BACKGROUND. Recent technological advances have dramaticaly increased t
he use of lasers in skin resurfacing. The first high power short pulse
laser, Ultrapulse, has found extensive use iii dermatology and plasti
c surgery for skin resurfacing. Reports for penetration depth are at b
est anecdotal. To our knowledge this is the first report of histologic
al effects of the Ultrapulse in human skin. OBJECTIVE. To determine th
e effect of single and repeated (two or three) Ultrapulse laser impact
s on volar forearm skin. METHOD. The volar surface of the arm in four
patients received in adjacent areas either one, two, or three pulses,
after anesthesia. The treated areas were immediately biopsied, hematox
ylin & eosin prepared, and examined. RESULTS. Increasing the number of
passes correlates with increased depth of penetration and thermal abl
ation. No significant propagation of destructive thermal energy to adj
acent tissue was noted. CONCLUSION. One impact at the tested parameter
s ablated most of the epidermis. Two impacts superimposed ablated the
entire epidermis and the superficial papillary dermis. Three superimpo
sed impacts penetrated to the reticular dermis. (C) 1996 by the Americ
an Society for Dermatologic Surgery, Inc.