Biodegradable oesophageal stent

Benign oesophageal strictures are caused by disorders such as peptic strictures, caustic ingestion, oesophageal surgery and radiotherapy. Such strictures have a negative impact on the quality of life of the patient and can lead to complications such as malnutrition, weight loss and aspiration. The standard treatment for benign oesophageal strictures is endoscopic dilation with balloons. However, there is a wealth of published data that indicates that as many as 10% of patients will not experience any meaningful improvement after endoscopic dilation.1-3 Removable self-expandable metallic stents (SEMS) and self-expanding plastic stents (SEPS) are also commonly used to manage benign oesophageal strictures. There is now an alternative biodegradable polymer stent available which offers the benefit that there is no need for its removal. The BD stent is made from woven monofilament polydioxadnone, the same biodegradable polymer used to produce dissolvable sutures. It begins to degrade at around 6-8 weeks and will start to lose its compression within the oesophagus. At around 11-12 weeks it should have fully degraded. “Currently the stent is indicated for benign strictures of the oesophagus,” said Matt Russell, marketing manager at UK Medical, the UK distributor for the product. “Although no large randomised control trials have yet been undertaken, there is a body of published articles looking at the efficacy and safety of biodegradable stents for refractory benign oesophageal strictures. Repici A et al,4 for example, documents the results of a study of 21 patients undertaken across two European endoscopy centres. This study concluded that all patients showed an improved dysphagia score, from 3 to 1 and nearly 50% required no further intervention. The authors of the study commented that the use of the BD stent may be a valuable alternative to repeat endoscopic dilation. Another study undertaken by Boeckel, Vleggaar and Siersema,5 compared the use of temporary SEPS and biodegradable (BD) stents for patients with refractory benign oesophageal strictures. This study followed two groups of patients who underwent SEPS placement for a period of six weeks and those who were fitted with a BD stent. The study concluded that both SEPS and BD stent placement can achieve longterm relief of dysphagia without further intervention in a third of patients. However, it was noted that BD stents had the advantage over SEPS that fewer procedures are required as the BD stent does not require the removal procedure that is necessary for the SEPS. Although the study considered BD stent placement to be an interesting treatment option, it also concluded that an ideal strategy still needs to be defined.

Clinical feedback

In the UK, the stent has, so far, been used at over 130 hospitals. Feedback from clinicians that have used the technique indicate that it could offer benefits to the NHS through a reduction in the number of hospital visits for patients suffering from oesophageal strictures. Mr Russell explains: “Patients suffering from a stricture in the oesophagus generally need to go into hospital to undergo balloon dilatation of the oesophagus every few weeks. The BD stent can offer a longerterm solution. Loading of the BD stent into the delivery system is a little different to that of traditional metal stents, which generally come pre-loaded. The BD stent has to be manually loaded into a pull-back delivery system immediately prior to insertion. This is because the polymer material does not have the memory forming capabilities of metal stents. If it is loaded into the delivery system too far in advance of insertion, it will not reform to the correct shape in the oesophagus.