Introduction: Having recently designed an implantable tubular mechanical device-equivalent of an arachnoid granulation, we set out to develop a catheter-based transfemoral venous endovascular delivery system capable of accessing the inferior petrosal sinus (IPS) for delivery and transdural deployment of the shunt device into the cerebellopontine angle (CPA) cistern.
Methods: To provide stability and consistent tracking, an approach was chosen involving transient distal deployment, via 0.027” microcatheter, of a 5 mm diameter stent-anchor in the cavernous sinus, which is connected to a 0.014” flat rail exchange-length wire. The flat rail provides support and orientation of a rapid-exchange 4F dual-lumen penetrating catheter harboring a hollow 20G needle protected by a retractable guard during navigation to the target site and a maximal penetration depth set by tip design. By leveraging the natural IPS angulation near the CPA cistern, the shunt delivery catheter is advanced to the target site of deployment, unsheathing the needle tip in off-axis fashion from the flat rail, penetrating dura, and accessing the CPA cistern.
Results: This approach was performed bilaterally in a series of 4 human cadaver heads affixed by Leksell frame on a biplane angiography table via cannulation of the internal jugular vein using road-map guidance and intra-procedural cone-beam computed tomographic imaging. Following penetration into the CPA cistern, the low-profile shunt device was successfully deployed with its distal tip into the CPA cistern and its proximal tip deployed through the IPS into the internal jugular vein, with visual and radiographic confirmation.
Conclusions: We have successfully demonstrated the proof of concept of a novel endovascular approach to the CPA cistern for CSF diversion using a low-profile minimally invasive transvenous transfemoral delivery system in human cadaver specimens using conventional endovascular imaging and navigation tools. This novel transdural deployment technique may provide for a less invasive endovascular treatment for communicating hydrocephalus.
Patient Care: It is hoped that the presented work will contribute to eventually providing patients a minimally invasive approach for the treatment of communicating hydrocephalus that may improve on the known surgical risks and infection complications associated with conventional ventriculo-peritoneal shunt surgery.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the anatomy of the inferior petrosal sinus and its relationship to the cerebellopontine angle cistern, 2) Discuss the potential for endovascular navigation and transdural deployment of arachnoid granulation mimic at that site using the presented approach, 3) Identify some of the advantages and pitfalls of this approach compared to conventional ventriculo-peritoneal shunt placement