Are bio-degradable stents an option in peptic oesophageal stricture?

Treating resistant peptic oesophageal strictures still poses significant challenge to gastroenterologists and GI surgeons around the globe. Although traditional treatment is repeated endoscopic dilatation, there is no clear evidence regarding their indicated frequency or degree of stretching, required for achieving best results. Patients are mostly in their extremis and malnourished, prone to complications from factors both related and unrelated to interventions. Hence, any possible alternative which reduces number of invasive interventions or increases their intervals are worth exploring. In quest for this, use of steroid injection with endoscopic stretching and stents of different varieties have been investigated. Endoscopic steroid injection to the stricture site was reported initially as a better option over endoscopic dilatation alone, however, in absence of a specified dose of injection, set regime and added risk of delayed perforation is still under review.¹ After several initial reports of complications and low success rates in benign setting with metal and plastic stents (embedding, migration and need for re-intervention), biodegradable stents (BDS) emerged as a more viable alternative. However, studies failed to show success rates of more than 55% with BDS. Most of these studies were prospective or retrospective models, with small cohort size.^2,3,4,5 Most studies used heterogeneous cohorts comprising of strictures from several aetiologies, thus introducing selection bias, as a recent meta-analysis found association between aetiology and treatment outcome in benign strictures.⁶ Different follow-up periods were used to define clinical success in most studies. Hence, inferences drawn regarding success rates were comparable between reports with difficulty. A randomised trial reported inferior performance of BDS with respect to mean number of adverse outcomes, post intervention dysphagia-score at 6 and 12 months as compared to endoscopic dilatation alone, in benign setting (Table 1).⁷ This was also in clear contradiction to reports from non-randomised studies claiming superiority of BDS in providing greater dysphasia free intervals.⁸ The meta-analysis, after analysing results from 444 patients and 18 studies, reported no significant difference between results from plastic or metal stents and BDS in benign strictures.⁶ The authors, however, warned about high levels of heterogeneity in participant studies, especially those involving plastic and metal stents. There was also the obvious risk of amplification of bias from several participant studies which were largely non-randomised.

Lastly, stents are liable to cause more strictures at its ends for reasons not entirely clear to us.⁹ Probably by keeping the gastro-oesophageal junction open at all times, stents promote continued reflux which is the likely contributory factor. This may also be a reason for shorter dysphagia free intervals with sequential stenting in recurrent stricture.¹⁰

Hence, prior to advocating its routine use in benign conditions and replacing current treatment with regular endoscopic dilatations with stents, further targeted studies with larger, non-heterogeneous cohorts, longer follow-up periods and more robust evidence base is required.

Table 1.

http://www.actagastro.org/numeros-anteriores/2018/Vol-48-N1/Vol48N1-PDF09.pdf (html)