Rabbit Aneurysm Model Research Articles

Hemodynamic Changes Caused by Flow Diverters in Rabbit Aneurysm Models: Comparison of Virtual and Realistic FD Deployments Based on Micro-CT Reconstruction

Adjusting hemodynamics via flow diverter (FD) implantation is emerging as a novel method of treating cerebral aneurysms. However, most previous FD-related hemodynamic studies were based on virtual FD deployment, which may produce different hemodynamic outcomes than realistic (in vivo) FD deployment. We compared hemodynamics between virtual FD and realistic FD deployments in rabbit aneurysm models using computational fluid dynamics (CFD) simulations. FDs were implanted for aneurysms in 14 rabbits. Vascular models based on rabbit-specific angiograms were reconstructed for CFD studies. Real FD configurations were reconstructed based on micro-CT scans after sacrifice, while virtual FD configurations were constructed with SolidWorks software. Hemodynamic parameters before and after FD deployment were analyzed. According to the metal coverage (MC) of implanted FDs calculated based on micro-CT reconstruction, 14 rabbits were divided into two groups (A, MC >35%; B, MC <35%). Normalized mean wall shear stress (WSS), relative residence time (RRT), inflow velocity, and inflow volume in Group A were significantly different (P<0.05) from virtual FD deployment, but pressure was not (P>0.05). The normalized mean WSS in Group A after realistic FD implantation was significantly lower than that of Group B. All parameters in Group B exhibited no significant difference between realistic and virtual FDs. This study confirmed MC-correlated differences in hemodynamic parameters between realistic and virtual FD deployment.

An improved elastase-based method to create a saccular aneurysm rabbit model

Purpose. To find a safe, effective, and simple method to create a rabbit aneurysm model. Methods. Twelve adult New Zealand rabbits were divided into two groups: experimental (n = 9) and control (n = 3). The origin of the right external carotid artery was occluded with a temporary aneurysm clip, after which the right external carotid artery was ligated distally. The resulting stump was infused with elastase (experimental group) or saline (control group) for 20 minutes, and the clip was removed. The animals were studied angiographically and sacrificed 3 weeks after the procedure to harvest the aneurysms for histological analysis. Results. All nine rabbits in the experimental group successfully developed aneurysm after 3 weeks. Aneurysms had an average height of 5.2 ± 1.1 mm and width of 3.5 ± 0.8 mm. Histological analysis showed that the tunica media of the aneurysmal wall was barely identifiable. None of the three rabbits in the control group developed an aneurysm, and instead had achieved closure of the right external carotid artery stump. Conclusions. We have established an effective and a simple elastase-based method to create a rabbit aneurysm model. The procedure is easy to perform and does not require an interventional technique and or ligation of the internal carotid artery, which would otherwise reduce the blood supply to the brain.

Hemodynamic Changes by Flow Diverters in Rabbit Aneurysm Models

The effect of flow diverter (FD) on hemodynamic changes observed in aneurysms is inevitably affected by the actual structural configuration of deployed FD. We studied the resultant hemodynamic changes after implantation of FDs using computational fluid dynamic simulations based on micro-computed tomography reconstructions in rabbit aneurysm model. The FDs by micro-computed tomography images and vascular model based on rabbit-specific angiograms in 14 rabbits were reconstructed for computational fluid dynamic studies, and rabbit-specific inlet flow waveforms were used as boundary conditions. The occluded group (n=10) and unoccluded group (n=4) were divided according to the follow-up angiography. Hemodynamic parameters were separately evaluated for significance with respect to FD implantation and healing. The normalized mean wall shear stress of the aneurysm sac and inflow volume were significantly reduced after FD deployment, and the relative residence time was significantly increased after treatment, without significant differences in mean pressure of aneurysm sac. When compared with the unoccluded group, the average relative residence time increment and percentage of inflow volume reduction in occluded group were higher. Additionally, the inlet of stream after FD deployment in the occluded group was more prevalent near the central region of the neck, whereas in the unoccluded group, it was more likely to occur near the proximal part of the neck. This study provided the real structural configurations of fully deployed FDs in vivo. We demonstrated the decrease of wall shear stress, inflow volume, increase of relative residence time, and change of inflow stream induced by FD implantation. The higher relative residence time increment, percentage of inflow volume reduction, and location of stream inlet near the central part of the neck may be closely related to healing.

Measurement of quantifiable parameters by time-density curves in the elastase-induced aneurysm model: first results in the comparison of a flow diverter and a conventional aneurysm stent

Quantifiable parameters to evaluate the effectiveness of flow diverters (FDs) are desirable. We measured time-density curves (TDCs) and calculated quantifiable parameters in the rabbit elastase-induced aneurysm model after stent (Neuroform [NF]) and FD (Pipeline embolisation device [PED]) treatment. Sixteen rabbit elastase-induced aneurysms were treated with FD (n = 9) or NF (n = 5). Angiography was performed before and after treatment and TDCs were created. The time to peak (TTP), the full width at half maximum (FWHM) and the average slope of the curve which represent the inflow (IF) and outflow (OF) were calculated. Mean values before treatment were TTP = 0.8 s, FWHM = 1.2 s, IF = 153.5 and OF = -54.9. After PED treatment, the TTP of 1.8 s and FWHM of 47.8 s were extended. The IF was 31.2 and the OF was -11.5 and therefore delayed. The values after NF treatment (TTP = 1.1 s, FWHM = 1.8 s, IF = 152.9, OF = -33.2) changed only slightly. It was feasible to create TDCs in the rabbit aneurysm model. Parameters describing the haemodynamic effect of PED and NF were calculated and were different according to the type of device used. These parameters could possibly serve as predictive markers for aneurysm occlusion.

Elastase-Induced Rabbit Aneurysms Model Complicated by Thoracic Aortic Aneurysms: Fig 1.

Published reports have described the elastase-induced aneurysm model in rabbits as easy and reproducible and possessing geometric, pathologic, and hemodynamic features that are similar to those of human cerebral aneurysms.[1][1] We used a simple surgical technique to produce the elastase-induced

Can aspect ratio be used to categorize intra-aneurysmal hemodynamics?—A study of elastase induced aneurysms in rabbit

Clinical studies suggest that aneurysm aspect ratio (AR) is an important indicator of rupture likelihood. The importance of AR is hypothesized to arise from its influence on intra-aneurysmal hemodynamics. It has been conjectured that slower flow in high AR sacs leads to a cascade of biological activities that weaken the aneurysm wall ( Ujiie et al.,1999). However, the connection between AR, hemodynamics and wall weakening has never been proven. Animal models of saccular aneurysms provide a venue for evaluating this conjecture. The focus of this work was to evaluate whether a commonly used elastase induced aneurysm model in rabbits is suitable for a study of this kind from a hemodynamic perspective. In particular, to assess whether hemodynamic factors in low and high AR sacs are statistically different. To achieve this objective, saccular aneurysms were created in 51 rabbits and pulsatile computational fluid dynamics (CFD) studies were performed using rabbit specific inflows. Distinct hemodynamics were found in the low AR (AR<1.8, n=25), and high AR (AR>2.2, n=18) models. A single, stable recirculation zone was present in all low AR aneurysms, whereas a second, transient recirculation zone was also found in the superior aspect of the aneurysm dome for all high AR cases. Aneurysms with AR between 1.8 and 2.2 displayed transitional flow patterns. Differences in values and distributions of hemodynamic parameters were found between low and high AR cases including time averaged wall shear stress, oscillatory shear index, relative residence time and non-dimensional inflow rate. This work lays the foundation for future studies of the dependence of growth and remodeling on AR in the rabbit model and provides a motivation for further studies of the coupling between AR and hemodynamics in human aneurysms.

Magnetic Microparticles for Endovascular Aneurysm Treatment: In Vitro and In Vivo Experimental Results

Endovascular treatment of intracranial aneurysms employing endosaccular coiling can be associated with aneurysm perforation, coil herniation or incomplete obliteration fueling the interest to investigate novel endovascular techniques. We aimed to test a novel embolization material in experimental aneurysms in vitro and in vivo whereby intra-arterially administered magnetic microparticles (MMPs) are navigated into the lumen of vascular aneurysms with assistance from an external magnetic field. MMPs are core-shell particles suspended in saline that have a shell made of a polymeric material and a core made of magnetite (Fe3O4). They have a diameter of 1.4 μm. During MMP administration via a microcatheter, a magnetic field was applied externally to direct the particles with the use of a solid-state neodymium magnet. Experiments were performed in a perfused silicone vessel and aneurysm model to evaluate application techniques and fluid dynamics and in the elastase aneurysm model in rabbits to evaluate in vivo compatibility, including multiorgan histological examinations and long-term stability of aneurysm embolization. It was possible to steer and hold the MMPs within the aneurismal cavity where they occluded the lumen progressively. After removal of the external magnetic field, the results remained stable in vivo for the remainder of the observational period (30 minutes); after a 12-week observational period, recanalization of the aneurysm occurred. MMPs can be magnetically directed into aneurysms, allowing short-term obliteration. Although the method has yet to show reliable long-term stability, these experiments provide proof of concept, encouraging further investigation of intravascular magnetic compounds.

Hemodynamics and Anatomy of Elastase-Induced Rabbit Aneurysm Models: Similarity to Human Cerebral Aneurysms?

Animal models provide a mechanism for fundamental studies of the coupling between hemodynamics and pathophysiology in diseases such as saccular aneurysms. In this work, we evaluated the capability of an elastase-induced saccular aneurysm model in rabbits to reproduce the anatomic and hemodynamic features typical for human intracranial aneurysms. Saccular aneurysms were created in 51 rabbits at the origin of the RCCA. Twelve weeks' postcreation, the lumen geometry of the aneurysm and surrounding vasculature was acquired by using 3DRA. Geometric features of these models were measured. Pulsatile 3D CFD studies were performed with rabbit-specific inlet profiles. Geometric features, including aneurysm height, width, neck diameter, aspect ratio, and NSI of all 51 rabbit aneurysm models fell within the range reported for human IAs. The distribution and range in values of pressure, WSS, and OSI were also typical for human IAs. A single recirculation region was observed in 33 (65%) of 51 cases, whereas a second transient recirculation zone was observed in 18 (35%) cases. Both of these flow types are commonly observed in human IAs. Most hemodynamic and geometric features in a commonly used elastase-induced rabbit saccular aneurysm model are qualitatively and quantitatively similar to those seen in large numbers of human cerebral aneurysms.

Preliminary Results of the Luna Aneurysm Embolization System in a Rabbit Model: A New Intrasaccular Aneurysm Occlusion Device

Recent advances in endovascular devices have been aimed at providing high density, mesh-like metallic materials across the aneurysm neck, in place of coil technology. Therefore our aim was to report the in vivo preclinical performance of a self-expanding intrasaccular embolization device. Elastase-induced aneurysms were created in 12 rabbits. Each aneurysm was embolized with a Luna AES. DSA was performed preimplantation; 5, 10, and 30 minutes postimplantation; and at 1 month in 12 rabbits and at 3 months in 8 rabbits. Early postimplantation intra-aneurysmal flow was graded as unchanged, moderately diminished, or completely absent. One- and 3-month DSAs were graded by using a 3-point scale (complete, near-complete, or incomplete occlusion). Aneurysms were harvested for gross and microscopic histologic evaluation at 1 month (n = 4) and at 3 months (n = 8). Tissues within the aneurysm dome and across the aneurysm neck were assessed by using HE staining. Ten (83%) of 12 aneurysms demonstrated complete cessation of flow within 30 minutes of device implantation. At 1-month follow-up, 10 (83%) of 12 aneurysms were completely occluded. At 3 months, 7 of 8 (88%) aneurysms remained completely occluded. One-month gross examination in 4 rabbits demonstrated that membranous tissue completely covered the device in 3 subjects (75%). Microscopic examination showed that 3 aneurysms had loose connective tissue filling the aneurysm cavity. Three-month gross and microscopic examinations demonstrated membranous tissue completely covering the device, loose connective tissue filling the aneurysm cavity, and neointima formation crossing the aneurysm neck in 8 of 8 (100.0%) subjects. The Luna AES achieved high rates of complete angiographic occlusion and showed promising histologic findings in the rabbit aneurysm model.

A Modified Technique Improved Histology Similarity to Human Intracranial Aneurysm in Rabbit Aneurysm Model

Persistent undigested elastic membranes and collagen in the tunic media of rabbit elastase-induced aneurysm models lowered their histology similarity to human intracranial aneurysm. Our purpose was to make good the deficiency. Ten New Zealand white rabbits were divided into three groups: six rabbit in two groups for evaluating the difference in various treatments, and four rabbits for long-term observation. We inflated and occluded the right common carotid artery (CCA) by an endovascular technique. The first group of three rabbits was only given 200u elastase in the proximal segment of right CCA; the second group was given 100u elastase and 1.5mg collagenase, then the right CCA was ligated. The first and second groups were studied by magnetic resonance angiography (MRA), sacrificed at three weeks after aneurysm creation, their histology results were obtained and compared with human aneurysm. The third group underwent the same procedure as the second group only for three months of observation with enhanced MRA. Saccular aneurysms formed in all rabbits. Degeneration of the extracellular matrix and atrophy of smooth muscular cells in tunic media were more apparent in the second group. The third group remained stable for more three months. Two modifications included inflating the right CCA with a balloon and adding collagenase incubation can promote an aneurysm model more histologically similar to human aneurysm. In addition the improved aneurysm model remains stability for a long time.

A modified method for elastase -induced aneurysm model in rabbits

Objective To create an animal model to simulate human aneurysms, we modified the elastase - induced aneurysm model by application of a simple surgical technique in rabbits. Methods 33New Zealand white rabbits were divided into three groups: In group 1 ( n = 23 ), a temporary arcuated aneurysm clip was placed at the origin of the right common carotid artery and part of right subclavian artery,and the pancreatic elastase induced aneurysm procedure was undertaken;In group 2 ( n = 5 ), elastase was replaced by saline;And in group 3 ( n = 5 ) , the temporary arcuated aneurysm clip was located 3 mm above the location of the clip in group 1. Intravenous digital subtraction angiography was performed at 3 weeks, 8weeks, 4 months, and 6 months after the procedures, and two animals from group 1, and one each from groups 2 and 3, were euthanized for pathology after angiography. In group 1, aneurysm sizes were compared over time by analysis of variance. Results At every time point, saccular aneurysms were displayed in animals of group 1, but retrograde residuals were displayed in all remaining animals of the other 2 groups.Pathologic analysis showed that aneurysms had a thin wall and absence of elastin in group 1. There was no aneurysm and retrograde thrombosis in group 2. Aneurysms with thrombosis at 3 weeks were absorbed after 2months in group 3. In group 1, the mean aneurysm dimension and diameter of parent vessel were not significantly changed over time ( P ＞ 0. 05 ). Conclusions Elastase and location of the temporary arcuated aneurysm clip are important to the success of this aneurysm model. Key words: Aneurysm; Models, Animal; Pancreatic elastase; Rabbits

Sensitivity of CFD Based Hemodynamic Results in Rabbit Aneurysm Models to Idealizations in Surrounding Vasculature

Computational fluid dynamics (CFD) studies provide a valuable tool for evaluating the role of hemodynamics in vascular diseases such as cerebral aneurysms and atherosclerosis. However, such models necessarily only include isolated segments of the vasculature. In this work, we evaluate the influence of geometric approximations in vascular anatomy on hemodynamics in elastase induced saccular aneurysms in rabbits. One representative high aspect ratio (AR-height/neck width) aneurysm and one low AR aneurysm were created at the origin of the right common carotid artery in two New Zealand white rabbits. Three-dimensional (3D) reconstructions of the aneurysm and surrounding arteries were created using 3D rotational angiographic data. Five models with varying extents of neighboring vasculature were created for both the high and low AR cases. A reference model included the aneurysm sac, left common carotid artery (LCCA), aortic arch, and downstream trifurcation/quadrification. Three-dimensional, pulsatile CFD studies were performed and streamlines, wall shear stress (WSS), oscillatory shear index, and cross sectional velocity were compared between the models. The influence of the vascular domain on intra-aneurysmal hemodynamics varied between the low and high AR cases. For the high AR case, even a simple model including only the aneurysm, a small section of neighboring vasculature, and simple extensions captured the main features of the steamline and WSS distribution predicted by the reference model. However, the WSS distribution in the low AR case was more strongly influenced by the extent of vasculature. In particular, it was necessary to include the downstream quadrification and upstream LCCA to obtain good predictions of WSS. The findings in this work demonstrate the accuracy of CFD results can be compromised if insufficient neighboring vessels are included in studies of hemodynamics in elastase induced rabbit aneurysms. Consideration of aspect ratio, hemodynamic parameters of interest, and acceptable magnitude of error when selecting the vascular domain will increase reliability of the results while decreasing computational time.

Five-Year Follow-Up in Elastase-Induced Aneurysms in Rabbits

There is no report regarding patency of elastase-induced aneurysms for more than a 2-year period. Our aim was to report aneurysm patency rates up to 5 years in the elastase-induced aneurysm model in rabbits. Twenty-five elastase-induced aneurysms were created in New Zealand white rabbits and followed for up to 5 years. Thirteen (52%) rabbits died during follow-up for reasons unrelated to the aneurysms. DSA was performed at 1 month and at 2 and 5 years in the 12 surviving subjects. Aneurysm patency and dimensions, including neck diameter and aneurysm width and height, were evaluated at each time point in relation to external sizing devices. Differences of aneurysm sizes (neck width and aneurysm width and height) among time points were compared by using the Student t test. Eleven (92%) of the 12 aneurysms in the subjects that survived for 5 years remained fully patent throughout follow-up. A single narrow-neck aneurysm showed partial thrombosis at the 2- and 5-year time points. Experimental elastase-induced aneurysms in rabbits demonstrate high rates of patency up to 5 years following creation. When planning for very long-term studies, investigators should plan for relatively high rates of mortality unrelated to aneurysm pathology.

In Vivo Experimental Intracranial Aneurysm Models: A Systematic Review

Animal models are necessary to develop and test innovations in aneurysm therapy before clinical introduction. This review aims at identifying the most likely candidates for standardizing preclinical testing of aneurysm devices. We systematically searched electronic databases for publications on animal aneurysm models from 1961-2008 to assess the methodologic quality of the studies and collect data on the patency and angiographic and pathologic outcomes of treatments. There has been a steady increase in the annual number of publications with time. Species that were most frequently used were dogs, rabbits, and rodents, followed by swine. Most publications are single-laboratory studies with variables and poorly validated outcome measures, a small number of subjects, and limited standardization of techniques. The most appropriate models to test for recurrences after endovascular occlusion were the surgical bifurcation model in dogs, and the elastase-induced aneurysm model in rabbits. A standardized multicenter study is needed to improve the preclinical evaluation of endovascular devices in aneurysm therapy.

005 Hemi neurovascular embolization cover device(NFocus Neuromedical) for the treatment of aneurysms in the rabbit model

Purpose: This study was conducted in order to evaluate the angiographic and histopathologic outcomes of the Hemi neurovascular embolization cover (NEC) in the rabbit aneurysm model. Primary endpoints were patency...

Neurological deficits associated with the elastase-induced aneurysm model in rabbits

Objective: Although the rabbit elastase-induced aneurysm model is currently used widely for endovascular research and device testing, procedural causes leading to animal morbidity and mortality have not yet been clearly described. We conducted a retrospective study to analyse factors contributing to neurological deficits in rabbits that underwent the elastase-induced aneurysm creation procedure at our research center from 2002 to 2005 in order to improve the technique and reduce procedure-related morbidity and mortality.Methods: A total sample of 38 animals that underwent the procedure under the same conditions was analysed in two groups: animals that presented neurological deficits (ND, n=15) and animals that were neurological deficit free (NDF, n=23). Data were collected by reviewing the animal records and radiographic images from the procedures. Statistical analyses using the Mann–Whitney test, unpaired t-test with Welch correction and Fisher's exact tests were performed to compare the two groups based on variables associated with endothelial injury and activation of the coagulation cascade.Results: The variables of animal weight (signifying state of health of the animal), total procedure time, total balloon occlusion time and clot formation were found to be significantly and/or very significantly correlated to ND presentation.Discussion: Successful creation of the rabbit elastase-induced aneurysm model depends on careful control over several technical details. Important variables governing outcome have been identified here. A specific, improved endovascular arrangement that facilitates maneuvering of the devices and reduces the risk of air emboli is presented.

Gene Expression Profiling of Experimental Saccular Aneurysms Using Deoxyribonucleic Acid Microarrays: Fig 1.

The molecular characteristics of the pathophysiology of saccular aneurysms remain poorly understood. The purpose of the current study was to investigate the expression of various groups of genes at different stages of aneurysm age in elastase-induced saccular aneurysms in rabbits through the use of deoxyribonucleic acid (DNA) microarrays. A microarray consisting of genes related to cell adhesion, apoptosis, cell signaling, growth, inflammation, vascular remodeling, and oxidative stress was constructed by using rabbit nucleotide sequences. Elastase-induced saccular aneurysms were created at the origin of the right common carotid artery (CCA) in 12 rabbits. Two weeks (n=6) and 12 weeks (n=6) after aneurysm creation, ribonucleic acid (RNA) was isolated from the aneurysm and the control unoperated left CCA and was used for microarray experiments. Real-time polymerase chain reaction (RT-PCR) was performed for validation of microarray results. Of 209 genes, 157 (75%) at 2 weeks and 88 (42%) at 12 weeks demonstrated statistically significant differential expression between aneurysm tissue and the control left CCA tissue (P < .05). Multiple genes implicated in vessel wall remodeling were found to be elevated at 2 weeks and at 12 weeks. Expression of cell adhesion molecules and antioxidant enzymes was down-regulated at 2 weeks but was not significantly different from that of controls at 12 weeks. Most transcription factors, inflammatory genes, and structural genes showed underexpression at both time points. The expression profiles of selected genes were confirmed by RT-PCR. Multiple genes in diverse pathways have been differentially expressed in the rabbit aneurysm model.

A novel arterial pouch model of saccular aneurysm by concomitant elastase and collagenase digestion

An ideal aneurysm model of cerebral aneurysm is of great importance for studying the pathogenesis of the lesion and testing new techniques for diagnosis and treatment. Several models have been created in rabbits and are now widely used in experimental studies; however, every model has certain intrinsic limitations. Here we report the development of a novel saccular aneurysm model in rabbits using an arterial pouch that is subject to in vitro pre-digestion with combined elastase and collagenase. A segment of right common carotid artery (CCA) was dissected out and treated with elastase (60 U/ml, 20 min) followed by type I collagenase (1 mg/ml, 15 min) in vitro. The graft was anastomosed to an arterial arch built with the left CCA and the remaining right CCA, while the other end of the graft was ligated. The dimension and tissue structure of the pouch were analysed immediately, 2 or 8 weeks after operation. Ten terminal aneurysms were produced. The gross morphology of the aneurysm resembles the human cerebral terminal aneurysms. We have observed the following pathological changes: (1) growth of the aneurysm (mean diameter increased from (2.0+/-0.1) to (3.2+/-0.3) mm at 2 weeks, P<0.001, n=7-10); (2) thinning of the aneurysmal wall (the mean wall thickness decreased to 44% at 2 weeks), which was accompanied by significant losses of elastic fibres, collagen and the cellular component; and (3) spontaneous rupture (3 out of 9, one aneurysm ruptured 24 h after operation with the other two at 2 and 4 weeks respectively). This rabbit arterial pouch model mimics human cerebral aneurysms in relation to morphology and histology. In particular, this model exhibited an increased tendency of spontaneous rupture.

Endovascular Treatment of Experimental Aneurysms by Use of Fibroblast-Coated Platinum Coils

The purpose of this study was to determine whether implanting exogenous fibroblasts on platinum coils could enhance intra-aneurysmal fibrosis. Hypotheses included: (1) fibroblast-coated (FBC) platinum coils can improve angiographic results after embolization; and (2) FBC platinum coils can accelerate histological healing of embolized aneurysms. Experimental aneurysms in rabbits were embolized with control platinum coils (n=18) or FBC coils (n=18). Subjects were euthanized at 14 days, 1 month, 3 months and 6 months after implantation. Digital subtraction angiography was used to evaluate stability after embolization. Histological samples were examined with a grading system (range, 0 to 12) based on neck and dome healing. Histology total scores and fibrosis ratio at 14 days were significantly greater in the FBC coil group compared with controls (6.6+/-1.9 versus 2.5+/-1.1, 1.2+/-0.6% versus 0.2+/-0.3%, respectively; P=0.0090). Cavities embolized with FBC coils showed cellular proliferation and thrombus organization, with an endothelialized membrane bridging the neck. There were no differences between groups in the later timepoints. The FBC coil group showed radiographic stability in 11 (61%) cases, coil compaction in 2 (11%) cases, and progressive occlusion in 5 (28%) cases. No progressive occlusion was seen in controls; 3 (17%) of 18 control cases exhibited coil compaction (P=0.0546). FBC coils can accelerate early histological healing compared with control coils in the rabbit aneurysm model.

Coil Embolization Training Using a Rabbit Saccular Aneurysm Model

We developed a rabbit saccular aneurysm model for coil embolization training. Elastaseinduced aneurysms were created successfully in about 80% of the rabbits. The aneurysms were usually broad in the neck and lengthy. At the 28(th) postoperative day, the aneurysms were about 1.5 times larger in both width and height than they had been at the 14(th) day. All aneurysms were successfully embolized with 18-sized electrically detachable (ED) platinum coils. After embolization, almost all aneurysms had a neck remnant. In conclusion, this model is useful not only for learning the technique of coil embolization but also for testing new embolic materials. The rabbit aneurysm model proved to be an efficacious training modality for endovascular coil embolization.