Recent Trends in Electively Treated Unruptured Intracranial Aneurysms

Nationwide trends in intensive care unit utilization in the elective endovascular treatment of unruptured intracranial aneurysms

OBJECTIVE

Multiple studies suggest routine post-operative intensive care unit (ICU) stays after endovascular treatment (EVT) of unruptured intracranial aneurysms (UIAs) is unnecessary, though rates of ICU utilization nationwide are unknown. We aim to evaluate rates and characteristics of ICU utilization in patients undergoing elective endovascular repair of UIAs.

METHODS

This is a retrospective cohort study utilizing a nationwide private-payer database in the United States to evaluate the ICU utilization in patients undergoing elective endovascular repair of UIAs between 2005 and 2019. Demographics and pre-operative comorbidities as well as post-procedural complications and discharge status were compared. An analysis of charges and costs was also performed.

RESULTS

Among 6218 patients who underwent elective EVT of a UIA, 4890 (78.6%) were admitted to the ICU post-operatively. There were no differences in age, sex, or Charlson comorbidity scores in patients admitted to the ICU post-operatively compared to those admitted elsewhere. ICU utilization was more common in urban locations compared to rural. 12.7% of patients had ICU-specific needs sufficient to be billed by a critical care provider. Total provider costs were significantly higher in patients utilizing the ICU post-operatively, even among uncomplicated patients with routine discharges.

CONCLUSION

Most patients undergoing elective endovascular UIA repair in the United States are admitted to the ICU postoperatively. Only 12.7% have ICU needs, and these patients are predictable from pre-operative characteristics or peri-operative complications. Reducing ICU use in this subgroup of patients may be an important target to improve healthcare value in this patient population.

Endovascular trends in the treatment of intracranial aneurysms in a Peruvian reference center

Objectives

Endovascular treatment of intracranial aneurysms (IAs) has evolved in recent years and is currently the preferred treatment worldwide. We analyzed the trends in the number of patients, number of aneurysms, aneurysm characteristics, and techniques used in a pure endovascular cohort of patients treated in a reference center.

Materials and Methods

Between 2010 and 2020, a retrospective data collection of patients who underwent endovascular intervention of IAs was performed. We used the Mann-Kendal test to evaluate the trends. In addition, the moving-average technique was used to assess smoother curves.

Results

Eight hundred and forty-five aneurysms were treated in 765 patients, the mean age was 53.9 ± 14.6 years and 81% were women. The number of patients (P = 0.016) and aneurysms (P = 0.003) increased significantly. Unruptured (P = 0.029) and posterior communicating artery aneurysms increased their frequency of treatment (P = 0.042). Balloon remodeling (P = 0.01) and the use of flow diverters showed a positive trend (P = 0.016).

Conclusion

There have been an increased number of patients and aneurysms treated endovascularly at our institution, including unruptured and posterior communicating aneurysms. Advanced endovascular techniques also increased. Comparative studies including surgical cases must be done in our region to determine the best approach.

Surveillance of Unruptured Intracranial Aneurysms: Cost-Effectiveness Analysis for 3 Countries

BACKGROUND AND OBJECTIVES

No consensus exists on adequate surveillance of conservatively managed unruptured intracranial aneurysms (UIAs). We aimed to determine optimal MRI surveillance strategies for the growth of UIAs using cost-effectiveness analysis. A secondary aim was to develop a clinical tool for personalizing UIA surveillance.

METHODS

We designed a microsimulation model from a health care perspective simulating 100,000 55-year-old women to estimate costs and quality-adjusted life years (QALYs) over a lifetime horizon in the United States, the United Kingdom, and the Netherlands, using literature-derived model parameters. Country-specific costs and willingness-to-pay thresholds ($100,000/QALY for the United States, £30,000/QALY for the United Kingdom, and €80,000/QALY for the Netherlands) were used. Lifetime costs and QALYs were annually discounted at 3% for the United States, 3.5% for the United Kingdom, or 4% (costs) and 1.5% (QALYs) for the Netherlands. Strategies were no follow-up surveillance, follow-up with MRI in the first and fifth year after UIA discovery, every 5 years, every 2 years, or annually, or immediate intervention (i.e., clipping or coiling). Using the microsimulation model, we developed a tool for personalizing UIA surveillance for men and women, with different ages and varying aneurysm characteristics. Uncertainty in the input parameters was modeled with probabilistic sensitivity analysis.

RESULTS

Among 55-year-old women, 2,222 individuals in the United States, 1,910 in the United Kingdom, and 2,040 in the Netherlands needed to undergo an annual MRI scan to prevent 1 case of subarachnoid hemorrhage per year. No surveillance MRI was most cost-effective in the United States (in 47% of the simulations) and United Kingdom (in 54% of simulations), whereas annual MRI was most cost-effective in the Netherlands (in 53% of simulations). In the United States and United Kingdom, annual surveillance or surveillance in the first and fifth year after discovery was cost-effective in patients <60 years and at increased risk of aneurysm growth. The optimal, personalized, surveillance strategies were summarized in a look-up table for use in clinical practice.

DISCUSSION

Generally, the US and UK physicians should refrain from assigning patients, particularly older patients and those with few risk factors for aneurysm growth or rupture, to frequent MRI surveillance. In the Netherlands, annual follow-up is generally most cost-effective.

Unruptured cerebral aneurysm risk stratification: Background, current research, and future directions in aneurysm assessment

Background:

The optimal management of unruptured cerebral aneurysms is widely debated in the medical field. Rapid technology advances, evolving understanding of underlying pathophysiology, and shifting practice patterns have made the cerebrovascular field particularly dynamic in recent years. Despite progress, there remains a dearth of large randomized studies to help guide the management of these controversial patients.

Methods:

We review the existing literature on the natural history of unruptured cerebral aneurysms and highlight ongoing research aimed at improving our ability to stratify risk in these patients.

Results:

Landmark natural history studies demonstrated the significance of size, location, and other risk factors for aneurysm rupture, but prior studies have significant limitations. We have begun to understand the underlying pathophysiology behind aneurysm formation and rupture and are now applying new tools such as flow dynamics simulations and machine learning to individualize rupture risk stratification.

Conclusion:

Prior studies have identified several key risk factors for aneurysmal rupture, but have limitations. New technology and research methods have enabled us to better understanding individual rupture risk for patients with unruptured cerebral aneurysms.

Assessing the rate, natural history, and treatment trends of intracranial aneurysms in patients with intracranial dural arteriovenous fistulas: a Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) investigation

OBJECTIVE

There is a reported elevated risk of cerebral aneurysms in patients with intracranial dural arteriovenous fistulas (dAVFs). However, the natural history, rate of spontaneous regression, and ideal treatment regimen are not well characterized. In this study, the authors aimed to describe the characteristics of patients with dAVFs and intracranial aneurysms and propose a classification system.

METHODS

The Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database from 12 centers was retrospectively reviewed. Analysis was performed to compare dAVF patients with (dAVF+ cohort) and without (dAVF-only cohort) concomitant aneurysm. Aneurysms were categorized based on location as a dAVF flow-related aneurysm (FRA) or a dAVF non-flow-related aneurysm (NFRA), with further classification as extra- or intradural. Patients with traumatic pseudoaneurysms or aneurysms with associated arteriovenous malformations were excluded from the analysis. Patient demographics, dAVF anatomical information, aneurysm information, and follow-up data were collected.

RESULTS

Of the 1077 patients, 1043 were eligible for inclusion, comprising 978 (93.8%) and 65 (6.2%) in the dAVF-only and dAVF+ cohorts, respectively. There were 96 aneurysms in the dAVF+ cohort; 10 patients (1%) harbored 12 FRAs, and 55 patients (5.3%) harbored 84 NFRAs. Dural AVF+ patients had higher rates of smoking (59.3% vs 35.2%, p < 0.001) and illicit drug use (5.8% vs 1.5%, p = 0.02). Sixteen dAVF+ patients (24.6%) presented with aneurysm rupture, which represented 16.7% of the total aneurysms. One patient (1.5%) had aneurysm rupture during follow-up. Patients with dAVF+ were more likely to have a dAVF located in nonconventional locations, less likely to have arterial supply to the dAVF from external carotid artery branches, and more likely to have supply from pial branches. Rates of cortical venous drainage and Borden type distributions were comparable between cohorts. A minority (12.5%) of aneurysms were FRAs. The majority of the aneurysms underwent treatment via either endovascular (36.5%) or microsurgical (15.6%) technique. A small proportion of aneurysms managed conservatively either with or without dAVF treatment spontaneously regressed (6.2%).

CONCLUSIONS

Patients with dAVF have a similar risk of harboring a concomitant intracranial aneurysm unrelated to the dAVF (5.3%) compared with the general population (approximately 2%-5%) and a rare risk (0.9%) of harboring an FRA. Only 50% of FRAs are intradural. Dural AVF+ patients have differences in dAVF angioarchitecture. A subset of dAVF+ patients harbor FRAs that may regress after dAVF treatment.

Risk Factors Associated with ICU-Specific Care in Patients Undergoing Endovascular Treatment of Unruptured Intracranial Aneurysms

BACKGROUND

Multiple studies suggest routine postoperative intensive care unit (ICUs) stays in presumed high-risk neurosurgical procedures may be unnecessary. Our objective was to evaluate the risk factors associated with ICU-specific needs in patients undergoing elective endovascular treatment of unruptured intracranial aneurysms.

METHODS

A retrospective review of consecutive patients undergoing elective endovascular treatment of unruptured aneurysms was performed between January 2010 and January 2020 in a single academic medical center. Patient demographic information, aneurysm and treatment characteristics, intraoperative and postoperative complications, as well as ICU-specific needs, were abstracted. The primary outcome was ICU-specific needs.

RESULTS

A total of 382 patient encounters in 344 unique patients were abstracted. 13.6% (52 of 382) of patient encounters had an ICU-specific need. Multivariate analysis revealed that age [adjusted odds ratio (OR) 1.04, 95% confidence interval (CI) 1.01-1.07, p = 0.03], procedure duration greater 200 min (adjusted OR 2.75, 95% CI 1.34-5.88, p = 0.007), and any intraoperative complication (adjusted OR 20.41, CI 7.97-56.57, p < 0.001) were independent predictors of postoperative ICU-specific needs. The majority of ICU-specific needs (94%, 49 of 52) occurred within 6 h of surgery.

CONCLUSIONS

Our results show that age, procedure duration greater than or equal to 200 min, and intraoperative complication were independent predictors of postoperative ICU-specific needs in patients presenting for elective endovascular treatment of unruptured intracranial aneurysms. The majority of ICU-specific needs and associated complications occurred in the immediate postoperative period. This data can be used to help decide the appropriate postoperative level of care in this patient population.

What is the role of neurosurgeons in the current management of intracranial aneurysm in France? An analysis of professional practices

STUDY DESIGN

Retrospective observational survey-based study.

INTRODUCTION

In France, intracranial aneurysm (IA) patients are managed by neurosurgeons and by interventional neuroradiologists. The growth of endovascular treatment led us to reflect on the role of neurosurgeons in the management of patients with IA. The present study aimed to highlight the current organization of IA management in France.

METHOD

A 60-question survey was sent to the neurosurgeons in 34 hospitals managing IA patients. Thirty-three questions dealt with standards of care, follow-up procedures and the involvement of the specific specialist.

RESULTS

Twenty-seven centers (79.4%) responded to the survey. A Vascular Multidisciplinary Discussion Team was organized, including both surgeons and neuroradiologists, in 92% of responding centers. There were department protocols in 66% of centers, a local registry in 33% and clinical trials in IA in 60%. Patients with unruptured IA were first seen by a neurosurgeon or by an interventional neuroradiologist, with different practices. For ruptured IA, the neurosurgeons were contacted first in 93% of cases, and were systematically involved in initial intensive care unit management. The patients were hospitalized in the neurosurgery department in 89% of the centers. The neurosurgeons took care of initial follow-up in 85% of the centers, and of lifetime follow-up in 36%. In most centers, radiological monitoring of IA was based on MRI angiography for patients who were embolized or under surveillance, and on CT angiography after microsurgery.

CONCLUSION

Despite the growth of endovascular treatments, the present survey and the literature highlight a major role of neurosurgeons in treatment, follow-up and care coordination.

Readmission Trends Related to Unruptured Intracranial Aneurysm Treatment

Background and Purpose: Aneurysmal subarachnoid hemorrhage (SAH) is associated with high mortality. Prophylactic treatment of the unruptured intracranial aneurysm (UIA) is considered in a select group of patients thought to be at high for aneurysmal rupture. Hospital readmission rates can serve as a surrogate marker for the safety and cost-effectiveness of treatment options for UIAs; we present an analysis of the 30-day rehospitalization rates and predictors of readmission following UIA treatment with surgical and endovascular approaches. Methods: We retrospectively analyzed data from the National Readmission Database (NRD) derived from the Healthcare Cost and Utilization Project for the year 2014. The cohort included patients with a primary discharge diagnosis of a treated unruptured aneurysm. The primary outcome variable was the 30-day readmission rate in open surgical vs. endovascularly treated groups. The secondary outcomes included predictors of readmissions, and causes of 30-day readmissions in these two groups. Results: The 30-day readmission rate for the surgical group was 8.37% compared to 4.87% for the endovascular group. The index hospitalization duration was longer in the surgical group. A larger proportion of the patients readmitted following surgical treatment were hypertensive (76.35, vs. 63.43%), but the prevalence of other medical comorbidities was comparable in the two treatment groups. Conclusions: There is a higher likelihood for 30-day readmission, longer duration of initial hospitalization and a lower likelihood of discharge home following surgical treatment of UIAs when compared to endovascular treatment. These findings, however, do not demonstrate long-term superiority of one specific treatment modality.

Predictors of Extended Length of Stay Following Treatment of Unruptured Adult Cerebral Aneurysms: A Study of The National Inpatient Sample

BACKGROUND

In an unprecedented era of soaring healthcare costs, payers and providers alike have started to place increased importance on measuring the quality of surgical procedures as a surrogate for operative success. One metric used is the length of hospital stay (LOS) during index admission. For the treatment of unruptured cerebral aneurysms, the determinants of extended length of stay are relatively unknown. The aim of this study was to identify the patient- and hospital-level factors associated with extended LOS following treatment for unruptured cerebral aneurysms.

METHODS

The National Inpatient Sample years 2010 - 2014 was queried. Adults (≥18 years) with unruptured aneurysms undergoing either clipping or coiling were selected using the International Classification of Diseases, Ninth Revision, Clinical Modification coding system. Extended LOS was defined as greater than 75^th percentile for the entire cohort (>5 days). Weighted patient demographics, comorbidities, complications, LOS, disposition and total cost were recorded. Multivariate logistic regression was used to determine the odds ratio for risk-adjusted extended LOS. The primary outcome was the degree which patient comorbidities or postoperative complications correlated with extended LOS.

RESULTS

A total of 46,880 patients were identified for which 9,774 (20.8%) patients had extended LOS (Normal LOS: 37,106; Extended LOS: 9,774). Patients in the extended LOS cohort presented with a greater number of comorbidities compared to the normal LOS cohort. A greater proportion of the normal LOS cohort was coiled (Normal LOS: 63.0% vs. Extended LOS: 33.5%, P<0.001), while more patients in the extended LOS cohort were clipped (Normal LOS: 37.0% vs. Extended LOS: 66.5%, P<0.001). The overall complication rate was higher in the extended LOS cohort (Normal LOS: 7.3% vs. Extended LOS: 43.8%, P<0.001). On average, the extended LOS cohort incurred a total cost nearly twice as large (Normal LOS: $26,050 ± 13,430 vs. Extended LOS: $52,195 ± 37,252, P<0.001) and had more patients encounter non-routine discharges (Normal LOS: 8.5% vs. Extended LOS: 52.5%, P<0.001) compared to the normal LOS cohort. On weighted multivariate logistic regression, multiple patient-specific factors were associated with extended LOS. These included demographics, preadmission comorbidities, choice of procedure, and inpatient complications. The odds ratio for extended LOS was 5.14 (95% CI, 4.30 - 6.14) for patients with 1 complication and 19.58 (95% CI, 15.75 - 24.34) for patients with > 1 complication.

CONCLUSIONS

Our study demonstrates that extended LOS after treatment of unruptured aneurysms is influenced by a number of patient-level factors including demographics, preadmission comorbidities, type of aneurysm treatment (open surgical versus endovascular), and, importantly, inpatient complications. A better understanding of these independent predictors of prolonged length of hospital stay may help to improve patient outcomes and decrease overall healthcare costs.

Impact of Ruptured Aneurysm Circulation on Mortality: A Nationwide Inpatient Sample Analysis

OBJECTIVE

This study investigates the effect of aneurysm circulation on mortality and patient outcomes after aneurysmal subarachnoid hemorrhage (SAH) within the United States.

METHODS

A retrospective cohort study was conducted using the Nationwide Inpatient Sample (NIS), a part of the Healthcare Cost and Utilization Project (HCUP), with ICD-10 codes for non-traumatic SAH between 2015-2016. Aneurysms were stratified as either anterior or posterior circulation. Multivariate logistic regression was used to find the impact of selected variables on the odds of mortality.

RESULTS

The NIS reported 1,892 cases of non-traumatic SAH within the study period that were predominantly anterior circulation (82.6%), female (68.6%), white (57.7%), with mean age of 59.07 years, and in-hospital mortality of 21.4%. Anterior circulation aneurysms were associated with lower severity of initial illness (p = 0.014) but higher likelihood of vasospasm (p = 0.0006) than those of the posterior circulation. In a multivariate logistic regression analysis, mortality was associated with posterior circulation aneurysms (OR: 1.42; CI 95% 1.005-20.10, p = 0.047), increasing age (OR: 1.035; 95% CI 1.022-1.049; p < 0.0001), and shorter hospital stays (OR: 0.7838; 95% CI 0.758-0.811; p < 0.0001). Smoking history (OR: 0.825; 95% CI 0.573-1.187, p > 0.05) and vasospasm (OR: 1.005; 95% CI 0.648-1.558; p > 0.05) were not significantly associated with higher odds of mortality.

CONCLUSIONS

Mortality following aneurysmal SAH is associated with posterior circulation aneurysms, and increasing age, but not smoking history or vasospasm. These findings may be useful for prognostication and counseling patients and families.

Treatment and diagnosis of cerebral aneurysms in the post-International Subarachnoid Aneurysm Trial (ISAT) era: trends and outcomes

BACKGROUND

Following publication of the International Subarachnoid Aneurysm Trial (ISAT), treatment paradigms for cerebral aneurysms (CAs) shifted from open surgical clipping to endovascular embolization as primary therapy in a majority of cases. However, comprehensive analyses evaluating more recent CA diagnosis patterns, patient populations and outcomes as a function of treatment modality remain rare.

METHODS

The National Inpatient Sample from 2004 to 2014 was reviewed. Aneurysmal subarachnoid hemorrhages (aSAHs) and unruptured intracranial aneurysms (UIAs) with a treatment of surgical clipping or endovascular therapy (EVT) were identified. Time trend series plots were created. Linear and logistic regressions were utilized to quantify treatment changes.

RESULTS

114 137 aSAHs and 122 916 UIAs were reviewed. aSAH (+732/year, p=0.014) and UIA (+2550/year, p<0.0001) discharges increased annually. The annual caseload of surgical clippings for aSAH decreased (-264/year, p=0.0002) while EVT increased (+366/year, p=0.0003). For UIAs, the annual caseload for surgical clipping remained stable but increased for EVT (+615/year, p<0.0001). The rate of incidentally diagnosed UIAs increased annually (+1987/year; p<0.0001). Inpatient mortality decreased for clipping (p<0.0001) and EVT in aSAH (p<0.0001) (2004 vs 2014-clipping 13% vs 11.7%, EVT 15.8% vs 12.7%). Mortality rates for clipped UIAs decreased over time (p<0.0001) and remained stable for EVT (2004 vs 2014-clipping 1.57% vs 0.40%, EVT 0.59% vs 0.52%).

CONCLUSION

Ruptured and unruptured CAs are increasingly being treated with EVT over clipping. Incidental unruptured aneurysm diagnoses are increasing dramatically. Mortality rates of ruptured aneurysms are improving regardless of treatment modality, whereas mortality in unruptured aneurysms is only improving for surgical clipping.