Outcome study of the pipeline embolization device for treatment of intracranial aneurysms at a single UK institution

Abstract

Highly selected aneurysms treated with a PED in a UK centre have similar occlusion and complication rates when compared to non-UK studies. Again, it appeared that delayed aneurysm rupture remained a risk for PED treatment in large or giant aneurysms. Follow-up with TOF MRA gave similar occlusion results compared to those obtained with DSA in other studies. The influence of neck size on occlusion rate should be examined in future PED studies.

Outcome Study of the Pipeline Embolization Device with Shield Technology in Unruptured Aneurysms (PEDSU)

“…The overall morbidity rate of 6.8% in our study (one peri-procedural and two post-procedural major adverse events in 44 procedures) is similar to a very similar study using previous generation devices (10.0%) 9 as well as the IntrePED study (7.4%) 3 . Two of the major adverse events occurred in giant aneurysms and one in a large aneurysm again highlighting the higher complication risk associated with PED (or any) treatment of large or giant aneurysms (≥ 10 mm).…”

“…Our results are not dissimilar to flow-diverter device studies in general (ranging between 55-95% over various follow-up intervals) 27,28 or the studies described below using PED only. Our study of the first two generations of PED, also using 3D-TOF-MRA follow up, gave similar complete occlusion rates at 6 and 18 months (65.6% and 78.1% respectively) 9 . At the 1-year follow up of the PFLEX study 20 , the complete aneurysm occlusion rate was 81.8%.…”

“…Data on aneurysm size and location were acquired from DSA images (Allura Xper FD, Philips Healthcare, Amsterdam, Netherlands). As in a previous PED study 9 , post-treatment first follow-up was performed typically at 6 months post procedure using 3D-TOF-MRA (SIGNA 1.5 T HDX, General Electric Healthcare; or AERA 1.5 T, Siemens Healthcare GmbH, Germany) with respective TR 23 or 25 ms, TE 2.5 or 7 ms, flip angle 20 or 25 (with ramped pulse), matrix 320 x 224 or 241 x 256, field of view 19 x 19 cm or 18 x 18 cm, slice thickness 1.4 mm (reconstructed to 0.7 or 0.5 mm respectively). If there were new clinical features during follow up, an earlier MR (with MRA) or CT (with CTA) was performed on a case-by-case basis.…”

“…At a median follow-up of 19 months, there was a cumulative 4.7% thromboembolic event rate in the IntrePED study. Although the numbers are too small for a comparative multivariate analysis, a very similar pragmatic study at our center using previous generation PEDs gave a cumulative 10.0% thromboembolic event rate 9 . Taken together, the data from these studies and the current study suggest that there is no reason to refute the in vitro, ex vivo, in vivo (animal and clinical) evidence of Pipeline Shield’s low thrombogenicity.…”

“…All cases were selected following a consensus decision at a neurovascular multi-disciplinary team meeting which included interventional neuroradiologists and neurovascular surgeons. A high neck-to-sac ratio, a high probability of aneurysm recurrence and increased neurosurgical technical difficulty were the factors leading to Pipeline Shield treatment in preference to coiling, stent-assisted coiling or neurosurgery 9 .…”