Part 2: Treatment Methods and Favorable Machines Used - Port-wine Stains
How are port-wine stains treated? What is the most favorable form and device for treatment?
Physicians have tried a series of treatments for Port-wine stains, including radiation (laser treatment such as PDL or 532 nm KTP laser beams), tattooing (I’m just as surprised), freezing (the skin cells are literally frozen and destroyed using an extremely cold liquid or instrument; the technique is known as cryotherapy or cryosurgery), dermabrasion (or surgical skin planing, it is a procedure in which the skin is frozen and then a specialized instrument is used to "sand" the skin), and sclerotherapy (a procedure that involves the injection of a chemical irritant into a vein to sclerose or "harden" it). The only therapy procedure that does not cause damage to the rest of the skin while destroying the skin’s capillaries is laser treatment (PDL and KTP alike).
Pulsed dye laser (PDL) is a vascular laser (i.e. laser that targets blood and vein-caused imperfections). It uses yellow light wavelengths (585-600nm) that selectively target both oxyhemoglobin (hemoglobin that is bound to oxygen O2, where hemoglobin is a protein found in red blood cells or RBCs and is responsible for transporting O2) and deoxyhemoglobin (hemoglobin that is not bound to O2). The latter procedure is known as photothermolysis (“photos” is Greek for light, “thermo” is Greek for heat, and “lysis” is Greek for separate or breaking down of cell). PDLs penetrate up to 2 mm in the skin. Newborns and young children, who have thinner skin, tend to respond well to this type of laser; the response in thicker and darker lesions may be lower.
Despite the fact that PDL is a wide form of treatment, some studies (“Treatment of port wine stains with the pulse dye laser” published in “Annals of Plastic Surgery”, Vol. 56, Ed. 4, pages 460-463, April 2006 and “Treatment of port wine stains using the pulsed-dye laser at 585 nm with the dynamic cooling device”, Vol. 2, Ed. 1, pages 33-36, March 2000) and customer feedbacks reveal that treatment with first generation PDL can sometimes be ineffective (when treatment is commenced at older ages at which the port-wine stain has become darker or when the port-wine stain is hypertrophic i.e. excessively accumulated) where they are unable to remove every vascular lesion entirely (just make them less obvious). Also, PDL can cause skin bruising which should lessen on the longer run.
PDL is not meant for tan, olive, or brown skin (Fitzpatrick type IV, V or VI respectively) as it highly causes pigment changes, namely discoloration. Naturally, PDL is not meant for women who are pregnant or breast-feeding.
Another form of PDL called the flashlamp-pumped pulsed dye laser or FPDL has shown significant improvement in treating port-wine stains for infants and young children. This is because FPDL emits 577-585 nm laser beams at a pulse duration (exposure time per pulse) of 450 μs to 1.5 ms; this limits the destruction of skin cells and heat dissipation to the targeted vasculature without causing damage to the surrounding structures in the epidermis or dermis (layman terms: it destroys only the hemoglobin in vein cells that need destruction without affecting surrounding skin cells and structures). Furthermore, second generation PDLs and FPDLs employ longer wavelengths, higher fluences (radiation dose), longer pulse widths (lower frequencies), and using dynamic cooling devices (DCD). DCD allows the application of higher fluences while reducing the risk of epidermal damage. However, like PDL, FPDL can be ineffective for people older than 6 years.
The amount of fluence needed, the amount of treatment sessions, and the cost of treatment sessions rely on a) the dermatologist’s assessment of the thickness and severeness of the port-wine stain b) the center’s equipment c) the dermatologist’s fees. On average, treatment sessions can cost 300$ to 2000$. For infants and young children (less than 10 years old), the 90-95% of the port-wine stain is treated (almost 100% of patients). For other age ranges, 80% of patients can have 90-95% of the stain treated while others can have up to 70% of the stain treated.
The most renowned machine used for PDL treatment is the Candela V-Beam Perfecta. It’s the most reliable and the DCD system is very good for pain relief.
Another form of port-wine stain treatment is Q-switched laser such as KTP laser and Nd:YAG laser treatment. As mentioned before:
1-
KTP laser: a beam generated by a neodymium:YAG i.e. Nd:YAG laser is directed through a potassium titanyl phosphate crystal to produce a beam in the green visible spectrum; used for photoablation and photocoagulation. The wavelength of KTP laser beams is 532 nm, meaning that more heat will be absorbed by the targeted hemoglobin than other chromophores such as melanin (protein whose presence determines skin color). The 532 nm KTP laser allows higher selectivity in photothermolysis. In analyzing the choice between 532 nm and the 585 or 595 nm PDL wavelengths, there will be higher melanin absorption at 532 nm. However, 532 nm also has a higher hemoglobin absorption coefficient, with the result that the selectivity between hemoglobin and melanin is actually better at 532 nm. This better selectivity at 532 nm means there is a greater range between the fluence for effective treatments and the fluence for epidermal damage when compared to the PDL wavelengths, improving the safety profile for treatments. Also, for PDL resistant port-wine stains, the KTP laser treatment shows better improvement for lightening of stain.
2-
neodymium:yttrium-aluminum-garnet (Nd:YAG) laser: a laser whose active medium is a crystal of yttrium, aluminum, and garnet doped with neodymium ions, and whose beam is in the near infrared spectrum at 1060 nm; used for photocoagulation and photoablation. The Nd:YAG laser beams are only used to treat extremely hypertrophic port-wine stains (deep vascular condition).
The latest machines for KTP and Nd:YAG laser treatments is the Cutera Excel V:
The Cutera has a mode that dispenses 532 nm KTP laser beams and 2 modes that are capable of dispensing Nd:YAG laser beams up to 1064 nm. Plus, it’s equipped with a patented hand-piece that allows better visibility of treatment area, adjustment of spot size (again, better focus on treatment area i.e. target vessel), and continuous contact cooling (better visibility and patient protection especially epidermis).
Finally, IPL or intense pulsed light laser treatment: one of the worst options around, just forget about it (around 40% lower treatment response compared to FPDL and KTP laser treatments).
