Effect of long-term storage on sterile status of devices in surgical packs

We investigated the effect of the following on the sterile integrity of surgical packs: four wrapping materials (two-ply reusable, nonbarrier wovens, both new and previously used; disposable, barrier nonwovens; and polypropylene peel pouches), dustcovers, two storage locations, and storage times ranging from 2 to 50 weeks. Two hundred sixty-three packs containing stainless steel coupons were prepared, wrapped, sterilized, and stored. Half of the packs were dustcovered prior to storage. At monthly intervals for a year, packs of each type were opened in a laminar flow hood, and the coupons inoculated into trypticase soy broth. The coupon contamination probabilities were 0.019 for reusable, woven packs; 0.017 for disposable, nonwoven packs; and 0.016 for peel pouches. These differences were not significant. The probability of finding a contaminated coupon in any pack after 50 weeks was 0.018. No trend toward increased probability of contamination over time was observed for any of the pack types studied.