AccessPT Channel, PTA Question of the Week

PTA Question of the Week - Wound healing techniques

Which of the following best describes the wound healing technique that uses controlled subatmospheric pressure to remove excess wound fluid from the extravascular space? 
1. Hyperbaric oxygen
2. Intermittent pneumatic compression 
3. PUVA therapy (psoralen plus ultraviolet A irradiation) 
4. Vacuum-assisted closure

The solution will be posted in a few days.