Comparative Analysis of Unruptured Cerebral Aneurysm Treatment Outcomes and Complications with the Classic versus Flex Pipeline Embolization Devices and Phenom versus Marksman Microcatheter Delivery System: the Role of Microcatheter Choice on Complication Rate

Objective—The second-generation pipeline embolization device (PED), flex, has improved opening and
resheathing ability compared to the first-generation classic PED device. A previously reported single-insti‐
tutional study suggests that the PED flex devices are associated with lower rates of complications. How‐
ever, there was limited discussion regarding the complication rate with respect to microcatheter choice for
PED delivery and deployment. The present study aims to evaluate outcomes of aneurysm treatment with
PED flex versus classic along with the Phenom microcatheter versus Marksman microcatheter.
Methods—A retrospective, IRB-approved database of all patients who received a PED classic or PED
flex device between January 2012 and July 2018 was analyzed. Microcatheter choice, patient demograph‐
ics, medical comorbidities, aneurysm characteristics, treatment information, and outcome data were ana‐
lyzed using univariate analyses.
Results—A total of 75 PED procedures were analyzed. There was no significant difference in major com‐
plications between the PED classic and PED flex. However, those treated using the Marksman microcath‐
eter were more likely to have a major complication (periprocedural hemorrhage or ischemic event; 16.6%
vs. 0%, p = 0.0248) than those treated with the Phenom microcatheter. Within the PED flex cohort, all
major complications were associated with the Marksman microcatheter (p = 0.0289).
Conclusions—The present study does not replicate significantly fewer complications with PED flex but
demonstrates a significant reduction in complications with the Phenom microcatheter. Ultimately, this sug‐
gests multiple factors are involved in achieving positive outcomes and low complication rates in PED trea‐
ted unruptured cerebral aneurysms.