Evolution of the Push-2-Spin Fat Graft Processing Device: Enhancing Efficiency and Reducing Risk of Contamination

Abstract

Background: Small-volume fat graft efficiency is a critical determinant of the cost and material effectiveness of aesthetic fat grafting in the clinical space. Recent development of devices, such as the Push-2-Spin (P2S) system (Pittsburgh, PA), has improved upon the process by yielding a rapid, handheld, multi-use system to minimize operative time and mess.

Objectives: In this study, the authors describe further technical innovations on the P2S prototype that improve operative ease of use, time, and safety.

Methods: Abdominoplasty samples were obtained as discarded tissue. Lipoaspirate was collected utilizing a 3.0 mm liposuction cannula and processed through centrifugation (Coleman technique), gauze (telfa) rolling, mesh straining, the tabletop P2S device (prototype), or the P2S handheld (P2S-H) device. Operative processing time, spin time, oil fraction, stromal vascular fraction (SVF) yield and viability, and adipocyte viability were assessed to compare the efficacy and viability of each device/technique. Blood agar smears of lipoaspirate were performed to assess for risk of contamination.

Results: The P2S-H device outperformed its prior iteration in rotary and processing speed and was significantly faster than each other technique assessed. Furthermore, the use of an inline system offered significant advantages over open-air techniques in terms of resistance to contamination. Serial use characteristics were assessed; under these conditions, oil yield as well as adipocyte and SVF number and viability was similar between all techniques.

Conclusions: The technical advancements to the P2S system which enable single-unit, handheld operation significantly improve operative time and minimize space requirements. This operative quality of life improvement comes at no cost to the efficacy of oil extraction, cellular yield, or cell viability.

Figure 1.

(A) Schematic representation of the Push-2-Spin handheld (P2S-H) device with comparison to the original benchtop system. (B) Total spin time is significantly decreased with the P2S-H vs the prototype. (C) Time to spin is decreased in the P2S-H vs prototype. (D) The P2S-H significantly improves spin time vs both the P2S prototype and all other techniques tested. (E) There is a significant improvement in processing time per cc of lipoaspirate in the 20 vs 10 cc version of the P2S-H system. All error bars represent SD. †Significant difference among all the other represented groups. *P < .05. For all timed trials, n = 10.

Figure 2.

(A) Oil column schematic. (B) Oil is significantly purified with all techniques/devices tested vs unspun control lipoaspirate. (C) Purification increases with an increasing number of consecutive spins. (D) Representative oil columns of the effect of consecutive spins. (E) No significant difference was noted in the oil fraction between samples collected from 10 and 20 cc devices. (F) Purification decreases with an increasing number of sequential purification. (G) Representative oil columns of the effect of sequential purification of the Push-2-Spin handheld (P2S-H) system. All error bars represent SD. *P < .05. †Significant difference among all other represented groups. ^#Both first and second processing runs are significantly different when compared with both the third and fourth processing runs. For all adipose/oil columns assessed, n = 5.

Figure 3.

Representative image of blood agar plates inoculated after (A) traditional or (B) Push-2-Spin (P2S) techniques for adipose processing under laminar air-flow conditions (left) or under open-air sterile field (right). (C) Quantification of colony-forming units (CFUs) (arrows) from high-powered fields (HPFs) of blood agar plates inoculated after the conditions described for A or B. (D) Quantification of CFUs from HPFs of blood agar plates inoculated after either first pass or subsequent fat processing using the P2S device. All error bars represent SD. *P < .05. For all conditions assessed, n = 20 HPFs.

Figure 4.

There is no significant difference in stromal vascular fraction (SVF) density (A) between any of the techniques tested (n = 5) or (B) between the 10 and 20 cc devices tested. There is no significant difference in SVF viability (C) between any of the techniques tested or (D) between the 10 and 20 cc devices tested. There is no significant difference in mature adipocyte viability (E) between any of the techniques tested or (F) between the 10 and 20 cc devices tested. (G) Representative images of mature adipocytes collected after either Coleman centrifugation or spinning using the 2 Push-2-Spin devices tested (Protoype and P2S-H). Viability was assessed by Calcein-AM (middle column); cell death was assessed by propridium iodide exclusion (right column). Images were obtained from an automated Cellometer readout utilizing onboard software. All images within a row represent the same high-powered field and scales are equal for all rows. All error bars represent SD. *P < .05. For comparisons between groups, n = 5.