Electron Microscopic Features of Intraluminal Portion of Nasolacrimal Silastic Stents Following Dacryocystorhinostomy: Is There a Need for Stents Without a Lumen?

AIM: The aim of this study was to examine the presence of biofilms and physical deposits within the lumen of silastic nasolacrimal duct stents inserted during dacryocystorhinostomy.

METHODS: A prospective interventional study was performed on consecutive patients undergoing endoscopic dacryocystorhinostomy with Crawford stent insertion. All the patient samples were retrieved 4 weeks after the surgery. None of the patients had any clinical evidence of postoperative infection. The intraluminal portions studied include the distal cut ends and the entire intraluminal surface. The analysis was performed using the standard protocols of scanning electron microscopy. The luminal surfaces were compared against sterile stents that acted as controls.

RESULTS: A total of 7 stents were studied. Five were consecutive patient samples and 2 were sterile stents. The cut ends and intraluminal surfaces of all the patient stents demonstrated evidence of biofilm formation and physical deposits. The luminal cut ends demonstrated extensive deposits and thick mixed biofilms constituted by fungal filaments and bacteria. The entire stretch of intraluminal surfaces showed thin, fine layers of deposits and bacterial biofilms with skip areas.

CONCLUSIONS: Intraluminal surfaces of lacrimal stents harbor physical deposits and mixed biofilms. Because the purpose and functions of stents are not influenced by the presence or absence of its lumen, the use of nonluminal stents may prevent additional surfaces from acting as nidus for microbes.