Objective To assess the effectiveness of L-cystine dimethyl ester (CDME), an inhibitor of cystine crystal growth, for the treatment of cystine urolithiasis in a Slc3a1 knockout mouse model of cystinuria. Methods CDME (200 μg per mouse) or water was delivered by gavage daily for four weeks. Higher doses by gavage or in the water supply were administered to assess organ toxicity. Urinary amino acids and cystine stones were analyzed to assess drug efficacy using several analytical methods. Results Treatment with CDME led to a significant decrease in stone size compared with the water group (p = 0.0002), but the number of stones was greater (p = 0.005). The change in stone size distribution between the two groups was evident by micro computed tomography. Overall, cystine excretion in urine was the same between the two groups (p = 0.23), indicating that CDME did not interfere with cystine metabolism. SEM analysis of cystine stones from the CDME group demonstrated a change in crystal habit, with numerous small crystals. L-cysteine methyl ester was detected by UPLC-MS in stones from the CDME group only, indicating that a CDME metabolite was incorporated into the crystal structure. No pathological changes were observed at the doses tested. Conclusions These data demonstrate that CDME promotes formation of small stones but does not prevent stone formation, consistent with the hypothesis that CDME inhibits cystine crystal growth. Combined with the lack of observed adverse effects, our findings support the use of CDME as a viable treatment for cystine urolithiasis.

Cystinuria is an incompletely dominant disorder characterized by defective urinary cystine reabsorption that results in the formation of cystine-based urinary stones. Current treatment options are limited in their effectiveness at preventing stone recurrence and often poorly tolerated. We report that the nutritional supplement α-lipoic acid inhibits cystine stone formation in the Slc3a1-/- mouse model of cystinuria by increasing the solubility of urinary cystine. These findings identify a novel therapeutic strategy for the clinical treatment of cystinuria.

Objective To report our experience with ureteroenteric anastomotic revision as initial treatment of stricture after urinary diversion. Methods An institutional review board‐approved retrospective study was carried out. A total of 41 patients who underwent primary ureteroenteric anastamotic revision were identified between 2007 and 2015. Data analyzed included patient characteristics, type of diversion, estimated blood loss, operative time, change in renal function, length of stay, postoperative complications and time with nephrostomy/stent. Success of revision was defined as an improvement in hydronephrosis on radiographic imaging and/or reflux during pouchogram. Predictors of length of stay and complications were analyzed using analysis of covariance. Results A total of 50 renal units were revised with a success rate of 100%. The median length of stay was 6 days (2–16 days). There were a total of 15 complications (one major, 14 minor) in 14 patients (33% 30‐day complication rate). The most common were wound infection (n = 4) and arrhythmia (n = 4). Robotic revision (n = 5) had a median length of stay of 3 days (2–4) with no complications. Conclusions Primary ureteroenteric anastomotic revisions have an excellent success rate at an experienced center and might obviate the need for multiple interventions. Open revision is associated with mostly minor complications. Robotic revision might reduce the morbidity of open revision in select cases.