Citations

Objective A study was undertaken to estimate the fraction of intracranial aneurysms that might be amenable to treatment with the pipeline embolization device (PED), a current flow diverter device, and to determine the types of aneurysms that are probably not amenable to treatment with this device. Methods A retrospective analysis of 200 consecutive intracranial aneurysms as seen on three-dimensional rotational angiography images was conducted. Based on aneurysm and parent artery morphology, four independent observers experienced in the use of the PED judged the likelihood that a given aneurysm could theoretically be treated with one or more PED using a 5-point scale: grades 1 and 2 indicated amenability to treatment with multiple devices; grade 3 indicated amenability to treatment with one device; and grades 4 and 5 indicated the aneurysm would not be amenable to treatment with the PED. Aneurysms were analyzed on the basis of anatomical factors only. Rupture status was not considered. Interobserver agreement was determined. Results 94 of 200 aneurysms (47%) were judged to be likely to be amenable to treatment with the PED; 50 cases (25%) were judged to be amenable to the use of multiple overlapping devices while, in 44 cases (22%), coverage with a single device was preferred. There was a significant relationship between the location of the aneurysm and the grade of the aneurysm (p<0.0001). Conclusion On the basis of anatomical configuration, nearly half of the aneurysms in this study were likely to be amenable to treatment with the PED.

Object The management of incidental small unruptured intracranial aneurysms (UIAs) is controversial and many factors need to be considered in the decision-making process. The authors describe a large consecutive series of patients harboring small incidental intracranial aneurysms. Treatment strategy, natural history, complications, and short-term outcomes are presented. Methods Between January 2008 and May 2011, the authors prospectively evaluated 212 patients with 272 small (< 10-mm) incidental aneurysms. Treatment recommendations (observation, endovascular treatment, or surgery), complications of treatment, and short-term outcomes were assessed. Results Recommended treatment consisted of observation in 125 patients, endovascular embolization in 64, and surgery in 18. Six patients were excluded from further analysis because they underwent treatment elsewhere. In the observation group, at a mean follow-up of 16.7 months, only 1 patient was moved to the embolization group. Seven (6%) of the 125 patients in the observation group died of causes unrelated to aneurysm. Sixty-five patients underwent 69 embolization procedures. The periprocedural permanent morbidity and mortality rates in patients undergoing endovascular treatment were 1.5% and 1.5%, respectively (overall morbidity and mortality rate 3.0%). In the surgery group no periprocedural complications were observed, although 1 patient did not return to her previous occupation. No aneurysmal rupture was documented in any of the 3 treatment groups during the follow-up period. Conclusions A cautious and individualized approach to incidental UIAs is of utmost importance for formulation of a safe and effective treatment algorithm. Invasive treatment (either endovascular or surgery) can be considered in selected younger patients, certain “higher-risk” locations, expanding aneurysms, patients with a family history of aneurysmal hemorrhage, and in those who cannot live their lives knowing that they harbor the UIA. Although the complication rate of invasive treatment is very low, it is not negligible. The study confirms that small incidental UIAs deemed to be not in need of treatment have a very benign short-term natural history, which makes observation a reasonable approach in selected patients.

Background and Purpose— It is important to know the costs of hospitalization for patients undergoing endovascular embolectomy so that comparisons can be made with payments to hospitals. Methods— Using the National Inpatient Sample, we evaluated the costs of hospitalization for patients treated with endovascular embolectomy in the United States from 2006 to 2008. The primary end point examined in this study was total hospital costs, and these were correlated with clinical outcome. Results— A total of 3864 patients received endovascular embolectomy. A total of 1649 patients were <65 years old and 2205 patients were ≥65 years old. Median hospital costs in 2008 dollars were $36 999 (interquartile range, $26 662–$56 405) for patients with good outcome, $50 628 (interquartile range, $33 135–$76 063) for patients with severe disability, and $35 109 (interquartile range, $25 053–$62 621) for patients with mortality. Conclusions— Hospitalization costs for patients treated with endovascular embolectomy are rather high, probably due to the serious nature of their illness. Medicare payments have not been adequate reimbursement for these hospitalizations.

Object The authors sought to identify the presence of a “July effect,” a transient increase in adverse outcomes during July, among a cohort of spontaneous subarachnoid hemorrhage (SAH) admissions recorded in the National Inpatient Sample (NIS). Methods The discharge status, admission month, patient demographics, treatment parameters, and hospital characteristics among spontaneous SAH admissions were extracted from the 2001–2008 NIS. Multivariate regression was used to determine whether an unfavorable discharge status and/or in-hospital mortality significantly increased in summer months in a pattern suggestive of a July effect. Additional models were generated to assess the impact of hospital teaching status on these outcomes. Results Among 57,663,486 hospital admissions from the 2001–2008 NIS, 52,879 cases of spontaneous SAH (ICD-9-CM 430) were treated at teaching (36,914 cases [70%]) and nonteaching (15,965 cases [30%]) facilities. Regression models failed to reveal a July effect for in-hospital mortality (χ2 = 0.75, p = 1.000) or unfavorable discharges (χ2 = 1.69, p = 0.999) among monthly SAH admissions, although they did suggest a significant reduction in these outcomes (in-hospital mortality, OR = 0.89, p < 0.001; unfavorable discharges, OR = 0.88, p < 0.001) among teaching hospitals as compared with nonteaching hospitals after adjustment for disparities in demographic, treatment, and hospital characteristics. Conclusions The discharge disposition among SAH admissions within the NIS was not suggestive of a July effect but did reveal that teaching institutions have significantly lower rates of adverse outcomes when compared with nonteaching hospitals. Note, however, that the origins of this difference related to teaching status remain unclear.

Object Evidence of better outcomes in patients with aneurysmal subarachnoid hemorrhage treated at higher-volume centers might be expected to result in more of these patients being referred to such centers. The authors evaluated the US National Inpatient Sample for the years 2001 to 2008 for trends in patient admissions for the treatment of ruptured aneurysms at high- and low-volume centers. Methods The authors determined the number of ruptured aneurysms treated with clipping or coiling annually at low-volume (≤ 20 patients/year) and high-volume (> 20 patients/year) centers and also counted the number of high- and low-volume centers performing each treatment. Hospitalizations for clipping or coiling ruptured aneurysms were identified by cross-matching International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes for the diagnosis of a ruptured aneurysm (ICD-9-CM 430) with procedure codes for clipping (ICD-9-CM 39.51) or coiling (ICD-9-CM 39.52, 39.79, or 39.72) cerebral aneurysms. Results In 2001, 31% (435 of 1392) of the patients who underwent clipping and 0% (0 of 122 patients) of those who underwent coiling did so at high-volume centers, whereas in 2008 these numbers increased to 62% (627 of 1016) and 68% (917 of 1351) of patients, respectively. For clipping procedures, the number of low-volume centers significantly declined from 177 in 2001 to 85 in 2008, whereas the number of high-volume centers remained constant at 13–15. For coiling procedures, the number of low-volume centers decreased from 62 in 2001 to 54 in 2008, whereas the number of high-volume centers substantially increased from 0 in 2001 to 16 in 2005 and remained constant thereafter. Conclusions The treatment of ruptured cerebral aneurysms increasingly occurs at high-volume centers in the US. This trend is favorable given that better outcomes are associated with the treatment of these lesions at high-volume centers.

Background and Purpose— Intracranial hemorrhage (ICH) is a rare and devastating complication of carotid revascularization. We sought to determine the prevalence of, type of, and risk factors associated with ICH among recipients of carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS) within the National Inpatient Sample (NIS). Methods— Postoperative cases of ICH after CEA (International Classification of Disease 9 th edition [ICD-9]: 38.12) or CAS (ICD-9: 00.63) were retrieved from the 2001 to 2008 NIS. Clinical presentation (asymptomatic versus symptomatic), discharge status, in-hospital mortality, demographics, and hospital characteristics were extracted from NIS data. Charlson indices of comorbidity were determined based on ICD-9 and clinical classification software codes. Multivariate regression was used to determine the impact of revascularization procedure type and symptom status on adverse outcomes, including ICH, in-hospital mortality, and unfavorable discharge status. Results— Among 57 663 486 NIS hospital admissions, 215 012 CEA and 13 884 CAS procedures were performed. Symptomatic presentations represented the minority of CEA (N=10 049; 5%) and CAS cases (N=1251; 10%). ICH occurred significantly more frequently after CAS than CEA in both symptomatic (4.4% versus 0.8%; P <0.0001) and asymptomatic presentations (0.5% versus 0.06%; P <0.0001). Multivariate regression suggested that symptomatic presentations (versus asymptomatic) and CAS procedures (versus CEA) were both independently predictive of 6-fold to 7-fold increases in the frequency of postoperative ICH. ICH was independently predictive in a 30-fold increased risk of mortality before discharge. Conclusions— CAS procedures are associated with elevated adverse outcomes, including ICH, in-hospital death, and unfavorable discharges, especially among symptomatic presentations.

Abstract BACKGROUND: Extradural arteriovenous malformations (AVMs) are uncommon vascular malformations of the spine. They are characterized by an arteriovenous communication (localized in the paraspinal soft tissues and the epidural venous plexus) that may have retrograde intradural venous drainage. Surgical treatment of extradural AVMs can be challenging because of the common location ventral to the dural sac and the presence of arterialized venous lakes. OBJECTIVE: To assess the effectiveness of embolization with a liquid embolic material (Onyx; ev3 Inc, Irvine, California) in 7 consecutive patients with extradural spinal AVMs and intradural venous drainage. METHODS: We retrospectively collected information regarding patient characteristics, clinical presentation, symptom duration, diagnostic imaging, treatment, complications, and clinical and radiological follow-up. RESULTS: Patients were 5 men and 2 women (mean age, 66 years; range, 45-76 years). Symptom duration varied from 2 months to 6 years. Six patients underwent embolization of the AVM as the primary treatment; 1 patient was treated after attempted surgery. Complete obliteration was demonstrated in each patient on completion angiography and was confirmed during follow-up in 6. Three patients had resolution of their preembolization symptoms. Three patients had improvement but not complete resolution of their motor deficits. In 1 patient, the AVM was an incidental finding during an investigation for chronic low-back pain; symptoms were not thought to be related to the AVM, and symptoms were not ameliorated by successful embolization. CONCLUSION: Our early experience with these uncommon lesions suggests that Onyx embolization is a valuable and effective strategy for extradural spinal AVMs and intradural venous drainage.

Background and Purpose Endovascular and surgical options are both available for the treatment of unruptured cerebral aneurysms. Knowledge of the costs for hospitalization of these patients is important to understanding economic impact of these patients on hospitals. Methods Using the National Inpatient Sample, hospitalizations for clipping and coiling of unruptured cerebral aneurysms from 2001 to 2008 were identified by cross-matching ICD-9 codes for diagnosis of unruptured aneurysm with procedure codes for clipping or coiling of cerebral aneurysms, and excluding all patients with diagnosis of subarachnoid hemorrhage and intracerebral hemorrhage. Hospital costs for 2008 were correlated with age, gender, and discharge status, and compared to Medicare payments. Results Costs of both clipping and coiling have increased from 2001 to 2008. The median 2008 hospital costs were US$23 574 (IQR 18233–29941) for clipping and US$25 734 (IQR 17436–35846) for coiling without complication, which were higher than the average Medicare payment of US$12 599. The median hospital costs were US$36 188 (IQR 21831–55308) for clipping and US$40 502 (IQR 24289–50108) for coiling treatments complicated by major morbidity, and US$68 165 (IQR 32972–100211) for clipping and US$56 020 (IQR 00000–00000) for coiling treatments complicated by mortality, which were higher than the average Medicare payments for patients with major complications and comorbidities of US$22 946. In multivariate analysis, female gender was associated with higher costs for coiling (p=0.02), and poor discharge status was associated with higher costs for both clipping (p<0.001) and coiling (p<0.001). Conclusions Hospitalization costs for patients undergoing clipping and coiling of unruptured cerebral aneurysms are substantially higher than Medicare payments.

The introduction of flow diverters for treatment of intracranial aneurysms represents a major paradigm shift in the treatment of these lesions. The theoretical hallmark of flow diverters is the treatment of the diseased segment harboring the aneurysm instead of treating the aneurysm itself. Flow diverters are designed to induce disruption of flow near the aneurysm neck while preserving flow into parent vessel and adjacent branches. After flow diversion, intra-aneurysmal thrombosis occurs, followed by shrinkage of the aneurysmal sac as the thrombus organizes and retracts. Preliminary clinical series document effective treatment of wide-neck and/or large and giant aneurysms with acceptable complication rates. However, several questions remain unanswered related to the incidence and mechanisms of aneurysm rupture after treatment with flow diverters, fate of small perforating vessels, and long-term patency rates.

Background and Purpose— To evaluate the periprocedural outcome after carotid artery stenting with embolic brain protection (EBP+) versus without embolic brain protection (EBP−). Methods— We retrospectively reviewed data from a prospective nonrandomized database of 357 patients who underwent carotid artery stenting in the neuroradiology division of our institution from 1999 to 2009. One hundred five patients underwent angioplasty and stenting without distal protection, whereas 252 were treated with distal protection. Patients were analyzed according to their EBP status (+ or −) for the primary end points of perioperative stroke, death, or myocardial infarction. Results— Unprotected stenting was mostly performed in the early years of this study and this is reflected in significant baseline differences between the two groups. In our earlier experience, carotid artery stenting was used in patients with more significant comorbidities. Diabetes mellitus ( P =0.04), previous coronary artery disease ( P =0.02) and myocardial infarction ( P =0.04), and symptomatic lesion ( P =0.01) were significantly more common in the EBP− cohort. Despite these baseline differences, there were no significant differences in the primary end points (2% in the EBP+ group and 4.8% in the EBP−, P =0.15). The incidence of ipsilateral stroke in the EBP− and in the EBP+ group was 3.8% versus 0.8%, respectively ( P =0.6). There were 2 perioperative deaths (1 in each group) and 4 myocardial infarctions (3 in the EBP+ arm and 1 in the EBP− arm, all non-Q infarcts; P =nonsignificant). Conclusions— In accordance with recent literature, this series cast doubts as to the real effectiveness of distal embolic protection devices in reducing periprocedural complications.