One-way valve bottle contamination rates in the immediate post-functional endoscopic sinus surgery period

Background: Sinonasal saline irrigation has become an accepted practice in the immediate postoperative management of functional endoscopic sinus surgery (FESS) patients. Recent studies have found that valveless delivery systems of sinonasal irrigation are colonized with bacteria. An alternative delivery system uses a one-way valve to reduce saline backflow and may limit bottle contamination. Our sole objective was to determine whether this system in post-FESS patients eliminates microbial bottle contamination. Methods: Eight patients undergoing FESS were given one-way valve irrigation bottles to use immediately after surgery. Bottles were collected after 1 week of use and another set of bottles after an additional week. Endoscopic-directed cultures of the middle meatus were performed at the time of surgery. Returned used bottles were swabbed for bacteria and the valve system of the bottle was analyzed under scanning electron microscopy (SEM) for the presence of bacteria. Results: All sinus swabs collected at the time of surgery grew bacteria with Staphylococcus sp. present in all samples. After the 1st week of use, 5/8 bottles grew bacterial cultures and showed bacterial presence on the valves by SEM. After the 2nd week, 4/5 bottles had positive culture results and also showed bacterial presence on the valves by SEM. Conclusion: Despite commercial claims that the use of valves and limit of backflow into the bottle will eliminate contamination, our study showed that one-way valve delivery systems become contaminated with bacteria after 1 week of use. We also showed that the bottle valves themselves harbor bacteria after 1 week of use.