Beyond endovascular limits: open surgical management of bilateral giant petrocavernous internal carotid artery aneurysms in a pediatric patient.

Bilateral giant petrocavernous internal carotid artery (ICA) aneurysms are extremely rare, and its natural history, treatment response, and prognosis are unknown. Herein, we present the second case of a bilateral giant petrocavernous aneurysm treated with an external carotid artery-radial artery-M2 segment of the middle cerebral artery (ECA-RA-M2) bypass and ICA ligation. A 12-year-old female diagnosed with bilateral petrocavernous ICA aneurysms presented with headache, vomiting, and ptosis on the left eye. Endovascular treatment was not feasible due to financial limitations; hence, she underwent gradual ICA occlusion with a Poppen clamp followed by Hunterian ligation of the left ICA. Six years later, she returned with progressive blurring of vision on the right eye. CT angiography showed significant enlargement of the right ICA aneurysm (25.8 to 51.6 mm) with partial thrombosis. Endovascular treatment was not feasible due to aneurysm length. Hence, a right pterional craniotomy with an ECA-RA-M2 bypass was performed. Intraoperative pressure monitoring confirmed graft patency but inadequate flow. To mitigate ischemic risk, the right ICA was gradually occluded with a Poppen clamp before definitive Hunterian ligation. Postoperative angiography confirmed bypass patency and complete aneurysm exclusion. The patient was discharged without new neurologic deficits; visual status remained stable. Pediatric bilateral petrocavernous ICA aneurysms are exceedingly rare, with limited data to guide therapy. This case illustrates contralateral aneurysm enlargement following unilateral ICA sacrifice, underscoring the hemodynamic burden on the remaining ICA. Long-term surveillance and individualized, multidisciplinary, treatment planning are critical in managing complex aneurysms in this population.