209The harvesting cannula is inserted through the puncture wound into the subcuta-
neous adipose layer of the abdominal donor site (Fig. 10.2 ). The plunger of the
syringe is withdrawn 1–3 ml at a time to create the low negative pressure vacuum
within the barrel of the harvesting cannula and syringe. The surgeon holds the har-
vesting cannula attached to the syringe in his dominant hand while gently grasping
the skin of the abdominal area with his nondominant hand in order to lift the subcu-
tis from the underlying structures. The fat is aspirated using a meticulous, atrau-
matic technique by smoothly advancing and retracting the harvesting cannula
through the subcutaneous adipose layer. This movement is done very quickly and
forcefully through the donor area, in order to avoid blood contamination of the col-
lected adipose tissue sample. The harvesting cannula is repeatedly advanced in a
transverse direction while slowly progressing in a circular pattern until the needle
points in an inferior direction from the puncture wound. This directional movement
in the liposuction technique is called the fan formation. The harvesting fan forma-
tion is repeated on the opposite side. This fan formation of fat aspiration is used to
avoid blood contamination of the sample during the harvesting process.
As the syringe fi lls with lipoaspirate, the negative pressure decreases until the
suction vacuum is insuffi cient to allow for further harvesting of adipose tissue
(Fig. 10.3 ). The harvesting cannula is then extracted from the puncture wound and
removed from the patient. The plunger is withdrawn from the syringe and the aspi-
rate is decanted into a sterile bottle (Fig. 10.4 ). The sterile bottle contains
phosphate- buffered solution at a pH of 7.4 (PBS) as well as 5 % penicillin and
streptomycin (pen/strep). The harvesting process is repeated until a reasonable
amount of virgin fat has been collected. The process is terminated when excessive
Fig. 10.1 Harvesting
cannula with a blunt tip in
the shape of a bucket
handle. The Coleman
harvesting cannula
dimensions are 150 mm in
length, 4 mm external
diameter, and 2.5 mm
internal diameter. The
proximal end of the
harvesting cannula is
shaped to fi t securely into a
10 ml Luer Lock syringe
10 Harvesting and Collection of Adipose Tissue for the Isolation...