Papillary vs Nonpapillary Puncture in Percutaneous Nephrolithotomy: A Prospective Randomized Trial

Percutaneous nephrolithotomy has undergone considerable evolution since its introduction in the 1970s, which has been driven by advances in access techniques, instrumentation and endoscopic technology. Recent reports suggest an increase in the number of percutaneous stone treatments being performed. However, despite the increasing use of percutaneous nephrolithotomy a minority of urologists obtain their own access. We reviewed the techniques for performing safe and effective percutaneous renal access. A literature search using Entrez PubMed was performed. All relevant literature concerning techniques for fluoroscopic percutaneous renal access published within the last 20 years was reviewed. The success of percutaneous nephrolithotomy is critically dependent on achieving suitable percutaneous access. The ideal site of percutaneous puncture should be selected to maximize the use of rigid instruments, minimize the risk of complications and attain stone-free status. Familiarity with basic renal anatomy is essential to obtain access safely. Adherence to basic principles allows the establishment of percutaneous access in a straightforward and efficient manner. Certain clinical situations may require special access techniques. Percutaneous nephrolithotomy is the treatment of choice for complex stone disease. While the efficacy of percutaneous nephrolithotomy relies on the establishment of effective percutaneous access, there are considerable advantages for the urologist able to achieve access.

There are several positions in the operation of percutaneous nephrolithotomy (PCNL), such as prone position, supine position, flank position, and modified supine position for PCNL, but the supine and prone positions are the main two choices for several years. However, there is still discrepancy on the optimal position for PCNL. Therefore, we performed this meta-analysis to evaluate safety and efficacy of the supine versus the prone position in PCNL for renal calculi.

In an attempt to determine the best route to puncture and access the kidney collecting system we studied 62, 3-dimensional polyester resin endocasts of the pelvicaliceal system together with the intrarenal vessels. A retrograde pyelogram was obtained, and the arterial and venous trees were injected with red and blue resins, respectively. When the resin was still in the gel state, the kidneys were positioned at 30 to 45 degrees and the collecting system was punctured under radioscopy. Since the resin is not opaque to x-ray the operator was not able to visualize the vessels while puncturing. After puncture, the needle was maintained in place, the contrast medium was removed and the pelvicaliceal system was filled with yellow resin. After the resin had set, the renal organic matter was corroded in acid and the endocast was obtained (with the needle in the original position). This type of preparation allowed us to examine the needle tract and the vessels damaged during the puncture. In the same kidney we punctured the superior pole, mid kidney and inferior pole. In some cases we also punctured the renal pelvis. We performed 104 punctures through an infundibulum, 39 through a fornix of a calix and 12 through the renal pelvis. Due to a high percentage of vascular lesions, intrarenal access through an infundibulum should be avoided. Also, renal pelvis puncture should be avoided. Regardless of the kidney region, puncture through a fornix of a calix was safe.