A comparative study evaluating the clinical efficacy of skin tapes versus silicone gel for the treatment of posttrauma scar in the rabbit model

Abstract

Background: Skin tape and silicone gel are two common over-the-counter preparations used to enhance the cosmesis of keloids and hypertrophic scars of posttrauma wounds. This animal study was performed to determine the clinical efficacy of skin tape versus silicone gel in subjects with scars. Materials and Methods: Three New Zealand rabbits that received total 12 incision wounds which two incision wounds on one ear side and subsequent primary suturing were studied. Stitches were removed after 1 week. Silicone gel was applied right upper side of the rabbit’s ear directly on surgical incision wounds, and skin tapes were also applied left upper side of the rabbit’s ear directly on another surgical incision wounds after 1 week of surgery. The lower incisions in both ears were covered with sterilized gauze and served as controls. We compared two experimental groups at binaural with using Vancouver Scar Scale, Manchester Scar Scale, and The Stony Brook Scar Evaluation Scale. These are widely used in clinical practice and research to document change in scar appearance. Results: We describe a rabbit model for incisional wounds and scarring outcome measures. The results of scar measuring devices demonstrated that skin tape reduced scar formation as well as silicone gel. Conclusions: The results of cosmetic demonstrated that skin tape reduced scar formation as well as silicone gel. However, the economical and effective materials were the important subject that suffices for clinical requirement. The application of these scar prevention devices to reduce scar formation after surgical incision is worthy of future investigation. Moreover, skin tape may represent a low-cost alternative and low scar formation for closure of surgical incisions.

Full text

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Background: Skin tape and silicone gel are two common over-the-counter preparations used to enhance the cosmesis of keloids
and hypertrophic scars of posttrauma wounds. This animal study was performed to determine the clinical efcacy of skin tape
versus silicone gel in subjects with scars. Materials and Methods: Three New Zealand rabbits that received total 12 incision
wounds which two incision wounds on one ear side and subsequent primary suturing were studied. Stitches were removed
after 1 week. Silicone gel was applied right upper side of the rabbit’s ear directly on surgical incision wounds, and skin tapes
were also applied left upper side of the rabbit’s ear directly on another surgical incision wounds after 1 week of surgery. The
lower incisions in both ears were covered with sterilized gauze and served as controls. We compared two experimental groups
at binaural with using Vancouver Scar Scale, Manchester Scar Scale, and The Stony Brook Scar Evaluation Scale. These are
widely used in clinical practice and research to document change in scar appearance. Results: We describe a rabbit model for
incisional wounds and scarring outcome measures. The results of scar measuring devices demonstrated that skin tape reduced
scar formation as well as silicone gel. Conclusions: The results of cosmetic demonstrated that skin tape reduced scar formation
as well as silicone gel. However, the economical and effective materials were the important subject that sufces for clinical
requirement. The application of these scar prevention devices to reduce scar formation after surgical incision is worthy of future
investigation. Moreover, skin tape may represent a low-cost alternative and low scar formation for closure of surgical incisions.
Key words: Skin tape, silicone gel, scar formation
Received: January 6, 2014; Revised: August 26, 2014;
Accepted: August 28, 2014
Corresponding Author: Dr. Chih-Hsin Wang,
Department of Surgery, Division of Plastic Surgery,
Tri-Service General Hospital and Graduate Institute of
Medical Sciences, National Defense Medical Center,
Taiwan, Republic of China. No. 325, Sec. 2, Cheng-
Gong Road, Taipei 114, Taiwan, Republic of China.
Tel: +886-2-87927195; Fax: +886-2-87927194.
E-mail: tsghcc@gmail.com
INTRODUCTION
Scars are represented an abnormal and exaggerated healing
response after skin injury. In addition to aesthetic concerns, scars
may cause pain, pruritus, contractures, and other functional
impairments.1 Therapeutic modalities for the management of
scars include topical medications, intralesional corticosteroids,
laser therapy, and cryosurgery. Topical therapies, in particular,
have become increasingly popular due to their ease of use,
comfort, noninvasiveness, and relatively low cost. Studies
A Comparative Study Evaluating the Clinical Efcacy of Skin Tapes versus
Silicone Gel for the Treatment of Posttrauma Scar in the Rabbit Model
Chih-Chien Wang1,5, Juin-Hong Cherng2, Shyi-Gen Chen3, Tsai-Wang Huang4,5, Leou-Chyr Lin1, Ru-Yu Pan1,
Yi-Hsin Chan5, Chih-Hsin Wang3,5
1Department of Orthopedic Surgery, 3Department of Surgery, Division of Plastic Surgery, 4Department of Surgery,
Division of Thoracic Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, 2School of Dentistry,
5Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China
have examined the properties and effectiveness of these agents
including pressure therapy, silicone gel sheeting and ointment,
polyurethane dressing, onion extract, imiquimod 5% cream,
and vitamins A and E for the prevention and treatment of
hypertrophic scars.2 The use of skin tape to treat scarring
is still relatively new, and it was introduced in 1981 for the
treatment of burn scars. Consequently, the study has indicated
that hypertrophic and stretched scars formed during the skin
tape were removed; it has suggested that tension acting on a
scar is the trigger for hypertrophic scarring. Skin tape could
be an effective modality for the prevention of hypertrophic
scarring through its ability to eliminate scar tension.3,4
The hypothesis is that mechanical forces might stimulate
epidermal cells proliferation and vascular remodeling in
living skin. As epidermal cells growth and vascular supply
are critical to wound healing and tissue expansion, applying
devices with controlled mechanical loads to tissues may be a
powerful therapy to treat tissue defects.5 However, using skin
tape to support the scar may reduce multidirectional forces
and prevent hypertrophic scarring.6 In addition, silicone has
been proposed as the main form of noninvasive treatment for
ORIGINAL ARTICLE
J Med Sci 2014;34(5):195-200
DOI: 10.4103/1011-4564.143641
Copyright © 2014 JMS
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Skin tapes versus silicone gel for posttrauma scar
196
hypertrophic and keloid scars and has demonstrated signicant
improvements in scar elasticity in patients prone to abnormal
scarring. Silicone gel, a medical device that is used to soften,
atten, and blanch hypertrophic and keloid scars to produce a
more aesthetically acceptable scar and increase range of motion
by improving scar elasticity. Clinical trials have already shown
that silicone gel sheets are safe and effective for the treatment
and prevention of hypertrophic and keloid scars if worn over
the scar for 12-24 h/day for at least 2-3 months.7 The purpose
of this study was to compare the effectiveness of silicone gel
and skin tape (tape closure) for the prevention of scarring in
surgical incisions wound in New Zealand white rabbits ears
with healed wounds (e.g., postsurgery). This study was focus
to provide a concern of efcacy for clinical scars management
of keloids and hypertrophic scars formation in future.
MATERIALS AND METHODS
The Animal Care and Use Ethical Committee of National
Defense Medical Center approved all procedures. Three New
Zealand white rabbits weighing 2.9-4.4 kg (5-7 months of age)
were kept under standard conditions.
Each rabbit received four incisions over two ears to which
silicone gel (Dermatix® silicone gel) and skin tape (3M™
Steri-Strip™ Adhesive Skin Closure) were applied to the upper
incisions, and the lower incisions were covered with sterilized
gauze and served as controls. The three New Zealand rabbits
that underwent 12 incision wounds and primary suture were
studied. One week later, the sutures were removed. Silicone
gel was applied directly to three surgical incision wounds
daily change dressings starting 1 week after surgery. Similarly,
the skin tapes were applied directly to another three surgical
incision wounds daily change dressings starting 1 week after
surgery for 3 months. The remaining six incision wounds were
left uncovered. The experimental design and working ow
chart is shown in Figure 1.
Prior to surgery, the ear dorsum was shaved, and the skin was
prepared with povidone-iodine. The rabbits were anesthetized
with an intra-abdominal injection of sodium pentobarbital
(30 mg/kg) and prepared for wounding. Approximately,
parallel incision wounds were created on the dorsal surface of
each ear down to bare cartilage. These wounds were sutured
primarily with 5-0 nylons [Figure 2]. Scarring severity was
assessed at 1, 2, 4, and 12 weeks after remove stitches using
Vancouver Scar Scale (VSS), Manchester Scar Scale (MSS),
and The Stony Brook Scar Evaluation Scale (SBSES).8
Statistical analysis
The data were analyzed using one-way analysis of variance,
and expressed as mean ± standard error. There are three
samples in each experimental group. Signicant differences
between groups were detected by value of P < 0.05 which was
considered to indicate statistical signicance.
RESULTS
Observation of wound healing in rabbit model is shown
in Figure 3. The observer was blind to the intervention. The
before and after VSS scores for each of the three groups were
statistically signicant (P < 0.05). At the beginning of injury,
the VSS scores for all parameters were high (less than lesion
control). Based on VSS parameters, there were reductions in
total scarring severity at 1, 2, 4, and 12 weeks in the skin tape
and silicone gel group. This reduction was maintained until
12 weeks for both groups, as shown in Figure 4. At week 1,
no statistically difference was observed between the two
treatments. At week 4, mean total scarring severity for the skin
tape group was 72% better than silicone gel group (4 vs. 5.5,
respectively). At week 12, mean total scarring severity for the
skin tape treated group was 42% better than the silicone gel
group (2 vs. 4.5, respectively).
Figure 1. Experimental design and working ow chart Figure 2. Images illustrating the surgical procedure
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Chih-Chien Wang, et al.:
197
The VSS scores with respect to scar vascularity, pliability,
pigmentation, and height are shown in Figure 5. Statistically
signicant differences were noted between the control and
experimental groups. In Figure 5a, at week 2, the score was
higher in the silicone gel group than in the skin tape group
(1.57 vs. 1.43, respectively), and signicantly different from
control group. This reduction was maintained until 12 weeks
in each study group, at which time the score in the skin tape
group was less than the silicone gel group (0.50 vs. 1.00,
respectively), and signicant different from control group.
Assessment of pliability is shown in Figure 5b. At week 1, the
pliability score was lower both in the skin tape and silicone
gel groups than in the control group (1.29, and 1.28 vs. 2.01,
respectively) with signicant difference. The reduction of
pliability score was maintained until 12 weeks in each group,
at which time a statistically signicant difference in pliability
was observed between the control and silicone gel group
(1.02 vs. 0.49, respectively, P < 0.005).
Assessment of pigmentation results is shown in Figure 5c,
and the results indicated that the skin tape treated group had
greater hypopigmentation than the control or silicone gel group.
At week 1, the difference between the skin tape and silicone gel
group was 0.13 (1.42 vs. 1.29, respectively), and only silicone
gel group is signicant different from controls. At week 12,
however, the skin tape group exhibited a greater reduction
in pigmentation than the silicone gel group (0.48 vs. 1.00,
respectively). Similar ndings were observed with respect to
height, as shown in Figure 5d. At week 1, both silicone gel and
skin tape were lower and signicantly different from control
group. Furthermore, silicone gel was lower than skin tape as
well (1.25 vs. 1.44, respectively). However, at 12 weeks, the
height was 0.51 in the skin tape group vs. 0.98 in the silicone
gel group.
All the scores associated with the items of MSS resulted
different between the three groups, especially in color,
appearance, and contour, as shown in Figure 6. Almost all
lesion control appeared grossly mismatching or obviously
mismatching in color, slightly proud/indented or hypertrophic in
contour and shiny in appearance. Wounds treated with skin tape
and silicone gel had a slight mismatch, ush with surrounding
skin or slightly proud/indented contour and matte appearance.
The reduction of MSS was a statistically signicant difference
was observed between the lesion control and silicone gel group
at 4 week (13.30 vs. 10.30, respectively, P < 0.005).
Figure 7 shows a histogram of the obtained SBSES scores.
Since the distribution between high and low SBSES scores
was very skewed, no correlation could be found between the
length of the incision and the resulting esthetic appearance, in
addition, the 12 weeks skin tape and silicone gel scars with
excellent to good results (4.50 vs. 4.75, respectively).
DISCUSSION
There are three stages of wound healing: Inammation,
proliferation, and matrix remodeling/scar formation. An
early inammatory cascade ensues immediately after injury,
during which much of the later outcome of scar development
is dictated. The exact mechanism by which inammation
promotes scarring is not known. However, it appears that the
development of scar is programmed during, and part of, the
inammatory process. Although an inammatory response has
traditionally believed to be a key event for wound healing in
adult skin, studies of fetal wound healing suggest that a high
level of inammation may promote scar formation rather than
enhancing wound healing. Scarring result from an abnormal
brous wound healing process in which tissue repair and
regeneration-regulating control is lost. This abnormal brous
growth presents a major therapeutic dilemma and challenge to
Figure 4. Evaluation of posttrauma scars by Vancouver Scar Scale (VSS).
Compare with the control lesions, silicone gel resulted in a efciency decrease
with total VSS scores at 1 week, but skin tapes had a signicant reduction of
total VSS score at 1, 2, 4, and 12 weeks
Figure 3. Observation of wound healing in the rabbit model. (a-d) Skin tape
covered group. (e-h) Silicone gel treated group. The upper sides of the ears in
each photo are the lesions treated with skin tape or silicone gel, and the lower
sides of the ear in each photo are the untreated control lesions
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e f gh
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Skin tapes versus silicone gel for posttrauma scar
198
the plastic surgeon because they are disguring and frequently
recur.9 Cutaneous scarring observed in wounds was dependent
upon the time, which has taken for the wounds to heal. For
the VSS, it is the most popular used scar assessment scale at
present; the same statistical measurements were examined and
compared with the results of the observer scale and the VSS.
In this prospective study, we have examined the effect of skin
tapes and silicone gel on re-epithelialization and scarring in
standardized incision wounds. There are still controversial
Figure 6. Evaluation of posttrauma scars by Manchester Scar Scale (MSS).
Compare with the control lesions, silicone gel resulted in a efciency decrease
with total Vancouver scores at 1 week, but skin tapes had a signicant reduction
of total MSS at 1, 2, 4, and 12 weeks. Star symbol (*) show a signicant
reduction (P < 0.05) compared to lesion control values
Figure 7. Evaluation of posttrauma scars by the Stony Brook Scar Evaluation
Scale (SBSES). It incorporates assessments of individual attributes with a
binary response (1 or 0) for each, as well as overall appearance, to yield a
score ranging from 0 (worst) to 5 (best). Compare with the control lesions,
skin tapes, and silicone gel resulted in an efciency increase with total SBSES
at 1, 2, 4, and 12 weeks
Figure 5. Statistically signicant differences were notes between the control and experimental groups. (a) Scar vascularity. (b) Scar pliability. (c) Scar pigmentation.
(d) Scar height. (a) Change of vascularity for the groups treated with skin tape and silicone gel. Star symbol (*) show signicant reduction (P < 0.05) compared
to control lesion values. (b) Change of pliability for the groups treated with skin tape and silicone gel. Star symbol (*) show signicant reduction (P < 0.05)
compared to control lesion values. (c) Change of pigmentation for the groups treated with skin tape and silicone gel. Star symbol (*) show a signicant reduction
(P < 0.05) compared to control lesion values. (d) Change of scar height for the groups treated with skin tape and silicone gel. Star symbol (*) show a signicant
reduction (P < 0.05) compared to control lesion values
ab
c d
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Chih-Chien Wang, et al.:
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studies on the efcacy of silicone gel for therapy of hypertrophic
scars, but no enough evidence is based on well-controlled
trials after treatment. In this study, the improvements of
VSS were initially treated with skin tape group and scores
decreased obviously after 2 weeks. Notably, the silicone
gel group was signicant improved with pliability than skin
tape group at 12 week, it has indicated that silicone gel may
improve proper remodeling of the scars, and then the mobility
and function would be restored within chronic wound healing
process. In contrast to silicone gel, progressive improvement
in vascularity, height, and pliability was observed in skin tape
group, though optimal improvement of scars thickness and
lightening of pigmented hypertrophic scars was not achieved.
The aim of our study was the comparison between the
skin incision wound treated with skin tape and silicone gel
to obtain the restoration and regeneration of posttraumatic
wounds. The measures of scar were satisfaction with cosmetic
result, which was assessment and based on the MSS. This
study also shows that the SBSES, to the best knowledge of the
authors the only well-validated instrument currently available,
is also useful in the evaluation of scars. A high satisfaction
with the cosmetic result was reported in both groups, with
no signicant difference in the SBSES. However, it has been
known the SBSES is designed for short-term measurement
in 5-10 days, and its assessment is either 0 or 1, → SBSES
is designed for short-term measurement in 5 to 10 days8, and
its assessment is either 0 or 1, which is not matched to our
experiments. As we understand, MSS and SBSES are more
emphasized on the color and shape in the assessments, but
vascularity and pliability are only for VSS, which might be
more easily observed in our experiments with the rabbit ears
that are composed of cartilages. Furthermore, MSS is more
arbitrary8 and has showed no signicant difference in all
groups except for the 4th week.
It is recommended that silicone gel need to be worn at
least 12 h/day for a minimum of 2 months. The mechanism of
action is unknown, but it has suggested that the greater wound
hydration achieved by using occlusive therapy (silicone and
nonsilicone-based) then affected local keratinocytes to alter
growth factor secretion and inuences broblast regulation. It
is also believed that hydration decreases capillary permeability,
inammatory and mitogenic mediators, and collagen
synthesis.10-14 Furthermore, the development of hypertrophic
and stretched scars in the treatment group only happened
after the skin tape was removed, it has suggested that tension
acting on a scar is the trigger for hypertrophic scarring. Skin
tape is likely to be an effective modality for the prevention of
scarring through its ability to eliminate scar tension.6 We have
assessed the scarring between these two treatments after suture
removed, and surprisingly the wounds treated with the skin
tape have showed a signicant improvement in scar formation
compared with wounds control and silicone gel.
We presented in this study a methodology to accurately
classify scar variables, and evaluate the occurrence of scars
during wound healing after trauma. The results demonstrated
that skin tape reduced scar formation as well as silicone gel.
However, the factors of efcacy and cost were important
consideration to satisfy for clinical requirement. In this
application of these scar prevention devices to reduce scar
formation after surgical incisions, skin tape and silicone gel
provide similar cosmetic outcomes for closure of surgical
incisions. Moreover, skin tape may represent a low-cost
alternative and low scar formation for closure of surgical
incisions.
ACKNOWLEDGMENTS
This study was supported by a grant from Tri-Service General
Hospital, National Defense Medical Center, Taiwan (TSGH-C101-174,
TSGH-C102-086). The authors thank Dr. Kuo-Jui Chen (University
of Adelaide, Australia) and Shu-Jen Chang (PhD student of National
Yang-Ming University, ROC) for data analysis.
DISCLOSURE
No benets in any form have been received or will be
received from a commercial party relating directly or indirectly
to the subject of this article.
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