Transient ureteral obstruction after mini-percutaneous nephrolithotomy is associated with stone volume and location: results from a single-center, real-life study.

PURPOSE: To evaluate the rate of and predictors of ureteral obstruction after mini-percutaneous nephrolithotomy (mPCNL) for kidney stones. METHODS: We analyzed data from 263 consecutive patients who underwent mPCNL at a single tertiary referral academic between 01/2016 and 11/2022. Patient's demographics, stone characteristics, and operative data were collected. A nephrostomy tube was placed as the only exit strategy in each procedure. On postoperative day 2, an antegrade pyelography was performed to assess ureteral canalization. The nephrostomy tube was removed if ureteral canalization was successful. Descriptive statistics and logistic regression models were used to identify factors associated with a lack of ureteral canalization. RESULTS: Overall, median (IQR) age and stone volume were 56 (47-65) years and 1.7 (0.8-4.2) cm3, respectively. Of 263, 55 (20.9%) patients showed ureteral obstruction during pyelography. Patients without ureteral canalization had larger stone volume (p < 0.001), longer operative time (p < 0.01), and higher rate of stones in the renal pelvis (p < 0.01) than those with normal pyelography. Length of stay was longer (p < 0.01), and postoperative complications (p = 0.03) were more frequent in patients without ureteral canalization. Multivariable logistic regression analysis revealed that stone volume (OR 1.1, p = 0.02) and stone located in the renal pelvis (OR 2.2, p = 0.04) were independent predictors of transient ureteral obstruction, after accounting for operative time. CONCLUSION: One out of five patients showed transient ureteral obstruction after mPCNL. Patients with a higher stone burden and with stones in the renal pelvis are at higher risk of inadequate ureteral canalization. Internal drainage might be considered in these cases to avoid potential complications.

Vacuum-assisted mini-percutaneous nephrolithotomy is associated with lower rates of infectious complications compared to vacuum-cleaner procedure in patients at high risk for infections: a single-center experience.

PURPOSE: To evaluate the impact of vacuum-assisted mini-percutaneous nephrolithotomy (vamPCNL) vs. vacuum-cleaner mPCNL (vcmPCNL) on the rate of postoperative infectious complications in a cohort of patients with high risk factors for infections. METHODS: We retrospectively analysed data from 145 patients who underwent mPCNL between 01/2016 and 12/2022. Patient's demographics, stones characteristics and operative data were collected. vamPCNL and vcmPCNL were performed based on the surgeon's preference. High-risk patients were defied as having ≥ 2 predisposing factors for infections such as a history of previous urinary tract infections, positive urine culture before surgery, stone diameter ≥ 3 cm, diabetes mellitus and hydronephrosis. Complications were graded according to modified Clavien classification. Descriptive statistics and logistic regression models were used to identify factors associated with postoperative infectious complications. RESULTS: vamPCNL and vcmPCNL were performed in 94 (64.8%) and 51 (35.2%) cases, respectively. After surgery, infectious complications occurred in 43 (29.7%) participants. Patients who developed infectious complications had larger stone volume (p = 0.02) and higher rate of multiple stones (p = 0.01) than those who did not. Infectious complications occurred more frequently after vcmPCNL than vamPCNL (55.9% vs. 44.1%. p = 0.01) in high-risk patients. Longer operative time (p < 0.01) and length of stay (p < 0.01) were observed in cases with infectious complications. At multivariable logistic regression analysis, longer operative time (OR 1.1, p = 0.02) and vcmPCNL (OR 3.1, p = 0.03) procedures were independently associated with the risk of infectious complications post mPCNL, after accounting for stone volume. CONCLUSION: One out of three high-risk patients showed infectious complications after mPCNL. vamPCL and shorter operative time were independent protective factors for infections after surgery.

Prevalence and predictors of stone passage after double J stenting for symptomatic ureteral stones: a cross-sectional, real-life study.

PURPOSE: To evaluate the rate of and predictors of stone passage (SP) after urgent retrograde stenting for symptomatic ureteral stones. METHODS: We retrospectively analysed data from 249 consecutive patients presenting to the emergency department for symptomatic ureteral stones and treated with retrograde stenting. Demographic, clinical and laboratory characteristics were collected. Stones parameters were collected before stenting and SP was evaluated at 1 month with computerized tomography. Descriptive statistics and logistic regression models tested the association between predictors and SP. RESULTS: Overall, median (IQR) age and stone diameter were 56 (45-68) years and 7.1 (4.4-9.8) mm, respectively. Stones were located in the proximal, mid and distal ureter in 102 (41.0%), 48 (19.3%) and 99 (39.8%) cases. SP was observed in 65 (26.2%) individuals. Stone diameter (3.2 vs. 7.7 mm, p < 0.001) and stone density (416 vs. 741, p < 0.001) were lower and a higher rate of distal stones (76.9% vs. 26.7%, p < 0.001) was found in the SP group compared to that with persistent stones. Multivariable logistic regression analysis showed that distal ureteral stone location (OR 7.9, p < 0.01) and lower HU (OR 0.9, p < 0.01) were associated with SP, after accounting for stone volume. Patients with a distal stone of 500 HU had a 75% probability of SP. CONCLUSION: Stone passage occurred in 26% of patients with indwelling stent due to symptomatic ureteral stones. Lower stone density and distal stone location were independent predictors of stone passage. Patients with these criteria should be managed with follow-up imaging and stent removal instead of ureteroscopy.

Perioperative and Survival Outcomes of Patients Treated With Robot-Assisted Partial Nephrectomy and Percutaneous Microwave Ablation for Small Renal Masses: A Single Center Experience.

BACKGROUND: Robot assisted partial nephrectomy (RAPN) and microwave ablation (MWA) are 2 of the most advanced techniques for the management of localized small renal masses. PURPOSE: To compare the perioperative, functional and oncological results of RAPN and MWA. MATERIALS AND METHODS: Data from 171 consecutive patients undergoing either RAPN or MWA for a localized small renal mass at a single academic center was retrospectively collected. Baseline features included patients' demographics and masses' characteristics. Procedures were compared in terms of perioperative outcomes and renal function variation Progression of a persistent lesion or local recurrence after a complete treatment defined local tumor progression. Descriptive statistics and survival analysis tested the association between predictors and local tumor progression. RESULTS: Of all, 109 and 62 patients underwent RAPN and MWA. Patients in the MWA group were older (P = .002) had higher Charlson Comorbidity Index (CCI) (P < .001) and higher frequency of preoperative chronic kidney disease (P < .001). MWA led to a shorter postoperative hospitalization time (P < .001) and lower incidence of medical complications (6.5% vs. 22.9%, P = .02) than RAPN. GFR decline was similar between groups both at discharge (P = .39) and at the time of last follow up (P = 1.00). A lower rate of secondary interventions (11.7% vs. 2.8%, P = .037) and a better disease-free survival (83.2% vs. 96.5%, P = .027) were reported after RAPN. Conversely, cancer specific and overall survival were comparable (P > .05). At univariate regression analysis, MWA was associated with local tumor progression (HR 3.46, P = .040). CONCLUSION: MWA displayed a lower perioperative impact, while functional outcomes were similar after each intervention. RAPN resulted superior in terms of tumor eradication, but no difference was noted regarding cancer specific survival. Thus, MWA represents a valid alternative in frail patients, though less radical than RAPN.

Thermal ablation for small renal masses: Identifying the most appropriate tumor size cut-off for predicting perioperative and oncological outcomes.

OBJECTIVES: To test TRIFECTA achievement [1) absence of CLAVIEN-DINDO ≥3 complications; 2) complete ablation; 3) absence of ≥30% decrease in eGFR] and local recurrence rates, according to tumor size, in patients treated with thermal ablation (TA: radiofrequency [RFA] and microwave ablation [MWA]) for small renal masses. METHODS: Retrospective analysis (2008-2020) of 432 patients treated with TA (RFA: 162 vs. MWA: 270). Tumor size was evaluated as: 1) continuously coded variable (cm); 2) tumor size strata (0.1-2 vs. 2.1-3 vs. 3.1-4 vs. >4 cm). Multivariable logistic regression models and a minimum P-value approach were used for testing TRIFECTA achievement. Kaplan-Meier plots depicted local recurrence rates over time. RESULTS: Overall, 162 (37.5%) vs. 140 (32.4%) vs. 82 (19.0%) vs. 48 (11.1%) patients harboured, respectively, 0.1 to 2 vs. 2.1 to 3 vs. 3.1 to 4 vs. >4 cm tumors. In multivariable logistic regression models, increasing tumor size was associated with higher rates of no TRIFECTA achievement (OR:1.11; P< 0.001). Using a minimum P-value approach, an optimal tumor size cut-off of 3.2 cm was identified (P< 0.001). In multivariable logistic regression models, 3.1 to 4 cm tumors (OR:1.27; P< 0.001) and >4 cm tumors (OR:1.49; P< 0.001), but not 2.1 to 3 cm tumors (OR:1.05; P= 0.3) were associated with higher rates of no TRIFECTA achievement, relative to 0.1 to 2 cm tumors. The same results were observed in separate analyses of RFA vs. MWA patients. After a median (IQR) follow-up time of 22 (12-44) months, 8 (4.9%), 8 (5.7%), 11 (13.4%), and 5 (10.4%) local recurrences were observed in tumors sized 0.1 to 2 vs. 2.1 to 3 vs. 3.1 to 4 vs. >4 cm, respectively (P= 0.01). CONCLUSION: A tumor size cut-off value of ≤3 cm is associated with higher rates of TRIFECTA achievement and lower rates of local recurrence over time in patients treated with TA for small renal masses.

Predictive clinico-pathological factors to identify BCG, unresponsive patients, after re-resection for T1 high grade non-muscle invasive bladder cancer.

INTRODUCTION: Seventy-five percent of bladder cancers are non-muscle invasive. The treatment strategy includes the transurethral resection of bladder tumor (TURB) followed by intravesical immunotherapy with the bacillus of Calmette-Guerin (BCG) or chemotherapy, depending on the grade of bladder tumor. Despite a proper BCG intravesical instillations schedule, up to 40% of patients present a failure within 2 years. The aim of this retrospective study was to investigate the predictive factors in the response to BCG in patients with a high-grade non-muscle invasive bladder cancer diagnosis. MATERIALS AND METHODS: Patients with non-muscle invasive bladder cancer from 13 hospitals and academic institutions were identified and treated, from January 1, 2002, until December 31, 2012, with TURB and a subsequent re-TURB for restaging before receiving BCG. Follow-up was performed with urine cytology and cystoscopy every 3 months for 1 year and, successively every 6 months. Univariate and multivariate Cox regression models addressed the response to BCG therapy. Kaplan-Meier overall survival (OS) and cancer-specific survival (CSS) estimates were determined for BCG responsive vs. BCG unresponsive patients. RESULTS: A total of 1,228 patients with non-muscle invasive bladder cancer were enrolled. Of 257 (20.9%) patients were BCG unresponsive. Independent predictive factors for response to BCG were: multifocality (HR: 1.4; 95% CI 1.05-1.86; P = 0.019), lymphovascular invasion (HR: 1.75; 95% CI 1.22-2.49; P = 0.002) and high-grade on re-TURB (HR: 1.39; 95% CI 1.02-1.91; P = 0.037). Overall survival was significantly reduced in BCG-unresponsive patients compared to BCG-responsive patients at 5 years (82.9% vs. 92.4%, P < 0.0001) and at 10 years (44.2% vs. 74.4%, P < 0.0001). Similarly, cancer-specific survival was reduced in BCG-unresponsive patients at 5 years (90.6% vs. 97.3%, P < 0.0001) and at 10 years (72.3% vs. 87.2%, P < 0.0001). CONCLUSION: Multifocality, lymphovascular invasion, and high-grade on re-TURB were independent predictors for response to BCG treatment. BCG-unresponsive patients reported worse oncological outcomes.