Mathias Sørstrand Æsøy

Objective: Thulium fibre laser (TFL) offers a wide range of power settings during ureteroscopic (URS) lithotripsy, yet the impact of power selection on intraoperative laser‐use dynamics remains unclear. The objective of this study was to characterise differences in laser activation patterns between low‐power (LP) and high‐power (HP) TFL during sheathless URS. Materials and Methods: This was a predefined secondary analysis of intraoperative laser data collected during a randomised clinical trial comparing LP (0.4–0.6 J × 10 Hz; 4–6 W) and HP (0.4–0.8 J × 20–40 Hz; 16–18 W) TFL URS lithotripsy. Flexible URS was performed without a ureteral access sheath. Laser system logs provided time‐stamped activation and pause events with microsecond precision. Laser‐use dynamics were characterised using a predefined set of complementary metrics, including active laser time (ALT), laser operating time (LOT), total activation count, activation durations, pause durations and operator duty cycle (ODC = ALT/LOT). Group comparisons used Holm–Bonferroni–adjusted p values. Results: Data from 72 LP and 74 HP procedures were analysed. ALT was longer with LP (23 vs. 13 min; p < 0.001), whereas LOT was similar (31 vs. 30 min; p = 0.194). LP had a lower activation count (55 vs. 89; p < 0.001) and longer activations (median 24 s vs. 7 s; p < 0.001). Empirical cumulative distribution function analysis showed 89.4% of LP activations lasted ≤30 s compared with 97.2% for HP ( p < 0.001). Total pause time was shorter in LP (8 vs. 14 min; p < 0.001), resulting in a higher ODC (73% vs. 49%; p < 0.001). Conclusion: LP and HP TFL lithotripsy result in distinctly different laser‐use dynamics during sheathless URS. LP supported sustained, continuous lasing, whereas HP yielded fragmented activation requiring frequent pauses. Coupled with superior stone‐free outcomes in the parent trial, these findings suggest that preserving clear endoscopic visibility and more active lasing may be more impactful than increasing laser power.

Objective: To compare operative time and clinical outcomes between high‐power (HP) and low‐power (LP) thulium fibre laser (TFL) ureteroscopic (URS) lithotripsy for renal stones. Patients and methods: Single‐centre, randomised trial (1:1) at Haukeland University Hospital, Norway. Adults undergoing day‐case URS for 8–25 mm renal stones were enrolled. A total of 150 cases were included. Patients were randomised to URS lithotripsy with TFL using HP (16–18 W, selected for thermal safety during sheathless URS) or LP (4–6 W). The primary endpoint was operative time. The secondary endpoints were stone‐free rate (SFR) on 3‐month non‐contrast computed tomography (Grade A: no residuals; Grade B: ≤2 mm; Grade C: ≤4 mm; Grade D: >4 mm), laser metrics, performance measures, and complications according to the Clavien–Dindo Classification. Groups were compared using appropriate parametric and non‐parametric tests (two‐sided α = 0.05). Results: A ureteric access sheath was not used in any case, reflecting routine practice at our centre. The operative time did not differ between arms: median (interquartile range) HP 48 (36–62) vs LP 54 (42–65) min ( P = 0.12). HP used more energy (12 vs 7 kJ, P < 0.001) with shorter active laser time (13 vs 24 min, P < 0.001), but laser operating time was similar. SFRs favoured LP compared to HP: Grade A, 63% vs 44% ( P = 0.02); Grade B, 77% vs 56% ( P = 0.008). The Grade C SFR was similar between arms. LP was also associated with better surgeon‐rated endoscopic visibility and fewer minor postoperative complications (11% vs 37%, P < 0.001). Major complications (Clavien–Dindo Grade ≥III) were uncommon and similar between arms. Conclusion: Using HP did not shorten the operative time. LP improved SFRs for Grade A/B and reduced minor postoperative morbidity, supporting LP as the default TFL strategy for sheathless URS lithotripsy.

Introduction: Ureteroscopy has become increasingly chosen as a treatment of choice for patients with kidney stone disease and laser as the energy source for stone lithotripsy is a key part of this. Our aim was to analyse a national database to evaluate the burden of adverse events related to laser fibers and laser machines.Methods: Search was performed of the Manufacturer User and Facility Device Experience (MAUDE) database in the United States for all events related to holmium laser fibers and holmium laser machines during ureteroscopy between 2012-2021. Information collected included the following: problem, timing, prolonged anaesthesia, early termination of procedure, injury and retained parts.Results: 699 holmium laser fiber events were reported and these had been manufactured by 13 different companies. The commonest problems were breakage outside the patient while in use (26.3%) and breakage of the laser fiber tip (21.2%). Manufacturers concluded root cause to be device failure in 8.9%. 29% of issues occurred before the laser had been activated. 5.2% of cases had to be cancelled as a result of an event. Significantly more injuries were sustained intra-operatively by operating staff compared to patients (6% vs. 0.2%, p < 0.001). All these injuries were superficial burns to the skin with the hand being the most affected body part (88.1%). Zero ocular injuries were reported. Only eight events were related to laser machines and all involved sudden hardware failure but no patient injury.Conclusions: Laser fibers are fragile. Most adverse events are due to operator error. Direct patient injury from laser fiber is scarce but operating staff should be aware of the risk of sustaining minor burns. Laser machines rarely incur problems and, in this study, did not result in any safety issues beyond need to abort the procedure due to lack of spare equipment.

Introduction: Kidney stones in pregnant is not a common emergency, but it is one that is extremely challenging to manage. There exists no previous survey, which maps the different practice patterns adopted. Our aim was to deliver a survey to evaluate the current status of practice patterns across different parts of the world regarding the management of stone disease in pregnancy. Methods: Through an iterative process, 19-item survey was devised. This contained the following five sections: (1) Demographics, (2) General items, (3) Diagnosis and Imaging, (4) Initial management, (5) Surgery. It was disseminated via social media and email chains. Results: A total of 355 responses were collected, and the majority (66.2%) reported no established hospital protocol for stones in pregnancy. Ultrasound was the most popular first line imaging choice (89.9%) but 8% would choose non-contrast CT. The latter was also chosen as second line choicer in 34.6% as opposed to magnetic resonance imaging. A large proportion (42.5%) had requested CT in pregnancy previously. With equivocal ultra sound results, only 19.4% would proceed to ureteroscopy (URS) but 40.9% would opt for CT. Twenty-four–48 hours were the most popular (37.6%) time period to observe before surgical intervention. Ureteral stent and nephrostomy were regarded as equally effective, and 6 weeks was most popular frequency for an exchange. Most do not use fetal heart rate monitoring intraoperatively. A total of 3.94% had previously performed percutaneous nephrolithotomy during pregnancy. Conclusion: Practice patterns vary widely for suspected kidney stones in pregnancy and use of CT appears increasingly popular. This includes when faced with equivocal ultrasound results and instead of proceeding to ureteroscopy. Most hospitals lack an established management protocol for this scenario.

Background: Ureteropelvic junction obstruction (UPJO) is characterised by stenosis of the ureteral lumen at the level of the renal pelvis and proximal ureter. At Haukeland University Hospital, robotic-assisted laparoscopic pyeloplasty (RLP) for UPJO has been performed since 2014. The aim of this study was to evaluate the results of the treatment and consider what determines treatment success. Materials and methods: Retrospective review was performed of consecutive patients undergoing RLP between 2014-2022. Outcomes of interest included symptom relief, complication rates and renographic findings at follow-up. Treatment success was defined in terms of symptom improvement and/or improvement as well as relief of obstruction on renography. Results: In total, 95 RLPs were performed in 54 women and 41 men, with a mean age of 40 years (IQR: 21-58). Flank pain was the most frequent presenting complaint (n = 81, 85%) followed by infection (n = 33, 35%). More than one indication for surgery was present in 1/3 of the patients. Urodynamic relevant obstruction on renography was found in 62 patients (65%) preoperatively. Mean operative time was 123 minutes (range 60-270). Two patients experienced minor intraoperative complications. At three months follow-up, 91% of patients had symptom relief, and no obstruction on renography was recorded in 64%. There was no significant association between improvement in symptoms and renography findings at follow-up, p = 1. Conclusions: RLP can deliver a high success rate in terms of symptom relief and few complications. There was no association between renography findings and symptom relief at follow-up. Success after surgery should be determined by symptom relief rather than renography findings.

Objective: The primary aim of the study was to explore intrarenal temperatures (IRTs) during flexible ureteroscopic laser lithotripsy (FURSL). The secondary aim was to investigate the correlation between temperatures and renal pelvis anteroposterior diameter (APD). Materials and Methods: From February 2023 to June 2023, 10 patients with an indwelling nephrostomy tube (NT) undergoing FURSL were enrolled in the study. Sheathless FURSL was performed using gravitational irrigation (23°C) at 60 cm. A sterile K-type thermocouple was inserted through the NT. Temperatures were recorded for 120 seconds with continuous laser activation and for another 60 seconds after deactivation. Thulium fiber laser delivered energy using a 150 μm fiber and incremental power settings of 5, 10, 20, and 30 W. The laser was deactivated whenever the IRT reached 43°C. Results: IRT correlated directly to power settings. Each time the power settings were increased, the temperature rose significantly. The increase in average peak temperature was 2.6°C between 5 and 10 W ( p < 0.001), 3.4°C between 10 and 20 W ( p < 0.001), and 2.5°C between 20 and 30 W ( p < 0.001). Temperatures reached 43°C in three patients applying 20 W and in eight patients applying 30 W. The shortest activation-time until threshold was 12 and 28 seconds with 30 and 20 W settings, respectively. When reaching 43°C, temperatures remained above this threshold for an additional 29 seconds on average. There was a significant correlation between IRT and renal APD. For example, when 10 W was applied in the setting of APD ≤20 mm, the recorded temperature was on average 2.3°C higher compared with APD >20 mm, with the same power settings applied, p < 0.001. Conclusion: During FURSL, IRT correlates directly with power settings and is inversely correlated with renal pelvic APD. Using a sheathless approach, power settings ≥20 W should arguably be avoided, especially in the context of a nondilated renal pelvis. ClinicalTrials: The study was registered on ClinicalTrials.gov (NCT05677425).

Ureteroscopy has undergone many advances in recent decades. As a result, it is able to treat an increasing range of patient groups including special populations such as pregnancy, anomalous kidneys and extremes of age. Such advances include Holmium laser, high-power systems and pulse modulation. Thulium fibre laser is a more recent introduction to clinical practice. Ureteroscopes have also been improved alongside vision and optics. This article provides an up-to-date guide to these topics as well as disposable scopes, pressure control and developments in operating planning and patient aftercare. These advances allow for a custom strategy to be applied to the individual patient in what we describe using a new term: Tailored endourological stone treatment (TEST). Level of evidence: 5

The aim of this study was to investigate temperature profiles in both the renal pelvis and parenchyma during Thulium Fiber Laser (TFL) and Holmium:yttrium-aluminium-garnet (Ho:YAG) laser activation...