Prospective Randomized Evaluation of Idiopathic Hyperoxaluria Treatments.

Purpose: Calcium oxalate (CaOx) stone formation is influenced by urinary oxalate excretion. Stone formers with elevated urinary oxalate are commonly prescribed a low-oxalate diet or oral supplementation with vitamin B6 and magnesium to reduce urinary oxalate excretion. This study aims to compare the effects of dietary modification vs supplementation vs a combination of both on urinary oxalate. Materials and Methods: We enrolled patients with a documented history of CaOx stones and newly diagnosed idiopathic hyperoxaluria. Patients were randomized into three treatment groups: low oxalate diet (D), supplementation with 25 mg vitamin B6 and 400 mg magnesium oxide (S), or both low oxalate diet and B6/magnesium supplementation (DS). Baseline and 3-month postintervention 24-hour urine tests were obtained. The primary endpoint was change in 24-hour urinary oxalate (Ox24) at 12 weeks. Secondary endpoints included changes in other 24-hour urine parameters, compliance rates, and adverse effect rates. Results: In total, 164 patients were recruited and 62, 47, and 55 were enrolled into the D, S, and DS groups, respectively. Of these, 99 patients completed the study (56.5% of the D, 72.3% of the S, and 54.6% of the DS groups, respectively). Significant differences were noted in median percent reduction in Ox24 values (-31.1% vs -16.0% vs -23.9%, p = 0.007) in the D, S, and DS groups, respectively. Furthermore, the percentages of patients within each treatment arm who realized a decrease in Ox24 were also found to be significantly different: D = 91.4% vs. S = 67.6% vs DS = 86.7%, p = 0.027. No significant adverse events were observed in any of the study arms. Conclusion: Low oxalate diet is more effective than B6/magnesium supplementation at lowering urinary oxalate in idiopathic hyperoxaluric stone formers. Combination therapy did not produce greater reductions in urinary oxalate than either of the monotherapy arms suggesting it is of little clinical utility. Further study with long-term longitudinal follow-up is required to determine if these treatment strategies reduce recurrent stone events in this population.

A Randomized, Double-Blind, Sham-Controlled Study Assessing Electroacupuncture for the Management of Postoperative Pain after Percutaneous Nephrolithotomy.

INTRODUCTION: Percutaneous nephrolithotomy (PCNL) is the gold standard procedure for large renal calculi but postoperative (PO) pain remains a concern. Modifications of the PCNL technique and intraoperative and PO strategies have been tested to reduce pain. PO pain control reducing risk of long-term pain medication and narcotic use is of considerable importance. Acupuncture is a common medical procedure shown to alleviate PO pain. Some benefits are that it is nonpharmacologic, easy to administer, and safe. The purpose of this study was to evaluate the effects of electroacupuncture (EA) on PO pain in patients undergoing PCNL. MATERIALS AND METHODS: This was a randomized, double-blind, sham-controlled study. The study was Institutional Review Board approved and performed under standard ethical guidelines. Fifty-one patients undergoing PCNL by a single surgeon were randomized to one of the three groups: true EA (n = 17), sham EA (SEA, n = 17), and no acupuncture (control, n = 17). The EA and SEA were performed by a single licensed acupuncturist <1 hour before operation. PCNL was performed without the use of intraoperative nerve block(s) or local anesthetic. Pain scores (visual analog scale [VAS]), narcotic use (morphine equivalents), and side effects were recorded at set intervals postoperatively. RESULTS: Mean VAS scores for flank and abdomen pain were lower at all time periods in the EA compared with the SEA and control groups. Mean cumulative opioid usage was lower in the EA group immediately postoperatively compared with both SEA and control groups. Two patients in the EA group did not require any PO narcotics. No differences between groups were found for PO nausea and vomiting. No adverse effects of EA or SEA were noted. CONCLUSIONS: EA significantly reduced PO pain and narcotic usage without any adverse effects after PCNL. This promising treatment for managing PO pain warrants further investigation.

Tips and tricks for the management of retained ureteral stents.

BACKGROUND AND PURPOSE: Retained ureteral stents, especially those that are encrusted and associated with a stone burden, can be a difficult management problem. We review our experience and the different options employed for treating this complication. PATIENTS AND METHODS: From July 1998 to February 2002, 26 retained ureteral stents were managed in our department. The average patient age was 45.9 years (range 8-77 years). The average time the stent had been in place was 10.7 months (range 3-28 months). Prior to planning definitive therapy, a plain radiograph with tomographic views was reviewed. RESULTS: A guidewire or Glidewire was often placed adjacent to the stent in order to maintain ureteral access and in some cases was able to facilitate removal of the retained stent. The patients required an average of 2.7 endourologic procedures (range 1-4) performed at one or more sessions to remove the stent and all associated stone burden. If the stone burden could not be entirely removed then stent extraction and subsequent sessions were performed until stone-free status was achieved. Cystolitholapaxy was required to treat the distal component of stent encrustation in 20 cases. Percutaneous nephrolithotomy was performed in four patients, antegrade ureteroscopy with or without intracorporeal lithotripsy in four patients, retrograde ureteroscopy with or without laser lithotripsy in five patients, and extracorporeal shockwave lithotripsy in seven patients to treat the proximal component of stent encrustation. The stent could be removed in a single anesthetic session in 23 of 26 cases (88.5%). Analysis revealed that the major component of the encrustations was a combination of calcium oxalate and phosphate. CONCLUSION: Successful management of retained ureteral stents requires careful planning and may entail a combination of endourologic approaches. It is imperative to avoid using significant force, which can result in severe ureteral injury or breakage of the stent. If encrustations are present along the stent, we believe in treating the distal component prior to managing any proximal or ureteral components.