2.1 The Pipeline Flex embolisation device with Shield Technology ('Pipeline'; Medtronic) is a self-expanding blood flow diverter that is placed across the neck of an intracranial aneurysm. While blood flow through the parent vessel is maintained via the device, flow within the aneurysm sac is disrupted, leading to stagnation and eventual thrombosis formation. Pipeline provides a scaffold for endothelial growth leading to the formation of a biological seal and exclusion of the aneurysm from the circulation. 
2.2 Pipeline is a braided, cobalt chromium and platinum stent-like device which is loaded into and delivered via a microcatheter. It is manufactured in lengths of 10–35 mm and is available in different diameters from 2.5 to 5 mm (in 0.25 mm increments). Multiple devices can be used within each other and/or in sequence to increase the overall length of the construct or to increase the metal surface coverage within an aneurysm.
2.3 Pipeline is indicated for use in patients with unruptured, complex intracranial aneurysms, specifically large and giant, wide-necked and fusiform aneurysms. This is the group of patients covered by this guidance. Pipeline may also be used in patients whose aneurysms are unsuitable for standard coiling and/or stenting and for neurosurgical treatment; and in patients for whom previous coiling/clipping procedures have failed.
2.4 The cost of Pipeline stated in the sponsor's submission is £10,171. These costs have been updated in the latest revision of the cost model to £10,450. 
2.5 The claimed benefits of Pipeline in the case for adoption presented by the sponsor are:
A higher rate of complete, permanent occlusion of large/giant intracranial aneurysms compared with coiling and stent-assisted coiling, leading to reduced rates of retreatment and a decreased risk of haemorrhage.
Increased access to treatment for patients with complex intracranial aneurysms. Pipeline offers a new option for treating patients with complex intracranial aneurysms which are not suitable for stent-assisted coiling or surgery, and patients for whom previous interventions have failed.
Patients may experience a resolution of neurological symptoms as a result of relieving pressure on surrounding areas of the brain caused by the mass effect of aneurysms.
Increased long-term vessel patency, preserving blood flow to distal tissues supplied by the aneurysmal artery.
The high rate of complete, permanent occlusion of the target aneurysm with the possibility of reduced need for retreatment and an overall decrease in use of NHS resources.
2.6 Current options for managing complex intracranial aneurysms include coiling, often with concomitant use of stent placement (stent-assisted coiling), neurosurgical clipping requiring craniotomy (with or without bypass procedures), parent vessel occlusion (by open neurosurgery or by endovascular means) and conservative management.