Justin Friedlander

Stenting for malignant ureteral obstruction: Tandem, metal or metal‐mesh stents

Extrinsic malignant compression of the ureter is not uncommon, often refractory to decompression with conventional polymeric ureteral stents, and frequently associated with limited survival. Alternative options for decompression include tandem ureteral stents, metallic stents and metal‐mesh stents, though the preferred method remains controversial. We reviewed and updated our outcomes with tandem ureteral stents for malignant ureteral obstruction, and carried out a PubMed search using the terms “malignant ureteral obstruction,” “tandem ureteral stents,” “ipsilateral ureteral stents,” “metal ureteral stent,” “resonance stent,” “silhouette stent” and “metal mesh stent.” A comprehensive review of the literature and summary of outcomes is provided. The majority of studies encountered were retrospective with small sample sizes. The evidence is most robust for metal stents, whereas only limited data exists for tandem or metal‐mesh stents. Metal and metal‐mesh stents are considerably more expensive than tandem stenting, but the potential for less frequent stent exchanges makes them possibly cost‐effective over time. Urinary tract infections have been associated with all stent types. A wide range of failure rates has been published for all types of stents, limiting direct comparison. Metal and metal‐mesh stents show a high incidence of stent colic, migration and encrustation, whereas tandem stents appear to produce symptoms equivalent to single stents. Comparison is difficult given the limited evidence and heterogeneity of patients with malignant ureteral obstruction. It is clear that prospective, randomized studies are necessary to effectively scrutinize conventional, tandem, metallic ureteral and metal‐mesh stents for their use in malignant ureteral obstruction.

Symptom profile variability of interstitial cystitis/painful bladder syndrome by age.

Study Type – Diagnostic (symptom prevalence)

Tandem ureteral stents for the decompression of malignant and benign obstructive uropathy.

PURPOSE To evaluate the utility of two ipsilateral ureteral stents placed for benign and malignant ureteral obstruction. METHODS We performed a retrospective analysis of all cases of tandem ureteral stent (TUS) insertion at our institution from July 2007 through January 2013. Student t, Fisher exact, and log-rank test were used. RESULTS TUS insertion or exchange was performed in 187 cases. There were 66 patients (75 renal units) who underwent successful TUS insertion. Malignant ureteral obstruction (MUO) was the cause for obstruction in 39 renal units (34 patients) vs benign ureteral obstruction (BUO) in 36 renal units (32 patients). Four patients with BUO and 15 patients with MUO underwent stent exchanges at a mean 145 and 128 days, respectively. Serum creatinine levels were stable poststent placement (P=0.4). Degree of hydronephrosis improved (paired t test P<0.03) after stent placement for both benign and malignant cohorts. TUS placement was noted to fail (flank pain with worsening hydronephrosis or increasing creatinine level) in five renal units with MUO (12.8%) and none with BUO. Stent failure (either conventional or TUS) suggested worsening survival in those with MUO. Median survival for those with MUO and a history of stent failure (10 of 14 died, 71%) was 66 days compared with 432 days for those without a history of stent failure (8 of 20 died, 40%) (log-rank test P=0.007). CONCLUSION Our experience with the TUS, the largest to date, demonstrated that they are highly successful in both benign and malignant causes of obstruction, comparing favorably with metallic ureteral stents. Stent failure may be predictive for shorter survival.

Difficulties with access in percutaneous renal surgery

Percutaneous renal surgery provides a minimally invasive approach to the kidney for stone extraction in a number of different clinical scenarios. Certain clinical cases present inherent challenges to percutaneous access to the kidney. Herein, we present scenarios in which obtaining and/or maintaining percutaneous access is difficult along with techniques to overcome the challenges commonly encountered. Also, complications associated with these challenging percutaneous renal surgeries are discussed.

Obstructive Uropathy from Locally Advanced and Metastatic Prostate Cancer: An Old Problem with New Therapies

Despite stage migration to more organ-confined disease in the era of prostate-specific antigen, the complications of advanced prostate cancer are still relatively common. Urinary tract obstruction in advanced and metastatic prostate cancer can have a varied presentation, because it may occur in multiple anatomic locations at any point in the natural history of the disease. In all cases, management depends on the current stage of disease, technical feasibility of potential therapeutic interventions, and overall prognosis of the patient. This review highlights a practical approach to the evaluation, diagnosis, and management of obstructive uropathy from prostate cancer.

Predictive factors for intraoperative balloon dilation in semirigid ureteroscopic lithotripsy.

PURPOSE To analyze preoperative predictive factors for intraoperative balloon dilation in semirigid ureteroscopic lithotripsy. PATIENTS AND METHODS We retrospectively reviewed data from 397 consecutive semirigid ureteroscopic lithotripsies performed in 389 patients with ureteral stones at our institution during the calendar year 2010. Preoperative patient-related variables (age, sex, body mass index, history of urinary tract infection, previous stent placement, and time from initial presentation to intervention) and stone-related variables (laterality, numbers, location, width, and degree of hydronephrosis) were collected. Univariate analysis and multivariate logistic regression were performed to examine the statistical association between these variables and the use of intraoperative balloon ureteral dilation. RESULTS Intraoperative balloon dilation was performed in 109 (27.5%) procedures. Univariate analysis identified increasing stone width (P<0.001) and lack of previous stent placement (P<0.001) as preoperative predictors of intraoperative balloon dilation. Stone width (P<0.001, odds ratio [OR] 1.274, 95% confidence interval [CI] 1.147-1.415) and lack of previous stent placement (P<0.001, OR 0.025, CI 0.006-0.105) remained independently associated with intraoperative balloon dilation in multivariate logistic regression. CONCLUSIONS To our knowledge, our study is the first to statistically analyze the potential predictive factors for intraoperative balloon dilation in semirigid ureteroscopic lithotripsy. Larger stone width was significantly associated with intraoperative balloon dilation, whereas the presence of an indwelling ureteral stent, for at least 1 week, nearly eliminated the need for balloon dilation in subsequent ureteroscopic lithotripsy.

A Novel Transvesical Port for Natural Orifice Translumenal Endoscopic Surgery

PURPOSE To evaluate the feasibility of a novel transvesical port (TVEP) for natural orifice translumenal endoscopic surgery (NOTES) in the porcine model. MATERIALS AND METHODS The TVEP consisted of an internal guide core and external sheath design using computer-aided design software. Transvesical peritoneoscopy, renal biopsy, as well as combined transvesical/transgastric nephrectomy were performed through the TVEP in a porcine model. Operative parameters and port performance were measured. RESULTS Twelve procedures were successfully performed by four surgeons. No complications occurred with introduction of the TVEP. The mean time for placement was 5.6 minutes. Steady pressure controlled CO(2) pneumoperitoneum up to 15 mm Hg with a flow of 2 L/min was achievable. The average scoring by physician of the TVEP was 4.75 for ease of placement, 5 for ability to maintain pneumoperitoneum, 4.25 for convenience of inserting instruments, and 4.5 for overall satisfaction. The average score regarding instruments exchangeability, however, was relatively low: 3.25. CONCLUSIONS Real surgery using a novel TVEP is feasible in performing transvesical NOTES.

Sarcomatoid Squamous Cell Carcinoma of the Renal Pelvis Masquerading as Emphysematous Pyelonephritis with Staghorn Calculus

Abstract Background: Staghorn calculi are well-established risk factors for recurrent urinary tract infections (UTIs) and subsequent renal deterioration. Less commonly, long-term urothelial irritation from a calculus may also pose a risk of malignant transformation. Case Presentation: A 77-year-old male with multiple medical comorbidities presented with a chronic right renal pelvic staghorn calculus and findings concerning for emphysematous pyelonephritis. He was subsequently taken to the operating room for a planned laparoscopic right nephrectomy. Final pathology analysis revealed sarcomatoid squamous cell carcinoma (SCC) of the renal pelvis with superimposed pyelonephritis and renal abscesses. Preoperative imaging was not suggestive of malignancy. Conclusion: Although SCC of the urothelium can be caused by chronic irritation, its presentation is usually isolated to the lower urinary tract and is rarely encountered in the renal pelvis. Our patients presentation with sarcomatoid SCC is an even rarer entity. Chronic staghorn calculi must be considered as a potential risk factor for the development of both UTI and malignant urothelial transformation.

Diet and Its Role in Bladder Pain Syndrome and Comorbid Conditions

Many patients with Bladder Pain Syndrome (BPS) have sensitivities to various comestibles. There are a variety of pathologic mechanisms suggested to be responsible for the relationship between dietary intake and symptom exacerbation. Based upon the current literature, certain food types affect symptoms of BPS and comorbid conditions more than others, suggesting that a controlled method to determine dietary sensitivities, such as the elimination diet, may play an important first-line role in the management of the BPS patient. When considering dietary intervention in patients with BPS, it is of utmost importance to take into account comorbid conditions when counseling patients.

1702 NEPHROLITHOMETRY: A NOVEL SURGICAL CLASSIFICATION SYSTEM FOR RENAL STONES

INTRODUCTION AND OBJECTIVES: Percutaneous nephrolithotomy (PCNL) is the minimally invasive treatment modality for complex kidney calculi. Instruments currently available to predict PCNL outcomes are cumbersome and of limited clinical utility. We proposed a novel standardized scoring system (SS) to predict outcomes of PCNL. The SS was previously validated with 52 patients undergoing PCNL and was found to be predictive of stone free rates (SFR) and radiation time (RT). In this study we evaluated the predictive value of each variable included in the SS in a larger cohort of patients who underwent PCNL. METHODS: Five reproducible variables available from preoperative non-contrast computed tomography (CT) were measured, including stone volume (SV), stone density (SD), number of involved calyces, presence of hydronephrosis, and skin-to-stone distance (SSD). Scoring for each variable is outlined in Table 1. Comparisons of categories were made using the Wilcoxon rank sum test or KruskalWallis test. Logistic regression was used to measure the association between variables. RESULTS: A total of 137 patients were included. Demographic, clinical, and operative data are included in Table 2. SFR after first procedure was 80%. There were 18 (13.3%) complications. The most frequent complications were sepsis and bleeding. In a model predicting SFR, SV (p 0.0001), calyces (p 0.0001), greater number of calyces or staghorn calculi (SC) (p 0.0001), and pelvis involvement (p 0.004) were individually significantly associated with SFR. In a multivariable model, only SV and calyces were associated with SFR (p 0.0001). In a model predicting complications, SV (p 0.018) and SC (p 0.0318) were associated with complications. In a multivariate analysis, only SV was associated with complications (p 0.003). CONCLUSIONS: Nephrolithometry score can be used to successfully predict success of PCNL. Reproducible, standardized parameters obtained from CT can be used for preoperative patient counseling, surgical planning and for evaluation of surgical outcomes across institutions within the medical literature.