Ureteral Wall Thickness Is an Effective Predictor of Ureteral Stone Impaction and Management Outcomes: A Systematic Review and Meta-analysis.

PURPOSE: Ureteral stone impaction is associated with unfavorable endourological outcomes; however, reliable predictors of stone impaction are limited. We aimed to assess the performance of ureteral wall thickness on noncontrast computed tomography as a predictor of ureteral stone impaction and failure rates of spontaneous stone passage, shock wave lithotripsy, and retrograde guidewire and stent passage. MATERIALS AND METHODS: This study was completed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. A search was conducted in April 2022 for all adult, human, and English language studies investigating ureteral wall thickness using PROSPERO, OVID Medline, OVID EMBASE, Wiley Cochrane Library, Proquest Dissertations & Theses Global, and SCOPUS. A systematic review and meta-analysis using random effects model was conducted. Risk of bias was assessed using the MINORS (Methodological Index for Non-randomized Studies) score. RESULTS: Fourteen studies with a pooled population of 2,987 patients were included for quantitative analysis, and 34 studies were included in our qualitative review. Meta-analysis findings suggest that a thinner ureteral wall thickness is associated with more favorable subgroup stone outcomes. Thinner ureteral wall thickness suggests a lack of stone impaction and was associated with improved rates of spontaneous stone passage, successful retrograde guidewire and stent placement, and improved shock wave lithotripsy outcomes. Studies lack a standardized ureteral wall thickness measurement protocol. CONCLUSIONS: Ureteral wall thickness is a noninvasive measure that predicts ureteral stone impaction, and thin measurements are predictive of successful outcomes. Variability in measurement methods confirms that a standardized ureteral wall thickness protocol is needed, and the clinical utility of ureteral wall thickness is yet to be determined.

Percutaneous management of caliceal diverticula: a narrative review.

PURPOSE OF REVIEW: Caliceal diverticula are relatively uncommon within urologic practice and may be difficult to diagnose and treat. We aim to highlight contemporary studies examining surgical interventions for patients with caliceal diverticula, with a focus on percutaneous intervention, and provide updated practical recommendations for the management of these patients. RECENT FINDINGS: Studies within the last 3 years examining surgical treatment options for caliceal diverticular calculi are limited. When flexible ureteroscopy (f-URS) and percutaneous nephrolithotomy (PCNL) are examined within the same observational cohorts, PCNL is associated with improved stone-free rates (SFRs), lower requirement for re-intervention, and longer lengths of stay (LOS). Retrograde f-URS for the treatment of caliceal diverticula and diverticular calculi is associated with satisfactory safety and efficacy outcomes. There are no studies in the last 3 years that provide supporting evidence to use shock wave lithotripsy to treat caliceal diverticular calculi. SUMMARY: Recent studies examining surgical interventions for patients with caliceal diverticula are limited to small observational studies. Heterogeneity in LOS and follow-up protocol limits comparisons between series. Despite technological advancements in f-URS, PCNL appears to be associated with more favorable and definitive outcomes. PCNL continues to be the preferred treatment strategy for patients with symptomatic caliceal diverticula when deemed technically feasible.

Contemporary Use of Computed Tomography (CT) Imaging in Suspected Urolithiasis in Pregnancy.

PURPOSE OF REVIEW: We aimed to examine the role of low-dose CT (LDCT) in the diagnostic work-up for suspected urolithiasis in pregnancy. We reviewed contemporary urologic recommendations for CT in pregnancy, its utilization for suspected urolithiasis, and explored barriers to its use. RECENT FINDINGS: National urologic guidelines and the American College of Obstetricians and Gynecologists recommend the judicious use of LDCT imaging in pregnancy when necessary. We noted inconsistencies in review article management pathways and recommendations for CT imaging for suspected urolithiasis in pregnancy. Overall CT utilization in pregnancy for suspected urolithiasis is low. Proposed barriers to LDCT use in pregnancy include fears of litigation and misperceptions of the harm of diagnostic radiation. Recent advancements in imaging technologies for urolithiasis in pregnancy are limited. More specific diagnostic pathway recommendations from national urologic guideline bodies for when to use LDCT to investigate renal colic in pregnancy may reduce diagnostic and intervention delays.

Laser fiber degradation following holmium laser enucleation of the prostate utilizing Moses technology versus regular mode.

PURPOSE: We sought to objectively compare laser fiber degradation for holmium laser enucleation of the prostate (HoLEP) cases performed with 550 µm standard fibers versus 550 µm Moses 2.0 fiber in BPH mode on a macroscopic and microscopic level. METHODS: We prospectively collected outcomes for 50 standardized HoLEP cases using 550 µm Moses fiber with 2.0 BPH mode compared to our historical cohort of 50 patients using 550 µm standard fibers on regular mode. Macroscopic degradation length was the difference in length of exposed fiber at the start and end of each case. Five consecutive 550 µm standard fibers, five 550 µm Moses fibers and their respective controls underwent novel utilization of three objective corroborating imaging techniques: Brightfield high resolution microscopy, high resolution 3-D microCT and Confocal Reflection Surface Analysis. Mann-Whitney U, 2-tailed T tests and Chi-squared tests were used. RESULTS: Standard fibers demonstrated greater degradation than the Moses fibers with 2.0 BPH mode [2.9 cm (IQR 1.7-4.3 cm) vs 0.2 cm (IQR 0.1-0.4 cm), p < 0.01]. This difference remained significant when comparing degradation per energy used, per minute enucleation and per gram enucleated (all p < 0.05). None of the cases with Moses fiber and 2.0 BPH mode required intraoperative interruption to re-strip the fiber. Objective fiber degradation by three microscopic techniques confirmed more damage to the standard fibers with regular mode. CONCLUSION: Overall, use of the 550 µm Moses fiber with 2.0 BPH mode resulted in less fiber degradation compared to a standard 550 µm fiber with regular mode as confirmed using 4 corroborating macroscopic and microscopic techniques.

Determining the threshold of acute renal parenchymal damage for intrarenal pressure during flexible ureteroscopy using an in vivo pig model.

PURPOSE: To identify a threshold for intrarenal pressure (IRP), that if exceeded, will result in renal parenchymal damage. Herein, we attempt to identify an IRP threshold by subjecting in vivo porcine kidneys to various levels of extreme pressurized irrigation. Our objective was not to simulate ureteroscopy treatment, but to attempt identify a threshold of IRP injury. METHODS: Ten female pigs were intubated and sedated. The abdomen was opened; the ureters were isolated and incised. A LithoVue™ (Boston Scientific) ureteroscope was inserted. A 0-silk tie was then used to tie the ureter around the scope to create a closed system (to achieve a constant level of pressure). Real-time IRPs were measured using the Comet™ Pressure guidewire (Boston Scientific). Kidneys were exposed to pressurized, saline for 36 min (at control, 50, 100, 150 mmHg and higher pressures). Kidneys were then immediately harvested. Two expert histologists independently analyzed kidney slides to identify areas of renal damage. RESULTS: The two kidneys exposed to IRPs > 185 mmHg resulted in forniceal rupture and large areas of hematoma. The other IRP groups (control, 50, 100, and 150 mmHg) had no identifiable gross or histologic renal parenchymal damage. CONCLUSIONS: No differences in renal parenchymal morphology were identified between pressure groups of control, 50, 100, or 150 mmHg. However, IRPs > 185 mmHg did result in forniceal rupture in this closed-system in vivo porcine model. Further study is required to elucidate the damage threshold.

A Randomized Trial Evaluating the Use of a Smart Water Bottle to Increase Fluid Intake in Stone Formers.

OBJECTIVE: The aim of this study is to evaluate if the use of a smart water bottle improves urine volume in stone forming patients. METHODS: Adults with nephrolithiasis and low urine volume (<1.5 L) documented on a 24-hour urinalysis (24 hr U) were randomized to receive either standard dietary recommendations to increase fluid intake (DR arm), or DR and a smart water bottle (HidrateSpark®; Hydrate Inc., Minneapolis, MN) that recorded fluid intake, synced to the user's smartphone, and provided reminders to drink (SB arm). Participants completed baseline surveys assessing barriers to hydration. They then repeated a 24 hr U and survey at 6 and 12 weeks, respectively. RESULTS: Eighty-five subjects (44 DR, 41 SB) were enrolled. The main baseline factor limiting fluid intake was not remembering to drink (60%). Follow-up 24 hr Us were available for 51 patients. The mean increase in volume was greater in the SB arm (1.37 L, 95% confidence interval -0.51 to 3.25) than the DR arm (0.79 L, 95% confidence interval -1.15 to 2.73) (P = .04). A smaller percentage of subjects in the SB arm reported not remembering to drink as the main factor limiting fluid intake in the follow-up questionnaire compared to baseline (45.4% vs. 68.4%, P < .05). This was not true for the DR arm (40.0% vs. 51.2%, P = .13). CONCLUSIONS: Difficulty remembering to drink is a barrier to achieving sufficient fluid intake in stone formers. The use of a smart bottle was associated with greater increases in 24 hr U volumes and less difficulty remembering to drink.

Prospective randomized trial of 2 versus 12-weeks of postoperative antibiotics after percutaneous nephrolithotomy in complex patients with infection-related kidney stones.

PURPOSE: Treatment of struvite kidney stones requires complete surgical stone removal combined with antibiotic therapy to eliminate urinary tract infections and preventive measures to reduce stone recurrence. The optimal duration of antibiotic therapy is unknown. We sought to determine if 2- or 12-weeks of antibiotics post percutaneous nephrolithotomy (PNL) for infection stones resulted in better outcomes for stone recurrence and positive urine cultures. MATERIAL AND METHODS: This multi-center, prospective randomized trial evaluated patients with the clinical diagnosis of infection stones. Patients were randomized to 2- or 12-weeks of postoperative oral antibiotics (nitrofurantoin or culture-specific antibiotic) and included if residual fragments were ≤4 mm on computed tomography imaging after PNL. Imaging and urine analyses were performed at 3-, 6-, and 12-months post-procedure. RESULTS: Thirty-eight patients were enrolled and randomized to either 2-weeks (n = 20) or 12-weeks (n = 18) of antibiotic therapy post-PNL. Eleven patients were excluded due to residual fragments >4 mm, and 3 patients were lost to follow-up. The primary outcome was the stone-free rate (SFR) at 6 months post-PNL. At 3-, 6-, and 12-months follow-up, SFRs were 72.7% versus 80.0%, 70.0% versus 57.1%, 80.0% versus 57.1% (p = ns), between 2- and 12-week-groups, respectively. At 3-, 6-, and 12-months follow-up, positive urine cultures were 50.0% versus 37.5%, 50.0% versus 83.3%, and 37.5% versus 100% between 2- and 12-week groups, respectively (p = ns). CONCLUSIONS: For patients with stone removal following PNL, neither 2-weeks nor 12-weeks of postoperative oral antibiotics is superior to prevent stones and recurrent positive urine cultures.

A Randomized Controlled Trial of Preoperative Prophylactic Antibiotics for Percutaneous Nephrolithotomy in Moderate to High Infectious Risk Population: A Report from the EDGE Consortium.

PURPOSE: Postoperative infectious related complications are not uncommon after percutaneous nephrolithotomy. Previously, we noted that 7 days of antibiotics did not decrease sepsis rates compared to just perioperative antibiotics in a low risk percutaneous nephrolithotomy population. This study aimed to compare the same regimens in individuals at moderate to high risk for sepsis undergoing percutaneous nephrolithotomy. MATERIALS AND METHODS: Patients were prospectively randomized in this multi-institutional study to either 2 days or 7 days of preoperative antibiotics. Enrolled patients had stones requiring percutaneous nephrolithotomy and had either a positive preoperative urine culture or existing indwelling urinary drainage tube. Primary outcome was difference in sepsis rates between the groups. Secondary outcomes included rate of nonseptic bacteriuria, stone-free rate and length of stay. RESULTS: A total of 123 patients at 7 institutions were analyzed. There was no difference in sepsis rates between groups on univariate analysis. Similarly, there were no differences in nonseptic bacteriuria, stone-free rate and length of stay. On multivariate analysis, 2 days of antibiotics increased the risk of sepsis compared to 7 days of antibiotics (OR 3.1, 95% CI 1.1-8.9, p=0.031). Patients receiving antibiotics for 2 days had higher rates of staghorn calculus than the 7-day group (58% vs 32%, p=0.006) but post hoc subanalysis did not demonstrate increased sepsis in the staghorn only group. CONCLUSIONS: Giving 7 days of preoperative antibiotics vs 2 days decreases the risk of sepsis in moderate to high risk percutaneous nephrolithotomy patients. Future guidelines should consider infectious risk stratification for percutaneous nephrolithotomy antibiotic recommendations.

Treatment of non-obstructive, non-struvite urolithiasis is effective in treatment of recurrent urinary tract infections.

PURPOSE: To determine if treatment of non-obstructing urolithiasis is effective in management of recurrent UTI. MATERIALS AND METHODS: A retrospective review was performed of patients undergoing elective management of non-struvite upper tract urinary calculi with recurrent UTI from 2009 to 2016. Recurrent UTI was defined at ≥ 3 UTI in 12 months, with symptoms and documented urine culture. Preoperative CT was performed in all patients to determine stone burden. All patients had postoperative imaging and ≥ 12 months of follow-up. Pre- and postoperative variables were between patients who had recurrent UTI after treatment versus those who did not. RESULTS: 46 patients met inclusion criteria. 42 (91.3%) were female. Median age was 63.7 years (IQR 49.1, 73.4) and median total stone burden was 20 mm (IQR 14-35). Within the cohort, 20 (43.5%) underwent ureteroscopy only, 26 (56.5%) underwent PCNL ± URS, and none underwent ESWL. Median postoperative follow-up was 2.9 years (IQR 2.0, 4.3). Only five patients (10.9%) had recurrent UTI after treatment. 80% were with the preoperative pathogen. The presence of residual stone was an independent risk factor for recurrent UTI after treatment (p < 0.046). Diabetes, hypertension, immunosuppression and chronic kidney disease were not. CONCLUSIONS: Stone removal for patients with recurrent UTIs was associated with a high rate of success (89.1%) in elimination of further recurrent UTIs. Residual fragments are independently associated with persistent recurrent UTIs and thus, complete stone removal is of paramount importance in treatment of this patient population.

The use of outpatient opioid medication for acute renal colic and ureteral stents: Insights from a multi-institutional patient survey
.

AIMS: To investigate the main reasons for use of opioids during acute episodes of renal colic and for ureteral stent symptoms post-operatively. MATERIAL AND METHODS: A survey assessing the impact of decreased quality of life and use of opioid pain medication was distributed to patients with a history of ureteral stent at seven academic centers between July 2016 and June 2018. RESULTS: A total of 365 surveys were completed. Opioid use for stone (63.9%) and stent-related pain (39.0%) was common among respondents. When assessing whether patients used more opioids for stone or stent-related pain, 47.7% reported using more for stone pain while 15.0% reported using more for stent pain. 22.6% of patients required opioids for stent-related pain and not stone pain. Increasing patient age was found to be negatively associated with using opioids for stent-related pain (OR: 0.4, 95% CI: 0.3 - 0.6). Increasing age was also found to be negatively associated with opioid use for stone pain (OR: 0.6, 95% CI: 0.4 - 0.8). Patients with a greater number of prior stones had 3.2 times the odds of using opioids for stone pain, in our adjusted model (95% CI: 2.1 - 4.7). CONCLUSION: Patients with more prior stone episodes are more likely to have used opioids for their most recent episode. Although ureteral stents have been shown to be associated with a decreased quality of life, we showed that the use of opioids for stent-related pain is less than that for stone pain. Younger patients are less likely to tolerate a stent without opioid analgesics.

Conversion from Cystine to Noncystine Stones: Incidence and Associated Factors.

PURPOSE: Patients with cystinuria are often treated with medical alkalization and shock wave lithotripsy, although each treatment is hypothesized to increase the risk of calcium phosphate stones. We performed a multicenter retrospective review to evaluate whether stones of another composition develop in patients with cystinuria and with what frequency. MATERIALS AND METHODS: We retrospectively reviewed the records of a multi-institutional cohort of patients with cystinuria. We assessed medications, stone analyses, 24-hour urinalyses and types of procedures. We compared patients who formed only cystine stones vs those with noncystine stones. RESULTS: We identified 125 patients from a total of 5 institutions who were followed a mean of 5.2 years (range 0 to 26). Stones with noncystine components were submitted by 37 patients (29.6%). Potassium citrate medication was not associated with a noncystine composition (p = 0.1877). Regarding surgical management 18 patients (13%) underwent at least 1 shock wave lithotripsy session (range 0 to 9) and 79 (63%) underwent percutaneous nephrolithotomy at least once (range 0 to 10). When stratified based on pure cystine vs converted stones, the average total number of shock wave lithotripsy and percutaneous nephrolithotomy procedures was higher in the group with cystine and subsequent noncystine stone compositions (0.94 vs 0.10, p <0.0001, and 1.7 vs 1.5, p = 0.0053, respectively). On logistic regression male gender (OR 3.1, p = 0.0280) and the number of shock wave lithotripsy sessions (OR 3.0, p = 0.0170) were associated with an increased likelihood of the development of stones with a noncystine composition. CONCLUSIONS: Stones with noncystine components develop in more than 25% of patients with cystinuria, underscoring the importance of continued stone analysis. In this study prior shock wave lithotripsy was associated with conversion to a noncystine stone composition while urinary alkalization therapy was not associated.

A Randomized Controlled Trial of Preoperative Prophylactic Antibiotics Prior to Percutaneous Nephrolithotomy in a Low Infectious Risk Population: A Report from the EDGE Consortium.

PURPOSE: Single institution studies suggest a benefit of a week of preoperative antibiotics prior to percutaneous nephrolithotomy. These studies are limited by lower quality methodology, such as the inclusion of heterogeneous populations or nonstandard definitions of sepsis. The AUA (American Urological Association) Best Practice Statement recommends less than 24 hours of intravenous antibiotics but to our knowledge no other data exist on the duration or benefit of preoperative antibiotics. Using CONSORT (Consolidated Reporting of Trials) guidelines we sought to perform a rigorous multi-institutional trial to assess preoperative antibiotics in patients in whom percutaneous nephrolithotomy was planned and who were at low risk for infection. MATERIALS AND METHODS: This randomized controlled trial enrolled patients undergoing percutaneous nephrolithotomy who were at low risk, defined as negative preoperative urine cultures and no urinary drain. Of the subjects 43 were randomized to nitrofurantoin 100 mg twice daily for 7 days preoperatively while a control arm of 43 received no oral antibiotics. All subjects received perioperative doses of ampicillin and gentamicin. Prone percutaneous nephrolithotomy was performed by urologists blinded to randomization. The primary outcome was the development of sepsis. RESULTS: A total of 86 subjects were enrolled. Preoperative patient characteristics were similar in the treatment and control cohorts with a stone size of 19 and 17 mm, respectively (p = 0.47). Intraoperative characteristics also did not differ. The sepsis rate was not statistically different between the treatment and control groups (12% and 14%, respectively, 95% CI -0.163-0.122, p = 1.0). Other infectious parameters and complications were similar, including intensive care admission, fever, hypotension and leukocytosis. CONCLUSIONS: Our study demonstrated no advantage to providing 1 week of preoperative oral antibiotics in patients at low risk for infectious complications who undergo percutaneous nephrolithotomy. Perioperative antibiotics according to the AUA Best Practice Statement appear sufficient.

Dusting versus Basketing during Ureteroscopy-Which Technique is More Efficacious? A Prospective Multicenter Trial from the EDGE Research Consortium.

PURPOSE: There is scant evidence in the literature to support dusting vs active basket extraction during ureteroscopy for kidney stones. We prospectively evaluated and followed patients to determine which modality produced a higher stone-free rate with the fewest complications. MATERIALS AND METHODS: Members of the Endourologic Disease Group for Excellence research consortium prospectively enrolled patients with a renal stone burden ranging from 5 to 20 mm in this study. A holmium laser was used and all patients were stented postoperatively. Ureteral access sheaths were used in 100% of basketing cases while sheaths were optional when dusting. The primary study outcome was the stone-free rate at 6 weeks as determined by x-ray and ultrasound. RESULTS: A total of 84 and 75 patients were enrolled in the basketing and dusting arms, respectively. Stones in the dusting group were significantly larger (mean ± SD stone area 96.1 ± 65.3 vs 63.3 ± 46.0 mm2, p <0.001). The stone-free rate was significantly higher in the basketing group on univariate analysis (74.3% vs 58.2%, p = 0.04) but not on multivariate analysis (1.9 OR, 95% CI 0.9-4.3, p = 0.11). In patients who underwent a basketing procedure operative time was 37.7 minutes longer than in those treated with a dusting procedure (95% CI 23.8-51.7, p <0.001). There was no statistically significant difference in complication rates, hospital readmissions or additional procedures between the groups. CONCLUSIONS: The stone-free rate was higher for active basket retrieval of fragments at short-term followup on univariate analysis but not on multivariate analysis. There was no difference in postoperative complications or procedures. The 2 techniques should be in the armamentarium of the urologist.

Holmium laser enucleation of the prostate is an effective treatment in patients with concomitant bladder diverticula and outlet obstruction.

INTRODUCTION: Bladder diverticula can be congenital or secondary to benign prostatic hyperplasia with bladder outlet obstruction, and be a source of high postvoid residuals prompting surgical intervention. We sought to evaluate the outcomes of patients with bladder diverticula undergoing holmium laser enucleation of the prostate (HoLEP) for bladder outlet obstruction. METHODS: We retrospectively reviewed HoLEP patients with at least one bladder diverticulum at two high volume institutions. All cases were performed in similar fashion. Preoperative, perioperative, and postoperative patient variables were obtained and assessed. RESULTS: Of 2746 HoLEP patients, 51 were diagnosed with bladder diverticula before surgery. Mean prostate size was 80.8 ± 50.0 g and mean diverticulum size (largest if multiple) was 5.5 ± 2.6 cm. Preoperatively, urinary retention requiring catheterization was present in 28 (55%) patients. In the remainder, mean preoperative AUASI was 19.7, peak flow 7.2 ml/s, and post-void residual (PVR) 365 ml. At most recent follow-up (mean 12.2 months), mean total AUASI was 8.6, peak flow 27.1 ml/s, and PVR 145 ml with 71, 276, and 221% improvement, respectively. All patients were voiding and none required catheterization. Only three (6%) patients required diverticulectomy at a mean of 15.2 months after HoLEP for the following indications: hematuria (one patient) and urinary retention (two patients). CONCLUSIONS: HoLEP is an effective method of outlet obstruction treatment in patients with bladder diverticula. Most patients, even with large diverticula, do not require further treatment after the outlet obstruction has been relieved and can avoid more invasive surgical interventions.

Evidence-based outcomes of holmium laser enucleation of the prostate.

PURPOSE OF REVIEW: Holmium laser enucleation of the prostate (HoLEP) has been a mainstay therapy for the treatment of lower urinary tract symptoms (LUTS) secondary to benign prostate hyperplasia (BPH) for nearly 20 years. We briefly review current and sentinel publications that provide outcomes data after HoLEP. RECENT FINDINGS: Current literature continues to support HoLEP as a versatile and durable surgical option for men with LUTS secondary to BPH. Despite evidence supporting durable symptom relief beyond 10 years even in large prostate glands, HoLEP is still not widely available to all patients. Concerns surrounding the learning curve of the procedure, high rates of retrograde ejaculation, and transient urinary incontinence seem to persist and limit the adoption of HoLEP by established urologists and residency training programs. SUMMARY: Recent publications continue to show excellent short-term and long-term outcomes after HoLEP, in the categories of voiding function and patient satisfaction. Continued attempts to demonstrate equivalent outcomes of alternate-BPH surgical techniques are being met with renewed efforts by those performing HoLEP to demonstrate equivalent outcomes and patient safety during the learning phase of HoLEP for both mentored and self-directed surgical training.

Outcomes of Holmium Laser Enucleation of the Prostate in the Re-Treatment Setting.

PURPOSE: Holmium laser enucleation of the prostate can also be applied in the re-treatment setting when other benign prostatic hyperplasia therapies fail. We compared outcomes in men who underwent holmium laser enucleation of the prostate in the primary vs the re-treatment setting. MATERIALS AND METHODS: We retrospectively reviewed the records of 2,242 patients who underwent holmium laser enucleation of the prostate at a total of 4 academic hospitals between 2003 and 2015. Patient demographics, and operative and perioperative outcomes were compared between re-treatment and primary holmium laser enucleation of the prostate. RESULTS: Of the 360 of 2,242 men (16%) who underwent re-treatment holmium laser enucleation of the prostate the procedure was done for residual urinary symptoms in 71%. The most common primary procedure was transurethral resection of the prostate in 42% of cases. Mean time between prior benign prostatic hyperplasia surgery and re-treatment was 68 months (range 1 to 444). There were no significant differences in age, prostate size, AUA (American Urological Association) symptom score or average flow rate between the cohorts. Perioperatively, re-treatment holmium laser enucleation of the prostate was associated with significantly shorter operative time, reduced blood loss, lower specimen weight and shorter length of stay. The AUA symptom score improved in both groups, although it remained higher in men who underwent re-treatment (6.5 vs 5.0, p <0.001). The likelihood of clot retention (4.7% vs 1.8%, p = 0.01) and urethral stricture (3.3% vs 1.5%, p = 0.043) was slightly higher in the re-treatment group. CONCLUSIONS: Immediate perioperative outcomes of holmium laser enucleation of the prostate performed in the re-treatment setting were no different from those in the primary setting. While re-treatment was associated with an increased likelihood of clot retention, urethral stricture and higher AUA symptom score, these minimal differences must be considered against the overall favorable symptom improvement across both cohorts.

Surgical intervention for urolithiasis: does it result in long-term medical complications?

The association of shock wave lithotripsy (SWL) and hypertension is a controversial subject. This Commentary discusses the article by Denberg et al., which found an association between new-onset hypertension and SWL, but not ureteroscopy. Ureteroscopy has improved significantly since its introduction and now plays a role as a primary initial treatment for stone disease.

Natural History, Complications and Re-Intervention Rates of Asymptomatic Residual Stone Fragments after Ureteroscopy: a Report from the EDGE Research Consortium.

PURPOSE: Fragments 4 mm or smaller after ureteroscopy historically have been considered clinically insignificant but there is a reported 20% event rate on followup even with stones 4 mm or smaller. In this study we examine the natural history, complications and re-intervention rates of fragments after ureteroscopy. MATERIALS AND METHODS: Data from 6 centers were collected retrospectively from members of the Endourology Disease Group for Excellence in 232 patients who had residual fragments after ureteroscopy between 2006 and 2013. Patients with fragment(s) of any size on imaging within 12 months were eligible. The primary outcome measured was stone events, and secondary outcomes included stone growth, stone passage, re-intervention and complications. RESULTS: Of the 232 subjects with fragments 131 (56%) required no further intervention and remained asymptomatic, 34 (15%) experienced complications requiring no intervention and 67 (29%) required intervention, ie the primary outcome stone event rate was 44%. Fragments larger than 4 mm were more likely to grow with time (p <0.001) and were associated with more complications (p=0.039). Fragments larger than 2 mm were more likely to grow (p <0.001) but were not associated with complications or re-intervention. Re-intervention was predictable based on fragment size (p=0.017). In a multivariable logistic regression model there was no significant difference between the techniques of dusting stones or basket extraction. CONCLUSIONS: This study suggests that fragment size larger than 4 mm after ureteroscopy is associated with significantly higher rates of stone growth, complications and the need for re-intervention. Ensuring complete stone-free status is the most effective strategy to reduce stone events after ureteroscopy.

Buckshot colic: utilizing holmium:yag laser for ureteroscopic removal of a bullet fragment within the proximal ureter.

Buckshot colic is a rare phenomenon, presenting as firearm-induced urinary tract obstruction. We present a case of gunshot-induced ureteral obstruction in a 49-year-old male, treated endoscopically with the holmium:YAG (holmium) laser. CT revealed a 1 cm bullet fragment within the left proximal ureter. A percutaneous nephrolithotomy was performed utilizing the holmium laser to fragment the metal into basket-retrievable pieces. At 4 month follow up the patient is without evidence of stricture. To our knowledge, this is the first reported utilization of the holmium laser to treat "buckshot colic". Endoscopy with holmium laser appears a feasible and safe treatment option.

Metabolic acidosis with hemodilution due to massive absorption of normal saline as bladder irrigation fluid following holmium laser enucleation of prostate.

Holmium laser enucleation of prostate (HoLEP) is being performed with increasing frequency as a minimally invasive alternative to transurethral resection of the prostate (TURP) for the surgical management of benign prostatic hyperplasia (BPH). HoLEP offers the advantage of use of normal saline for irrigation, instead of glycine which is utilized in TURP, decreasing the likelihood of fluid absorption and effects on serum electrolytes. We describe a patient who underwent HoLEP for BPH and subsequently developed non-ion gap metabolic acidosis and hemodilution associated with volume overload.