The Economic Implications of a Reusable Flexible Digital Ureteroscope: A Cost-Benefit Analysis.

PURPOSE: Questions remain regarding the durability and longevity of flexible ureteroscopes. The objective of this study was to estimate the potential economic benefits of single use, flexible digital ureteroscopes compared to our recent experience with reusable flexible digital ureteroscopes using cost-benefit analysis. MATERIALS AND METHODS: Ureteroscopic procedures were prospectively recorded over the 12-month period of February 2014 to February 2015. All flexible ureteroscopies were performed using Flex XC digital ureteroscopes (Karl Storz Endoscopy-America, El Segundo, California). Cost assessment was based on the original purchasing cost and repair-exchange fees divided by the number of cases. An algorithm was created to include per case reprocessing costs and calculate the benefit-to-cost ratio. This cost was compared to potential costs of the LithoVue™, a single use digital ureteroscope. RESULTS: In 160 cases a flexible reusable ureteroscope was used. There was damage to 11 ureteroscopes during this time with an average of 12.5 cases to failure. Excluding original purchasing costs, the cost analysis revealed an amortized cost of $848.10 per use. After 99 ureteroscope cases the cost-benefit analysis favored reusable ureteroscopes compared to disposable ureteroscopes. CONCLUSIONS: Digital ureteroscopes are the latest trend in the evolution of endourology. It appears that a disposable ureteroscope may be cost beneficial at centers with a lower case volume per year. However, institutions with a high volume of cases may find reusable ureteroscopes cost beneficial.

Infectious complications associated with the use of temporary prostatic urethral stents in patients with benign prostatic hyperplasia.

INTRODUCTION: To examine the infectious outcomes after the insertion of the temporary prostatic urethral stent (TPUS) in benign prostatic hyperplasia (BPH) patients. MATERIAL AND METHODS: Between November 2007 and September 2012, ninety TPUS were used in 33 patients with BPH at our institution. All patients had negative urine cultures prior to the first stent insertion. TPUS were sent for cultures at time of removal or exchange. Stents were removed at the time of definite surgical intervention, at 4-6 weeks, or when patients elected another course of treatment. Colonization was defined as asymptomatic positive stent culture. Infection was defined as symptomatic positive stent culture requiring treatment. Infection and colonization rates are reported. Logistic regression was used to examine the predictors of infection at any point. Predictors examined were age, body mass index, history of prostate cancer, diabetes mellitus, hyperlipidemia, coronary artery disease, neurologic disorder, erectile dysfunction and the sequence of stent placement. RESULTS: The majority of the subjects, 72% (24/33) had 1-2 stents, 9.0% (3/33) had 3-4 stents, 6.0% (2/33) had 5-6 stents, and 12% (4/33) of patients had more than 6 stents. From the 69 available culture results, the symptomatic infection rate was 16% (11/69) (95% CI: 8.2%-26.7%). The colonization rate was 58% (40/69) (95% CI: 45.5%-69.7%). None of the predictors examined were identified as a predictor of infection. There was no colonization detected when stents were removed in the first 20 days. CONCLUSION: Infection rates with TPUS in BPH patients are acceptable and early removal may prevent colonization.

Procedures needed to maintain functionality of adult continent catheterizable channels: a comparison of continent cutaneous ileal cecocystoplasty with tunneled catheterizable channels.

PURPOSE: We compared the outcomes of various adult continent catheterizable channels in a multi-institutional setting. MATERIALS AND METHODS: We retrospectively reviewed the records of all adults who underwent construction of a continent catheterizable channel at our 4 institutions from 2004 to 2013 and who had at least 6 months of followup. Patients were stratified by channel type, including continent cutaneous ileal cecocystoplasty or tunneled cutaneous channel, eg appendicovesicostomy, Monti channel, etc. The primary study outcome was the need for a secondary procedure to correct stomal leakage, catheterizable channel obstruction or stomal stenosis. Secondary outcomes were patient reported leakage and 30-day postoperative complications. We used Firth logistic regression to control for the heterogeneity induced by multiple institutions. RESULTS: A total of 61 patients were included in study, of whom 31 underwent continent cutaneous ileal cecocystoplasty. Mean age was 41.4 years (range 22 to 76). Median followup was 16 months. More patients with a tunneled channel required a secondary procedure than those with cecocystoplasty (15 of 30 or 50% vs 4 of 31 or 13%, OR 6.4, 95% CI 1.8-28). The total number of required secondary procedures was also greater for tunneled channels than for cecocystoplasty (27 vs 4). Of patients with cecocystoplasty 29% reported stomal leakage compared with 43% of those with a tunneled channel (p = 0.12). A high rate of postoperative complications was observed regardless of technique, including 40% for channels and 51.7% for cecocystoplasty. CONCLUSIONS: Patients with continent cutaneous ileal cecocystoplasty undergo fewer interventions to maintain the catheterizable channel than patients with a tunneled continent catheterizable channel.

Preoperative stone attenuation value predicts success after shock wave lithotripsy in children.

PURPOSE: We determined whether stone attenuation can predict stone fragmentation after shock wave lithotripsy in the pediatric population. Previous studies show that preoperative attenuation in HU on noncontrast computerized tomography predicts shock wave lithotripsy success. To our knowledge study of this parameter in the pediatric population has been lacking to date. MATERIALS AND METHODS: We performed a multi-institutional review of the records of 53 pediatric patients 1 to 18 years old who underwent shock wave lithotripsy for 3.8 to 36.0 mm renal calculi. Stone size, average skin-to-stone distance and attenuation value were determined by bone windows on preoperative noncontrast computerized tomography. Success was defined as radiographically stone-free status at 2 to 12-week followup after a single lithotripsy session without the need for further sessions or ancillary procedures. RESULTS: After lithotripsy 33 patients (62%) were stone-free and 20 had incomplete fragmentation or required additional procedures. Mean ± SD stone attenuation in successfully treated patients vs those with incomplete fragmentation was 710 ± 294 vs 994 ± 379 HU (p = 0.007). Logistical regression analysis revealed that only attenuation in HU was a significant predictor of success. When patients were stratified into 2 groups (less than 1,000 and 1,000 HU or greater), the shock wave lithotripsy success rate was 77% and 33%, respectively (p <0.003). CONCLUSIONS: Stone attenuation less than 1,000 HU is a significant predictor of shock wave lithotripsy success in the pediatric population. This finding suggests that attenuation values have a similar predictive value in the pediatric population as that previously reported in the adult population.

Stone size is only independent predictor of shock wave lithotripsy success in children: a community experience.

PURPOSE: We determined whether age, gender, body mass index, number of stones, stone location or total stone diameter could independently predict stone-free rates after extracorporeal shock wave lithotripsy in children. MATERIALS AND METHODS: We reviewed 149 patients 3 to 17 years old undergoing shock wave lithotripsy between 2001 and 2008. Cases were retrieved from a regional shock wave lithotripsy database. Variables analyzed included age, gender, body mass index, number of shocks delivered, stone location, number of stones and total stone diameter. Stone-free status on followup imaging at 2 weeks to 3 months was considered a successful outcome. RESULTS: Of 149 patients 32 had multiple stones. After shock wave lithotripsy 106 patients (71%) were stone-free, 12 (8%) required a repeat procedure and 31 (21%) had residual fragments. Number of stones per patient ranged from 1 to 18 (mean +/- SD 2.14 +/- 2.60). Mean +/- SD number of stones was 1.87 +/- 2.42 in successfully treated patients and 2.81 +/- 2.92 in those with treatment failure (p = 0.065). Total stone diameter ranged from 2 to 90 mm (mean +/- SD 14.03 +/- 16.68). Mean total stone diameter was 11.1 +/- 13.4 mm in successfully treated patients and 21.3 +/- 21.4 mm in those with treatment failure (p <0.005). CONCLUSIONS: To our knowledge we present the first multi-institutional cohort study in children demonstrating no significant relationship between successful outcome and patient age, gender, body mass index, stone location or number of stones. Only total stone diameter independently predicted shock wave lithotripsy success.

Long-term follow up of patients undergoing reoperative surgery with aortic or mitral valve replacement using a St. Jude Medical prosthesis.

BACKGROUND AND AIM OF THE STUDY: Between June 1978 and September 2002, a total of 440 reoperative open-heart patients (mean age 62 +/- 14 years; range: 18-91 years), following various primary cardiac operations, underwent single-valve replacement with the St. Jude Medical (SJM) heart valve. Of 241 patients having aortic replacement (AVR) and 199 mitral valve replacement (MVR), 86 (35%) and 42 (21%), respectively, underwent concomitant coronary artery bypass grafting. The study aim was to document patient survival and valve-related events in an experience extending up to 24 years after reoperative open-heart surgery with a single model cardiac valve prosthesis. METHODS: The Cardiac Surgical Associates Research Foundation (CSARF) has maintained an independent database of those patients with the SJM prosthesis since the world's first implant in October 1977. Patients were contacted by questionnaire and/or telephone between November 2002 and June 2003. The hospital course and valve-related events were verified by patient chart review and/or physician contact. RESULTS: Follow up was 94% complete, for a total of 3,114 patient-years (1,671 pt-yr after AVR; 1,443 pt-yr after MVR). The average follow up was 7 +/- 6 years (range: 0.1-24.3 years). The operative mortality was 9% (10% AVR, 8% MVR). Five deaths (13%) were valve-related. Freedom from all late mortality at 10 and 20 years, respectively, was 57% and 35% for AVR and 52% and 22% for MVR, and for valve-related mortality was 89% and 77% for AVR and 84% and 22% for MVR. Freedom from thromboembolic events at 10 and 20 years, respectively, was 93% and 93% after AVR and 92% and 81% after MVR; from anticoagulant-related hemorrhage it was 78% and 76% after AVR and 81% and 67% after MVR; and from reoperation it was 94% and 94% after AVR and 95% and 89% after MVR. CONCLUSION: Reoperative valve replacement carries a significant operative morbidity and mortality. Long-term results with the SJM valve demonstrated a durable prosthetic valve, excellent long-term patient survival, and freedom from valve-related events followed reoperative open-heart valve replacement surgery. However, the early postoperative period carried an increased risk for valve-related events.

Robot Assisted Renal Allograft Nephrectomy: Initial Case Series and Description of Technique.

OBJECTIVE: To evaluate the outcomes and perioperative complication rates following robot- assisted transplant nephrectomy ((RATN). METHODS: All patients who underwent RATN at our institution were included. No exclusion criteria were applied. Clinical records were retrospectively reviewed and reported. This included preoperative, intraoperative, and postoperative outcomes. Complications were reported utilizing the Clavien-Dindo classification system. Descriptive statistics were reported using frequencies and percentages for categorical variables, means and standard deviation for continuous variables. RESULTS: Between July 2014 and April 2018, 15 patients underwent RATN. Most patients had the transplant in the right iliac fossa (13/15). Ten patients underwent a concomitant procedure. The total operative time for the entire cohort was 336 (±102) minutes (including cases who had concomitant procedures) and 259 (±46 minutes) when cases with concomitant procedures were excluded. Mean estimated blood loss was 383 (±444) mL. Postoperatively, 3 patients required blood transfusion. Average hospital stay was 4 (±2.7) days. Most patients had finding consistent with graft rejection on final pathology. There were 5 complications; 3 of which were minor (grade 2 = 2 and grade 3 = 1); one patient had a wound infection requiring dressing (3A) and one patient died due to pulmonary embolism following discharge. Limitations include small series and retrospective nature of the study. CONCLUSION: This case series demonstrate that RATN is technically feasible. With continued experience and larger case series, the robotic approach may provide a minimally invasive alternative to open allograft nephrectomy.

Predictive Factors for Achieving the Recommended AUA Daily Urine Production in Patients With Nephrolithiasis.

OBJECTIVE: To identify factors that predict kidney stone patient's ability to produce 2.5 L urine volume per day on metabolic evaluation. PATIENTS AND METHODS: In a retrospective chart review, the first analysis evaluated initial 24-hour urine collections with respect to those who achieved or did not achieve a urine volume of 2.5 L/day. The second analysis evaluated those who achieved or did not achieve a daily urine volume of 2.5 L on their subsequent collection. Several variables were assessed. RESULTS: Patients' initial collections (n=1100) that achieved 2.5 L/day (n=274) were of younger age and had a higher body mass index, increased urine sodium, phosphorus, calcium levels, increased protein catabolic rate, and decreased supersaturation of calcium oxalate. In the second analysis (n=273), decreased supersaturation of calcium oxalate, increased urine urea nitrogen level, and increased protein catabolic rate were observed in subsequent collections with a urine volume of 2.5 L/day or more. Patients with a diagnosis of hyponatremia were less likely to achieve 2.5 L/day urine volume. Collection date, other comorbidities, and diuretic use were not associated with achieving 2.5 L/day urine volume. Patients' mean creatinine per kilogram for all study cohorts were within the range of adequate collection. CONCLUSION: Predictive factors for a urine volume of 2.5 L/day or more include increased fluid intake, higher salt and animal protein diet, elevated body mass index, and male sex. Patients with these factors may require interventions other than hydration recommendations to optimize their prevention of future kidney.

Morcellation Efficiency in Holmium Laser Enucleation of the Prostate: Oscillating Morcellator Outperforms Reciprocating Morcellator With no Apparent Learning Curve.

OBJECTIVE: To compare the morcellation efficiency of the Wolf Piranha oscillating morcellator with the Lumenis VersaCut reciprocating morcellator. MATERIALS AND METHODS: After institutional review board approval, we conducted a retrospective analysis of patients undergoing holmium laser enucleation of the prostate (HoLEP) for symptomatic benign prostatic hyperplasia. The first 41 cases of HoLEP with morcellation performed with the oscillating morcellator were matched by weight of resected tissue to 41 control patients from our historic data set who underwent morcellation with the reciprocating system. The primary outcome of interest was morcellation efficiency. We also evaluated surgeon experience level to assess for a learning curve with the oscillating morcellator. RESULTS: The 41 patients from each group were comparable in terms of age, prostate size, continuation of aspirin, and catheter status. The oscillating morcellation efficiency was nearly double that of the reciprocating morcellator (8.6 g/min [range: 3.0-18.3] vs 3.8 g/min [range: 0.9-10.1], P <.0001). Mean resected weights for cases with the oscillating and reciprocating instruments were 69 g (range: 17-224 g) and 69 g (range: 17-213 g), respectively (P = .9). The total operative time and complication rates did not significantly differ. For the oscillating system, morcellation efficiency for cases performed by staff alone was 9.8 g/min compared with 8.1 g/min when trainees were involved (P = .2), and there was no correlation between morcellation efficiency and number of cases performed (R = 0.01). CONCLUSION: The oscillating morcellation system resulted in a morcellation efficiency double that of the reciprocating system for tissue retrieval after HoLEP. Achieving efficiency with the oscillating system was not associated with a significant learning curve and was not impacted by trainee involvement.

Holmium Laser Enucleation of the Prostate After Prostatic Urethral Lift Surgery: Feasibility and Technical Considerations from a Multi-Institutional Case Series.

INTRODUCTION AND OBJECTIVE: Ten percent of patients undergoing prostatic urethral lift (PUL) require repeat surgical treatment within 3 years. We describe the feasibility and considerations of performing holmium laser enucleation of the prostate (HoLEP) as a salvage therapy after previous PUL. METHODS: Men who had undergone HoLEP after PUL were retrospectively identified from three institutions with surgeons experienced in HoLEP. Subjects were characterized by age, time from PUL procedure (months) to HoLEP surgery, indication for retreatment, and pre-operative prostate volume by ultrasound. Outcomes of interest included enucleation time, morcellation time, morcellator type, weight of tissue resected, and Clavien complications. We also summarize findings related to the location of PUL device implants, and the effect of the implants on the enucleation and morcellation portions of the procedure. RESULTS: From December 15, 2015 to October 31, 2016, seven men aged 51-78 years underwent HoLEP at a median of 8.6 months (range 3-18) after PUL. The median prostate volume by transrectal ultrasound was 80 cm3 (range 56-160 cm3). For the 7 patients, 6 out of the 22 device implants were found in aberrant locations. Auxiliary maneuvers were required in five cases. Morcellation devices tended to jam with each implant, requiring a pause for withdrawal of the morcellator and manual removal from the blade or requiring grasper retrieval of device components. There were no Clavien complications. CONCLUSIONS: HoLEP can be performed safely and effectively post-PUL; however, device implants may be found in areas other than the intended location, and morcellation of the adenoma tissue is complicated by metallic implants of the PUL device.

A New Laser Platform for Holmium Laser Enucleation of the Prostate: Does the Lumenis Pulse 120H Laser Platform Improve Enucleation Efficiency?

OBJECTIVE: To determine whether the recently introduced Lumenis Pulse 120H laser platform, which offers a dual-pedal footswitch and preset energy modes to easily switch among laser settings, facilitates a more efficient process in holmium laser enucleation of the prostate (HoLEP) for surgical treatment of benign prostatic hyperplasia. PATIENTS AND METHODS: Patients at a single institution who underwent HoLEP with the new Lumenis Pulse 120H laser platform were matched 1:2 with patients who underwent the procedure with the previously used 100-watt VersaPulse single-pedal laser platform. Matching was performed by using propensity scores calculated by a logistic model that considered preoperative transrectal ultrasound prostate volume and patient age. The primary outcome was enucleation efficiency of each platform, determined by the weight of prostate tissue resected and enucleation time. The McNemar test and a conditional logistic model were used to associate predictors and cases. RESULTS: Twenty-nine patients who underwent HoLEP with the Lumenis Pulse 120H platform were matched with 58 patients who underwent the procedure with the 100-watt platform. We observed statistically significant differences in operating room total time, procedure time, and enucleation time. Other perioperative and postoperative outcomes were comparable between the 2 groups. Enucleation efficiency was similar between the 2 laser platforms (0.89 g per minute in the control group vs 0.84 g per minute in the Lumenis Pulse 120H group). CONCLUSION: The efficiency of the new Lumenis Pulse 120H laser platform is comparable to the 100-watt VersaPulse laser platform in HoLEP when comparing g of tissue enucleated per minute.

Robot-assisted Transplanted Ureteral Stricture Management.

OBJECTIVE: To assess the feasibility of robot-assisted transplanted ureteral reimplantation as a minimally invasive alternative to open surgery. MATERIAL AND METHODS: Between August 2015 and March 2016, 5 patients presented with transplanted ureteral strictures after failure of a previous endoscopic management. All patients underwent robot-assisted ureteral reimplantation. Patients' demographics, perioperative outcomes, and complications are reported. RESULTS: All patients presented with deterioration of kidney function with or without recurrent urinary tract infection. Two patients had short strictures (<1 cm) and 2 had long strictures (>1 cm), whereas 1 patient had a nitinol ureteral stent in situ. The location of the stricture varied among these patients with 3 distal and 1 proximal. Intraoperatively, 3 patients had a modified Lich-Gregoir reimplantation and 2 patients had a pyelovesicostomy. The mean operative time was 164 (±52) minutes. There were no intraoperative complications, conversion to open surgery, or significant blood loss necessitating blood transfusion. There were no urine leaks in the immediate or late postoperative period. One patient developed a Clavien grade IVa complication (sepsis). The median length of stay, the duration of catheterization, and the duration of stenting were 1 day (range 1-5 days), 7 days (range 6-14 days), and 39 days (range 25-51 days), respectively. After a median follow-up of 79 days (range 40-139 days), no strictures or delayed leakages were identified. CONCLUSION: Robot-assisted transplanted ureteral reimplantation is technically feasible. With a larger number of cases and a longer follow-up, robot-assisted transplanted ureteral reimplantation may provide a new and effective, minimally invasive alternative for the treatment of this complex surgical problem.

Operating Endoscopically with "Two Hands" to Remove Calcified Permanent Suture After Pyeloplasty.

We describe a combined percutaneous and endoscopic approach to remove encrusted permanent suture in the renal pelvis that was placed during pyeloplasty repair. Our index patient had a laparoscopic dismembered pyeloplasty at an outside institution 10 years before presenting with flank pain and nondependent nephrolithiasis. This proved to be an encrusted permanent suture material. There is limited data on incidence of nephrolithiasis after ureteropelvic junction repair, but it is well documented that nonabsorbable suture lines should be avoided in the urinary tract as they may serve as a nidus for stone formation.

Characterizing and Simulating Needle Insertion Forces for Percutaneous Renal Access.

BACKGROUND: Percutaneous needle access is a critical step of performing percutaneous nephrolithotomy. Development of a synthetic model that accurately represents the forces encountered while gaining percutaneous renal access, allows for high ease of use and prevention of negative skill transfer. The objectives of this study were to define the needle insertion forces used during percutaneous renal access and to develop a multilayer synthetic physical simulator model based on human tissue data that is compatible with the SimPORTAL fluoro-less C-arm trainer (CAT) camera system. MATERIALS AND METHODS: Needle insertion data were collected using in situ fresh human cadaveric tissue within 72 hours of death. Ultrasound guidance was used to place percutaneous reference needles into the kidney, and axial force vs displacement data was collected using a custom-built force measurement device. A novel multilayer model that includes several types of synthetic materials for simulation of distinct tissue layers was developed based on the human tissue reference data. The multilayer prototype model and an existing single material model were subsequently tested using the same needle insertion protocol and the results were compared with human tissue data. RESULTS: Average maximum forces for needle puncture into skin ranged from 2.75 to 2.80 N for human tissue and from 4.53 to 4.19 N for simulated human tissue. The overall slope for all force vs displacement data was 0.35 to 0.59 N/cm for human tissue. The overall slope was comparatively lower for the multilayer model (0.17 N/cm) and was highest in the existing single material model (5.08-9.79 N/cm). CONCLUSIONS: We have defined the forces for percutaneous renal access using fresh human cadaveric tissue and designed a multilayer synthetic simulator model that can be utilized for training percutaneous needle access to the renal collecting system using the CAT camera system.

Urologic problems in spina bifida patients transitioning to adult care.

OBJECTIVE: To identify the urologic needs of adult patients with spina bifida (SB) at the time of their transition from pediatric to adult care. We hypothesized that delays in transition to adult care would be associated with higher rates of active problems. METHODS: We retrospectively reviewed patients seen at adult dedicated SB clinics at the Universities of Utah and Minnesota from April 2011 to April 2012. We reviewed bladder management, urologic problems, time from last urologic care, and necessary interventions. RESULTS: We identified 65 patients from these clinics with SB. The mean age was 30.6 years (standard deviation, 11.3). The median time since last urologic evaluation at Utah and Minnesota was 17 months and 12 months, respectively (range 1 month-10 years). Fifty-five patients (85%) reported a urologic problem at the time of their visit. Urinary incontinence was most common in 34 (52%), followed by recurrent urinary tract infection in 22 (34%), catheterization troubles in 8 (12%), and calculi in 6 (9%). Sixty-three patients (97%) required some sort of intervention. These were diagnostic (cystoscopy, ultrasonography, computed tomography scan, urodynamics) in 50 patients (77%), surgical (urinary diversion, onabotulinum toxin A injection, stone surgery, and so forth) in 22 (34%), and medical (antimicrobial prophylaxis, bladder irrigations, anticholinergics, self-catheterization) in 16 (25%). There was no association between longer transition times and higher rates of active problems. CONCLUSION: On presentation to adult SB clinics, patients had many active urologic problems and operative management was often needed; however, there was no association between longer transition times and higher rates of active problems.

Pediatric extracorporeal shock wave lithotripsy: Predicting successful outcomes.

Extracorporeal shock wave lithotripsy (ESWL) is currently a first-line procedure of most upper urinary tract stones <2 cm of size because of established success rates, its minimal invasiveness and long-term safety with minimal complications. Given that alternative surgical and endourological options exist for the management of stone disease and that ESWL failure often results in the need for repeat ESWL or secondary procedures, it is highly desirable to identify variables predicting successful outcomes of ESWL in the pediatric population. Despite numerous reports and growing experience, few prospective studies and guidelines for pediatric ESWL have been completed. Variation in the methods by which study parameters are measured and reported can make it difficult to compare individual studies or make definitive recommendations. There is ongoing work and a need for continuing improvement of imaging protocols in children with renal colic, with a current focus on minimizing exposure to ionizing radiation, perhaps utilizing advancements in ultrasound and magnetic resonance imaging. This report provides a review of the current literature evaluating the patient attributes and stone factors that may be predictive of successful ESWL outcomes along with reviewing the role of pre-operative imaging and considerations for patient safety.