Nanofat on Wound Healing and Scar Formation (NFWHSF)

This study will evaluate the effectiveness and safety of intradermal injection of Nanofat on wound healing and scar formation.

In this monocentric, randomized, controlled, double-blinded prospective interventional study, twenty patients will be included. Each patient will be his/her own control. Patients undergoing DIEPflap breast reconstruction will be included in this study. During the surgery, the abdominal incision will be divided in two equal sides with the umbilicus as midline reference. The sides will be randomized in a treatment side and control side. The treatment side will receive intradermal nanofat injections after the subcutaneous and right before the intradermal sutures. The patient and investigators will be blinded for the treatment protocol. The effects on wound healing, adverse events, scar formation and pigmentation will be evaluated up to one year after the surgery.

Scars, Delayed Wound Healing, Hypertrophic Scar, Post Inflammatory Hyperpigmentation, Donor Site Complication

adipose derived stem cells, stromal vascular fraction, wound healing, scar formation, donor site morbidity, nanofat

Patient, investigator, outcome assessor will be blinded for which side of the scar was treated and which was a control. Only the surgeon, who will not be involved in the assessment, will not be blinded.

This side of the scar received intradermal injection of nanofat during the closure of the donor site.

Lipoaspirate, harvested during the surgery, is centrifuged for 1 minute at 2000 rpm to discard infiltration fluid. The residual fat is passed back and forth between two 10cc syringes interlocked with Tulip connecting pieces (2.4, 1.4 and 1.2 diameter, each 10 passes for a total of 30 passes). This is injected intradermally before the intradermal sutures are placed. The donor site is always entirely sutured (both sides) by the same person.

The abdominal scar will be evaluated clinically by the patient and observer scar assessment scale, starting from one month after the surgery

The time for the abdominal wound to heal will be registered. Wound healing is considered a closed and non-dehiscent wound witout signs of inflammation or infection.

Evaluation of the histological differences of the treatment arm vs. control, by evaluating scar properties on tissue biopsy. Scar thickness, collagen arrangement and angiogenesis will be evaluated.

Evaluation of the Pigmentation Index difference in the treatment arm vs. control arm will be measured by the use of a mexameter, starting from one month after the procedure (after wound healing is complete).

Evaluation of patient satisfaction over the entire course of the study by filling in a Visual Analog Scale, with 1 being very unsatisfied and 10 being very satisfied.

Inclusion Criteria: - scheduled for DIEP-flap breast reconstruction surgery at our department Exclusion Criteria: smokers use of cortisone or other immunsuppressants diabetes mellitus type 1 or 2 age connective tissue disease