Trigeminal neuralgia (TN) is a debilitating disorder that presents with a sudden onset of severe, unilateral, paroxysmal, and lancinating pain in one or more of the distributions of the trigeminal nerve. Although TN has many causes, neurovascular compression of the trigeminal nerve is a known cause,1 as first suggested by Dandy in 1932 (2).2 TN is analogous to hemifacial spasm (HFS), which is often caused by neurovascular compression of the facial nerve at the root entry zone (REZ).3,4 Effective management is crucial for improving the quality of life (QoL) of patients. Microvascular decompression (MVD) is a primary option for treating TN caused by neurovascular compression, which has attracted much attention compared to other treatment options such as medication, percutaneous rhizotomy, or neurolysis. MVD has been reported as a safe and effective treatment for TN, with a high rate of long-term success.5 However, it still has major limitations, including the risks of TN recurrence, surgical difficulties, and complications due to the complex anatomy.6, 7, 8

To treat TN or HFS caused by neurovascular compression, endovascular approaches such as the deployment of intracranial stents or devices, which are intended to relieve the cranial nerves (CNs) by decompressing the offending vasculature, have garnered recent attention.9, 10, 11 Notably, intracranial stents, as they can be safely delivered and deployed in tortuous and small arteries <2.0 mm in diameter, can be applied to change the path and angle of the offending vessel, including the REZ of the cranial nerve. Chun et al. previously reported the development of a novel intra-arterial neurovascular decompressor (IA-NVD) for neurovascular compression syndrome (NVCS) and successfully demonstrated its functionality and biocompatibility.12 They also suggested that IA-NVD may be a potential device for releasing neurovascular compression of CNs by changing the angles or paths of the offending arteries.12, 13, 14, 15 TN has a common offending artery, the superior cerebellar artery (SCA), which usually compresses the trigeminal nerve superiorly. Therefore, stent deployment from the anterior pontomesencephalic segment of the SCA to the basilar artery can change the course of the SCA upward so that the REZ of the trigeminal nerve can be decompressed (Figure 1).

In the present study, we developed a novel stent, the Transform stent, and evaluated its mechanical properties, such as radial force, trackability, bending stiffness, and conformability to treat TN by changing the course of the SCA and widening the basilar-SCA angle. For comparison, this stent was evaluated against the Enterprise stent (Codman Neurovascular, Miami Lakes, FL, USA), a self-expanding laser-cut closed-cell intracranial stent that can be applied to arteries <2.0 mm in diameter.16, 17, 18