The Pipeline Embolization Device, or PED, has revolutionized treatment for unruptured brain aneurysms. A PED is a small cylindrical mesh device that is inserted into an affected artery in a less invasive endovascular procedure. The PED is a relatively safe and effective way to treat aneurysms previously considered too difficult to treat or when other treatment options have failed.
Treatment Options for Cerebral Aneurysm
A cerebral aneurysm occurs when an artery in the brain develops a weak spot. Over time, the pressure of blood flowing through the artery causes that weakened area to balloon outward, forming a bulging area that often resembles a berry on a stem. Some aneurysms stay relatively stable throughout an individual’s life, but others can enlarge and eventually rupture, causing hemorrhagic stroke or even death.
Until relatively recently, aneurysms were treated either by a surgical procedure called clipping, or by coiling, which is a less invasive endovascular approach. In clipping surgery, the skull is opened and a small springy clip is placed directly across the “neck” of an aneurysm to cut off its blood supply. However, clipping poses the usual risks of surgery along with potential complications such as stroke and rupture of the aneurysm.
Coiling requires only one incision into the femoral artery in the groin to direct a catheter to the aneurysm site. There, the aneurysm is packed with fine, flexible platinum wire, which blocks the flow of blood to the aneurysm. Yet coiling has its drawbacks, too. This procedure can cause the aneurysm to rupture, or the coils can become compressed so that blood can enter the aneurysm again.
The Pipeline Embolization Procedure: A New Approach
The Pipeline embolization procedure takes a different approach – flow diversion. This type of procedure is unlike any thus far known aneurysm treatment because it focuses not on the aneurysm itself but on restoring normal blood flow through the parent artery.
Since the Pipeline Embolism Device (PED) is designed to treat an aneurysm indirectly by routing blood through the artery, rather than by direct contact with the aneurysm itself, this procedure can significantly reduce the risk of a rupture.
Approved by the FDA in 2011, the PED is a wire mesh stent that is placed inside the artery at the aneurysm site in an endovascular procedure similar to coiling. Directed to the aneurysm site via a catheter threaded through the artery, the PED opens out against the artery walls, diverting blood to flow as usual past the aneurysm rather than into it. Deprived of its blood supply, the aneurysm eventually shrinks and disappears.
When Is Pipeline Embolization Used?
Pipeline embolization is an effective solution for many aneurysms that pose difficulties for coiling or clipping procedures. Aneurysms can occur in areas of the brain that are difficult to access through surgery and they can have problematic configurations as well.
Although many aneurysms take on the typical “berry” shape with a small neck and a ballooning sac, some of them have a wide neck that can pose problems for both coiling and clipping. Others are very large, creating a greater risk for rupture, while some are too small to clip or coil. Pipeline embolization makes it possible to treat these “difficult” aneurysms.
The Pipeline embolization procedure can also be used to re-treat previously coiled aneurysms in which the coiling “fails.” In some situations, the coils placed into an aneurysm can settle and become compacted, so that blood can accumulate in the aneurysm once again. Placing a PED into the artery at the site itself can resolve the aneurysm completely.
Weighing Benefits and Risks of Pipeline Embolization
The minimally invasive Pipeline embolization procedure typically has a shorter recovery time than surgery. Without complications, people who undergo a Pipeline procedure typically spend no more than a day or two in the hospital. Full recovery takes about one to two weeks and many people are able to return to most of their normal activities within a week or so.
The procedure does have risks including stroke, perforated or damaged arteries, as well as cranial neuropathy, which is a problem with nerves affecting vision, movement and sensation in the face. In some cases, the PED can slip or migrate, leading to the aneurysm not being blocked.
The Pipeline procedure is generally not appropriate for treating a ruptured aneurysm, but in very few selected patients, this may still be the only option for them to best treat their brain aneurysm. Other factors such as age, general health and other co-existing factors can also play a role in determining whether the Pipeline procedure is appropriate.
To reduce the risk of blood clotting, candidates for the Pipeline procedure need to take blood thinning medications both before (for about a week) and after the procedure (for about 6 months), so this option may not be safe for someone with a poor tolerance for those medications.
Flow diversion treatments for cerebral aneurysm are not for everyone. However, studies have shown that the Pipeline embolization device was able to resolve an unruptured cerebral aneurysm in 95.2 percent of patients. For those whose aneurysms were previously considered untreatable, or for those who have had a “failed” coiling procedure, Pipeline embolization offers hope for resolving an aneurysm without the need for further treatment.
