The role of the ultrasound facelift procedures number in SMAS flap histological structure in the long term

Objective. To identify the relationship between the histological structure of the SMAS flap and the number of ultrasound facelift procedures.
Patient and Methods. The study included 129 patients aged 35 to 55 years who had undergone SMAS facelift of the lateral face. The first group included 30 women aged 35 to 51 years. These patients had not undergone ultrasound facelift. The second group included 33 women aged 38 to 55 years who had undergone a single ultrasound facelift before SMAS facelift of the lateral face. The third group included 31 women (aged 36-49 years). These patients underwent two ultrasound facelift procedures before surgery. The fourth group consisted of 35 women aged 41 to 54 years who had undergone three preoperative ultrasound facelifts. All patients underwent intraoperative SMAS flap biopsies. The obtained tissue sections were stained using Verhoef-van Gieson, Mallory, and Masson trichrome staining methods. A qualitative analysis of the sections was performed for the presence of collagen and elastic fibers, adipose tissue, striated muscle, and vessels in the SMAS flap sections. Results. In patients who had not undergone ultrasound-assisted facelift, the SMAS flap consisted almost entirely of adipose tissue with thin layers of connective tissue septa containing vessels. In the group of patients who had undergone a single ultrasound-assisted facelift procedure, the SMAS flap was composed of equal parts of both adipose and connective tissue. After two ultrasound-assisted facelift procedures, histological analysis of the intraoperative biopsies showed that the SMAS flaps in these cases contained 70 to 80% connective tissue, with the remainder consisting of adipose tissue, including vessels. After three ultrasound-assisted facelifts, the SMAS flaps were thin and fairly rigid when stretched. Histological analysis revealed that biopsy sections from these flaps consisted primarily of connective tissue and contained 10 to 15% adipose tissue. After two or more ultrasound-assisted facelifts in groups 3 and 4, the connective tissue in the SMAS flap consisted only of collagen fibers and fibroblast and fibrocyte nuclei.
Conclusion: A single ultrasound-assisted facelift results in a significant reduction in the elastin fiber content of the SMAS flap at various times post-procedure. Double and triple ultrasound facelifts of the SMAS flap destroy the elastic fibers in the flap area, and the flap connective tissue contains only collagen fibers.
Keywords: SMAS flap, ultrasound facelift
Conflict of interest. The authors declare no conflict of interest.
Financing. The work was completed without sponsorship