Biomedical Engineering Reference
In-Depth Information
(
A
)
(
B
)
Figure 2.25
Warts (
A
) before and (
B
) after five PDL sessions one month apart. (7 mm 12 J/cm
2
, 1.5 ms). No cooling was used.
anesthetics, injectable anesthetics, cool air, or a slight amount
of DCD (20 ms spray/10 ms delay). The lesions should be
pared down prior to treatment. They then become black after
24 hours. Patients are retreated every 2 to 3 weeks until resolu-
tion. No cooling is applied; however, some ice before and after
can mitigate discomfort.
IPL (188): Another system that incorporates both vascular
specifi city and thermal effects is the IPL. As previously described,
this system produces deep vascular coagulation and thermal
effects. We have achieved excellent success with this modality.
With the IPL, the wart is exposed through a hole-punch in a
white index card. The IPL crystal is then placed on the wart,
which is exposed through the hole-punch. IPL energy does not
penetrate through the white index card and the treatment is not
painful. With the IPL a 550-, 560-, or 570-nm fi lter is used, with
a double pulse of 2.4 and 4.0 ms, or 3.0 and 3.0 ms (with the
Lumenis One) with a 10-ms delay between the pulses, 45 J/cm
2
(30 J/cm
2
with the Lumenis One) is used; one to three pulses are
given until the wart turns gray. Nd:YAG lasers (189,190) have
also been applied to warts with variable success. The IPL was
applied both with and without paring in one study. Settings
were applied with a 10 mm smaller crystal (Ellipse Flex IPL,
Denmark) with a 400-950 nm fi lter. A dual pulse mode was used
26-30 J/cm
2
at 5.5 ms separated by a 2-ms interval. The end-
point was sight graying. which sometimes require fi ve passes.
three treatments at three-week interval were applied. Less than
50% of the verruca completely responded after the last treat-
ment. Furthermore, paring alone resulted in similar responses
in this particular study. In the Han study, warts were treated an
average of 1.5 sessions 4 weeks apart at 200 J/cm
2
, a 5 mm spot,
and contact cooling. After four sessions, 96% of lesions had
cleared. Relapses were uncommon. Biopsies showed destruction
of blood vessels. Lesions required injectable anesthetic.
The frequency doubled Q-switched Nd:YAG laser has also
been found to be effective in the treatment of fl at warts. This
laser was used with a 3-mm-diameter spot size at 2.5 J/cm
2
with
multiple 10-ns pulses. Lesions were treated until whitening
occurred and all lesions turned into eschars after a few days.
In the seven patients treated, hyperpigmentation developed but
all lesions resolved without adverse effects. Finally, the treatment
of warts in sensitive areas such as the anogenital region is less
traumatic with the PDL than with conventional techniques.
that blue-red lesions do respond at least 50% to purpuric
settings with PDL (191).
Pyogenic Granuloma
This is an acquired vascular lesion, a true neoplasm distinct
from granulation tissue, usually solitary, 0.5-2.0 cm in diam-
eter, bright red, and pedunculated. The surface is soft, bleeding
easily with trauma. It may become ulcerated and develop a
granulomatous surface with a brown or black crust. Lesions
usually appear suddenly and may enlarge rapidly. These lesions
also frequently occur as a superimposed growth on the surface
of a PWS. Repeated episodes of bleeding and unresponsive-
ness to electrocautery have been reported in up to 50% of
patients. This may be secondary to the extension of vascular
proliferation deep into the dermis, often with a unique lobular
arrangement of capillaries. The CO
2
laser has been shown
to be effective in treating PGs. The PG is photocoagulated
until the entire lesion blanches and turns a dusty gray color.
Treatments are repeated at three- to four-week intervals as
needed (Fig. 2.26) (192).
PG lesions have been unpredictably responsive to the PDL
(193). They have been shown to respond, but in most cases
lesions are too thick for the laser to penetrate throughout the
lesion in one treatment. Tan and Kurban (194) use a glass slide
to compress the superfi cial ectatic vessels and use the laser
through the glass to treat the deeper component of this lesion.
This maneuver presumably allows treatment of deep vessels,
after which the slide is removed and the treatment is repeated
to coagulate more superfi cially located vessels. When effective
by itself, the PDL must be used with multiple, 100% overlap-
ping pulses to turn the lesion deep purple.
A study of 18 patients with PG treated with the PDL demon-
strated both symptomatic and clinical clearing in 16 patients
with excellent cosmetic results (195). Seven of the lesions had
been previously treated with electrosurgery or excision. The
authors fl attened the lesions with a glass slide and used fl u-
ences of 6.5-9.0 J/cm
2
in an overlapping manner to cover the
lesion completely. Treatments were repeated up to four times
to achieve success. Treatment outcomes were excellent, but two
postoperative photos showed textural changes that resembled
a scar, although this was not noted by the authors. We have not
been able to achieve uniform success in treating PG lesions
with or without the diascopy maneuver with the PDL. In addi-
tion, multiple treatments are impractical because of the ease
with which lesions are traumatized between sessions. We
therefore recommend shave excision of the lesion's papular
Lymphangioma Circumscriptum
Although it is not primarily a vascular lesion, some vascular
lasers have been applied with variable success. We have observed
