3-D Imaging Assessment of Scar Formation and Would Healing in Fat Grafted vs Non-Fat Grafted Facial Reconstruction Wound Sites

A variety of local and regional skin flaps are used for reconstruction of skin defects on
the face with the intention of full wound closure, healing, and scar minimization. Scarring
is an unavoidable consequence of wound healing, especially after significant facial
reconstruction. Fibroblasts migrate to the injurious site where they proliferate and deposit
collagen. The collagenous proteins serve to fill in the wound defect and allow epithelial
cells to accumulate and repopulate the skin surface. The collagenous base is subsequently
exchanged for various types of collagen and is crosslinked. Although scar formation is an
important component of wound healing, patients develop scars differently based upon location
and biology of the subject. Excessive scar formation may result from excessive collagen
production and inadequate collagen remodeling (Gurtner).

Much effort has focused on minimizing scar formation. Such techniques have included rigorous
sterilization techniques, smaller, more linear incisions, and incisions that follow normal
tension lines in the skin to name only a few. However, these techniques have been mostly
limited to intraoperative or pre-operative measures. And while successful in minimizing scar
burden, these techniques do not address scar management post operatively.

Wound healing and scar formation follow complex biological processes dependent on
inflammatory cells and growth factors. It has been shown in utero that fetal wounds are
capable of scarless healing during a phase of gestation when wounds heal with a paucity of
inflammatory cells (Soo, Frantz). This principle was further studied in immune deficient
mice lacking both macrophages and neutrophils, which are critical to the inflammatory
response. Within this experiment, both groups of mice (immunodeficient and normal mice)
healed the wounds, the immunodeficient mice did so in a scarless manner (Mori, Martin).
Extrapolating this information to current surgical patients, the development of an
immunomodulating measure is critical to inhibiting and managing scar formation.

Adipose derived mesenchymal stem cells (ADSCs) have been studied with regard to their role
in the wound healing and scar formation process and have shown great promise. In
experimental studies, ADSCs have shown to promote angiogenesis, granulation and
reepithelialization of the overlying wound (Ebrahimian). Whether directly or indirectly
through these processes, the ADSCs also improve the appearance of resultant scars by
decreasing size, contrast of scar color, and improving pliability of the scar (Blanton,
Yun). However, it is not to be confused that all adipose tissue is equivalent with ADSCs.
Rather, ADSCs are a particular line of cells found within adipose tissue that have the
unique capability of differentiating into a variety of types of tissues, from bone to
cartilage to further adipose tissue (Zuk). These cells are capable of being harvested and
cultured from adipose tissue within subjects and then subsequently injected into the wound
site of interest.

Fat grafting is a similar but less involved technique that harvests autologous adipose
tissue but does not use cell culture techniques to isolate ADSCs from other cell lineages.
Fat grafting has long been used as a technique concurrently with facial reconstruction
procedures and facial rejuvenation procedures as a "filler" of sorts for facial augmentation
as early as 1893 (Miller). The fat injected into the face serves as a volume expander to
correct defects related to loss of muscle or bone, such as in micrognathia. Since those
initial trials, the technique has been widely expanded and honed to provide the best
possible contouring. In addition to the filler aspects and results of the procedure, the
technique has been observed to improve skin quality in injection sites, improve pigmentation
irregularities, and even improve appearance of long standing scars. However, a formal study
of fat grafting's potential of improved wound healing and minimization of scar formation has
never been undertaken.

Although not identical to the process of injection of autologous ADSCs, the process of fat
grafting has the capabilities of providing some number of ADSCs that were in the adipose
harvest. Additionally, the process itself has been shown in the past to improve previously
existing scars and improve the quality of skin overlying injection sites (Coleman).
Therefore, it is logical to assume that injection of autologous fat will improve wound
healing and minimize scar formation in patients undergoing the procedure through effects of
ADSCs within the harvested tissue.

With the advent of advanced 3-D imaging technology, we are now able to obtain high-quality,
high-resolution images to document and detail stages of wound healing and scar formation.
Therefore, we will be able to determine through observer analysis whether the process of fat
grafting changes the formation and quality of scars over time.

Inclusion Criteria:

- Healthy Subjects

- Facial reconstruction surgery in the last 3 months

Exclusion Criteria:

- Age less than 18 years

- Patients undergoing skin grafting

- Patients undergoing secondary intent closure