Sean McAdams

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.

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

Stone Size is Only Independent Predictor of Shock Wave Lithotripsy Success in Children: A Community Experience

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.

Pediatric extracorporeal shock wave lithotripsy: Predicting successful outcomes

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.

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

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.

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

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.

V5-01 HOLMIUM LASER ENUCLEATION OF THE PROSTATE AS RETREATMENT AFTER UROLIFT DEVICE: FEASIBILITY AND TECHNICAL CONSIDERATIONS

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.

V3-02 TRANSPERITONEAL ROBOT ASSISTED INFERIOR VENA CAVA FILTER EXTRACTION: YOU ALREADY KNOW HOW TO DO THIS!

INTRODUCTION AND OBJECTIVES: In this video we demonstrate the feasibility of Holmium laser enucleation of the prostate (HoLEP) for retreatment of persistent lower urinary tract symptoms (LUTS) after previous treatment with the UroLift device. Technical considerations with regards to both enucleation and morcellation of resected tissue are discussed. Benign prostatic hyperplasia (BPH) affects millions of men worldwide. The UroLift system (NeoTract Inc., Pleasanton, CA) was recently introduced as a means to perform prostatic urethral lift (PUL) procedure for lateral lobe hypertrophy in patients with obstructive voiding symptoms. Urolift has been associated with a retreatment rate of 7% at 2 years and 14% at 4 years. Retreatment with TURP, photovaporization of the prostate and repeat UroLift has been described without notable issue, but retreatment with HoLEP has not yet been described. METHODS: We included two patients who had undergone PUL with UroLift system at outside institutions and presented with recurrent LUTS. Patients were evaluated by cystoscopy, uroflowmetry, transrectal ultrasound of the prostate, and urodynamics to define the etiology of their urinary symptoms and determine appropriate therapy. HoLEP was performed under general anesthesia as previously described. Morcellation of the resected adenoma was performed with the VersaCut reciprocating morcellator (Lumenis Inc, Santa Clara, CA). RESULTS: Enucleation was successfully completed in both patients. Monofilament sutures of the Urolift device were easily visualized and transected with the holmium laser. At the bladder neck, both patients were unexpectedly found to have the outer nitinol tab portions of UroLift devices located within the capsule of the prostate, rather than in the intended extracapsular location. Auxiliary maneuvers were required for removal of these nitinol tabs. The inner stainless steel portions of the UroLift device were encountered during morcellation of the resected adenoma. In each instance, the metal tabs became lodged in the reciprocating blades of the morcellator, requiring withdrawal of the morcellator instrument and manual removal of the tab from the morcellator blade. This resulted in brief disruptions in the procedure. There were no operative complications. CONCLUSIONS: To our knowledge, we present the first description of HoLEP with morcellation of adenoma tissue after previous prostatic urethral lift surgery with the UroLift device. HoLEP can be performed safely and effectively post Urolift, however morcellation of the adenoma tissue is complicated by the metallic implants of the Urolift device.

MP06-03 ROBOT ASSISTED TRANSPLANT ALLOGRAFT NEPHRECTOMY SERIES: A NOVEL APPROACH FOR A CHALLENGING OPERATION

INTRODUCTION AND OBJECTIVES: Horseshoe kidney is a congenital anomaly in which the fused kidneys fail to ascend to their normal position. Anatomic aberrations including renal malrotation and the presence of an isthmus can make access to the posterior renal anatomy challenging. Persistent embryonic arteries combined with variations in origin, number, and size of renal arteries contribute to the increased potential of excess blood loss during surgery. Taken together, these anatomic variations make minimally invasive surgery in horseshoe kidneys technically challenging. Although minimally invasive techniques have been utilized for partial nephrectomy (PN) in horseshoe kidneys, reporting on technical modifications during robot-assisted techniques is minimal. Here, we present a case of a renal mass located in a horseshoe kidney and describe our technique for robot-assisted PN in this patient population. METHODS: A 65-year-old female presented with an incidental finding of a 5.6 cm posteriorly occurring enhancing renal mass on the left lower pole of her previously undiagnosed horseshoe kidney. Workup included a CT angiogram for further evaluation of renal vasculature. Nephrometry score was 2+1+3+P+21⁄4 8-P-H. The left moiety was fed by two renal arteries with significant distance between them, and a single renal vein inserting more distally into the inferior vena cava. The patient ultimately opted for robot-assisted PN. A fourth arm Grasping Retractor was utilized early for improved hilar retraction, and later for folding the kidney on its isthmus to create posterior access and optimal exposure during tumor enucleation. Intravenous indocyanine green (ICG) instillation was used in conjunction with near infrared fluorescence to attempt selective arterial clamping and improve intraoperative understanding of renal perfusion as well as the renal mass. RESULTS: Console time was 157 minutes with an estimated blood loss of 300 mL. Warm ischemia time was 19 minutes. The patient was discharged on post-operative day one. There were no perioperative complications. Pathology revealed a 5.7 cm oncocytoma. CONCLUSIONS: We demonstrate that using ICG and the 4th arm are technical considerations that can assist with robot-assisted PN in a horseshoe kidney, especially for posteriorly occurring tumors.

Operating Endoscopically with “Two Hands” to Remove Calcified Permanent Suture After Pyeloplasty

INTRODUCTION AND OBJECTIVES: Despite improvements in medical care, surgical removal of failed transplant renal allografts may be mandated by sepsis, bleeding, pain, or erythropoietin resistance. Transplant nephrectomy has historically been performed in an open fashion by transplant surgeons and carries morbidity up to 50% with mortality up to 7%. To date, there is a single reported case of robot assisted transplant allograft nephrectomy from a deceased donor kidney. We herein present our series of robotic assisted transplant nephrectomy (RTN). METHODS: All patients who underwent robotic allograft nephrectomy at Mayo Clinic Arizona were included. Patients were not excluded for undergoing a concurrent procedure. All RTN were performed by a single Urologist (EPC) in conjunction with a single Transplant surgeon (NNK) via a transperitoneal approach utilizing a dual console Da Vinci Robotic Si/Xi surgical system. Study design was retrospective and observational. Variables analyzed included: demographics (age, BMI, ASA), comorbidities, transplant related (time from transplant to transplant nephrectomy, living related or deceased donor transplants), operative variables (operative time, estimated blood loss and additional procedures performed) peri-operative variables (length of stay (LOS), drain duration, Foley catheter duration, and hemoglobin change), and 30-day Clavien-Dindo complications. All variables were analyzed by non-parametric tests with commercially available software (SPSS vs, 21, Chicago, Illinois RESULTS: Six patients underwent RTN between 10/31/2014 until 4/31/2016. The time from transplant to transplant nephrectomy was a median of 5.9 years (range: 0.3 40). The majority of transplants were from deceased donors (66%). The median operating time was 306 minutes (range: 178 e 532). Of note, in two of the six RTN cases bilateral laparoscopic native nephrectomies were performed and in a third case a robotic nephrectomy and a lymph node biopsy by plastic surgery was performed. There were no intraoperative complications or conversions to open nephrectomy. Estimated median blood loss was 150 mL (range: 100 e 400), with a transfusion rate of 16%. Drains were utilized in 84% of patients and for a median of 2 days. There were three minor complications. CONCLUSIONS: In this first reported series of robotic transabdominal allograft nephrectomy we demonstrate the safety and feasibility of the use of robotic technology for transplant nephrectomy. This is a small series that includes our learning curve.