# Delayed Iatrogenic Direct Carotid Cavernous Fistula Following Flow Diversion for Aneurysm With Spontaneous Healing: A Case Report

## TL;DR

A rare case of a delayed iatrogenic direct carotid cavernous fistula, caused by a flow-diverting stent for aneurysm treatment, spontaneously healed over months.

## Contribution

This is the first reported case of a delayed iatrogenic direct CCF following flow diversion that spontaneously resolved.

## Key findings

- A delayed iatrogenic direct CCF occurred after flow-diverting stent placement for aneurysm treatment.
- The CCF spontaneously resolved within a few months without intervention.
- This case highlights the rare possibility of spontaneous healing in high-flow CCFs.

## Abstract

An abnormal connection between the carotid artery and cavernous sinus is referred to as a carotid cavernous fistula (CCF). A direct CCF results when the connection occurs between the intracranial internal carotid artery (ICA) and the cavernous sinus. These events are typically the result of a head injury, but can also be iatrogenic, resulting from various intracranial procedures. Direct CCF occurrences rarely heal spontaneously due to the high flow rate across the fistula. In this report, we present an uncommon case involving a delayed iatrogenic direct CCF, which developed following the placement of a pipeline flow-diverting stent that was used to treat a cerebral aneurysm. Interestingly, this unusual iatrogenic direct CCF subsequently spontaneously resolved within a few months. To our knowledge, this is the only case of a delayed CCF occurring with the use of a flow-diverting sent, which then resolved on its own. This report recounts our experience with the case.