Intracranial contrast transit times on digital subtraction angiography decrease more in patients with delayed...

Delayed ipsilateral intraparenchymal hemorrhage is a rare but serious complication of Pipeline embolization devices. Hemodynamic changes after these devices are not well understood. Prior research has shown that cerebral aneurysms can alter blood flow patterns. However, no prior work had resolved how these changes might relate to delayed hemorrhage. The role of intracranial transit times in this context remains unclear. Some studies suggest that blood flow redistribution may occur after device placement. But the connection to hemorrhage risk is uncertain. This gap motivated a closer look at digital subtraction angiography data to better understand post-treatment hemodynamics.

This study aimed to evaluate changes in intracranial contrast transit times after Pipeline embolization device use. The researchers focused on how these changes differ between patients with and without delayed hemorrhage. They used digital subtraction angiography to measure transit times before and after treatment. The study compared the MCA to ICA transit time ratio in two groups. The goal was to identify hemodynamic patterns linked to delayed intraparenchymal hemorrhage. The researchers also examined how aneurysm size and age might influence these ratios. They hypothesized that lower ratios might indicate increased hemorrhage risk. The study sought to clarify the clinical relevance of these transit time changes.

The researchers analyzed records of patients with distal ICA aneurysms treated with Pipeline embolization devices. They selected regions of interest in the cavernous ICA and MCA using digital subtraction angiography. Contrast transit times were measured using syngo iFlow software. The MCA to ICA transit time ratio was calculated at three time points. The study compared ratios before treatment, after deployment, and during follow-up. Subgroup analysis was performed for patients with and without delayed hemorrhage. Aneurysm size and patient age were also included in the analysis. Statistical methods were used to assess correlations and differences between groups.

The study included 53 patients with ICA aneurysms treated using Pipeline embolization devices. The MCA to ICA transit time ratio decreased significantly after device deployment. The average ratio dropped from 1.22 to 1.13, with a p-value less than 0.01. Patients with delayed hemorrhage had a lower ratio of 1.00 compared to 1.14 in others. The decrease in ratio was 21% in the hemorrhage group versus 4.4% in the non-hemorrhage group. The difference between these subgroups was statistically significant with a p-value of 0.02. Aneurysm size showed a weak correlation with the baseline ratio but not after treatment. Age did not show a significant correlation with the transit time ratio at any time point.

The MCA to ICA transit time ratio decreases after Pipeline embolization device use. This decrease is more pronounced in patients who experience delayed intraparenchymal hemorrhage. The researchers propose that these changes may reflect altered hemodynamics. The study suggests that transit time changes can be detected immediately after device deployment. The findings support the idea that hemodynamic shifts may contribute to hemorrhage risk. The authors emphasize the need for further research into the mechanisms behind these changes. They note that the relationship between aneurysm size and transit time remains unclear. The study highlights the potential for real-time monitoring to improve patient outcomes.