Keywords
nipple - tattoo - breast reconstruction - NAC
Introduction
Nipple–areola complex (NAC) tattoos were first reported in 1975 by Rees.[1] Many reports have now investigated tattoo techniques[2]
[3]
[4]
[5]
[6] and this method has been widely used to provide finishing touches in breast reconstruction.
The choice of pigments is determined by discussions with the patient, mostly in comparison
with the color on the healthy side. Even with careful consideration, tattoo colors
gradually fade over time.[7]
[8] Many physicians perform tattooing empirically, and few reports have investigated
its effects and continuity.[7]
[8] Most of those studies were retrospective investigations of Caucasian populations,
and few prospective studies have examined tattooing. We therefore planned a prospective
study of NAC tattoos in Asian patients.
The purpose of this study was to reveal: (1) how long does it take for the fading
to stabilize, and what is the luminance rate of the affected side to the contralateral
side in 1 year? and (2) which pigment is most reproducible for NAC tattoos compared
with color samples?
Methods
This study prospectively investigated patients who underwent NAC tattooing after breast
reconstruction accompanied by cancer ablation between June 2010 and February 2014.
This study was registered with the University hospital Medical Information Network
(UMIN) clinical trials registry (UMIN000004986; https://center6.umin.ac.jp/cgi-openbin/ctr_e/ctr_view.cgi?recptno=R000005929).
During this period, NAC tattooing was performed on 60 sites in 59 Japanese patients,
including one bilateral case reconstructed with abdominal skin ([Table 1]). Duration of follow-up was defined as the period in months between the day of tattooing
and the day of post-tattoo photo. NACs were tattooed using a tattooing machine and
pigments (Permark; PMT Corporation, Chanhassen, MN) under local anesthesia. We chose
“flesh” series, the kinds of color chart.
Table 1
Patient demographics
|
Patient, n
|
59 (60 sites)
|
|
Age (years)
|
51.3 (SD 9.3)
|
|
Breast reconstruction
|
|
Abdominal flap
|
32
|
|
Latissimus dorsi flap
|
13
|
|
Breast implant
|
14
|
|
Breast conservation surgery with nipple resection
|
1
|
|
Nipple reconstruction
|
|
Modified C–V flap
|
60
|
|
Pigments
|
|
Flesh2.5
|
14
|
|
Flesh4
|
7
|
|
Flesh7
|
5
|
|
Flesh8
|
4
|
|
Flesh9
|
6
|
|
Flesh12
|
6
|
|
Others
|
18
|
Abbreviation: SD, standard deviation.
Photographs with a color reference marker (Casmatch; Bear Medic, Chiba, Japan) were
taken preoperatively, immediately after tattooing, and 1 week, 1, 3, 6, and 12 months
after tattooing. A single-lens digital camera (D90; NIKON, Tokyo, Japan) was used
under the same fluorescent lighting conditions. Photographs were standardized in terms
of luminance using Casmatch and Photoshop software (Adobe, San Jose, CA). Standardization
was done according to the manufacturer's instructions: in Photoshop, the sample range
of the eyedropper tool was set to an average of 5 pixel squares. In the Lighting Levels
correction, enter 230 for white R, G, and B; 40 for black R, G, and B; 121 for gray
R, G, and B, respectively. Open the photo with the Casmatch applied, select the white,
black, and gray eyedropper, and click on the white, black, and gray Casmatch in the
photo to correct the luminance. Then luminance and red, green, and blue (RGB) values
for the tattooed NAC, contralateral NAC, and normal breast skin near the contralateral
NAC ([Fig. 1A]) were analyzed using ImageJ software (U.S. National Institutes of Health, Bethesda,
MD). We conducted calculations only for the areolar area of the NAC, because the nipple
area was sometimes tattooed with a different color or affected by shadow. We also
avoided taking measurements in areas containing operational scars because it is difficult
to add pigment to scars ([Fig. 1B]).
Fig. 1 Method for measuring RGB values of NACs. (A) Yellow circle is normal breast skin near the nontattooed NAC. (B) Measurement site of the tattooed NAC. NAC, nipple–areola complex; RGB, red, green,
and blue.
Study 1: Red, Green, and Blue, and Luminance Changes Over Time
This analysis was performed at 46 sites of 45 patients, after excluding 4 sites in
4 patients who dropped out, 5 sites in 5 patients who received a second tattoo within
a year, and 4 sites in 4 patients for whom data were missing ([Fig. 2]). The skin types used in NAC reconstruction were abdominal (n = 25), dorsal (n = 11), or breast skin (n = 10). All nipple reconstruction methods are modified C–V flap.
Fig. 2 Flowchart showing patient selection.
This study further standardized RGB values by dividing RGB values for tattooed NAC
by those for normal breast skin near the contralateral NAC. Accordingly, we compared
the rate of RGB values for tattooed NAC with those for normal skin in this study.
RGB values were transformed to light intensity using a standard conversion.[9]
Luminance = 0.298912R + 0.586611G + 0.114478B
Luminance is a photometric measure of the luminous intensity per unit area of light
traveling in a given direction and represents the human perception of the brightness
of the light source.
We evaluated the change in RGB and luminance between preoperatively, immediately after
tattooing, and 1 week, 1, 3, 6, and 12 months after tattooing ([Fig. 3)].
Fig. 3 Representative progress of tattooed NAC. NAC, nipple-areola complex.
To adjust the time frame, we also calculated the fading rate by dividing five periods,
from immediately after tattooing to 1 week after, from 1 week to 1 month after, from
1 to 3 months after, from 3 to 6 months after, and from 6 months to 12 months after.
The following formula was used to determine the fading rate:
Fading rate (per month) = (Luminance at later period− Luminance at earlier period)/Luminance
at later period
Finally, we calculated the rate of tattooed/contralateral NAC luminance at 12 months
for 44 cases (44 sides), excluding bilateral abdominal case. Furthermore, the rate
of tattooed/contralateral NAC luminance was compared for the type of skin used for
NAC reconstruction.
Study 2: Reproducibility of Color
The analysis was performed for 34 sites in 33 patients after excluding 4 sites in
4 patients who dropped out, 2 sites in 2 patients with 2 unknown pigments, 17 sites
in 17 patients with pigments used at less than 4 sites, and 3 sites in 3 patients
(flesh2.5: 1, flesh4: 2) who received a second tattoo within a year ([Fig. 2]). This analysis examined the pigments for flesh 2.5, 4, 7, 8, 9, and 12 (Permark;
PMT Corporation, Chanhassen, MN), which were each used at four or more sites.
We also took photographs of the color samples of the tattoo pigments and standardized
the images with Casmatch. We regarded RGB values as three-dimensional data and calculated
the distance between the two points. That is, given the two points A (R1, G1, B1)
and B (R2, G2, B2), the distance (D) between these points was calculated using the formula:
D = √([R2 − R1]2 + [G2 − G1]2 + [B2 − B1]2) ([Fig. 4])
Fig. 4 RGB distance between two points. A (R1, G1, B1), B (R2, G2, B2), the distance D. RGB, red, green, and blue. D = √([R2 − R1]2 + [G2 − G1]2 + [B2 − B1]2)
Regarding color reproducibility, we targeted RGB values after 12 months. We compared
the RGB values of the tattooed part with those of the color samples.
Statistics
All statistical analyses were performed using EZR, which is a modified version of
R Commander designed to add statistical functions frequently used in biostatistics.[10] In changes over time study, repeated-measures analysis of variance (ANOVA) was performed
to assess whether there was an overall difference between time points. We then compared
the differences at each time point using paired t-test and Bonferroni correction while one-way ANOVA or unpaired t-test was used in other study. All tests with p-value less than 0.05 were considered significant.
Results
Study 1
R and B values were smallest at 1 week after tattooing, and G and luminance values
were smallest at immediate after tattooing. We used repeated-measures ANOVA to confirm
terms in which the RGB and luminance values changed significantly (R: <0.0001, G:
<0.0001, B: <0.0001, Luminance: <0.0001), and in which significant differences existed
between measurement time points using paired t-test and Bonferroni correction. In all elements, significant differences were seen
between pre and immediately after, 1 and 3 months, 3 and 6 months, and 6 and 12 months.
In case of G values, significant differences were observed between all neighboring
points ([Fig. 5]; [Supplementary Table S1] [available in the online version only]).
Fig. 5 RGB and luminance change in tattooed NACs (n = 46). Rate of RGB values for tattooed NAC with those for normal skin is shown. Plots
and bars show mean and standard deviation (SD) trends. Asterisks indicate significant
differences in repeated-measures ANOVA. ANOVA, NAC, nipple–areola complex; RGB, red,
green, and blue; ns, not significant.
The fading rate tended to decrease gradually from immediately after to 1 week, from
1 week to 1 month, from 1 to 3 months, from 3 to 6 months, and from 6 to 12 months,
and the standard deviation also tended to decrease. We also used repeated-measures
ANOVA for comparisons between fading rates in the five terms, but no significant differences
were identified (p = 0.19; [Fig. 6], [Supplementary Table S2] [available in the online version only]).
Fig. 6 Fading rate from immediately after to 12 months after tattooing. Plots and bars show
mean and SD trends. No significant differences were identified between the five terms
(p = 0.19) in repeated-measures ANOVA. ANOVA, SD, standard deviation.
At 12 months after tattooing, the rate of tattooed/contralateral NAC luminance was
mean 1.09 ± 0.13 ([Fig. 7]). No significant differences were observed in one-way ANOVA between the rates of
the three parts of skin from different donor sites (p = 0.63), with 1.11 ± 0.13 for the abdomen skin (n = 23), 1.08 ± 0.12 for dorsal skin (n = 11), and 1.06 ± 0.16 for the breast skin (n = 10).
Fig. 7 Rate of tattooed/contralateral NAC luminance at 12 months. Bars show mean and SD
trends. NAC, nipple–areola complex; SD, standard deviation.
Study 2
Subjects showed flesh2.5 (n = 12), flesh4 (n = 4), flesh7 (n = 4), flesh8 (n = 4), flesh9 (n = 5), and flesh12 sites (n = 5). We tattooed one patient with flesh7 at both NACs.
RGB value of each pigment and the distance from Red (R 255, G 0, B 0) and skin tone
to each pigment are shown in [Fig. 8]. Skin tone is defined as the mean value (R 209, G 172, B 146) of normal breast skin
near the contralateral NAC preoperatively. Thereby, flesh7, 8, and 12 were defined
as “reddish/dark,” and flesh2.5, 4, and 9 as “less reddish/light.” In both groups,
distances between tattooed skin and color sample of the pigment in the RGB dimension
were evaluated. The “reddish/dark” tended to be closer to the color sample than “less
reddish/light” in unpaired t-test, but no significant differences were identified (p = 0.16; [Fig. 9]).
Fig. 8 Classification of pigments by distance to Red or skin tone. The left table shows
the RGB elements of each pigment. The center graph shows the distance from red in
each pigment. The right graph shows the distance from skin tone in each pigment. From
these, we defined flesh7, 8, and 12 as “reddish/dark,” and flesh2.5, 4, and 9 as “less
reddish/light.” RGB, red, green, and blue.
Fig. 9 Distances between tattooed skin and color sample of the pigment in the RGB dimension.
The tattooed skin by reddish/dark (flesh7, 8, and 12) pigment tended to be closer
to the color sample than one by less reddish/light (flesh2.5, 4, and 9) pigment in
unpaired t-test, but no significant differences were identified (p = 0.16). Boxes and bars show mean and SD trends. RGB, red, green, and blue; SD, standard
deviation.
Discussion
In this study, we showed that (1) RGB and luminance significantly changed and faded
from 1 to 3, 3 to 6, and 6 to 12 months postoperatively, and (2) time-adjusted fading
rates showed a trend of decreasing fading during the same period, but no significant
difference, that is, fading continued even between 6 and 12 months, and (3) luminance
was 9% brighter than contralateral NAC at 12 months after, and (4) color reproducibility
tended to be higher with dark or reddish pigments.
During the early stages of acute inflammatory reaction after tattooing, keratinocytes
take up pigment particles and cells such as macrophages infiltrate the epidermis via
the destroyed basement membrane.[8] In the present results, despite the smallest luminance and G value immediately after,
the R and B values were the smallest 1 week later. And the fading rate was shown to
vary widely from immediately after to 1 week. These are presumed to be due to unstable
color, with bleeding, hemorrhagic plaques, inflammation, and crust formation occurring
immediately and for several weeks thereafter.
After a month, removal of pigment particles through the epidermis continues, but once
the basement membrane has reformed at the epidermal–dermal junction, the concentration
of pigment particles in the epidermis decreases. The epidermal–dermal junction normalizes,
and this process stops. Pigment particles are found only in dermal fibroblasts.[8] For this reason, the tattoo color is expected to change to some extent. Spear and
Arias reported that 9.5% of tattoos required touch-up during his study,[11] and Eskenazi noted that 10% of patients requested additional tattooing.[12] Furthermore, Hugo et al noted that 40% of tattooed NACs were blighter in color than
the color of tattooed NACs during the postoperative period and El-Ali et al noted
fading of the tattooed NAC in 34% of cases.[7]
[13] Even if the skin structure returns to normal, external stimuli such as ultraviolet
radiation and aging may contribute to fading.[14] The present results support these reports, and some fading of tattooed NACs is inevitable.
On the other hand, the fading rate between 6 and 12 months after tattooing is quite
small, although not significantly different, suggesting that the change in luminance
after 6 months is mild.
Comparing luminance of the tattooed and contralateral NACs for 12 months after tattooing,
the tattooed side basically was brighter than the contralateral side. El-Ali et al
also noted that tattoo color faded and symmetry between normal and tattooed sides
was 0.91 in color intensity values.[7] The luminance rate between tattooed and contralateral sides in our study was 1.09,
showing similar results to those described by El-Ali et al.
In terms of color reproducibility, pigments closer to red and darker than skin color
tended to reproduce better, while colors farther from red and closer to skin tended
to reproduce less well. One reason was that bleeding made it difficult to judge whether
sufficient tattooing had been achieved, resulting in insufficient tattooing. In fact,
“less reddish/light” pigment (flesh2.5, 1 and flesh4, 2) patients underwent a second
tattooing. This did not occur with “reddish/dark” pigment. El-Ali et al recommended
that tattoos start at about one-third darker than the color of the nipple on the normal
side,[7] but since a few cases in the current study occurred darker than the healthy side,
our current goal is the same color as the color chart, and a second tattoo is performed
if it is blighter.
The clinical significance of this study is that it shows objective data on tattoo
fading in Asians, along with RGB changes, that the fading rate tends to decrease over
time, but still fades between 6 and 12 months, and that the color reproducibility
may vary depending on the inked color. These findings are useful to explain to patients.
Several limitations to this study must be kept in mind. As these data used values
of luminance with RGB values, we did not evaluate differences in color accurately.
There are various ways to represent color, including RGB, CMYK, and Laboratory, and
there is some controversy as to whether RGB is appropriate for color evaluation.[15] However, to evaluate digital photographs on a monitor, we used RGB, which is the
color representation method in monitors. Additionally, the sample size for each pigment
was small in Study 2. Despite these limitations, this study represents the first prospective
evaluation of luminance, fading rate, and color reproducibility for tattooed NACs
in Asian patients.
Although no Food and Drug Administration-approved pigments for medical tattooing have
been released and fading is inevitable, tattoos containing iron oxide and titanium
dioxide can be safely provided.[16] When the color of a tattoo becomes stable is still unclear, so follow-up is warranted
where possible.
Conclusion
Prospective evaluation of RGB, luminance, fading rate, and color reproducibility for
tattooed NACs was performed in Asian patients. RGB and luminance varied widely from
immediately after to 1 month after tattooing. The fading rate tended to decrease as
time progresses but fading is significant and still occurs between 6 and 12 months.
Luminance was 9% brighter than contralateral NAC at 12 months after. Color reproducibility
tended to be higher with reddish/dark pigments.
