Introduction/Purpose The Penumbra Coil 400 (PC 400) is a new generation of platinum coils with a larger primary diameter (0.020″) than conventional embolic coils (0.010″–0.015″), requiring a larger diameter microcatheter for delivery. The Penumbra PX 400 Microcatheter has a 0.025″ ID lumen and 2.8F distal OD. This is somewhat larger than microcatheters that have been conventionally used to access aneurysms and deliver embolic coils (up to 0.021″ ID lumen and 2.3F distal OD). Compared with conventional microcatheters which use stainless steel reinforcement, the PX400 has a Nitinol coil reinforcement and, in addition, has a softer polymer construction at the distal tip. The PX400 takes advantage of the softness of Nitinol. These innovations combine to produce a catheter which is very soft yet very stable within an aneurysm. The goal of this investigation was to compare the properties of the PX 400 with conventional microcatheters for embolization of intracranial aneurysms.

Materials and Methods The PX 400 Microcatheter was used in eight endovascular cases for Penumbra coil delivery for treatment of intracranial vascular lesions by a single operator with 15 years of neuroendovascular experience. This includes one post-traumatic CCF and seven brain aneurysms. In the aneurysm group, there were two basilar aneurysms, one vertebral aneurysm, two A-comm aneurysms, one MCA aneurysm, and one P-comm aneurysm. In our series, balloon remodeling was used in one case; two cases required a Neuroform stent used with a microcatheter being advanced through the stent, and in two cases an Enterprise stent was used with a PX 400 catheter being jailed. The standard 014 wire was used for all cases, SilverSpeed (ev3/Covidien) or Syncro² wire (Boston Scientific). A two-guide support system was used, a 6F Chaperon (Microvention) and an 8F Neuron MAX (Penumbra).

Results In all cases, the PX 400 Microcatheter reached its intended target, and the coil delivery was uneventful. The catheter crossed a Neuroform stent without difficulty. Jailing technique with an Enterprise stent was favored, but a Neuron Max had to be used to fit a Prowler Plus and a PX 400 together. The overall responsiveness and tractability as well as stability of the new catheter are excellent even in a very tortuous anatomy.

Conclusion Results confirmed that the larger PX 400 microcatheter had tracking, aneurysm entry, coil delivery, stability, and safety characteristics very similar to conventional microcatheters used for the embolization of intracranial aneurysms. Thus, the technology and material engineering represented in the PX 400 redefines microcatheters for treatment of aneurysms and may enable a significant advancement not previously possible with conventional coil treatment.

Competing interests None.