Jean Raymond

Long-Term Angiographic Recurrences After Selective Endovascular Treatment of Aneurysms With Detachable Coils

Background and Purpose— Our aim in this study was to assess the incidence and determining factors of angiographic recurrences after endovascular treatment of aneurysms. Methods— A retrospective analysis of all patients with selective endosaccular coil occlusion of intracranial aneurysms prospectively collected from 1992 to 2002 was performed. There were 501 aneurysms in 466 patients (mean±SD age, 54.20±12.54 years; 74% female). Aneurysms were acutely ruptured (54.1%) or unruptured (45.9%). Mean±SD aneurysm size was 9.67±5.91 mm with a 4.31±1.97-mm neck. The most frequent sites were basilar bifurcation (27.7%) and carotid ophthalmic (18.0%) aneurysms. Recurrences were subjectively divided into minor and major (ideally necessitating re-treatment). The most significant predictors of angiographic recurrence were determined by logistic regression. These results were confirmed by &khgr;2, t tests, or ANOVAs followed, when appropriate, by Tukey’s contrasts. Results— Short-term (≤1 year) follow-up angiograms were available in 353 aneurysms (70.5%) and long-term (>1 year) follow-up angiograms, in 277 (55%), for a total of 383 (76.5%) followed up. Recurrences were found in 33.6% of treated aneurysms that were followed up and that appeared at a mean±SD time of 12.31±11.33 months after treatment. Major recurrences presented in 20.7% and appeared at a mean of 16.49±15.93 months. Three patients (0.8%) bled during a mean clinical follow-up period of 31.32±24.96 months. Variables determined to be significant predictors (P <0.05) of a recurrence included aneurysm size ≥10 mm, treatment during the acute phase of rupture, incomplete initial occlusions, and duration of follow-up. Conclusions— Long-term monitoring of patients treated by endosaccular coiling is mandatory.

Safety and Efficacy of Endovascular Treatment of Acutely Ruptured Aneurysms

OBJECTIVE To study the safety and efficacy of endovascular treatment of acutely ruptured aneurysms with Guglielmi detachable coils. METHODS From August 1992 until December 1995, 75 patients were referred for endovascular treatment of acutely ruptured aneurysms. There were 49 women and 26 men, with a mean age of 55 years. Patients were classified according to the Hunt and Hess grading system. There were 18 Grade I patients (24%), 13 Grade II patients (17%), 30 Grade III patients (40%), 11 Grade IV patients (15%), and 3 Grade V patients (4%). Fifty patients (66%) were treated within 48 hours, and 64 (85%) were treated within 1 week of hemorrhage. The most frequently treated aneurysms were located at the basilar bifurcation (32%), anterior communicating artery (16%), posterior communicating artery (15%), and ophthalmic segment of the carotid artery (11%). Most of the aneurysms were smaller than 15 mm (77%). Fifty-six percent of the aneurysms had small (4 mm) necks, and 44% had wide (> 4 mm) necks. Clinical follow-up was performed at 6 months, and results were classified according to the Glasgow Outcome Scale (GOS). Control angiograms were performed immediately, at 6 months, and yearly thereafter. RESULTS Immediate angiographic results were considered to be satisfactory in 58 patients (77%) (complete obliteration, 40%; residual neck and dog ear, 37%). Technical failures occurred in 5 patients (7%), and 12 patients experienced some residual opacification of their aneurysms (16%). The procedure-related mortality and morbidity rate was 8%. At 6 months, the outcomes were as follows: GOS score of 1, 50 patients (66.7%); GOS score of 2, 4 patients (5.3%); GOS score of 3, 4 patients (5.3%); and GOS score of 5, 17 patients (22.7%). The main causes of death and disability at 6 months were the direct effect of the initial hemorrhage (9%), delayed ischemia (6.7%), subsequent bleeding (4%), intraprocedural rupture (4%), open surgical complications (3%), and unrelated deaths (4%). Six-month angiographic follow-up data were available for 50 patients (67%). The morphological results were considered to be satisfactory in 44 of these 50 patients (88%) (complete occlusion, 46%; residual neck or dog ear, 42%). CONCLUSION Endovascular treatment of acutely ruptured aneurysms was attempted without clinically significant complication in 92% of the patients. The morphological results were unsatisfactory in 23% of the patients. Complete obliteration of the sac, with or without residual neck, is essential to prevent subsequent bleeding, which occurred in 5% of the patients. The overall outcome at 6 months was similar to that of surgical series, despite a selected group of patients with negative prognostic factors.

The Role of Transvenous Embolization in the Treatment of Intracranial Dural Arteriovenous Fistulas

OBJECTIVE To evaluate the role of transvenous embolization in the treatment of intracranial dural arteriovenous fistulas (DAVFs), including its efficacy and safety. METHODS We retrospectively studied the charts of 24 patients (21 women and 3 men) treated for an intracranial DAVF since 1990 in whom a transvenous approach was attempted either alone (16 patients) or in combination with arterial embolization (8 patients). There were 12 cavernous sinus, 9 transverse-sigmoid sinus, 2 inferior petrosal sinus, and 1 intradiploic fistulas. Three fistulas were Type I, 12 were Type IIa, and 9 were Type IIa+b, according to the revised Djindjians classification. Transvenous embolic agents included coils (17 patients), detachable balloons (6 patients), bucrylate (2 patients), and silk sutures (1 patient). RESULTS Anatomic cure was proven in 21 patients (87.5%). Clinical cure was obtained in 23 cases (96%), as follows: 15 patients with a single transvenous approach, 6 with a combined arteriovenous approach, and 2 with an arterial approach after failure of venous access. There was one persistent cavernous fistula despite coil packing of the cavernous sinus. Complications were as follows: five transient and one permanent sixth nerve palsies in cavernous DAVFs, two transient labyrinthic dysfunctions in transverse sinus DAVFs, and one subarachnoid hemorrhage without sequelae. CONCLUSION Transvenous embolization is a useful and safe approach in the management of intracranial DAVFs.

Cold hibernated elastic memory foams for endovascular interventions

Cold hibernated elastic memory (CHEM) polyurethane-based foam is a new shape memory polymeric self-deployable structure. Standard cytotoxicity and mutagenicity tests were conducted on CHEM in vitro, to ensure biocompatibility before studying potential medical applications. In vivo, lateral wall aneurysms were constructed on both carotid arteries of eight dogs. Aneurysms were occluded per-operatively with CHEM blocks. In two dogs, CHEM embolization was compared with gelatin sponge fragment embolization. Internal maxillary arteries (Imax) were also occluded with CHEM using a 6F transcatheter technique. Angiography and pathology were used to study the evolution of aneurysms and Imax at 3 and 12 weeks. Imax embolized with CHEM foam remained occluded at 3 weeks. Most aneurysms embolized with CHEM showed a small residual crescent of opacification at initial angiography, but angiographic scores were significantly better at 3 weeks. Thick neointima formation over the CHEM at the neck of aneurysms was demonstrated at pathology. The foamy nature of CHEM favours the ingrowth of cells involved in neointima formation. New devices for endovascular interventions could be designed using CHEMs unique physical properties.

Medical applications of shape memory polymers.

Shape memory polymers (SMP) are lightweight, have a high strain/shape recovery ability, are easy to process, and required properties can be tailored for variety of applications. Recently a number of medical applications have been considered and investigated, especially for polyurethane-based SMP. SMP materials were found to be biocompatible, non-toxic and non-mutagenic. The glass transition temperature (T(g)) can be tailored for shape restoration/self-deployment of clinical devices when inserted in the human body. Newly developed SMP foams, together with cold hibernated elastic memory (CHEM) processing, further broaden their potential biomedical applications. Polyurethane-based SMP are described here and major advantages are identified over other medical materials. Some SMP applications are already used in a clinical setting, whereas others are still in development. Lately, several important applications are being considered for CHEM foams as self-deployable vascular and coronary devices. One example is the endovascular treatment of aneurysms.

Endovascular Treatment of Intracranial Unruptured Aneurysms: Systematic Review and Meta-Analysis of the Literature on Safety and Efficacy

PURPOSE To report an updated, systematic review of medical literature from January 2003 to July 2008, on endovascular treatment (EVT) of intracranial unruptured aneurysms (UAs) (a) to assess the morbidity and case fatality rate of EVT of UAs, (b) to understand how bias can affect results, and (c) to estimate the efficacy of EVT by using reported digital subtraction angiographic (DSA) results and clinical follow-up events. MATERIALS AND METHODS This article was prepared in accordance with the Meta-Analysis of Observational Studies in Epidemiology and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The literature was searched by using PubMed and the EMBASE and Cochrane Library databases. Eligibility criteria were (a) explicit procedural mortality and morbidity rates; (b) at least 10 patients; (c) saccular, intradural, nondissecting UAs; (d) original study published in English or French between January 2003 and July 2008; and (e) a methodological quality score higher than 6, according to Strengthening the Reporting of Observational Studies in Epidemiology criteria. End points included procedural mortality and morbidity, defined as a modified Rankin scale score of 3-6 at 1 month, and efficacy, estimated by using immediate and follow-up digital subtraction angiographic results, as well as delayed hemorrhagic events. RESULTS Seventy-one studies were included. Procedural unfavorable outcome was found in 4.8% (random-effect weighted average; 189 of 5044) of patients (99% confidence interval [CI]: 3.9%, 6.0%). Immediate angiographic results showed satisfactory occlusion in 86.1% (2660 of 3089) of UAs. Recurrences were shown in 321 (24.4%) of 1316 patients followed up for 0.4-3.2 years. Retreatment was performed in 9.1% (random-effect weighted average; 166 of 1699) of patients (99% CI: 6.2%, 13.1%). The annual risk of bleeding after EVT was 0.2% (random-effect weighted average; nine of 1395) of patients (99% CI: 0.1%, 0.3%), but clinical follow-up was short, limited to the first 6 months for 76.7% (n = 1071) of reported patients. CONCLUSION EVT of UAs can be performed with relative safety. The efficacy of treatment as compared with observation has not been rigorously documented.

Association of endovascular therapy of very small ruptured aneurysms with higher rates of procedure-related rupture

OBJECT Procedure-related rupture during endovascular therapy of intracranial aneurysms is associated with a mortality rate of more than one third. Previously ruptured aneurysms are a known risk factor for procedure-related rupture. The objective of this study was to evaluate whether very small, ruptured aneurysms are associated with more frequent intraprocedural ruptures. METHODS This was a retrospective cohort study in which the investigators examined consecutive ruptured aneurysms treated with coil embolization at a single institution. The study was approved by the institutional review board. Very small aneurysms were defined as < or = 3 mm. Procedure-related rupture was defined as contrast extravasation during treatment. Univariate analysis with the Fisher exact test and the Mann-Whitney U test was performed. RESULTS Between August 1992 and January 2007, 682 aneurysms were selectively treated with coils in 668 patients. Procedure-related rupture occurred in 7 (11.7%) of 60 aneurysms < or = 3 mm, compared with 14 (2.3%) of 622 aneurysms > 3 mm (relative risk 5.2, 95% confidence interval 2.2-12.8; p < 0.001). Among cases with procedure-related rupture, inflation of a compliant balloon was associated with better outcome (Glasgow Outcome Scale Score > or = 4) compared with patients treated without balloon assistance (5 of 5 compared with 7 of 16; p = 0.05). Death resulting from procedure-related rupture occurred in 8 (38%) of 21 patients, and a vegetative state occurred in 1 patient. Clinical outcome was good in the other 12 patients (57%). CONCLUSIONS Endovascular coil embolization of very small (< or = 3 mm) ruptured cerebral aneurysms is 5 times more likely to result in procedure-related rupture compared with larger aneurysms. Balloon inflation for hemostasis may be associated with better outcome in the event of intraprocedural rupture and merits further study.

Safety and occlusion rates of surgical treatment of unruptured intracranial aneurysms: a systematic review and meta-analysis of the literature from 1990 to 2011

Background and purpose Surgical clipping of unruptured intracranial aneurysms (UIAs) has recently been challenged by the emergence of endovascular treatment. We performed an updated systematic review and meta-analysis on the surgical treatment of UIAs, in an attempt to determine the aneurysm occlusion rates and safety of surgery in the modern era. Methods A detailed protocol was developed prior to conducting the review according to the Cochrane Collaboration guidelines. Electronic databases spanning January 1990–April 2011 were searched, complemented by hand searching. Heterogeneity was assessed using I2, and publication bias with funnel plots. Surgical mortality and morbidity were analysed with weighted random effect models. Results 60 studies with 9845 patients harbouring 10 845 aneurysms were included. Mortality occurred in 157 patients (1.7%; 99% CI 0.9% to 3.0%; I2=82%). Unfavourable outcomes, including death, occurred in 692 patients (6.7%; 99% CI 4.9% to 9.0%; I2=85%). Morbidity rates were significantly greater in higher quality studies, and with large or posterior circulation aneurysms. Reported morbidity rates decreased over time. Studies were generally of poor quality; funnel plots showed heterogeneous results and publication bias, and data on aneurysm occlusion rates were scant. Conclusions In studies published between 1990 and 2011, clipping of UIAs was associated with 1.7% mortality and 6.7% overall morbidity. The reputed durability of clipping has not been rigorously documented. Due to the quality of the included studies, the available literature cannot properly guide clinical decisions.

Endovascular Treatment of Intracranial Unruptured Aneurysms: A Systematic Review of the Literature on Safety with Emphasis on Subgroup Analyses

PURPOSE To report subgroup analyses of an updated systematic review on endovascular treatment of intracranial unruptured aneurysms (UAs); to compare types of embolic agents, adjunct techniques, and newer devices; and to identify potential risk factors for poor outcomes. MATERIALS AND METHODS Meta-Analysis of Observational Studies in Epidemiology and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used to prepare this article, and the literature was searched with PubMed and with EMBASE and Cochrane databases. Six eligibility criteria (procedural complications rates; at least 10 patients; saccular, nondissecting UAs; original study published in English or French between January 2003 and July 2011; methodological quality score > 6 [modified Strengthening and Reporting of Observational Studies in Epidemiology criteria]; a study published in a peer-reviewed journal) were used. End points included procedural mortality and unfavorable outcomes (death or modified Rankin Scale, Glasgow Outcome Scale, or World Federation of Neurosurgeons Scale at 1 month scores, all > 2). A fixed-effects model (Mantel-Haenszel) was used for pooled estimates of mortality and unfavorable outcomes; a random-effects model (DerSimonian-Laird) was used in case of heterogeneity. RESULTS Ninety-seven studies with 7172 patients (26 studies published July 2008 through July 2011) were included. Sixty-nine (1.8%) of 7034 patients died (fixed-effect weighted average; 99% confidence interval [CI]: 1.4%, 2.4%; Q value, 55.0; I(2) = 0%). Unfavorable outcomes, including death, occurred in 4.7% (242 of 6941) of patients (99% CI: 3.8, 5.7; Q value, 128.3; I(2) = 26.8%). Patients treated after 2004 had better outcomes (unfavorable outcome, 3.1; 99% CI: 2.4, 4.0) than patients treated during 2001-2003 (unfavorable outcome, 4.7%; 99% CI: 3.6%, 6.1%; P = .01) or in 2000 and before (unfavorable outcome, 5.6%; 99% CI: 4.7%, 6.6%; P < .001). Significantly higher risk was associated with liquid embolic agents (8.1%; 99% CI: 4.7%, 13.7%) versus simple coil placement (4.9%; 99% CI: 3.8%, 6.3%; P = .002). Unfavorable outcomes occurred in 11.5% (99% CI: 4.9%, 24.6%) of patients treated with flow diversion. CONCLUSION Procedure-related poor outcomes occurred (4.7% of patients), risks decreased, and liquid embolic agents and flow diversion were associated with higher risks.

Analysis by Categorizing or Dichotomizing Continuous Variables Is Inadvisable: An Example from the Natural History of Unruptured Aneurysms

SUMMARY: In medical research analyses, continuous variables are often converted into categoric variables by grouping values into ≥2 categories. The simplicity achieved by creating ≥2 artificial groups has a cost: Grouping may create rather than avoid problems. In particular, dichotomization leads to a considerable loss of power and incomplete correction for confounding factors. The use of data-derived “optimal” cut-points can lead to serious bias and should at least be tested on independent observations to assess their validity. Both problems are illustrated by the way the results of a registry on unruptured intracranial aneurysms are commonly used. Extreme caution should restrict the application of such results to clinical decision-making. Categorization of continuous data, especially dichotomization, is unnecessary for statistical analysis. Continuous explanatory variables should be left alone in statistical models.