Journal of Endourology

Urinary diversion and augmentation cystoplasty are associated with long-term complications, including metabolic derangements, infectious complications, and urolithiasis. The aim of this series was to characterize upper and lower urinary tract (LUT) calculi in this population.

A retrospective chart review was performed on all patients with a history of urinary diversion or augmentation cystoplasty who subsequently underwent treatment for urolithiasis between January 1998 and May 2015. Data collected included demographics, perioperative characteristics, type of reconstructive procedure, urine culture, stone analysis, and metabolic evaluation. A statistical analysis was performed.

Ninety-nine patients were identified with a history of urolithiasis and incontinent urinary diversion (28), neobladder (21), continent cutaneous diversion (12), and augmentation cystoplasty (38). LUT stones were more common than upper tract stones in all except for incontinent diversions, which only had one lower tract stone (p = 0.0001). Twenty-three percent of stones were metabolic. Several metabolic derangements were noted, including hypocitraturia (100%), elevated urine pH (100%), low urine volume (70%), and hyperoxaluria (35%). There was a 44% rate of recurrent urolithiasis.

Given the high rate of stone recurrence among patients with a history of urinary diversion and augmentation cystoplasty, all measures should be taken to prevent recurrent stones. In addition to actions aimed to prevent infectious stones such as bladder and pouch irrigation, we recommend these patients undergo a full metabolic workup with targeted dietary changes and medical therapies.

Previous robot-assisted partial nephrectomy (RAPN) studies have identified various predictors of overall and major postoperative complications, but few have evaluated the specific role of these factors in the development of medical and surgical complications. In this study, we present an analysis of the modifiable and nonmodifiable variables influencing medical and surgical complications in a contemporary series of patients who underwent RAPN and were followed in a prospectively maintained, multi-institutional kidney cancer database.

A retrospective review of all patients who underwent RAPN at four institutions between 2008 and 2015 was performed. Multivariable logistic regression models were used to determine predictors of medical and surgical postoperative complications.

Data from 1139 patients were available for analysis. Sixty-seven patients (5.8%) experienced a medical postoperative complication, and 82 (7.1%) experienced a surgical complication. Decreasing baseline estimated glomerular filtration rate (eGFR) (odds ratio [OR] = 0.98, p = 0.003), greater estimated blood loss (EBL) (OR = 1.002, p = 0.001), and operating surgeon (OR = 8.01, p < 0.001) were associated with an increased likelihood of surgical complications, while decreasing baseline eGFR (OR = 0.99, p = 0.054) and operating surgeon (OR = 1.96, p = 0.054) were associated with an increased likelihood of medical complications.

We present complication risks in a large contemporary cohort of patients undergoing robotic partial nephrectomy (RPN) with only 11.3% of patients experiencing a medical or surgical postoperative complication. Prospective candidates for robotic PN with poor baseline renal function and/or risk factors for greater EBL, including a high body mass index, or a complex renal mass should be counseled appropriately on their increased risk for a medical or surgical postoperative complication.

To present the experience of pediatric percutaneous nephrolithotomy (PCNL) of our center.

This study was conducted from 1995 to 2015, on patients <15 years of age having renal and upper ureteral stones who underwent PCNL. Stones were classified as per Guy's stone score (GSS). Standard bull's eye technique was used for subcostal puncture. To avoid supracostal puncture, puncture was done in full inspiration or by oblique tract. If these maneuvers failed, then supracostal puncture was done. Tract was dilated to 24F.

Six hundred sixty PCNLs were performed on 639 patients. Puncture was subcostal in 87.6% cases with tract dilated as much as 24F. Pelvicaliceal system was most commonly accessed through middle calix (73.94%). Upper caliceal puncture (23.78%) was more frequently used in complete (82.35%) and partial staghorn (51%) stones. Two tracts were made in 16 (2.42%) cases, because of large stone burden. Average operative time was significantly longer in complex (45.43 minutes) compared to simple stones (29.39 minutes). Overall success rate was 94.39%, but it was significantly lower in partial (91.37%) and complete staghorn stones (82.35%). Complications were present in 21.66% cases and were classified according to Clavien grading. Majority of patients (97.9%) had minor complications (Clavien grade 1 & 2). On multivariate analysis, GSS ≥2, stone size >200 mm², and multiple caliceal, partial, and complete staghorn stones were predictors of failure and complications.

PCNL is a minimally invasive surgical technique for removal of renal and upper ureteral stones, which have low morbidity rate, high success rate, and short hospital stay. Although the uses of smaller instruments are on the rise, procedure can still be safely performed in children using adult instruments. Supracostal approach if done cautiously does not increase morbidity rate.

The purpose of this study is twofold: first, to describe the non-narcotic pathway (NNP) for the management of postoperative pain after robotic pyeloplasty (RP); second, to compare perioperative outcomes for children undergoing RP whose postoperative pain was managed with and without the NNP.

A retrospective review was performed on 96 consecutive patients from October 2011 to December 2015 who underwent RP by three primary surgeons at a single pediatric institution. Children managed with an NNP received alternating doses of scheduled intravenous acetaminophen and ketorolac every 3 hours throughout the postoperative course. Perioperative outcomes were compared after grouping patients according to the type of postoperative pain management pathway. Continuous variables were compared using the Mann–Whitney U test, and categorical variables were compared using the two-tailed chi-squared test.

A total of 49 (51.0%) patients were managed with the NNP, and 47 (49.0%) patients were managed without the NNP. A larger proportion of patients in the NNP did not receive postoperative narcotic medications (71.4% vs 25.5%; p < 0.001). Patients in the NNP were administered less narcotics (median 0.000 mg vs 0.041 mg morphine equivalents/kg/day; p < 0.001) and had a shorter length of stay (median 1.0 day vs 2.0 days; p < 0.001). There was no significant difference in the proportion of patients with postoperative complications (p = 0.958) or surgical success (p = 0.958).

An NNP following pediatric RP is a viable and effective analgesic regimen that is associated with less narcotic use. It may also facilitate a shorter hospital stay. The majority of patients managed with this pathway had adequate pain control without being subject to the potential adverse effects of narcotic medications.

To investigate whether ureteroscopic biopsy (URS-Bx) for upper tract urothelial carcinoma (UTUC) before radical nephroureterectomy affects intravesical recurrence (IVR).

Of the 515 patients receiving radical nephroureterectomy for UTUC between 1998 and 2012, 387 patients were included for the analysis. URS-Bx was performed in 69 patients (17.8%). Patients were stratified according to tumor location, and the impact of URS-Bx on IVR was evaluated after adjusting for other clinicopathologic variables.

IVR occurred in 163 patients (42.1%). The postoperative 5-year IVR-free survival was not significantly different according to URS-Bx in the overall patient group (54.0% vs 39.3%, p = 0.056). In patients with renal pelvic tumor, IVR-free probability was lower in patients with URS-Bx than in patients without URS-Bx (39.6% vs 62.2%, p = 0.012), although IVR-free survival in patients with ureteral tumor was equivalent (36.7% vs 45.8%, p = 0.946). In multivariate analysis, previous bladder tumors (hazard ratio [HR], 1.65; p = 0.016) were a significant risk factor for IVR in all patients and ureteral tumor location (HR, 1.35; p = 0.071) was associated with IVR, although statistical significance was not achieved. In patients with renal pelvic tumor, URS-Bx HR, 1.98; p = 0.020 was the only risk factor for IVR. However, URS-Bx was not associated with IVR in patients with ureteral tumor, although previous bladder tumor HR, 1.74; p = 0.028 was a risk factor for IVR.

URS-Bx is a significant risk factor for IVR in patients with renal pelvic tumor and should be performed after sufficient consideration in these patients if other examinations are uncertain.

Ureteroscopy is increasingly used to treat upper tract urinary stone disease. A negative ureteroscopy is a ureteroscopy performed with the intent of removing a kidney or ureteral stone, but in which ultimately no stone is removed. Negative ureteroscopy may occur when the stone is found to have already passed, or the presumed stone is found to be outside of the collecting system. We sought to determine the rate of negative ureteroscopy in a large population-based sample as well as factors associated with its use.

We examined nonpublic data from the Office of Statewide Health Planning and Development (OSHPD) Database for all patients in California undergoing outpatient surgery from 2010 to 2012. We identified all patients with an International Classification of Diseases, Ninth Revision (ICD-9) diagnosis code for upper tract urinary stone disease, who underwent a ureteroscopic procedure. After excluding patients undergoing second look procedures or who had diagnosis codes for separate urologic pathology, the negative ureteroscopy rate was defined as the proportion of those ureteroscopy cases coded as a diagnostic ureteroscopy. We fit logistic regression models to evaluate patient factors associated with negative ureteroscopy.

During the years 2010 to 2012, 20,236 eligible patients underwent ureteroscopic procedures for upper tract stone disease. Of these, 1287 patients underwent diagnostic ureteroscopy and 19,039 underwent ureteroscopy with stone removal accounting for a negative ureteroscopy rate of 6.3%. The odds of receipt of a negative ureteroscopy rate were higher in females compared to males (odds ratio [OR] 1.41, 95% confidence interval [CI] 1.25, 1.58) and lower in self-pay patients compared with insured patients (OR = 0.55, 95% CI 0.33, 0.91).

Negative ureteroscopy is common, occurring in nearly 1 in 16 procedures to treat urinary stone disease.

The efficiency of holmium laser lithotripsy for urolithiasis depends upon several factors, including laser pulse energy and frequency and stone composition and retropulsion. This study investigates the complex interplay between these factors and quantifies lithotripsy efficiency using different laser settings in a benchtop kidney and ureter model.

In vitro caliceal and ex vivo porcine ureteral models were constructed. Calcium oxalate monohydrate stones were fragmented using a 200-μm laser fiber. In the caliceal model, stone fragmentation and vaporization rates at settings of 0.6 J/5 Hz, 0.2 J/15 Hz, and 0.2 J/50 Hz were compared. In the ureteral model, fragmentation time, retropulsion rate, fragmentation rate, and fragmented stone weight were compared at settings of 0.6 J/5 Hz and 0.2 J/15 Hz. Retropulsive forces generated at 0.6 J/5 Hz, 0.2 J/15 Hz, and 0.2 J/50 Hz settings were compared. Analysis was performed using Student's t-test and one-way ANOVA.

In the caliceal model, the 0.6 J/5 Hz setting fragmented and vaporized stones at a higher rate than the 0.2 J/15 Hz setting (0.072 vs. 0.049 mg/s; p < 0.001). However, when the 0.2 J energy setting was combined with the 50 Hz frequency, the fragmentation rate (0.069 mg/s) was similar to the fragmentation rate at 0.6 J/5 Hz (0.072 mg/s; p = 0.677). In the ureteral model, the 0.6 J/5 Hz setting produced higher fragmentation rates (0.089 vs. 0.049 mg/s; p < 0.001), but resulted in significantly lower fragmented stone weight overall (16.815 vs. 25.485 mg; p = 0.009) due to higher retropulsion rates (0.732 vs. 0.213 mm/s; p < 0.001). Retropulsive forces decreased significantly when pulse energy decreased from 0.6 to 0.2 J (0.907 vs. 0.223 N; p < 0.001). Frequency did not affect retropulsive force at 15 and 50 Hz settings (0.223 vs. 0.288 N; p = 0.509).

Laser lithotripsy of calcium oxalate monohydrate stones in the ureter should be performed using the low-energy, moderate-frequency dusting setting to minimize retropulsion and maximize efficiency. In the renal calix, the low-energy high-frequency setting performed similarly to the high-energy low-frequency setting.

To prospectively analyze and compare the outcomes of using externalized ureteral catheter (EUC) vs Double-J ureteral stent (DJ) in tubeless minimally invasive percutaneous nephrolithotomy (MPCNL).

A total of 109 patients underwent tubeless MPCNL in our institute and have been enrolled into this study. Fifty-six and 53 patients had EUC and DJ positioning at the conclusion of the procedure, respectively. The two approaches have been compared for operative time, intraoperative blood loss, postoperative visual analogue pain scale (VAS) score, analgesic requirement, stent-related symptoms, hospital stay, degree of vesicoureteral reflux (VUR) on the operative side, and complications according to the modified Clavien system.

There were no statistically significant differences between the two groups regarding the mean operative times, mean VAS scores, analgesic requirements, mean hemoglobin drop, mean hospital stay, and overall complication rate. However, compared with DJ group, EUC group presented fewer postoperative stent-related symptoms and less occurrence of severe VUR (p < 0.05).

Positioning EUC in tubeless MPCNL is a safe alternative to DJ in patients with renal or upper ureteral calculi. EUC provides several benefits: obviated the need of a second endoscopic procedure, reduced stent-related discomfort, and lowered the occurrence of severe VUR.

Laparoscopic access for robot-assisted radical prostatectomy (RARP) is often initiated in the periumbilical location. Palmer's point, located in the left upper quadrant, has been reported as an alternative access site for pelvic laparoscopy to reduce morbidity, but not widely reported among urologists. To better understand surgeons' preferences for access and its associated morbidity during RARP, we surveyed surgeons from two urologic organizations.

An anonymous online questionnaire (SurveyMonkey) consisting of 17 questions that assessed training, experience, and preferences for RARP was emailed in December 2014 and collected until February 2015 to members performing RARP of the Endourology Society (ES) and the Michigan Urological Society Improvement Collaborative (MUSIC). Surgeons were also asked to share their personal experience with a vascular, death or life-threatening event (DOLTE), or bowel injury during RARP.

Questionnaires were answered by 111 surgeons in total (ES, n = 71 and MUSIC, n = 40) with an estimated total response rate of 5.5%. In total, 77% reported prior experience with the Veress needle method before exposure to RARP and 71% of respondents primarily use the Veress needle for RARP, with 73% reporting access primarily at the periumbilical location. A personal experience with a vascular or a bowel injury during Veress needle insertion was reported in 18% and 9% of surgeons, respectively; furthermore, 26% of respondents were personally aware of at least 1 DOLTE among colleagues (5% reported 3 or more). The majority (56%) of respondents were unaware of Palmer's point, while among the minority aware of Palmer's point, only 33% reported ever using this location.

In this survey, surgeons most commonly access the abdomen at the periumbilical location with a Veress needle for RARP with the majority not aware or utilizing Palmer's point. Nearly one in five surgeons reported a personal experience with a vascular injury during access for RARP. Palmer's point, located away from major vasculature, may reduce the morbidity of access for RARP and warrants further awareness and study.

We evaluated whether single-layer renorrhaphy (SLR) without collecting system (CS) closure is sufficient following robot-assisted partial nephrectomy (RAPN).

One hundred fifty consecutive patients underwent RAPN by a single surgeon and were prospectively labeled with regard to CS entry during surgery. Patients with CS entry were subdivided into two groups: those with classical renorrhaphy (CR) (i.e., two-layer repair) and those with SLR (i.e., without CS repair). Perioperative variables and outcomes were compared between CR and SLR groups.

Ninety patients had CS entry during RAPN. Of these 90 patients, 64 had CR, and 26 had SLR, with mean ages of 62 and 59 years (p = 0.22), tumor sizes of 3.4 and 3.3 cm (p = 0.61), Mayo Adhesive Probability scores of 1.8 and 1.8 (p = 0.95), and radius, exophytic/endophytic, nearness to CS, and laterality scores of 8.5 and 8.0 (p = 0.16), respectively. Mean warm ischemia times (WITs) were 19.6 and 17.3 minutes (p = 0.04), hospital stays of 3.0 and 2.8 days (p = 0.62), and drain times of 2.9 and 2.7 days (p = 0.65), for the CR and SLR groups, respectively. Using the Clavien-Dindo classification, there were a total of six grade III or higher complications, with no difference between the CR and SLR subgroups (p = 1.0). Renal function using creatinine or glomerular filtration rate as surrogates showed no difference between groups preoperatively or up until 2 years postoperatively.

Omitting CS repair during RAPN with SLR decreases WIT without altering complications, hospital stay, or drain time. Long-term renal function was not associated with CS repair.

To determine whether or not temporary drainage is necessary immediately following laparoscopic (lap) and robot-assisted (rob) pyeloplasty (PP).

Of 99 patients undergoing lap PP (n = 23) or rob PP (n = 76) for treatment of ureteropelvic junction obstruction (UPJO), 52 had no drainage, 47 were given an “easy-flow” drain (EFD). The volume of leaking urine (in mL) was defined as the volume of drainage fluid (in mL) × creatinine concentration in drainage fluid (in μmol/mL)/median urine creatinine concentration (in μmol/mL). An anastomosis was considered to be leaking if the volume of leaking urine exceeded 5 mL/24 hours. During follow-up the PP success rate was evaluated based on clinical symptoms, intravenous urography and diuretic renography for detection of persisting obstruction.

Median creatinine concentration in drainage fluid was 90 μmol/L (range 44–6270 μmol/L) in a median volume of 84 mL (range 5–1400 mL) drained fluid in 24 hours. The median leaking urine volume was 1.18 mL (range 0.07–291.34 mL), a leaking anastomosis was diagnosed in 5/47 (11%) patients. In patients with EFD and without EFD, complications occurred in 15% and 8% (p = 0.342), respectively, with success rates of 98% and 100% (p = 0.475). Complications (Clavien I-III) occurred in 4/42 (9.5%) patients with watertight and in 3/5 (60%) patients with leaking anastomosis (p = 0.019). No statistically significant differences were noted between lap PP and rob PP patients regarding complication and success rates.

Lap PP and rob PP were primary watertight in 89% of all patients. A primary leaking anastomosis had no influence on PP outcome, but was associated with a higher risk of complications. However, neither the success rate nor the complication rate differed between drained and undrained patients. We conclude, therefore, that drainage is not necessary.

The aim of this study was to evaluate the safety, feasibility, and effectiveness of bipolar transurethral plasmakinetic enucleation of the prostate (PKEP).

Between January 2010 and October 2013, 245 patients with lower urinary tract symptoms due to benign prostatic hyperplasia underwent transurethral enucleation of prostate using bipolar plasma vaporization energy. Patients were evaluated preoperatively by full detailed history, routine preoperative investigation digital rectal examination, serum prostate-specific antigen, abdominal and transrectal ultrasonography, and maximum flow rates (Q_max).

Patients' ages ranged from 50 to 81 (65.5 ± 6) years with transrectal ultrasound-measured prostate volume of 97.1 ± 36.7 mL resulting in an operating time of 76.9 ± 27.9 minutes, and postoperative irrigation and catheterization times were 3.5 ± 3.2 and 12.7 ± 6.1 hours, respectively. No significant complication occurred intra- or postoperatively. Q_max increased from 7.1 ± 3.2 mL/second preoperative to 18.4 ± 4.2 mL/second (p < 0.001). The International Prostate Symptom Score decreased from 25 ± 6 to 7.9 ± 2.4 (p < 0.01).

This study confirmed that PKEP is a safe, easy to learn, and durable technique suitable for any prostate sizes.

To examine the effect of ureteral access sheath (UAS) on the expression of the pro-inflammatory mediators cyclooxygenase-2 (COX-2) and tumor necrosis factor-α (TNF-α) in the ureteral wall.

In 22 pigs an UAS was inserted and removed after 2 minutes on one side and 2 hours on the contralateral side. Postoperatively ureters were excised in vivo, and tissue samples from the distal (2 minutes/2 hours) and proximal ureter (2 minutes/2 hours) were snap-frozen before quantitative polymerase chain reaction analysis of COX-2 and TNF-α. Five unmanipulated ureteral units from other pigs served as the control group.

Compared to controls COX-2 mRNA was significantly upregulated in all UAS treated ureteral groups. Similarly, TNF-α mRNA was upregulated in all groups except the 2-minute proximal ureteral group. Both COX-2 and TNF-α expression were significantly higher in the distal than in the proximal ureter in the UAS treated ureters. After UAS insertion for 2 minutes, expression levels in the distal ureter were increased 6.5- and 8-fold for COX-2 and TNF-α, respectively; and after 2 hours of UAS placement COX-2 and TNF-α mRNA expression levels were increased 9- and 9.5-fold, respectively.

The pro-inflammatory mediators COX-2 and TNF-α were significantly upregulated in the ureteral wall by the influence of UAS. These findings may have implications for postoperative pain, drainage, and complications.

Transurethral enucleation of the prostate for the management of benign prostatic obstruction (BPO) involves two steps: the enucleation and morcellation procedure. The aim of our study was to assess the efficacy of a morcellator device using disposable and reusable blades with different settings of morcellation speed.

A prospective randomized study was initiated for patients with symptomatic BPO undergoing Thulium laser enucleation of the prostate. Mechanical tissue morcellation was performed using the Piranha™ morcellator (R. Wolf, Knittlingen, Germany) with disposable or reusable blades at 850 (n = 24) or 1500 revolutions per minute (rpm) (n = 24). Patient characteristics, intraoperative complications, and the morcellation rate (g/min) were recorded. Data are expressed as median and interquartile range (IQR).

Forty-eight patients were randomized using disposable (n = 24) or reusable blades (n = 24). For reusable blades, the morcellation rate did not increase when changing the morcellation speed from 850 to 1500 rpm (5 vs 4.53 g/min, p = 0.843). The morcellation rate increased significantly when changing the morcellation speed from 850 to 1500 rpm using single-use blades (4.77 vs 10 g/min, p ≤ 0.014). The morcellation rate was not different at 850 rpm between reusable and single-use blades (5 vs 4.77 g/min, p = 0.671). Conversely, the morcellation rate was significantly different at 1500 rpm between reusable and single-use blades (4.53 vs 10 g/min, p ≤ 0.017). The total morcellation rate (at 850 and 1500 rpm) was significantly increased using single-use blades compared to reusable blades (7.67 vs 4.8 g/min, p ≤ 0.026). Interestingly, enucleated weight (g) and the morcellation rate (g/min) correlated inversely using single-use blades at 1500 rpm (r = −0.742, p ≤ 0.004). Only one superficial bladder injury occurred at 1500 rpm, which needed no further interventions.

The Piranha morcellator facilitates efficient tissue removal with single-use and reusable blades. Disposable morcellator blades increase tissue removal significantly at 1500 rpm.

American Urological Association guidelines for surveillance of renal-cell carcinoma after partial nephrectomy recommend imaging within 3–12 months of surgery. Imaging following partial nephrectomy may be difficult to interpret due to the surgical defect, the use of surgical material, and normal postoperative fluid collections. Our primary objective was to evaluate the frequency of indeterminate postoperative imaging results and how those radiographic findings altered patient management.

Retrospective chart review from 2006 to 2013 of patients who had undergone open, laparoscopic, and robotic partial nephrectomy at our institution was completed. There was a minimum of 2 years of follow-up imaging. Radiology reports were reviewed from follow-up imaging and were categorized as “normal” or “abnormal.”

We identified 180 patients with 127 (70.5%) considered to have normal findings on initial follow-up imaging, and 53 (29.5%) with abnormal findings. Median time to initial postoperative imaging for normal findings was 6.8 months compared with 4.4 months for patients with abnormal postoperative scans (p = 0.02). On subsequent imaging, 60% of abnormal studies were downgraded to normal. The median time to receive a second postoperative image from surgery in the normal and abnormal groups was 13.2 and 10.2 months, respectively. The median time interval to the second imaging study was 6.3 months for normal initial scans compared with 5.2 months for initially abnormal scans (p ≤ 0.01).

Early postoperative imaging after partial nephrectomy frequently results in “abnormal” findings and more subsequent radiology exams even though the findings rarely represent cancer recurrences. Based on our results, and pending further validation from other centers, we believe postoperative CT or MRI surveillance after partial nephrectomy can be safely deferred until 1 year after surgery.