Can a cerebral aneurysm be clipped after a failed flow diversion treatment with a device such as a Flow Re-direction Endoluminal Device (FRED)

From the Guidelines

Yes, a cerebral aneurysm can be clipped after a failed flow diversion treatment with a device such as a Flow Re-direction Endoluminal Device (FRED), though this represents a more complex surgical scenario. When flow diversion devices like Pipeline, Surpass, or FRED fail to adequately treat an aneurysm, microsurgical clipping remains a viable salvage option 1. The decision to proceed with clipping depends on several factors including the aneurysm's location, size, and morphology, as well as the patient's overall health status.

Key Considerations

• The presence of the flow diverter within the parent vessel complicates the surgery, as the surgeon must work around this device while securing the aneurysm.
• The procedure typically involves a craniotomy to access the aneurysm, careful dissection around the flow diverter, and placement of a titanium clip across the aneurysm neck while preserving blood flow through the parent vessel.
• This approach requires significant neurosurgical expertise, particularly at high-volume cerebrovascular centers, as emphasized by guidelines for the management of patients with unruptured intracranial aneurysms 1.
• Patients should understand that the complication risks may be higher than with primary clipping due to vessel wall changes, inflammation, and adhesions that can develop after flow diversion therapy.

Recovery and Follow-Up

• Recovery typically involves ICU monitoring for 1-2 days followed by 3-7 days of hospitalization.
• Follow-up imaging at regular intervals is necessary to confirm successful aneurysm obliteration, as recommended for patients undergoing coiling or clipping of a ruptured aneurysm 1.
• The choice between clipping and coiling should be based on a multidisciplinary discussion considering both surgical and endovascular approaches, taking into account the patient's and aneurysm's characteristics 1.

Evidence-Based Decision Making

• The most recent guidelines suggest that coiling is now recommended over clipping to improve 1-year patient outcomes for ruptured aneurysms, but this does not directly apply to the scenario of failed flow diversion treatment 1.
• The decision to clip after failed flow diversion should prioritize the patient's overall health status, aneurysm characteristics, and the potential risks and benefits of the procedure, in line with recommendations for the management of patients with unruptured intracranial aneurysms 1.

From the Research

Cerebral Aneurysm Clipping After Failed Flow Diversion Treatment

• A cerebral aneurysm can be clipped after a failed flow diversion treatment with a device such as a Flow Re-direction Endoluminal Device (FRED) 2.
• The study by 2 presents a multicenter series of 13 aneurysms for which flow diversion failed and were subsequently treated with open surgery, including aneurysm clipping and parent vessel reconstruction.
• The patients underwent aneurysm clipping and parent vessel reconstruction, decompression of the aneurysm mass, occlusion of proximal flow to the aneurysm, or aneurysm trapping with or without extracranial-intracranial artery bypass 2.
• Microsurgical salvage options require individualized care tailored to the underlying pathological features, patient characteristics, and surgical expertise 2.

Flow Diversion Treatment Outcomes

• Flow diversion treatment has been shown to be effective in treating certain types of aneurysms, but it may not be effective for all types of aneurysms 3, 4, 5, 6.
• The study by 3 found that flow diversion was safe and effective in treating fusiform middle cerebral artery aneurysms, but not as effective in treating bifurcation aneurysms.
• The study by 5 found that flow diversion for the treatment of intracranial bifurcation aneurysms had a modest efficacy and relatively unfavorable safety profile.
• The study by 6 found that the use of flow-diverter devices is advisable mainly for unruptured aneurysms, particularly those located at the internal carotid artery or vertebral and basilar arteries, for fusiform and dissecting aneurysms and for saccular aneurysms with large necks and low dome-to-neck ratio.

Considerations for Clipping After Failed Flow Diversion

• Clipping after failed flow diversion treatment should be considered on a case-by-case basis, taking into account the individual patient's characteristics, aneurysm morphology, and the reason for flow diversion failure 2.
• The decision to clip after failed flow diversion treatment should be made by a multidisciplinary team of experts, including neurosurgeons, neuroradiologists, and neurologists 2.