DEFINITIONS
PORT-WINE STAIN (MALFORMATION)
"STRAWBERRY" BIRTHMARK (HEMANGIOMA)
Port-wine stain is a nonmedical description for what is most exactly termed a congenital capillary malformation (port-wine variety). Port wine stains have incorrectly been called hemangiomas (even in the medical literature), but confusion over what one should actually call these lesions has been cleared considerably by looking at histological differences between the various clinical types of cutaneous vascular lesions and classifying them accordingly. Mullikan has found that vascular lesions with mature-appearing, orderly, nonproliferating endothelial cells lining the vascular spaces and with relatively low numbers of mast cells are unlikely to enlarge dramatically with passage of time, and are similarly not going to involute or "go away." These congenital lesions are termed malformations. However, vascular lesions with less-orderly, immature-appearing, proliferating endothelial cells and high numbers of mast cells frequently progress and enlarge markedly, and can subsequently regress or involute; these are termed hemangiomas.
The congenital capillary malformation (port-wine variety) is the most common cutaneous vascular lesion that does not involute. Port wine stains do not "go away," regardless of how long one may wait! Hemangiomas, however, can enlarge to significant proportions (usually faster than the infant's growth rate), are usually not seen at birth, and do not always look like a "strawberry." Likewise, not all vascular lesions that look like "strawberries" are hemangiomas, as venous or capillary-venous malformations can look remarkably similar to hemangiomas.14
While it is clearly recognized that some hemangiomas can grow to significant size, altering growth of adjacent structures, damaging overlying skin or underlying tissues (including bone), and bleeding or becoming infected, it has frequently been overlooked that port-wine variety capillary malformations can also cause soft-tissue and/or bony growth disruptions. These changes occur much less rapidly, and (usually) at an older age, but they occur nonetheless in a majority of these patients. Thus, treatment to correct or improve the congenital vascular abnormality is reconstructive rather than "cosmetic," though certainly the disfigurement may be improved as well. In addition, since the tissue changes associated with these vascular abnormalities are only partially or not at all reversible once they occur, appropriate treatment is recommended to prevent and avoid these complications, whether the lesion is a malformation or hemangioma.

PORT-WINE STAIN INCIDENCE, SYNDROMES, AND STATISTICS
The incidence of congenital capillary malformation (port-wine variety) is 0.3% (3 per 1000 births), with an equal sex distribution. Many are located on the face in the distribution of the trigeminal nerve. Other locations anywhere on the body are also seen, but with lower frequency. Five percent of all port-wine patients have other associated congenital abnormalities such as glaucoma and seizures, due to vascular abnormality in the eyes and brain (Sturge-Weber syndrome ), or bony and soft tissue growth disturbance (gigantism) and varicosities (Klippel-Trenaunay syndrome ). Even in the 95% of patients without these additional abnormalities, port-wine variety congenital capillary malformations darken in color as the patients age, cause soft tissue hemihypertrophy (thickening in the affected skin, lips, eyelids, or other areas), and by middle age often develop fragile vascular nodules, papules, or thin-walled blebs ("cobblestoning") that can bleed seriously with minor trauma or become infected more easily than normal uninvolved tissue. Shaving of the beard area can become impossible unless treatment prevents or corrects these secondary changes.

Despite the unwillingness of some insurance companies, HMOs, or other third party payers to consider the psychological morbidity of these congenital vascular abnormalities, the effect on such a "marked" patient's emotional and personality development is significant. Left untreated, the additional thickening and disfigurement of tissues in the affected area further aggravate the real and perceived differences from other people. The physical/medical morbidity of these congenital vascular abnormalities is also significant. By the fifth decade of life, two-thirds of port-wine stain patients will develop secondary complications that could have been prevented or minimized by early laser therapy.13,18 Thus, effective treatment from all standpoints is best instituted at as early an age as safely possible. However, treatment at any age should be considered correction or improvement of a congenital abnormality, and prevention or treatment of complications. This is functional rather than cosmetic surgery, and is reconstructive regardless of the surgical tools used, including laser.

LASER TREATMENT
RUBY, CO2 , Nd:YAG LASERS
Interestingly, virtually all of the medically available lasers have at one time been utilized in the treatment of port-wine stains and other vascular lesions, regardless of their emitted wavelength or absorption characteristics of cutaneous and/or vascular chromophores. The initial ruby laser (1960) and later red lasers have little or no absorption by hemoglobin or oxyhemoglobin, and produced an effect only when utilized at energy levels that produced nonspecific thermal burns to epidermis, dermis, and vessels, with resultant hypopigmentation and scar formation. CO2 laser (far infrared) energy is highly absorbed by all tissues containing water, and similarly produces nonspecific thermal burns, albeit at a precisely shallow depth (depending on energy levels). Although some investigators have reported good results with CO2 laser treatment of port-wine stains, the overall success rate is unacceptably low and the scar rate unacceptably high because of the nonspecific tissue absorption of thermal energy. , This is particularly understandable considering the significant thickness of water-containing tissue between the epidermal surface and the abnormal port-wine vessels at 0.3 - 1.5mm, all of which must either be vaporized or superheated before the abnormal vessels are heated enough to cause coagulation. Even with satisfactory reepithelialization (no hypertrophic or keloidal scarring), the result was often a slightly depressed or flat, shiny, hypopigmented patch replacing the previous flat pink or red patch. These "lightened" areas were as different from normal uninvolved skin as was the initial birthmark, since these areas do not tan, blush, or exhibit normal skin texture. Similar nonspecific energy absorption, thermal burns, and scars are seen with the Nd:YAG laser (near infrared), which has the additional disadvantage of causing coagulation necrosis to a depth of 5 - 7mm, because of its relatively poor absorption by all tissue chromophores, including oxyhemoglobin, melanin, and water.

ARGON LASER
Until development of the newest yellow-wavelength lasers, only the argon laser (488, 514nm, blue-green light) was thought to have characteristics suitable for ablation of cutaneous vascular lesions: some absorption by oxyhemoglobin, fair depth of penetration into skin (0.3mm for 50% of energy), and thereby satisfactory selectivity. By 1976, the argon laser was emerging as the treatment of choice for port-wine stains and was enthusiastically utilized by many physicians. , However, time and experience with this initially "much-hyped" modality has demonstrated that the argon laser is far from the "ideal" in both effectiveness and complication rate.8,20
We now know that the argon wavelengths (488, 514nm) actually fall in an oxyhemoglobin absorption trough (Fig. 1), and that another cutaneous chromophore, melanin (the skin pigment), has significant absorption at these wavelengths. Because of this energy absorption within melanin as well as within the abnormal vessel, the skin receives enough energy to cause second-degree burns, with subsequent scarring. Moreover, the shortest exposure time commonly used with the continuous wave argon laser was 100msec (0.1 seconds, with a spot size of 1mm and power of 2-4 watts), which causes thermal necrosis in a zone equal to approximately twice the distance between venules and to a depth of 0.5mm. Thus, the initial specificity induced by oxyhemoglobin's selective absorption of the blue-green laser light is totally lost because of the subsequent nonselective thermal injury to perivascular dermis. These dermal burns induced extensive and unsatisfactory scarring in many patients. Dixon et al (1984)8 reported scar rates as high as 25% in adults, and nearly double that in children, as well as the same permanent hypopigmentation and texture changes noted with previous lasers (seen in as high as 86% of argon-treated patients). This certainly show that this modality is far from "ideal." Although the literature commonly notes a relatively low incidence of hypertrophic scarring, a scar is defined as any departure from normal skin color, texture, or architecture, and even the most skilled and experienced physicians utilizing argon lasers for port-wine stains continue to report a high proportion of hypopigmented, shiny, and/or slightly depressed scars. Though these patients were not usually included in the "poor result" group, they should actually be added to the statistics including those patients with little or no lightening (no scar), and those with hypertrophic scarring. Additionally, a learning curve of many months is accompanied by an unacceptably high scar rate, until the physician becomes proficient enough to reduce this rate to an "acceptable" one.
Because of these difficulties, and because of the thinner and more easily damaged skin in infants and children, young port-wine stain patients were not even considered candidates for argon laser treatments, and parents were advised to wait until their children reached adulthood to better the odds of avoiding permanent scars. , Fortunately, many port-wine stain patients were wisely counseled to wait until better treatments became available. Now that the yellow-wavelength lasers are in clinical use, a similar skepticism as developed with prior "better" treatments is certainly understandable.

PULSED DYE AND OTHER YELLOW-LIGHT LASERS
However, the yellow-light lasers now in clinical use have been used in experimental protocols for over 15 years, were FDA-approved for clinical use in the summer of 1988 (in this country; clinical use in other countries has been carried out for many more years), and have been extremely, if not spectacularly, successful for many patients. Scar rates of less than 2% overall, and less than 6% in children, , have been reported and confirmed by others for these "new" lasers, in several thousand patients thus far treated over the past decade and a half of yellow-light laser development. Since we began clinical use of these lasers in 1988 (initially at the Laser Center-Abbott Northwestern Hospital, Minneapolis, MN; now the Minimally Invasive Care Center-Abbott Northwestern Hospital, and Children's Hospital Minneapolis) the incidence of hypertrophic scarring has been under 0.3%, and mild scarring, cutaneous textural change, or hypopigmentation has been limited to less than 5% of several thousand cases. About half of the patients with scarring have not noted resolution with time, and may require dermabrasion, laser resurfacing, or other techniques to deal with these treatment effects. The scarring has thus far been limited to textural irregularities similar to depressed chicken pox scars, or raised bumps in some cases, and have occurred most commonly in infants or in areas of clothing or other irritation. In other cases, the changes have been temporary, and have resolved with time and conservative management. Proper care of any irritated or blistered areas after laser treatment is essential in order to prevent scarring, which can be caused by drying-out and scabbing, scratching or picking, or superficial infection of these open spots. Keeping any open blistered areas clean with antibacterial soap and water, followed by application of antibiotic ointment (Polysporin or Bacitracin) to keep the wound moist as it heals will minimize the risk of permanent scarring.

LASER DESIGN AND PHYSICS
PULSED DYE LASER
Basic research in laser-tissue interactions has allowed experimental predictions of optimal wavelength, dose, and pulse duration for treatment of vascular lesions. Parrish, vanGemert, Anderson, and other workers have predicted and shown experimentally and clinically that yellow laser light at 577nm can selectively target oxyhemoglobin without damaging surrounding tissue.23 This is possible because oxyhemoglobin has a b-absorption peak at 577nm, whereas the argon wavelengths (488, 514nm) fall in an oxyhemoglobin absorption trough. Also, melanin has less absorption at 577nm than at the blue-green argon wavelengths. In addition, considerable research into the thermal relaxation times of microvessels (0.01 - 0.15mm) has shown that certain pulse durations of the laser light minimize thermal transmission beyond the confines of the target vessel. 23, This limits the thermal injury to the vessel alone, sparing the surrounding dermis and epidermis, and preventing scarring. This process, in which vascular lesions are treated by appropriately timed short-pulse laser light, is termed selective photothermolysis.
Pulsed yellow laser light was first produced by using a high-output xenon flashlamp to "pump" an organic rhodamine-g dye in liquid solvent, which then emitted coherent light in yellow wavelengths. This high-energy, short pulse duration yellow laser output can be filtered optically (tuned) to the exact desired wavelength, which is chosen to correspond to oxyhemoglobin's absorption peak at 577nm. Pulse durations of 25 - 450msec were calculated to correspond to the thermal relaxation times of microvessels around a size of 40mm, which is an average vessel size in a child's port-wine vascular malformation. These initial flashlamp-pulsed tunable dye lasers thus represented a major breakthrough in treatment of cutaneous vascular lesions without the scarring seen in all previous treatment methods. Initial versions of this type of laser were extremely expensive, bulky, non-moveable, water-cooled, 220V single-phase electrically powered, high peak power output, fixed spot size, slow repetition rate machines that required critically precise alignment, frequent (expensive) dye changes due to rapid dye degradation, and frequent service calls. To improve reliability in these early models, pulsed dye laser manufacturers eliminated wavelength choice ("tunability") by preselecting the exact yellow wavelength. In the earliest versions, this was 577nm (corresponding to the oxyhemoglobin absorption peak), but 585nm was subsequently chosen for later models of this laser, as longer wavelengths allow slightly better penetration of the dermis by the laser light, first described in 1990 by Tan et al. Likewise, the pulse duration (450msec) and spot size (5mm) were manufacturer-selected and are not user adjustable. The newest versions of the pulsed dye lasers are less expensive, more reliable, and even mobile (in specially equipped trucks or vans), do not require water hook-up (internal radiators for cooling), have more rapid pulse repetition rates (one pulse per second), have multiple spot sizes (3, 5, 7,and10mm), and require dye changes every 75,000 pulses as compared to every 5000 pulses in previous versions. At least two companies now produce commercially available pulsed dye lasers.

TUNABLE DYE (CONTINUOUS) LASER
Other manufacturers have developed dye lasers in which the rhodamine dye is energized by one or two continuous-output argon laser tubes, allowing continuous-wave yellow laser output which can then be shuttered or gated (often confusingly called "pulsed") to durations as short as 0.02 second (20msec, 20,000msec). These beam durations are longer than the thermal relaxation times for the microvessels in an infant or child, and are even slightly longer than the thermal relaxation time for an adult's larger port-wine stain microvessels. Therefore, the longer shutter durations necessitated by the low power output of this laser (1.0 - 2.0 watts) cause more thermal damage to surrounding tissues, though less than seen with the argon laser. These tunable dye lasers have selectable wavelength from the argon blue or green to the entire range from yellow (577nm) too red (630nm), which may become important as other applications such as photodynamic therapy come into use. These lasers have variable spot size (0.05 - 6.0mm), avoid the need for flashlamp changes, but are still expensive, bulky, nonmoveable, water-cooled machines. Although the continuous laser output can be "shuttered" as noted above, and handpieces have selectable larger spot sizes, the low power output restricts useability to small spot sizes (usually 1 - 2mm at most) or longer shutter durations which increase thermal damage. Dye degradation is less (due to low power output), requiring less frequent dye changes, and several present versions are able to achieve reasonably reliable, rapid repetition rates for cutaneous vascular lesion treatment. For photodynamic therapy applications (still presently in FDA phase three protocols), scientific tunable dye laser versions are recommended, as they are able to generate and sustain the higher power red light output necessary for PDT applications. Commercial tunable dye lasers are generally ophthalmic lasers that can generate only 1 - 2 watts at maximum output, which must be maintained for sustained dosing periods, often taxing the laser's capabilities considerably.

COPPER VAPOR LASER
A third type of yellow-light laser does not use rhodamine-g dye at all, but instead uses copper pellets as the lasing medium. Thus, the copper vapor laser is not a "dye laser" at all, though it emits yellow light at a wavelength of 578nm. In this laser, the resonant cavity is a neon-gas filled tube with copper pellets at each end. Heated to 1600 degrees Celsius, the copper vapor creates a coherent simultaneous output at yellow (578nm) and green (511nm) wavelengths. The copper vapor laser has an extremely short (20nsec, 0.02msec) on-time followed by an average 100msec off-time in a true pulsed output at approximately 11kHz. Although peak power is about 10 kilowatts, since the laser is off much more than it is on for any shutter duration, average power output is only 1 - 2 watts. This is sufficient for cutaneous vascular lesions, as noted with the tunable dye laser, though with the penalty of slightly more thermal damage than the pulsed dye laser, and less thermal damage than the tunable dye laser. Since the copper vapor laser is a true pulsed laser with an extremely high repetition rate, it can be considered as a quasi-continuous output laser that can be shuttered or gated like the tunable dye laser. Multiple spot sizes are available up to 1mm, and this laser can be utilized with a computerized scanner delivery system to treat large areas such as port-wine stains, as can the tunable dye laser. The copper vapor laser is air-cooled, not requiring plumbing hook-up, and is somewhat less expensive than the other yellow-light lasers, but is still bulky, relatively nonmoveable (though alignment is less critical than with the dye lasers), and is not tunable. A gold vapor laser utilizing the same design can emit red light at 628nm for photodynamic therapy use, but the gold tube is not easily interchangeable with the copper tube.
Other yellow-wavelength lasers, such as the copper bromide laser, offer the possibility of even more efficient high-power, appropriate-pulse-duration output that can be mated to area-mapping automatic computerized scanners for extremely rapid treatment of large-area cutaneous vascular abnormalities. Additional variations in higher-power lasers at varying wavelengths, longer pulse durations (for larger vessel sizes), and spot sizes or configurations are under investigation.

KTP LASER, Q-SWITCHED Nd:YAG LASER
Another laser approved by the FDA for treatment of vascular lesions is the KTP laser, which is a frequency-doubled Nd:YAG laser operating at 532nm (green). This laser utilizes a Potassium (K) Titanyl (T) Phosphate (P) crystal in the Nd:YAG (1064nm) beam path, doubling the frequency (and halving the wavelength) from invisible near-infrared to visible green, which corresponds to another oxyhemoglobin absorption peak--albeit one with slightly higher melanin absorption as well. Two forms of KTP laser are available: an older version with continuous laser output at higher energies than the tunable dye or copper vapor lasers, and a newer Q-switched Nd:YAG laser which delivers a pulsed output at up to 10Hz repetition rates, and with megawatt power-nanosecond duration pulses. The older KTP laser can be mated to a scanner (discussed below) that allows treatment of larger areas with minimal inadvertent overlap thermal damage to the skin, and with shutter durations as low as 10-20 msec. The Q-switched Nd:YAG laser utilizes such high energies at such brief shutter durations that the absorbing chromophore actually is vaporized in a photoacoustic plasma formation, destroying the chromophore and its encasing vessel. Depth of injury is no deeper than 1mm, but the overlying epidermis is often blistered. Careful wound care minimizes any scar potential, which is higher that that seen with the yellow light lasers, but still much less than seen with the argon laser. The photoacoustic ablation of abnormal vessels is sufficiently different from selective photothermolysis seen with the pulsed dye lasers, and may provide another treatment option in the patient responding poorly to pulsed dye laser therapy (because of high-flow lesions or larger vessel size) or because of scarring from other forms of treatment. No scanner is used with the Q-switched Nd:YAG laser, which has spot sizes up to 3mm; this laser system can also be used for the removal of decorative tattoos at both the 532nm and 1064nm wavelengths.

SCANNERS
A simple hand-held computerized laser delivery system (Hexascanner) already exists that can be mated to the fiberoptic output of the tunable dye, copper vapor, or KTP laser to allow treatment of large areas. Since the maximum usable spot size for these lower-power lasers is 1mm, spot-by-spot treatment of large areas is tedious and imprecise without some sort of mechanical "scanner" delivery system to avoid overlaps and gaps between such tiny laser impacts. This scanner allows treatment of up to 13mm diameter hexagonal areas containing 127 precisely-placed 1mm spots, and may allow better treatment of port-wine stains with these two yellow light lasers. This type of scanner was originally developed in Europe for use with argon lasers to allow higher energy densities in the small 1mm spot size, thereby preventing exposure times significantly longer than the thermal relaxation times of the treated microvasculature and the resultant nonspecific thermal damage. Now applied to the lower power output continuous-wave tunable dye and copper vapor lasers, this scanner may combine the advantages of slightly longer beam durations, yellow wavelength specificity, and easy ability to treat 13mm hexagonal "spots" in large port-wine stains whose treatment would have been extremely tedious using individually-fired 1mm spots. The somewhat higher power of the KTP laser allow shutter durations very close to the upper end of thermal relaxation times for port wine stain-size vessels (10msec), as opposed to the 0.45msec pulse duration of the pulsed dye laser. This may allow better treatment for adult port wine stain patients with larger vessels, or in those already developing vascular blebs or skin thickening. A different scanner has been developed by the copper vapor laser manufacturer, and allows selectable spot density and dwell time in the scanner mode, increasing flexibility over the fixed parameters used in the previous scanner.

LONG-PULSE LASERS; DYNAMIC COOLING OR "CHILL TIPS"
Newer variations on present laser themes include the use of chilled tip, long-pulse (up to 20 or even 100 milliseconds) KTP lasers, long-pulse Nd:YAG (1064nm) lasers, and attachments to pulsed-dye or other vascular lasers that chill and protect the skin overlying the vascular target. A pulsed dye laser utilizing a pulse duration of 1.5msec (1500µsec) and a wavelength of 595nm instead of 585nm (Vbeam™) allows slightly deeper penetration of ablative energy, and successful sealing of larger or higher-flow vessels. This involves more energy and thermal input into the skin, and therefore requires dynamic cooling spray with each laser pulse. These dynamic cooling devices are attached to the laser handpiece, and may allow more effective treatment of deeper, higher-flow, or resistant port wine stains with higher laser fluences, yet with acceptably low risk of overlying skin damage. Higher energy or longer pulse duration would normally increase the resultant scar rate, making these parameters inappropriate for use. However, the dynamic cooling devices chill the overlying skin briefly enough to protect it, while allowing the laser energy to pass through and seal the underlying vessel, providing even more versatility in treatment of "resistant" port wine stains or other vascular abnormalities. Other long(er) pulse lasers with or without dynamic cooling are available to provide more options for the thicker, higher-flow, or "resistant" vascular lesion.

AUSTRALIAN TECHNIQUE
Another treatment method makes use of small laser spot sizes and low power to individually trace out each of the abnormal port-wine vessels or cutaneous telangiectasias under magnification. This is called the Australian technique, where it was first developed and popularized. Though only small areas can be treated at each session due to the precision needed and the tedious nature of this technique, excellent results are achievable with very low scar rates (typically less than 2% overall). This technique allows comparable results to pulsed dye laser treatment. Either the copper vapor or tunable dye laser can be utilized with low power and small spot size, but this technique requires much operator experience and a long learning curve. The Australian technique has not been utilized by large numbers of laser experts, but remains a useful option for those operators experienced in its use.

TREATMENT GUIDELINES
Irrespective of the yellow light laser chosen, multiple treatment sessions are necessary for maximum vessel ablation, usually at intervals no more rapid than every two months. Some vascular lesions may require treatment every four weeks, but port-wine capillary malformations can be safely treated every eight weeks without cumulative skin damage. An occasional treatment at six or seven weeks following the previous does not seem to be harmful, but consistent six-week-interval treatments can cause higher scar rates. Since melanin does absorb some of the laser energy at 577nm or 585nm, thermal skin blistering can occur, and careful post-treatment care is essential to avoid scarring. Antibiotic ointment is used until any blistering is healed, and avoidance of prolonged ultraviolet exposure or use of a sunscreen with SPF 15 or higher is essential to avoid melanin stimulation. With appropriate precautions, congenital capillary malformations (port-wine variety) of the eyelids, lips, and extremities can be as safely and effectively treated as the face, though extremities can respond more slowly and require more time between treatments. Thus far, treatment of huge body areas such as an entire trunk, entire leg, or half of a body surface area is not recommended, since 3-10 treatment sessions (and occasionally as many as 20 or 30) can be necessary for any anatomic area. A hemifacial birthmark can require one hour of treatment and 1000 or more pulses of laser light (depending on spot size). Larger areas require even more time and pulses, making the treatment of huge areas more than most patients, physicians, and laser centers are physically and economically capable of handling.

With the multiple types of yellow (and other wavelength) laser now available to the clinician, treatment of cutaneous vascular lesions has clearly become much more effective than any prior method, and with unprecedented safety. Scarring is no longer a major concern, as scar rates of less than 5% are now possible, but rather determining which technology most effectively deals with the myriad variations in vascular lesions. This new laser technology has given us the ability to treat infants and children with port-wine stains or other non-bulky vascular deformities that heretofore would have waited until adulthood for treatment.

While treatment of port wine stains with any of these types of yellow light laser is uncomfortable (many adults indicate each firing of the laser is similar to the sensation of hot bacon grease splattering on the skin), several hundred or thousand pulses of laser energy may be needed to treat the involved area, and patients under the age of 13 or 14 generally do best with sedation or a mild anesthetic during treatment. Since multiple treatment sessions (usually no more rapidly than every two months) are necessary for maximum birthmark ablation, this also enhances the ability to convince the child to undergo additional treatments, as he or she remembers no treatment discomfort. Post-treatment discomfort is quite mild--much like a sunburn in most patients--and most patients have little swelling in treated areas. Some adults require no anesthesia whatsoever, but most prefer oral Tylenol with codeine and/or Valium to ease the discomfort of treatment. Eyelids, lips, and ears can also be safely treated, though these areas are more sensitive; special eye protection (scleral contact lens) is required when treating the eyelid. Studies are underway to evaluate the effectiveness of EMLA (eutectic mixture of local anesthetic) cream in treatment of some of these lesions, and whether or not any biphasic vascular response to the EMLA cream interferes with the laser's effectiveness.

With each pulsed dye laser treatment, an intense blue-black purpura (bruise) is seen for 7-10 days, gradually resorbing through a stage of color changes similar to a black eye getting better. Tunable dye or copper vapor lasers cause occasional mild bruising and commonly cause blanching or skin blistering which takes several days of careful skin care and antibiotic ointment application to heal. The long-pulse lasers with dynamic cooling have less bruising, but may have a slightly higher risk of scarring due to increased energies being used.

TREATMENT OF HEMANGIOMAS
With this range of laser techniques and technology now available, we may now be able to treat certain types of hemangiomas while still in the small, macular, pink stage prior to the enlargement and progression phase that is so disfiguring, growth-distorting, and potentially permanently scarring. No longer should parents be told "It will (or may) go away; just watch it for now." Parents then watch as these hemangiomas turn their beautiful (and otherwise normal) babies into a child to be stared at and teased at school, all while waiting years for the hemangioma "to go away." Laser treatment while still a "thin" vascular lesion (since the yellow wavelength only penetrates 1.0 - 1.5mm at most)32 may prevent the enlargement and progression phase, or it may simply normalize the upper 1.0 - 1.5mm of the skin. This would still be a significant advantage, as any deeper hemangioma elements could be ablated by subsequent steroid or injection sclerotherapy, and at least the skin might be spared the scarring, thinning, and atrophy of rapidly progressive hemangioma growth. Depending on the studies cited, about 50 - 70% of hemangiomas spontaneously involute by the age of 8. , , Of these, a proportion will have thinned, scarred, wrinkled, atrophic epithelium overlying a resolved or residual spongy hemangioma, still requiring plastic surgical intervention. Then, of course, there are the 30 - 50% of hemangiomas that do not resolve (possibly because of incorrect classification), as well as the macular "pink birthmark" which turns out to be a port-wine capillary malformation that will never "go away."

This means that over half of these infants will require some sort of eventual surgical intervention. Thus, it is now essential to be much more precise with our diagnoses, or at least to refer for evaluation infants with cutaneous vascular lesions appropriate for laser therapy while they are still macular. Yellow-light laser treatment may well be indicated for most macular vascular lesions, but would exclude any lesion already thicker than 2.0mm or so. It is usually inappropriate and ineffective to treat any large (thick) vascular lesion with any of the yellow light lasers, that is, once it has already enlarged. This is particularly true for the pulsed dye laser, since the 450msec pulse duration will coagulate only small vascular channels--capillaries with size and thermal relaxation times consistent with the laser pulse duration. Larger vascular channels seen with hemangiomas have significantly longer thermal relaxation times, and will not respond to pulsed dye laser therapy. Pulsed dye laser treatment of any larger or bulky vascular lesion (hemangioma) is ineffective and unnecessary because of the physics and physical characteristics noted above, and will only cause superficial blistering, difficult wound care, and possibly scarring-while causing no to minimal result, and frustrating the child's parents to accept correct advice later. Of course, the laser can be set to a high enough energy to cause a nonspecific burn in the vascular lesion, leading to dressing changes and wound care to minimize pain and scarring. If improvement is seen, the laser treatment is given credit, though 50-70% will improve on their own without treatment, as discussed earlier.

STEROID TREATMENT OF HEMANGIOMAS
Intralesional steroids, or if unresponsive, injection sclerotherapy, should be employed in more cases where hemangioma progression and enlargement is already taking place, and not only in cases of deprivation amblyopia, airway, or feeding problems with enlarging hemangiomas. Our experience with these types of cases has resulted in satisfactory induction or acceleration of involution in a majority of steroid-treated cases, with few if any side effects. High-dose steroid treatment should be employed judiciously and expertly, however, to avoid potential side effects of growth inhibition or steroid-induced thinning of non-involved tissues.

Intralesional steroids can be expected to be ineffective in 30-50% of hemangiomas, and incidentally, in all incorrectly classified vascular abnormalities that are actually venous malformations rather than true hemangiomas. After two steroid injections without response, I propose that this vascular lesion is a venous malformation, or a nonresponsive hemangioma, and recommend sclerotherapy utilizing sotradecol (sodium tetradecyl sulfate) 1%. Injection of numerous tiny aliquots (0.05cc) into the vascular spaces within the vascular abnormality, taking care to avoid the overlying skin or surrounding tissues, will successfully induce shrinkage and intralesional scar fibrosis. Multiple sclerotherapy sessions are usually indicated for maximum improvement, and families need to be aware that each session can cause significant swelling for several days-more so than steroid injection. When maximally contracted, the lesion's residual vascularity will be reduced significantly, allowing surgical resection and reconstruction as appropriate. This entire course of treatment should be completed before the child enters kindergarten. The course of treatment most traditionally prescribed is to watch and wait for the "hemangioma" to "go away" on its own, and this plan of inaction can often run ten years or longer. This is well into the school age of the affected child, and ensures that if surgical intervention is needed (and it is in over 50% of individuals), it will occur only after the child has already endured years of deformity that could have been prevented.

SPIDER VEIN TREATMENT-LASER vs. SCLEROTHERAPY
Laser treatment of lower extremity varicosities (spider veins) has been very disappointing with older laser technology. Even with yellow light laser technology, most workers report poor results when treating leg spiders, though it should be pointed out that most were utilizing flashlamp-pulsed dye lasers. Vessels too small to be reliably and repeatedly cannulated for injection sclerotherapy with a 30-gauge needle (using 2.5x loupe magnification if necessary) may be insignificantly visible for many patients, but are too large for effective treatment with the pulsed dye laser. For those patients still concerned with these tiny spider veins, or with the "telangiectatic mats" resulting from sclerotherapy of adjacent slightly larger vessels, yellow-light laser therapy can be effective. Vessels larger than 1.0mm cannot be effectively treated by any type of laser therapy without potentially causing cutaneous scarring, and pulsed dye laser therapy has essentially no place in the treatment of lower extremity vessels. This is because the 450msec pulse duration of this laser is much too short for the longer thermal relaxation times of vessels above 200 microns (0.2mm) in size. The longer pulse durations of the copper-vapor laser or tunable dye laser cause slightly more thermal damage, which is necessary to photocoagulate vessels of this size. Scarring is seen with increases in thermal energy delivered to leg veins, so laser therapy is appropriate and effective only for a very small minority of very small vessels.

Longer pulse, multiple-wavelength lasers have recently been introduced into the marketplace, and may have a place in the treatment of smaller (<1000 microns, 1mm or less) spider varicosities. FDA approval has also been received for a non-laser broadband light source, the Photoderm VL(also known as IPL-for intense pulsed light), for the treatment of small varicosities. In this latter machine, a variable-duration flash of visible light above a user-selected cutoff filter (515, 550, 570, 590 or 615nm) can be used to treat small spider varicosities, "resistant" port-wine stains, or other cutaneous vascular lesions with longer thermal relaxation times (i.e., larger diameter, or higher flow rate). Each pulse of light covers an 8x34mm "footprint," and can be double or triple pulsed with variable off times between successive pulses, each of which itself can have a specific on-time. Effectiveness of this device is dependent upon the skill of the operator, skin type of the patient, and size of the vascular lesion, and can take two or more treatment sessions for maximum response. The other long-pulse, dynamic cooling device lasers can also effectively treat small spider veins, but require more than one session, as well as increased cost for the technology. My own experience is that laser or IPL will not replace sclerotherapy, but will rather provide other adjuncts useful in the comprehensive treatment of varicosities.

Injection sclerotherapy followed immediately with laser treatment (or vice versa) has been termed combination therapy. Thus far there has been no convincing evidence that combination therapy allows lower sclerosant concentrations to be combined with lower laser energy densities to yield satisfactory results with decreased complications. Although legitimate research is being done in the area of combination therapy, some unscrupulous operators advertise laser leg vein treatment in order to obtain patient consultations for what is perceived as "the latest and the best," when in fact laser therapy is applicable for no more than 10 or 20% of all spider varicosities. Since the patient pays (usually much more than for sclerotherapy alone) for laser leg vein treatment, and since laser alone is ineffective, these physicians perform sclerotherapy (which is effective), telling the patient that this is "opening up" the vessel, or "numbing it up." This "preparation" is usually performed with polidocanol (since it is an anesthetic sclerosant), followed by the laser leg vein treatment, which is done with great fanfare. In this unfortunately questionable scenario, the pre-laser sclerotherapy is quietly done with the same concentrations of polidocanol as when it is used alone, and the laser energy chosen is usually enough to cause a tissue bruise without the laser itself being effective at all. The pulsed dye laser is frequently the one used, since a visible purpura (bruise) can be seen at 3.5 - 4.0 joules/cm2, whereas vein ablation does not even begin until energy fluences of 6.5 - 7.5 joules/cm2 (roughly twice the minimum purpura dose--MPD) are achieved. Thus the laser causes no therapeutic effect but a visible (and ineffective) bruise that allows the unethical physician to charge "laser surgery" prices for what is, in reality, injection sclerotherapy. When challenged, however, "combination therapy" is applied as a defense. Disclosure of exact agents and concentrations of injected medications, and exact type and energy densities of laser, will allow separation of legitimate and ethical use of combination therapy from inappropriate use by physicians seeking to capitalize on the public's fascination with lasers.

Laser treatment of veins that are of a size treatable by injection sclerotherapy generally requires high energy settings that result in skin damage (atrophy or hypopigmented scarring), or low energy settings that allow spider recurrence because of insufficient laser energy delivery. For vessels of this (too big) size, no middle ground exists. Thus, at the present time, laser treatment for leg veins is often inappropriate and can be associated with advertising "hype" rather than ethical and scholarly application. In the near future, newer and better machines may prove this to be an overly dogmatic assertion.