One-step percutaneous nephrolithotomy sheath versus standard two-step technique

Advances in technique and equipment have allowed urologists to perform percutaneous stone removal with increasing efficacy and decreasing complications. The procedure of choice for large renal calculi is percutaneous nephrolithotomy. At our institution, percutaneous access is achieved by a two-step process using either Amplatz dilators or placement of a high-pressure balloon catheter for tract dilation, followed by advancement of a sheath over the balloon. A novel device, the Pathway Access Sheath (PAS) has been developed that allows for balloon tract dilation and percutaneous access sheath placement in one simple step.

Our study population consisted of 21 patients, who were randomized to one of two arms. Of the 21 patients, 10 underwent standard two-step access using a high-pressure balloon catheter and 11 underwent percutaneous nephrolithotomy using the novel PAS. We compared the insertion time, blood loss, and cost between the two techniques.

The average insertion time was shorter in the PAS group (3 minutes) compared with the high-pressure balloon catheter (5 minutes, 42 seconds); a difference that was statistically significant (P <0.01). The estimated blood loss and cost were similar between the two groups. The increased sheath flexibility of the PAS was noted to be an advantage in some patients.

The results of our study have shown that a novel single-step renal access device is safe and efficacious and results in a shorter insertion time for percutaneous nephrolithotomy. Blood loss was less in the PAS group as well, although the difference was not statistically significant. Additional studies will establish whether this device will provide a new standard of obtaining renal access.