The pipeline embolization procedure is a revolutionary, less invasive approach to treating unruptured cerebral aneurysms, including many that were previously considered too difficult to treat. The pipeline embolization device, or PED, offers an effective and relatively safe alternative to aneurysm clipping and coiling procedures, but this procedure is not without risks of its own.
Some risks associated with pipeline embolization devices include blood clots, incision site complications and artery damage.
What Is the Pipeline Embolization Procedure?
An aneurysm occurs when part of the wall of an artery becomes weak and balloons outward, forming a sac that fills with blood. Aneurysms can enlarge or burst, causing a stroke or even death.
Until relatively recently, aneurysms were treated either by clipping surgery, an invasive procedure that involves cutting open the skull and brain to place a clip around the “neck” of an aneurysm, or by coiling, a less invasive endovascular procedure to fill the aneurysm with fine, flexible wire coils to stop its blood flow. For aneurysms that have certain shapes, however, such as those that are very large or very small blisters, these procedures may not be able to close off the aneurysm successfully.
The pipeline procedure takes a different approach involving flow diversion. Rather than treat the aneurysm directly, flow diversion procedures focus on restructuring the artery itself. In a pipeline procedure, a wire mesh sheath called a pipeline embolization device is inserted into the artery at the site of an aneurysm to block its flow of blood. The PED allows blood to flow normally through the artery, so that in the weeks and months after surgery, the aneurysm shrinks and eventually disappears.
Pipeline embolization typically takes around an hour and a half and patients usually recover in the hospital for a day or two before returning home. Complete recovery takes about two weeks, but many patients are able to return to most normal activities in about a week.
Risks of Pipeline Embolization Devices
The pipeline procedure reduces or eliminates some of the risks associated with aneurysm clipping and coiling, but potential complications can occur. Those with health conditions such as hypertension, diabetes or atherosclerosis (hardening of the arteries) are at greater risk of complications of all kinds, while more general risks related to the pipeline embolization procedure include:
Blood Clots
The pipeline procedure raises the risk of blood clots that can close off the affected artery and interrupt the flow of oxygen and blood to the brain. For that reason, anticoagulant, or blood-thinning medications, are used both before and after surgery to reduce the risk of this kind of obstruction.
Stroke
Although the pipeline procedure aims to prevent stroke caused by a ruptured aneurysm, the procedure itself raises the possibility of a hemorrhagic stroke, either during the procedure or shortly thereafter. Pipeline embolization also raises the risk of ischemic stroke, or a stroke caused not only by blood clots, but also by plaque deposits broken loose from the artery wall, or debris from the catheter and the PED itself. People who experience stroke or nerve damage may need long term therapy or medication to manage deficits in functions such as speech, coordination, or vision.
Incision-Site Complications
The only incision made in a pipeline procedure is in the large femoral artery of the groin, where catheters are inserted. This incision site can be at risk for nerve damage, infection or hematoma(when an abnormal collection of blood accumulates outside of the blood vessels). Incision site infections can be treated with antibiotics, and hematomas can be drained if necessary. Incision site nerve damage typically resolves over time, but medication or physical therapy may help if pain persists.
Artery Perforation or Damage
In endovascular surgery, catheters are guided with the help of contrast dyes and highly sophisticated imaging techniques, but the parent artery can become perforated or otherwise damaged during the placement of the pipeline device. This kind of perforation can be managed by moving a balloon through the catheter and inflating it to stop bleeding. Coagulant medications can also be given to help blood to clot quickly at the site.
Cranial Neuropathy
The cranial nerves arise directly from the brain and govern vision as well as movement and sensation in the face. Depending on the location of the aneurysm, cranial nerves can be damaged during the procedure, and this can affect muscles and sensation in the face and jaw. Cranial nerve damage may resolve in a few weeks, but if neuropathy persists, physical or occupational therapy can help to manage the condition.
Movement of the Pipeline Device
After being placed in the artery, the pipeline embolization device can migrate or collapse, raising the risk of blocking blood flow in the parent artery, or leaving the aneurysm vulnerable to rupture again. If the Pipeline device fails to resolve the aneurysm on its own, or becomes dislodged, another procedure to place a second PED or introduce coiling into the aneurysm may be needed.
Risks Can Be Avoided
Although any surgery, especially to the brain, poses risks, some of the risks related to pipeline embolization can be reduced or avoided altogether. Choosing an experienced endovascular surgeon and care team with extensive training in performing pipeline procedures is a key factor in reducing the risk of adverse outcomes.
To reduce the risk of blood clotting, patients typically begin a regimen of anticoagulants such as Plavix in the days before surgery and continue taking these medications in the weeks and months afterward. During the procedure, constant, real-time monitoring of the microsurgical placement of catheters and the PED can reduce the risk of complications such as stroke, nerve and artery damage.
After the procedure, carefully following post-surgery discharge instructions and scheduling follow-ups as recommended helps your doctors identify potential problems and take the appropriate steps to address them. Periodic tests such as MRI and cerebral angiography can check the placement of the pipeline embolization device and monitor the status of the aneurysm.
A pipeline embolization device can resolve up to 95 percent of unruptured aneurysms – including many once considered too difficult to treat by other means. With fewer risks and a shorter hospital stay and at-home recovery time than other alternatives, this minimally invasive procedure can prevent the potentially devastating effects of a ruptured aneurysm. Your doctors and healthcare team will work with you to achieve the best outcome from your pipeline embolization procedure.
