Yonsei nomogram: A predictive model of new-onset chronic kidney disease after on-clamp partial nephrectomy in patients with T1 renal tumors.

OBJECTIVES: To develop a predictive nomogram for chronic kidney disease-free survival probability in the long term after partial nephrectomy. METHODS: A retrospective analysis was carried out of 698 patients with T1 renal tumors undergoing partial nephrectomy at a tertiary academic institution. A multivariable Cox regression analysis was carried out based on parameters proven to have an impact on postoperative renal function. Patients with incomplete data, <12 months follow up and preoperative chronic kidney disease stage III or greater were excluded. The study end-points were to identify independent risk factors for new-onset chronic kidney disease development, as well as to construct a predictive model for chronic kidney disease-free survival probability after partial nephrectomy. RESULTS: The median age was 52 years, median tumor size was 2.5 cm and mean warm ischemia time was 28 min. A total of 91 patients (13.1%) developed new-onset chronic kidney disease at a median follow up of 60 months. The chronic kidney disease-free survival rates at 1, 3, 5 and 10 year were 97.1%, 94.4%, 85.3% and 70.6%, respectively. On multivariable Cox regression analysis, age (1.041, P = 0.001), male sex (hazard ratio 1.653, P < 0.001), diabetes mellitus (hazard ratio 1.921, P = 0.046), tumor size (hazard ratio 1.331, P < 0.001) and preoperative estimated glomerular filtration rate (hazard ratio 0.937, P < 0.001) were independent predictors for new-onset chronic kidney disease. The C-index for chronic kidney disease-free survival was 0.853 (95% confidence interval 0.815-0.895). CONCLUSION: We developed a novel nomogram for predicting the 5-year chronic kidney disease-free survival probability after on-clamp partial nephrectomy. This model might have an important role in partial nephrectomy decision-making and follow-up plan after surgery. External validation of our nomogram in a larger cohort of patients should be considered.

Prostate-specific antigen 10-20 ng/mL: A predictor of degree of upgrading to ≥8 among patients with biopsy Gleason score 6.

PURPOSE: This study aimed to identify the predictors of upgrading and degree of upgrading among patients who have initial Gleason score (GS) 6 treated with robot-assisted radical prostatectomy (RARP). MATERIALS AND METHODS: A retrospective review of the data of 359 men with an initial biopsy GS 6, localized prostate cancer who underwent RARP between July 2005 to June 2010 was performed. They were grouped into group 1 (nonupgrade) and group 2 (upgraded) based on their prostatectomy specimen GS. Logistic regression analysis of studied cases identified significant predictors of upgrading and the degree of upgrading after RARP. RESULTS: The mean age and prostate-specific antigen (PSA) was 63±7.5 years, 8.9±8.77 ng/mL, respectively. Median follow-up was 59 months (interquartile range, 47-70 months). On multivariable analysis, age, PSA, PSA density and ≥2 cores positive were predictors of upgrading with (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01-1.06; p=0.003; OR, 1.006; 95% CI, 1.01-1.11; p=0.018; OR, 0.65; 95% CI, 0.43-0.98, p=0.04), respectively. On subanalysis, only PSA level of 10-20 ng/mL is associated with upgrading into GS ≥8. They also had lower biochemical recurrence free survival, cancer specific survival, and overall survival (p≤0.001, p=0.003, and p=0.01, respectively). CONCLUSIONS: Gleason score 6 patients with PSA (10-20 ng/mL) have an increased risk of upgrading to pathologic GS (≥8), subsequently poorer oncological outcome thus require a stricter follow-up. These patients should be carefully counseled in making an optimal treatment decision.

The effectiveness and safety of percutaneous nephrolithotomy (PCNL) for solitary kidneys: A single-center experience

OBJECTIVE: To evaluate the outcomes of percutaneous nephrolithotomy in patients with solitary kidneys. METHODOLOGY: Between January 2009 and December 2013, 31 patients with renal stones in solitary kidneys were treated with PCNL. All stones were diagnosed using an unenhanced CT scan. The solitary functioning status of the kidney was congenital absence of the contralateral kidney in 7(22%); opposite nephrectomy in 15(48%); and nonfunctional contralateral kidneys in 9(29%) as detected by nuclear scintigraphy. The serum creatinine and hemoglobin were monitored at regular intervals. The stones were classified using the Guy Stone Score while the complications were analyzed using the Clavien-Dindo Grading System. The mean follow-up in months was 21.3±12.26 (4-48). RESULTS: The male to female ratio is 1.2:1. According to the Guy Stone Score, the stones were Grade 1 in 54.8% (17/31), Grade 2 in 16.1% (5/31), Grade 3 in 6.4% (2/31) and Grade 4 in 22.5% patients, respectively. The stone-free status was determined with a postop CT scan. Complete stone clearance was achieved in 90.3% (28/31) after a single session of PCNL. The mean operative time was 151±36.7(90-230) minutes. According to the Clavien-Dindo Classification, 19 (59.3%) had no complication, 4 (12.9%) had Grade 1 (fever), 7 (29.2%) had Grade 2 (blood transfusion) and 1(3%) had Grade 5 (postoperative hemodialysis, sepsis and death). The rest had stable or improved renal function without postoperative hemodialysis. The mean rise in serum creatinine was 0.67±1.01 (0.1-3.5) mg/dL. Mean drop in hemoglobin was 1.6±0.89(0.5-3.8) gm/dL. CONCLUSION: PCNL is effective and safe for patients with nephrolithiasis in solitary kidneys. This minimally invasive procedure achieves a high stone clearance rate with acceptably low morbidity and mortality.