You are in: eMedicine Specialties > Plastic Surgery > SKIN Vascular, Capillary MalformationsArticle Last Updated: Oct 2, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 9
  Author: Thomas J Gampper, MD, Vice Chair, Department of Surgery, Director of Aesthetic and Laser Surgery, Associate Professor, Departments of Plastic Surgery and Clinical Neurosurgery, University of Virginia Thomas J Gampper is a member of the following medical societies: American Association of Plastic Surgeons, American Cleft Palate/Craniofacial Association, American College of Surgeons, American Society for Aesthetic Plastic Surgery, American Society for Laser Medicine and Surgery, American Society of Plastic Surgeons, Association of Academic Chairmen of Plastic Surgery, and Undersea and Hyperbaric Medical Society Coauthor(s): Ashok Tholpady, BA, MS, University of Virginia School of Medicine; Emmanuella Joseph, MD, Consulting Staff, Department of Plastic Surgery, Midwest Center for Plastic Surgery; William O Murtagh, MD, Associate Program Director, Chief, Associate Professor, Department of Surgery, Division of Plastic Surgery, St Vincent Mercy Medical Center, Medical College of Ohio Editors: Shahin Javaheri, MD, Chief, Department of Plastic Surgery, Martinez Veterans Affairs Outpatient Clinic; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Wayne Stadelmann, MD, Stadelmann Plastic Surgery, PC; Nicolas (Nick) G Slenkovich, MD, Practice Director, Colorado Plastic Surgery Center at Swedish Medical Center; Jorge I de la Torre, MD, FACS, Associate Professor of Surgery and Physical Medicine and Rehabilitation, Residency Program Director, Division of Plastic Surgery, University of Alabama at Birmingham; Director, Center for Advanced Surgical Aesthetics Author and Editor Disclosure Synonyms and related keywords: capillary malformation, capillary malformations, telangiectatic nevi, low-flow vascular malformation, birthmark, birth mark, hyperkeratotic cutaneous capillary-venous malformation, Parkes-Weber vascular lesion, capillary anomaly, low-flow vascular anomaly, Klippel-Trenaunay-Weber syndrome, Sturge-Weber syndrome, port-wine stain INTRODUCTIONSection 2 of 9
  HistoryVascular malformations have been recognized throughout history as birthmarks. The cause was thought to be maternal cravings for fruit or maternal dreams, moods, and fantasies. Although Blondel disproved these theories in 1727, some persist today. In 1866, Dugas conducted a scientific analysis of birthmarks and concluded they were caused by defects in embryologic development. Later, Dupuytren classified vascular malformations as erectile tumors. Virchow and Wagner established the first classification system of vascular malformations, based on channel architecture and histomorphologic appearance. ProblemVascular malformations have been categorized using confusing, inaccurate, and inconsistent terminology. A significant number of patients with vascular lesions receive ineffective and potentially harmful treatment based on misclassification. Mulliken classified vascular malformations using understandable and accurate nomenclature. Vascular malformations are subdivided into low-flow (capillary, venous, lymphatic, or a combination thereof) and high-flow (arterial) anomalies. Clinical, histological, histochemical, and biochemical differences and radiographic imaging findings support this classification. FrequencyThe prevalence at birth of capillary malformations is reported at 0.3% without predisposition to either sex. EtiologyCapillary malformations were once referred to as port-wine stains; this term is now outdated. Genetic studies have mapped capillary malformations to chromosome 5q14-21, showing a defect in the RASA1 gene. The RASA1 gene encodes p120 Ras GTPase-activating protein. When mutated, p120 Ras GTPase-activating protein binds to Krev-1/rap1a, an integrin β1–mediated cell adhesion and angiogenesis protein. The pathogenesis of capillary malformations is not understood. PathophysiologyCapillary malformations are the most common cutaneous vascular malformation appearing as a macular stain. Capillary malformations are represented by ectatic capillaries and medium-sized venules with thin walls and flat endothelial cells. The lack of sympathetic innervation regulating blood flow in vessels with capillary malformation is believed to produce progressive ectasia. Consequently, a characteristic red and purple lesion is seen upon examination. Unlike hemangiomas, capillary malformations do not undergo spontaneous involution. Further, the endothelium does not exhibit hyper-proliferation but has a normal turnover rate. In a study of 415 patients with capillary malformations in the fifth decade of life, Geronemus and Ashinoff found hypertrophy, nodules, or both in 65% of the capillary vasculature. In addition to these features, bridged fenestrations can be seen by scanning electron microscopy. These are normally found in venous capillaries surrounding sweat glands and hair follicles and represent areas of accelerated exchange between circulation and surrounding tissue. Controversy remains as to whether the thickening of postcapillary venules from basement membrane deposition actually occurs. ClinicalPatient history and physical examination findings are important in order to correctly classify these malformations. Appropriate treatment begins with the correct diagnosis. The general consensus is that capillary malformations are located in the dermis. They present as well-defined patches of red or purple skin discoloration at birth but may be masked by erythema of neonatal skin. Their growth correlates closely with the person’s age, becoming increasingly nodular and covering larger areas with time. Capillary malformations are commonly associated with developmental defects. For example, a capillary malformation on the posterior chest may be indicative of an underlying arteriovenous malformation (AVM) of the spinal cord (Cobb syndrome), or an occipital capillary malformation may overlie an encephalocele. Spinal dysraphism, lipomeningocele, tethered spinal cord, and diastematomyelia may be present when the capillary malformation overlies the cervical or lumbosacral spine. In these cases, careful neurologic examination, radiographic examination, spinal radiographic imaging, and bladder function studies are indicated because subtle signs of neurogenic bladder dysfunction or lower extremity weakness may be present. RELEVANT ANATOMYSection 3 of 9
Unlike hemangiomas, capillary malformations display ectatic vessels with flat nonproliferative endothelium. Thickening of the postcapillary venule wall is a common finding. In addition, bridged fenestrations can be seen by electron microscopy. WORKUPSection 4 of 9
Imaging Studies
Histologic FindingsCapillary malformations have normal ultrastructural characteristics and normal endothelial mitotic activity. Typical Weibel-Palade bodies, smooth endoplastic reticulum, and fenestrated postcapillary venules may be observed using electron microscopy. Pericytes only partially cover endothelial cells. TREATMENTSection 5 of 9
Medical TherapyReassure patients with asymptomatic lesions that the lesion is benign. Uncommonly, capillary malformations bleed after minor trauma, and the bleeding may be difficult to stop. Compression of the area and immediate medical assistance is necessary. More complex syndromes may require assessment by a team of specialists including pediatricians, radiologists, dermatologists, and plastic surgeons. Surgical TherapyThe current treatment of choice for capillary vascular malformations is the pulsed-dye laser (PDL), although only 15-20% of lesions clear completely. The wavelength and pulse duration corresponding to the optimal thermal damage is 585 nm for 450 μsec. Capillary malformations located on the medial part of the cheek, upper cutaneous lip and nose, and the V2 dermatome respond poorly to PDL. The areas that respond best to treatment include lesions in the periorbital region, the neck, and the temple. End results may be due to differences in adnexa, fibrous proteins, density of vessels, and nerves. Excision is useful for small fibrovascular nodules, but patients with extensive fibronodular hypertrophy may require resection and resurfacing with split- or full-thickness skin grafts. When mandibular prognathism or occlusal canting from hemimaxillary vertical overgrowth occurs, orthognathic procedures are indicated. Follow-upProvide monthly follow-up care to neonates with birthmarks. Hemangiomas begin proliferating within the first month, while capillary malformations enlarge commensurately with the child’s growth. Invasion of important anatomic structures, cosmetic deformity, pain, and swelling may prompt surgical treatment. Monitor patients for recurrence after lesions are resected. SYNDROMES INVOLVING CAPILLARY MALFORMATIONSSection 6 of 9
Klippel-Trenaunay-Weber syndrome Klippel-Trenaunay-Weber syndrome is often associated with the triad of capillary malformations, venous malformations or varicose veins, and hypertrophy of affected tissues. Vascular abnormalities lead to muscle hypertrophy and thickening of the skin, subcutaneous tissues, and bone. Although port-wine stains commonly occur cutaneously, venous and lymphatic malformations are common in the limbs. Most often, they affect a single lower extremity. A persistent lateral vein extending from the lateral malleolus to the gluteal region is common. Parkes Weber syndrome Parkes Weber syndrome is the combination of a capillary malformation and an AVM. It is commonly large and pink, with the affected limb being longer and warmer than the contralateral limb. Hyperkeratotic cutaneous capillary-venous malformation The hyperkeratotic cutaneous capillary-venous malformation is normally associated with vascular malformation of the brain and affects the tissue around the eye. It is an autosomal dominant abnormality due to a mutation in the KRIT1 gene. Sturge-Weber syndrome Sturge-Weber syndrome is a capillary malformation in the distribution of the ophthalmic and maxillary divisions of the trigeminal nerve of the face. This vascular malformation may be associated with many other symptoms, such as jacksonian seizures, mental retardation, calcification of the leptomeninges, glaucoma, and contralateral hemiplegia. FUTURE AND CONTROVERSIESSection 7 of 9
Classification of vascular malformations remains controversial. New findings by Breugem et al suggest that the pathologic abnormalities of capillary malformations appear to be located in postcapillary venules rather than the capillaries themselves. Thus, port-wine stains may need to be redefined from their original classification under capillary malformations. MULTIMEDIASection 8 of 9
REFERENCESSection 9 of 9
Vascular, Capillary Malformations excerpt Article Last Updated: Oct 2, 2007 | |||||||||||||||||||||||||||||||||
