Even before microbiological testing, the first two levels of the Northwest Tissue Center’s safety net—careful donor screening and aseptic procurement procedures—greatly reduce the possibility that any contaminated tissues will enter the controlled-environment processing facility. Furthermore, the Tissue Services has earned a high level of respect from medical examiners and coroners throughout the region, so recoveries precede autopsies; many banks recover tissue post-autopsy.

As a result, very few tissues show positive cultures for such pathogenic contaminants as Clostridium sordellii at procurement. With help from University of Washington laboratory medicine experts, the Tissue Services has compiled a list of “unacceptable” organisms. Fewer than three percent of all musculoskeletal tissues recovered in the last five years showed positive cultures for these bacteria and fungi. Tissue Services policies require that these infected tissues be discarded.

This low percentage owes in part to the very first step in the donation process: initial evaluation of the donor. As donation coordinators review information from clinical caregivers, they look carefully for any sign of underlying pathologies, including sepsis, that would compromise an allograft’s safety. Later, coordinators follow up by examining medical records, autopsy reports and medical-history screenings with donors’ next-of-kin.

In addition to donor screening, the Northwest Tissue Services also relies on strict procurement procedures. Certified tissue technologists procure all tissue aseptically in hospital operating rooms or NTC’s class 100 cleanroom, using sterile technique.

Likewise, processing takes place in the cleanroom, where each donor’s tissue is processed separately. Only 0.8 percent of the musculo-skeletal tissues processed in the last five years showed positive cultures for any kind of organism, including normal skin flora and other environmental bacteria. Only 0.1 percent of all musculoskeletal tissue processed tested positive for unacceptable contaminants; these were discarded.

“It’s our intent to prevent the recovery of or to identify and discard, at any one of several levels, any tissue that could possibly transmit infection,” says Margery Moogk, Tissue Services director.