# Surgical Treatment of Two Simultaneous De Novo Para-Anastomotic Aneurysms Following Side-to-Side Bypass of Anterior Cerebral Artery: A Technical Case Instruction

## TL;DR

A rare case of two new aneurysms after a brain artery bypass surgery is successfully treated with a modified surgical approach.

## Contribution

Presents a novel surgical strategy for managing simultaneous de novo para-anastomotic aneurysms after cerebral artery bypass.

## Key findings

- Modified trapping and bypass successfully treated two simultaneous para-anastomotic aneurysms.
- Long-term follow-up is essential after cerebral artery bypass procedures.
- Complex surgical techniques are required to secure aneurysms and maintain blood flow.

## Abstract

Anterior cerebral artery aneurysms requiring bypass are rare; thus, the literature regarding the subsequent pathology related to the procedure is severely lacking. Hence, there is no consensus regarding the management strategy. The progressive enlargement of de novo para-anastomotic aneurysm carries a higher rupture risk of this abnormal vessel. The peculiar location, related vascular territory, and small corridor of interhemispheric fissure pose challenges to its management.

We present a 70-year-old woman with two simultaneous de novo para-anastomotic aneurysms after an A3-A3 bypass. Previously, she had an A3-A3 bypass and aneurysm trapping of left A2 dissecting aneurysm 7 years ago. On routine follow-up imaging, she had progressive enlargement of two aneurysm-liked lesions on top of anastomosis vessels. She underwent a modified trapping and superficial temporal artery-anterior cerebral artery bypass with excellent clinical outcome and no recurrence.

Managing de novo aneurysm formation after in situ A3-A3 bypass is challenging. Complex procedures are required to secure the aneurysm from circulation and ensure its vascularization at the distal site. Long-term follow-up is necessary for all bypass procedures.