Adhesion formation contributes to
postoperative complications in abdominal and gynaecological surgery.
Thus far, the prevention and treatment strategies have focused on
mechanical barriers in solid and liquid form, but these methods are not
in routine use. As autologous fat grafting has become popular in
treatment of hypertrophic scars because of its immunomodulatory effects,
we postulated that fat grafting could also prevent peritoneal adhesion
through similar mechanisms.

This was a control
versus intervention study to evaluate the effect of fat grafting in the
prevention on peritoneal adhesion formation. An experimental mouse model
for moderate and extensive peritoneal adhesions was used (n = 4-6
mice/group). Adhesions were induced mechanically, and a free epididymal
fat graft from wild type or CAG-DsRed mice was injected preperitoneally
immediately after adhesion induction. PET/CT imaging and scaling of the
adhesions were performed, and samples were taken for further analysis at
7 and 30 days postoperation. Macrophage phenotyping was further
performed from peritoneal lavage samples, and the expression of
inflammatory cytokines and mesothelial layer recovery were analysed from
peritoneal tissue samples.

Fat grafting
significantly inhibited the formation of adhesions. PET/CT results did
not show prolonged inflammation in any of the groups. While the
expression of anti-inflammatory and anti-fibrotic IL-10 was
significantly increased in the peritoneum of the fat graft-treated group
at 7 days, tissue-resident and repairing M2 macrophages could no longer
be detected in the fat graft at this time point. The percentage of the
continuous, healed peritoneum as shown by Keratin 8 staining was greater
in the fat graft-treated group after 7 days.

Fat
grafting can inhibit the formation of peritoneal adhesions in mice. Our
results suggest that fat grafting promotes the peritoneal healing
process in a paracrine manner thereby enabling rapid regeneration of the
peritoneal mesothelial cell layer.