[Ultrasonography in hypertrophic stenosis of the pylorus: clinico-therapeutic implications in borderline cases].
Previous publications attempted to define normal and abnormal ranges in the measurement of pyloric length (L), breadth (D), muscle thickness (S), volume (V) and muscle index (MI). We examined with US 286 patients with suspected hypertrophic pyloric stenosis and investigated all the above diagnostic criteria. Normal and abnormal ranges were in agreement in all five measurements, though less apparent for pyloric volume and muscle index. The patients with borderline values were 46 (16%) for pyloric muscle thickness, 98 (34%) for breadth, 52 (18%) for length, but only 22 (7.7%) for pyloric volume and muscle index. Borderline patients received medical therapy with the antispasmodic drug metaclopramide hydrochloride and they were examined with US after 15 days. Only 8 of 22 borderline patients (36%) developed a typical hypertrophic pyloric stenosis. In the others, pyloric volume was reduced and the symptoms subsided. Pyloric parameters cannot be always measured accurately, but pyloric volume and muscle index measures better distinguish normal from abnormal findings. The formula for pyloric volume calculation is simpler than that for pyloric muscle index calculation and easier to memorize, also because no correction for body weight is necessary.