New modalities for evaluation and surveillance of complex renal cysts.

PURPOSE: The increased use of abdominal imaging has led to more frequent detection of incidental renal cysts. Since the inception of the Bosniak classification system, management of Bosniak I, III and IV cysts has been clearly defined, while evaluation and management of Bosniak II and IIF cysts have remained a clinical dilemma. Discussions of new imaging modalities are becoming increasingly prevalent in the radiological literature. In this context we performed a comprehensive review of the recent literature on complex renal cysts focusing on new imaging modalities, surveillance strategies and biopsy. MATERIALS AND METHODS: We performed a comprehensive literature review of articles published from January 1, 1998 through December 31, 2013 via MEDLINE(®), EMBASE and the Cochrane Collection using a predetermined search strategy. All studies included were performed in humans older than 18 years, were written in English and had an abstract available for review. We grouped studies into 1 of 5 categories, ie computerized tomography, magnetic resonance imaging, ultrasound, biopsy and surveillance. RESULTS: While computerized tomography and magnetic resonance imaging with and without contrast enhancement remain the gold standard to evaluate cystic lesions of the kidney, diffusion-weighted magnetic resonance imaging and contrast enhanced ultrasound have surfaced as new tools for assessment of complex cysts. Comparative effectiveness studies on these new imaging modalities are limited. Image guided biopsy has increasingly been shown to be useful for evaluation of intermediate (Bosniak II and IIF) complex cysts. We found few studies providing guidance on the duration and/or intensity of surveillance required for intermediate complex renal cysts. CONCLUSIONS: Although new and enhanced techniques are in development and may be useful in the future management of complex renal cysts, there is a paucity of data regarding the value of these new techniques. Future research should focus on surveillance of intermediate complex renal cysts, particularly on the ideal frequency and type of imaging required.

Five-year experience with metallic stents for chronic ureteral obstruction.

PURPOSE: We present 5 years of outcome data on metallic ureteral stents in a cohort of patients treated for chronic ureteral obstruction. MATERIALS AND METHODS: We retrospectively identified and analyzed the records of all patients in whom a Resonance® Metallic Ureteral Stent was placed between early 2007 and late 2011 at our institution. We performed a descriptive analysis of key outcomes, including the failure and death rates, and stenting duration, defined as the time from initial stent placement to last stent failure or patient death. We also performed a secondary comparative analysis of patients with a benign vs malignant etiology of obstruction. RESULTS: A total of 139 metallic stents were placed in 47 patients, including 27 (57%) with malignant and 20 (43%) with a benign etiology. Of the patients 15 (32%) had bilateral obstruction. Maximum followup was 59 months (mean 20, median 13, IQR 4-31). Stent failure occurred in 13 patients (28%), including 4 in the benign and 9 in the malignant group (p = 0.35). The median duration of stenting for benign and malignant obstruction was 22 (IQR 9-39) vs 7 months (IQR 3-25) (p = 0.106). Stenting duration was equivalent when controlling for the higher death rate in the malignant group. CONCLUSIONS: Resonance metallic stents are an adequate management strategy for benign and malignant ureteral obstruction. A subset of patients in each group continued to do well at more than a 3-year overall duration of stenting. Failure rates were similar for benign and malignant etiologies.

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.

Robot-assisted radical prostatectomy in men aged > or =70 years.

OBJECTIVES: To assess the outcomes of elderly men with prostate cancer treated with robot-assisted radical prostatectomy (RARP), because more healthy elderly men will present with localized prostate cancer and many will seek surgical treatment as the population ages. PATIENTS AND METHODS: Between 2005 and 2008, 203 men had RARP performed by one surgeon; patients were categorized into two groups based on their age (> or =70 vs <70 years). All data were recorded prospectively in an institutional approved database. RESULTS: Of the 203 men, 23 (11%) were aged > or =70 years; the older men had similar baseline characteristics as younger men, and had characteristics during and after surgery comparable to those in younger men. The pathological RARP Gleason grade was significantly greater in older men. Surgical complications were not significantly different between the groups. Continence rates were significantly lower in older men at 6 months after surgery, but returned to levels equivalent to those in younger men within 12 months after surgery. Older patients took significantly longer to be capable of driving after surgery. CONCLUSIONS: The outcomes of RARP in elderly men are largely comparable to those in younger men, with the exception of higher pathological Gleason grade, a transient delay in return of continence, and taking longer to return to driving after surgery. Advanced chronological age should not be a contraindication for RARP in patients with clinically localized prostate cancer, but expectations should be managed preoperatively.

PLK-1 Silencing in Bladder Cancer by siRNA Delivered With Exosomes.

OBJECTIVE: To use exosomes as a vector to deliver small interfering ribonucleic acid (siRNA) to silence the polo-like kinase 1 (PLK-1) gene in bladder cancer cells. MATERIALS AND METHODS: Exosomes were isolated from both human embryonic kidney 293 (HEK293) cell and mesenchymal stem cell (MSC) conditioned media. Fluorescently labeled exosomes were co-cultured with bladder cancer and normal epithelial cells and uptake was quantified by image cytometry. PLK-1 siRNA and negative control siRNA were loaded into HEK293 and MSC exosomes using electroporation. An invasive bladder cancer cell line (UMUC3) was co-cultured with the electroporated exosomes. Quantitative reverse transcriptase polymerase chain reaction was performed. Protein analysis was performed by Western blot. Annexin V staining and MTT assays were used to investigate effects on apoptosis and viability. RESULTS: Bladder cancer cell lines internalize an increased percentage of HEK293 exosomes when compared to normal bladder epithelial cells. Treatment of UMUC3 cells with exosomes electroporated with PLK-1 siRNA achieved successful knockdown of PLK-1 mRNA and protein when compared to cells treated with negative control exosomes. CONCLUSION: HEK293 and MSC exosomes were effectively used as a delivery vector to transport PLK-1 siRNA to bladder cancer cells in vitro, resulting in selective gene silencing of PLK-1. The use of exosomes as a delivery vector for potential intravesical therapy is attractive.

Effect of renal function on urinary mineral excretion and stone composition.

OBJECTIVE: To determine the effect of renal function on urinary mineral stone excretion and composition of kidney stones in patients undergoing urologic intervention for nephrolithiasis. METHODS: We performed a retrospective analysis of 158 patients with 193 kidney stones who underwent endourologic intervention for nephrolithiasis. The patients were grouped by the estimated glomerular filtration rate (eGFR). The kidney stone composition and results of the 24-hour urinalysis were reported for each group. Statistical analysis was performed using the chi-square test, Kruskal-Wallis test, and analysis of variance. RESULTS: The kidney stone composition profile differed significantly between the groups, with uric acid stones associated with a lower eGFR and calcium phosphate stones associated with a greater eGFR. A lower eGFR correlated with lower urine pH, lower calcium excretion, and greater oxalate excretion. Excretion of uric acid and the body mass index did not differ between groups. CONCLUSION: Different degrees of renal function correlated with certain types of kidney stones. The urine pH was lower in patients with impaired renal function. Renal function might be an underappreciated factor that affects kidney stone composition and urinary mineral excretion.

Impact of prostate median lobe anatomy on robotic-assisted laparoscopic prostatectomy.

OBJECTIVES: Robotic-assisted laparoscopic prostatectomy (RALP) is becoming widely used for the management of prostate cancer. Although prostate size does not affect operative times for RALP, the effect of a large median prostate lobe has not been described. METHODS: One hundred fifty-four men underwent RALP by one surgeon between 2005 and 2007. Patients were categorized into 2 groups based on the presence or absence of a large median prostate lobe identified during RALP. The RALP was divided into sections from bladder mobilization to vesicourethral anastomosis. Operative times and outcomes were recorded prospectively. RESULTS: Of the 154 patients, 29 (18%) of the men had large median prostate lobes. Men with large median lobes were slightly older, but had similar prostate-specific antigen, body mass index, clinical and pathologic stage, biopsy and prostatectomy Gleason grade, tumor volumes, and surgical margin rate compared with men without median lobes. Yet, prostate weight, estimated blood loss, and hospital stay was significantly greater in men with large median lobes. The overall operative time for the RALP was greater in men with a large median lobe caused by an increased time required for posterior bladder neck and seminal vesicle dissection. There was no difference in complications such as urine leaks, bladder neck contractures, and migration of Hem-o-lok clips into the bladder. Continence at 3 and 6 months after RALP were not significantly different in men with large median lobes. CONCLUSIONS: Despite equivalent oncological outcomes, we demonstrate a significant increase in operative times among men with large median lobes.

Outcomes of locally advanced (T3 or greater) prostate cancer in men undergoing robot-assisted laparoscopic prostatectomy.

OBJECTIVES: Despite nearly equivalent outcomes between open and robot-assisted laparoscopic prostatectomy (RALP) for organ-confined prostate cancer (PCa), the role of primary treatment with RALP in men with locally advanced (T3 or greater) PCa has not been described in detail. We report our experience with RALP for pathologically advanced disease. PATIENTS AND METHODS: From October 2005 to November 2008, 220 RALPs were performed by a single surgeon (R.B.N.). Outcomes were assessed prospectively in an institutional review board-approved database. RESULTS: Of 220 RALPs, 35 (15.9%) were performed for pT3 PCa; none of them were identified preoperatively. There was no difference in operative time compared with patients with pT2 disease (271 vs. 295 minutes, p = 0.09). The positive surgical margin (PSM) rate was 20% compared with 4.9% for pT2 (p = 0.004). Sural nerve grafts were performed in 20%, and 57% had bilateral nerve sparing. The use of bilateral or unilateral nerve sparing was not associated with increased PSM (p = 0.85). Biochemical recurrence occurred in 28.6% of men with pT3 disease over an average of 13 months of follow-up time, 30% of which occurred in men with a PSM. At 6 months, an 85% continence rate was achieved, and at 1 year continence was 100% for pT3. Compared with pT2, men with advanced disease had similar recovery after RALP based on postsurgery questionnaires. CONCLUSIONS: RALP is a feasible approach to patients with pathologically advanced PCa as 71% were without evidence of disease at 13 months postoperatively. PSM rate (20%) is comparable to previously reported open PSM rates (24-66%).

Application of continuous tension to aid in performing the vesicourethral anastomosis for robot-assisted prostatectomy.

OBJECTIVES: Approximation of the bladder to urethra during robot-assisted laparoscopic prostatectomy (RALP) is a critical step toward achieving long-term continence. To determine the impact on surgical outcomes after RALP, we compare two techniques for constructing the vesicourethral anastomosis. METHODS: One hundred fifty-four men underwent RALP by one surgeon between 2005 and 2007. The vesicourethral anastomosis was performed in a standard Van Velthoven fashion for the first 61 patients. The anastomosis in the remaining 93 patients was performed in a running fashion with the sutures under continuous tension applied by the surgical assistant and the third robotic arm. Operative times and surgical outcomes were recorded prospectively. RESULTS: When comparing standard Van Velthoven to continuous tension anastomosis, we demonstrate equivalent oncologic outcomes, continence and time required for the anastomosis. Yet, the frequency of complications related to the anastomotic technique, such as urine leaks, bladder neck contractures and migrated hemo-lock clips, were significantly lower with the continuous tension technique compared to the standard Van Velthoven running anastomosis. CONCLUSIONS: Performing the vesicourethral anastomosis under continuous tension demonstrated improved outcomes compared to the Van Velthoven anastomosis by allowing persistent close apposition of the bladder to urethra. Additionally, the learning curve associated with implementation of a new anastomotic technique was negligible.