Gas and steam sterilization of assembled versus disassembled laparoscopic equipment. Microbiologic studies

Current recommendations specify disassembly of most laparoscopic equipment prior to sterilization. Surgical technicians, however, are often unfamiliar with the proper assembly of laparoscopic instruments, resulting in possible patient injury from equipment malfunction. Therefore, we tested the hypothesis that disassembled laparoscopic equipment is sterilized more thoroughly than assembled equipment. We inoculated internal sites on laparoscopic instruments prior to assembly with bacterial spores resistant to ethylene oxide and steam sterilization. We also manually cleaned the equipment after inoculation prior to steam sterilization of both the assembled and disassembled instruments. The control instruments were stored at room temperature during test sterilization runs. No vegetative bacteria survived ethylene oxide or steam sterilization in assembled equipment, but despite a significant reduction, spore-forming bacteria could be cultured from the assembled equipment. If the instruments were washed before steam sterilization, there was similar spore clearance in the assembled and disassembled instruments, with both groups attaining a high level of disinfection. Our data suggest that disassembly, cleaning and proper assembly of equipment prior to sterilization present no more risk of infection transmission than does disassembly during prevacuum steam sterilization. The method provides properly assembled and functioning equipment at the time of surgery.