This paper describes indications for and the technique and results of trocar nephrostomy, performed by percutaneous lumbar tap of the renal pelvis with a large needle, followed by insertion of plastic tubing for temporary urinary drainage in selected cases of hydronephrosis. A previous paper1 presented our experiences with antegrade pyelography, in which pyelograms were made by lumbar puncture of large hydronephroses followed by aspiration of urine and injection of a urographic contrast medium. The present study, trocar nephrostomy, was a natural outgrowth of antegrade pyelography.
Lumbar tap of the hydronephrosis and insertion of plastic tubing is done with roentgenographic control with the patient under local anesthesia. The same precautions are observed as in performing spinal puncture. The patient lies prone. Preliminary x-ray films localize the approximate spot of puncture in relation to the landmarks of lumbar spine and vertebrae (fig. 1, inset). The skin is prepared with an