From the Guidelines
The main intra-operative procedural risks when treating a brain aneurysm with a Pipeline flow diverting stent include thromboembolic complications, vessel perforation, and hemorrhage, with a case fatality rate of 0.6%, permanent morbidity rate of 7%, and hemorrhage rate of 0.9%. Thromboembolic events are the most common complication, occurring in approximately 3-6% of cases, as the metallic stent surface can activate platelets despite dual antiplatelet therapy 1. Vessel perforation or rupture may occur during microcatheter navigation or stent deployment, particularly in tortuous vessels, with an incidence of about 1-2% 1. Hemorrhagic complications can result from wire perforation or aneurysm rupture during the procedure. Other risks include stent migration or improper deployment, which may require additional stent placement. Vasospasm can occur from vessel manipulation, and contrast-induced nephropathy is possible in patients with renal insufficiency. To minimize these risks, patients typically receive dual antiplatelet therapy (usually aspirin 325mg and clopidogrel 75mg daily) for 5-7 days before the procedure, with platelet function testing to ensure adequate response. During the procedure, heparin administration maintains an activated clotting time of 250-300 seconds. Careful patient selection, meticulous technique, and experienced operators are essential for reducing these procedural complications, as supported by the most recent guidelines from the American Heart Association/American Stroke Association 1. Some key considerations for treatment include patient age, presence of medical comorbidities, and aneurysm location and size, which are strong predictors of perioperative morbidity and rupture risk 1. The use of stent-assisted coiling and flow diverters has a higher risk of thrombogenicity than primary coiling, necessitating dual antiplatelet therapy, and their use in ruptured aneurysms is associated with a higher risk of hemorrhagic complications 1. Aneurysm obliteration within 24 hours of aSAH is likely superior to delayed treatment, particularly >3 days 1. Overall, the treatment of brain aneurysms with Pipeline flow diverting stents requires careful consideration of the potential risks and benefits, as well as meticulous technique and experienced operators to minimize complications.
From the Research
Intra-Operative Procedural Risk
The intra-operative procedural risk when treating a brain aneurysm with a pipeline flow-diverting stent includes:
- Technical complications such as distal wire fracture of the stent delivery system and insufficient stent expansion 2
- Intra-operative hemorrhage or intra-operative thromboembolic complications, although none were reported in one study 3
- Perioperative thromboembolic events, which can be prepared for and treated with adjunctive medical therapy 4
- Minor technical issues without clinical consequence, such as stent migration, stent misplacement, unanticipated stent shortening, and the impossibility to recapture the distal coil tip of the supporting device 5
Morbidity and Mortality Rates
The morbidity and mortality rates associated with the use of pipeline flow-diverting stents for brain aneurysm treatment are:
- Morbidity rate: 0% 6, no permanent morbidity 2
- Mortality rate: 1.3% 6, 2.2% 2, 4% (one fatal nonaneurysmal cerebellar hemorrhage) 4
- One study reported a death due to intracerebral hematoma after thrombolysis 6
- Another study reported a death due to a massive infarct caused by delayed stent thrombosis 5
Complications and Adverse Events
Other complications and adverse events that have been reported include: