Biomedical Engineering Reference
In-Depth Information
intracellular lipid contents, and how this is metabolized by the
body is unclear. Studies on lipid levels following LAL indicate
no change in serum lipid levels following the procedure
(11,34). Mordon et al. followed serial lipid panels in four
patients for 30 days following LAL and found no deviation
from baseline levels (34). Goldman and coworkers conducted
LAL with a 1064-nm device and observed no increase in cho-
lesterol or triglyceride levels following the procedure (11).
Woodhall et al. also found no change in triglycerides in 39
patients undergoing LAL with the 1064 nm, 1320 nm, or mul-
tiplex (1064 + 1320 nm) device (28). Given the lack of serum
lipid level elevation following LAL, there appears to be no
lipid-related renal or hepatotoxicity risk. Lipid metabolism
following LAL has not been studied although mechanisms of
action have been postulated. Lipid metabolism may occur
slowly, avoiding changes in serum lipid levels or alternatively,
lipids may be cleared through a phagocytic route via macro-
phage digestion (34).
study by Elm and colleagues evaluated the effi cacy of LLLT
(Zerona System
TM
, Santa Barbara Medical Innovations, Dallas,
Texas, USA) for body contouring, independent of body suc-
tion (52). Five patients received six treatments over a 2-week
period on one side of the body and were evaluated by three
blinded dermatologists 7 days and 1 month after last treat-
ment. The authors found that circumference measurements
revealed no statistically signifi cant reduction in fat layer thick-
ness, a fi nding confi rmed also by ultrasound evaluation. Eval-
uation by three blinded dermatologists resulted in average
correct photo identifi cation of 51.1%, refl ecting little clinical
difference between posttreatment and baseline images. There-
fore, the authors conclude that more studies are required to
show clinical improvement in body contouring before LLLT
can be recommended.
A second noninvasive laser light source has been used to tar-
get adipocytes. Wanner et al. used a 1210-nm, CW semicon-
ductor diode laser to treat 24 patients (53). A 3-second
exposure with precooling was used at increasing fl uences to
treat the abdominal area. The treatment was painful, necessi-
tating the use of local anesthesia. Erythema persisted after
treatment in some cases for several days. Histologic evidence
of fat necrosis was noted, but dermal damage was also present
with increasing energy. The authors concluded that this laser
light source may preferentially target adipocytes but within a
narrow therapeutic window. Further refi nement in pain man-
agement, epidermal cooling, and energy delivery is necessary
before this laser light source is a safe and reliable device for
targeting fat.
noninvasive laser lipolysis technology
Several technologies have appeared in the medical literature as
possible noninvasive laser alternatives for adipocyte destruc-
tion. The advantage of such technology, if effective, would be
the nonsurgical delivery of therapy. However, the relative pau-
city of available studies as well as the lack of reproducibility
from one of the studies casts doubts on the true effects and
effi cacy of these light sources.
The fi rst noninvasive laser light source reported to produce
fat liquefaction was a 635-nm, low-level energy laser source
(49). Low-level laser therapy (LLLT) requires that the delivery
of laser energy does not result in a temperature increase in the
treated tissue. A similar light source has been used in a variety
of applications in the fi elds of physical therapy and anti-
infl ammatory research (50) and is FDA approved for pain alle-
viation and for use with lipoplasty (51). Other applications
include promotion of wound healing and edema reduction
(49). The clinical effects may be partially explained by the
multitude of effects on the skin from the action spectra pro-
duced within the wavelengths of 630-640 nm. These include
fi broblast and keratinocyte proliferation, microcirculatory
stimulation, and scar diminution (49).
In an effort to exploit the biomodulatory effects of low-level
635-nm laser light (Erchonia Laser PL3000™, Majes-Tec Inno-
vations, Inc., Mesa, Arizona, USA), Neira and coworkers sub-
jected 12 human post-lipectomy adipose tissue samples to
treatment for increasing time periods (49). The device consists
of a single diode, variable hertz, red light source. Neira et al.
reported 80% adipocyte membrane disruption after 4 minutes
of exposure to laser light and 99% disruption after 6 minutes.
An electron microscopic examination revealed transitory
pores within cell membranes, defl ation of adipocytes, and
emptying of cellular contents (49).
The favorable results reported by Neira et al. in 2002 failed
to be reproduced by an independent study in 2004 by Brown
and coworkers (51). Using both porcine and human models,
no cellular changes were observed following low-level 635-nm
laser treatment. Despite lengthy exposure times of up to 60
minutes, no change in adipocyte structure or morphology was
demonstrated, casting doubt in the belief that this diode laser
source produces adipocyte liquefaction (51). In addition, a
developments and future applications
Appropriate uses for LAL will continue to develop as this tech-
nology matures. It has been suggested that LAL may be a suit-
able treatment for axillary hyperhidrosis (15), for revising
fl aps (14), facial sculpting, and periorbital adipose tissue and
skin tightening (42). A study utilized LAL with a 980-nm diode
device to successfully treat a series of 28 male patients with
gynecomastia (54). Twenty-two patients (78.6%) had very
good results, and no complications were reported.
There is a particular interest in utilizing LAL for the treat-
ment of cellulite, a condition that affects approximately 85%
of postpubertal women (55). Cellulite continues to be a frus-
trating esthetic problem for many women without treatment
modalities that offer dramatic improvement. In fact, tradi-
tional liposuction affords only minimal improvement of cel-
lulite and may even worsen its appearance (30).
Combination treatment of LAL with autologous fat transfer
was used in a small case series of 52 female patients (30). A
1064-nm Nd:YAG system (SmartLipo) was combined with
subsequent fat transfer to treat Curri grades III-IV cellulite of
the hips, buttocks, thighs, and abdomen. Patients were very
pleased with the clinical outcome, with 84.6% of patients rat-
ing their results as good to excellent, but the effect of the laser
alone was unknown (30).
We conducted our own study to answer this question. Nine
patients and 11 sites were treated in a comparative study of
LAL (CoolLipo) to mechanical disruption with a liposuction
microcannula (Palm, Goldman, presented at the ASDS
National Meeting, Oct 4, 2009, Phoenix, Arizona, USA). There
was no difference between treatment groups in regard to
