A predictive model of outcomes during cerebral aneurysm coiling

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.

Untapped potential of multicenter studies: a review of cardiovascular risk prediction models revealed inappropriate analyses and wide variation in reporting

BACKGROUND

Clinical prediction models are often constructed using multicenter databases. Such a data structure poses additional challenges for statistical analysis (clustered data) but offers opportunities for model generalizability to a broad range of centers. The purpose of this study was to describe properties, analysis, and reporting of multicenter studies in the Tufts PACE Clinical Prediction Model Registry and to illustrate consequences of common design and analyses choices.

METHODS

Fifty randomly selected studies that are included in the Tufts registry as multicenter and published after 2000 underwent full-text screening. Simulated examples illustrate some key concepts relevant to multicenter prediction research.

RESULTS

Multicenter studies differed widely in the number of participating centers (range 2 to 5473). Thirty-nine of 50 studies ignored the multicenter nature of data in the statistical analysis. In the others, clustering was resolved by developing the model on only one center, using mixed effects or stratified regression, or by using center-level characteristics as predictors. Twenty-three of 50 studies did not describe the clinical settings or type of centers from which data was obtained. Four of 50 studies discussed neither generalizability nor external validity of the developed model.

CONCLUSIONS

Regression methods and validation strategies tailored to multicenter studies are underutilized. Reporting on generalizability and potential external validity of the model lacks transparency. Hence, multicenter prediction research has untapped potential.

REGISTRATION

This review was not registered.

Age-specific global epidemiology of hydrocephalus: Systematic review, metanalysis and global birth surveillance

Background

Hydrocephalus is a debilitating disorder, affecting all age groups. Evaluation of its global epidemiology is required for healthcare planning and resource allocation.

Objectives

To define age-specific global prevalence and incidence of hydrocephalus.

Methods

Population-based studies reporting prevalence of hydrocephalus were identified (MEDLINE, EMBASE, Cochrane, and Google Scholar (1985–2017)). Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Two authors reviewed abstracts, full text articles and abstracted data. Metanalysis and meta-regressions were used to assess associations between key variables. Heterogeneity and publication bias were assessed. Main outcome of interest was hydrocephalus prevalence among pediatric (≤ 18 years), adults (19–64 years), and elderly (≥ 65) patients. Annual hydrocephalus incidence stratified by country income level and folate fortification requirements were obtained (2003–2014) from the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR).

Results

Of 2,460 abstracts, 52 met review eligibility criteria (aggregate population 171,558,651). Mean hydrocephalus prevalence was 85/100,000 [95% CI 62, 116]. The prevalence was 88/100,000 [95% CI 72, 107] in pediatrics; 11/100,000 [95% CI 5, 25] in adults; and 175/100,000 [95% CI 67, 458] in the elderly. The ICBDSR-based incidence of hydrocephalus diagnosed at birth remained stable over 11 years: 81/100,000 [95% CI 69, 96]. A significantly lower incidence was identified in high-income countries.

Conclusion

This systematic review established age-specific global hydrocephalus prevalence. While high-income countries had a lower hydrocephalus incidence according to the ICBDSR registry, folate fortification status was not associated with incidence. Our findings may inform future healthcare resource allocation and study.

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.

Development and Validation of the Procedure-Related Neurologic Complications Risk Score for Elderly Patients with Ruptured Intracranial Aneurysm Undergoing Endovascular Treatment

OBJECTIVES

Our aim was to develop and validate a procedure-related neurologic complications (PNC) risk score for individual elderly patients with ruptured intracranial aneurysms undergoing endovascular treatment (EVT).

METHODS

Preoperatively collected data, including clinical, lesion, and procedure characteristics of consecutive elderly patients (≥60 years), were used to develop a PNC risk predictive score based on the coefficients (β) of a multivariable logistic regression analysis. The PNC included intraprocedural rupture, thromboembolic events, and rebleeding within 30 days after EVT.

RESULTS

Overall, 520 elderly patients who underwent EVT were enrolled. At 30 days, the PNC rate was 13.08%. Six risk factors were independently associated with PNC and comprised the PNC score (PNC score, 0-16 points): hypertension (2 points), Hunt-Hess grade ≥4 (3 points), Fisher grade ≥3 (2 points), wide-necked aneurysm (2 points), with a bleb on the aneurysm sac (3 points), and aneurysm size (3-10 mm, 1 point; <3 mm, 4 points). The PNC score model predicted the risk of PNC at a sensitivity of 63.22% and specificity of 84.79%. Moreover, the PNC score demonstrated significant discrimination (area under curve, 0.799; P < 0.001) and calibration (Hosmer-Lemeshow test, P = 0.319). Excellent prediction, discrimination, and calibration properties were reproduced by the internal validation group with bootstrapping techniques.

CONCLUSIONS

The PNC score can be an easily applicable tool for predicting the risk of PNC for individual elderly patients with ruptured intracranial aneurysms undergoing EVT. Our study provides large case-based evidence supporting the integration of individual clinical, lesion, and procedure characteristics to predict PNC risk.

Association of Prior Falls with Adverse Outcomes After Neurosurgical Operations in the Elderly

BACKGROUND

Despite the increasing number of elderly patients undergoing neurosurgical interventions, there are limited resources for preoperative assessment of frailty in this population. We investigated the association between recent history of falls and surgical outcomes for these patients.

METHODS

We performed a prospective cohort study of all patients, 65 years and older, undergoing elective neurosurgical procedures from 2014-2015 in a tertiary referral medical center. We examined the association of sustaining a fall in the 6 months before the operation with discharge to a facility, readmissions, and complications in the first 30 days after discharge. In order to control for confounding, we used multivariable regression models and propensity score conditioning. Mixed-effects models were used to control for clustering at the surgeon level.

RESULTS

During the study period, 143 elderly patients underwent a neurosurgical procedure and met the inclusion criteria. Of these, 53.1% had a history of falls preoperatively. Mixed-effects multivariable logistic regression analysis demonstrated an association between preoperative falls and discharge to a facility (odds ratio [OR], 1.35; 95% confidence interval [CI], 1.23-1.47), 30-day readmissions (OR, 1.57; 95% CI, 1.36-1.78), and 30-day complications (OR, 1.13; 95% CI, 1.03-1.23). Similar associations were present in propensity score-adjusted models and models stratified by cranial and spinal procedures.

CONCLUSIONS

History of at least 1 fall in the 6 months before a neurosurgical operation was associated with increased risk of discharge to a facility, readmissions, and complications in the first 30 days after discharge. History of prior falls should be taken into account during the preoperative risk assessment of neurosurgical patients.

The impact of body habitus on outcomes after aneurysmal subarachnoid hemorrhage: a Nationwide Inpatient Sample analysis

OBJECTIVE Although the prevalence of obesity is increasing rapidly both nationally and internationally, few studies have analyzed outcomes among obese patients undergoing cranial neurosurgery. The goal of this study, which used a nationwide data set, was to evaluate the association of both obesity and morbid obesity with treatment outcomes among patients with aneurysmal subarachnoid hemorrhage (SAH); in addition, the authors sought to analyze how postoperative complications for obese patients with SAH differ by the treatment modality used for aneurysm repair. METHODS Clinical data for adult patients with SAH who underwent microsurgical or endovascular aneurysm repair were extracted from the Nationwide Inpatient Sample (NIS). The body habitus of patients was classified as nonobese (body mass index [BMI] < 30 kg/m²), obese (BMI ≥ 30 kg/m² and ≤ 40 kg/m²), or morbidly obese (BMI > 40 kg/m²). Multivariable logistic regression analyzed the association of body habitus with in-hospital mortality rate, complications, discharge disposition, and poor outcome as defined by the composite NIS-SAH outcome measure. Covariates included patient demographics, comorbidities (including hypertension and diabetes), health insurance status, the NIS-SAH severity scale, treatment modality used for aneurysm repair, and hospital characteristics. RESULTS In total, data from 18,281 patients were included in this study; the prevalence of morbid obesity increased from 0.8% in 2002 to 3.5% in 2011. Obese and morbidly obese patients were significantly younger and had a greater number of comorbidities than nonobese patients (p < 0.001). Mortality rates for obese (11.5%) and morbidly obese patients (10.5%) did not significantly differ from those for nonobese patients (13.5%); likewise, no differences in neurological complications or poor outcome were observed among these 3 groups. Morbid obesity was associated with significantly increased odds of several medical complications, including venous thromboembolic (OR 1.52, 95% CI 1.01-2.30, p = 0.046) and renal (OR 1.64, 95% CI: 1.11-2.43, p = 0.01) complications and infections (OR 1.34, 95% CI 1.08-1.67, p = 0.009, attributable to greater odds of urinary tract and surgical site infections). Moreover, morbidly obese patients had higher odds of a nonroutine hospital discharge (OR 1.33, 95% CI 1.03-1.71, p = 0.03). Patients with milder obesity had decreased odds of some medical complications, including cardiac, pulmonary, and infectious complications, primarily among patients who had undergone coil embolization. CONCLUSIONS In this study involving a nationwide administrative database, milder obesity was not significantly associated with increased mortality rates, neurological complications, or poor outcomes after SAH. Morbid obesity, however, was associated with increased odds of venous thromboembolic, renal, and infectious complications, as well as of a nonroutine hospital discharge. Notably, milder obesity was associated with decreased odds of some medical complications, primarily in patients treated with coiling.

Prognosis Predicting Score for Endovascular Treatment of Aneurysmal Subarachnoid Hemorrhage: A Risk Modeling Study for Individual Elderly Patients

The elderly patients with aneurysmal subarachnoid hemorrhage (aSAH) have a greater risk of poor clinical outcome after endovascular treatment (EVT) than younger patients do. Hence, it is necessary to explore which factors are associated with poor outcome and develop a predictive score specifically for elderly patients with aSAH receiving EVT. The aim of this study was to develop and validate a predictive score for 1-year outcomes in individual elderly patients with aSAH underwent EVT.In this 10-year prospective study, 520 consecutive aSAH elderly (age ≥ 60 years) patients underwent EVT in a single center were included. The risk factors, periprocedural, and 1-year follow-up data of all patients were entered in a specific prospective database. The modified Rankin scale was used for evaluating clinical outcome. To optimize the model's predictive capacity, the original matrix was randomly divided in 2 submatrices (learning and testing). The predictive score was developed using Arabic numerals for all variables based on the variable coefficients (β) of multivariable logistic regression analysis in the learning set and the predictive performance evaluation was assessed in the testing set. The risk classes were constructed using classification criteria based on sensitivity and specificity. The poor outcome rate at 1 year was 26.15%. Six risk factors, including age, hypertension, Hunt-Hess scale, Fisher scale, aneurysm location, and periprocedural complications, were independently associated with poor outcome and assembled the Changhai score. The discriminative power analysis with the area under the receiver operating characteristic curve (AUC) of the Changhai score was statistically significant (0.864, 0.824-0.904, P < 0.001). The sensitivity and specificity of the Changhai score were 82.07% and 78.06%, respectively. Our study indicated that age, hypertension, Hunt-Hess scale, Fisher scale, aneurysm location, and periprocedural complications were independent risk factors of poor outcome for elderly aSAH patients underwent EVT. In combination with these risk factors, the Changhai score can be a useful tool in the prediction of clinical outcome but needs to be validated in various centers before it can be recommended for application.