Percutaneous displacement of calyceal calculi. Adjunct to percutaneous nephrolithotripsy.

Two cases are presented of successful percutaneous removal of adherent calyceal calculi which were initially inaccessible for removal with the rigid nephroscope. In each case, the calculus was dislodged from the calyceal wall by the direct force of a needle introduced percutaneously against the stone. In the first patient, a wedged calyceal calculus was dislodged percutaneously and manipulated into the renal pelvis the day before extraction using the rigid nephroscope. In the second patient, the adherent calculus was dislodged percutaneously at the same time of endoscopic removal. In both patients, prior carbon dioxide pyelography was helpful in determining the optimum direction for advancing the needle against the calculus. Percutaneous stone dislodgement technique is a useful adjunct to percutaneous nephroscopic removal of the difficult calyceal calculus.