Examining Preparation Systems for Autologous Fat Grafting

A randomized prospective study (NCT02677012), published in Plastic and Reconstructive Surgery, recently investigated 3 frequently used systems for graft preparations to compared the rate of graft processing.¹

Autologous fat grafting is a procedure that takes adipose tissue from one part of the body, processes or purifies the tissue and then delivers it to a different location. This has most often been used for creating more volume. The 3 main stages of an autologous grafting procedure—harvest, processing, and delivery—can affect many factors such as clinical outcomes, operative efficiency, and cost.

The study focused on 3 methods of preparing adipose tissue for grafting: an active filtration system (Revolve; LifeCell Corporation), a passive filtration system (PureGraft 250; Cytori Therapeutics), and centrifugation.1 Currently, there is no consensus on which technique is superior to another. 

The primary outcome, according to study investigators, was the rate at which adipose tissue was processed. Patients were excluded if they were 18 years or younger, unable to give consent, actively undergoing cancer treatment—not including hormonal therapy—were pregnant, had a body mass index (BMI) of less than 18, or could not achieve minimum volume of lipoaspirate (100 ml). 

The 46 eligible patients were randomized into 3 arms at a 1:1:1 ratio: the active filtration arm, passive filtration arm, and centrifugation arm. They were also stratified by a surgeon, guaranteeing that each surgeon would contribute to the same number of cases per technique. The following patient information was collected: age, BMI, prior surgical history, prior chemotherapy, and prior radiation therapy. 

The mean patient age and BMI was 54 years old with a BMI of 28.6 kg/m2. More than 75% of patients were nonsmokers and had no active medical comorbidities. In total, there were 8 cases that exclusively had autologous fat grafting. This means 83% of operative cases had additional procedures. These procedures included implant exchange, mastopexy, scar revision, and other non-specified operations. Additionally, there were no statistical differences between the 3 cohorts in patient demographics or reconstruction characteristics.

There was a significantly faster rate of adipose tissue processing for the active filtration system compared with the other systems: active filtration: 9.98 ml/min vs passive filtration: 5.66 ml/min vs centrifugation: 2.47 ml/min. There was a significant difference in total grafting time for the active arm (82.7 minutes) compared to passive arm (152 minutes), and centrifugation arm (209.9 ± 28.5 minutes). However, there was no difference in total operative time (active filtration: 168 minutes, passive filtration:157 minutes, centrifugation: 187 minutes). 

There was more lipoaspirate harvest and process in the passive filtration procedures, but overall volume was determined by surgeon need and patient factors. There was also a higher percentage of fast available resulting from active filtration compared to passive filtration or centrifugation. Still, the mean labor time was similar amongst all 3 cohorts.

As the popularity of fat grafting procedures increase, according to investigators, more scrutiny is needed when developing techniques to harvest, process, and inject fat to improve clinical outcomes and operative efficiency. 

Reference:

1. Hanson SE, Garvey PB, Chang EI, et al. A randomized prospective time and motion comparison of techniques to process autologous fat grafts. Plastic & Reconstructive Surgery. 2021;147(5):1035-1044.