days after mRNA vaccination. We assessed incidence rates (IRs) for aneurysmal SAH within 3 days after vaccination and spontaneous SAH for March 6–June 14, 2021, and for the March 6–June 14 intervals of a 5-year reference period of 2013–2017. We assessed the incidence rate ratio (IRR) of aneurysmal SAH within 3 days after vaccination and spontaneous SAH compared to the crude incidence in the reference period (2013–2017). Among 34,475 individuals vaccinated during the study period, three women presented with aneurysmal SAH (IR: 1058.7/100,000 person-years), compared with 83 SAHs during the reference period (IR: 20.7/100,000 persons-years). IRR was 0.026 (95% confidence interval [CI] 0.0087–0.12; P < 0.001). A total of 28 spontaneous SAHs were verified from the Iwate Stroke Registry database during the same period in 2021 (IR: 34.9/100,000 person-years), and comparison with the reference period showed an IRR of 0.78 (95%CI 0.53–1.18; P = 0.204). All three cases developed SAH within 3 days (range, 0–3 days) of the first or second dose of BNT162b2 mRNA COVID-19 vaccine by Pfizer/BioNTech. The median age at the time of SAH onset was 63.7 years (range, 44– 75 years). Observed locations of ruptured aneurysms in patients were the bifurcations of the middle cerebral artery, internal carotid-posterior communicating artery, and anterior communicating artery, respectively. Favorable outcomes (modified Rankin scale scores, 0–2) were obtained following microsurgical clipping or intra-aneurysm coiling.

Conclusion:

Although the advantages of COVID-19 vaccination appear to outweigh the risks, pharmacovigilance must be maintained to monitor potentially fatal adverse events and identify possible associations.

The relationship between stroke system organization and disparities in access to stroke center care in California

Background

There are significant racial and ethnic disparities in receipt of reperfusion interventions for acute ischemic stroke. Our objective was to determine whether there are disparities in access to stroke center care by race or ethnicity that help explain differences in reperfusion therapy and to understand whether interhospital patient transfer plays a role in improving access.

Methods

Using statewide administrating data including all emergency department and hospital discharges in California from 2010 to 2017, we identified all acute ischemic stroke patients. Primary outcomes of interest included presentation to primary or comprehensive stroke center (PSC or CSC), interhospital transfer, discharge from PSC or CSC, and discharge from CSC alone. We used hierarchical logistic regression modeling to identify the relationship between patient‐ and hospital‐level characteristics and outcomes of interest.

Results

Of 336,247 ischemic stroke patients, 55.4% were non‐Hispanic White, 19.6% Hispanic, 10.6% non‐Hispanic Asian/Pacific Islander, and 10.3% non‐Hispanic Black. There was no difference in initial presentation to stroke center hospitals between groups. However, adjusted odds of reperfusion intervention, interhospital transfer and discharge from CSC did vary by race and ethnicity. Adjusted odds of interhospital transfer were lower among Hispanic (odds ratio [OR] 0.94, 95% confidence interval [CI] 0.89 to 0.98) and non‐Hispanic Asian/Pacific Islander patients (OR 0.84, 95% CI 0.79 to 0.90) and odds of discharge from a CSC were lower for Hispanic (OR 0.91, 95% CI 0.85 to 0.97) and non‐Hispanic Black patients (OR 0.74, 95% CI 0.67 to 0.81).

Conclusions

There are racial and ethnic disparities in reperfusion intervention receipt among stroke patients in California. Stroke system of care design, hospital resources, and transfer patterns may contribute to this disparity.

Trends in Mortality after Intensive Care of Patients with Aneurysmal Subarachnoid Hemorrhage in Finland in 2003-2019: A Finnish Intensive Care Consortium study

Background

Previous studies suggest that case mortality of aneurysmal subarachnoid hemorrhage (aSAH) has decreased during the last decades, but most studies have been unable to assess case severities among individual patients. We aimed to assess changes in severity-adjusted aSAH mortality in patients admitted to intensive care units (ICUs).

Methods

We conducted a retrospective, register-based study by using the prospectively collected Finnish Intensive Care Consortium database. Four out of five ICUs providing neurosurgical and neurointensive care in Finland participated in the Finnish Intensive Care Consortium. We extracted data on adult patients admitted to Finnish ICUs with aSAH between 2003 and 2019. The primary outcome was 12-month mortality during three periods: 2003–2008, 2009–2014, and 2015–2019. Using a multivariable logistic regression model—with variables including age, sex, World Federation of Neurological Surgeons grade, preadmission dependency, significant comorbidities, and modified Simplified Acute Physiology Score II—we analyzed whether admission period was independently associated with mortality.

Results

A total of 1,847 patients were included in the study. For the periods 2003–2008 and 2015–2019, the mean number of patients with aSAH admitted per year increased from 81 to 123. At the same time, the patients’ median age increased from 55 to 58 years (p = 0.001), and the proportion of patients with World Federation of Neurological Surgeons grades I–III increased from 42 to 58% (p < 0.001). The unadjusted 12-month mortality declined from 30% in 2003–2008 to 23% in 2015–2019 (p = 0.001), but there was no statistically significant change in severity-adjusted mortality.

Conclusions

Between 2003 and 2019, patients with aSAH admitted to ICUs became older and the proportion of less severe cases increased. Unadjusted mortality decreased but age and case severity adjusted–mortality remained unchanged.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-021-01420-z.

Relationship between annualized case volume and in-hospital motality in subarachnoid hemorrhage: A systematic review and meta-analysis

Studies on the relationship between hospital annualized case volume and in-hospital mortality in patients with subarachnoid hemorrhage (SAH) have shown conflicting results. Therefore, we performed a meta-analysis to further examine this relationship.The authors searched the PubMed and Embase databases from inception through July 2020 to identify studies that assessed the relationship between hospital annualized SAH case volume and in-hospital SAH mortality. Studies that reported in-hospital mortality in SAH patients and an adjusted odds ratio (OR) comparing mortality between low-volume and high-volume hospitals or provided core data to calculate an adjusted OR were eligible for inclusion. No language or human subject restrictions were imposed.Five retrospective cohort studies with 46,186 patients were included for analysis. The pooled estimate revealed an inverse relationship between annualized case volume and in-hospital mortality (OR, 0.53; 95% confidence interval, 0.42-0.68, P < .0001). This relationship was consistent in almost all subgroup analyses and was robust in sensitivity analyses.This meta-analysis confirms an inverse relationship between hospital annualized SAH case volume and in-hospital SAH mortality. Higher annualized case volume was associated with lower in-hospital mortality.

Formation, Growth, or Rupture of De Novo Intracranial Aneurysms: Long-Term Follow-up Study of Subarachnoid Hemorrhage Survivors

BACKGROUND

The survival rate of aneurysmal subarachnoid hemorrhage (aSAH) has gradually increased, leading to more clinical cases of de novo intracranial aneurysms (DNIAs).

OBJECTIVE

To identify the characteristics of patients with DNIA growth or rupture.

METHODS

We included 1601 patients with aSAH treated by clipping from January 1993 to May 2010. According to the inclusion and exclusion criteria, 233 patients had no DNIAs, and 63 patients had 77 DNIAs. We assessed the incidence rate of DNIAs and risk factors for DNIA formation. After dichotomizing the DNIA group into the heed (patients with DNIA rupture or growth) and stable groups (patients without DNIA growth), we assessed the risk factors for DNIA growth or rupture.

RESULTS

The total follow-up period was 4427.9 patient-years. The incidence rate per patient-year was 1.42%. Age ≤50 yr, family history of aneurysm, and multiplicity at initial aSAH were significant risk factors for DNIA formation. Multivariate regression analysis revealed that female sex (odds ratio [OR], 5.566; 95% confidence interval [CI], 1.241-24.952), duration from initial aSAH to DNIA detection <120 mo (OR, 5.043; 95% CI, 1.362-18.668), multiplicity at initial aSAH (OR, 4.859; 95% CI, 1.207-19.563), and maximum DNIA diameter ≥4 mm (OR, 11.104; 95% CI, 2.337-52.772) were significant risk factors for DNIA growth or rupture.

CONCLUSION

DNIAs had a higher incidence rate than expected. Taking into account the presented incidence rate and risk factors, long-term surveillance in aSAH survivors for more than a decade may be worth considering, at least on a case-by-case basis.

Association Between Hospital Volumes and Clinical Outcomes for Patients With Nontraumatic Subarachnoid Hemorrhage

Background

Previous studies of patients with nontraumatic subarachnoid hemorrhage (SAH) suggest better outcomes at hospitals with higher case and procedural volumes, but the shape of the volume‐outcome curve has not been defined. We sought to establish minimum volume criteria for SAH and aneurysm obliteration procedures that could be used for comprehensive stroke center certification.

Methods and Results

Data from 8512 discharges in the National Inpatient Sample (NIS) from 2010 to 2011 were analyzed using logistic regression models to evaluate the association between clinical outcomes (in‐hospital mortality and the NIS‐SAH Outcome Measure [NIS‐SOM]) and measures of hospital annual case volume (nontraumatic SAH discharges, coiling, and clipping procedures). Sensitivity and specificity analyses for the association of desirable outcomes with different volume thresholds were performed. During 8512 SAH hospitalizations, 28.7% of cases underwent clipping and 20.1% underwent coiling with rates of 21.2% for in‐hospital mortality and 38.6% for poor outcome on the NIS‐SOM. The mean (range) of SAH, coiling, and clipping annual case volumes were 30.9 (1–195), 8.7 (0–94), and 6.1 (0–69), respectively. Logistic regression demonstrated improved outcomes with increasing annual case volumes of SAH discharges and procedures for aneurysm obliteration, with attenuation of the benefit beyond 35 SAH cases/year. Analysis of sensitivity and specificity using different volume thresholds confirmed these results. Analysis of previously proposed volume thresholds, including those utilized as minimum standards for comprehensive stroke center certification, showed that hospitals with more than 35 SAH cases annually had consistently superior outcomes compared with hospitals with fewer cases, although some hospitals below this threshold had similar outcomes. The adjusted odds ratio demonstrating lower risk of poor outcomes with SAH annual case volume ≥35 compared with 20 to 34 was 0.82 for the NIS‐SOM (95% CI, 0.71–094; P=0.0054) and 0.80 (95% CI, 0.68–0.93; P=0.0055) for in‐hospital mortality.

Conclusions

Outcomes for patients with SAH improve with increasing hospital case volumes and procedure volumes, with consistently better outcomes for hospitals with more than 35 SAH cases per year.

Effects of case volume and comprehensive stroke center capabilities on patient outcomes of clipping and coiling for subarachnoid hemorrhage

OBJECTIVE

Improved outcomes in patients with subarachnoid hemorrhage (SAH) treated at high-volume centers have been reported. The authors sought to examine whether hospital case volume and comprehensive stroke center (CSC) capabilities affect outcomes in patients treated with clipping or coiling for SAH.

METHODS

The authors conducted a nationwide retrospective cohort study in 27,490 SAH patients who underwent clipping or coiling in 621 institutions between 2010 and 2015 and whose data were collected from the Japanese nationwide J-ASPECT Diagnosis Procedure Combination database. The CSC capabilities of each hospital were assessed by use of a validated scoring system based on answers to a previously reported 25-item questionnaire (CSC score 1–25 points). Hospitals were classified into quartiles based on CSC scores and case volumes of clipping or coiling for SAH.

RESULTS

Overall, the absolute risk reductions associated with high versus low case volumes and high versus low CSC scores were relatively small. Nevertheless, in patients who underwent clipping, a high case volume (> 14 cases/yr) was significantly associated with reduced in-hospital mortality (Q1 as control, Q4 OR 0.71, 95% CI 0.55–0.90) but not with short-term poor outcome. In patients who underwent coiling, a high case volume (> 9 cases/yr) was associated with reduced in-hospital mortality (Q4 OR 0.69, 95% CI 0.53–0.90) and short-term poor outcomes (Q3 [> 5 cases/yr] OR 0.75, 95% CI 0.59–0.96 vs Q4 OR 0.65, 95% CI 0.51–0.82). A high CSC score (> 19 points) was significantly associated with reduced in-hospital mortality for clipping (OR 0.68, 95% CI 0.54–0.86) but not coiling treatment. There was no association between CSC capabilities and short-term poor outcomes.

CONCLUSIONS

The effects of case volume and CSC capabilities on in-hospital mortality and short-term functional outcomes in SAH patients differed between patients undergoing clipping and those undergoing coiling. In the modern endovascular era, better outcomes of clipping may be achieved in facilities with high CSC capabilities.

Trends of Ruptured and Unruptured Aneurysms Treatment in the United States in Post-ISAT Era: A National Inpatient Sample Analysis

Background The ISAT (International Subarachnoid Aneurysm Trial) has generated a paradigm shift towards endovascular treatment for intracranial aneurysms but remains unclear if this has led to a true reduction in the risk for aneurysmal subarachnoid hemorrhage (aSAH). We sought to study the association between the treatment burden of unruptured and ruptured aneurysms in the post-ISAT era. Methods and Results Admissions data from the National Inpatient Sample (2004-2014) were extracted, including patients with a primary diagnosis of aSAH or unruptured intracranial aneurysms treated by clipping or coiling. Within each year, this combined group was randomly matched to non-aneurysmal control group, based on age, sex, and Elixhauser comorbidity index. Multinomial regression was performed to calculate the relative risk ratio of undergoing treatment for either ruptured or unruptured aneurysms in comparison with the reference control group, adjusted for time. After adjusting for National Inpatient Sample sampling effects, 243 754 patients with aneurysm were identified, 174 580 (71.6%) were women; mean age, 55.4±13.2 years. A total of 121 882 (50.01%) patients were treated for unruptured aneurysms, 79 627 (65.3%) endovascularly and 42 256 (34.7%) surgically. A total of 121 872 (49.99%) patients underwent procedures for aSAH, 68 921 (56.6%) endovascular, and 52 951 (43.5%) surgically. Multinomial regression revealed a significant year-to-year decrease in aSAH procedures compared with the control group of non-aneurysmal hospitalizations (relative risk ratio, 0.963 per year; P<0.001), while there was no statistical significance for unruptured aneurysms procedures (relative risk ratio, 1.012 per year; P=0.35). Conclusions With each passing year, there is a significant decrease in relative risk ratio of undergoing treatment for aSAH, concomitant with a stable annual risk of undergoing treatment for unruptured intracranial aneurysms.

Trends in Hospital-to-Hospital Transfers for Aneurysmal Subarachnoid Hemorrhage: A Single-Institution Experience from 2006 to 2017

BACKGROUND

Despite evidence to support that aneurysmal subarachnoid hemorrhage (aSAH) is best treated at high-volume centers, it is unknown whether clinical practice reflects these findings.

METHODS

We analyzed patients transferred to our high-volume center for aSAH between 2006 and 2017. Data collection included number of transfers, demographic data, Hunt and Hess score, Fisher score, comorbid conditions, length of stay (LOS), discharge disposition, in-hospital mortality rates, insurance status, and hospital charges. Comparisons were made across 3 time periods (2006-2009, 2010-2013, and 2014-2017) and included subgroup analyses by treatment modality (endovascular vs. microsurgical).

RESULTS

aSAH transfers declined from 213 in 2006-2009 to 160 in 2014-2017. While there was no change in presenting Hunt and Hess scores, the percentage of modified Fisher scores of 4 increased from 2006-2009 to 2014-2017. Transferred patients had a greater comorbidity index and decreased predicted 10-year survival. Despite this, the average LOS decreased. In-hospital mortality decreased from 2006-2009 to 2014-2017, especially in the endovascular cohort. The proportions of patients who were either self-pay or Medicaid did not change. Overall inflation-adjusted hospital charges decreased from $76,975 in 2006-2009 to $59,870 in 2014-2017.

CONCLUSIONS

Between 2006 and 2017, transfers to our center for aSAH declined. However, transferred patients had greater levels of complexity, more comorbidities, and were at greater risk for vasospasm based on their presenting Fisher score. Nonetheless, average LOS, in-hospital mortality, and cost declined. These changing referral patterns have implications for outcome data, quality reporting, resident education, and developing systems of care to optimize outcomes.

Six-month mortality and functional outcomes in aneurysmal sub-arachnoid haemorrhage patients admitted to intensive care units in Australia and New Zealand: A prospective cohort study

Historical studies suggest survivors of aneurysmal sub-arachnoid haemorrhage (SAH) have at least a moderate burden of functional impairment. However, there is a paucity of modern data concerning these outcomes in those admitted to the intensive care unit (ICU). Accordingly, the aim of this multicentre prospective observational cohort study was to provide contemporary epidemiological data concerning 6-month outcomes of adult aneurysmal SAH patients admitted to ICU in Australia and New Zealand (ANZ). Between March 2016 and June 2018 (inclusive), 357 patients requiring ICU admission were enrolled into the study, from eleven (n = 11) neurosurgical centres in ANZ. The majority of patients were female (n = 242, 68%), the median [IQR] age was 57 [49, 67] years, and almost all were living independently prior to their SAH (n = 337, 94%). 38% (n = 134) suffered a high-grade (WFNS 4-5) SAH. The median index ICU and hospital lengths of stay (LOS) were 9 [4-14], and 20 [13-29] days, respectively. In-hospital mortality was 22% (n = 77). Of the evaluable cohort (n = 348), a further nine (n = 9) patients had died by 6-months, yielding an all cause mortality of 25% (n = 86). Moreover, 35% (n = 114) of assessable patients were 'dead or disabled' (modified Rankin scale ≥4) at 6-months, and there was significant variation between sites, independent of SAH severity. Overall, these patients consumed substantial healthcare resources, and given the burden of mortality and morbidity, in addition to the variability between institutions, there may be opportunity to improve patient outcomes.

Management of Aneurysmal Subarachnoid Hemorrhage: Variation in Clinical Practice and Unmet Need for Follow-up among Survivors-A Single-Center Perspective

OBJECTIVE

The purpose of the present study is to investigate the existence and/or prevalence of clinical practice variation in management of aneurysmal subarachnoid hemorrhage (aSAH) and to determine the need for long-term follow-up.

METHODS

A single-center study was carried out of patients with aSAH over a 5-year period divided into 2 halves (2.5 years each) before and after addition of a dually trained cerebrovascular neurosurgeon. In-hospital clinical practice, clinical outcome (mortality and discharge destination) and long-term outcome (modified Rankin Scale score and Telephone Interview for Cognitive Status [TICS]) were compared using descriptive summaries and nonparametric tests.

RESULTS

Among 251 patients admitted with aSAH, 115 (45.8%) were before the index event, whereas 136 (54.2%) were during the later period. The aneurysm-securing procedure changed from coil embolization to clip ligation (12/115 [10.4%] vs. 84/136 [61.8%]; P < 0.0001) during the latter years. Interventional treatment for cerebral vasospasm has decreased (58/115 [50.4%] vs. 49/136 [36.0%]; P = 0.0002). Patients surviving hospitalization had more clinic follow-up after discharge during the latter period (42/85 [49.4%] vs. 76/105 [72.4%]; P = 0.0012) and ventriculoperitoneal shunt placement for delayed hydrocephalus (1/85 [1.2%] vs. 9/105 [8.6%]; P = 0.02). A subcohort of aSAH survivors (n = 46) had lower median TICS score during the earlier study period (31.5 [interquartile range, 22-36] vs. 33 [interquartile range, 27-38]; P = 0.038). Similarly, preictal smoking status and hyperlipidemia were associated with adverse TICS score in a multivariate model (P = 0.007).

CONCLUSIONS

Postdischarge clinical follow-up has improved facilitating recognition and treatment of delayed hydrocephalus. Existence of cognitive deficits among survivors calls for establishment of multidisciplinary clinics for long-term management of aSAH.

Dynamics of outcome after aneurysmal subarachnoid hemorrhage

In this observational study, we analyzed and described the dynamics of the outcome after aneurysmal subarachnoid hemorrhage (SAH) in a collective of 203 cases. We detected a significant improvement of the mean aggregate modified Rankin Score (mRS) in every time interval from discharge to 6 months and up to 1 year. Every forth to fifth patient with potential of recovery (mRS 1-5) at discharge improved by 1 mRS point in the time interval from 6 month to 1 year (22.6%). Patients with mRS 3 at discharge had a remarkable late recovery rate (73.3%, p = 0.000085). Multivariate analysis revealed age ≤ 65 years (odds ratio 4.93; p = 0.0045) and "World Federation of Neurological Surgeons" (WFNS) grades I and II (odds ratio 4.77; p = 0.0077) as significant predictors of early improvement (discharge to 6 months). Absence of a shunting procedure (odds ratio 8.32; p = 0.0049) was a significant predictor of late improvement (6 months to 1 year), but not age ≤ 65 years (p = 0.54) and WFNS grades I and II (p = 0.92). Thus, late recovery (6 month to 1 year) is significant and independent from age and WFNS grade.

The effect of hospital safety-net burden on outcomes, cost, and reportable quality metrics after emergent clipping and coiling of ruptured cerebral aneurysms

OBJECTIVE

Safety-net hospitals deliver care to a substantial share of vulnerable patient populations and are disproportionately impacted by hospital payment reform policies. Complex elective procedures performed at safety-net facilities are associated with worse outcomes and higher costs. The effects of hospital safety-net burden on highly specialized, emergent, and resource-intensive conditions are poorly understood. The authors examined the effects of hospital safety-net burden on outcomes and costs after emergent neurosurgical intervention for ruptured cerebral aneurysms.

METHODS

The authors conducted a retrospective analysis of the Nationwide Inpatient Sample (NIS) from 2002 to 2011. Patients ≥ 18 years old who underwent emergent surgical clipping and endovascular coiling for aneurysmal subarachnoid hemorrhage (SAH) were included. Safety-net burden was defined as the proportion of Medicaid and uninsured patients treated at each hospital included in the NIS database. Hospitals that performed clipping and coiling were stratified as low-burden (LBH), medium-burden (MBH), and high-burden (HBH) hospitals.

RESULTS

A total of 34,647 patients with ruptured cerebral aneurysms underwent clipping and 23,687 underwent coiling. Compared to LBHs, HBHs were more likely to treat black, Hispanic, Medicaid, and uninsured patients (p < 0.001). HBHs were also more likely to be associated with teaching hospitals (p < 0.001). No significant differences were observed among the burden groups in the severity of subarachnoid hemorrhage. After adjusting for patient demographics and hospital characteristics, treatment at an HBH did not predict in-hospital mortality, poor outcome, length of stay, costs, or likelihood of a hospital-acquired condition.

CONCLUSIONS

Despite their financial burden, safety-net hospitals provide equitable care after surgical clipping and endovascular coiling for ruptured cerebral aneurysms and do not incur higher hospital costs. Safety-net hospitals may have the capacity to provide equitable surgical care for highly specialized emergent neurosurgical conditions.

The Impact of Surgical Volume on Outcomes and Cost in Cleft Repair: A Kids' Inpatient Database Analysis

BACKGROUND

Centralization of specialist services, including cleft service delivery, is occurring worldwide with the aim of improving the outcomes. This study examines the relationship between hospital surgical volume in cleft palate repair and outcomes.

METHODS

A retrospective analysis of the Kids' Inpatient Database was undertaken. Children 3 years or younger undergoing cleft palate repair in 2012 were identified. Hospital volume was categorized by cases per year as low volume (LV; 0-14), intermediate volume (IV; 15-46), or high volume (HV; 47-99); differences in complications, hospital costs, and length of stay (LOS) were determined by hospital volume.

RESULTS

Data for 2389 children were retrieved: 24.9% (n = 595) were LV, 50.1% (n = 1196) were IV, and 25.0% (n = 596) were HV. High-volume centers were more frequently located in the West (71.9%) compared with LV (19.9%) or IV (24.5%) centers (P < 0.001 for hospital region). Median household income was more commonly highest quartile in HV centers compared with IV or LV centers (32.3% vs 21.7% vs 18.1%, P < 0.001). There was no difference in complications between different volume centers (P = 0.74). Compared with HV centers, there was a significant decrease in mean costs for LV centers ($9682 vs $,378, P < 0.001) but no significant difference in cost for IV centers ($9260 vs $9682, P = 0.103). Both IV and LV centers had a significantly greater LOS when compared with HV centers (1.97 vs 2.10 vs 1.74, P < 0.001).

CONCLUSIONS

Despite improvement in LOS in HV centers, we did not find a reduction in cost in HV centers. Further research is needed with analysis of outpatient, long-term outcomes to ensure widespread cost-efficiency.

Increased Severe Trauma Patient Volume is Associated With Survival Benefit and Reduced Total Health Care Costs: A Retrospective Observational Study Using a Japanese Nationwide Administrative Database

OBJECTIVE

The aim of this study was to evaluate the associations of severe trauma patient volume with survival benefit and health care costs.

BACKGROUND

The effect of trauma patient volume on survival benefit is inconclusive, and reports on its effects on health care costs are scarce.

METHODS

We conducted a retrospective observational study, including trauma patients who were transferred to government-approved tertiary emergency hospitals, or hospitals with an intensive care unit that provided an equivalent quality of care, using a Japanese nationwide administrative database. We categorized hospitals according to their annual severe trauma patient volumes [1 to 50 (reference), 51 to 100, 101 to 150, 151 to 200, and ≥201]. We evaluated the associations of volume categories with in-hospital survival and total cost per admission using a mixed-effects model adjusting for patient severity and hospital characteristics.

RESULTS

A total of 116,329 patients from 559 hospitals were analyzed. Significantly increased in-hospital survival rates were observed in the second, third, fourth, and highest volume categories compared with the reference category [94.2% in the highest volume category vs 88.8% in the reference category, adjusted odds ratio (95% confidence interval, 95% CI) = 1.75 (1.49-2.07)]. Furthermore, significantly lower costs (in US dollars) were observed in the second and fourth categories [mean (standard deviation) for fourth vs reference = $17,800 ($17,378) vs $20,540 ($32,412), adjusted difference (95% CI) = -$2559 (-$3896 to -$1221)].

CONCLUSIONS

Hospitals with high volumes of severe trauma patients were significantly associated with a survival benefit and lower total cost per admission.

Between-center and between-country differences in outcome after aneurysmal subarachnoid hemorrhage in the Subarachnoid Hemorrhage International Trialists (SAHIT) repository

OBJECTIVE

Differences in clinical outcomes between centers and countries may reflect variation in patient characteristics, diagnostic and therapeutic policies, or quality of care. The purpose of this study was to investigate the presence and magnitude of between-center and between-country differences in outcome after aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

The authors analyzed data from 5972 aSAH patients enrolled in randomized clinical trials of 3 different treatments from the Subarachnoid Hemorrhage International Trialists (SAHIT) repository, including data from 179 centers and 20 countries. They used random effects logistic regression adjusted for patient characteristics and timing of aneurysm treatment to estimate between-center and between-country differences in unfavorable outcome, defined as a Glasgow Outcome Scale score of 1-3 (severe disability, vegetative state, or death) or modified Rankin Scale score of 4-6 (moderately severe disability, severe disability, or death) at 3 months. Between-center and between-country differences were quantified with the median odds ratio (MOR), which can be interpreted as the ratio of odds of unfavorable outcome between a typical high-risk and a typical low-risk center or country.

RESULTS

The proportion of patients with unfavorable outcome was 27% (n = 1599). The authors found substantial between-center differences (MOR 1.26, 95% CI 1.16-1.52), which could not be explained by patient characteristics and timing of aneurysm treatment (adjusted MOR 1.21, 95% CI 1.11-1.44). They observed no between-country differences (adjusted MOR 1.13, 95% CI 1.00-1.40).

CONCLUSIONS

Clinical outcomes after aSAH differ between centers. These differences could not be explained by patient characteristics or timing of aneurysm treatment. Further research is needed to confirm the presence of differences in outcome after aSAH between hospitals in more recent data and to investigate potential causes.

Hypernatremia is associated with poorer outcomes following aneurysmal subarachnoid hemorrhage: a nationwide inpatient sample analysis

BACKGROUND

Hypernatremia is one of the most common electrolyte disturbances following aneurysmal subarachnoid hemorrhage (aSAH) and has been correlated with increased mortality in single institution studies. We investigated this association using a large nationwide healthcare database.

METHODS

We performed a retrospective analysis of adults between 2002 and 2011 with a primary diagnosis of aSAH using the Nationwide Inpatient Sample (NIS). Patients were grouped according to whether or not an inpatient diagnosis of hypernatremia was present. The primary outcome was the NIS-SAH outcome measure. Secondary outcomes included in-hospital mortality, length of stay (LOS), and non-routine hospital discharge. Outcomes analyses adjusted for SAH severity using the NIS-SAH Severity Score, Charlson Comorbidity Index, and the presence of cerebral edema.

RESULTS

A total of 18,377 patients were included in the study. The incidence of a poor outcome as defined by the NIS-SAH outcome measure was 65.9% in the hypernatremia group and 33.4% in the normonatremia group (OR 1.96, 95% CI 1.68 - 2.27). There was higher mortality in the hypernatremia group (OR 1.60, 95% CI 1.37 - 1.87). Patients with hypernatremia had a significantly higher rate of non-routine hospital discharge and gastrostomy. The incidences of poor outcome, in-hospital mortality, and non-routine disposition were higher in the hypernatremia group regardless of treatment type (clipping vs. endovascular embolization). Pulmonary complications and acute kidney injury were more common in the hypernatremia group as well.

CONCLUSIONS

In patients with aSAH, hypernatremia is associated with poorer functional outcomes regardless of SAH severity.

A Large Database Analysis of Rates of Aneurysm Screening, Elective Treatment, and Subarachnoid Hemorrhage in Patients With Polycystic Kidney Disease

BACKGROUND

Professional societies provide conflicting guidelines on aneurysm screening in patients with polycystic kidney disease (PKD), and the rate of subarachnoid hemorrhage (SAH) is poorly understood.

OBJECTIVE

To evaluate screening, elective treatment, and the rate of SAH in patients with known PKD.

METHODS

We examined longitudinally linked claims data from a large private insurer, identifying screening, elective treatment, aneurysmal subarachnoid hemorrhage (aSAH) and secured aneurysmal SAH (saSAH) in 2004 to 2014 amongst patients with known PKD.

RESULTS

We identified 20 704 patients diagnosed with PKD. Among patients with an initial PKD diagnosis, 51/446 (15.9%) underwent angiographic screening within 2 yr. Forty aneurysms were treated electively in 48 868 yr at risk in PKD patients (82/100K patient yr, 95% confidence interval [CI] 60-112) vs 24 elective treatments in 349 861 yr at risk in age- and sex-matched controls (7/100K patient yr, 95% CI 5-10, P < .0001). Eleven admissions for aSAH were identified in PKD patients (23/100K patient yr, 95% CI 13-41) and 22 admissions for aSAH in controls (6/100K patient yr, 95% CI 4-10), giving an incidence rate ratio (IRR) of 3.6 (95% CI 1.7-7.4, P < .0001) and a comorbidity-adjusted IRR of 3.1 (95% CI 1.4-6.9). The incidence of saSAH was proportionally even higher in PKD patients than controls, 16 vs 2/100K patient years, IRR 9.5 (95% CI 3.3-27.5, P < .0001).

CONCLUSION

Screening in PKD is performed only selectively, though resulting rates of elective treatment were over 10× those of controls. Despite screening and treatment, the rate of SAH remains significantly elevated over that of controls.

Nationwide analysis of hospital-to-hospital transfer in patients with aneurysmal subarachnoid hemorrhage requiring aneurysm repair

OBJECTIVE

Aneurysmal subarachnoid hemorrhage (aSAH) has devastating consequences. The association between higher institutional volumes and improved outcomes for aSAH patients has been studied extensively. However, the literature exploring patterns of transfer in this context is sparse. Expansion of the endovascular workforce has raised concerns about the decentralization of care, reduced institutional volumes, and worsened patient outcomes. In this paper, the authors explored various patient and hospital factors associated with the transfer of aSAH patients by using a nationally representative database.

METHODS

The 2013 and 2014 years of the National Inpatient Sample (NIS) were used to define an observational cohort of patients with ruptured brain aneurysms. The initial search identified patients with SAH (ICD-9-CM 430). Those with concomitant codes suggesting trauma or other intracranial vascular abnormalities were excluded. Finally, the patients who had not undergone a subsequent procedure to repair an intracranial aneurysm were excluded. These criteria yielded a cohort of 4373 patients, 1379 of whom had undergone microsurgical clip ligation and 2994 of whom had undergone endovascular repair. The outcome of interest was transfer status, and the NIS data element TRAN_IN was used to define this state. Multiple explanatory variables were identified, including age, sex, primary payer, median household income by zip code, race, hospital size, hospital control, hospital teaching status, and hospital location. These variables were evaluated using descriptive statistics, bivariate correlation analysis, and multivariable logistic regression modeling to determine their relationship with transfer status.

RESULTS

Patients with aSAH who were treated in an urban teaching hospital had higher odds of being a transfer (OR 2.15, 95% CI 1.71-2.72) than the patients in urban nonteaching hospitals. White patients were more likely to be transfer patients than were any of the other racial groups (p < 0.0001). Moreover, patients who lived in the highest-income zip codes were less likely to be transferred than the patients in the lowest income quartile (OR 0.78, 95% CI 0.64-0.95). Repair type (clip vs coil) and primary payer were not associated with transfer status.

CONCLUSIONS

A relatively high percentage of patients with aSAH are transferred between acute care hospitals. Race and income were associated with transfer status. White patients are more likely to be transferred than other races. Patients from zip codes with the highest income transferred at lower rates than those from the lowest income quartile. Transfer patients were preferentially sent to urban teaching hospitals. The modality of aneurysm treatment was not associated with transfer status.

Association between volume of surgery for acute hemorrhagic stroke and mortality

This study aimed to investigate the association between volume of surgery and mortality in relation to interventions for acute hemorrhagic stroke, namely craniotomy and trephination.We obtained data on acute hemorrhagic stroke patients for a 5-year period (2009-2013) from the Health Insurance Review and Assessment Service. Hospitals were classified into 3 categories according to volume of surgery (low, medium, high). To avoid intentionally setting a cutoff, we placed the hospitals in order from those with high volume of surgery to those with low volume of surgery and divided them into 3 groups (tertile) according to the number of patients. The covariates were age, sex, hemorrhagic stroke site, type of health insurance, intensive care unit admission, history of hypertension, and Charlson comorbidity index. Multiple logistic regression analysis was performed with statistical significance set at 5%.A total of 41,917 patients who underwent craniotomy (n = 20,982) or trephination (n = 20,935) for acute hemorrhagic stroke were analyzed according to hemorrhage site (subarachnoid and others). The results showed that mortality from acute hemorrhagic stroke decreased with increasing volume of surgery. For subarachnoid hemorrhage, the odds ratios of the medium- and high-volume surgery groups were significantly lower (0.74 and 0.59, respectively) for mortality within 7 days of admission, and were also significantly lower (0.78 and 0.68) for mortality within 30 days of admission than that of the low-volume surgery group. The results for other hemorrhage sites were similar. The association between mortality and volume of surgery was more evident in the craniotomy group. Although this study was limited to a single country (South Korea), it partially addressed the shortcomings of previous studies by analyzing a nationwide database and examining all types of hemorrhagic strokes.

Relationship between patient safety indicator events and comprehensive stroke center volume status in the treatment of unruptured cerebral aneurysms

OBJECTIVE

The Agency of Healthcare Research and Quality (AHRQ) has defined Patient Safety Indicators (PSIs) for assessments in quality of inpatient care. The hypothesis of this study is that, in the treatment of unruptured cerebral aneurysms (UCAs), PSI events are less likely to occur in hospitals meeting the volume thresholds defined by The Joint Commission for Comprehensive Stroke Center (CSC) certification.

METHODS

Using the 2002–2011 National (Nationwide) Inpatient Sample, patients treated electively for a nonruptured cerebral aneurysm were selected. Patients were evaluated for PSI events (e.g., pressure ulcers, retained surgical item, perioperative hemorrhage, pulmonary embolism, sepsis) defined by AHRQ-specified ICD-9 codes. Hospitals were categorized by treatment volume into CSC or non-CSC volume status based on The Joint Commission’s annual volume thresholds of at least 20 patients with subarachnoid hemorrhage and performance of 15 or more endovascular coiling or surgical clipping procedures for aneurysms.

RESULTS

A total of 65,824 patients underwent treatment for an unruptured cerebral aneurysm. There were 4818 patients (7.3%) in whom at least 1 PSI event occurred. The overall inpatient mortality rate was 0.7%. In patients with a PSI event, this rate increased to 7% compared with 0.2% in patients without a PSI event (p < 0.0001). The overall rate of poor outcome was 3.8%. In patients with a PSI event, this rate increased to 23.3% compared with 2.3% in patients without a PSI event (p < 0.0001). There were significant differences in PSI event, poor outcome, and mortality rates between non-CSC and CSC volume-status hospitals (PSI event, 8.4% vs 7.2%; poor outcome, 5.1% vs 3.6%; and mortality, 1% vs 0.6%). In multivariate analysis, all patients treated at a non-CSC volume-status hospital were more likely to suffer a PSI event with an OR of 1.2 (1.1–1.3). In patients who underwent surgery, this relationship was more substantial, with an OR of 1.4 (1.2–1.6). The relationship was not significant in the endovascularly treated patients.

CONCLUSIONS

In the treatment of unruptured cerebral aneurysms, PSI events occur relatively frequently and are associated with significant increases in morbidity and mortality. In patients treated at institutions achieving the volume thresholds for CSC certification, the likelihood of having a PSI event, and therefore the likelihood of poor outcome and mortality, was significantly decreased. These improvements are being driven by the improved outcomes in surgical patients, whereas outcomes and mortality in patients treated endovascularly were not sensitive to the CSC volume status of the hospital and showed no significant relationship with treatment volumes.

Hospital case-volume is associated with case-fatality after aneurysmal subarachnoid hemorrhage

Background

Inverse association between hospital case-volume and case-fatality has been observed for various nonsurgical interventions and surgical procedures.

Aims

To study the impact of hospital case-volume on outcome after aneurysmal subarachnoid hemorrhage (aSAH).

Methods

We included aSAH patients who underwent aneurysm coiling or clipping from tertiary care medical centers across three continents using the Dr Foster Stroke GOAL database 2007–2014. Hospitals were categorized by annual case-volume (low volume: <41/year; intermediate: 41–70/year; high: >70/year). Primary outcome was 14-day in-hospital case-fatality. We calculated proportions, and used multiple logistic regression to adjust for age, sex, differences in comorbidity or disease severity, aneurysm treatment modality, and hospital.

Results

We included 8525 patients (2363 treated in low volume hospitals, 3563 treated in intermediate volume hospitals, and 2599 in high-volume hospitals). Crude 14-day case-fatality for hospitals with low case-volume was 10.4% (95% confidence interval (CI) 9.2–11.7%), for intermediate volume 7.0% (95% CI 6.2–7.9%; adjusted odds ratio (OR) 0.63 (95%CI 0.47–0.85)) and for high volume 5.4% (95% CI 4.6–6.3%; adjusted OR 0.50 (95% CI 0.33–0.74)). In patients with clipped aneurysms, adjusted OR for 14-day case-fatality was 0.46 (95% CI 0.30–0.71) for hospitals with intermediate case-volume and 0.42 (95% CI 0.25–0.72) with high case-volume. In patients with coiled aneurysms, adjusted OR was 0.77 (95% CI 0.55–1.07) for hospitals with intermediate case-volume and 0.56 (95% CI 0.36–0.87) with high case-volume.

Conclusions

Even within a subset of large, tertiary care centers, intermediate and high hospital case-volume is associated with lower case-fatality after aSAH regardless of treatment modality, supporting centralization to higher volume centers.

Clipping aneurysms improves outcomes for patients undergoing coiling

OBJECTIVE

Most intracranial aneurysms are now treated by endovascular rather than by microsurgical procedures. There is evidence to demonstrate superior outcomes for patients with aneurysmal subarachnoid hemorrhage (aSAH) treated by endovascular techniques. However, some cases continue to require microsurgery. The authors have examined the relationship between the number of aneurysms treated by microsurgery and outcome for patients undergoing treatment for aSAH at neurosurgical centers in England.

METHODS

The Neurosurgical National Audit Programme (NNAP) database was used to identify aSAH cases and to provide associated 30-day mortality rates for each of the 24 neurosurgical centers in England. Data were compared for association by regression analysis using the Pearson product-moment correlation coefficient and any associations were tested for statistical significance using the one-way ANOVA test. The NNAP data were validated utilizing a second, independent registry: the British Neurovascular Group's (BNVG) National Subarachnoid Haemorrhage Database.

RESULTS

Increasing numbers of microsurgical cases in a center are associated with lower 30-day mortality rates for all patients treated for aSAH, irrespective of treatment modality (Pearson r = 0.42, p = 0.04), and for patients treated for aSAH by endovascular procedures (Pearson r = 0.42, p = 0.04). The correlations are stronger if all (elective and acute) microsurgical cases are compared with outcome. The BNVG data validated the NNAP data set for patients with aSAH.

CONCLUSIONS

There is a statistically significant association between local microsurgical activity and center outcomes for patients with aSAH, even for patients treated endovascularly. The authors postulate that the number of microsurgical cases performed may be a surrogate indicator of closer neurosurgical involvement in the overall management of neurovascular patients and of optimal case selection.

Impact of Weekend Presentation on Short-Term Outcomes and Choice of Clipping vs Coiling in Subarachnoid Hemorrhage

BACKGROUND

Presentation on a weekend is commonly associated with higher mortality and a decreased likelihood of receiving invasive procedures.

OBJECTIVE

To determine whether weekend presentation influences mortality, discharge destination, or type of treatment received (clip vs coil) in subarachnoid hemorrhage (SAH).

METHODS

We performed a serial cross-sectional retrospective study using the Nationwide Inpatient Sample. All adult discharges with a primary diagnosis of SAH (ICD-9-CM 435) from 2005 to 2010 were included, and records with trauma or arteriovenous malformation were excluded. Unadjusted and adjusted associations between weekend presentation and 3 outcomes (in-hospital mortality, discharge destination, and treatment with clip vs coil) were estimated using chi-square tests and multilevel logistic regression.

RESULTS

A total of 46 093 admissions for nontraumatic SAH were included in the sample; 24.6% presented on a weekend, 68.9% on a weekday, and 6.5% had unknown day of presentation. Weekend admission was not a significant predictor of inpatient mortality (25.4% weekend vs 24.9% weekday; P = .44), or a combined poor outcome measure of mortality or discharge to long-term acute care or hospice (30.3% weekend vs 29.4% weekday; P = .23). Among those treated for aneurysm obliteration, the proportion of clipped vs coiled did not change with weekend vs weekday presentation (21.5% clipped with weekend presentation vs 21.6% weekday, P = .95; 21.5% coiled with weekend presentation vs 22.4% weekday, P = .19).

CONCLUSION

Presentation with nontraumatic SAH on a weekend did not influence mortality, discharge destination, or type of treatment received (clip vs coil) compared with weekday presentation.

Treatment Modality and Quality Benchmarks of Aneurysmal Subarachnoid Hemorrhage at a Comprehensive Stroke Center

Background

Aneurysmal subarachnoid hemorrhage (aSAH) is the most severe type of stroke. In 2012, the Joint Commission, in collaboration with the American Heart Association/American Stroke Association (AHA/ASA), launched the Advanced Certification for Comprehensive Stroke Centers (CSCs). This new level of certification was designed to promote higher standard of care for patients with complex stroke.

Objective

The goal of this study was to examine the treatment modality and quality benchmarks of aSAH at one of the first five certified CSCs in the United States.

Methods

Consecutive patients with aSAH at Cedars-Sinai Medical Center between April 1, 2012 and May 30, 2014 were included for this retrospective study. The ruptured aneurysm was treated with coiling or clipping within 24 h. All patients were managed per AHA guidelines. Discharge outcomes were assessed using modified Rankin Scale (mRS). The rate of aneurysm treatment, door-to-treatment time, rate of posttreatment rebleed, hospital length of stay (LOS), discharge outcome, and mortality rates were evaluated as quality indicators.

Results

The median age (interquartile range) of the 118 patients with aSAH was 55 (19). Among them, 84 (71.2%) were females, 94 (79.7%) were transfers from outside hospitals, and 74 (62.7%) had Hunt and Hess grades 1-3. Sixty patients (50.8%) were treated with coiling, 52 (44.1%) with clipping, and 6 (5.1%) untreated due to ictal cardiac arrest or severe comorbidities. The rate of aneurysm treatment was 95% (112/118) with median door-to-treatment time at 12.5 (8.5) h and 0.9% (1/112) posttreatment rebleed. The median ICU and hospital LOS were 12.5 (7) and 17.0 (14.5) days, respectively. Coiling was associated with significantly shorter LOS than clipping. There were 59 patients (50%) with favorable outcome and 19 deaths (16.1%) at hospital discharge. There was no significant difference in discharge outcome between coiling and clipping.

Conclusion

Care of aSAH at one of the early CSCs in the United States was associated with high rate of aneurysm treatment, fast door-to-treatment time, low posttreatment rebleed, excellent outcome, and low mortality rate. Coiling was associated with significant shorter LOS than clipping. There was no significant difference in discharge outcomes between treatment modalities.

Contemporary endovascular and open aneurysm treatment in the era of flow diversion

Clinical outcomes have improved considerably over the last decade for patients with ruptured and unruptured aneurysms. Modern endovascular techniques, such as flow diversion, are associated with high aneurysm occlusion rates and have become a popular treatment modality for many types of aneurysms. However, the safety and effectiveness of flow diversion has not yet been established in trials comparing it with traditional aneurysm treatments. Moreover, there are some types of aneurysms that may not be appropriate for endovascular coiling, such as wide-necked aneurysms located at branch points of major vessels, large saccular aneurysms with multiple efferent arteries, dolichoectatic aneurysms, large aneurysms with mass effect, when there are technical complications with endovascular treatment, when patients cannot tolerate or have contraindications to antiplatelet therapy or in the setting of a subarachnoid haemorrhage. For these cases, open cerebrovascular surgery remains important. This review provides a discussion on the current trends and evidence for both flow diversion and open cerebrovascular surgery for complex aneurysms that may not be suitable for coiling. We emphasise a continued important role for surgical treatment in certain situations.

Validation of a neurovascular comorbidities index for retrospective database analysis

OBJECTIVE: Comorbidities have a significant effect on patient outcomes. Accounting for this effect is especially important in retrospective reviews of large databases; overpowered studies are at risk for finding significant results because of inaccurate patient risk stratification. The authors previously created a neurovascular comorbidities index (NCI) for patients with an unruptured intracranial aneurysm and found that the model's ability to predict patient outcomes was statistically significantly improved over that of the routinely used Charlson Comorbidity Index (CCI) and Elixhauser Comorbidity Index (ECI). In this study, the authors aimed to validate use of the NCI over that of the CCI and ECI for risk stratification of patients with other neurovascular diseases. METHODS: The authors queried the National (Nationwide) Inpatient Sample database for the years 2002-2012 to compare the accuracy of the previously validated NCI with that of the CCI and ECI with respect to predicting outcomes for patients who had an arteriovenous malformation, a ruptured intracranial aneurysm, carotid artery stenosis, or dural arteriovenous fistula and who underwent surgical intervention. RESULTS: For patients with an arteriovenous malformation, the NCI outperformed the CCI and ECI in predicting poor outcome, hospital length of stay (LOS), and total cost but was equivalent to the CCI in predicting death. For patients with a ruptured intracranial aneurysm, the NCI outperformed the ECI and CCI in predicting death, poor outcome, LOS, and total cost. For patients with carotid artery stenosis, the NCI outperformed the ECI and CCI in predicting LOS, but it was equivalent to the ECI in predicting death and total cost and inferior to the CCI in predicting poor outcome (p < 0.002 for all). An insufficient number of patients with dural arteriovenous fistula who underwent surgical intervention were available for analysis (n < 10), and they therefore were excluded from study. For 11 of 12 metrics, the NCI was the significantly more efficient model. CONCLUSIONS: The NCI outperforms the CCI and ECI by providing more appropriate and efficient risk stratification of patients regarding death, outcome, LOS, and cost. Given this finding, the NCI should be used for retrospective reviews of patient outcomes instead of the CCI or ECI.

Recognized focused practice: Does sub-specialty designation offer value to the neurosurgeon?

Vehicles for life-long assessment such as Maintenance of Certification tend to focus on generalist neurosurgical knowledge. However, as neurosurgeons advance in their careers, they tend to narrow their practice and increase volumes in certain specific types of operations. Failing to test the type of procedures most relevant to the practitioner is a lost opportunity to improve the knowledge and practice of the individual neurosurgeon. In this study, we assess the neurosurgical community’s appetite for designations of board-recognized Recognized Focused Practice (RFP). We administered a validated, online, confidential survey to 4,899 neurosurgeons (2,435 American Board of Neurological Surgery (ABNS) Diplomates participating in MOC, 1,440 Diplomates certified prior to 1999 (grandfathered), and 1,024 retired Diplomates). We received 1,449 responses overall (30% response rate). A plurality of respondents were in practice 11–15 years (18.5%), in private practice (40%) and participate in MOC (61%). 49% of respondents felt that a RFP designation would not be helpful. For the 30% who felt that RFP would be helpful, 61.3% felt that it would support recognition by their hospital or practice, it would motivate them to stay current on medical knowledge (53.4%), or it would help attract patients (46.4%;). The most popular suggestions for RFP were Spine (56.2%), Cerebrovascular (62.9%), Pediatrics (64.1%), and Functional/Stereotactic (52%). A plurality of neurosurgeons (35.7%) felt that RFP should recognize neurosurgeons with accredited and non-accredited fellowship experience and sub-specialty experience. Ultimately, Recognized Focused Practice may provide value to individual neurosurgeons, but the neurosurgical community shows tepid interest for pursuing this designation.

Proposing a validated clinical app predicting hospitalization cost for extracranial-intracranial bypass surgery

OBJECT

United States healthcare reforms are focused on curtailing rising expenditures. In neurosurgical domain, limited or no data exists identifying potential modifiable targets associated with high-hospitalization cost for cerebrovascular procedures such as extracranial-intracranial (ECIC) bypass. Our study objective was to develop a predictive model of initial cost for patients undergoing bypass surgery.

METHODS

In an observational cohort study, we analyzed patients registered in the Nationwide Inpatient Sample (2002-2011) that underwent ECIC bypass. Split-sample 1:1 randomization of the study cohort was performed. Hospital cost data was modelled using ordinary least square to identity potential drivers impacting initial hospitalization cost. Subsequently, a validated clinical app for estimated hospitalization cost is proposed (https://www.neurosurgerycost.com/calc/ec-ic-by-pass).

RESULTS

Overall, 1533 patients [mean age: 45.18 ± 19.51 years; 58% female] underwent ECIC bypass for moyamoya disease [45.1%], cerebro-occlusive disease (COD) [23% without infarction; 12% with infarction], unruptured [12%] and ruptured [4%] aneurysms. Median hospitalization cost was $37,525 (IQR: $16,225-$58,825). Common drivers impacting cost include Asian race, private payer, elective admission, hyponatremia, neurological and respiratory complications, acute renal failure, bypass for moyamoya disease, COD without infarction, medium and high volume centers, hospitals located in Midwest, Northeast, and West region, total number of diagnosis and procedures, days to bypass and post-procedural LOS. Our model was validated in an independent cohort and using 1000-bootstrapped replacement samples.

CONCLUSIONS

Identified drivers of hospital cost after ECIC bypass could potentially be used as an adjunct for creation of data driven policies, impact reimbursement criteria, aid in-hospital auditing, and in the cost containment debate.

Operative Landscape at Canadian Neurosurgery Residency Programs

Background Currently, the literature lacks reliable data regarding operative case volumes at Canadian neurosurgery residency programs. Our objective was to provide a snapshot of the operative landscape in Canadian neurosurgical training using the trainee-led Canadian Neurosurgery Research Collaborative.

METHODS

Anonymized administrative operative data were gathered from each neurosurgery residency program from January 1, 2014, to December 31, 2014. Procedures were broadly classified into cranial, spine, peripheral nerve, and miscellaneous procedures. A number of prespecified subspecialty procedures were recorded. We defined the resident case index as the ratio of the total number of operations to the total number of neurosurgery residents in that program. Resident number included both Canadian medical and international medical graduates, and included residents on the neurosurgery service, off-service, or on leave for research or other personal reasons.

RESULTS

Overall, there was an average of 1845 operative cases per neurosurgery residency program. The mean numbers of cranial, spine, peripheral nerve, and miscellaneous procedures were 725, 466, 48, and 193, respectively. The nationwide mean resident case indices for cranial, spine, peripheral nerve, and total procedures were 90, 58, 5, and 196, respectively. There was some variation in the resident case indices for specific subspecialty procedures, with some training programs not performing carotid endarterectomy or endoscopic transsphenoidal procedures.

CONCLUSIONS

This study presents the breadth of neurosurgical training within Canadian neurosurgery residency programs. These results may help inform the implementation of neurosurgery training as the Royal College of Physicians and Surgeons residency training transitions to a competence-by-design curriculum.