Superpulsed Thulium Fiber Laser for Stone Dusting: In Search of a Perfect Ablation Regimen-A Prospective Single-Center Study

Objective: To compare the efficacy of the standard and higher frequency regimens for superpulsed thulium fiber laser (SP TFL) retrograde intrarenal surgery (RIRS). Materials and Methods: A prospective study of patients with renal calculi of 10-30 mm was performed. For RIRS, we used the SP TFL (NTO IRE-Polus, Russia) and a 9.5F flexible ureteroscope with 270° deflection and 3.6F working channel. Retropulsion and visibility were assessed based on the surgeon's feedback using three-point Likert scales. The stone-free rate was assessed at 3 months with CT. Results: A total of 40 patients were included in the study with a mean age of 56 years, mean stone density of 880 ± 381 HU, mean stone size of 16.5 ± 6.8 mm, and median stone volume of 883 (interquartile range 606-1664) mm³. Both ablation efficacy and speed were higher in the 200-Hz mode (2.7 J/mm³ vs 3.8 J/mm³ and 5.5 mm³/second vs 8.0 mm³/second, respectively); moreover, the higher frequency correlated with increased ablation speed (r = -0.21, p = 0.019). However, both increased energy and frequency did not lead to increase of laser-on time or intraoperative complication rates. Conclusions: SP TFL is able to effectively disintegrate stones during RIRS with minimal complication rates. The use of higher frequency regimens showed higher efficacy and ablation speed and was not associated with increased complication rates.

The impact of the laser fiber-tissue distance on histological parameters in a porcine kidney model

PURPOSE

To evaluate the impact of the fiber-tissue distance on histological parameters in a porcine kidney model.

METHODS

Four lasers were tested at 60 W using a 600-µm bare-ended fiber: a continuous wave (cw) thulium fiber laser (TFL), a super pulsed (SP) TFL, a Ho:YAG laser, and a blue diode laser (BDL). All tissue samples were mounted on a motorized XY-translation stage. The fiber-tissue distance was changed within a range from 0to 6 mm. Ten incisions were made with each laser at each distance. Afterwards, the tissue samples were sliced with a microtome for lactate dehydrogenase staining to determine zones of thermal damage.

RESULTS

In contact mode, the largest incision depth was found for the cw TFL (1.7 ± 0.1 mm) compared to the SP TFL (1.0 ± 0.1 mm), BDL (0.9 ± 0.1 mm) and HoYAG laser (1.1 ± 0.1 mm), respectively. With regard to the coagulative properties, the SP TFL and the Ho:YAG laser showed comparable coagulation depths with 0.7 ± 0.1 and 0.6 ± 0.1 mm, respectively. At 2 mm fiber-tissue distance, the Ho:YAG laser was the only laser that vaporized tissue (incision depth: 0.2 ± 0.1 mm). The BDL was the only laser that caused coagulation at a distance of 3-5 mm.

CONCLUSION

Our results support the clinical observation that cw TFL must be defocused for best coagulation, while the coagulation depth of the SP TFL remains nearly constant within the range of 0-3 mm. Increasing the distance of the laser fiber to the tissue up to 5 mm did not cause significant differences with regard to coagulation depth using the BDL.

Safety and Short-Term Oncological Outcomes of Thulium Fiber Laser En Bloc Resection of Non-Muscle-Invasive Bladder Cancer: A Prospective Non-Randomized Phase II Trial

BACKGROUND: Ongoing efforts aim at overcoming the challenges of conventional transurethral resection of bladder tumor (TURBT) such as the high recurrence rate, difficulty of pathologic interpretation and complications including wall injury. OBJECTIVE: To prospectively assess the safety and efficacy of Thulium fiber en bloc resection of bladder tumor (Tm-fiber ERBT) compared to TURBT. MATERIALS AND METHODS: The prospective non-randomized study included 129 patients with non-muscle-invasive bladder cancer (NMIBC) divided into two groups: 58 patients underwent conventional TURBT and 71 –Tm-fiber ERBT with FiberLase U1 (NTO IRE-Polus, Russia). Relapse-free survival (RFS), detrusor presence and complication rates were assessed. For multivariable analysis we used the Pearson chi-squared Hosmer-Lemeshow goodness of fit test; to compare survival –Cox regression analysis; for operative data comparison –chi-square test with Fisher’s correction; for survival analysis –the Kaplan–Meier method and logrank test. RESULTS: RFS rates at 3 and 6 months were 84.5% and 67.2% for conventional TURBT versus 97.2% and 91.5% for Tm-fiber ERBT (p = 0.011 and p < 0.001, respectively). Detrusor muscle was present in 58.6% of cases treated with conventional TURBT vs 91.6% for the Tm-fiber ERBT group (p < 0.001). The obturator nerve reflex and bleeding were noted in 17.2% and 10.3% of TURBT cases, respectively; and in none of cases treated with Tm-fiber ERBT. Limitations included the non–randomized nature and the small sample size. CONCLUSIONS: Tm-fiber ERBT seems to be a safe and efficacious treatment option for NMIBC. Tm-fiber ERBT had fewer adverse events, was more likely to secure detrusor muscle in the specimen and resulted in better RFS rates than conventional TURBT. Based on these promising data, we have started a prospective randomized clinical trial comparing en bloc TURBT with conventional TURBT (ClinicalTrials.gov NCT03718754).

Active Surveillance for Intermediate-Risk Prostate Cancer: Systematic Review and Meta-analysis of Current Protocols and Outcomes

INTRODUCTION

Current guidelines allow active surveillance for intermediate-risk prostate cancer patients but do not provide comprehensive recommendations for selection. We performed a systematic review and meta-analysis of outcomes for active surveillance in intermediate- and low-risk groups.

METHODS

We performed a systematic literature search of intermediate-risk localized prostate cancer patients undergoing active surveillance using 3 literature search engines (Medline, Web of Science, and Scopus) over the past 10 years. The primary outcome was the percentage of patients who remain under surveillance. Secondary outcomes included cancer-specific survival, overall survival, and metastasis-free survival. For articles including both low- and intermediate-risk patients undergoing active surveillance, comparisons between the two groups were made.

RESULTS

The proportion of patients who remained on active surveillance was comparable between the low- and intermediate-risk groups after 10 and 15 years' follow-up (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.83-1.14; and OR, 0.86; 95% CI, 0.65-1.13). Cancer-specific survival was worse in the intermediate-risk group after 10 years (OR, 0.47; 95% CI, 0.31-0.69) and 15 years (OR, 0.34; 95% CI, 0.2-0.58). The overall survival rate showed no statistical difference at 5 years' follow-up (OR, 0.84; 95% CI, 0.45-1.57) but was worse in the intermediate-risk group after 10 years (OR, 0.43; 95% CI, 0.35-0.53). Metastases-free survival did not significantly differ after 5 years (OR, 0.55; 95% CI, 0.2-1.53) and was worse in the intermediate-risk group after 10 years (OR, 0.46; 95% CI, 0.28-0.77).

CONCLUSION

Active surveillance could be offered to patients with intermediate-risk prostate cancer. However, they should be informed of the need for regular monitoring and the possibility of discontinuation as a result of a higher rate of progression. Available data indicate that 5-year survival rates between intermediate- and low-risk patients do not differ; 10-year survival rates are worse. To assess the long-term effectiveness and safety of active surveillance, it is necessary to develop unified algorithms for patient selection and management, and to prospectively conduct studies with long-term surveillance.

Dual-Energy Computed Tomography for Stone Type Assessment: A Pilot Study of Dual-Energy Computed Tomography with Five Indices

Purpose: To assess the efficacy of dual-energy CT (DECT) in predicting the composition of urinary stones with a single index (dual energy ratio [DER]) and five indices. Methods: Patients undergoing DECT before active urolithiasis treatment were prospectively enrolled in the study. Predictions of stone composition were made based on discriminant analysis with a single index (DER) and five indices (stone density at 80 and 135 kV, Zeff [the effective atomic number of the absorbent material] of the stone, DER, dual-energy index [DEI] and dual-energy difference [DED]). After extraction, stone composition was evaluated by means of physicochemical analyses (X-ray phase analysis, electron microscopy, wet chemistry techniques, and infrared spectroscopy). Results: A total of 91 patients were included. For calcium oxalate monohydrate (COM) stones, the sensitivity, specificity, and overall accuracy of DECT with one index (DER) were 83.3%, 89.8%, and 86.8%, respectively; for calcium oxalate dihydrate (COD) and calcium phosphate stones-88.2%, 92.9%, and 91.2%, respectively; for uric acid stones-0%, 98.8% and 97.8%, respectively; for struvite stones-60%, 95.3%, and 93.4%, respectively. Discriminant analysis with five indices yielded the following sensitivity, specificity, and overall accuracy: 95.2%, 89.8%, and 92.3% for COM stones, 85.3%, 96.4%, and 92.3% for COD stones, and 100% in all three categories for both uric acid and struvite stones. Conclusions: DECT is a promising tool for stone composition assessment. It allowed for evaluation of chemical composition of all stone types with specificity and accuracy ranging from 85% to 100%. Five DECT indices have shown much better diagnostic accuracy compared to a single DECT index.

Thulium-fiber laser for lithotripsy: first clinical experience in percutaneous nephrolithotomy

PURPOSE

To evaluate the efficacy and safety of thulium-fiber laser (TFL) in laser lithotripsy during percutaneous nephrolithotomy (PCNL).

METHODS

Patients with stones < 30 mm were prospectively recruited to undergo PCNL using TFL "FiberLase" (NTO IRE-Polus, Russia). Stone size, stone density, operative time, and "laser on" time (LOT) were recorded. Study included only cases managed with fragmentation. Stone-free rate and residual fragments were determined on postoperative computer tomography. Complications were classified using the Clavien-Dindo grade. Stone retropulsion and endoscopic visibility were assessed based on surgeons' feedback using a questionnaire.

RESULTS

A total of 120 patients were included in the study with a mean age of 52 (± 1.8) years; of these 77 (56%) were males. Mean stone size was 12.5 (± 8.8) mm with a mean density of 1019 (± 375) HU. Mean operative time was 23.4 (± 17.9) min and mean LOT was 5.0 (± 5.7) min. Most used settings were of 0.8 J/25-30 W/31-38 Hz (fragmentation). The mean total energy for stone ablation was 3.6 (± 4.3) kJ. Overall stone-free rate was 85%. The overall complication rate was 17%. Surgeons reported stone retropulsion that interfered with surgery in 2 (1.7%) cases insignificant retropulsion was noted in 16 (10.8%) cases. Poor visualization was reported in three (2.5%) cases and minor difficulties with visibility in four (3.3%) cases.

CONCLUSIONS

TFL is a safe and effective modality for lithotripsy during PCNL and results in minimal retropulsion.

Extracorporeal ureter handling during laparoscopic pyeloplasty: tips and tricks for beginners

Introduction

Laparoscopic preparation of the ureter is a challenging part of upper urinary tract reconstruction, due to limited depth perception provided by the camera and lack of wristed motion of most laparoscopic instruments needed for adequate spatulation and scar tissue removal. One solution has been to perform the more difficult portions of the surgery in an extracorporeal manner. A hybrid intracorporeal-extracorporeal approach to upper tract ureteral reconstruction facilitates ureteral preparation at the stage of mastering the technique.

Material and methods

This retrospective study included 100 patients with primary ureteropelvic junction obstruction, who underwent laparoscopic pyeloplasty from 2014 to 2017. The patients were stratified into 2 groups: those who underwent conventional laparoscopic surgery and those who were managed with the hybrid approach. For the hybrid approach, externalizing the ureter to skin level required additional mobilization of the upper urinary tract.

Results

A total of 47 patients underwent conventional laparoscopic pyeloplasty and 53 - hybrid surgery. The maximum body mass index was 32. The hybrid approach was 8.5 minutes shorter compared to the conventional approach (p <0.001). No complications higher than Clavien-Dindo IIIb (n = 2) were observed (in both groups). Complete success (the resolution of pain and/or hydronephrosis) was observed in 92.5% in the hybrid group and in 95.7% in the conventional treatment group.

Conclusions

Hybrid pyeloplasty may be considered safe and effective. It has the advantage of making the surgery less challenging and time-consuming while offering improved precision. The advantages of the technique are particularly apparent during training. This technique can be recommended in the learning process of the surgeon.

Monopolar enucleation versus transurethral resection of the prostate for small- and medium-sized (< 80 cc) benign prostate hyperplasia: a prospective analysis

AIM

To assess efficacy and safety of monopolar enucleation of the prostate (MEP) and to compare it with the current treatment standard for medium-sized prostates, < 80 cc, transurethral resection of the prostate (TURP).

METHODS

A prospective analysis patients undergoing a surgical procedure for their diagnosis of BPH (benign prostatic hyperplasia) (IPSS > 20, Q_max < 10; prostate volume < 80 cc) was performed. IPSS, Q_max were assessed preoperatively, at 6 and 12 months postoperatively. The complications were classified according to the modified Clavien-Dindo grading system.

RESULTS

A total of 134 patients were included in the study: 70 underwent MEP and 64 - TURP for BPH (mean prostate volumes were comparable with p = 0.163). The mean surgery time was 44 min in the TURP group and 48.2 min in the MEP group, (p = 0.026). Catheterization time for MEP was 1.7 and 3.2 days for TURP (p < 0.001). Hospital stay for MEP was 3.2 days vs. 4.8 days for TURP (p < 0.001). Both techniques shown comparable efficiency in benign prostatic obstruction relief with IPSS drop in MEP from 23.1 to 5.9 and in TURP group from 22.8 to 7.3, whereas Q_max increased from 8.2 to 20.5 after MEP and from 8.3 and 19.9 after TURP. Urinary incontinence rate after catheter removal in TURP group was 9.0% and 7.8% in MEP group, at 1 year follow-up, it was 1.4% and 3.1% in MEP and TURP, respectively (p = 0.466).

CONCLUSIONS

Our experience demonstrated that MEP is an effective and safe BPH treatment option combining the efficacy of endoscopic enucleation techniques and accessibility of conventional TURP.

Impact of endoscopic enucleation of the prostate with thulium fiber laser on the erectile function

Background

The impact of number of endoscopic enucleation of the prostate techniques (holmium laser enucleation - HoLEP for example) on erectile function have already been investigated. However, the thulium-fiber laser, in this setting remains unstudied. In this study, we compared sexual function outcomes in patients with benign prostatic hyperplasia (BPH) treated with transurethral resection of the prostate (TURP) or thulium-fiber laser enucleation (ThuFLEP).

Methods

We performed a retrospective analysis of patients who underwent transurethral resection and endoscopic enucleation of the prostate for BPH; inclusion criteria was the presence of infravesical obstruction (IPSS > 20, Qmax < 10 mL/s). Erectile function (EF) was assessed using the International Index of Erectile Function (IIEF-5) both prior to endoscopic examination, and six months after.

Results

A total of 469 patients with BPH were included in the study; of these, 211 underwent to ThuFLEP, and 258 TURP. Preoperative IIEF-5 in TURP and ThuFLEP groups were 11.7 (±4.5) and 11.1 (±5.0), respectively (p = 0.17). At six month the IIEF-5 score was unchanged (p = 0.26 and p = 0.08) and comparable in both groups (p = 0.49). However, mean IIEF-5 score shown significant increase of 0.72 in ThuFLEP group, comparing to decrease of 0.24 in TURP patients (p < 0.001).

Conclusions

Both TURP and ThuFLEP are effective modalities in the management of infravesical obstruction due to BPH. At six months follow-up after surgery, both techniques lead to comparable IIEF-5 score. However, our results demonstrated that the ThuFLEP is more likely to preserve the erectile function leading to increase of IIEF-5 at six months in contrast to TURP which lead to slight drop in IIEF-5 score.

A Randomized Trial Comparing The Learning Curve of 3 Endoscopic Enucleation Techniques (HoLEP, ThuFLEP, and MEP) for BPH Using Mentoring Approach-Initial Results

OBJECTIVE

To assess the differences in the learning curve associated with different techniques of endoscopic enucleation of the prostate.

MATERIALS AND METHODS

Ninety patients were randomly assigned into 3 groups (30 patients in each): HoLEP, ThuFLEP or MEP. Inclusion criteria for the study included prostate volume <80 cc, IPSS > 20, or Qmax < 10. The EEPs were performed by 3 surgeons experienced in transurethral resection of the prostate. Assignment of surgeons to surgical technique was also randomized. None of the surgeons had prior experience in EEP.

RESULTS

ThuFLEP was slightly superior (with no significant difference [P > .05]) to HoLEP and MEP in terms of overall enucleation rate-1.0 g/min vs 0.8 g/min and 0.7 g/min, respectively. We observed similar enucleation rates at the initial stages of training (first 20 surgeries) with insignificant increase in ThuFLEP efficiency. At next 10 surgeries ThuFLEP and HoLEP efficiency were higher than of MEP (P < .001) without significant difference between techniques of laser EEP (P = .07).

CONCLUSION

Endoscopic enucleation of the prostate can be adopted safely and effectively within 30 surgeries if the technique is learned with a mentoring approach. EEP is shown to be safe and effective even in the initial stages of learning. Laser EEP (HoLEP, ThuFLEP) appears to lend itself to quicker adaptation compared MEP.