Use of Condensed Nanofat Combined With Fat Grafts to Treat Atrophic Scars

Abstract

Importance: In addition to the physical deformity, there is often great psychological burden of facial scars for patients. In this study, we use condensed nanofat combined with fat grafts in a novel technique to improve atrophic facial scars by raising both the surface and the bottom of the affected area.

Objective: To assess whether the use of condensed nanofat combined with fat grafting can be effective in treating atrophic facial scars from both an aesthetic and a functional perspective.

Design, setting, and participants: In this prospective case series of 20 patients with 25 atrophic facial scars, each scar was treated with condensed nanofat combined with fat grafts at the Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, Zhejiang, China. Postoperative results were evaluated by the patients themselves and by 3 senior plastic surgeon observers.

Main outcomes and measures: Multiple preoperative and postoperative examinations included the use of the Patient and Observer Scar Assessment Scale (POSAS) to evaluate both the functional and aesthetic aspects of the atrophic facial scars. Punch biopsy specimens were stained for the presence of melanin, elastic fibers, and cytokeratin (CK) 14 and CK19. Images were analyzed using ImageJ software, and the data were analyzed by paired sample t test.

Results: Twenty patients (6 men and 14 women; mean age, 38.25 years; age range, 21-62 years) with a total of 25 atrophic facial scars were treated between March 2014 and December 2016. The patients' mean (SD) scar assessment scores were significantly decreased postoperatively in the final examination for color, 6.40 (0.51) vs 2.40 (0.24) (P < .001); stiffness, 7.20 (0.37) vs 3.20 (0.20) (P < .001); thickness, 5.80 (0.73) vs 1.80 (0.37) (P = .001); and irregularity, 5.20 (0.49) vs 2.20 (0.37) (P = .003); and the observers' scores were also significantly decreased for pigmentation, 4.40 (0.51) vs 2.00 (0.32) (P = .004); thickness, 3.00 (0.32) vs 1.80 (0.20) (P = .03); relief, 4.40 (0.51) vs 2.40 (0.24) (P = .003); and pliability, 4.20 (0.37) vs 1.40 (0.24) (P < .001). In the final follow-up examinations, a significantly improved overall POSAS score was found among both patients, 28.80 (1.02) vs 12.20 (0.80) (P < .001), and observers, 18.00 (0.71) vs 9.20 (0.37) (P = .001). Enhancement of Fontana-Masson staining of melanin in the basal cell layer was observed postoperatively, and a significant postoperative change was detected for the mean (SD) values of average optical density from the preoperative measurement, 0.671 (0.083) vs 0.844 (0.110) (P = .01). The sebaceous glands and sweat glands that were not found in the preoperative images were seen postoperatively by immunohistochemical staining with CK14 and CK19.

Conclusions and relevance: Our preliminary clinical and pathological results indicate that the use of condensed nanofat combined with fat grafts may be an effective approach to treating atrophic facial scars from both an aesthetic and a functional perspective.

Level of evidence: 4.

Figure 1.. Clinical View of 2 Types of Atrophic Scars

A and B, Case 1 shows an irregular and patchy scar on the right cheek preoperatively (A) and 6 months postoperatively (B). Case 2 shows a linear atrophic scar (arrowhead) on the forehead preoperatively (C) and 14 months postoperatively (D).

Figure 2.. Illustrated Differences Between the Traditional Fat Graft and the Technique Using Condensed Nanofat Combined With Fat Graft

A, The commonly used autologous fat grafting procedure is achieved through subcutaneous injection, but the cannula is not thin enough to inject fat grafts into a scar to elevate the surface of the scar. B, For the nanofat technique in linear scars, the condensed nanofat is injected into the scar with 29-gauge insulin syringes to elevate the surface. C, For the nanofat combination technique in irregular and patchy scars, the fat graft is injected into the tissue under the scar, and the condensed nanofat is injected into the scar to elevate both the surface and the bottom of scar.

Figure 3.. Patient and Observer Scar Assessment Scale Scores

Figure 4.. Histopathologic Findings for Melanin and Sebaceous and Sweat Glands

A and B, Under Fontana-Masson staining, an increase in melanin is seen in the basal cell layer between the preoperative (A) and 6-month postoperative (B) specimens (original magnification ×400). C and D, Under cytokeratin (CK) 14 staining, almost no sebaceous or sweat glands were observed preoperatively (C), but they were clearly visualized 6 months postoperatively (D) (original magnification ×200). E and F, Under CK19 staining, almost no sebaceous or sweat glands were observed preoperatively (E), but they were clearly visualized 6 months postoperatively (F) (original magnification ×100).