Balloon-Mounted Stents for Treatment of Refractory Flow Diverting Device Wall Malapposition

As indications for flow diversion (FD) have expanded, new challenges in deployment of flow diverting devices (FDDs) have been encountered. We present 4 cases with aneurysms in which deployment of FDDs were complicated by device malapposition and compromised opening in regions of parent vessel stenosis. In all 4 cases, a balloon-mounted stent was ultimately deployed within the FDD.

To describe the use of balloon-mounted stents (BMS) within FDDs for correction of flow-limiting stenosis and device malapposition.

Patients undergoing FD for treatment of aneurysms complicated by refractory flow-limiting stenosis were identified through multi-center retrospective review. Those cases requiring use of BMS were identified. Further investigation in one of the cases was performed with a simulated pulsatile blood flow model.

After attempts to perform balloon angioplasty proved unsuccessful, BMS deployment successfully opened the stenotic parent artery and improved FDD wall apposition in all 4 cases. Simulated pulsatile blood flow modeling confirmed improvements in the distribution of velocity, wall shear stress, oscillatory shear index, and flow pattern structure after stent deployment. One case was complicated by asymptomatic in-stent thrombosis.

In cases of FDD deployment complicated by flow-limiting stenosis refractory to conventional techniques, a BMS deployed within the FD can provide radial support to open both the stenotic device and parent artery. Resulting improvements in device wall apposition may portend greater long-term efficacy of FD. In-stent occlusion can occur and may reflect a thrombogenic interaction between the devices.