Adipocyte Damage in Relation to Different Pressures Generated during Manual Lipoaspiration with a Syringe

Abstract

Sir:FigureWe found the recently published work of Rodriguez and Condé-Green entitled “Quantification of Negative Pressures Generated by Syringes of Different Calibers Used for Liposuction” extremely interesting.1 Fat grafting has recently been experiencing an exponential growth of its surgical indications.2 However, it is commonly thought that, in contrast to liposuction with a cannula by a continuous vacuum system, harvesting through small syringes (e.g., 10-cc syringes) allows injury to be avoided and the viability of adipocytes to be preserved. These uninjured adipocytes can then be injected, after processing, into the recipient site, maximizing long-term surgical results. Rodriguez and Condé-Green demonstrated that negative pressure generated by a syringe is determined by the volume or number of cubic centimeters introduced in the syringe by pulling back the plunger. Another surprising observation is that syringe caliber should be considered a secondary factor. The pressure increase inside the syringe as the plunger is pulled back is not linear but parabolic, with rapid increases in negative pressure generated initially at low volumes and leveling off only after approximately 13 cc of plunger pull-back. Thus, the greatest increase in pressure is registered during one of the most commonly used harvesting methods, namely, harvesting with a 10-cc syringe. Rodriguez and Condé-Green use a graphic to help surgeons apply the desired negative pressure regardless of the syringe used, without quantifying the viability decrease in relation to the different pressures. Aiming to fill this gap, we compared the level of damage between samples of fat harvested with 5 (sample A) or 10 cc (sample B) of plunger pull-back in a 10-cc syringe and with 15 (sample C) and 30 cc (sample D) in a 30-cc syringe. The samples were collected manually, through a two-hole Coleman blunt microcannula attached to Luer-Lok syringes (Becton Dickinson, Franklin Lakes, N.J.), from the same donor site (thigh) performing a wet technique of harvesting. Adipose tissue samples were fixed in 4% formaldehyde in isotonic phosphate-buffered saline for 24 hours. Tissue sections of 5 mm were dehydrated in graded ethanol, cleared in xylene, pelleted by centrifugation at 100 g for 5 minutes, and embedded in paraffin. On a microphotograph (20×), with a corresponding field of 125,000 μm2, counting of adipocytes with cytoplasmic membrane rupture for field was performed. The counting was then repeated in 10 fields, obtaining a mean percentage range of nonviable adipocytes. Despite the operator-dependent detection method, the results (Table 1) validate the observations of Rodriguez and Condé-Green and demonstrate a dramatic percentage increase of nonviable adipocytes comparing the sample at 5 and 10 cc (Fig. 1), whereas the maximum value of membrane rupture (>75 percent) was recorded in sample D (30 cc of plunger pull-back).Table 1: ResultsFig. 1: Microphotographs (EE stain; original magnification, × 20) of 5 cc of plunger pull-back (sample A) (above), 10 cc of plunger pull-back (sample B) (center), and 30 cc of plunger pull-back (sample D) (below).Our observations confirm that extreme care must be taken during the harvesting phase to avoid affecting the results of the entire procedure. In addition, we finally recommend to never exceed 5 cc of plunger pull-back during manual fat harvesting to guarantee the success of this operative procedure. Damiano Tambasco, M.D. Department of Plastic and Reconstructive Surgery Vincenzo Arena, M.D. Department of Histopathology Francesca Grussu, M.D. Daniele Cervelli, M.D., Ph.D. Department of Plastic and Reconstructive Surgery, Catholic University of the Sacred Heart, Rome, Italy DISCLOSURE None of the authors has received any financial support or benefits pertaining to the study.