Kallmes, David F.

Background and purpose A recent expansion of the neurointerventional workforce in the USA could lead to a trend toward cerebral aneurysms being increasingly treated at low volume centers. Such a trend could have a negative impact on patient care as higher volume centers are known to have better outcomes. Methods Using the Nationwide Inpatient Sample, we evaluated trends in aneurysm treatment in the USA from 2001 to 2010. Annual volumes of both ruptured and unruptured aneurysms were counted, as well as annual percentages of cases treated at high volume centers (≥50 aneurysms/year clipped or coiled). Results The number of ruptured aneurysms treated per year has fluctuated between 9000 and 12 000 from 2003 to 2010. In 2001–2002, 27.4% of intracranial aneurysm patients were treated with clipping or coiling at high volume centers, with a peak of 70.1% in 2007–2008. This proportion dropped to 61.8% in 2009–2010. The proportion of patients clipped at high volume centers was 23.3% in 2001–2002 and peaked at 65.0% in 2007–2008. In 2009–2010, the proportion dropped to 58.6%. For coiling patients, 46.4% were treated at high volume centers in 2001–2002, with a peak of 70.1% in 2007–2008, and a drop to 61.8% in 2009–2010. Conclusion A trend toward less cerebral aneurysms being treated in high volume centers in 2009 and 2010 is worrisome because high volume centers are known to tend to have better outcomes. This trend is likely due to recent expansion of the neurointerventional workforce.

Background and Purpose— Acute intraprocedural thrombus formation complicating endovascular cerebral aneurysm treatment is often treated with intra-arterial or intravenous administration of thrombolytic agents or glycoprotein IIb/IIIa (GpIIb/IIIa) inhibitors. We sought to evaluate the morbidity and mortality associated with such treatments using a large multihospital database. Methods— Using the Premier Perspective Database, we examined outcomes for patients receiving endovascular coiling for ruptured and unruptured aneurysms requiring rescue therapy, defined as treatment with GpIIb/IIIa inhibitors and fibrinolytic therapy. We compared discharge status, length of stay, and complication rates across 3 groups: (1) patients receiving GpIIb/IIIa inhibitors only, (2) patients receiving fibrinolytic therapy only, and (3) patients receiving both GpIIb/IIIa inhibitors and fibrinolytics. Student t test was used to compare continuous variables, and Fisher exact test was used to compare categorical variables. Results— Seven-percent (254/3627) of patients treated for unruptured aneurysms received rescue therapy. When compared with patients receiving GpIIb/IIIa inhibitors alone, patients receiving only fibrinolytics had significantly higher rates of discharge to institutions other than home (37.5% [9/24] versus 7.4% [15/201]; P <0.0001). Eight-percent of patients (338/4204) treated for ruptured aneurysms received rescue therapy. When compared with patients receiving GpIIb/IIIa inhibitors alone, patients receiving only fibrinolytics had significantly higher rates of mortality (26.0% [18/69] versus 14.5% [35/241]; P =0.02) and discharge to institutions other than home (59.4% [41/69] versus 36.5% [88/241]; P <0.0001). Conclusions— Pharmacological rescue therapy occurred in 7% to 8% of endovascular coiling patients with unruptured and ruptured intracranial aneurysms. Rescue therapy with thrombolytic agents resulted in significantly more morbidity and mortality than rescue therapy with GpIIb/IIIa inhibitors.

Objectives The phrase ‘Initial Clinical Experience' in a manuscript's title implies that the described technique offers promise of future clinical relevance. We assessed, using rates of subsequent citations, the actual academic relevance of such articles in comparison to articles not containing the phrase. Design We searched ISI database for articles that included the studied phrase in their titles between 1975 and 2009 and grouped the results by the related medical specialty. We excluded articles from journals with no available impact factor. For each identified article, we extracted number of included patients, citations/year, the average impact factor of the publishing journal over the last five years and the proportion of articles published in the same journal that garnered zero subsequent citations. Setting Retrospective review of a scientific database. Participants None Main outcome measures Citation rate Results Among a total of 982,127 articles published in 186 journals representing eight major publishing medical specialties, 531 (0.05%) were Initial Clinical Experience articles. Thirty percent of Initial Clinical Experience articles were never cited compared with 7% of the overall article volume ( p < 0.0001). Citations/year for Initial Clinical Experience articles were significantly lower than the median impact factor ( p < 0.0001). There was no correlation between citations and number of patients described in the Initial Clinical Experience articles ( p = 0.61). Conclusions Initial Clinical Experience articles are cited less frequently than the average, especially in Cardiovascular, Radiology and Ophthalmology journals.

We present a computational fluid dynamics (CFD) analysis of the hemodynamic environment of an anterior communicating artery that spontaneously ruptured immediately following three-dimensional rotational angiography. Subsequent digital subtraction angiography allowed for the localization of the point of rupture within the aneurysm dome. CFD analysis demonstrated a concentrated jet that impinged directly at the site of rupture. Peak systolic pressure and wall shear stress were both maximal near the rupture location.

Background and Purpose— Endovascular therapy has increasingly become the most common treatment for unruptured cerebral aneurysms in the United States. We evaluated a national, multi-hospital database to examine recent utilization trends and compare periprocedural outcomes between clipping and coiling treatments of unruptured aneurysms. Methods— The Premier Perspective database was used to identify patients hospitalized between 2006 to 2011 for unruptured cerebral aneurysm who underwent clipping or coiling therapy. A logistic propensity score was generated for each patient using relevant patient, procedure, and hospital variables, representing the probability of receiving clipping. Covariate balance was assessed using conditional logistic regression. Following propensity score adjustment using 1:1 matching methods, the risk of in-hospital mortality and morbidity was compared between clipping and coiling cohorts. Results— A total of 4899 unruptured aneurysm patients (1388 clipping, 3551 coiling) treated at 120 hospitals were identified. Following propensity score adjustment, clipping patients had a similar likelihood of in-hospital mortality (odds ratio [OR], 1.43; 95% confidence interval [CI], 0.49–4.44; P =0.47) but a significantly higher likelihood of unfavorable outcomes, including discharge to long-term care (OR, 4.78; 95% CI, 3.51–6.58; P <0.0001), ischemic complications (OR, 3.42; 95% CI, 2.39–4.99; P <0.0001), hemorrhagic complications (OR, 2.16; 95% CI, 1.33–3.57; P <0.0001), postoperative neurological complications (OR, 3.39; 95% CI, 2.25–5.22; P <0.0001), and ventriculostomy (OR, 2.10; 95% CI, 1.01–4.61; P =0.0320) compared with coiling patients. Conclusions— Among patients treated for unruptured intracranial aneurysms in a large sample of hospitals in the United States, clipping was associated with similar mortality risk but significantly higher periprocedural morbidity risk compared with coiling.

Background and Purpose— Although thrombolysis in cerebral infarction (TICI) 2b/3 has been regarded as a successful angiographic outcome, the definition or subclassification of TICI 2 has differed between the original (o-TICI) and modified TICI (m-TICI). We sought to compare interobserver variability for both scores and analyze the subgroups of the TICI 2. Methods— Five readers interpreted angiographies independently using a 6-point scale as follows: grade 0, no antegrade flow; grade 1, flow past the initial occlusion without tissue reperfusion; grade 2, partial reperfusion in <50% of the affected territory; grade 3, partial reperfusion in 50% to 66%; grade 4, partial reperfusion in ≥67%; grade 5, complete perfusion. Readings using this scale were then converted into o-TICI and m-TICI score. Statistical analysis was performed according to TICI 2 subgroups. Results— Interobserver agreement was good for the o-TICI and m-TICI scores (intraclass correlation coefficient, 0.73 and 0.67, respectively). Our grade 3 (partial perfusion with 50% to 66%) occupied 19% of total readings, which would have been classified as grade 2a in o-TICI, but as 2b in m-TICI. The m-TICI was more likely to predict good clinical outcome than o-TICI (odds ratio, 2.01 versus 1.63, in reads with TICI 2b/3 versus 0/2a). Conclusions— Both TICI scales showed good agreement among readers. However, the variability in partial perfusion thresholds leads to different grading in ≈20% of cases and may result in significantly different rates of accurate outcome prediction.

Object The presence of a “July effect,” where the influx of new residents and fellows at teaching hospitals every July may negatively affect patient care and outcomes, is widely debated. The authors used the Nationwide Inpatient Sample (NIS) to identify all cases of spinal surgery and examine outcomes among patients who underwent surgery in July compared with those who underwent surgery in other months. Methods Spinal surgery hospitalizations from 2001 to 2008 were identified in the NIS by extracting relevant ICD-9 codes. Rates of in-hospital mortality, discharge to a long-term care facility, and postoperative complications were compared between admission months and between teaching and nonteaching hospitals using the Wilcoxon rank-sum test, Fisher exact test, and multivariate regression analysis. Results Compared with patients admitted in other months, patients who were admitted to teaching hospitals in July for spinal surgery showed a similar likelihood of in-hospital mortality (OR 0.94 [95% CI 0.78–1.11], p = 0.46), reaction to implanted device/instrumentation (OR 0.88 [95% CI 0.77–1.02], p = 0.09), and postoperative wound dehiscence (OR 1.12 [95% CI 0.94–1.33], p = 0.25). A significantly higher likelihood of discharge to a long-term care facility (OR 1.03 [95% CI 1.00–1.07], p = 0.0467) and postoperative infection (OR 1.11 [95% CI 1.05–1.17], p = 0.0341) was observed in teaching hospitals in July compared with other months; however, incidence rates were similar regardless of admission month. Higher-risk patients (Charlson score ≥ 2) admitted to teaching hospitals in July had a similar likelihood of all outcomes regardless of admission month. Conclusions This study of nationwide hospitalizations demonstrates that the influx of new residents and fellows in July has a negligible effect on periprocedural outcomes following spinal surgery.

Background and objective Sacroplasty has emerged as a treatment option for patients with painful osteoporotic sacral insufficiency fractures. We report short-term outcomes in a consecutive cohort of patients treated with sacroplasty. Methods We retrospectively reviewed 57 patients treated with sacroplasty for painful osteoporotic sacral fractures at our institution between 2004 and 2011. An 11-point numerical rating scale pain score was recorded at rest and at activity pre- and post-procedure. Opioids prescribed to the patient both pre- and post-procedure were recorded. Results Mean duration of pain prior to sacroplasty was 3 weeks (IQR 2–5). Procedural complications were minimal. Median post-procedure follow-up time was 2.5 weeks (IQR 1–5) among 45 patients with available data. Thirty-seven (82%) of the 45 patients experienced a numerical or descriptive decrease from initial pain at follow-up. Median activity pain scores collected from 13 patients decreased from 10 (IQR 8.5–10) pre-procedure to 6 (IQR 4–6.8) post-procedure (p<0.0001), and median rest pain scores collected from 29 patients decreased from 7 (IQR 4–8.5) to 2 (IQR 1–3.5)(p<0.0001). Twenty-two (76%) of 29 patients had at least a 30% decrease in rest pain scores. The median number of opioids prescribed per patient decreased from 1 (IQR 1–2) pre-procedure to 0 (IQR 0–1) post-procedure (p<0.0001). Thirty-four of 57 patients (60%) had decreased opioid usage, 15 (26%) patients had unchanged usage and 8 (14%) had increased usage. Conclusions Our series demonstrates that sacroplasty is a safe and effective treatment in patients with painful osteoporotic insufficiency fractures.

Stimulated by a recent controversy regarding pressure drops predicted in a giant aneurysm with a proximal stenosis, the present study sought to assess variability in the prediction of pressures and flow by a wide variety of research groups. In phase I, lumen geometry, flow rates, and fluid properties were specified, leaving each research group to choose their solver, discretization, and solution strategies. Variability was assessed by having each group interpolate their results onto a standardized mesh and centerline. For phase II, a physical model of the geometry was constructed, from which pressure and flow rates were measured. Groups repeated their simulations using a geometry reconstructed from a micro-computed tomography (CT) scan of the physical model with the measured flow rates and fluid properties. Phase I results from 25 groups demonstrated remarkable consistency in the pressure patterns, with the majority predicting peak systolic pressure drops within 8% of each other. Aneurysm sac flow patterns were more variable with only a few groups reporting peak systolic flow instabilities owing to their use of high temporal resolutions. Variability for phase II was comparable, and the median predicted pressure drops were within a few millimeters of mercury of the measured values but only after accounting for submillimeter errors in the reconstruction of the life-sized flow model from micro-CT. In summary, pressure can be predicted with consistency by CFD across a wide range of solvers and solution strategies, but this may not hold true for specific flow patterns or derived quantities. Future challenges are needed and should focus on hemodynamic quantities thought to be of clinical interest.