Biomedical Engineering Reference
In-Depth Information
(
A
)
(
B
)
(
C
)
Figure 7.8
Erbium-doped:yttrium-aluminum-garnet fractional laser (
A
) before and (
B
) 3 months after three treatments 1 month apart (60% coverage and
250-μm depth per treatment; microwounds were 150 μm in diameter); (
C
) immediately after treatment.
striae. Side effects were mild, the most common being postin-
fl ammatory hyperpigmentation (PIH), which resolved in 4 weeks
(23). Another study compared nonablative fractional resurfacing
and ablative fractional resurfacing (AFR) in striae and found
both to be effective, where about 35% and 50% of patients,
respectively, were observed to have at least 26% global improve-
ment in the appearance of the lesions (24). The ablative laser used
in the study was a CO
2
laser (eCO
2
, Lutronic) that deployed
100 pixels/cm
2
at 40-50 mJ over three treatment sessions 1 month
apart. PIH was observed in the majority of AFR patients, and
overall the ablative-treated side showed greater erosions and
oozing.
The authors have studied an RF pixel device (Alma Lasers,
Buffalo Grove, Illinois, USA) that creates 150-
One of the editors (MPG) has not found an acceptable degree of
effi cacy with using the Active or Deep FX CO
2
laser due to mini-
mal improvement associated with 3-9 months of PIH in treated
patients even with a Fitzpatrick skin type II. Additional work
with other wavelengths and/or energies will be necessary to
achieve reproducible improvement with minimal adverse events.
Syringomas
Syringomas present a challenge in attempting to treat effec-
tively without recurrence and without leaving a conspicuous
scar. Cho et al. investigated the application of fractional CO
2
to
these lesions. His group treated 35 patients with a fractional
CO
2
laser with two sessions at 1-month intervals. The laser
delivered 100 mb/cm
2
with two to three passes equivalent to
about 20% density. Seventy percent of the patients were
reported by the rating physicians to have between 25% and
75% improvement in the global severity of the syringomas.
They also found that the maximum depth of the wounds was
near the mean depth of the syringomas via biopsy (25).
m-diameter
“plasmas” with a rolling mechanism. The plasma energy was
applied in fi ve patients with striae alba and showed a mean of
about 50% improvement with follow-up at 3 months after
4 monthly treatments. The plasma generated by the RF device
creates microwounds across the skin over eight passes (Fig. 7.11).
μ
