Introduction During angiography, the contrast bolus injected into a vessel can cause substantial changes in baseline pressures and flows.¹ There have been sparse case reports about aneurysmal re-bleeds during angiography.² A physician survey of injection rates used during angiography showed that 81% of respondents considered the impact of injection rate on aneurysm rupture to be negligible .³ The goals of this study were to record intraneurysmal pressure changes during contrast injections and to evaluate the effect of injection conditions on intraneurysmal pressure changes.

Methods A silicone replica of a complete circle of Willis model with ophthalmic, anterior communicating, and basilar tip aneurysms was connected to a pulsatile flow pump (Vascular Simulations, Stony Brook, NY, figure 1). Catheters were placed in either the right internal carotid or right vertebral artery and a total of 144 injections were performed by varying 4 different parameters: Catheter Size, Injection Rate, Injection Time, mean Baseline Blood Flow rate (table). The effect of each of the four injection parameters on percentage increase in aneurysm pressures was statistically assessed using ANCOVA; baseline pressure was considered a covariate.

Results The mean intraneurysmal pressure during injection (84.5±10.8 mmHg) was significantly higher than the mean pressure before injection (80.4±10.6 mmHg) (p<0.0001). The percentage increase in mean and systolic aneurysm pressures was 5.1±3.6% and 3.4±2.6%, respectively. The percentage increase in aneurysm pressure was significantly greater (p<0.0001) at high Injection Rates versus low Injection Rates (6.6±4% versus 3.7±3%). Increase in aneurysmal pressure was also significantly affected by Catheter Size in most of the statistical comparisons (p<0.0001). Injection Time (p>0.2) and Baseline Blood Flow rate (p>0.3) had no significant effect on the increase in intraneurysmal pressure.

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Abstract E-210 Figure 1

Conclusion Our results suggest that higher contrast Injection Rates can significantly increase intraneurysmal pressures during angiography. Whether a ~5% increase in intraneurysmal pressure can cause aneurysm rupture needs to be evaluated. Angiography studies need to be conducted in vivo to verify these findings.

References

1. Kovarovic B, et al. Cardiovasc Eng Technol 2018;9(2):226–239.

2. Celtikci P, et al. Turk Neurosurg 2018;28(6):1009–1012.

3. Yousem, DM, et al. AJNR 2001;22:1838–1840.

Disclosures S. Marfoglio: 5; C; Vascular Simulations, Inc. B. Kovarovic: None. W. Hou: None. D. Fiorella: 4; C; Vascular Simulations Inc. C. Sadasivan: 2; C; Vascular Simulations Inc. 4; C; Vascular Simulations Inc. 6; C; Vascular Simulations Inc.