High-flow bypass (HFB) treats complex cerebral aneurysms effectively. However, graft-related aneurysm (GA) remains a rare but significant late complication. Clinicians recently utilized stent-assisted coil embolization to treat an enlarging GA in a 50-year-old patient. This case highlights the necessity of vigilant long-term monitoring for bypass patients. Consequently, medical teams must stay prepared for these delayed vascular challenges.

Ten years ago, the patient received a radial artery (RA) graft for a cavernous carotid aneurysm. Although imaging initially showed a small dilation, the patient missed several years of follow-up. Eventually, new scans demonstrated an enlarging saccular aneurysm with a concerning bleb. Notably, the lesion occurred precisely at the anastomotic site. Therefore, the medical team decided on a targeted endovascular approach to mitigate rupture risks.

Benefits of Stent-Assisted Coil Embolization

The physicians navigated the tortuous radial artery graft using a distal access catheter. They deployed an intracranial stent across the anastomosis to provide stable support. Furthermore, this configuration allowed for the secure placement of coils within the aneurysm sac. The procedure successfully achieved complete occlusion while maintaining the patency of the original bypass. This technical success proves that stent-assisted coil embolization is viable even in complex graft anatomy.

This case underscores that GA can emerge decades after the initial surgery. Therefore, patients require consistent medical management and imaging surveillance. Endovascular techniques offer a less invasive alternative to open revision surgery in selected cases. Moreover, stable catheter support is crucial for navigating complex graft anatomy. This illustrative case provides a roadmap for managing similar late-onset complications in neurosurgical practice.

Frequently Asked Questions

Why do graft-related aneurysms form after bypass surgery?

Graft-related aneurysms typically develop due to hemodynamic stress at the anastomotic site or structural changes in the graft vessel over time. Factors like hypertension and surgical wall injury may also contribute to their formation.

How does stent-assisted coil embolization improve outcomes for these patients?

Stent-assisted coil embolization provides a scaffold that secures coils within wide-necked or complex aneurysms. It allows clinicians to treat the lesion minimally invasively while preserving blood flow through the vital bypass graft.

Disclaimer: This content is for informational and educational purposes only... Refer to the latest local and national guidelines for clinical practice.

References

Ota H et al. Stent-assisted coil embolization for a graft-related aneurysm following high-flow bypass: illustrative case. J Neurosurg Case Lessons. 2026 May 25. doi: undefined. PMID: 42184457.

Kumar A, et al. High-flow bypass with radial artery graft for cavernous carotid aneurysm. Asian J Neurosurg. 2020;15(4):678-682.

Potts MB, et al. Rapid Development of an Aneurysm at the Anastomotic Site of a Superficial Temporal Artery to Middle Cerebral Artery Bypass. World Neurosurg. 2019;128:401-405.