Scanning electron microscopic features of lacrimal drainage silastic stents: Comparison of various Crawford and large-diameter stents

Abstract

Purpose This study aimed to examine the differences in the biofilms and physical deposits on Crawford stents compared to large-diameter stents. Methods A prospective interventional study was performed on a series of patients undergoing external or endoscopic dacryocystorhinostomy (DCR) and endoluminal lacrimal duct recanalization (ELDR) with either Crawford or large-diameter stents. All the Crawford stents were retrieved at six weeks and the large-diameter ones at eight weeks following the surgical intervention. There was no evidence of post-operative infection in any of the patients. Following extubation, standard protocols of scanning electron microscopy were used to assess the biofilms and physical deposits on the stents. Results A total of 15 stents were studied. Of these, twelve were Crawford, and three were large-diameter stents. The Crawford stents were from two different manufacturers. All the stents demonstrated evidence of biofilm formation and physical deposits. The Crawford stents showed thin biofilms and sparse physical deposits, but there were no demonstrable differences amongst stents from different manufacturers. However, the deposits and biofilms were thicker and more extensive in the large-diameter stents than the Crawford ones. The biofilms from all stents showed the presence of polymicrobial communities within the exopolysaccharide matrix. Conclusions The present study found differences in biofilms and physical deposits between Crawford and large-diameter stents. These differences can be partly explained by stent duration, size, and their tissue interactions.