High-flow bypass surgery using a radial artery graft for an extracranial internal carotid artery aneurysm: Case reports and literature review

BACKGROUND: Extracranial carotid artery aneurysms are rare. Surgery may be difficult when vessels are tortuous and on a high cervical level. We report two patients whose tortuous extracranial internal carotid artery (ICA) aneurysm located on a high cervical level was successfully treated by ICA ligation and a high-flow bypass using a radial artery (RA) graft between the external carotid- and the middle cerebral artery. CASE DESCRIPTION: (Case 1) A 47-year-old man suffered a recurrent cerebral infarct despite medical treatment. His right extracranial ICA aneurysm measured 33 mm; it was tortuous and located at a high cervical level. We ligated the ICA after placing a high-flow bypass using an RA graft. The aneurysm was not repaired. (Case 2) A 59-year-old woman noticed pulsatile swelling on her left neck. It was due to an extracranial ICA aneurysm that was large (36 mm), tortuous, and located at a high cervical level. We performed ICA ligation after placing a high-flow bypass using an RA graft without direct aneurysmal repair. Six months after the operation she noted a pulsatile bulge on the left oropharynx. We confirmed recurrence of an aneurysm from retrograde blood flow and performed internal trapping by occluding the distal portion of the ICA aneurysm using an intravascular procedure. CONCLUSION: ICA ligation after placing a high-flow bypass with an RA-graft is a technically demanding, but safe procedure to address extracranial ICA aneurysms that are tortuous and located at a high cervical level.