Naim Khoury

Early CT changes in patients admitted for thrombectomy Intrarater and interrater agreement

Objective: To systematically review the literature and assess agreement on the Alberta Stroke Program Early CT Score (ASPECTS) among clinicians involved in the management of thrombectomy candidates. Methods: Studies assessing agreement using ASPECTS published from 2000 to 2015 were reviewed. Fifteen raters reviewed and scored the anonymized CT scans of 30 patients recruited in a local thrombectomy trial during 2 independent sessions, in order to study intrarater and interrater agreement. Agreement was measured using intraclass correlation coefficients (ICCs) and Fleiss kappa statistics for ASPECTS and dichotomized ASPECTS at various cutoff values. Results: The review yielded 30 articles reporting 40 measures of agreement. Populations, methods, analyses, and results were heterogeneous (slight to excellent agreement), precluding a meta-analysis. When analyzed as a categorical variable, intrarater agreement was slight to moderate (κ = 0.042–0.469); it reached a substantial level (κ > 0.6) in 11/15 raters when the score was dichotomized (0–5 vs 6–10). The interrater ICCs varied between 0.672 and 0.811, but agreement was slight to moderate (κ = 0.129–0.315). Even in the best of cases, when ASPECTS was dichotomized as 0–5 vs 6–10, interrater agreement did not reach a substantial level (κ = 0.561), which translates into at least 5 of 15 raters not giving the same dichotomized verdict in 15% of patients. Conclusions: In patients considered for thrombectomy, there may be insufficient agreement between clinicians for ASPECTS to be reliably used as a criterion for treatment decisions.

Endovascular interventions for acute stroke: past practice and current research

The way clinical care and research are currently conceived is entangled in multiple problems. While the problems are universal, nowhere were they more painfully experienced than in the acute care of patients with severe stroke. While we are celebrating that we now possess evidence that patients can benefit from endovascular interventions, we should not miss the opportunity to review the difficult path that led to this point and reflect on how it could be improved. A narrative review of the past and current status of care and research in endovascular treatment of acute stroke may serve to expose the problems and potential solutions. For more than 25 years, rescue endovascular interventions were offered to selected patients using a vast array of drugs and devices not designed for that purpose with little success, at least in the early years.1 Occasionally, a Lazarus experience (spectacular recovery associated with recanalization) would fuel enough enthusiasm to go on for another long run of failures. We have always been aware that the occasional miracle could not justify a full-scale campaign for the massive resources required to staff centers with expert personnel, streamlined patient transportation, not to mention the generous budget needed for such high-technology care. Clinical research thus focused on intravenous (IV) therapy, a simpler approach which can be delivered locally.2 Following the positive National Institute of Neurological Disorders and Stroke (NINDS) study, subsequent research endeavors were largely devoted to neuroprotective agents promoted by the pharmaceutical industry. Meanwhile, increasingly effective endovascular tools became available, but regulatory agencies never required proof of clinical benefit (angiographic demonstration that vessels can be recanalized would typically suffice) to authorize the sale of ever more expensive devices. Intra-arterial (IA) therapy thus did not have the financial impetus to rigorously assess patient outcomes. Until recently, in the presence of large …

Cervical Internal Carotid Occlusion versus Pseudo-occlusion at CT Angiography in the Context of Acute Stroke: An Accuracy, Interobserver, and Intraobserver Agreement Study

Purpose To evaluate the diagnostic accuracy and reliability of computed tomographic (CT) angiography to distinguish true cervical internal carotid artery (ICA) occlusion from pseudo-occlusion (defined as an isolated intracranial thrombus that impedes ascending blood flow) in the context of acute stroke. Materials and Methods This was a retrospective study of patients who underwent thrombectomy with preprocedural CT angiography that helps to demonstrate a lack of attenuation in the cervical ICA on the symptomatic side (24 men and 13 women; mean age, 63 years; age range, 30-86 years). Seven readers, including five neuroradiologists and two interventional neuroradiology fellows, independently reviewed the CT angiography images to assess whether there was true cervical ICA occlusion. Their results were compared with digital subtraction angiography (DSA) as the reference standard. Sensitivity and specificity for detecting true occlusion as well as accuracy and diagnostic odds ratio were calculated, with inter- and intraobserver κ statistics. Results Cervical ICA pseudo-occlusion occurred in 12 of 37 patients (32.4%) with nonattenuation of the cervical ICA on the symptomatic side. Interobserver agreement coefficients did not reach the substantial value of 0.61 for either pairs or groups of readers. The cohorts average sensitivity and specificity was 68% (95% confidence interval [CI]: 59%, 76%) and 75% (95% CI: 71%, 80%), respectively, with a diagnostic odds ratio of 8 (95% CI: 3, 18) and only fair interobserver agreement (κ = 0.32; 95% CI: 0.16, 0.47). Conclusion In the context of acute ischemic stroke with ipsilateral ICA nonattenuation at single-phase CT angiography, even specialized radiologists may not reliably distinguish true cervical occlusion from pseudo-occlusion.

Embolization with larger-caliber coils can increase packing density: Evidence from the pilot phase of a randomized trial.

Background and purpose Endovascular coil embolization of cerebral aneurysms is associated with suboptimal angiographic results in up to 20–30% of patients. Coil packing density has been used as an index of the success of the initial procedure. The trial sought to study the effects of using 15-caliber coils, as compared with 10-caliber coils, on packing density. Methods Does Embolization with Larger coils lead to better Treatment of Aneurysms (DELTA) is an investigator-initiated multicenter prospective, randomized, controlled clinical trial. Patients are randomized 1:1 to embolization with either 10-caliber coils exclusively (control group) or the highest safely achievable proportion of 15-caliber coils and 10-caliber coils if necessary (intervention group) in 4–12-mm aneurysms. The endpoint of the pilot phase of the trial was the capacity to increase packing density of the initial procedure, calculated using a mathematical transformation of the dimensions entered into the case report forms. Secondary outcomes included the total number of coils used per aneurysm, total fluoroscopy time, initial angiographic outcomes and any adverse or undesirable event. Results Seventy patients were recruited between June 2014 and November 2015. Compared with 10-caliber coils, the 15-caliber coil group had a higher median packing density (44% vs 24%, p = 0.017). Results of other outcome measures were similar for the two groups. Conclusion Coiling of small and medium aneurysms randomized to 15-caliber coils achieved higher packing densities compared with coiling using 10-caliber coils.

A randomized pragmatic care trial on endovascular acute stroke interventions (EASI): criticisms, responses, and ethics of integrating research and clinical care

BackgroundThe Endovascular Acute Stroke Intervention (EASI) trial was conceived as a pragmatic care trial, designed to integrate trial methods with clinical practice. Reporting the EASI experience was met with objections and criticisms during peer review concerning both scientific and ethical issues. Our goal is to discuss these criticisms in order to promote the pragmatic approach of care trials in outcome-based medical care.MethodsThe comments and criticisms of 11 reviewers from 5 journals were collected and analyzed. The EASI protocol was also compared to the protocols of seven thrombectomy trials using the pragmatic-explanatory continuum indicator summary (PRECIS).ResultsMain criticisms of EASI concerned selection criteria that were judged to be too vague and too inclusive, brain and vascular imaging methods that were not sufficiently prescribed by protocol, lack of blinding of outcome assessment, and lack of power. EASI was at the pragmatic end of the spectrum of thrombectomy trials.ConclusionThe pragmatic care trial methodology is not currently well-established. More work needs to be done to integrate scientific methods and ethical care in the best medical interest of current patients.

Unexpected complications with head and neck hydrogel microsphere particle embolization: A case series and a technical note

Endovascular particle embolization is a common procedure with a relatively safe profile. We report here four cases in which cranial nerves, skin and mucosal ischemic complications occurred with the use of hydrogel microspheres (250–500 µm in size). Given the compressibility and higher penetration potential of microsphere particles compared with polyvinyl alcohol particles of similar size, we suggest oversizing hydrogel microsphere particles for head and neck embolizations.

Endovascular treatment of aneurysms and platinum coil caliber: Study protocol of a randomized, controlled trial.

Background Endovascular coil embolization of cerebral aneurysms is an effective treatment for the prevention of aneurysm rebleeding after subarachnoid hemorrhage. It is also often used in unruptured aneurysms, but it is associated with aneurysm remnants and recurrences in up to 20%–33% of patients. We hypothesized that better aneurysm occlusion rates can be achieved with coils of larger caliber. Methods The Does Embolization with Larger coils lead to better Treatment of Aneurysms (DELTA) trial is an investigator-initiated, multicenter, prospective, randomized, controlled clinical trial. To test the hypothesis that 15-caliber coiling systems are superior to 10-caliber coils, 564 patients with aneurysms measuring 4–12 mm will be randomized 1:1 to embolization with either 10-caliber coils exclusively (control group) or the highest safely achievable proportion of 15-caliber coils (intervention group). The primary efficacy endpoint of the trial is the occurrence of a major recurrence or a residual aneurysm at one year. A pilot phase of 165 patients will be conducted to verify feasibility of the coiling strategy, compliance to treatment allocation, safety of a 15-caliber platinum coil embolization strategy, recruitment rates, and the capacity to improve packing density. Discussion The DELTA trial will test the hypothesis that the use of coils of larger caliber can improve angiographic results of endovascular coiling.