Sclerotherapy of Rectal Venous Malformations in a Child With Klippel‐Trenaunay Syndrome

To the Editor: Parashette and Cuffari (1) described ethanol sclerotherapy of venous malformations of the rectum in a child with Klippel-Trenaunay syndrome (KTS). We wish to comment on their diagnosis and conclusions. Misdiagnosis and mismanagement are common in vascular anomalies because of poor adherence to correct terminology (2). In 1982, Mulliken and Glowacki classified vascular anomalies into 2 broad categories (3). This system has been adopted by the International Society for the Study of Vascular Anomalies and is used by most specialists who treat these conditions. Vascular anomalies are divided into vascular malformations, which present typically at birth and grow commensurately with the child, and vascular tumors, which include infantile hemangiomas. Infantile hemangiomas typically involute within the first few years of life (2), usually do not require any treatment, and rarely occur in the bowel. Although the International Society for the Study of Vascular Anomalies classification explicitly avoids eponyms, KTS, as described by Klippel and Trenaunay in 1900 (4), is a coherent entity, and the term is still used to describe patients with venous, capillary, and sometimes lymphatic anomalies of a limb, often associated with overgrowth of soft tissues and bone, and sometimes with coagulopathy (5,6). “Klippel-Trenaunay-Weber syndrome,” however, is an erroneous conflation of 2 distinct conditions (7). The term Parkes Weber syndrome (PWS) is used to describe a disease quite different from KTS, in which diffuse microscopic arteriovenous malformations of a limb are accompanied by overgrowth (8). PWS with multifocal capillary malformations and arteriovenous malformations is caused by mutations in RASA1, a guanosine triphosphatase activating protein (9). Mutations in another gene, AGGF1, have been proposed as a predisposing (but not sufficient) factor for KTS (10). There are, therefore, important differences in the pathogenesis, clinical features, prognosis, and treatment of KTS and PWS (7,8). The vascular lesions described in Parashette and Cuffari's patient are venous malformations (VMs). VMs commonly occur in the pelvis as part of KTS. They do not involute and are a lifelong problem. Sclerotherapy is a reasonably effective treatment for VMs, syndromic or nonsyndromic, at almost all anatomic sites (2). Parashette and Cuffari state that sclerotherapy “was shown to be safe and effective,” and imply that postoperative complications and recurrent symptoms are less likely than with surgery. It is unwise to draw this conclusion on the basis of a single case. In fact, complications of ethanol sclerotherapy are not rare and can include pulmonary hypertension, pulmonary embolism, and even death (11). Parashette and Cuffari are to be congratulated for using fluoroscopic guidance for rectal sclerotherapy because this allows the demonstration of possible communications between the VMs and abnormal pelvic veins (12) or the inferior mesenteric vein (13), either of which may be a risk factor for catastrophic complications. No one knows whether recurrent symptoms are more common after sclerotherapy or surgery. A better conclusion to this case report would have been that surgery and sclerotherapy have different types of complications, that there is no known “best” treatment, and that management should be based on multidisciplinary assessment in each individual patient.