A Randomized Controlled Comparison of Nephrostomy Drainage vs Ureteral Stent Following Percutaneous Nephrolithotomy Using the Wisconsin StoneQOL - Commentary

Percutaneous nephrolithomy (PCNL) is the gold standard for removing large renal stones, having been shown to be safe, decrease length of stay (LOS) and perioperative pain. Trend in recent years favor has been in favor of a “tubeless” PCNL. Quality-of-life (QoL) is an important factor in decision-making for treatment and patient’s consideration however, no studies have evaluated the QOL of drainage tubes on patients. The Wisconsin StoneQOL is a validated disease specific instrument that assesses health-related QoL of patients with nephrolithiasis by capturing the symptoms and challenges associated with stone formers1. The aim of this study is then to compare postoperative outcomes and QoL between nephrostomy tube drainage vs ureteral stent placement after PCNL using the Wisconsin StoneQOL.

Between September 2015 and March 2016, 30 patients with nonobstructing renal calculi undergoing PCNL enrolled in the randomized, prospective, double-blind study. Patients were randomized into two groups, cope loop nephrostomy drain or a Double-J ureteral stent, with patient characteristics comparable between both groups. Inclusion criteria for the study include normal preoperative renal function, uncomplicated procedure without significant intraoperative blood loss, no history of PCNL, and apparent stone-free status at tend of postoperative imaging. During the procedure, nephrostomy tubes were removed within 48 hours before discharge, and ureteral stents were removed at least 2 weeks after surgery. Patients’ QOL was assessed preoperatively with the Wisconsin StoneQOL, 7 to 10 days post surgery, and then 30 days using same questionnaire. The primary outcome was the preoperative and postoperative QoL scores, and secondary outcomes included perioperative characteristics, inpatient analgestic requirements, LOS, and postsurgical complications.

The results of the study showed significant difference between preoperative and postoperative health-related QoL at 7-10 days. Patients in Group 2 not only had significantly worse QoL changes, but also higher negative responses on the StoneQOL assessment, including those not associated with the stent such as nocturia, frequency, and urgency. There were no significant differences between any of the secondary outcomes, which included stone-free rate, operative times, estimated blood loss, LOS, and complications. Inpatient analgesic requirements were also comparable. At postoperative 30 days, both groups had similar or improve QoL status relative to their baseline. Some limitations of the study included small sample size and recognition that QoL changes postoperatively were not measured on a daily basis.

In conclusion, tubeless PCNL with urethral stent placement did not significantly reduce hospital LOS or inpatient analgesic requirements when compared to nephrostomy tube drainage for 48 hours after surgery. In addition, patients reported worse outcomes and lower scores on Wisconsin StoneQOL 7-days days post surgery for urethral stent. This reveals improvement of immediate postoperative pain through reduction of nephrostomy tube size. Additional trials and studies on QoL following PCNL is needed for better optimize patient care and treatment.

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Authors: Philip T. Zhao, MD, David M. Hoenig, MD, Arthur D. Smith, MD, and Zeph Okeke, MD

Affiliations: Smith Institute of Urology, Northwell Health System, New Hyde Park, NY

Reference:

1. Penniston KL, Nakada SY. Development of an instrument to assess the health related quality of life of kidney stone formers. J Urol 2013;189:921–930.