Randomized Comparison of Laparoscopic LEns Defogging Using Anti-fog Solution, waRm Saline, and Chlorhexidine Solution (CLEAR)

In subjects allocated to the warm saline group, a thermos flask, which was filled with heated sterile water, was used. A 1000 ml bottle of sterile water was heated to 60 ˚C in a stove for an hour at minimum. Just before introducing into the abdominal cavity, the laparoscope was placed into the thermos flask for 30 seconds at minimum . After each incidence of laparoscopic lens fogging (LLF), the scope was briefly inserted into the thermos flask about 10 seconds, and was then wrapped gauze around the lens before abdominal reinsertion.

In the anti-fog agent group, Ultra-Stop TM (Sigmaphrarm, Vienna, Austria), which is a commercial anti-fogging solution containing alcohol, surfactant, and water for medical optical devices, was used. Wiping the lens with gauze soaked in Ultra-Stop TM and allowing the surfactant to act for 5 seconds, the laparoscope was introduced into the abdominal cavity. After each laparoscopic lens fogging (LLF), the scope was removed from the abdomen and cleaned using the same corresponding method.

In the control group, the lens was not wiped gauze or applied any solution before use of the laparoscope. When occurred the event of each laparoscopic lens fogging (LLF) that splatter of irrigation fluid, blood, and body fluids affected visual clearance, the laparoscopic lens was manually rubbed with clean gauze by a scrub nurse.

In the chlorhexidine group, the lens was wiped with gauze soaked in 4% chlorhexidine detergent solution (Firson, Cheonan, Korea) for 5 seconds before introducing into the abdominal cavity, and chlorhexidine was reapplied on the lens at the occurrence of laparoscopic lens fogging (LLF).