Abstract Number ‐ 60: Influence of Primary Wind Diameter and Length on Coil Volume: Comparing Stryker and CEREPAK coils

Abstract

Introduction Coiling procedures for intracranial aneurysms (IAs) performed in the US have steadily increaseda, and volumetric efficiency may become an important consideration for hospitals. Coil volume depends on length and primary wind diameter (PWD), and volumetric efficiency can be achieved by either inserting more coils or using coils with larger volumetric filling. This scenario analysis evaluates the influence of PWD and length on total coil volume by comparing four similar Stryker and CEREPAK coils. Methods In this analysis, we test the influence of PWD (D2) and length (L) on the Coil Volume Formula: [Π(D2/2)2(L)]c. In two hypothetical scenarios, relative percent difference in total coil volume was calculated and compared between four Stryker Target 360 coils and four similar CEREPAK coils that were matched based on closest PWD and L. In scenario I, L remained constant and D2 varied. In scenario II, D2 and L were inversely varied. In both scenarios, coil volume achieved by CEREPAK and Stryker coils was calculated and descriptively compared. Results Scenario I: (a) Stryker Target XL 360 10mm x 40cm (D2 = 0.014”, length = 40cm) with volume of 39.726mm3 was matched to the CEREPAK Heliform XL 10mm x 40cm (D2 = 0.015”, length = 40cm) with 15% greater volume of 45.604mm3. (b)Stryker Target 360 3mm x 6cm (D2 = 0.010”, length = 6cm) with volume 3.040mm3 was matched to the CEREPAK Freeform 3mm x 6cm (D2 = 0.012”, length = 6cm) with 44% greater volume of 4.378mm3. Scenario II: (a) Stryker Target XL 360 12mm x 45cm (D2 = 0.014”, length = 45cm) with volume 44.692mm3 was matched to the CEREPAK Heliform XL 12mm x 42cm (D2 = 0.015”, length = 42cm) with 7% greater volume of 47.884mm3. (b)Stryker Target 360 5mm x 20cm (D2 = 0.010”, length = 20cm) with volume 10.134mm3 was matched to the CEREPAK Freeform 5mm x 15cm (D2 = 0.012”, length = 15cm) with 8% greater volume of 10.945mm3. Conclusions The four selected CEREPAK coils compared to four equivalent Stryker coils achieved higher total coil volume in all scenarios. An increase in PWD by as little as 0.001”‐0.002”, improved relative coil volume by 15%‐44% (with equivalent coil length) and 7–8% (with varied coil length by 3–5cm). Clinicians evaluate many coil characteristics when treating an IA, however, PWD might be given consideration over length due to its impact on total coil volume.