Steeve Doizi

Comparison of New Single-Use Digital Flexible Ureteroscope Versus Nondisposable Fiber Optic and Digital Ureteroscope in a Cadaveric Model

Abstract Purpose: To evaluate LithoVue, the new single-use digital flexible ureteroscope, in a human cadaveric model and compare it with a nondisposable fiber optic and digital flexible ureteroscopes. Materials and Methods: LithoVue, a conventional fiber optic, and digital flexible ureteroscopes were each tested in four renal units of recently deceased female cadavers by three surgeons. The following parameters were analyzed: accessibility to the kidney and navigation of the entire collecting system with and without ureteral access sheath (UAS), lower pole access measuring the deflection of the ureteroscope with the working channel empty, and with inside two different baskets and laser fibers. A subjective evaluation of maneuverability and visibility was assessed by each surgeon at the end of every procedure. Results: Kidney access into the Renal unit 1 was not possible without UAS for all ureteroscopes because of noncompliant ureter at the level of sacroiliac joint. The reusable digital ureteroscope was unable to reach one calix of the lower pole and one calix of the upper pole (Renal units 2 and 3) without UAS placement. Lower pole access with baskets and laser fibers was possible for each ureteroscope after UAS placement. No statistically significant differences were detected in angle deflection between ureteroscopes. The digital ureteroscope was preferred for visibility in all procedures: LithoVue for maneuverability in six procedures, fiber optic in five procedures, and the digital ureteroscope in one procedure. Conclusions: LithoVue seems to be comparable with conventional ureteroscopes in terms of visibility and manipulation into the collecting system in fresh human cadavers. Further studies in humans are needed to determine the clinical value of this new instrument.

Clinical utility of transperineal template-guided mapping biopsy of the prostate after negative magnetic resonance imaging−guided transrectal biopsy

PURPOSE We evaluated the prostate cancer detection with transperineal template-guided mapping biopsy in patients with elevated prostate-specific antigen and negative magnetic resonance imaging (MRI)-guided biopsy. MATERIALS AND METHODS Totally 75 patients underwent transperineal template-guided mapping biopsy for prior negative MRI-guided (cognitive registration) biopsy during April 2013 to August 2014. Primary objective was to report clinically significant cancer detection in this cohort of patients. Significant cancer was defined using varying thresholds of MCL or Gleason grade 3+4 or greater or both. Cancers with more than 80% of positive core length anterior to the level of urethra were termed anterior zone cancer. Secondary objective was to evaluate the potential clinical and radiological predictors for significant cancer detection. RESULTS The mean age was 61.6 ± 6.5 years and median prostate-specific antigen was 10.4 ng/dl (7.9-18) with a mean MRI target size of 7.2mm (4-11). Transperineal template-guided mapping biopsy identified cancer in 36% (27/75) patients and 66.6% (18/27) of them were anterior zone cancers. The rates of detection of clinically significant and insignificant cancer according to the several definitions used range from 22.7% to 30.7% and 5.3% to 13.3%, respectively. Multivariate analysis did not identify any predictors for finding clinically significant and anterior cancers in this group of patients. CONCLUSION Transperineal template-guided mapping biopsy appears to be an excellent biopsy protocol for downstream management following negative MRI-guided biopsy. Most of the cancers detected were predominantly anterior tumors.

Assessment of Urinary Inhibitor or Promoter Activity in Uric Acid Nephrolithiasis

PURPOSE We assessed decreased inhibitor activity or increased promoter activity in the urine of idiopathic uric acid stone formers compared to nonstone formers independent of urinary pH. MATERIALS AND METHODS A total of 30 idiopathic uric acid stone formers, and 9 obese and 12 lean nonstone formers collected 24-hour urine while on a metabolic diet. Three urine aliquots per subject were used to assess spontaneous nucleation (de novo crystal formation), crystal growth using a 0.1 mg/ml anhydrous uric acid seed and steady-state uric acid solubility (the maximum amount of uric acid dissolvable in urine) using a 5 mg/ml uric acid seed. All experiments were performed for 6 hours at a constant pH of 5.0. Uric acid concentration was measured in filtered aliquots at 0, 3 and 6 hours. RESULTS At baseline 24-hour urinary pH was significantly lower and uric acid saturation was significantly higher in idiopathic uric acid stone formers. No significant spontaneous nucleation developed and similar uric acid steady-state solubility was reached in the 3 groups. Idiopathic uric acid stone formers and lean nonstone formers showed a similar decrease in uric acid concentration during crystal growth. Obese nonstone formers started with a higher uric acid concentration and consequently demonstrated a greater decrease in the uric acid concentration for crystal growth. CONCLUSIONS This study suggests that there is no significant difference between idiopathic uric acid stone formers and nonstone formers in promoter or inhibitor activity in whole urine against uric acid stone formation when urine pH is maintained constant. The findings suggest that uric acid stone formation is dictated by high urinary saturation with respect to uric acid, which is driven primarily by low urine pH.

Retrograde intrarenal surgery: An expanding role in treatment of urolithiasis

During the past 3 decades, the surgical management of kidney stones has undergone many technological advances and one is the development of the flexible ureteroscopy. The development of this instrument as well as ancillary equipment such as baskets, graspers, and others, and improvements in lithotripsy with Holmium: YAG laser have led to expand its indications with diagnostic and therapeutic management of medical issues of the upper urinary tract such as urolithiasis and urothelial tumors. The objective of this review is to describe its indications and results in the different scenarios for the treatment of urinary stones.

Do patients have to choose between ejaculation and miction? A systematic review about ejaculation preservation technics for benign prostatic obstruction surgical treatment

PurposeEjaculatory dysfunction is the most common side effect related to surgical treatment of benign prostatic obstruction (BPO). Nowadays, modified surgical techniques and non-ablative techniques have emerged with the aim of preserving antegrade ejaculation. Our objective was to conduce a systematic review of the literature regarding efficacy on ejaculatory preservation of modified endoscopic surgical techniques, and mini-invasive non-ablatives techniques for BPO management.MethodsA systematic review of the literature was carried out on the PubMed database using the following MESH terms: “Prostatic Hyperplasia/surgery” and “Ejaculation”, in combination with the following keywords: “ejaculation preservation”, “photoselective vaporization of the prostate”, “photoselective vapo-enucleation of the prostate”, “holmium laser enucleation of the prostate”, “thulium laser”, “prostatic artery embolization”, “urolift”, “rezum”, and “aquablation”.ResultsThe ejaculation preservation rate of modified-TURP ranged from 66 to 91%. The ejaculation preservation rate of modified-prostate photo-vaporization ranged from 87 to 96%. The only high level of evidence studies available compared prostatic urethral lift (PUL) and aquablation versus regular TURP in prospective randomized-controlled trials. The ejaculation preservation rate of either PUL or aquablation compared to regular TURP was 100 and 90 versus 34%, respectively.ConclusionsNon-ablative therapies and modified endoscopic surgical techniques seemed to be reasonable options for patients eager to preserve their ejaculatory functions.

Impact of Potassium Citrate vs Citric Acid on Urinary Stone Risk in Calcium Phosphate Stone Formers

Purpose: To our knowledge no medication has been shown to be effective for preventing recurrent calcium phosphate urinary stones. Potassium citrate may protect against calcium phosphate stones by enhancing urine citrate excretion and lowering urine calcium but it raises urine pH, which increases calcium phosphate saturation and may negate the beneficial effects. Citric acid can potentially raise urine citrate but not pH and, thus, it may be a useful countermeasure against calcium phosphate stones. We assessed whether these 2 agents could significantly alter urine composition and reduce calcium phosphate saturation. Materials and Methods: In a crossover metabolic study 13 recurrent calcium phosphate stone formers without hypercalciuria were evaluated at the end of 3, 1‐week study phases during which they consumed a fixed metabolic diet and received assigned study medications, including citric acid 30 mEq twice daily, potassium citrate 20 mEq twice daily or matching placebo. We collected 24‐hour urine specimens to perform urine chemistry studies and calculate calcium phosphate saturation indexes. Results: Urine parameters did not significantly differ between the citric acid and placebo phases. Potassium citrate significantly increased urine pH, potassium and citrate compared to citric acid and placebo (p <0.01) with a trend toward lower urine calcium (p = 0.062). Brushite saturation was increased by potassium citrate when calculated by the relative supersaturation ratio but not by the saturation index. Conclusions: Citric acid at a dose of 60 mEq per day did not significantly alter urine composition in calcium phosphate stone formers. The long‐term impact of potassium citrate on calcium phosphate stone recurrence needs to be studied further.

MP54-18 QUANTITATIVE AND QUALITATIVE MULTIMODAL OPTICAL ANALYSIS TO DISCRIMINATE UROTHELIAL CARCINOMA GRADES

INTRODUCTION AND OBJECTIVES: In the framework of urologic oncology, mini-invasive procedures have increased the last decades particularly for urothelial carcinoma. One of the essential step in the management of this disease stay the diagnostic, which strongly impacts the treatment choice. The histopathologic evaluation of the grade of the tumor is a keystone of the diagnosis, and its recognition is not possible with a macroscopic evaluation. Nowadays, this specific intraoperative characteristic evaluation remains difficult despite the emergence of new technologies which use exogenous fluorophore. In our study, we assessed the use of an optical multimodal technique based on endogenous fluorescence combining qualitative and quantitative analysis for the diagnostic of urothelial carcinoma grades. METHODS: Urothelial samples from bladder and upper urinary tract were prospectively included (IRB-00003835) and analyzed on a specific optical multimodal setup based on endogenous fluorescence.The analysis included qualitative analyses with two-photons fluorescence imaging (TPF) and quantitative analyses with spectral analyses and fluorescence lifetime imaging (FLIM). Qualitative analyses were compared with pathological examination. Quantitative analyses was performed with a 870nm excitation wavelength, in the spectral analysis we evaluated the spectra, the redox ratio (NADH and FAD) and the fluorescence lifetime for each sample. RESULTS: We identified 3 major urothelial aspects by TPF. All this samples were correlated with pathological examinations, and permitted to differentiate healthy tissue from low and high grade urothelial carcinoma. In the quantitative analysis, the spectral results shown that the intensity level of the emitted spectra was correlated with the histopathological characteristics: the higher the grade was, the lower was the fluorescence signal. The redox ratio analysis was significantly higher in the healthy urothelium compared with tumors samples (p<0.001). Moreover, we were able to discriminate low grade from high grade tumors, the low grade had a significantly higher redox ratio (p1⁄40.002). We were able to identify the cells structure in the FLIM images and to compare the different grade. This analysis also permitted to discriminate the different origins. The average lifetime in low grade tumor appeared shorter on our images and in the histogram shown significant differences between healthy, low grade and high grade urothelial carcinoma: healthy vs. low grade (p 1⁄4 0.002), healthy vs. high grade (p < 0.001) and high grade vs. low grade (p < 0.001). CONCLUSIONS: Those results show that multimodal optical analysis was able to discriminate low grade from high grade urothelial carcinoma without using exogenous fluorophore. This is a promising technology for the development of an optical fiber setup designed for an intraoperative diagnosis of urothelial carcinoma in the area of endourology.

Dusting technique for lithotripsy: what does it mean?

Kidney stones are currently managed using laser lithotripsy and the most recent generation of laser generators have enabled the possibility of the dusting technique. Dusting avoids the use of a basket, as stone fragments are spontaneously evacuated; however, no consensus on the definition of dust currently exists.

Systematic review of ureteral access sheaths: facts and myths

The aim of the present paper was to review the literature on all available ureteral access sheaths (UASs) with their indications, limitations, risks, advantages and disadvantages in current modern endourological practice. Two authors searched Medline, Scopus, Embase and Web of Science databases to identify studies on UASs published in English. No time period restriction was applied. All original articles reporting outcomes or innovations were included. Additional articles identified through references lists were also included. Case reports, editorials, letters, review articles and meeting abstracts were excluded. A total of 754 abstracts were screened, 176 original articles were assessed for eligibility and 83 articles were included in the review. Based on a low level of evidence, UASs increase irrigation flow during flexible ureteroscopy and decrease intrapelvic pressure and probably infectious complications. Data were controversial and sparse on the impact of UASs on multiple reinsertions and withdrawals of a ureteroscope, stone‐free rates, ureteroscope protection or damage, postoperative pain, risk of ureteral strictures, and also on its cost‐effectiveness. Studies on the benefit of UASs in paediatrics and in patients with a coagulopathy were inconclusive. In the absence of good randomized data, the true impact of UASs on surgery outcome remains unclear. The present review may contribute to the evidence‐based decision‐making process at the individual patient level regarding whether or not a UAS should be used.

MP50-05 IMPACT OF LASER FIBER TIP CLEAVAGE ON POWER OUTPUT FOR URETEROSCOPY AND STONE TREATMENT

patients into two groups: late oncological/post-surgical stricture (group A), or early post-surgical obstruction, leakage or detachment (group B). If appropriate, we performed a retrograde studyþ/rigid ureteroscopy to assess the stricture after 3 month from the procedure, followed by a MAG3 renogram at 6 and 12 months. RESULTS: 35 patients underwent a Rendezvous procedure, 25 in group A (Mean age 59.35, range: 49-74), 10 in group B (Mean age 52.44, range: 36-63). Strictures were successfully stented in 21 out of 25 patient (84%) in the group A, 7 out of 10 in group B (70%). After successful stenting, at 12 month 12/21 of group A required no further interventions and were stent free (56%), 7 (32%) were maintained with long term stenting. Only 2 (11%) required major reconstruction, 2 patients (11%) died during follow up from malignancy. In group B, 4/8 (50%) were stent free with no further interventions, 3/8 (38%) were maintained on long term stenting, only 1 required reconstruction. CONCLUSIONS: With a combined antegrade and retrograde approach, the majority of complex ureteric stricture can be bridged and stented, avoiding major surgery in unfavourable circumstances and allows time for stabilisation and recovery of the patient. Interestingly, if successful, further interventions later may be unnecessary in up to 50-57% of patients. This is particularly useful in elderly patients with a malignant stricture, but also perhaps in young patients with benign discontinuities and a good blood supply to the ureter.