Predictors of Postoperative Urinary Incontinence After Holmium Laser Enucleation of the Prostate: 12 Months Follow-Up.

OBJECTIVE: To identify pre- and perioperative factors associated with incontinence after holmium laser enucleation of the prostate for benign prostatic hyperplasia. METHODS: Retrospective review of our single-surgeon database identified 88 patients with 12 months' follow-up who underwent surgery between December 2014 and November 2016. Postoperative urinary incontinence was defined as 1 or more pads per day. Patients were evaluated at 6 weeks, 6 months, and 12 months postoperatively. RESULTS: Preoperative variables associated with incontinence at all follow-ups included pre-existing incontinence and higher detrusor voiding pressure. Higher maximum urinary flow and lower postvoid residual were predictors of transient urinary incontinence. On multivariate analysis, pre-existing incontinence remained significant as a 12-month predictor, whereas a higher detrusor voiding pressure was only significant as a 6-week predictor. De novo incontinence at 12 months was identified in only 1/44 patients (2%). Among patients with pre-existing incontinence, 30/40 (75%) reported resolution of their incontinence at 12 months. Numerous demographic, urinary, urodynamic, and operative factors were not significant for predicting incontinence. The mean decrease in pads per day between 6 weeks and 6 months was -1.6 and between 6 months and 12 months was -0.75. Medical management did not significantly impact rates of postoperative incontinence when compared to observation alone. CONCLUSION: Pre-existing urinary incontinence and/or higher detrusor voiding pressure may predict urinary incontinence 12 months after holmium laser enucleation of the prostate.

Sensitivity of Noncontrast Computed Tomography for Small Renal Calculi With Endoscopy as the Gold Standard.

OBJECTIVE: To compare the sensitivity of noncontrast computed tomography (CT) with endoscopy for detection of renal calculi. Imaging modalities for detection of nephrolithiasis have centered on abdominal x-ray, ultrasound, and noncontrast CT. Sensitivities of 58%-62% (abdominal x-ray), 45% (ultrasound), and 95%-100% (CT) have been previously reported. However, these results have never been correlated with endoscopic findings. METHODS: Idiopathic calcium oxalate stone formers with symptomatic calculi requiring ureteroscopy were studied. At the time of surgery, the number and the location of all calculi within the kidney were recorded followed by basket retrieval. Each calculus was measured and sent for micro-CT and infrared spectrophotometry. All CT scans were reviewed by the same genitourinary radiologist who was blinded to the endoscopic findings. The radiologist reported on the number, location, and size of each calculus. RESULTS: Eighteen renal units were studied in 11 patients. Average time from CT scan to ureteroscopy was 28.6 days. The mean number of calculi identified per kidney was 9.2 ± 6.1 for endoscopy and 5.9 ± 4.1 for CT (P <.004). The mean size of total renal calculi (sum of the longest stone diameters) per kidney was 22.4 ± 17.1 mm and 18.2 ± 13.2 mm for endoscopy and CT, respectively (P = .06). CONCLUSION: CT scan underreports the number of renal calculi, probably missing some small stones and being unable to distinguish those lying in close proximity to one another. However, the total stone burden seen by CT is, on average, accurate when compared with that found on endoscopic examination.

Addition of Sodium Bicarbonate to Irrigation Solution May Assist in Dissolution of Uric Acid Fragments During Ureteroscopy.

INTRODUCTION: We hypothesized that adding sodium bicarbonate (bicarb) to normal saline (NS) irrigation during ureteroscopy in patients with uric acid (UA) nephrolithiasis may assist in dissolving small stone fragments produced during laser lithotripsy. In vitro testing was performed to determine whether dissolution of UA fragments could be accomplished within 1 hour. MATERIALS AND METHODS: In total 100% UA renal calculi were fragmented, filtered, and separated by size. Fragment sizes were <0.5 mm and 0.5 to 1 mm. Similar amounts of stone material were agitated in solution at room temperature. Four solutions were tested (NS, NS +1 ampule bicarb/L, NS +2, NS +3). Both groups were filtered to remove solutions after fixed periods. Filtered specimens were dried and weighed. Fragment dissolution rates were calculated as percent removed per hour. Additional testing was performed to determine whether increasing the temperature of solution affected dissolution rates. RESULTS: For fragments <0.5 mm, adding 2 or 3 bicarb ampules/L NS produced a dissolution rate averaging 91% ± 29% per hour. This rate averaged 226% faster than NS alone. With fragments 0.5 to 1 mm, addition of 2 or 3 bicarb ampules/L NS yielded a dissolution rate averaging 22% ± 7% per hour, which was nearly five times higher than NS alone. There was a trend for an increase in mean dissolution rate with higher temperature but this increase was not significant (p = 0.30). CONCLUSIONS: The addition of bicarbonate to NS more than doubles the dissolution rate of UA stone fragments and fragments less than 0.5 mm can be completely dissolved within 1 hour. Addition of bicarb to NS irrigation is a simple and inexpensive approach that may assist in the dissolution of UA fragments produced during ureteroscopic laser lithotripsy. Further studies are needed to determine whether a clinical benefit exists.

A Survey Regarding Preference in the Management of Bilateral Stone Disease and a Comparison of Clavien Complication Rates in Bilateral vs Unilateral Percutaneous Nephrolithotomy.

OBJECTIVE: To discuss complications of simultaneous bilateral percutaneous nephrolithotomy (SB-PCNL) when compared with unilateral percutaneous nephrolithotomy and survey surgeon preference in bilateral stone disease management. PATIENTS AND METHODS: A database of all participating percutaneous nephrolithotomy (PCNL) patients who underwent treatment at Indiana University Health Methodist Hospital within a 10-year period from 2006 to 2015 by a single surgeon (JL) was utilized. Perioperative data, as well as complications, defined according to the Clavien grading system, were recorded. A survey of members of the Endourological Society was performed regarding surgical management in the setting of bilateral stone disease. RESULTS: A total of 563 patients were identified over the study period with 129 undergoing SB-PCNL. Overall, SB-PCNL patients had a longer procedure (176.9 vs 115.6 minutes, P <.0001), were more likely to undergo a secondary procedure (73% vs 44, P <.001), and had a longer hospital stay (3.2 vs 2.3 days, P <.001). Notably, there were no differences in the number or the severity of complications between the 2 groups. A total of 153 endourologists completed the survey. Of these endourologists, 58 (38%) performed bilateral PCNL under anesthesia. The top reasons for electing not to perform bilateral PCNLs included the duration of bilateral procedures (53%), bilateral renal injury (48%), and rare performance of bilateral surgery (35%). CONCLUSION: Although the procedure length was longer in the SB-PCNL group, there were similar rates of complications and severity between unilateral PCNL and SB-PCNL. A majority of endourologists surveyed do not perform bilateral PCNL but would perform bilateral ureteroscopy with the duration of the procedure and concern for bilateral renal injury representing the most common reasons.

Preoperative Bladder Urine Culture as a Predictor of Intraoperative Stone Culture Results: Clinical Implications and Relationship to Stone Composition.

PURPOSE: We examine the relationship between urine and stone cultures in a large cohort of patients undergoing percutaneous stone removal and compare the findings in infectious vs metabolic calculi. MATERIALS AND METHODS: A total of 776 patients treated with percutaneous nephrolithotomy who had preoperative urine cultures and intraoperative stone cultures were included in the study. Statistical analysis used chi-square or logistic fit analysis as appropriate. RESULTS: Preoperative urine culture was positive in 352 patients (45.4%) and stone cultures were positive in 300 patients (38.7%). There were 75 patients (9.7%) with negative preoperative cultures who had positive stone cultures, and in patients with both cultures positive the organisms differed in 103 (13.3%). Gram-positive organisms predominated in preoperative urine and stone cultures. CONCLUSIONS: Preoperative urine cultures in patients undergoing percutaneous nephrolithotomy are unreliable as there is a discordance with intraoperative stone cultures in almost a quarter of cases. There has been a notable shift toward gram-positive organisms in this cohort of patients.

A Proposed Grading System to Standardize the Description of Renal Papillary Appearance at the Time of Endoscopy in Patients with Nephrolithiasis.

BACKGROUND AND PURPOSE: The appearance of the renal papillae in patients with nephrolithiasis can be quite variable and can range from entirely healthy to markedly diseased. The implications of such findings remain unknown. One potential reason is the lack of a standardized system to describe such features. We propose a novel grading scale to describe papillary appearance at the time of renal endoscopy. METHODS: Comprehensive endoscopic renal assessment and mapping were performed on more than 300 patients with nephrolithiasis. Recurring abnormal papillary characteristics were identified and quantified based on degree of severity. RESULTS: Four unique papillary features were chosen for inclusion in the PPLA scoring system- ductal Plugging, Pitting, Loss of contour, and Amount of Randall's plaque. Unique scores are calculated for individual papillae based on reference examples. CONCLUSIONS: The description and study of renal papillary appearance in stone formers have considerable potential as both a clinical and research tool; however, a standardized grading system is necessary before using it for these purposes.

Wolf Piranha Versus Lumenis VersaCut Prostate Morcellation Devices: A Prospective Randomized Trial.

PURPOSE: Holmium laser enucleation of the prostate for the management of benign prostatic hyperplasia involves the 2 steps of enucleation and morcellation. Few prostate morcellation devices are available. In this study we compare the Wolf Piranha and Lumenis® VersaCut™ prostate morcellation devices. MATERIALS AND METHODS: After institutional review board approval and patient informed consent, a prospective, randomized trial was initiated for patients with symptomatic benign prostatic hyperplasia undergoing holmium laser enucleation of the prostate. All procedures were performed by a single surgeon (JEL) at Indiana University Health Methodist Hospital using the Piranha or VersaCut prostate morcellation device. Patient demographics, and preoperative, intraoperative and postoperative data for patients in the 2 treatment groups were analyzed and compared in a prospective fashion. RESULTS: A total of 74 patients were enrolled and randomized for the treatment device. Both groups were comparable in terms of age, prostate specific antigen and prostate size. There was no difference in patient demographic and preoperative characteristics. The Piranha achieved a slightly higher morcellation rate at 5.6 gm per minute (range 1.4 to 18), compared to the VersaCut at 4.8 gm per minute (range 1.3 to 9.5). However, the difference was not statistically significant (p = 0.14). Cost analysis (USD per patient) favored the VersaCut ($241 vs $471, p <0.001). CONCLUSIONS: Morcellation rates for the Piranha and VersaCut prostate morcellation devices are comparable, with the Piranha having a statistically significant increased cost. The Wolf Piranha also has a more complicated design, making it less user-friendly for the operating room staff and, therefore, more difficult to troubleshoot than the Lumenis VersaCut. Nevertheless, 75% of urology faculty, fellows and residents preferred the Piranha over the VersaCut, reporting that when working properly, it was more efficient in tissue removal.

Initial Experience and Comparative Efficacy of the UreTron: A New Intracorporeal Ultrasonic Lithotriptor.

OBJECTIVE: To describe the initial clinical experience with the UreTron (Med-Sonics, Erie, PA), a new ultrasonic lithotriptor. Historically, ultrasound-only intracorporeal lithotriptors have been considered the gold standard for stone removal during percutaneous nephrolithotomy. Recently, they have lost favor to newer dual and combination devices believed by many to be more efficient. The UreTron features patented technology to precisely control probe vibration and achieve more efficient output potentially improving efficiency of stone clearance. To date, the clinical efficacy of this new device has yet to be tested relative to alternative state-of-the-art lithotriptors. METHODS: Thirty-one patients with renal stones >2 cm undergoing percutaneous nephrolithotomy were studied. All cases were performed by the same surgeon, and data were recorded prospectively using the same protocol established for a separate ongoing comparison study designed to assess performance of 3 separate state-of-the-art lithotriptors (CyberWand, StoneBreaker, and LithoClast Select). Bivariate analysis was performed between the UreTron cohort and the combined cohort of the alternative state-of-the-art lithotriptors (n = 51). RESULTS: The UreTron achieved the highest stone clearance rate (51.9 mm(2)/min) of any device. It also had little decrease in clearance efficiency when used on "hard" stones (48.5 mm(2)/min). The UreTron had a faster clearance rate than the alternative lithotriptor cohort (51.9 vs 36.0 mm(2)/min; P = .02) with no differences in stone-free rate, secondary procedures, clinical complications, or device malfunctions (P >.05). CONCLUSION: The UreTron compares favorably with alternative state-of-the-art intracorporeal lithotriptors with faster stone clearance rates and equivalent clinical outcomes.

Nephrocalcinosis in Calcium Stone Formers Who Do Not have Systemic Disease.

PURPOSE: Nephrocalcinosis is commonly present in primary hyperparathyroidism, distal renal tubular acidosis and medullary sponge kidney disease. To our knowledge it has not been studied in patients with calcium phosphate stones who do not have systemic disease. MATERIALS AND METHODS: We studied patients undergoing percutaneous nephrolithotomy who had calcium phosphate or calcium oxalate stones and did not have hyperparathyroidism, distal renal tubular acidosis or medullary sponge kidney disease. On postoperative day 1 all patients underwent noncontrast computerized tomography. If there were no residual calcifications, the patient was categorized as not having nephrocalcinosis. If there were residual calcifications, the patient underwent secondary percutaneous nephrolithotomy. If the calcifications were found to be stones, the patient was categorized as not having nephrocalcinosis. If the calcifications were not stones, the patient was categorized as having nephrocalcinosis. Patients were grouped based on the type of stones that formed, including hydroxyapatite, brushite and idiopathic calcium oxalate. The extent of nephrocalcinosis was quantified as 0--absent nephrocalcinosis to 3--extensive nephrocalcinosis. Patients with residual calcifications on postoperative day 1 noncontrast computerized tomography who did not undergo secondary percutaneous nephrolithotomy were excluded from analysis. The presence or absence of nephrocalcinosis was correlated with metabolic studies. RESULTS: A total of 67 patients were studied, including 14 with hydroxyapatite, 19 with brushite and 34 with idiopathic calcium oxalate calculi. Nephrocalcinosis was present in 10 of 14 (71.4%), 11 of 19 (57.9%) and 6 of 34 patients (17.6%) in the hydroxyapatite, brushite and idiopathic calcium oxalate groups, respectively (chi-square p = 0.01). The mean extent of nephrocalcinosis per group was 1.98, 1.32 and 0.18 for hydroxyapatite, brushite and idiopathic calcium oxalate, respectively (p ≤0.001). The presence of nephrocalcinosis positively correlated with urine calcium excretion (mean ± SD 287.39 ± 112.49 vs 223.68 ± 100.67 mg per day, p = 0.03). CONCLUSIONS: Patients without systemic disease who form hydroxyapatite and brushite stones commonly have coexistent nephrocalcinosis. Nephrocalcinosis can occur in calcium oxalate stone formers but the quantity and frequency of nephrocalcinosis in this group are dramatically less.

Vascular complications after percutaneous nephrolithotomy: 10 years of experience.

OBJECTIVE: To provide a contemporary look at vascular complications after percutaneous nephrolithotomy (PNL) with access performed solely by a urologist using fluoroscopic guidance. METHODS: A retrospective review of 2792 patients who had 3338 PNLs at Indiana University Health Methodist Hospital and Mayo Clinic Rochester was performed. Patients who experienced significant bleeding requiring diagnostic renal angiography and superselective embolization (SSE) were reviewed and compared with the overall database. RESULTS: There were 15 patients (16 renal units) requiring renal angiography and SSE (0.48%). Mean time from PNL to bleeding was 7 days (range, 1-15 days) and to SSE was 9.6 days (range, 2-18 days). Mean drop in hemoglobin was 5.3 g/dL (range, 2-9 g/dL). Transfusion was needed in 9 patients (60%). There were no differences between the vascular complications group and the uneventful PNL group in mean age (55.06 vs 52.2 years; P = .519), UTI history (40% vs 38%; P = .92), mean operative time (125.8 vs 102.47 minutes; P = .192), the need for multiple access (18.75% vs 18%; P = .939), and access location. The vascular complications group had a lower stone burden than the uneventful PNL group (stones > 2 cm; 43.7% vs 74.03%; P = .014). CONCLUSION: The incidence of vascular complications in this contemporary series is one of the lowest reported to date. At our centers, vascular bleeding complications appear to be a random and rare event after PNL as we were unable to identify any specific risk factors. Early SSE avoided the need for blood transfusion in many patients.

Introduction of a Renal Papillary Grading System for Patients with Nephrolithiasis.

Introduction: An overlooked finding at the time of renal endoscopy for patients with nephrolithiasis is the appearance of the renal papillae. Recent work has demonstrated that it is possible to distinguish specific stone-forming phenotypes by endoscopic patterns of papillary appearance alone.1-4 These variable expressions are likely to have clinical significance; yet, the ability to pursue such research efforts remains limited by the lack of a standardized system to describe these findings. Herein, we describe a novel grading system designed to standardize and simplify the description of renal papillary appearance in stone formers at the time of endoscopy. Materials and Methods: Since 1999, 342 patients have been prospectively enrolled and given consent to be part of an NIH funded project studying the pathogenesis of stone formation at a single institution (Methodist Hospital, Indiana University Health). Patients have been treated and studied using both percutaneous and retrograde ureteroscopic approaches. Digital scopes are utilized when feasible along with fluoroscopy to map the affected renal unit(s), and stones are removed and analyzed individually when possible.5 Results: Four recurring abnormal papillary features were identified based upon the collective knowledge and expertise of the primary research team. Each variable was then quantitated based on the severity in appearance. Three features believed to be associated with papillary injury include ductal plugging, pitting, and loss of papillary contour. Ductal plugging is evident as either suburothelial deposits of yellow mineral or as dilated ducts of Bellini, presumably left behind after a plug has passed. These two subfeatures are considered the same for the purposes of grading. Pitting reflects crater-like erosion of the papillary surface. Loss of contour reflects global depression of the papilla relative to the surrounding tissue. Upon papillary inspection, each papilla receives a numerical grade from 0 to 2 for each of these measured domains. The three scores are then added together to create a sum total score regarding the degree of papillary injury ranging from 0 to 6. The fourth feature, the amount of Randall's plaque, is evident as white deposits along the papillary surface. It is not known to cause papillary injury6 and, as such, is designated with an alphabetical subscore (a-c) rather than a number. Each papilla then receives a final unique score incorporating both the sum numerical and alphabetical grade. Reference examples are shown in the accompanying video. Conclusions: The creation of a standardized system to describe the papillary appearance in stone formers has considerable clinical and academic utility. On a clinical level, it could be applied as a tool to document intraoperative findings and determine changes in papillary appearance over time in recurrent stone formers. It also has the potential to distinguish high-risk patients with more pressing needs of metabolic evaluations, medical therapy, and surveillance imaging. As a research tool, it would help create a common language to describe papillary appearance and improve collaboration between researchers. It also might allow surgeons to better correlate endoscopic findings to pathological findings and clinical outcomes such as stone analysis, associated metabolic diseases, risk of progressive renal injury, and stone recurrence. No competing financial interests exist. Accompanying manuscript submitted to Journal of Endourology (END-2015-0298; in review). Runtime of video: 5 mins 37 secs.