Which Patients with Upper Tract Urothelial Carcinoma Can be Safely Treated with Flexible Ureteroscopy with Holmium:YAG Laser Photoablation? Long-Term Results from a High Volume Institution.

PURPOSE: We tested the effects of tumor size, distribution and grade on progression-free survival in patients with upper tract urothelial carcinoma treated with flexible ureteroscopy with Ho:YAG laser photoablation. MATERIALS AND METHODS: Included in analysis were data on 92 consecutive patients with upper tract urothelial carcinoma treated with Ho:YAG laser photoablation from 2003 to 2015 at a single tertiary care referral center. Stringent followup was offered according to EAU (European Association of Urology) guidelines. Progression during followup was defined by tumor upgrading, distant metastases and/or a relapsing tumor that could not be completely removed with a conservative approach. Kaplan-Meier curves were used to assess the rate of disease progression according to tumor size (1 or less cm vs greater than 1 cm), tumor distribution (unifocal vs multifocal) and tumor grade (low vs high). Cox regression analysis was done to test the impact of clinical and pathological characteristics on the rate of progression-free survival. RESULTS: At a median followup of 52 months (IQR 27.8-76.4) the progression-free survival rate was 68% vs 72% in patients with a tumor size of 1 or less vs greater than 1 cm (p = 0.9), 72% vs 69% in patients with unifocal vs multifocal lesions (p = 0.6) and 75% vs 52% in patients with a low vs a high grade tumor (p = 0.03). On multivariable Cox regression analysis tumor grade at first treatment was the only independent predictor of disease progression (HR 5.16, 95% CI 1.19-22.26, p = 0.03). CONCLUSIONS: High tumor grade independently decreased progression-free survival in patients with upper tract urothelial carcinoma treated with Ho:YAG laser photoablation. Tumor size greater than 1 cm and multifocality did not increase the risk of disease progression in patients treated conservatively with Ho:YAG laser photoablation.

Preoperative quality of life questionnaires are an adequate tool to select women with genital prolapse for laparoscopic sacrocolpopexy.

INTRODUCTION AND HYPOTHESIS: No clear consensus exists on the selection of patients with pelvic organ prolapse (POP) for surgery. There is a need to preoperatively identify candidates who will benefit from surgery as there is no strict correlation between POP anatomical abnormalities and changes in symptoms and quality of life (QOL) after surgical treatment. Therefore, our objectives were to evaluate the changes in QOL after laparoscopic sacrocolpopexy (LSC) for POP using validated questionnaires and to assess their relevance in selecting women for surgery. METHODS: This was a prospective study of 48 women with advanced stages of POP treated by LSC from March 2005 to January 2015. We developed a recursive partitioning model from QOL PFDI-20 and PFIQ-7 questionnaire scores to determine a preoperative cut-off score for predicting improvement after surgery. The model was then validated in 84 consecutive women. RESULTS: Optimal anatomical results were obtained in 129 of the 132 women (97.7%). Both questionnaires revealed a significant improvement after LSC (p < 0.01). The probability of improvement after surgery was 0% in women with a preoperative PFIQ-7 score of <45.25, and 84% in women with a PFIQ-7 score of ≥45.25. The probability of improvement after surgery was 0% in women with a preoperative PFDI-20 score of <52.15, 88.2% in those with a PFDI-20 score of ≥ 98.45, and 42.9% in those with a PFDI-20 score between 52.15 and 98.45. In the validation set, the discriminatory accuracies of the model were 0.96 (95% CI 0.925-0.998) and 0.75 (95% CI 0.64-0.85) for the PFIQ-7 and PFDI-20 questionnaires, respectively. The performance was accurate with a significant difference between observed outcome frequencies and predicted probabilities (p = 1). CONCLUSIONS: Our results support the use QOL questionnaires to select women for LSC.

Comparison of Holmium:YAG and Thulium Fiber Lasers on the Risk of Laser Fiber Fracture.

OBJECTIVES: To compare the risk of laser fiber fracture between Ho:YAG laser and Thulium Fiber Laser (TFL) with different laser fiber diameters, laser settings, and fiber bending radii. METHODS: Lengths of 200, 272, and 365 µm single use fibers were used with a 30 W Ho:YAG laser and a 50 W Super Pulsed TFL. Laser fibers of 150 µm length were also tested with the TFL only. Five different increasingly smaller bend radii were tested: 1, 0.9, 0.75, 0.6, and 0.45 cm. A total of 13 different laser settings were tested for the Ho:YAG laser: six fragmentation settings with a short pulse duration, and seven dusting settings with a long pulse duration. A total of 33 different laser settings were tested for the TFL. Three laser settings were common two both lasers: 0.5 J × 12 Hz, 0.8 J × 8 Hz, 2 J × 3 Hz. The laser was activated for 5 min or until fiber fracture. Each measurement was performed ten times. RESULTS: While fiber failures occurred with all fiber diameters with Ho:YAG laser, none were reported with TFL. Identified risk factors of fiber fracture with the Ho:YAG laser were short pulse and high energy for the 365 µm fibers (p = 0.041), but not for the 200 and 272 µm fibers (p = 1 and p = 0.43, respectively). High frequency was not a risk factor of fiber fracture. Fiber diameter also seemed to be a risk factor of fracture. The 200 µm fibers broke more frequently than the 272 and 365 µm ones (p = 0.039). There was a trend for a higher number of fractures with the 365 µm fibers compared to the 272 µm ones, these occurring at a larger bend radius, but this difference was not significant. CONCLUSION: TFL appears to be a safer laser regarding the risk of fiber fracture than Ho:YAG when used with fibers in a deflected position.

The True Ablation Effect of Holmium YAG Laser on Soft Tissue.

PURPOSE: The holmium YAG (Ho:YAG) laser penetration depth (PD) of 0.4 mm has been widely described. Nonetheless, in physics, this concept refers to the tissue thickness at which 90% of the energy has been absorbed and not to the incision depth (ID) that the laser can achieve in tissue. The aim of this study is to evaluate the ablation efficiency of Ho:YAG laser on soft tissue. MATERIALS AND METHODS: With an automated robotic arm, systematic fissures were performed on flat veal kidney specimens. Broad setting spectrums from 2.5 to 80 W, short and long pulse, were tested with 272 and 365 µm laser fibers. Experiments were repeated three times. Two pathologists in a blinded manner measured the width, depth, and coagulation area with electronic microscopy. RESULTS: The overall mean ID was 2 mm (0.25-4.39) and the mean width was 1 mm (0.3-3.1). The mean coagulation thickness was 0.48 mm (0.25-1.73). The higher the frequency and energy, the deeper and wider was the incision p < 0.001. No differences were observed regarding the fiber diameter. The pulse length did not affect the ID, although the mean width was greater with short pulse p = 0.04. The outer mean coagulation was increased by increasing energy but not by increasing frequency p > 0.119. CONCLUSIONS: The overall mean ID was significantly higher than the theoretical 0.4 mm PD described for Ho:YAG laser. The energy, frequency, and pulse length had individual effects regarding ID, incision width, and coagulation. The ID should be specified in accordance with the laser's power output and should not be confused with the physics of PD concept.

Impact of the Curve Diameter and Laser Settings on Laser Fiber Fracture.

OBJECTIVE: To analyze the risk factors for laser fiber fractures when deflected to form a curve, including laser settings, size of the laser fiber, and the fiber bending diameter. MATERIALS AND METHODS: Single-use 272 and 365 µm fibers (Rocamed®, Monaco) were employed along with a holmium laser (Rocamed). Five different fiber curve diameters were tested: 9, 12, 15, 18, and 20 mm. Fragmentation and dusting settings were used at a theoretical power of 7.5 W. The laser was activated for 5 minutes and the principal judgment criterion was fiber fracture. Every test for each parameter, bending diameter, and fiber size combinations was repeated 10 times. RESULTS: With dusting settings, fibers broke more frequently at a curved diameter of 9 mm for both 272 and 365 µm fibers (p = 0.037 and 0.006, respectively). Using fragmentation settings, fibers broke more frequently at 12 mm for 272 µm and 15 mm for 365 µm (p = 0.007 and 0.033, respectively). Short pulse and high energy were significant risk factors for fiber fracture using the 365 µm fibers (p = 0.02), but not for the 272 µm fibers (p = 0.35). Frequency was not a risk factor for fiber rupture. Fiber diameters also seemed to be involved in the failure with a higher number of broken fibers for the 365 µm fibers, but this was not statistically significant when compared with the 272 µm fibers (p > 0.05). CONCLUSION: Small-core fibers are more resistant than large-core fibers as lower bending diameters (<9 mm) are required to break smaller fibers. In acute angles, the use of small-core fibers, at a low energy and long-pulse (dusting) setting, will reduce the risk of fiber rupture.

Laser Fiber and Flexible Ureterorenoscopy: The Safety Distance Concept.

INTRODUCTION: The costs of flexible ureterorenoscopes (fURSs) and their repair oblige the surgeon to know the proper handling of instruments. There is a lack of evidence in the literature about the safety distance that the laser fiber should have once out from the ureterorenoscope to avoid instrumental damages. MATERIALS AND METHODS: We performed an in vitro observational study. Seven fURSs were tested. The distance from the laser fiber tip and the fURS camera was measured at the first appearance on the endoscopic screen and when the fiber was reaching one-fourth of the screen. Second, to evaluate the impact of the holmium laser bubble according to different fiber distances, an assessment of the size and shape of the bubble created at the tip of the fiber with the laser activated was done, recording the images with a high-speed camera. RESULTS: The first appearance on the screen of the laser tip is different in different ureterorenoscopes. In all the ureterorenoscopes, we observed that when the laser fiber was at » of the screen, the bubble was never touching the fURS tip. CONCLUSION: Even if there is a big limitation of this study due to the impossibility to measure and to evaluate the damage of the fURS tip surface, we observed that when the laser fiber tip reaches » of the screen, the bubble generated by laser activation is never rebounding on the camera of the ureterorenoscope, preserving it from laser damages. We can define this position as the safety distance.

Immediate Nephroureterectomy or After Attempting Conservative Treatment, on Elective Indications, for Upper Urinary Tract Urothelial Carcinoma: Comparison of the Pathology Reports on a Retrospective Monocentric Study.

OBJECTIVE: Conservative treatment (CT) with flexible ureteroscopy and laser ablation is an alternative to radical nephroureterectomy (RNU) for the treatment of the upper urinary tract urothelial carcinoma (UTUC). The purpose of this study was to compare the pathology results obtained after immediate RNU or after attempt of CT for elective indication. PATIENTS AND METHODS: A retrospective study was conducted in a single tertiary center. All patients who had an RNU for urothelial carcinoma between 2007 and 2012 have been included. The patients were classified into two groups: group 1 is immediate RNU, and group 2 is RNU after CT (only elective indications). Preoperative data collected were as follows: age, sex, chronic kidney failure, radiological classification for cancer staging (TNM), tumor size, localization, and multifocal indication of CT. The pathological RNU data collected were tumor stage and grade. The T stage was divided into two groups (primary endpoint): pTa-T1-T2 and pT3-T4. The χ(2) test and Mann-Whitney was performed to compare the independent qualitative and quantitative variables, respectively. RESULTS: A total of 51 patients were included (40 patients in the immediate RNU group and 11 patients in the delayed RNU group after CT). Patients in both groups had comparable characteristics regarding age, sex, location, T stage, and preoperative tumor grade. On final pathology, 23 tumors were classified as pTa-T1-T2 in the immediate RNU group compared with 6 in the delayed RNU group. Seventeen and five tumors were classified as T3 in group 1 and group 2, respectively. These results were not significantly different between both groups (p=0.866). The pathological RNU grade was not significantly different between the groups. CONCLUSION: Within the limits of this retrospective study, the pathological RNU data showed no significant difference when RNU was done immediately or after CT for UTUC.