Erect and supine radiographs to assess effectiveness of SWL for stones in a caliceal diverticulum or dilated calix

There are patients who have been treated with shockwave lithotripsy (SWL) for stones in a caliceal diverticulum (CD) or a dilated calix in whom the degree of fragmentation is difficult to assess. The aim of this study was to see if adequate fragmentation could be confirmed by the demonstration of layering of fine fragments on an erect radiograph. Over a period of 9 months, 13 patients with stones in a CD or a dilated calix with a stenosed infundibulum were studied 2 weeks after SWL with erect and supine radiographs. One of eight patients with a CD cleared all fragments. Two patients showed no change in the appearance of the stone on either the supine or the erect film, and of the remaining five patients, three demonstrated layering of sand at the base of the CD. Five patients with a dilated calix and a narrow infundibulum were also studied: two of these patients became stone free, two demonstrated complete fragmentation with layering of the sand, and in one patient, a 4-mm fragment, hidden within the sand, was revealed only on the erect film. There are patients who have been treated with SWL for stones in a CD or a dilated calix in whom adequate fragmentation is difficult to demonstrate. An erect radiograph in these patients may demonstrate layering of the fragments to confirm fragmentation and obviate repeat SWL.