In a Device Safety article ("Keep a Close Eye on Vacuum-Assisted Wound Closure," July 2005), I implied that all negative-pressure wound therapy (NPWT) uses foam as part of the device technology. Although some NPWT devices use foam, other materials can also be used, depending on the manufacturer.

SUZANNE MALLI, RN, BSN

Center for Devices and Radiological Health, Rockville, Md.