In Japan, approximately 10–15% of patients with subarachnoid hemorrhage caused by ruptured cerebral aneurysms die before reaching a hospital. More than 50% develop complications, and over half of the survivors are left with aftereffects.

Among the effective treatment for cerebral aneurysms, stent placement—especially the use of flow diverters (FD), which are finely meshed stents with high blood flow-suppressing capabilities—has recently been utilized as a minimally invasive treatment.

However, FD treatment may cause cerebral infarction or even unexpected aneurysm rupture after surgery by blocking normal branching blood vessels. For the reason, it is necessary to select the appropriate stent size according to the structure of the cerebral blood vessels and the shape of the aneurysm. Currently, this selection largely relies on the physician’s experience, which presents a challenge.
Therefore, we have not only developed a new stent designed to maximize flow-diversion effectiveness, but have also proceeded with building a treatment planning program that combines virtual stent functionality with computational fluid dynamics (CFD) functionality. This allows for “visualized” optimization of treatment for each individual case.
Professor Yuichi Murayama, Chief of the Department of Neurosurgery at the Jikei University School of Medicine Hospital, and his colleagues conducted a multicenter clinical trial of the PENTAS stent and Treatment Planning Program (Virtual stent and CFD functions), and in August 2022, the PENTAS stent was approved as a medical device (Medical Device Approval Number: 30400BZX00187000).

The PENTAS stent and Treatment Planning Program will enables safer treatment of cerebral aneurysms, contributes to improved patient quality of life (QOL), and is expected to generate both social and economic benefits through the broader adoption of appropriate stroke care. Moreover, in a domestic market currently dominated by overseas products, we aim to be a pioneer in promoting the spread of domestically produced medical devices in the domestic market.
We are currently working on further products improvements, including the incorporation of advanced materials, with the goal of launching sales in 2025.