LASERs for vascular lesions. Mashayekhi vahid MD Dermatology Department Emamreza Hospital Mashhad-Iran

Transcription

1 LASERs for vascular lesions Mashayekhi vahid MD Dermatology Department Emamreza Hospital Mashhad-Iran

2 Introduction This technology is new and rapidly evolving, and therefore, guidelines are so far as the technology evolves Guidelines indicating minimum standards of care for lasers on vascular lesions based on the available evidence and need to be reviewed periodically Available vascular lasers are more suitable for western skin types and the parameters used in western skin may not always suit all other skins

3 Introduction Lasers and non-coherent intense pulse light sources (IPL) are based : selective photothermolysis. The target chromophore in vascular lesions is the oxyhemoglobin Oxyhemoglobin has three major absorption peaks at 418, 542, and 577 nm. Optimal absorption is within nm range

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5 Light energy absorbed by oxyhemoglobin Thermal energy selective microvascular damage and thrombosis If the pulse duration is more than the thermal relaxation time (TRT), non-selective thermal damage of perivascular connective tissues occurs leading to tissue destruction and scarring

6 Factors that affect the absorption of laser Vessels size Depth of the lesion Area of body Laser spot size Skin type Fluence

7 Diameter of vessels Vessels with a diameter of μm have TRT of 1-10 ms. Blood vessels with diameter >100 μm have a higher TRT, and therefore, require longer pulse duration.

8 Depth of vessel Superficially located lesions (papillary dermis) are available for standard wavelengths (577, 585 nm) But the deeper vessels will need lasers with longer wavelength (up to 600 nm) for deeper penetration. Important: Consider the deepest part of the vessel and not its closest distance from the epidermis Infrared wavelengths more effective for deeper blue vessels shorter wavelengths more effective for superficial red telangiectasias

9 Site of lesions Leg vessels : deeper and more deoxyhemoglobin absorb the laser light in the nm wavelength spectrum Lesions on face and upper trunk respond better than those in lower trunk and legs % reduction in fluence for Scarring prone areas : anterior chest, neck AND Delicate skin :periorbital region and neck Malformations on the first and third branches of trigeminal nerve respond better than those over the second branch

10 Age of patients Young people respond better than elderly since the blood vessels are smaller and more superficially located

11 Skin type Darker skin types require longer pulses duration, higher fluence, and longer pulse intervals since epidermal melanin absorbs the laser energy

12 Larger spot size Deeper penetration Less total treatment time Spot size more photocoagulation and swelling Smaller spot size result in greater scatter of laser energy not effective for large or deep vessels Important : do not underestimate the dramatic increase of energy delivered to tissues upon increasing spot size. When in doubt, smaller spot sizes are recommended, with manipulation of the fluence to achieve the desired energy at the target level

13 Fluence ( energy per unit area ) Is scheduled based mainly on vessel color, other determinants vessel size, depth, and intravascular pressure spot size Purple and blue vessels absorb more energy than pink and red vessels, and require less fluence Greater intravascular pressure (nose or legs) require higher fluences to achieve effective thermocoagulation A test spot on a small, representative area may be performed initially, before treating the entire lesion.

14 Role of Epidermal cooling Cooling is an integral part of vascular lasers High energy is required to thermocoagulate the vessels located deep in the skin Epidermis should be protected by cooling to minimize the damage to keratinocytes and melanocytes Cooling may reduce the efficacy of lasers by blanching effect on the underlying blood vessels.

15 Classification of Vascular Lasers

16 Applications of the laser types The wavelength peaks of the laser light, pulse durations and how the target skin tissue absorbs this, determine the clinical application

17 Flash-Lamp Pumped Pulse Dye Laser PDL is the most commonly used laser for vascular lesions emits a pulsed beam of yellow light at 585 nm, powered by a flash lamp capable of producing pulse duration of 450 μs TRT of skin vasculature, is μs for vessels with diameter of μm

18 PDL At 585 nm and 450 μs penetrates 0.2 mm below the dermo-epidermal junction can be increased to mm by increasing the wavelength First-generation PDLs with short pulse durations, small spot size, high fluence, and have high complication rates. purpura appears immediately and can last for 7-14 days The other common side effects hyper pigmentation, hypopigmentation, hypertrophic scarring, dermal and epidermal atrophy

19 The more recent PDLs Large spot sizes (elliptical 2 Χ 7 mm) Longer wavelengths (590, 595, and 600 nm) greater depth of penetration Longer pulse durations ( ms) better matching to the feeding vessel's size, each macropulse is subdivided into 6-8 micropulses and greater total fluence can be delivered to tissues in a gentle fashion that mitigate the risk of purpura Epidermal cooling reduce complications and allow safe use of higher fluences

20 Long PDLs Longer pulse duration PDL achieves lower peak energy; heat is more slowly applied to blood vessels and eliminates or minimizes photoacoustic effects to capillary walls less red blood cells leakage, and no purpura, while maintaining clinical efficacy

21 PDL application PDL can be safely used in children and infants Is used mainly for port wine stains and several acquired vascular lesions such as telangiectasia, pyogenic granuloma, venous lake, cherry angioma, and poikiloderma of civatte PDL is difficult to maintain and service

22 Neodymium :Yttrium-Aluminum- Garnet (ND:YAG) Laser Wavelength of 1064 nm Deeper penetration is able to create a coagulation effect at a depth of 5-6 mm Lower absorption by hemoglobin and possible better absorption by deeper blue spider veins than the traditionally used shorter wavelengths (KTP, pulsed dye, IPL, diode)

23 ND:YAG Laser The ratio of melanin to blood absorption is similar at 585 and 1064 nm, whereas the absolute values of absorption and scattering coefficients are considerably lower at 1064 nm The increase in the treatment fluence does not necessarily cause damage to epidermis, because the absolute absorption of melanin is lower at 1064 nm as well

24 ND:YAG Laser application Nd:YAG system should theoretically be able to treat any vascular lesion both superficial and thin or deep and thick through appropriate selection of spot size (3, 5, 7, and 10 mm) pulse duration ( ms) high fluences (up to 300 J/cm 2 ) and optimal cooling systems to avoid pain or burning

25 ND:YAG Laser application Nd:YAG lasers are used to treat Rosacea - Facial telangiectasia, Poikiloderma of Civatte -Hemangiomas of infancy, tuberous hemangiomas, Port wine stains (PWS) - Leg veins The 3 and 5 mm spot sizes are suitable for superficial lesions such as telangiectasias, rosacea, poikiloderma of Civatte, flat hemangiomas The larger 5 or 7 mm spot sizes are needed for thicker or deeper ones such as tuberous hemangiomas or PWS, leg veins

26 ND:YAG Laser application Pulse durations; for thin vessel: ms, for medium vessel: ms for thick vessels: ms. Variable fluences (from 14 to 195 J/cm 2 ) are used

27 Algorithm for the Nd:YAG laser treatment of vascular lesions

28 Intense Pulsed Light a non-coherent light beam with a spectrum of wavelengths from 500 to 1200 nm. Cut-off filters at 515, 550, 570, 590 nm are used for vascular lesions. Computer software provides flexibility in using these devices, not normally available in laser Bigger spot size; hence larger areas can be treated efficiently with less discomfort.

29 Intense Pulsed Light The longer wavelength ; can penetrate deeply Splitting the energy into two or three pulses with different pulse delays skin can be cooled between pulses Rapid divergence of the IPL beam the hand piece must be in contact (or almost in contact) with the skin for effective treatment

30 IPL application Successfully used for the treatment of PWS Leg telangiectasias, Essential telangiectasias, Venous malformations, Poikiloderma of Civatte

31 Treatment parameters for IPL

32 Fractional Photothermolysis Wavelength : 1550 nm targets tissue water Different tissue compartments (e.g., blood vessels, dermal melanin, and sebaceous glands) at various depths of the skin can be targeted water is a large component of blood vessels microthermal zones of injury in the dermis may randomly hits to the dermal vasculature likely that both hypotheses work synergistically This may especially be beneficial for the treatment of Fitzpatrick skin type IV-VI

33 Indications for vascular lasers

34 Absolute: Contraindications for vascular lesions Active local infection Photo-aggravated skin diseases and medical conditions Relative: Unstable vitiligo Psoriasis Keloid and keloidal tendencies Patient on isotretinoin Patient who is not cooperative or has unrealistic expectation

35 Summary of recommendations for use of lasers for vascular lesions

36 after nine 585-nm pulsed dye laser treatments

37 Hemangioma after three 585-nm pulsed dye laser treatments

38 Telangiectasias on the nose and medial cheeks before and after argon-pumped tunable dye laser treatment

39 Telangiectasia on the calf before and after intense pulsed-light treatment

40 Angioma on the frontal hairline before and after Nd:YAG laser

41 Poikiloderma on the neck before and after two 585-nm pulsed dye laser treatments

42 Purpura immediately after pulsed dye laser treatment of facial telangiectasias.

43 با تشکر از توجھ شما

44 Port Wine Stain PDL is the treatment of choice for all age groups and anatomic locations has the best documented safety record clearance rates vary widely ; 70% will lighten by 50% or more, New-generation PDL machines are more effective vessels smaller than μm appear resistant to all kinds of PDL treatment

45 Treating PWS earlier ; Port Wine Stain greater efficacy and decreased recurrence Smaller lesions (<20 cm 2 ) clear better Head and neck lesions respond better Lesions on proximal extremities respond better less responsive ; Centrofacial second branch of trigeminal nerve (V2) region Pink lesions are difficult to lighten than mature red lesions Deep purple and nodular lesions

46 side effect The commonest is hyper pigmentation followed by hypopigmentation, hypertrophic scarring, dermal and epidermal atrophy.

47 PWS & laser treatment Has a non-uniform response to laser treatment Lesions are made of different blood vessels with different depths of involvement Different blood flow rates through vessels The treatment parameters: Pulse duration range ms; usually ms, Delay: ms, spot size: 5-10 mm, Fluence ranging from 4.5 to 8.0 J/cm 2. The number of treatments per lesion ; 2 to 12 or more at 6-8 week intervals. Clinical end points for PDL treatment include Complete lightening Most commonly, failure to lighten any further with subsequent treatment

48 Options for Treatment Resistant PWS Using longer pulse durations for PDL ;ranging from 2 to 40 ms Using pulse stacking (two to three consecutive pulses applied immediately after the preceding pulse to the same spot For purple or blue tinge lesions ; millisecond pulsed 1064-nm Nd:YAG

49 Nd:YAG laser for PWS Histologically, Nd:YAG laser targets PWS vessels much deeper than PDL Nd:YAG lasers can be used to treat PWS with variable spot sizes (3, 5, 7 and 10 mm), highly variable pulse duration ( ms) high fluences (up to 300 J/cm 2 ) Oxyhemoglobin has minimal absorption at 1064 nm wavelength, non-specific tissue destruction should be limited to nodular, hypertrophic lesions, and PDLresistant PWS.

50 IPL for PWS IPL is a useful alternative (to PDL), adjunctive or primary treatment (in deeper component) of PWS. IPL is useful in deep purple and nodular lesions. These lesions have a deeper component that cannot be reached by the PDL, but can be reached by IPL or Nd:YAG. All IPL systems are not equally effective. Destruction of residual variable diameter and deeper ectatic dermal capillaries of PWS with IPL wider spectrum of wavelengths, high fluences, greater cumulative capillary heating with the multipulse mode

51 Continuous wave CO 2 laser Good results for the treatment of nodules and hypertrophy in PWS. CO 2 laser resurfacing for adults with refractory Early PWS in children should be treated with nonablative lasers such as PDL.

52 PDL resistant PWS Dual 595/1064-nm wavelength laser Sequential PDL/Nd:YAG laser treatment for PWSs, significant improvement while using fluences lower than those used for either laser alone. Some PWS can recur years after treatment

53 Hemangioma Laser treatment of hemangioma remains controversial Laser therapy for hemangiomas is considered: Potential for functional impairment. Risk of ulceration, rapid enlargement, recurrent trauma, moist area Cosmetic disfigurement. Residual telangiectasia after complete involution PDL has the best documented safety record No age restrictions are placed, even safely for premature infants Beneficial effects are limited to the superficial portions (depth of vascular injury ;1-2 mm). will not reduce the growth of deeper component

54 PDL for Hemangioma optimal parameters are Wavelength of nm, fluence of J/cm 2, pulse duration: μs, spot size 5-7 mm and concomitant cooling device

55 PDL for Hemangioma No significant benefit in early uncomplicated hemangioma, The complications are atrophic scarring, ulceration, hemorrhage, pain and residual scarring. Long pulsed PDL has been reported to be safer and more effective for childhood hemangioma

56 Nd:YAG laser for PDL for Hemangioma For the deep components Variable results Nd:YAG laser has a narrow band of safety and efficacy Carries the risk of scarring, blistering, crusting, pigmentation and textural abnormalities. These complications are due to deep thermal injury from intensely penetrating near infrared light.

57 Facial Telangiectasia PDL and IPL have been widely used for facial telangiectasia. post-treatment purpura after PDL is cosmetically unacceptable. Purpura-free long pulsed PDL has shown good efficacy. Purpura-level treatments have a distinct advantage for treating thicker telangiectasia

58 Long pulsed dye laser for facial telaniectasia The optimal parameters for LPDL are 7-10 mm spot size, 6-20 ms pulse width, 7-12 J/cm 2 fluence, two to three passes,

59 IPL for facial telaniectasia 87% of patients presented a clearance of % with 1-2 IPL sessions. For large veins triple pulse mode 590 nm cut-off filter pulse times of 2.4, 3.0, and 3.5 ms, delay of 30 and 25 ms and for red fine telangiectasia, and spider lesions double pulse mode 570 nm cut-off filter pulse times of 4.0 ms, delay of 30 ms Perilesional erythema, blanching, or vessel clearance are the optimal treatment endpoints.

60 Facial telaniectasia, laser treatment LPDL is superior to IPL due to superior efficacy and less treatment-related pain IPL-system with a cooling device, might have resulted in a better efficacy. A small spot size (1.5 mm) Nd:YAG laser using a pulse width of 20 ms or higher is another modality

61 Facial telaniectasia, treatment limitations post-treatment purpura after PDL is cosmetically unacceptable inferior results in purpura-free treatments IPL has the side effect of significant erythema and edema. Nd:YAG laser broad range of vessel diameters but relatively poor absorption by hemoglobin In darker skin risk of post-treatment pigmentation

62 Rosacea Associated Telangiectasia and Erythema Long pulse duration, 595 nm, PDL is safe and effective for treating rosacea minimal side effects and no long-term complications. PDL in short pulse duration; immediate posttreatment purpura, pigmentation and atrophic scarring, resolved after few months Two separate settings enabled optimal treatment of linear vessels and diffuse erythema: 3 ms pulse duration for diffuse erythema 40 ms for linear telangiectasia

63 PDL for Rosacea Purpura-free removal with pulse-durations of 6 and 10 ms The drawback to purpura-free PDL: the lack of obvious visible end points excessive overlapping might increase scarring Treatment with the PDL improve the telangiectasias and erythema, the symptoms associated with rosacea other signs of photodamage due to inflammation

64 PDL parameters for Rosacea Wavelength :595-nm spot size:10-mm, pulse duration:6-ms, Fluence: 7 J/cm 2 from 0.5 to >7J/cm 2 to achieve a transient purpura lasting for less than 3 s cryogen cooling (30-ms spray administered 20 ms before the laser firing)

65 IPL for Rosacea Is safe and effective reduces erythema and telangiectasia with minimal unwanted effects. Treated patients with with one to seven IPL sessions: 83%had reduced redness, 75% reduced flushing and improved skin texture, less than 1% recurrence 64% noted fewer acneiform breakouts

66 IPL for Rosacea IPL parameters are spectrum ranging from Wavelength 515 to 1200 nm Pulse durations between 2 and 6 ms, Single or multiple pulse mode 15-ms pulse delay A randomized, controlled, single-blind, split-face trial ; IPL and PDL performed with similar efficacy and safety, and both are reasonable choices for the treatment of rosacea

67 Poikiloderma of Civatte Requires wavelengths that are absorbed concurrently by two different chromophores, namely hemoglobin and melanin The ectatic vessels around 0.1 mm in diameter reside in the papillary dermis contain mostly oxyhemoglobin that absorbs light at 418, 542, and 577 nm. Melanin concentrated basal epidermis, absorbs light continuously over a broad spectrum

68 laser for Poikiloderma of Civatte Complete clearing is difficult to achieve Multiple sessions are usually necessary to obtain optimal clearing The newer generation pulsed dye lasers with wavelength of 595 nm pulse duration of 1.5 ms with cryogen spray cooling produce optimal clearing Optimal outcomes are achieved using a 10 mm spot size with lower fluences

69 laser for Poikiloderma of Civatte Fractional photothermolysis efficacy, safety and optimial treatment parameters need to better elucidated IPL has been utilized with good results. With IPL, the target is vascular, epidermal, and dermal melanin due to the broad band of wavelengths. The near-infrared component of IPL improve skin texture and reversal of the cutaneous atrophy typically associated with poikiloderma of Civatte

70 IPL parameters for poikiloderma Three sessions of Wavelength of 515 nm filter, single pulse 3 ms/double pulse of 2.4 and 4 ms (10 ms delay between the pulses) fluences from 25 to 42 J/cm 2 significant reduction of 75%-100% Adverse effects were minimal and transient erythema, rare short-term purpura, and rare crusting

71 laser for Poikiloderma of Civatte The skin of the neck is thin and there is greater risk of atrophy and hypopigmentation Optimal results can be achieved with using both IPL and PDL Adverse effects are minimized with the use of larger diameter spot sizes, lower fluences, non-overlapping pulses, and repetitive treatments

72 laser for Pyogenic Granuloma PDL is a safe, effective, and reasonable alternative to conventional therapy. Safe for small pyogenic granulomas in children Lesions that were raised more than 5 mm from the surface did not respond to the PDL Coagulation, retraction or shrinkage of the lesion is the end point

73 laser for Pyogenic Granuloma The CW carbon dioxide (CO 2 ) laser has proved to be an effective treatment option Larger lesions can be effectively treated Can treat difficult to access regions and Lesions which bleeds heavily, non-specific coagulation may lead to scars.

74 Combined Continuous-wave/pulsed CO 2 laser first continuous mode (power, 15 W; focused hand piece with variable spot size of mm) and then pulsed mode (pulse length: ms, fluence: 500 mj/pulse with the same hand piece )

75 Venous Lakes The long-pulsed Nd:YAG laser is effective 94% clearance has been reported single treatment depending on the size of lesion 3-mm spot at 250 J/cm 2 5-mm spot at J/cm 2 Clinical end points hardening of the lesion, central blackening, minimal whitening of the periphery, and in most cases, an audible popping sound

76 Venous Lakes The PDL can be used to treat venous lakes with multiple overlapping pulses. Carbon dioxide laser is a good and safe method with single session of treatment using first pass: continuous and defocused mode of 5 W/cm 2, in the second pass: continuous focused mode with the same power density

77 Venous Lakes Multi wavelength laser (595 nm; 1064 nm) are safe, fast, and effective option 595-nm pulsed-dye laser at 20 ms and 10 J/cm 2, followed by 1064-nm laser at 20 ms and 70 J/cm 2.

78 Cherry Angioma PDL is the preferred method Nd:YAG and IPL have been tried Can be treated with simpler treatments such as cryosurgery, and radiofrequency, which are cheaper and easily available.

79 Leg Veins Are difficult to treat by laser Because have ; increased hydrostatic pressure a thick surrounding adventitial tissue increased basal lamina association with venous disorders reduced amount of oxyhemoglobin

80 laser for Leg Veins To thermocoagulate the deeper vessels should be able to deliver very high energy pulses through large spot sizes to enhance scattering into dermis Should be considered as an alternative to sclerotherapy in patients with needle phobia, who tolerate sclerotherapy, who fail to respond to sclerotherapy, who had developed adverse effects from sclerotherapy, and who are prone to telangiectatic matting

81 laser for Leg Veins Lasers enable treatment of the following: Spider veins: mm red and blue vascular ectasias, often associated with large reticular veins. Reticular veins: non-bulging subcutaneous veins ranging up to 5 mm in diameter. Telangiectasias: mm, residing about 300 μm below the skin surface, from dark blue to bright red. Nd:YAG laser systems are the lasers of choice for leg vein treatment

82 Nd:YAG laser parameters for Leg Veins Spot sizes of 3 and 5 mm for superficial lesions such as telangiectasias, Spot sizes of 5 or 7 mm for thicker or deeper veins. Pulse durations are selected according to vessel size ms for thin, ms for medium, and ms for thick vessels ms or longer for spider veins, reticular veins and leg telangiectasia Variable fluences (from 14 to 195 J/cm 2 ) are used. Overlapping of the treated area is not necessary and the pulses can be spaced 1 mm apart Is painful; therefore, cooling and either topical anesthesia or local anesthesia are necessary

83 Nd:YAG laser parameters for Leg Veins In the direct-contact method, minimal pressure is placed for larger reticular veins slight pressure may be used to minimize the total diameter of the vein to allow greater penetration less total heat accumulation by reducing target size. This also may make the treatment slightly less painful.

84 Other lasers for Leg veins Long-pulsed PDLs to clear vessels less than 0.5 mm. vessels mm, also improveme,not completely For type V skin leg veins, the 1064 nm wavelength is very safe. For type IV and marginally for type V skin; the 810 nm diode at super-long pulse widths of ms is very safe, The 755 nm alexandrite is limited to non-tanned type I-III skin. Leg veins of <1 mm diameter respond better to IPL.

85 lasers for Leg veins The clinical end point is the darkening of the targeted vessel and loss of vessel margins. Blanching of skin should be avoided. Hyperpigmentation is common A drawback to laser therapy and sclerotherapy is that the usual underlying cause of spider veins, incompetence of a large underlying vein, is not treated. Simultaneous treatment of larger veins with longer wavelengths and pulse durations AND smaller veins with shorter wavelengths and pulse durations provide comparable outcomes to treating patches of heterogeneous vessels by sclerotherapy

86 Complications of Laser Treatment for Vascular Lesions 1. Pain: may be a marker for the subsequent adverse effect. 2. Edema: Some is expected at and around the treated site immediately. Periorbital and neck are more prone for edema. Usually the edema subsides by 5-7 days. Appropriate cooling during and after is helpful 3. Bleeding: high fluence and short pulse duration 4. Purpura: Immediately after the treatment and usually fades by 7-10 days.

87 Complications 5. Blistering and discoloration are seen rarely. usually caused by over treatment. Post-inflammatory hypo/hyper pigmentation may result following blistering reduces blistering:» Starting with a test patch,» appropriate parameter selection» proper cooling

88 Complications Hyperpigmentation» more commonly in darker skin» fades in 3-6 months time.» Topical bleaching creams» Hydroquinone topical application 2 weeks prior to the laser session reduces the incidence of hyperpigmentation. Hypopigmentation usually gets corrected in 3-6 months time. 6. Skin texture changes are caused by over treatment (due to excessive fluences or pulse stacking)

89 Complications 7. Scarring: Usually due to over treatment or following disruption of skin surface. Following the pre- and post-laser treatment care strictly reduces the chance of scarring. 8. Reactivation of herpes: oral Prophylaxy is recommended for patients with history of herpes, particularly while treating lesions on face 9. Infection: is uncommon; edema, erythema, pain, oozing, crusting and fever indicates infection. Topical and systemic antibiotics should be used.

90 Complications 10. Nonresponders: some lesions do not respond despite the adequate treatment. This possibility should be informed to patients prior to treatment and proper pretreatment counseling is recommended in all cases.

91 Prelaser Treatment Care Detailed pretreatment education should be done to the patients with information sheets and brochures. Informed consent is a must in all cases Photography, preoperatively at each session is required in all case. Patients medical history should be analyzed for any contraindications for laser treatment. Topical bleaching creams for dark skinned individuals at least 2 weeks prior to the laser treatment. A broad-spectrum sunscreen at least 4 weeks prior to the treatment session. Test treatment on a representative area may be performed Adequate eye protection goggles are necessary for all persons in the laser room. For treating lesions on the eye lids, corneal shields are a must to protect the eye. Patients data should be recorded in a separate log which includes, fluence used, site of lesion, wavelength used, total number of pulses and any untoward response during the treatment.

92 Postlaser Treatment Care Adequate cooling post laser treatment with ice packs on larger areas. Patients should be asked to sleep with extra pillow to encourage the gravitational removal of inflammatory fluid, for treating lesions around the eye. Patients should be instructed to use a broad-spectrum sunscreen post laser treatment. Patients should be instructed not to pick or scratch the treated sites. Topical antibiotics in a cream or ointment base are prescribed for the treated site to prevent infection. Patient is advised to use mild non-irritating soaps on the treated site. Mild cosmetics may be used after laser, except in cases of blistering. Patients should avoid swimming and contact sports during healing time.

93 Choice of lasers in PWS

94 Summary of recommendations for use of lasers for vascular lesions