Showing papers by "J Mocco published in 2010"

Size Ratio Correlates With Intracranial Aneurysm Rupture Status. A Prospective Study

Abstract: Background and Purpose— The prediction of intracranial aneurysm (IA) rupture risk has generated significant controversy. The findings of the International Study of Unruptured Intracranial Aneurysms (ISUIA) that small anterior circulation aneurysms (<7 mm) have a 0% risk of subarachnoid hemorrhage in 5 years is difficult to reconcile with other studies that reported a significant portion of ruptured IAs are small. These discrepancies have led to the search for better aneurysm parameters to predict rupture. We previously reported that size ratio (SR), IA size divided by parent vessel diameter, correlated strongly with IA rupture status (ruptured versus unruptured). These data were all collected retrospectively off 3-dimensional angiographic images. Therefore, we performed a blinded prospective collection and evaluation of SR data from 2-dimensional angiographic images for a consecutive series of patients with ruptured and unruptured IAs. Methods— We prospectively enrolled 40 consecutive patients presenting ...

Characterization of Critical Hemodynamics Contributing to Aneurysmal Remodeling at the Basilar Terminus in a Rabbit Model

Abstract: Background and Purpose— Hemodynamic insult by bilateral common carotid artery ligation has been shown to induce aneurysmal remodeling at the basilar terminus in a rabbit model. To characterize critical hemodynamics that initiate this remodeling, we applied a novel hemodynamics–histology comapping technique. Methods— Eight rabbits received bilateral common carotid artery ligation to increase basilar artery flow. Three underwent sham operations. Hemodynamic insult at the basilar terminus was assessed by computational fluid dynamics. Bifurcation tissue was harvested on day 5; histology was comapped with initial postligation hemodynamic fields of wall shear stress (WSS) and WSS gradient. Results— All bifurcations showed internal elastic lamina loss in periapical regions exposed to accelerating flow with high WSS and positive WSS gradient. Internal elastic lamina damage happened 100% of the time at locations where WSS was >122 Pa and WSS gradient was >530 Pa/mm. The degree of destructive remodeling accounting ...

Length of Stay and Total Hospital Charges of Clipping Versus Coiling for Ruptured and Unruptured Adult Cerebral Aneurysms in the Nationwide Inpatient Sample Database 2002 to 2006

Abstract: Background and Purpose—We have previously reported the difference in length of stay and hospital charges for patients with cerebral aneurysms treated with either clipping or coiling at our institution. We now report an analysis of the same comparison at a national level conducted using the Nationwide Inpatient Sample database. Methods—We obtained the Nationwide Inpatient Sample from the Healthcare Cost and Utilization Project, Agency for Healthcare Quality and Research. The Nationwide Inpatient Sample is the largest all-payer inpatient care database in the US and represents ≈20% of all inpatient admissions to US nonfederal hospitals. Hospitalizations for clipping or coiling of ruptured and unruptured cerebral aneurysms from 2002 to 2006 were identified by cross-matching International Classification of Diseases-9 codes for diagnoses of subarachnoid hemorrhage (430) or unruptured cerebral aneurysm (437.3) with procedure codes for clipping (39.51) or coiling (39.79, 39.72, or 39.52) of cerebral aneurysms. Le...

Effect of weekend compared with weekday stroke admission on thrombolytic use, in-hospital mortality, discharge disposition, hospital charges, and length of stay in the Nationwide Inpatient Sample Database, 2002 to 2007.

Abstract: Background and Purpose—A stroke “weekend effect” on mortality has been demonstrated in other countries with a possible slight effect in the United States. We studied patients with stroke in the Nationwide Inpatient Sample database for a weekend effect on thrombolytic use, in-hospital mortality, discharge disposition, hospital charges, and length of stay. Methods—The Nationwide Inpatient Sample 2002 to 2007 was searched for all emergency room admissions for International Classification of Diseases, 9th Revision codes corresponding to ischemic stroke. Generalized estimated equations for generalized linear models were performed, adjusting for gender, age, race, season, median income level, payer, comorbidity score, hospital region, hospital location, teaching status, bed size, and hospital annual stroke case volume to compare weekend versus weekday stroke admission incidence of thrombolytic use, in-hospital mortality, discharge disposition, hospital charges, and length of stay. The same analysis was performe...

Use of a vascular reconstruction device to salvage acute ischemic occlusions refractory to traditional endovascular recanalization methods.

Abstract: Object Acute revascularization has been associated with improved stroke outcomes. The Prolyse in Acute Cerebral Thromboembolism (PROACT II) trial achieved recanalization rates of 66%. The Multi Mechanical Embolus Removal in Cerebral Ischemia (Multi MERCI) trial achieved recanalization in 70% of patients. However, these interventional tools are not always successful. The Enterprise vascular reconstruction device was recently introduced for treatment of cerebral aneurysms previously untreatable with endovascular techniques. The authors evaluated a multicenter experience using this stent as a salvage revascularization tool for acute stroke treatment. Methods Four medical centers participated in a retrospective review of endovascularly treated patients with acute stroke for cases treated with the Enterprise stent after routine interventions had been unsuccessful. Data collected included preprocedure information, intraprocedure findings, and outcomes. Results Twenty patients with acute stroke (mean age 61.6 ± ...

The balloon anchor technique: a novel technique for distal access through a giant aneurysm.

Abstract: A novel technique is reported that helps the operator in achieving reliable access to the distal parent vessel with a microcatheter for stent assisted aneurysm coiling. Distal parent vessel access was obtained by allowing the microwire to follow the local hemodynamics into a giant internal carotid artery aneurysm and around its dome. Various traditional methods were tried before attempting the balloon anchor. In this technique, an over-the-wire balloon was inflated in the distal vessel followed by gentle retraction of the balloon catheter and microwire allowed only a wire bridge across the aneurysm neck, thereby allowing the stent catheter to be brought up in a standard fashion. This technique may facilitate the use of new stent technologies for the treatment of aneurysms that would otherwise be untreatable with endovascular therapies.

Timing of aneurysm surgery: the International Cooperative Study revisited in the era of endovascular coiling

Abstract: Objective The International Cooperative Study on the Timing of Aneurysm Surgery demonstrated that subarachnoid hemorrhage (SAH) patients who underwent surgery on post-hemorrhage days 4–10 had worse outcomes than patients treated on days 0–3 and days 11–14. Based on these findings, it was concluded that patients who present with SAH on days 4–10 should have aneurysm surgery delayed until after day 10. Since the study, coiling has become a treatment option and it is unclear whether these results apply to this new treatment modality. Our institution is a regional referral center for SAH, and patients are transferred at different time points after hemorrhage. We wanted to determine whether patients that arrive on days 4–10 were safe to undergo coiling immediately rather than waiting until after day 10. Methods We reviewed 119 consecutive SAH patients who underwent coiling between January 2006 and June 2008. Factors of age, gender, Hunt–Hess grade, Fisher score, aneurysm size and aneurysm location were included in a regression analysis to determine the effect of day of coiling on clinical outcome at discharge. Results Of 119 study patients, 86% had coiling on post-hemorrhage days 0–3, and 12% on days 4–10. Patients in these cohorts did not differ in any demographic factors. Age and Hunt–Hess grade were the only predictors of mortality (age p=0.0001, Hunt–Hess p=0.0110) and poor outcome, defined as death or discharge to a skilled nursing facility (age p=0.0001, Hunt–Hess p=0.0001). Day of coiling had no effect on mortality (p=0.5731) or poor outcome (p=0.1861). Conclusions Coiling of ruptured aneurysms can be performed safely on patients who arrive on post-hemorrhage days 4–10, and treatment need not be delayed after day 10, as the results of the Timing of Aneurysm Surgery Study initially suggested.

Mapping vascular response to in vivo hemodynamics: application to increased flow at the basilar terminus.

Abstract: Hemodynamic forces play critical roles in vascular pathologies such as atherosclerosis, aneurysms, and stenosis. However, detailed relationships between the specific in vivo hemodynamic microenvironment and vascular responses leading to the triggering or exacerbation of pathological remodeling of the vessel remain elusive. We have developed a hemodynamics-biology co-mapping technique that enables in situ correlation between the in vivo blood flow field and vascular changes secondary to hemodynamic insult. The hemodynamics profile is obtained from computational fluid dynamics simulation within the vascular geometry reconstructed from three-dimensional in vivo images, whereas the vascular response is obtained from histology or immunohistochemistry on harvested vascular tissue. The hemodynamics field is virtually sectioned in the histological slicing planes and digitally co-mapped with the histological images, thereby enabling correlation of the specific local vascular responses with the inciting hemodynamic stresses. We demonstrate application of this technique to rabbit basilar terminus subjected to elevated flow. Morphological changes at the basilar terminus 5 days after the flow increase were co-mapped with the initial wall shear stress and wall shear stress gradient distributions, from which localization of destructive remodeling in a specific hemodynamic zone was noticed. This method paves the way for further investigations to determine the connection between in vivo mechanical stimuli and biological responses, such as initiation of aneurysmal remodeling.

Acute intraprocedural thrombus formation during wingspan intracranial stent placement for intracranial atherosclerotic disease.

Abstract: Background Treatment of intracranial atherosclerotic disease with the Wingspan-Gateway intracranial stent and balloon angioplasty system has been reported in several multicenter registries. To date, the incidence of acute intraprocedural thrombus formation during Wingspan stent placement has not been reported. Objective We reviewed the incidence of acute thrombus formation, treatment, and outcome for patients who underwent Wingspan stent placement by the senior author (B.L.H.) between June 2006 and April 2009. Methods We routinely perform angiograms every 10 minutes for at least 30 minutes after placement of a Wingspan stent to check for acute thrombus formation. Acute thrombus was graded: (1) visible thrombus but not flow limiting, (2) visible and flow-limiting thrombosis, and (3) complete stent occlusion. Recanalization was graded according to Thrombosis In Myocardial Infarction score. Results Forty-one patients underwent Wingspan stent placement for intracranial stenosis. Acute intraprocedural thrombus formation developed in 6 (14.6%) within 20 minutes after stent placement: 3 grade 1, 1 grade 2, and 2 grade 3. All 6 were successfully recanalized with Thrombosis In Myocardial Infarction score 3 after intravenous abciximab with or without intra-arterial tissue plasminogen activator and/or balloon angioplasty. There was no morbidity, and all 6 patients were discharged home at their neurological baseline. Conclusion We recommend serial angiography every 10 minutes for at least 30 minutes after placement of Wingspan stents. Once detected, acute thrombosis can be successfully treated with intravenous abciximab with or without intra-arterial tissue plasminogen activator and/or balloon angioplasty.

Primary intracranial stenting in acute ischemic stroke.

Abstract: Acute intracranial stroke is a major source of morbidity and mortality in the United States. Recent studies have shown improved clinical outcomes for patients who achieve timely arterial recanalization. Multimodal therapies have evolved to meet this end point and include intravenous and/or intra-arterial thrombolysis and mechanical thrombolysis. Modifications to existing balloon-mounted stents commonly used in cardiology have yielded more easily navigable and safer self-expanding intracranial stents that provide rapid arterial recanalization. We review the evolution of acute stroke therapy over the past few decades and the recent results of mechanical thrombolysis, focusing on intracranial stenting in the setting of acute stroke.

Aneurysmal Changes at the Basilar Terminus in the Rabbit Elastase Aneurysm Model

Abstract: We read the interesting report by Dai et al,[1][1] wherein the authors examined histology at the basilar terminus (BT) following right common carotid artery (RCCA) ligation as a part of a procedure to create an elastase aneurysm model in 30 consecutive New Zealand white rabbits at various time