The technology

Danis stent (Ella CS) is a medical device intended to stop acute bleeding from oesophageal varices. It is a removable and self-expandable, silicone-covered nitinol stent which controls bleeding by direct compression of oesophageal varices. The stent is 135 mm long and 25 mm in diameter (30 mm when inflated). It comes preloaded in a balloon-style delivery system that is designed to allow accurate positioning at the gastro-oesophageal junction. The delivery system allows insertion of the stent into the lower oesophagus without radiological or endoscopic assistance. Radiopaque markers at the distal ends and midpoint of the stent allows its position to be confirmed by chest X-ray after the procedure. The Danis stent has retrieval loops with gold markers at both ends which allow the stent to be removed under endoscopic and fluoroscopic guidance using a specifically designed removal device (Ella Extractor). This can be purchased by the company. The stent will need to be removed whether or not the patient has definitive treatment, such as a transjugular intrahepatic portosystemic shunt (TIPS). If TIPS has been done (and portal hypertension is no longer a concern), the company states that the stent can be removed under endoscopic guidance using grasping forceps without fluoroscopic guidance. The Ella Extractor would only be needed to remove the stent in patients who have not had definitive treatment. Danis stent is currently available as part of a basic procedure pack which contains the stent (preloaded in the delivery system), guide wire and syringe.

Current care pathway

In patients with oesophageal varices, haemorrhage is common and can lead to life-threatening bleeding and complications. Bleeding from oesophageal varices are a major complication caused by portal hypertension and mainly happen in people with underlying liver disease. Current standard care for people with acute variceal bleeding involves a combination of basic resuscitation, vasoactive drugs, prophylactic antibiotics and endoscopic techniques. NICE's guideline on acute upper gastrointestinal bleeding in over 16s recommends offering terlipressin to people with suspected variceal bleeding at presentation. Band ligation is the recommended primary therapy for people with upper gastrointestinal bleeding from oesophageal varices, and TIPS is recommended if bleeding from oesophageal varices is not controlled by band ligation. NICE's interventional procedures guidance on stent insertion for bleeding oesophageal varices states that there is enough evidence to show that stent insertion is effective for people with oesophageal varices in whom other methods of treatment have failed to control bleeding.

The British Society of Gastroenterology's UK guidelines on the management of variceal haemorrhage in cirrhotic patients recommend doing upper gastrointestinal endoscopy as soon as the patient is haemodynamically stable to locate the site bleeding. Variceal band ligation is recommended as the first-choice therapy to control bleeding. If banding is difficult because of continued bleeding or this technique is not available, endoscopic variceal sclerotherapy should be done. In case of bleeding that is difficult to control, the guidelines recommend inserting a temporary balloon tamponade (a Sengstaken-Blakemore tube) as a bridge to more definitive treatment such as further endoscopic treatment, TIPS, or surgical treatment. The guidelines state that, ideally, variceal bleeding should be treated in a unit where the staff are familiar with managing bleeds and where routine therapeutic interventions can be done.

The Baveno VI consensus report (Journal of Hepatology, 2015) states that evidence on self-expanding oesophageal metal stents (SEMS) suggests that they are as effective and a safer option than balloon tamponade.

Innovations

The company states that Danis stent can be used without endoscopic image guidance, which may allow for more rapid control of variceal bleeds in emergency situations compared with balloon tamponade. The delivery system has a security pressure valve that prevents the gastric balloon from being inflated in the oesophagus, which may help minimise the risk of oesophageal perforation. It can stay in place for up to a week (compared with balloon tamponade, which should not be left in place for more than 24 to 36 hours). This may allow more time to plan definitive therapy or secondary prophylaxis before removal, as well as increasing the stabilisation period for improvement in liver function. The Danis stent lumen allows oral nutrition to be maintained, which is an important element in recovery, and its variable weave stent body is designed to conform to oesophageal peristalsis, with the aim of preventing stent migration.

Population, setting and intended user

Danis stent is intended to be used as an alternative to balloon tamponade and early TIPS in people aged 16 years and over with acute refractory variceal bleeding. The technology is intended to be used in secondary care by gastroenterologists, hepatologists, emergency care practitioners, paramedics or nurse practitioners. The company highlights that training and education would be needed to make sure healthcare professionals were confident using the technology in an acute setting. Training for consultants and nursing staff is provided by the company free of charge at agreed intervals. Training sessions are in-person and can last between 1 hour and a full day depending on centre needs and frequency.

Costs

Technology costs

Danis stent procedure pack basic (containing stent, preloaded in the delivery system; guide wire and syringe) costs £1,495 (excluding VAT). The procedure cost for inserting the stent is £6,443, according to the 2019/20 national tariff payment system (HRG FD03A Gastrointestinal Bleed with Multiple Interventions, with CC Score 5+). HRG FD03A covers all care costs associated with the procedure and includes more than the cost of the device. The cost of the Ella Extractor, for atraumatic removal of the stent, is £695 (excluding VAT); this would only be used in people who have not had definitive treatment, such as TIPS.

Costs of standard care

The company states that the typical cost of standard care (Sengstaken-Blakemore/Minasota tube 4 lumen) is £300. The cost of the procedure would be the same as that for Danis stent; £6,443 (HRG FD03A Gastrointestinal Bleed with Multiple Interventions, with CC Score 5+). HRG FD03A covers all care costs associated with the procedure and includes more than the cost of the device.

Resource consequences

According to the company, the technology is currently being used by over 20 NHS centres. The company claims Danis stent is likely to lead to cost savings because it can remove or minimise high dependency hospitalisation as well as reduce the demand on fluoroscopic imaging facilities. However, there is no relevant published evidence to support this. The technology has been associated with a substantially lower incidence of device-related serious adverse events compared with balloon tamponade (Escorsell et al. 2016). This could potentially lead to fewer repeat hospital visits and interventions needed for procedural complications, although this has not yet been proven.