Presidential Greeting - American Society for Laser Medicine and ...

56 American Society for Laser Medicine and Surgery Abstracts
ureteral stricture formation. Compared to the controlled holmium
energy source, Nd:YAG causes a deeper tissue effect. Based on
these findings, we typically prefer to use the holmium laser for all
ureteral lesions.
#190
PHOTOCHEMICAL TISSUE BONDING: A
POTENTIAL STRATEGY FOR TREATING LIMBAL
STEM CELL DEFICIENCY
Chuan Gu, Robert Redmond, Irene Kochevar,
Min Yao, Ying Wang
Wellman Center for Photomedicine, MGH, Harvard Medical
School, Boston, MA
Background: The goal of this study was to determine the
feasibility of using a new light-activated method for attaching
human amniotic membrane (HAM) pre-cultured with limbal stem
cells (LSCs) to the cornea.
Study: LSCs were isolated from the eyes of rabbits, and then
cultured on denuded HAM to create grafts. These were then
transplanted onto rabbits with an eye limbal stem cell deficiency
(LSCs) and secured either by sutures or by photochemical tissue
bonding (PTB). Evaluated outcomes included corneal opacity,
inflammation, neovascularization, and collagen alignment.
Results: The isolated and cultured cells were verified to be LSCs
based on their K19 þ /intergrin b1 þ /P63 þ /K3 properties.
Securing the graft with PTB provided better outcomes than that
with sutures. At 28 days post-surgery, the corneal opacity scores
were significantly lower in PTB treatment compared with sutures
(0.75 0.5 vs. 1.75 0.5, P < 0.01). Similarly,
neovascularization scores were also lower in PTB treated
animals (0.75 0.5 vs. 1.5 0.57, P < 0.01). For PTB treated
samples, the quantification of MPO and CD31 levels from
immunofluorescent images indicated less neutrophil infiltration
(5.25 2.21 vs. 13.25 3.09, P < 0.01) and less
neovascularization (2.0 0.81 vs. 6.25 1.25, P < 0.01)
forming at the wound site. The collagen alignment shown in
immunofluorescent and second harmonic generation images
was better organized than those in the suture group.
Conclusion: Compared to suture attachment, the light-activated
technique is a promising modality for treating patients with
LSCD. Attaching LSC grafts with PTB produced improved
outcomes.
#191
SURFACE TEMPERATURE DISTRIBUTIONS IN
RABBIT AURICULAR CARTILAGE FOLLOWING
LASER CARTILAGE RESHAPING WITH CARBON
DIOXIDE SPRAY COOLING
Edward C. Wu, Victor Sun, Wangcun Jia,
Dmitriy E. Protsenko, Cyrus T. Manuel,
Brian J.F. Wong, J. Stuart Nelson
Beckman Laser Institute and Medical Clinic,
University of California, Irvine, CA
Background: Laser cartilage reshaping (LCR) used in
conjunction with cryogen spray cooling is a promising modality for
effecting cartilage shape change while minimizing cutaneous
thermal injury. However, LCR in thicker tissues such as auricular
cartilage generally require higher laser power, thus increasing
surface cooling requirements. To eliminate the risks of freeze
injury characteristic of high cryogen spray pulse rates, we propose
instead a carbon dioxide (CO 2) spray, which evaporates quickly
and does not deposit for significant periods of time on the skin, as
the cooling medium. This study aims to identify optimal
parameters to perform LCR with CO2 spray cooling in ex vivo
rabbit auricular cartilage; specifically, to determine the effects of
laser dosimetry and CO2 cooling parameters on the spatial and
temporal evolution of surface temperature.
Study: Parameters used in previous LCR studies with cryogen
spray cooling were used to approximate optimal laser dosimetry
and cooling parameters. Excised whole rabbit ears were irradiated
at three sites with a 1.45 mm wavelength diode laser (13–14 J)
with concomitant application of CO 2 spray (pulse rate 25–
85 milliseconds, 1–4 cycles) to the skin surface. Surface
temperature distributions were measured during irradiation.
Results: At either laser dosimetry, skin surface temperature
reached 808C above 2 heating/cooling cycles. Gross inspection
showed significant cutaneous injury of the irradiated sites with
minimal cooling (25 milliseconds pulse duration). Increasing
cooling pulse duration demonstrated improved skin protection
during irradiation.
Conclusion: Due to its minimal risk of frostbite during prolonged
application to tissues, CO2 spray cooling can potentially serve as
an alternative to cryogen spray cooling in LCR, and may be the
preferred cooling medium in thicker tissues. At this time, the
optimal laser dosimetry and cooling parameters are still being
explored. Future studies evaluating preclinical efficacy in an in
vivo rabbit model are underway.
#192
LASER ASSISTED FACIAL RHYTIDECTOMY AND
FACIAL REJUVENATION: A REVIEW OF THE
FIRST 500 PROCEDURES
Richard Gentile
Northeastern Ohio College of Medicine, Youngstown, OH
Background: In 2006 the FDA approved the SmartLipo TM laser
for subcutaneous lipolysis as well as use on soft tissue. In 2007 we
began using the 1,064 Nd:YAG laser as an adjunctive technique
for rhytidectomy specifically using it to elevate the facial flaps. An
immediate observation in our early procedures was a significant
and reproducible reduction in facial flap bleeding due to the
presumed hemostatic effect of the pulsed laser. We then began
routinely using the laser for facial flap elevation as well as
forehead and neck rhytidectomy. In addition to the hemostatic
effects of the laser skin tightening and firming are evident due to
dermal heating and concurrent laser lipolysis.
Study: A retrospective review of over 500 procedures completed
with laser assisted facial dissection was conducted. The
procedures were carried out by the same surgeon at the same
facility and include laser irradiation intended to promote laser
lipolysis, interstitial heating and laser contouring procedures. The
aesthetic results are reviewed as well as the improvements in
hemostasis and operating times.
Results: The photographs pre- and post-operative were examined
to evaluate whether or not the objectives of the surgery were met
and for evidence of skin tightening and correction of facial laxity.
The improvement in hemostasis were evaluated on the basis of
sponge counts and photodocumentation. Over 95% of patients
demonstrated significant improvement from their preoperative
status in terms of aesthetic improvement.
Conclusion: FiberLaser assisted facial rhytidectomy and facial
rejuvenation or SmartLifting TM allows for the coagulation of
small blood vessels in the subcutaneous plane preserving the