Percutaneous nephrostomy--technique.

Percutaneous nephrostomy is increasingly used for temporary relief of upper urinary tract obstruction. The technique described involves the use of angiographic catheters and guides, and will provide drainage for several weeks or months. The patient is placed in the prone oblique position after intravenous contrast to opacify the kidneys. The oblique position ensures that a needle advanced vertically toward the kidney will pass along a posterior oblique line, entering the outer aspect of the kidney away from the hilum and directing guide wires and catheters toward the ureter. A fine needle is passed vertically into the kidney to determine its depth and to provide a pyelogram. A needle-cannula is then directed at the collecting system along a similar line until urine comes back. An angiographic J-guide is introduced and the needle exchanged for a series of vessel dilators, to dilate the track through the tissues. Finally, a catheter is passed over the guide wire into the collecting system, secured to the patient and attached to the drainage bag. Other maneuvers such as ureteral stenting can be added to this technique. The complications and technical difficulties are discussed.