PURPOSE:The determine the usefulness of urinalysis in monitoring patients with distal ureterolithiasis.MATERIALS AND METHODS:Patients with microhematuria who were found to have a distal ureteral stone and who were candidates for conservative management were enrolled in the study. Patients were typically seen in clinic at 1 to 2 weeks after initial diagnosis and reassessed. A urinalysis, including office dipstick and automated laboratory analysis using the IQ 200 IRIS analyzer, were performed. The absence or presence of microhematuria was determined and compared with results of repeated unenhanced helical CT of the abdomen and pelvis to determine the sensitivity, specificity, and positive and negative predictive values of urinalysis.RESULTS:Twenty-nine patients were enrolled in this prospective study. The mean age of the patients was 43.5 years. The sex distribution was predominantly male, with 72% men and 28% women. Ultimately, 18 patients are included in our analysis with the remainder either lost to follow-up or excluded because of protocol violation. Average distal stone size was 4.1 mm (range 2.0-6.5 mm). Stones were evenly distributed between the right and the left ureters, with 50% on either side. Mean time to follow-up was 18 days with a range of 2 to 63 days. The sensitivity of urinalysis was determined to be 40% (8%-72%) while the specificity was 63% (28%-98%). The predictive value of a positive test was 57% (19%-95%) and the predictive value of a negative test was 55 % (25%-85%). The confidence interval for each of these parameters is inclusive of the value of 50%, indicating that urinalysis is no better than randomness in predicting presence or absence of a stone by CT.CONCLUSIONS:The absence or presence of microhematuria does not accurately predict whether a distal ureteral stone has passed or is still present. In those patients who need or want to know whether a stone is still present, unless a stone is strained, we suggest repeated CT imaging.

Introduction: Interleukin-6 (IL-6), an inflammatory marker, has previously been found to be elevated in the urine of patients with urolithiasis. Oxalate and other stone precursors have been shown to increase IL-6 production in proximal tubular epithelial cells in vitro. We examined whether urinary IL-6 could be used as a screening test to determine current urolithiasis in individuals who are known to form urinary stones.Methods: Thirty-five adult patients with current urolithiasis demonstrated on imaging were enrolled in the study. Exclusion criteria included disease known to elevate IL-6. Each patient provided a pre-treatment urine specimen and one month after proven to be stone-free an additional urine specimen was obtained. The urinary IL-6/creatinine ratio was determined for both specimens and compared.Results: Ten patients provided both specimens. The mean pre-operative urinary IL-6/creatinine ratio before the procedure was 1.63 pg/mL. The mean post procedure urinary IL-6/creatinine ratio after the patient was confirmed to be stone-free was 1.81 pg/mL. These were not significantly different (p = 0.38). Preoperative urinary IL-6/creatinine ratio did not correlate to stone size (r = 0.15) and no correlation was seen between time from treatment and stone free IL-6/creatinine ratio (r = 0.48).Conclusion: Urinary IL-6 is not a good screening test for current urolithiasis in stone-forming individuals. It is elevated whether the stone is present or not.

PURPOSEWe routinely perform percutaneous nephrolithotomy (PCNL) without the use of nephrostomy tubes. We examined the need for secondary surgery for the treatment of residual stones in patients who underwent both tubeless surgery and PCNL with tube placement.PATIENTS AND METHODSWe retrospectively reviewed the charts of 180 patients who underwent 186 percutaneous nephrolithotomies. Among them, 125 patients had tubeless surgery, and 61 had nephrostomy tubes. We compared the need for ancillary surgical procedures for residual stone disease in the two groups.RESULTSA total of 99 patients (79%) without tubes and 25 (41%) of those with tubes were stone free after surgery. A total of 45 ancillary procedures were performed for residual stone disease, with 15% of the tubeless and 43% of the patients with tubes requiring a second procedure. Extracorporeal shockwave lithotripsy (SWL) was the most common ancillary procedure.CONCLUSIONSPatients who are eligible for tubeless PCNL are unlikely to need a secondary procedure, and residual stones can most often be treated with SWL. Patients who required nephrostomy tubes had more complicated disease and a greater need for subsequent surgery.