Impact of preoperative ureteral stenting on stone-free rates of ureteroscopy for nephroureterolithiasis: a matched-paired analysis of 286 patients

Impact of surgical experience on stone-free rates of ureteroscopy for single urinary calculi of the upper urinary tract: a matched-paired analysis of 600 patients

INTRODUCTION

To evaluate the impact of surgical experience on ureteroscopic stone-free rates (SFR) and complication rates (CR) for the treatment of urinary calculi of the upper urinary tract.

METHODS

We evaluated retrospectively, patients (n=300) having undergone ureteroscopy (URS) for single urinary calculi treated by residents (n=12) at our department over a 6-year period. These patients were matched according to age, gender, body-mass index, and stone side/size/site with patients (n=300) treated by consultants (n=5) of our department during the same period. Patient data, primary SFR, and CR were compared.

RESULTS

The mean±standard deviation (range) stone size was 6.39±3.26 (2-20) mm. The primary SFR after one URS procedure was 95.2% and did not differ between residents and consultants (95% vs 95.3%, p=0.489). The SFR were 95.9% and 98.5% for ureteral stones (p=0.125) and 93.2% and 89.3% for kidney stones (p=0.298) in the resident and consultant group, respectively. The SFR differed significantly between ureteral and kidney stones (97.2% vs 91.3%, p≤0.001). Perioperative complications occurred in a total of 63 patients (10.5%): Clavien 1: 3.8%, Clavien 2: 2%, Clavien 3a: 1.8%, and Clavien 3b: 2.8%, respectively. There were no differences in the total CR between residents (12%) and consultants (9%) (p=0.2116). However, the ureteral perforation rate was significantly higher in residents compared with consultants (4.3% vs 1.3%, p≤0.027).

CONCLUSIONS

URS is a safe and efficacious procedure for the treatment of single urinary calculi. Resident status does not compromise the SFR after ureteroscopic treatment of single urinary calculi. However, the incidence of ureteral perforation was associated with surgeon's experience.

Clinical factors prolonging the operative time of flexible ureteroscopy for renal stones: a single-center analysis

The objective of the study was to evaluate the clinical factors affecting the operative time of flexible ureteroscopy (fURS). We retrospectively evaluated 233 patients with renal stones who had been treated successfully and had stone-free status 3 months after fURS and holmium laser lithotripsy between December 2009 and December 2013 at a single institute. Operative time was divided into three periods (total, before fragmentation, and after starting fragmentation), and associations between possible factors and these periods were analyzed by a multivariate logistic regression model with backward selection. The mean total operative time was 74.0 ± 32.0 min. There were significant differences in the following clinical factors: sex, body height, stone volume, maximum and mean Hounsfield units (HUs), diameter of the ureteral access sheath, and experience of the surgeon, between patients who underwent procedures with a total operative time of less or more than 90 min. A multivariate assessment revealed four independent factors influencing total operative time (P < 0.05): stone volume (P < 0.001), experience of the surgeon (P < 0.001), maximum HUs (P = 0.014), and lack of preoperative stenting (P = 0.027). Larger stone volume, lower experience level of the surgeon, higher HUs, and the absence of preoperative stenting were identified as parameters prolonging the total operative time of fURS and, in particular, the operative time after starting fragmentation. On the other hand, operative time before starting fragmentation, which represented the time required to identify the stone by ureteroscopy and insert the access sheath, was more difficult to predict preoperatively.

Balloon Dilation of the Ureter: A Contemporary Review of Outcomes and Complications

PURPOSE

During ureteroscopy ureteral balloon dilation may be necessary to allow for passage of endoscopic instruments or access sheaths. We assessed the efficacy and complications associated with ureteral balloon dilation.

MATERIALS AND METHODS

We retrospectively reviewed the records at 2 institutions from 2000 to 2012 to identify patients who underwent ureteral balloon dilation during ureteroscopic treatment of upper tract stones. An 18Fr balloon dilator was used in all cases. Patients with documented ureteral stricture, radiation therapy or urothelial cancer were excluded from analysis. Primary outcomes were the stone-free rate, operative complications, balloon dilation failure and the postoperative ureteral stricture rate. Complications were divided into intraoperative and postoperative groups according to the Satava and Clavien-Dindo classifications, respectively.

RESULTS

A total of 151 patients fulfilled study criteria. Median followup was 12 months. The stone-free rate was 72% and median time to first postoperative imaging was 2.8 months. Balloon dilation failed in only 8 patients (5%). Eight intraoperative ureteral perforations (5%) were identified, which were managed by a ureteral stent in 7 patients and a percutaneous tube in 1. Endoscopic re-treatment was required in 4 patients with Satava 2b postoperative complications. The postoperative complication rate was 8% (11 cases). A single ureteral stricture was attributable to balloon dilation.

CONCLUSIONS

In this contemporary review balloon dilation of the ureter before endoscopic treatment of stone disease was associated with a high success rate and few complications. Ureteral balloon dilation may decrease the need for a secondary procedure in patients undergoing ureteroscopy to manage proximal ureteral and intrarenal stones.

Is Prolonged Operation Time a Predictor for the Occurrence of Complications in Ureteroscopy?

OBJECTIVE

To determine the impact of duration of ureteroscopy for urolithiasis on complication rates (CRs) of the procedure.

METHODS

A retrospective analysis of 2,010 patients, treated between 2006 and 2011, was done. The operation time (OT) and the occurrence of complications were compared.

RESULTS

The overall CR was 14.3% [298 complications, minor complications (Clavien I-II) 91.7%]. The median OT was 35 min [interquartile range (IQR) 20-61]. The OT differed significantly between those without complications [34 min (IQR 20-60)] and those with complications [45 min (IQR 25-76)] (p < 0.0001). The correlation between the OT and the occurrence of complications (r = -0.009648, p < 0.0001) was very weak and passed the level of significance (r = 0.2). The effect size was of minor relevance (Cohen's d = 0.27972).

CONCLUSIONS

Longer OT correlates significantly with a higher CR. The effect is however shown to be minor and the overall rate of complications, especially severe ones, is low.

Disposable devices for RIRS: where do we stand in 2013? What do we need in the future?

PURPOSE

Disposable devices for retrograde intrarenal surgery (RIRS) form a significant part of the urologist's armamentarium for the endoscopic management of urologic diseases. Herein, we provide an overview of the literature regarding the advances and controversies of these devices.

METHODS

A PubMed search was used to identify the literature discussing the subject of disposable devices for RIRS. Articles published between 2012 and 2013 were considered.

RESULTS

Ureteral access implements including access sheaths, wires, and dilators are an area of both improvement and controversy regarding their proper use. The safety, effectiveness, and limitations of lithotrites continue to be refined. Stone retrieval devices are undergoing persistent miniaturization, and their use may prove to be cost effective. The debate over perioperative stenting remains, while symptom management is explored. A cost-effective option for disposable flexible ureteroscopy shows promise.

CONCLUSIONS

While rapid advances in technology and knowledge continue, continual improvements are necessary. Disposable equipment needs persistent refinement and possible miniaturization. More efficient fragment retrieval devices are needed. Durability of laser fibers and safety within ureteroscopes needs to be improved. Reducing stent morbidity remains an ongoing challenge. Lastly, costs need to be reduced by the further development of disposable flexible ureteroscopes and in the recyclability of disposable devices to improve availability worldwide.

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.

[Calyceal stones]

The natural course of untreated, asymptomatic calyceal calculi has not yet been clearly defined regarding disease progression and risk of surgical interventions. The decision for an active treatment of calyceal calculi is based on stone composition, stone size and symptoms. Extracorporeal shockwave lithotripsy (ESWL) has a low complication rate and is recommended by the current guidelines of the German (DGU) and European (EAU) Associations of Urology as a first-line therapy for the treatment of calyceal stones <2 cm in diameter. However, immediate removal of stones is not achieved with ESWL. The primary stone-free rates (SFR) after ESWL depend on stone location and stone composition and can show remarkable differences. Minimally invasive procedures, such as percutaneous nephrolitholapaxy and ureteroscopy are alternatives for the treatment of calyceal stones which have low morbidity and high primary SFR when performed in centres of excellence.

Combined semirigid and flexible ureterorenoscopy via a large ureteral access sheath for kidney stones >2 cm: a bicentric prospective assessment

PURPOSE

The international guidelines on urolithiasis state that the percutaneous approach is superior for kidney stones ≥20 mm. Nevertheless, several groups have reported high stone-free rates (SFRs) with low morbidity for ureteroscopic treatment of calculi >15 mm. We hereby describe a new technique including the combined use of semirigid and flexible ureteroscopy via a large ureteral access sheath (UAS).

METHODS

The proposed technique includes (a) preoperative ureteral stenting, (b) use of a large lumen UAS (14/16F, 35 cm), (c) use of a semirigid ureteroscope, (d) holmium laser lithotripsy, (e) passive and (f) active fragment extraction, and finally, the removal of caliceal stones (g) using a flexible scope. We conducted a prospective outcome analysis for 38 patients treated at two tertiary university centers.

RESULTS

Perioperative data were as follows: median cumulative stone size 24.5 mm (20-60), median operating time 95 min (50-205), post-operative ureteral stenting (2-35 days) in 33 patients (86.8 %), Clavien complications 2 and 3 in 7.9 %, primary SFR 63.2 %, and overall computed tomography (CT) controlled SFR after 3 months 81.8 % (including staged procedures). No late complications were observed.

CONCLUSIONS

The combined use of semirigid ureteroscopy and an UAS further develops the endoscopic treatment of kidney stones. This is the first series of this kind that confirms high SFRs by CT. The approach has significant advantages: Superior irrigation and outflow enhance both vision and stone clearance, and multiple ureteral passages without putting the ureter at injury risk. These encouraging results make this modality an appealing alternative to percutaneous nephrolithotomy.