Intro: Necrotizing and soft tissue infections (NSTI) are life-threatening bacterial infections characterized by subcutaneous tissue, fascia or muscle necrosis. The hospital mortality of NSTI is high, comprised between 20 and 30%. NSTIs represent the 4th cause of septic shock. Early management of NSTIs requires a coordinated and multidisciplinary approach, including broad-spectrum antibiotic administration, management of organ failures and aggressive surgical debridement with excision of all necrotic and infected tissues. NSTIs involve the lower limbs in about 70% of cases and lead in 15% of cases to limb amputation. During the early post-operative phase, daily wound care is required using conventional dressings. As soon as the infectious process is controlled, typically within 7 to 10 days of the initial debridement, the main goal of wound dressing is to allow for a granulation tissue to develop so that to perform a skin grafting. Negative pressure wound therapy (NPWT), which consists in applying a negative pressure on the wound surface, may be used to this effect. A dedicated dressing is connected to a device that generates a negative pressure and collects exudates. NPWT may have a positive effect on wound healing by removing exudate, increasing regional perfusion and patient comfort and reducing infections. Beneficial effects of NPWT have been suggested by case series. However, no randomized controlled trial are currently available to adequately assess its efficiency and the 2014 guidelines of the Infectious Diseases Society of America (IDSA) on NSTI did not provide recommendations regarding NPWT use for managing NSTI wounds. The study's hypothesis is that in patients managed for NSTIs, NPWT: 1) may accelerate skin grafting and complete wound healing; and 2) improve functional outcomes.

Hypothesis/Objective: To demonstrate in patients who underwent a surgical debridement of the lower limb for NSTI a superiority of a wound dressing strategy using NPWT (intervention) as compared with conventional wound dressing on local healing (complete) and the recovery of walking.

Method: Open-label randomized controlled trial with blinded assessment of the primary end point. Randomization in two arms: experimental group (NPWT) versus control group (conventional dressing) until skin grafting (decided by the attending surgeon).

Inclusion Criteria:

• Age ≥ 18 years
• Written informed consent
• NSTI/NF of the lower limb clinically suspected and confirmed by surgery with a first debridement performed since 5 days or more
• Infection considered controlled (i.e., no more surgical debridement is necessary)
• Last debridement performed at least 72 hours before
• Affiliation to a social security system

Exclusion Criteria:

• Limited life expectancy
• NPWT already initiated for the current NSTI/NF episode
• 1st surgical debridement performed less than 5 days or more than 15 days before
• High risk of bleeding (blood vessels exposed)
• Local neoplasia
• Risk of organ or peripheral nerve injury
• Impossibility to set up a NPWT dressing hermetically
• Limb amputation
• Patient unable to walk without help
• Women who are pregnant or are breast-feeding, or are of childbearing age and do not use or do not plan to use acceptable birth control measures
• Patients under legal protection
• Prisoners

This committee comprises experts (a dermatologist, a plastic surgeon, and a nurse specialized in wound care) tasked with validating in a consistent manner, blinded to the randomization arm, the aspect of the primary endpoint relating to cutaneous healing, based on standard photographs taken on a weekly basis by the clinical research nurse. Photographs will be made available to members of the adjudication committee through an online platform (Dispose AP-HP) or a digital support.