The pipeline embolization device (PED) has become a routine firstline option for the treatment of an increasing population of intracranial aneurysms at many neurovascular centers. Intraprocedural complications during PED deployment, or complications associated with migration of the device, are rarely reported problems. Significant mismatch in luminal diameter between the inflow vessel and the outflow vessel or excessive dragging-stretching of the PED have been related to 'watermelon seed' or 'accordion' effects, respectively, resulting in stent migration. Here we present a novel balloon technique that was successfully used to realign an in situ flow diverting stent that had prolapsed into a large aneurysm. This represents a useful salvage technique and should be considered when encountering this potential complication.

Background The new generation of flow diverters includes a surface modification with a synthetic biocompatible polymer, which makes the device more biocompatible and less thrombogenic. Optical coherence tomography (OCT) can be used to visualize perforators, stent wall apposition, and intra-stent thrombus. Unfortunately real world application of this technology has been limited because of the limited navigability of these devices in the intracranial vessels. In this report, we share our experience of using 3D-printed neurovascular anatomy models to simulate and test the navigability of a commercially available OCT system and to show the application of this device in a patient treated with the new generation of surface modified flow diverters. Material and methods Navigability of OCT catheters was tested in vitro using four different 3D-printed silicone replicas of the intracranial anterior circulation, after the implantation of surface modified devices. Intermediate catheters were used in different tortuous anatomies and positions. After this assessment, we describe the OCT image analysis of a Pipeline Shield for treating an unruptured posterior communicating artery (PCOM) aneurysm. Results Use of intermediate catheters in the 3D-printed replicas was associated with better navigation of the OCT catheters in favorable anatomies but did not help as much in unfavorable anatomies. OCT image analysis of a PCOM aneurysm treated with Pipeline Embolization Device Shield demonstrated areas of unsatisfactory apposition with no thrombus formation. Conclusions OCT improves the understanding of the flow diversion technology. The development of less thrombogenic devices, like the Pipeline Flex with Shield Technology, reinforces the need for intraluminal imaging for neurovascular application.

A simultaneous arterial and venous approach has been widely described for the endovascular treatment of dural arteriovenous fistula (DAVFs) and recently for arteriovenous malformation (AVMs). Conventional venous approaches are performed by direct internal jugular puncture or by femoral access. Although complication rates are low, there are potential life-threatening complications that should be avoided. The advantages of radial artery access have been widely proven, nevertheless the use of upper limb veins in neurointervention are rarely reported. We present five cases of the simultaneous arteriovenous approach through the radial artery and superficial veins of the forearm for the treatment of intracranial neurovascular diseases.

The pipeline embolization device (PED) has become a routine firstline option for the treatment of an increasing population of intracranial aneurysms at many neurovascular centers. Intraprocedural complications during PED deployment, or complications associated with migration of the device, are rarely reported problems. Significant mismatch in luminal diameter between the inflow vessel and the outflow vessel or excessive dragging-stretching of the PED have been related to 'watermelon seed' or 'accordion' effects, respectively, resulting in stent migration. Here we present a novel balloon technique that was successfully used to realign an in situ flow diverting stent that had prolapsed into a large aneurysm. This represents a useful salvage technique and should be considered when encountering this potential complication.

Endoluminal reconstruction with a flow diverter device has emerged as a viable and often preferable alternative to traditional techniques for the treatment of intracranial aneurysms. Precise measurement and device selection are mandatory steps when considering flow diverters usage in order to avoid potential complications. In this sense, incomplete wall-apposition has been described as a predictive factor for immediate in-stent and delayed thrombosis after stent use. One significant usage limitation of flow diverter devices is the parent artery diameter, since the maximum opening of the sizes available are recommended for vessel diameters between 5.2–5.75 mm. Here we present the first clinical use of the largest flow diverter available, the 6×50 mm DERIVO embolization device (Acandis GmbH & Co. KG, Pforzheim, Germany), into the arterial circulation for a cervical internal carotid artery endovascular reconstruction. This is a new device for large or fusiform aneurysms requiring flow diversion, especially located in the vertebrobasilar system or extracranial segments.