Joris van Dongen

36 Chapter 2 Characteristics of the intraoperative isolation procedures All intraoperative isolation procedures are divided into two categories: enzymatic and non-enzymatic procedures resulting in cSVF and tSVF respectively (Table 4A and table 4B). Eight of the eighteen intraoperative isolation procedures were based on enzymatic digestion and ten isolation procedures were based on non-enzymatic procedures. Two non-enzymatic procedures, the Residual tissue of emulsified fat procedure and the Fractionation of adipose tissue procedure, are named differently, but are almost identical. One intraoperative isolation procedure, the Filtrated fluid of emulsified fat, is a combined procedure of two other intraoperative isolation procedures i.e. the Fractionation of adipose tissue procedure and the Nanofat procedure 66-68 . Start volume versus end product The Automated isolation system, GID SVF2, Lipokit system and Multi station are enzymatic intraoperative isolation procedure that resulted in large average amounts of SVF (7.2 ml – 20 ml), suggesting inefficient enzymatic digestions 69,70 . The non- enzymatic intraoperative isolation procedures resulted in larger end volumes than only a pellet. Prior the Lipogems procedure, 130 ml of adipose tissue can be obtained to mechanical dissociate to 100 ml of lipoaspirate. Hence, this a reduction of the volume of 1.3 times, suggesting an inefficient mechanical dissociation to our opinion 22 . In contrast, the Fractionation of adipose tissue procedure resulted in a 10.4-fold volume reduction 67 . For all other intraoperative isolation procedures, no data is mentioned about the end volume of the lipoaspirate (Table 4A and table 4B). Duration and costs Duration of the intraoperative isolation procedures varied from 5 seconds to 133 minutes (n=12). Isolation with the Automated isolation system was the longest intraoperative isolation procedure 69 . Shuffling lipoaspirate 5 or 30 times through a luer-to-luer lock syringe will take 5 or 30 seconds respectively and were therefore the fastest procedures 71 . In general, the tested non-enzymatic procedures take less time than the enzymatic procedures (Table 4A and table 4B). The costs of only enzymatic procedures Celution system (2013: $1950 and 2016: $2400), CHA-station ($710), Multi station (2013: $460 and 2016: $250), Lipokit system (2013: $530 and 2016: $450) and GID SVF2 ($1000) are mentioned, the enzymatic Celution system being the most expensive 70,72 . No data of non-enzymatic intraoperative procedures were available (Table 4A and table 4B).