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Intreped Results Confirm Safety of Pipeline for Aneurysm Treatment

Posted on April 15, 2014


NeuroNews – April 2014, Issue 13

Results of the multicentre Intreped registry have shown that the Pipeline flow diverter (Covidien) is preferable for the treatment of giant, wide-necked aneurysms over stent-assisted coiling but there are presently not enough data to ascertain whether it is better for aneurysms that are in the posterior circulation

Demetrius K Lopes, director of neuroendovascular surgery at Rush University Medical Center, Chicago, USA, who presented the results at LINC Houston, 9–11 December 2013, Houston, USA, said that previous to the Intreped registry, in the PUFS (Pipeline for uncoilable or failed aneurysms) study, which investigated flow diversion for large and/or giant and wide-necked aneurysms, there was 85.7% aneurysm occlusion rate and a 5.6% morbidity and mortality rate. This was a significant improvement in occlusion rates in comparison to the historical data, in these types of aneurysms.

Therefore, the rationale for initiating the Intreped (a retrospective, multicentre, global registry) was that there was significant debate on the benefit and risk factors of flow diversion as experience was based on multiple small and medium range reports. It was also based on the fact that there was no large-scale multicentre data on the safety of the Pipeline device.

The primary objective was “to determine the incidence of important safety outcomes based on real world experience”. Some of the safety outcomes of the registry included intracranial haemorrhage and ischaemic stroke. Major events were defined as symptoms present after seven days and minor if they were resolved within seven days. This was reported by Lopes to be consistent with PUFS and other published literature.

In Intreped, 793 patients were enrolled and 906 aneurysms were treated. Follow-up (19.3 months) was >3 times longer than in PUFS and more than 88% of patients had a one year or more follow-up period.

The types of aneurysms in Intreped treated with the Pipeline were fusiform (13%), saccular (13%), and dissecting (6%) and ruptured (8.4%). More than 50% of the aneurysms treated were small aneurysms. In Intreped, the average aneurysm size was 10.7 mm and the average neck size was 6.2mm. Multiple Pipeline devices were used in 207/906 aneurysms (22.8%) to achieve an overlap effect for additional length.

The results, according to Lopes, showed that 37% of aneurysms were anterior and less than 10mm, 35% were anterior and over 10mm, 12% were other anterior aneurysms over 10mm, 9% were other anterior under 10mm and 7% were in the posterior circulation.

Intreped vs. PUFS results Total ischaemic stroke was 6.6% (52/793) in Intreped and 4.7% (5/107) PUFS. Major ischaemic stroke was 4.7% (37/793) and 2.8% (2/107), respectively and minor ischaemic stroke was 1.9% (15/793) vs. 19% (2/107), respectively.

The results for intracranial haemorrhage were: total haemorrhage 3% (24/793) 4.7% (5/107), major haemorrhage 2.4% (19/793), 1.9% (2/107) and; minor haemorrhage 0.6% (5/793), 2.8% (3/107).

Neurologic death in Intreped was 3.8% (30/793) and five of these were posterior and six were ruptured aneurysms. Intreped total morbidity and mortality was 8.3% (66/793).

According to Lopes, flow diverters performed better in giant aneurysms in the safer, anterior, proximal circulation in the long-term than stenting and coiling. He said: “It is an easy choice” to use flow diverters in this type of aneurysm. However, he noted that problems remain in treating posterior circulation aneurysms as they are associated with an increased risk of complications irrespective of treatment choice.

“Although we do not have a head-to-head trial”, Lopes said, “Flow diverters are a better treatment than stent-assisted coiling for large and giant anterior circulation aneurysms. However, he concluded that: “The jury is still out” when it comes to using flow diverters in posterior circulation aneurysms.