Final answer:
Autolytic debridement is the least damaging to healthy and healing tissue surrounding a pressure ulcer as it uses the body's own mechanisms to remove dead tissue selectively.
Step-by-step explanation:
The type of debridement that causes the least damage to healthy and healing tissue surrounding a pressure ulcer is autolytic debridement. This method utilizes the body's own enzymes and moisture to rehydrate, soften, and finally liquefy hard eschar and slough. Autolytic debridement is non-invasive and selective, as it only targets necrotic tissue and spares the surrounding healthy tissue, making it an ideal choice for treating pressure ulcers.