Coarctation of the aorta

Ding et al. report in the current number of the AMS [1] a 12 year old patient with abdominal coarctation of the aorta above the renal arteries treated successfully with percutanous transluminal angioplasty. This report is a useful reminder that hypertension maybe the sole manifestation of aortic coarctation that has an estimated incidence of 1 in 2500 live births [2] and may vary from a single constriction to a tubular hypoplasia of the aorta. The localization of the aortic constriction in this patient was in the abdominal aorta, above the renal arteries, and this variety or coarctation is rare (0.2-2.0%). Constriction of the aorta in this area is frequently associated, but not in this patient, with stenosis of renal, celiac or mesenteric arteries, causing the “middle-aortic dysplastic syndrome” or “middle-aortic syndrome” (MAS) that is a feature of several congenital and acquired clinical conditions [3]. The possibility of genetic factors is suggested by the report of the disease in monocygotic twins [4] and autosomal dominant inheritance in familial cases [5]. Gridlock mutations in the hey2 gen induce in the zebrafish changes similar to aortic coarctation that may be corrected with induced upregulation of vascular endothelial growth factor [6], but the relevance of these studies to human disease remain to be demonstrated. Other possible causes include the local accumulation of constricting fibrous tissue similar to that in arterial duct resulting from increased collagen gene expression induced locally by hemodynamic abnormalities in the distribution of the blood flow in the aorta [7-9]. Hypertension with absent pulses in the lower extremities was the clinical presentation of the patient described by Ding et al. [1] and the diagnosis was confirmed by computed tomography (CT) angiography. It is not unusual that patients are not diagnosed until adolescence or adulthood but it should be emphasized that an early diagnosis is important because the development of left ventricular hypertrophy and heart failure worsen the prognosis. Prenatal diagnosis of aortic coarctation is difficult and relays in serial fetal echocardiographic determinations of isthmal-ductal ratios [10] but neonatal diagnosis is possible and balloon dilatation has been used successfully in neonates weighing less than 2500 g with significant reduction of transcoarctation gradient [11]. However, restenosis is common and may develop rapidly. Repair of coarctation can be made by surgical correction (end to end anatomosis or subclavian flap repair to increase the size of the aorta) or by balloon angioplasty, with or without stent placement. In the patient reported by Ding et al. [1] the location and limited size of the constriction made it particularly amenable to angioplasty. Coarctation repair by balloon angioplasty has gained widespread acceptance Corresponding author: Bernardo Rodriguez-Iturbe Servicio de Nefrología Hospital Universitario de Maracaibo Universidad del Zulia and Centro de Investigaciones Biomédicas Instituto Venezolano de Investigaciones Científicas (IVIC)-Zulia Venezuela E-mail: [email protected] Editorial