Vascular Anomalies Classification: Recommendations From the International Society for the Study of Vascular Anomalies.

Vascular anomalies represent a spectrum of disorders from a simple "birthmark" to life- threatening entities. Incorrect nomenclature and misdiagnoses are commonly experienced by patients with these anomalies. Accurate diagnosis is crucial for appropriate evaluation and management, often requiring multidisciplinary specialists. Classification schemes provide a consistent terminology and serve as a guide for pathologists, clinicians, and researchers. One of the goals of the International Society for the Study of Vascular Anomalies (ISSVA) is to achieve a uniform classification. The last classification (1997) stratified vascular lesions into vascular malformations and proliferative vascular lesions (tumors). However, additional disease entities have since been identified that are complex and less easily classified by generic headings, such as capillary malformation, venous malformation, lymphatic malformation, etc. We hereby present the updated official ISSVA classification of vascular anomalies. The general biological scheme of the classification is retained. The section on tumors has been expanded and lists the main recognized vascular tumors, classified as benign, locally aggressive or borderline, and malignant. A list of well-defined diseases is included under each generic heading in the "Simple Vascular Malformations" section. A short definition is added for eponyms. Two new sections were created: one dealing with the malformations of individually named vessels (previously referred to as "truncular" malformations); the second groups lesions of uncertain or debated nature (tumor versus malformation). The known genetic defects underlying vascular anomalies are included in an appendix. This classification is meant to be a framework, acknowledging that it will require modification as new scientific information becomes available.

RASA1 mutations and associated phenotypes in 68 families with capillary malformation-arteriovenous malformation.

Capillary malformation-arteriovenous malformation (CM-AVM) is an autosomal-dominant disorder, caused by heterozygous RASA1 mutations, and manifesting multifocal CMs and high risk for fast-flow lesions. A limited number of patients have been reported, raising the question of the phenotypic borders. We identified new patients with a clinical diagnosis of CM-AVM, and patients with overlapping phenotypes. RASA1 was screened in 261 index patients with: CM-AVM (n = 100), common CM(s) (port-wine stain; n = 100), Sturge-Weber syndrome (n = 37), or isolated AVM(s) (n = 24). Fifty-eight distinct RASA1 mutations (43 novel) were identified in 68 index patients with CM-AVM and none in patients with other phenotypes. A novel clinical feature was identified: cutaneous zones of numerous small white pale halos with a central red spot. An additional question addressed in this study was the "second-hit" hypothesis as a pathophysiological mechanism for CM-AVM. One tissue from a patient with a germline RASA1 mutation was available. The analysis of the tissue showed loss of the wild-type RASA1 allele. In conclusion, mutations in RASA1 underscore the specific CM-AVM phenotype and the clinical diagnosis is based on identifying the characteristic CMs. The high incidence of fast-flow lesions warrants careful clinical and radiologic examination, and regular follow-up.

The practice of pediatric interventional radiology.

There is a stark contrast between adult and pediatric interventional radiology practice. The essential elements of this all relate to working with children, including a need for greater procedural sedation and anesthesia; the psychology of working with children and their families; a skill set based around smaller bodies; and technology for smaller and growing humans. Interventional radiology departments that cater to children need to accommodate these factors so that sick children can access minimally invasive image-guided therapy in a safe and nonthreatening environment.

Embolization in neonates and infants.

Several conditions presenting in the neonatal and infant period benefit from embolization, including hemangioma, vascular shunts, and tumors. The physiological delicacy and small size of newborns create distinct challenges. This paper discusses embolization of these patients and illustrates the techniques involved.

Intensive care experience with sclerotherapy for cervicofacial lymphatic malformations.

OBJECTIVE: To describe a cohort of patients needing intensive care support after sclerotherapy for cervicofacial lymphatic malformations. DESIGN: Retrospective review of case records of patients undergoing sclerotherapy between January 2004 and November 2006. SETTING: A tertiary, university-affiliated, pediatric teaching hospital. PATIENTS: Five patients needing admission to a pediatric intensive care unit (PICU) following sclerotherapy with OK432. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Five patients needed a total of 13 PICU admissions. Ages ranged from 4 months to 19 months. All patients had extensive lesions that involved the airways, mediastinum, or floor of the mouth, documented by magnetic resonance imaging. Nine admissions involved elective intubation and ventilation following sclerotherapy due to the extent of lesions. There were four urgent admissions to the PICU with respiratory distress ranging from 3 to 18 days after sclerotherapy. The mean duration of admission was 7 days (total 93 days, range 2-22 days). Total ventilated hours were 1656 hrs with a range of 16.5-370 hrs per admission. Multiple procedures, such as drainage of cysts and further sclerotherapy procedures, were performed before extubation on the PICU. CONCLUSIONS: Children with extensive disease and airway involvement need multiple PICU admissions. The potential for life-threatening respiratory embarrassment is unpredictable following sclerotherapy. Consideration should be given to performing further sclerotherapy while the patients are intubated in the PICU. The PICU provides a safe and secure environment for such procedures.

Post-liver transplant mycotic aneurysm of the hepatic artery.

BACKGROUND: Mycotic aneurysm of the hepatic artery is a rare complication of liver transplantation, occurring in 0% to 3% of patients and having a mortality of around 30%. We present a unique report of mycotic aneurysms of the hepatic artery following liver transplantation in children. METHODS AND RESULTS: A chart review of the 194 patients who underwent a liver transplantation over a 21-year period revealed 2 patients who developed a mycotic aneurysm of the hepatic artery. The first patient died due to rupture prior to diagnosis. The second patient was treated successfully using radiological coil embolization, followed by surgical excision with hepatic artery ligation and antibiotic therapy. CONCLUSIONS: Early diagnosis and prompt multidisciplinary treatment is crucial to optimize treatment in this condition.

Late-onset inferior vena cava obstruction in a shunted patient--a unique cause of rebleeding in children with portal hypertension.

BACKGROUND: Rebleeding in the presence of an adequate patent portosystemic shunt in a patient with portal hypertension (PHT) is uncommon. Inferior vena cava (IVC) obstruction as the cause of rebleeding in this situation has not been reported in the literature. METHODS: Records from a pediatric tertiary care center were reviewed over a 15-year period. Portosystemic shunt procedures for bleeding esophageal varices were done in 39 children. Patients who, after a shunt surgery for PHT, developed a rebleed because of IVC obstruction in the presence of a patent shunt were identified. RESULTS AND CONCLUSIONS: Late IVC obstruction in the presence of a patent shunt was identified in 2 patients. The etiology included adhesions, caudate lobe hypertrophy, and macronodular cirrhosis. Diagnosis was by angiography, and treatment included angioplasty and liver transplantation. Awareness of this condition helps direct treatment appropriately in the clinical scenario of a rebleed in a shunted patient with PHT.