Cutaneous vascular lesions are common in both children and adults. The vast majority of these lesions respond well to laser treatment. A select few lesions may require surgical intervention. In order to choose the optimal laser treatment for a given lesion, it is important to have a thorough understanding of the available technology. This understanding includes the characteristics of each laser wavelength, pulse duration, and possible associated epidermal cooling. Furthermore, it is important to understand the specific characteristics of each individual vascular lesion. Together, laser treatment of cutaneous vascular lesions of the head and neck region can be optimized.
The history of vascular lesions has origins in a variety of cultures, including ancient Greece, Rome, and Europe. Many vascular lesions are present in infancy, whereas other vascular lesions appear later in life. The latter group of vascular lesions includes, but is not limited to, telangiectasias, spider angiomas, pyogenic granulomas, and angiofibromas. The cutaneous vascular lesions that are present in infancy include vascular malformations and hemangiomas. These lesions are frequently called birthmarks. This term can imply a cause-and-effect relationship between a mother’s behavior, cravings, or aversions, and the child’s cutaneous lesion. This incorrect concept is referred to as maternal impression and has been present throughout the evolution of the understanding of these lesions.
Pediatric vascular lesions
A child with a facial vascular lesion may be at a distinct disadvantage in terms of social, professional, and economic potential. Few prominent historical figures have had cutaneous vascular tumors or malformations. These figures include Marcus Tullius Cicero (106–43 bc ), a Roman orator, and James II of Scotland (1403–1460), also known as James of the fiery face. James II of Scotland was depicted in one portrait as having what appears to be a hemifacial port-wine stain.
A more recent historical figure to have a vascular malformation is Mikhail Gorbachev. The negative connotation associated with these lesions persists today, as pictures of Mr Gorbachev show. A review of 200 consecutive 1985 issues of Pravda (a leading newspaper of the Soviet Union and an official organ of the Central Committee of the Communist Party between 1912 and 1991) revealed that, in 24 pictures in which the vascular mark would be expected to show, it could not be discerned. The pictures are believed to have been air brushed to eliminate the appearance of the vascular malformation.
This persistent misconception regarding vascular cutaneous lesions serves as a compelling inspiration for physicians to understand the classification of these lesions, the rationale for laser therapy, the various lasers available, and their respective strengths and weaknesses, and to use the information in treating patients with these lesions.
Classification of vascular cutaneous lesions
Vascular anomalies most frequently present at birth or in early childhood, and the craniofacial region is the most common site of involvement. Pediatric vascular anomalies can be divided into 2 broad categories: vascular tumors and vascular malformations. First highlighted by Mulliken and Glowacki in 1982, this biologic classification is based on differences in natural history, cellular turnover, and histology. In 1996, an updated classification was introduced by the International Society for the Study of Vascular Anomalies (ISSVA), which simplified and further categorized vascular tumors and malformations. Vascular tumors include idiopathic hemangiomas (IH); congenital hemangiomas, including noninvoluting and rapidly involuting variants dubbed noninvoluting congenital hemangiomas (NICH) and rapidly involuting congenital hemangiomas (RICH), respectively; as well as kaposiform hemangioendotheliomas and tufted angiomas. Vascular malformations can be further subdivided into low-flow lesions (capillary, lymphatic, and venous malformations) and high-flow lesions (arteriovenous malformations and arteriovenous fistulae). Mixed lesions are common ( Table 1 ).
| Vascular Tumors | Vascular Malformations | ||
|---|---|---|---|
| Infantile hemangioma | Superficial Deep Mixed | Low flow | Capillary Venous Lymphatic |
| Congenital hemangioma | RICH | High flow | Arteriovenous malformation |
| NICH | — | Arteriovenous fistula | |
| Kaposiform hemangioendothelioma | ± Kasabach-Merritt phenomenon | Combined | Capillary-lymphatic-venous (Klippel-Trenaunay) |
| Tufted angioma | ± Kasabach-Merritt phenomenon | — | Capillary-venous (mild eases of Klippel-Trenaunay) |
| Pyogenic granuloma | — | — | Capillary-venous with arteriovenous shunting (Parkes-Weber syndrome) |
| Spindle cell hemangioendothelioma | — | — | Capillary-arteriovenous malformation |
| More rare hemangioendotheliomas (eg, Dabska tumor, lymphangioendotheliomatosis) | — | — | Arteriovenous malformation-lymphatic malformation |
This article focuses on 4 specific types of vascular tumors/malformations that are amenable to laser therapy: (1) infantile hemangiomas, (2) capillary malformations, (3) venous malformations, and (4) lymphatic malformations.
Classification of vascular cutaneous lesions
Vascular anomalies most frequently present at birth or in early childhood, and the craniofacial region is the most common site of involvement. Pediatric vascular anomalies can be divided into 2 broad categories: vascular tumors and vascular malformations. First highlighted by Mulliken and Glowacki in 1982, this biologic classification is based on differences in natural history, cellular turnover, and histology. In 1996, an updated classification was introduced by the International Society for the Study of Vascular Anomalies (ISSVA), which simplified and further categorized vascular tumors and malformations. Vascular tumors include idiopathic hemangiomas (IH); congenital hemangiomas, including noninvoluting and rapidly involuting variants dubbed noninvoluting congenital hemangiomas (NICH) and rapidly involuting congenital hemangiomas (RICH), respectively; as well as kaposiform hemangioendotheliomas and tufted angiomas. Vascular malformations can be further subdivided into low-flow lesions (capillary, lymphatic, and venous malformations) and high-flow lesions (arteriovenous malformations and arteriovenous fistulae). Mixed lesions are common ( Table 1 ).
| Vascular Tumors | Vascular Malformations | ||
|---|---|---|---|
| Infantile hemangioma | Superficial Deep Mixed | Low flow | Capillary Venous Lymphatic |
| Congenital hemangioma | RICH | High flow | Arteriovenous malformation |
| NICH | — | Arteriovenous fistula | |
| Kaposiform hemangioendothelioma | ± Kasabach-Merritt phenomenon | Combined | Capillary-lymphatic-venous (Klippel-Trenaunay) |
| Tufted angioma | ± Kasabach-Merritt phenomenon | — | Capillary-venous (mild eases of Klippel-Trenaunay) |
| Pyogenic granuloma | — | — | Capillary-venous with arteriovenous shunting (Parkes-Weber syndrome) |
| Spindle cell hemangioendothelioma | — | — | Capillary-arteriovenous malformation |
| More rare hemangioendotheliomas (eg, Dabska tumor, lymphangioendotheliomatosis) | — | — | Arteriovenous malformation-lymphatic malformation |
This article focuses on 4 specific types of vascular tumors/malformations that are amenable to laser therapy: (1) infantile hemangiomas, (2) capillary malformations, (3) venous malformations, and (4) lymphatic malformations.
Treatment options
Treatment options for pediatric vascular cutaneous lesions include both laser and nonlaser techniques. Nonlaser methods include watchful waiting and allowance of time for involution (infantile hemangiomas), ligation and excision, artificial ulceration, electrolysis and thermal cautery, sclerosant therapy, radiation, steroids (local injection or systemic administration), chemotherapy, embolic therapy, and, most recently, systemic therapy with β-blockers. This article focuses on laser treatment options, but this modality is just one part of an otolaryngologist’s armamentarium in treating pediatric vascular lesions.
This article is presented in 2 parts: (1) a discussion of specific lasers and their physical characteristics; (2) a discussion of each type of vascular tumor or malformation and the optimal laser treatment modality, focusing specifically on the optimal laser, when to treat, and outcomes. Our goal is for the reader to understand why a specific laser is useful for the treatment of a given lesion. By understanding the histologic characteristics of the lesion and the physical properties of the laser, we hope that the reader will understand when and how to use lasers in the treatment of vascular tumors and malformations.
Laser Basics
A Google search for lasers demonstrates that advances in laser technology and its applications to various skin conditions have expanded rapidly in the past 40 years, with an even greater acceleration in the past 15 years. With an exceptional diversity in laser options, matching the specific laser to the specific problem is critical for optimizing results and minimizing morbidity. Effective treatment starts with fully understanding laser physics, which allows appropriate application. A high priority must also be placed on laser safety, with appropriate eye protection for the patient and all personnel involved.
Laser Mechanics
The word laser is an acronym for light amplification by stimulated emission of radiation. This acronym has elements of a misnomer because light is significantly different than the energies that are traditionally considered to be radiation. Absorption of light by the tissue provides an effect, which is most often photothermal. Selective photothermolysis is the process by which controlled thermal injury is induced in a selected tissue target that absorbs light at a specific emitted wavelength. This selected target tissue is called a chromophore.
Lasers are designed to target chromophores such as hemoglobin, water, or melanin. Some laser wavelengths are absorbed by the primary chromophore and by a competing chromophore. The issue of competing chromophore absorption should be considered in the design and use of the laser. The light that is absorbed by the chromophore is converted to heat. Tissues heated to 60° to 70°C coagulate, and structural proteins, including collagen, are denatured. At more than 100°C, tissue vaporization occurs. The pulse duration of this laser energy is important in achieving the goals of treatment and minimizing undesirable effects.
To limit collateral damage, the laser wavelength usually should approximate the absorption peak of the targeted chromophore in relation to other optically absorbing molecules in the surrounding skin. This specific targeting is a key element to efficacy, but safety is further enhanced by limiting the exposure times of absorption and the resultant heating (pulse width) so that the tissue effect is further limited to the specific target. Appropriate protective cooling of adjacent structures adds another element of safety to nontargeted tissue. Thus, proper use of the laser depends on matching the wavelength, spot size, energy density, power, and duration of action (pulse width) to the specific target.
Wavelength is directly proportional to the depth of penetration within the visible wavelength spectrum (approximately 400–700 nm). Longer wavelengths effect deeper penetration, whereas shorter wavelengths exhibit greater scatter and less tissue penetration. It is also key to remember that the larger the spot size, the deeper the penetration. The pulse width is a measure of the time that the target tissues are exposed to the laser. Ideally, it should approximate the target thermal relaxation time, defined as the time it takes for a specific volume of tissue to dissipate 51% of the energy absorbed. A pulse width that is shorter than the thermal relaxation time of a blood vessel results in inadequate photocoagulation. However, a significantly longer pulse width can lead to heat dispersion to surrounding nontarget tissue. This dispersion can decrease laser effectiveness. Therefore, optimizing pulse width is critical to safety and efficacy.
Types of Lasers
The flashlamp pumped dye laser (PDL) was introduced in 1989 and revolutionized the treatment of cutaneous vascular lesions. The PDL uses a flashlamp to energize rhodamine dye and subsequently generates a pulse of yellow light. The original PDL emitted light at 577 nm and was later increased to 585 nm to allow deeper tissue penetration without losing its ability to selectively target oxyhemoglobin. Today, the most commonly used PDL systems emit wavelengths of 585 or 595 nm and are generally considered the first treatment of choice for hemangiomas and port-wine stains in the pediatric population. In addition to the excellent clinical efficacy of PDLs, the dynamic cooling devices included in certain PDL systems have also led to an outstanding safety profile by reducing the risk for epidermal injury. The more recently developed PDLs have longer wavelengths (595 and 600 nm), larger spot sizes (7–12 mm), and higher peak fluence potential, thereby allowing for better treatment of more deeply situated vessels in hemangiomas and port-wine stains.
After treatment with the PDL, most patients experience varying degrees of erythema and/or purpura, potentially lasting up to 7 to 10 days. Less common side effects of the PDL include hyperpigmentation and hypopigmentation. Atrophic scarring has been documented but is exceedingly rare.
Intense Pulsed Light Laser
Intense pulsed light laser (IPL) systems emit polychromatic light in a broad wavelength spectrum. Attached to these devices are filters designed to allow a defined wavelength band to penetrate the skin and target specific structures. Depending on the attached filter, which results in the application of wavelength bands in the range of 500 to 1400 nm, superficial or deeper vessels may be treated. Within the pediatric population, many different vascular lesions have been treated with IPL, including port-wine stains and hemangiomas.
Neodymium:Yttrium-Aluminum-Garnet Laser
The wavelength of the neodymium:yttrium-aluminum-garnet laser is 1064 nm and in the near-infrared spectral region. As is true for the CO 2 laser, the Nd:YAG requires a helium-neon aiming beam because the near-infrared spectral region is not visible to the human eye. Although most tissues in the body do not absorb this wavelength well, pigmented tissues absorb it better than do nonpigmented tissues. Laser energy is transmitted through the superficial layers of most tissues and is scattered into the deeper layers.
In comparison with the CO 2 laser, the scatter of the Nd:YAG laser is considerably greater. The depth of penetration is therefore greater, and thus the Nd:YAG laser is well suited for coagulating deeper vessels. Experimentally, the depth of maximum coagulation is about 3 mm (coagulant temperature, 60°C).
Nd:YAG lasers can penetrate deeply (4–6 mm) and have been used for years for the treatment of port-wine stains. With the deeper penetration and nonselective destruction, pain and scarring become factors during treatments. Therefore, anesthesia is usually required to help with pain control and conservative power settings, a pointillistic approach to the lesion, and avoidance of treatment in areas of thin skin are necessary to prevent posttreatment scarring. One benefit of the 1064-nm wavelength is the inherently lower absorption coefficient for melanin. With this wavelength, there is less concern for coincident pigment-induced epidermal damage and it can be used more safely in patients with higher Fitzpatrick skin types. Nevertheless, epidermal pigment must be protected in darkly pigmented individuals by using cooling and/or adjusting pulse duration. Cooling options common to 1064-nm devices include cryogen spray cooling (Dynamic Cooling Device, Candela Corporation), forced cold air, or contact cooling via chilled sapphire windows or conductive metal plates.
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