Duplex Doppler Ultrasound and Portal Hypertension in Children

To the Editor: The interesting paper by Kozaiwa et al. (1), published in August 1995, again deals with the controversial issue of the usefulness of duplex Doppler ultrasound (DDU) in monitoring portal hypertension in children. We recently suggested that DDU seemed to be an unreliable tool in the management of young cystic fibrosis patients with portal hypertension at risk of esophageal varices (2). The most evident critical points were: (a) the wide overlapping of hemodynamic measurements between subjects with portal hypertension and esophageal varices and those without varices or even without liver bisease, (b) the high intraobserver variability of repeated Doppler evaluations, and (c) the difficulty of obtaining good quality measurements because of meteorism or poor cooperation. In the light of these considerations and of the debate that has been developing in the pertinent literature (3,4), we wonder if the authors' conclusion that DDU “is very useful in evaluating portal hypertension in children” is slightly optimistic. How might the clinical management of children with portal hypertension be modified by DDU? Could it save them more invasive procedures? Despite the evidence that both patients with chronic active hepatitis and those with liver cirrhosis had lower mean Vmax values than controls, there is no direct demonstration that (either as a group or in individuals) Vmax reliably reflects the pathological stage of liver disease. Considerable overlapping of data between different groups still exists, and longitudinal measurements are lacking. Moreover, DDU measurements seem to be variably related to the presence of varices and to their risk of bleeding. In consideration of the potentially devastating consequences of sudden variceal rupture and of the present therapeutic opportunities, we feel that periodic endoscopic monitoring is still worth-while. There is no doubt that in the evaluation of splanchnic circulation, DDU may theoretically offer important advantages if compared with conventional B-mode ultrasound. Nevertheless, we think that several questions regarding its reliability, actual clinical role, and practical implications for children with portal hypertension still need convincing answers. Marco Cipolli; Enrico A. Valletta; Giantonio Cazzola Cystic Fibrosis Center Pediatric Clinic Verona, Italy