The Efficacy of Variable Intense-Pulsed Light (VPL) Treatment of
Striae Distensae: a new phototherapeutic approach
Neveerl F. M. Hassarz, M.D. *, Ahmud
N.Soleirnan, M.D. -/-
Ain-Shams University, Department of Dermatology*
King Fahd Hospital, Department of Pathology, KSAf
Background. Stretch marks or btriae distensae are cosmetically displeasing to many patients. Although
stretch marks are very common, satisfactory therapetitic intervention has been disappointing. Objective. To
assess gross and microscopical chi~ngcsthat occur in striae dis~ensaetreated with variable pulsed light
(VPL). Patients& Methods. The study included twenty patients with striae. Ten sessions of double-pass
VPL were performed in each of the patients once weekly. Ski11 biopsies, before and after treatment, were
taken. Data concerning the morphological featured included measuring of the length and width of each of the
treated striae. For statisti~alanalysis paired "I" test was used. Results. Patients showed clinical and
microscopical improvement. The "t" test showed statistically significant differences in the post treatment
length and width of treated striae (P<0.01). Microscopically, post-treatment epidzrinal and dermal thickness
demonstrated statistically signiiizan~ differences (P<0.05, P<0.01 respectively). Conclusion. Striae
distensae improved clinically and microscopically after VP12 treatment. It seems to be a promising
therapeutic option for this cornluoli problem.
Stretch marks or striae distensae are
cosmetically displeasirig to many patients.
Clinically, in early stages, stretch marks are flat
linear bands with a faint pink color, which
develop a violaceous hue as they enlarge both
in length and width (striae rubra). Over time,
these bands become increasingly atrophic,
depressed, and attain a white color. They are
referred to as mature striae (striae illha). Stretch
marks occur in areas of mechanical stress as
the abdomen, buttocks andlor the thighs. These
lesions are reported in multiple clinical settings
such as, adolescent growth spurts, pregnancy,
potent topical or systemic corticosteroid
therapy, obesity, and weight lifting (".
The precise etiology of striae is not well
understood. Part of the difficulty in
determining its etiology is the variability in the
clinical situations in which it arises.
Histopathological findings vary depending on
the age oi the lesions. Early leasions show
superficial and deep perivascular infiltrate of
lymphocytes and sometimes eosinophils, as
well as widely dilated venules and edema in the
upper part of the dermis. Elastolysis, mast cell
degranulation and activated macrophages have
also been described in early striae (2). Fully
developed lesions show scant infiltrate of
lylnphocytes around venules. Bundles of
collagen in the uppcr third of the reticular
dermis are thinned and aligned parallel to the
skin surface. Elastic fibers appear to be
increased in number and packed together as a
consequence of loss of collagen bundles. In
late stages, these findings are exaggerated with
a thin epidermis devoid of rete ridges. Loss of
clastic tissue accompanies loss of collagen;
resulting in a decrease in the thickness of the
dennis. Thcrefoi-e, it has been suggested that
the extracellular itlatrix, which provides
strength and resiliency, is altered or damaged
111 s ~ r i a c
"1.
Although stretch marks are very common,
satisfactory therapeutic intervention has been
disappointing. The treatment of striae distensae
or stl-etch marks has included Inany modalities,
with
variable success regarding their
therapeutic outcome (" 41. The use of topical
agents has been tried including tretinoin,
ascorbic acid, and glycolic acid. Topical
tretinoin 0.1% improved both the color and
lengthlwidth measurements in a controlled
study. However, qualitative and quantitative
analysis of elastic and collagen tissue staining
did not reveal significant differences between
tretinoin-treated and vehicle-treated groups 0).
In another study optical profilometry was used
to measure topographical changes in striae
after treatment with either 0.5% tretinoin
cream, 10% L-ascorbic acid, or 20% glycolic
acid. Unfortunately, improvement was only
reported in early striae and little or no effects
were seen in mature ones 14).
Later, treatment modalities were focused on
methods that remove the epidermis and cause a
dermal wound with subsequent dermal
collagen remodeling. These methods include,
besides chemical peels, dermabrasion, and
ablative lasers, including, pulsed C 0 2 and
Er:YAG lasers. Such methods commonly lead
to postoperative complications such as oozing,
bleeding, infections, and the occasional
incidence of undesirable postinflammatory
pigmentary changes (5-71.
Non-ablative laser therapy has recently
gained popularity as a therapeutic alternative
for stretch marks, as well as for other different
forms of scars (81. The flash lamp-pumped
pulsed dye laser (PDL; 585 nm) has been the
most commonly reported laser used for the
treatment of ~ t r i a e ( ~ . ' ~ ] .
Intense-pulsed light (IPL), is a noncoherent
filtered flashlamp with a very broadband
spectrum (515-1200 nm). It emits a visible
polychromatic pulsed light of high intensity.
Non-laser light can be delivered with a variety
of designated wavelengths. Filters are used to
include or exclude particular wavelengths. IPL
is used in photoepilation (I1], lentigens u2),
vascular malformations "3, poikiloderma of
Civatte (I4) and facial aging (15). The facial
photodamage
was
clinically
and
microscopically improved by IPL. When
higher filters are chosen shorter wavelengths
which may damage the epidermis without
adequate dermal penetration to promote
collagen remodeling are blocked. The longer
deeper
penetrating
wavelengths
are
non-specifically absorbed in the human dermis.
These wavelengths cause a non-specific dermal
wound, resulting in non-ablative dermal
remodeling with subsequent replacement of
elastosis by a more orderly neo-collagen (I2).
These results have prompted the trial of IPL in
the treatment of striae distensae. The newest
generation of IPL systems deliver the selected
wavelength in micro-pulses, that can be
adjusted regarding their duration and the delay
that that separate them one from the other (in
milliseconds ms.); hence, these systems deliver
Variable-Pulsed Light (VPL). Initial studies
[l6,I7)
suggest that VPL can substantially
improve facial rhytides by its presumed effects
on dermal collagen; however, no studies
evaluated its effects on stretch marks.
Aim of the study
To evaluate the efficacy of VPL treatment
of striae distensae. The study herein reports the
clinical and histologic results of nonablative,
variable-pulsed light treatment on striae
distensae.
PATIENTS & METHODS
Patients
Twenty patients (4 males and 16 females),
were included in the study.
Treatment striae were randomly selected from
every patient. Control (untreated) striae from
each patient were also selected for control.
Patients ranged in age between 18 and 45 years
of age (average of 28 years). The duration of
treated striae ranged between 6 months to 20
years (average of 9 years and 4 months). The
cause of striae in the study group varied from
fast growth in adolescent spurts (13 patients),
pregnancy (3 patients), weight training (3
patients), and weight loss (1 patient).
Treated striae were located on the
abdomenlgroin (9 patients), axillafanterior
shoulder (6 patients), and buttockslupper thighs
(5 patients). Nine of the treated striae were
pink to red in color, and eleven were white in
color. Every patient signed an informed
consent before starting treatment.
Exclusion Criteria:
Patients were excluded because of prior
treatment of striae six months before the study,
concomitant systemic steroids, Gushing's
disease, history of collagen or elastic tissue
Neveeo F. M. Hasw,~.M.D..
Ahmod N. Solei~~u,,,.M.D.
disorders, history of keloids, and lor female
patients known to be pregnant.
A total of sixty striae (three striae /patient)
have been selected for W L treatment. Their
lengths ranged between 17-35 cm (average 26
cm), and their widths ranged between 1-5 mm
(average 3mm). Clinical improvement of striae
was assessed, both by the patient and the
physician, immediately prior to each VPL
session, as well as, two weeks after the last
treatment. These data were classified in a scale
by crosses: 0 no improvement, + mild, + +
moderate, + + + good, + + + + very good.
Methods
The ENERGIST-Ultra, Energist Ltd, U.K.,
was adjusted to deliver pulsed light of 590 nm
wavelength through a standard spot size of
50x10 mm. All the patients were started on a
fluence of 30 JIcm2. This starting dose was
then increased by 20%irradiation dose
increments in subsequent sessions, according to
the tolerance of the patient, judged by the
absence of pain sensation; and the response of
the skin, noted by the absence of burning
erythema at the end of each treatment. The
Energist-Ultra represents the second generation
of pulsed-light treatment technology, which
delivers variable pulsed light (VPL). Each shot
of VPL comprises a sequence of four rapid
micro;pulses. These micro-pulses are of
variable durations (2, 2.5, 3 and 4 milliseconds
(ms), and are separated by a delay of 20 ms.
The operator and the patients' eyes were
protected by specific eye goggles provided
with the VPL-Ultra machine. The treatment
areas were painted with refrigerated cooling gel
(4"C), and the window was placed right on it.
The shots were made one after the other until
the whole area has been treated. A light redness
was considered as absolutely normal. In case of
strong redness, immediate application of
physiological saline together with fluence
reduction was carried out. Local anaesthesia, in
any form, was not used; as the subjective pain
sensation is a crucial monitoring sign during
irradiation fluence adjustment.
Ten sessions of double-pass VPL were
carried out for each patient, once a week.
Patients were photographed immediately
before the first session, and two weeks after the
tenth session. Two 4 mm punch biopsies were
taken, both of the same stretch mark, one
before treatment and one more two weeks after
the last session. The obtained biopsies were
stained by H&E. The degree of atrophy of the
epidermis was measured on a scale to indicate
if such finding was: 0 non-existent, + mild, + +
moderate, + + + or severe. The microscopic
findings considered in the dermis were: (a)
elastosis, (b) edema, (c) telangectasia, (d)
inflammation, and (e) quality of collagen
fibers. These findings were measured on the
following scale: 0 none, + mild, + + moderate,
and + + + severe. With respect to the collagen
fibers, their staining properties and fibrillar
nature were considered. Data were gathered by
reviewing 10 microscopical fields under 10 x
magnification, and then compared with data
reviewed frdm the second biopsy.
RESULTS
The results are divided into two sections:
clinical and histopathological assessments. The
ten sessions of VPL resulted in reductions in
the lengths and widths of treated striae in
comparison to the untreated ones in the same
patient (control).Two weeks following the
tenth VPL session, the mean length decreased
from 2633.25 cm to 16f0.9 cm. Applying the
"t" test for statistical analysis, the reduction
was found to be significant (pc O.Ol).Similarly,
post-treatment measurement of the mean of
the widest portion of the treated striae showed
significant reduction from 3M.93mm to
lk0.15mm (p<0.01). Comparison of the
clinical overall 'appearance of striae pre and
post treatment, as reported separately by the
patients and the treating physician, showed
post-treatment improvement, which was
moderate in eight patients (40%), good in four
patients (20%), and very good in eight patients
(40%) (Fig. 1)
-
Fig. 1. VPL-induced irnpmvement in the cchnical overall
appearance of striae distensae
J Egvpt wont Dermal01 Soc. Vol 3. No. 2,2006
7'heEjjiepcy uf Variable inre'nse -Pulsed Lizht (VPLJTrcutmenr
qfSrriae Disrcnrae: a n n v pthororherapeufic approach
Histopathologically, the epidermis showed
pretreatment atrophy in all cases. This atrophy
was considered severe in ten patients (50%),
moderate in six patients (30%), and mild in
four patients (20%). Post-treatment atrophy
changed to mild in 5 patients (25%), moderate
in 8 patients (40%), and only 3 patients (15%)
remained with severe atrophy. No atrophy was
noted in 4 patients (20%) (Fig. 2). The mean
epidermal
thickness
increased,
in
post-treatment assessment, from 0.17+0.03mm
to 0.5M.05 mm (p<0.05).
.- ..
w/o
perivascular inflammation was moderate in
60% of patients, mild in 20%, and absent in
20%.Two weeks after the last VPL session,
inflammation was moderate in 20% of patients,
mild in 50%. and absent in 30% (Fig. 4).
PW
VPL basbmnt
MIX
40%
Fig. 4. The percentage of privascular inflammation
before and after VPL treatment.
- .Pa
Post
WL basbnent
Pig. 2. Percentage of epidermal atrophy in striae
distensae before and after VPL treatment
The mean dermal thickness increased from
20.3mm to 3.3+0.4mm in pre- and
post-treatment measurements respectively (p
<0.01). As regards elastosis and edema,
pre-treatment evaluation showed severe degrees
in 60% of the patients, moderate in 20%, and
mild in 20%. Post- treatment assessment
revealed mild degrees in 60% of patients,
moderate in 20%, and severe in 20% (Fig. 3).
The collagen fibers revealed moderate
damage in 40% of patients and severe damage in
60% before treatment commencement.
Post-treatment, the damage was mild in 50% of
patients and moderate in the other 50%(Fig. 5,6)
None of the patients reported any of the
side-effects that they were told to observe
including, blistering, pain, longstanding
erythema, pigmentation and/or scarring.
mild
moderate
WL traahnant
Fig. 3. Percentage of dermal elastosis and oedema
before and after VPL treatment.
Telangiectasias did not show any change,
being severe in 40% of patients, moderate in
40%, and mild in 20% in both pre- and
post-treatment evaluations. Pre-treatment
I Eap worn Dern~urolSoc. Vol 3, No. 2, 2006
~ h dermis
i
shows ifiin,'fiint and fra@ented collagen
bundles (H&E, x4).
Nd: YAG and 1450-nm diode offered another
safe and effective noninvasive technique.
Modest long-term clinical improvement of
atrophic scars has been reported 124,251.
Lately. treatment of striae with IPL has been
suggested as a therapeutic modality that is
aimed at improving the appearance and
histology of stretch marks. The exact
mechanism of action of IPL in the treatment of
striae is unknown but effects on fibroblasts and
mast cells leading to collagen remodeling have
been speculated 1261. These speculations are
evidenced by the effectiveness of IPL in
photorejuvenation
ZRI, treatment of facial
rhytides '29', and poikiloderma of Civatte 130'.
In this study, all patients showed various
degrees of satisfactory chslnges regarding the
appearance of their treated striae. The
improvement was good and very good in most
of them. All clinical features assessed showed
significant improvement, including the lengths,
widths, as well as, the overall clinical
appearance of striae, in comparison to control
(untreated striae of the same patient).
Differences between the length and width of
pre and p~st-treatmentstriae were statistically
significant (p<0.01).
All parameters evaluated at microscopy,
except telangiectasia, showed variable but
satisfactory degrees of improvement. Despite
the fact that most of histologic findings are
subjectively evaluated, they still correlate with
the objectively assessed clinical signs of
improvement, including the pre and
post-treatment measurement of the lengths and
widths of striae. Furthermore, these
microscopic parameters provide the cellular
explanation for the clinical improvement
including, improvement in the epidermal
atrophy,
dermal
elastosis,
edema,
inflammation, and quality of the collagen
fibers. The lack of improvement regarding
telangiectasia could be caused by that the
wavelength used in this study (590 nm) differs
from that needed to achieve a satisfactory
effect on dilated blood vessels (550-570
nm).The epidermal thickness was increased on
average from 0.17 to 0.5 mm. Such difference
was considered statistically significant (p
4.05). The dermal thickness showed the most
important improvement at the end of treatment
'".
Rig. 6. Post-treatment h~opsy snowlng tncreaseo
epidermal thickness. The dermis shows thickened
collagen bundles (H&E, x4).
DISCUSSION
Striae distensae remain a frequently
encountered, difficult to-treat cosmetic
problem. Topical therapies yield variable
therapeutic results, and surgical options carry
an increased risk for further scar development
I3s4). Non-ablative laser treatment represents the
newest approach to initiate and enhance dennal
collagen remodeling. After laser irradiation of
the skin, thermal injury is localized to the
papillary and upper reticular dermis, while the
epidermis is concomitantly protected by
surface cooling. Various non-ablative laser
systems proved to improve different clinical
situations characterized by atrophy and1 or
scarring. Induction of dermal collagen without
epidermal damage was fist demonstrated using
a 585-nm flashlamp-pumped pulsed dye laser
(PDL) for hypertrophic scars f18. 19), and in the
treatment of facial rhytides (9+2". Regarding the
therapeutic outcome of PDL in striae distensae,
reports were conflicting. Some studies
211
reported improvements of this cosmetic
problem whether in the clinical appearance
and/ or the histologic findings. Whereas, others
1'2.23) found no differences in the condition after
PDL treatment. Subsequently, the 1320-nm
Tile Eflcacy 1fVurta6lr i~tmlre
cfStn',~lrDivrfunrae: a newg
(p<O.01). The increase in dermal thickness can
be clearly attributed to the increase in collagen
fibers, as the post-treatment collagen acquired
a more fibrillar aspect and took up more pink
stain.
In none of the patients studied were neither
"no improvement" nor adverse reactions that
lead to inconvenience, lack of compliance andl
or discontinuation of treatment.
In conclusion, VPL is a low-risk,
well-tolerated procedure that can potentially
affect collagen remodeling. It seems to be a
promising alternative for treatment of striae
distensae. The satisfactory clinical and
histologic outcome data point out that the
non-ablative Variable Pulsed Light technology
is an option to be considered in this frequently
encountered cosmetic problem.
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