Submucosal migration of ureteric calculi: related to ESWL?

Three patients were reinspected by ureteroscopy after repeat ESWL. Ureteroscopy initially did not disclose an intraluminal stone and only visualized a severe inflammatory reaction of the ureteric wall and a boss of the ureter at the level of the fluoroscopically suspected stone location. An intact stone in all 3 cases was finally exposed by tactile contact at the top of the ureteroscope after perforating the mucosa with a guide wire. Retrospectively, the combination of long-standing stone impaction together with damage to the ureteric mucosa during shockwave interaction may cause an inflammatory reaction with submucosal migration of the stone.