Management of distal ureter and bladder cuff at the time of nephroureterectomy: surgical techniques and predictors of outcome.

Open radical nephroureterectomy (NU) with removal of the ureter and bladder cuff is the 'gold standard' in the treatment of high-grade urothelial cancers of the upper urinary tract. A salient issue is the management of the distal ureter and bladder cuff at time of surgery. Which technique confers superior oncologic benefit is of particular interest since this disease process is notoriously plagued with high intravesical recurrence rates. Although open radical NU is the 'gold standard', the maturation of minimally invasive surgery formidably challenges approaches considered 'gold standard'. We thus sought to critically review the literature comparing perioperative and oncologic outcomes in the approaches used to manage the distal ureter and bladder cuff in patients undergoing radical NU.

Comparison of complication rates for unilateral and bilateral percutaneous nephrolithotomy (PCNL) using a modified Clavien grading system.

OBJECTIVE: To compare complication rates of unilateral vs bilateral percutaneous nephrolithotomy (PCNL) using the modified Clavien grading system. PATIENTS AND METHODS: Single-institution retrospective chart review. Identified patients who had synchronous bilateral PCNL (B-PCNL) over an 11-year period (2000-2011). B-PCNL patients were matched by age, gender, and stone burden per renal unit with patients who underwent unilateral PCNL (U-PCNL) over the same period. Complications were recorded and classified using the modified Clavien classification system, and then compared with a two-sided chi-square test of proportions. RESULTS: In all, 47 B-PCNL patients [mean (range) age 54 (14-84) years] and 78 U-PCNL patients [mean (range) age 54 (17-91 years] were compared. The mean (range) stone burden per renal unit was 2.8 (0.7-7.0) cm and 2.9 (0.7-9.0) cm, respectively. The overall complication rate was higher for B-PCNL (53.2% vs 30.8%, P = 0.013). Rates of Grade I and Grade II complications trended toward being higher in the B-PCNL group. Low-grade complications (Grade I and II combined) occurred more often in the B-PCNL group (P = 0.011); the most common low-grade complication was fever. Two procedures terminated for poor visualisation due to bleeding were successfully completed in delayed fashion with no transfusion and were classified as Grade I complications. There were equivalently low rates of Grade III complications. There were no Grade IV or V complications. CONCLUSIONS: B-PCNL carries a higher overall complication rate than U-PCNL when the modified Clavien system is used for classification. Patients undergoing U-PCNL who have more than one tract dilatation have a higher complication rate than those who have only one tract dilatation. High-grade complications are uncommon for both procedures.

Metabolic syndrome and urinary stone composition: what factors matter most?

OBJECTIVE: To determine which metabolic syndrome (MetS) factors lead to differences in stone composition in a multivariate analysis. METHODS: We retrospectively reviewed medical charts of patients who had a kidney stone removed over a 5-year period (2006-2011). MetS factors (obesity [body mass index {BMI} >30], diabetes mellitus [DM], hypertension [HTN], and dyslipidemia [DLD]) were tallied in each patient. For the latter 3 factors, medical treatment for the condition was used to tag a patient with the condition. Stone composition was determined by the dominant (>50%) component. Statistical analysis was designed to determine which MetS factors were independently associated with differences in stone composition. RESULTS: Five hundred ninety kidney stones were included in the analysis. Patients with MetS had a higher prevalence of uric acid stones and lower prevalence of calcium phosphate stones. HTN and DM were independently associated with differences in composition, specifically uric acid stones (higher proportion), and calcium phosphate stones (lower proportion). Obesity was not associated with differences in composition, although a secondary analysis of morbidly obese patients showed a higher proportion of uric acid stones and a lower proportion of calcium oxalate stones. CONCLUSION: HTN and DM are the MetS factors independently associated with differences in stone composition, specifically the uric acid and calcium phosphate components. Obesity has little effect on stone composition until a very high (>40) BMI is reached. The overall effect of MetS factors on stone type is relatively small, because most stones are calcium oxalate and MetS factors have little impact on calcium oxalate frequency.