Systematic evaluation of a holmium:yttrium-aluminum-garnet laser lithotripsy device with variable pulse peak power and pulse duration

AbstractObjectiveThe Holmium:yttrium-aluminum-garnet (Ho:YAG) laser is the standard lithotrite for ureteroscopy. This paper is to evaluate a Ho:YAG laser with a novel effect function in vitro, which allows a real-time variation of pulse duration and pulse peak power.MethodsTwo types of phantom calculi with four degrees of hardness were made for fragmentation and retropulsion experiments. Fragmentation was analysed at 5 (0.5 J/10 Hz), 10 (1 J/10 Hz), and 20 (2 J/10 Hz) W in non-floating phantom calculi, retropulsion in an ureteral model at 10 (1 J/10 Hz) and 20 (2 J/10 Hz) W using floating phantom calculi. The effect function was set to 25%, 50%, 75%, and 100% of the maximum possible effect function at each power setting. Primary outcomes: fragmentation (mm3), the distance of retropulsion (cm); ≥5 measurements for each trial.ResultsAn increase of the effect feature (25% vs. 100%), i.e., an increase of pulse peak power and decrease of pulse duration, improved Ho:YAG laser fragmentation. This effect was remarkable in soft stone composition, while there was a trend for improved fragmentation with an increase of the effect feature in hard stone composition. Retropulsion increased with increasing effect function, independently of stone composition. The major limitations of the study are the use of artificial stones and the in vitro setup.ConclusionChanges in pulse duration and pulse peak power may lead to improved stone fragmentation, most prominently in soft stones, but also lead to increased retropulsion. This new effect function may enhance Ho:YAG laser fragmentation when maximum power output is limited or retropulsion is excluded

Ureteroscopy in pregnant women with complicated colic pain: Is there any risk of premature labor?

Objective: Clinical presentation of ureteral stones during pregnancy is generally with renal colic pain. The aim of this study is to present our experience in the management of renal colic during pregnancy in emergency settings. Materials and methods: 208 pregnant patients who presented to emergency department with renal colic pain and underwent ureteroscopy (URS) due to failed conservative therapy were enrolled in the study. Urinary tract stones were diagnosed either with ultrasound (US) examination or during URS. Laser lithotripsy and double J (DJ) stent placement were routinely done in all patients with ureteral stones. The incidence of infective complications and premature uterine contractions (PUC) due to URS were compared. Results: No stone was identified in 36.1% (n = 75) of patients with using US and diagnostic URS. Of the remaining 133 patients, 30 (22.6%) had no stone at US but stones were diagnosed during diagnostic URS. The type of anesthesia had no significant effect on PUC. An increased risk of sepsis and PUC was found in patients with fever at the initial presentation. Interestingly, PUC was more frequent in patients with lower serum magnesium levels. There was a significant correlation with time delay until the intervention and the risk of urosepsis and PUC, individually. Conclusions: Ureteroscopy is a safe option for evaluation of pregnant patients with unresolved renal colic. According to the current findings, timing of the operation is the most important factor affecting the septic risks and abortion threat. Surgical intervention with URS must be planned as soon as possible

A prospective, randomized comparison of a 1940 nm and a 2013 nm thulium: yttrium-aluminum-garnet laser device for Thulium VapoEnucleation of the prostate (ThuVEP): First results

Introduction: We report the early postoperative results of the first prospective, randomized comparison of two commercially available thulium lasers with different wavelengths for the treatment of benign prostatic obstruction (BPO). Materials and Methods: From January to June 2013, 80 consecutive patients were randomized for Thulium VapoEnucleation of the prostate (ThuVEP) with a 2013 nm (RevoLix ® ) (n = 39) or a 1940 nm (Vela ® XL) (n = 41) thulium laser. Preoperative status, surgical details and the immediate outcome were recorded for each patient. The perioperative complications were assessed and classified according to the modified Clavien classification system. Results: Median operation time, resected tissue, percentage of resected tissue, catheter time, overall operation efficiency and Hb loss differed nonsignificantly between both devices (P > 0.05). At discharge, the median maximum urinary flow rate and postvoiding residual (PVR) urine improved significantly in both groups (P < 0.001). The PVR was lower in the 1940 nm ThuVEP group (P ≤ 0.034). Perioperative complications occurred in 18 (22.5%) patients (Clavien 1: 12.5%; Clavien 2: 5%, Clavien 3b: 2.5%, Clavien 4a: 2.5%), with no differences between the groups (P = 0.5). Conclusions: The 1940 nm and the 2013 nm thulium lasers are both safe and effective for the treatment of BPO with ThuVEP. Both lasers give equivalent and satisfactory immediate micturition improvement with low perioperative morbidity

Managing caliceal stones

The natural course of untreated asymptomatic caliceal calculi has not been clearly defined, especially in terms of disease progression, and the indications for and outcomes of surgical intervention are not precise. Caliceal stones may remain asymptomatic but, in case of migration, ureteral calculi can cause acute ureteric colic with severe complications. The decision for an active treatment of caliceal calculi is based on stone composition, stone size and symptoms. Extracorporal shock-wave lithotripsy (ESWL) has a low complication rate and is recommended by the current guidelines of the European Association of Urology as a first-line therapy for the treatment of caliceal stones <2 cm in diameter. However, immediate stone removal is not achieved with ESWL. The primary stone-free rates (SFR) after ESWL depend on stone site and composition and, especially for lower pole calculi, the SFR differ widely from other caliceal stones. Minimally-invasive procedures including percutaneous nephrolithotomy and ureteroscopy are alternatives for the treatment of caliceal stones, associated with low morbidity and high primary SFR when performed in centers of excellence

Outcomes of ureteroscopy for stone disease in anomalous kidneys: a systematic review

Introduction: Treatment of stone disease in anomalous kidneys can be challenging. As ureteroscopy (URS) has advanced, the number of studies reporting on outcomes of URS for stone disease in anomalous kidneys has increased. Our objective was to perform a systematic review of the literature to evaluate the outcomes of URS for stone disease in this group of patients. Methods: A Cochrane style review was performed in accordance with the PRISMA guidelines using Medline, EMBASE, CINAHL, Cochrane Library, Scopus and individual urologic journals for all English language articles between inception and June 2018. Results: Fourteen papers (413 patients) with a mean age of 43 years and a male to female ratio of 285:128 were included. The underlying renal anomaly was horseshoe kidney (n = 204), ectopic kidney (n = 117), malrotation (n = 86), cross fused ectopia (n = 2) and others (n = 2). With a mean stone size of 16 mm (range 2–35 mm), the majority of stones were in the lower pole (n = 143, 34.6%) or renal pelvis (n = 128, 31.0%), with 18.9% (n = 78) having stones in multiple locations. Treatment modality included the use of flexible ureteroscope in 90% of patients and ureteral access sheath used in 11 studies. With a mean operative time of 61.3 min (range 14–185 min), the initial and final SFR was 76.6% (n = 322) and 82.3% (n = 340), respectively. The overall complication rate was 17.2% (n = 71), of which 14.8% were Clavien I/II and the remaining 2.4% were Clavien ≥ III complications. Conclusion: Although ureteroscopy in patients with anomalous kidneys can be technically challenging, advancements in endourological techniques have made it a safe and effective procedure. In these patients the stone-free rates are good with a low risk of major complications.</p