Evaluating a calcium chloride-elastase combination for creating large aneurysms in the endovascular rabbit elastase model.

PurposeLarge aneurysms have a higher rupture risk, yet no available in vivo animal model consistently produces large aneurysms for testing endovascular therapies. Recent research suggests that adding calcium chloride (CaCl2) to elastase yields larger aneurysms in a surgical rabbit model. We evaluated whether this effect translates to an endovascular approach by comparing aneurysm sizes created using elastase alone versus a CaCl2-elastase combination.MethodsAneurysms were created in the right common carotid artery of New Zealand rabbits. One group received 1 mL porcine elastase; the other received elastase plus 0.055 g CaCl2 (0.5 M). After four weeks, patency was confirmed via digital subtraction angiography. Two blinded co-authors measured the neck, width, and height of the aneurysms. Aneurysm volumes were estimated using AngioCalc.com. Statistical analyses were performed using either the Mann-Whitney U-test or t-test based on data distribution.ResultsTwenty-nine (29) New Zealand rabbits were included in the study: six in the CaCl2 and elastase groups, 23 in the elastase-alone group. All induced aneurysms remained patent at follow-up. Mean neck size was significantly larger in the CaCl2 + elastase group than in the elastase-alone group (4.4 ± 1.1 mm vs 3.5 ± 0.95 mm; respectively, p = 0.02). Differences in width (4.1 ± 0.92 mm vs 3.4 ± 0.36 mm; p = 0.06), height (9.0 ± 1.1 mm vs 9.1 ± 2.1 mm; p = 0.46), and volume (83.5 ± 38.35 mm³ vs 53.0 ± 16.94 mm³; p = 0.11) were not significant between CaCl2 + elastase and elastase-alone, respectively.ConclusionsCaCl2 modestly increased neck size but did not significantly enlarge overall aneurysm dimensions. Further studies are needed to assess its utility in endovascular aneurysm models.