Reply to Dutau et al.

Abstract

We thank Dr Dutau et al. [1] for their comments regarding our article ‘Novel biodegradable stents in the treatment of bronchial stenosis after lung transplantation’ [2]. In our previous experience, there was a place for both metal and silastic stents in tracheal and bronchial stenosis management, as the authors suggest. Silicone stents were used at our institution in the era before biodegradable stenting. Between January 1997 and January 2005, we performed 98 lung transplants in 67 patients (36 single-lung transplants and 31 bilateral-lung transplants). Four bronchial anastomotic complications requiring stenting (4.1%) occurred in four patients (6.0%). All were successfully treated with silicone–Dumon stents, which were removed at the end of the treatment. Due to our close cooperation with general surgeons, we were confronted with excellent results of biodegradable oesophageal stenting. After the appreciation of laboratory and ongoing animal studies [3], we decided to switch from silicone stents to biodegradable stents. We strongly believe that controlled biodegradation of stents is the future of any stenting, not only in airways. As our study was the very pilot study, we were limited in resources, patient population and of course experience. Currently, more biodegradable stents are available and the period of time for which the stents keeps its sufficient resistive radial forces could be chosen. We do not know if a multiple stent placement for a short period of time is superior to the single stent placement for a longer period of time with all concomitant risks (necrosis, granulation, displacement and complicated removal). This is an issue, which should be addressed in a multicentre trial, which is indeed inevitably needed. Currently, at our institution, we cannot justify the use of silicone stents in benign airway stenosis. Hence, we do not plan to conduct a prospective comparative study. Nevertheless, we feel that more evaluation is needed in designing, manufacturing and in vitro testing of polydioxanone biodegradable stents. Meanwhile, the use of these stents (currently not European Conformity marked) remains highly specifically indicated, although the recent results show high safety, efficacy and biocompatibility. First reports of biodegradable stenting in children (another challenging population with growing airways) were published by our colleagues from Great Ormond Street Hospital in London [4] and one prospective study is conducted in Hannover. To summarize, Dutau et al. are kind in their comments on the place of our work in the development of this field. We agree that future phase III trials of absorbable, and other new stents such as drug-eluting devices, should be compared with both metal and silastic stents, the gold standard comparator carefully chosen depending on the clinical setting. International collaboration in the design and conduct of these trials is essential, and for this reason, we fully welcome this debate and interest.