Tubeless percutaneous nephrolithotomy: Viable approach for some renal stones

May 15, 2008

Percutaneous nephrolithotomy (PNL) continues to be an effective minimally invasive approach to the treatment of large-volume renal stone disease.

Key Points

Cancun, Mexico-Percutaneous nephrolithotomy (PNL) continues to be an effective minimally invasive approach to the treatment of large-volume renal stone disease.

Much of the focus on this procedure has now shifted to decreasing postoperative morbidity, which often is related to the presence of the percutaneous nephrostomy tube with or without a ureteral stent placed post-procedure. The necessity of the percutaneous nephrostomy post-PNL has been questioned, given that it is rare that the clinician requires urgent access to the treated renal unit and that the factors surrounding such requirement are generally well accepted. As a result, the concept of tubeless PNL-ie, omitting the percutaneous nephrostomy tube placement at the end of the procedure-is emerging as a potentially viable strategy.

In the first study, presented by urology resident Douglas Berkman, MD, he and colleagues assessed the morbidity of what they call the reverse Polaris Loop tubeless PNL by reviewing the outcomes for all patients who underwent PNL since October 2006 at that institution. Fifty-three patients, 24 of whom underwent tubeless PNL, were then reviewed with respect to demographic parameters, analgesia use (narcotics and nonsteroidal anti-inflammatory drugs), pain scales, and length of stay.

Tubeless PNL patients reported lower pain scores (p=.01), used less narcotic analgesia (p=.01), and were more likely to be discharged on postoperative day 1 (p=.02) compared with the 29 patients who underwent standard PNL. No patients in the tubeless cohort required a second short-term intervention for bleeding or residual stone fragments.

"The implication of this study is that it is feasible to perform tubeless percutaneous renal surgery (resulting in decreased pain and narcotic use) without loss of renal access by using the reversed Polaris Loop method," Dr. Berkman said. "In addition, patients are able to be discharged from the hospital within 23 hours of the procedure without any catheters, tubes, stents, or stones."

Tubeless PNL for staghorn stones

In the second study, presented by Keith Xavier, MD, an endourology fellow at Columbia, the outcomes of the tubeless approach in patients with staghorn renal calculi were evaluated. The matched-pair review of the most recent 20 patients with staghorn renal calculi to undergo tubeless PNL at the institution and 20 patients who underwent standard PNL over the same time period examined stone complexity, presence of hydronephrosis, number of access tracts, OR times, change in hematocrit, hospital stay, pain scores, and analgesia use.

The tubeless PNL group was found to have a smaller decrease in hematocrit, decreased hospital stay, decreased pain scores, and decreased narcotic analgesia use. The standard PNL group was found to have shorter OR times (118 vs. 141 minutes, p<.05) and increased mean percutaneous access tracts (2.9 vs. 2.1 tracts, p<.05). Stone free-rate for the two approaches was 90%, using a definition of clinically insignificant residual fragments on computed tomography of the abdomen and pelvis performed 1 month post-procedure.