Infective complications after retrograde intrarenal surgery: a new standardized classification system

Investigation of Predictors of Systemic Inflammatory Response Syndrome After Endourological Procedure of Upper Urinary Tract Stones

Background: In order to prevent infectious complications following endourological procedure of upper urinary tract stones, it is essential to determine which patients are at high risk of developing this complication. We aimed to identify predictors that may cause systemic inflammatory response syndrome (SIRS) after the endourological procedure of upper urinary tract stones. Materials and Methods: Patients who underwent percutaneous nephrolithotomy (PNL), flexible ureteroscopy (F-URS), or semirigid ureteroscopy (SR-URS) in our center between January 2011 and June 2020 were evaluated retrospectively. After surgery, patients were pursued for SIRS criteria. Logistic regression analyses were applied to identify predictors of SIRS. Results: A total of 1471 patients were included in the study. The rates of SIRS after PNL, F-URS, and SR-URS were 12.9%, 6.3%, and 1.7%, respectively. In multivariate analysis, predictors for SIRS were determined to be stone volume, operative time, and history of recurrent urinary tract infection (UTI) in the PNL group; ipsilateral stone surgery history, stone volume, and operative time in the F-URS group; and stone volume, operative time, and history of recurrent UTI in the SR-URS group. Conclusion: Stone volume and operative time were determined to be independent predictors of SIRS in endourological surgery of upper urinary tract stones.

Prospective Evaluation of Risk Factors Responsible for Infection Following Retrograde Intrarenal Surgery

OBJECTIVE

The study aimed to identify the various risk factors for infective complications following retrograde intrarenal surgery (RIRS).

MATERIALS AND METHODS

The study was conducted over one year, and the incidence of infectious complications after RIRS was calculated. Patients were divided into two groups based on the presence and absence of infective complications and were compared in terms of preoperative and operative characteristics. The complications were assessed and graded according to the Modified Clavien classification system (MCCS). The Fisher's exact test, Student's t-test, and Mann-Whitney U test were used for univariate analysis. Multivariate logistic regression analysis was used to identify independent risk factors for postoperative urinary tract infection (UTI).

RESULTS

Out of 165 patients in the study, 27 (16.7%) patients developed UTI within one month of undergoing RIRS. The most frequent complication was fever, which occurred in 13 (7.8%) patients. When stratified by MCCS, 13 were grade I, nine were grade II, four were grade III, and one was a grade IV complication. High stone burden, concomitant diabetes mellitus, and multiple renal stones were identified as substantial risk factors for postoperative UTI in univariate analysis. On multivariate analysis, preoperative UTI and prolonged operative time were found to have a significant association with postoperative UTI.

CONCLUSION

The present study demonstrated that preoperative UTI and prolonged operative time are independent factors responsible for postoperative UTI. Large stone burden, stone multiplicity, and diabetes mellitus contribute to a higher risk for UTI following RIRS.

RIRS with FV-UAS vs. MPCNL for 2-3-cm upper urinary tract stones: a prospective study

To observe the efficacy and safety of retrograde intrarenal surgery (RIRS) combined with flexible vacuum-assisted ureteral access sheath (FV-UAS) and minimally invasive percutaneous nephrolithotomy (MPCNL) in patients with 2-3 cm upper urinary tract stones. A total of 160 patients with 2-3 cm upper urinary tract stones were prospectively randomized into 2 groups-80 in the FV-UAS group and 80 cases as control in the MPCNL group. The stone-free rates (SFRs) at different times (postoperative 1st day and 4th week) were considered as the primary outcome of the study. The secondary end points were operative time, hemoglobin decrease, postoperative hospital stay, and operation-related complications. There was no obvious difference between the two groups in patient's demographics and preoperative clinical characteristics (all P > 0.05). Postoperative data showed that mean decrease in hemoglobin level was less in FV-UAS group than that in MPCNL group (5.3 vs. 10.8 g/L, P < 0.001). Postoperative hospital stay in FV-UAS group was more shorten than that in MPCNL group (2.7 vs. 4.9 days, P < 0.001). There was no statistical significance between the two groups in SFRs during postoperative 1st day and 4th week (both P > 0.05). However, in terms of the rates of bleeding and pain, MPCNL group were both significantly higher than FV-UAS group (6.2 vs. 0.0%, P = 0.023; 16.2 vs. 2.5%, P = 0.003; respectively). Our study showed that RIRS with FV-UAS, a new partnership to treat 2-3 cm upper urinary tract stones, was satisfying as it achieved a high SFR rate and a low rate of complications. This method was safe and reproducible in clinical practice.

Prognostic and Diagnostic Power of Delta Neutrophil Index and Mean Platelet Component in Febrile Patients with Suspected Sepsis

BACKGROUND

The delta neutrophil index (DNI), a prognostic and diagnostic marker for sepsis, is based on the leukocyte count. Platelet activation, similar to leukocyte activation, plays a crucial role in host defense against pathogens and may serve as a predictor of sepsis outcome. However, the combined evaluation of mean platelet component (MPC) and DNI has rarely been used to assess sepsis.

METHODS

To assess the prognostic and diagnostic validity of the simultaneous evaluation of DNI and MPC in cases of human febrile sepsis, we conducted measurements of cellular indices, including DNI and MPC, as well as molecular biomarkers, including procalcitonin (PCT) and C-reactive protein (CRP). This study was carried out in patients admitted to the emergency department with suspected sepsis.

RESULTS

Using a cutoff value of 2.65%, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the DNI in sepsis were found to be 69%, 73.9%, 77.9%, and 64.1%, respectively. Furthermore, significant differences in DNI and MPC levels were observed between the sepsis and non-sepsis groups (6.7 ± 7.8% versus 2.1 ± 2.2% (p = 0.000) and 26.0 ± 1.9 g/dL versus 26.8 ± 1.4 g/dL (p = 0.002), respectively). Notably, there was a negative correlation between DNI and MPC, with the strength of the correlation varying based on the cause of sepsis. By setting the cutoff value of the DNI to 6.2%, its sensitivity, specificity, and NPV improved to 100%, 80.3%, and 100%, respectively, although the PPV remained at 10.6%.

CONCLUSIONS

In our study, the DNI demonstrates superior effectiveness compared with other molecular biomarkers, such as CRP and procalcitonin, in distinguishing septic febrile patients from non-septic febrile patients. Additionally, a negative correlation exists between MPC and DNI, making MPC a valuable marker for differentiating the etiology of sepsis. These findings hold significant clinical implications, as DNI/MPC evaluation is a cost-effective and readily applicable approach in various impending sepsis scenarios. Notably, this study represents the first examination of the prognostic and diagnostic validity of employing the simultaneous evaluation of DNI and MPC in human cases of febrile sepsis.

Does gender influence retrograde intrarenal surgery (RIRS) outcomes? Data from the Flexible Ureteroscopy Outcomes Registry (FLEXOR)

INTRODUCTION AND OBJECTIVES

As well established flexible ureteroscopy (RIRS). There is still no evidence if gender can have any influence on the outcomes and complication when performing. This study aims to evaluate the role that gender has in performing flexible ureteroscopy from a large series of patients.

METHODS

This study retrospectively analyzed patients who underwent RIRS for renal stones from January 2018 to August 2021 within the multicentric FLEXOR registry. Demographics, stone characteristics, perioperative findings, results and complications were analyzed and compared between gender groups.

RESULTS

A total of 6669 patients were included, 66.1% were male and 33.9% were female. Stone characteristics was comparable between groups. Female patients had significant higher fever and positive urine culture rates (12% vs. 8% and 37% vs. 34%). Also, females had a slight longer hospital stay (3.8 vs. 3.5 days; P < 0.001) and more residual fragments after the procedure (23.03% vs. 20.97 (P = 0.032). Overall complications were slightly significantly higher in women (15.74% vs. 14% (P = 0.042)) mainly at the expense of fever rates (6.9% vs. 5.7%) whereas the risk of sepsis was similar in both groups. A multivariate analysis showed that larger stone size, multiple and lower pole stones seem to have a negative impact in the incidence of residual stones and complications.

CONCLUSION

Our real life global study reflects that female gender may have a correlation with a slightly increased residual fragment rate and overall low grade complications. However, women can safely be treated with RIRS with no increased the rate of sepsis with appropriate care.

Comparative efficacy between retrograde intrarenal surgery with vacuum-assisted ureteral access sheath and minimally invasive percutaneous nephrolithotomy for 1-2 cm infectious upper ureteral stones: a prospective, randomized controlled study

Objective

To observe the efficacy and safety of retrograde intrarenal surgery combined with vacuum-assisted ureteral access sheath (V-UAS) and minimally invasive percutaneous nephrolithotomy (MPCNL) in patients with 1-2 cm infectious upper ureteral stone.

Patients and methods

A total of 173 patients with 1-2 cm infectious upper ureteral stone were prospectively randomized into two groups. Eighty-six in the V-UAS group and 87 cases as control in the MPCNL group. The SFRs at different times (Postoperative 1 day, 2nd week and 4th week) was considered as the primary outcome of the study. The secondary end points were operative time, postoperative hospital stay and operative complications.

Results

There was no obvious difference between two groups in patients' demographics and preoperative clinical characteristics (all P > 0.05). Postoperative data showed that the SFR at postoperative 1 day in the V-UAS group was significantly lower than that in the MPCNL group (73.2% vs. 86.2%, P = 0.034). However, there was no statistical significance between two groups in SFRs during postoperative 2 weeks and 4 weeks (All P > 0.05). The levels of WBC, CRP and PCT were all significant lower in the V-UAS group than those in the MPCNL group at the postoperative 24 h and 48 h (all P < 0.05). Postoperative complications included fever (≥38.5°C), bleeding, pain and urosepsis. In terms of the rates of fever, pain and urosepsis, MPCNL group were all significantly higher than those in the V-UAS group (10.3 vs. 2.4%, P = 0.031; 14.9 vs. 2.4%, P = 0.003; 4.6 vs. 0.0%, P = 0.044; respectively). No significant difference was found between two groups in bleeding. Meanwhile, postoperative hospital stay in the V-UAS group was more shorten than that in the MPCNL group (3.7 vs. 5.9 days, P < 0.001).

Conclusions

Our study showed that RIRS with V-UAS, a new partnership to treat 1-2 cm infectious upper ureteral stones, was satisfying as it achieved a high SFR rate and a low rate of infectious complications. This method was safe and reproducible in clinical practice.

Analysis of the effect of holmium laser flexible ureteroscopic intrapelvic drainage in the treatment of parapelvic renal cysts

Objective

To explore the efficacy, safety, and feasibility of holmium laser flexible ureteroscopic intrapelvic drainage in the treatment of parapelvic renal cysts.

Methods

From September 2012 to February 2019, a total of 18 patients, aged from 28 to 62 (mean±standard deviation [SD]: 46.50±9.14) years, were diagnosed with parapelvic renal cysts and treated by holmium laser flexible ureteroscopic intrapelvic drainage. There were 10 males and eight females. All of the parapelvic renal cysts were unilateral, and two cases were complicated with pyelolithiasis. The diameters of the cysts ranged from 4.1 cm to 8.2 cm.

Results

All the patients completed the operation successfully in one stage without conversion to open surgery; in two cases, it was difficult to find the cysts during the operation, and the localization was completed by B-ultrasound and percutaneous injection of methylene blue. The mean operative time was 33.89 (SD: 9.68; range: 22-54) min, and the mean hospitalization time was 2.67 (SD: 0.91; range: 2-5) days. Three months and 6 months of follow-up were performed after surgery. The cysts disappeared in 13 (72%) cases, and the diameter of the cysts in five (28%) cases decreased by more than 50%.

Conclusion

Holmium laser flexible ureteroscopic intrapelvic drainage in the treatment of parapelvic renal cysts is simple, safe, and effective, and can be used as the first choice for the treatment of parapelvic renal cysts.

European Association of Urology Section of Urolithiasis and International Alliance of Urolithiasis Joint Consensus on Retrograde Intrarenal Surgery for the Management of Renal Stones

BACKGROUND

Retrograde intrarenal surgery (RIRS) has become the preferred treatment modality for nephrolithiasis. However, because of ongoing uncertainties regarding the optimal perioperative management, operative technique, and postoperative follow-up, as well as a lack of standardization for outcome reporting, consensus is needed to achieve more uniform clinical practice worldwide.

OBJECTIVE

To develop recommendations for RIRS on the basis of existing data and expert consensus.

DESIGN, SETTING, AND PARTICIPANTS

A protocol-driven, three-phase study was conducted by the European Association of Urology Section of Urolithiasis (EULIS) and the International Alliance of Urolithiasis (IAU). The process included: (1) a nonsystematic review of the literature to define domains for discussion; (2) a two-round modified Delphi survey involving experts in this field; and (3) an additional group meeting and third-round survey involving 64 senior representative members to formulate the final conclusions.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The results from each previous round were returned to the participants for re-evaluation of their decisions during the next round. The agreement threshold was set at 70%.

RESULTS AND LIMITATIONS

The panel included 209 participants who developed 29 consensus statements on the following topics of interest: (1) perioperative infection management; (2) perioperative antithrombotic therapy; (3) fundamentals of the operative technique; and (4) standardized outcome reporting. Although this consensus can be considered as a useful reference for more clinically oriented daily practice, we also acknowledge that a higher level of evidence from further clinical trials is needed.

CONCLUSIONS

The consensus statements aim to guide and standardize clinical practice and research on RIRS and to recommend standardized outcome reporting.

PATIENT SUMMARY

An international consensus on the best practice for minimally invasive surgery for kidney stones was organized and developed by two international societies. It is anticipated that this consensus will provide further guidance to urologists and may help to improve clinical outcomes for patients.

Infectious complications of endourological treatment of kidney stones: A meta-analysis of randomized clinical trials

OBJECTIVE

Endourological treatment is associated with a risk of postoperative febrile urinary tract infections and sepsis. The aim of this study was to review the reported rate of infectious complications in relation to the type and modality of the endourologic procedure.

METHODS

This systematic review was conducted in accordance with the PRISMA guidelines. Two electronic databases (PubMed and EMBASE) were searched. Out of 243 articles retrieved we included 49 studies after full-text evaluation.

RESULTS

Random-effects meta-analysis demonstrated that retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) were associated with not significantly different odds of getting fever (OR = 1.54, 95% CI: 0.99 to 2.39; p = 0.06) or sepsis (OR = 1.52, 95% CI: 0.37 to 6.20, p = 0.56). The odds of getting fever were not significantly different for mini PCNL compared to standard PCNL (OR = 1.11, 95% CI: 0.85 to 1.44; p = 0.45) and for tubeless PCNL compared to standard PCNL (OR = 1.34 95% CI: 0.61 to 2.91, p = 0.47). However, the odds for fever after PCNL with suctioning sheath were lower than the corresponding odds for standard PCNL (OR = 0.37, 95% CI: 0.20 to 0.70, p = 0.002). The odds of getting fever after PCNL with perioperative prophylaxis were not different from the corresponding odds after PCNL with perioperative prophylaxis plus a short oral antibiotic course (before or after the procedure) (OR = 1.31, 95% CI: 0.71 to 2.39, p = 0.38).

CONCLUSIONS

The type of endourological procedure does not appear to be decisive in the onset of infectious complications, although the prevention of high intrarenal pressure during the procedure could be crucial in defining the risk of infectious complications.   on behalf of U-merge Ltd. (Urology for emerging countries), London-Athens-Dubai.

Can We Identify Patients in Danger of Complications in Retrograde Intrarenal Surgery?-A Retrospective Risk Factors Analysis

Retrograde intrarenal surgery (RIRS) is an innovative and effective method of kidney stones treatment, as it had great influence on the development of endoscopy in urology. The increasing prevalence of urolithiasis together with the rapid development of endourology leads to a rise in the number of procedures related to the disease. Flexible ureteroscopy is constantly being improved, especially regarding the effectiveness and safety of the procedure. The purpose of this study is to evaluate intraoperative and early post-operative complications of RIRS in the treatment of kidney stones. A retrospective analysis of medical records was performed. A series was comprised of 207 consecutive operations performed from 2017 to 2020. Complications occurred in 19.3% (n = 40) of patients. Occurrence according to the Clavien-Dindo scale was: 11.1% for grade I, 5.8% for grade II and 2.4% for grade IV. Infectious complications included SIRS (5.3%, n = 11) and sepsis (2.4%, n = 5). Statistical analysis revealed a correlation between acute post-operative infections and positive midstream urine culture, history of chronic or recurrent urinary tract infections, and increased body mass index (BMI). Furthermore, a significant correlation was observed between pain requiring the use of opioids with BMI over 25. Consequently, history of urinary tract infections, positive pre-operative urine culture, and increased BMI are considered risk factors and require appropriate management.

Retrograde intrarenal surgery is a safe procedure in severe obese patients. Is it reality or prediction? A propensity score-matching analysis from RIRSearch study group

OBJECTIVE

The aim of the study was to assess whether severely obese patients have an increased risk of complications during and after retrograde intrarenal surgery.

MATERIALS AND METHODS

The data of 639 consecutive patients undergoing retrograde intrarenal surgery for the treatment of upper tract urinary stones were analyzed retrospectively. The patients were divided into two groups according to their body mass index numbers (Group 1, <35; Group 2, ≥35). The patients' demographics, stone characteristics, operative outcomes, and complication rates were compared between the groups. The primary objective was to examine whether the intraoperative and postoperative complication rates were higher in patients with a body mass index of ≥35 kg/m2.

RESULTS

After matching of confounding factors, Group 1 comprised 135 patients, and Group 2 comprised 47 patients. The baseline characteristics were similar between the groups. There were no significant differences between groups for intraoperative complication rates (11.8% and 12.8%, respectively; p=0.97). There was statistically significant difference in favor of Group 2 for postoperative complication rates (12.6% and 29.7%; respectively, p<0.01), overall complication rates (22.9% and 38.2%; respectively, p=0.02), mean operation time (56.15 minute vs 66.45 minute; respectively, p= 0.01) and length of stay (1.4 days vs 2.1 days; p=0.03). Stone free rates (75.5% vs 85.1%; respectively, p=0.17) did not differ between groups.

CONCLUSIONS

Retrograde intrarenal surgery is an efficient and feasible treatment option for upper urinary tract stones in severe obese patients. However, higher possibility of postoperative, especially infectious, complication rates should be taken into account in these patients.

Perirenal Extravasation After Retrograde Intrarenal Surgery for Renal Stones: A Prospective Study

Background

The incidence and consequences of the perirenal extravasation of the irrigation fluid during retrograde intrarenal surgery (RIRS) are not fully elucidated. The objective of this study was to assess the incidence, risk factors, and complications of perirenal extravasation of irrigation fluid during RIRS.

Methods

This prospective observational study was conducted in the Department of Urology, Bir Hospital, Kathmandu, Nepal, from January 2020 to March 2021. Patients undergoing RIRS for renal stones less than 2 cm in diameter were included in the study. Irrigation during the procedure was performed using isotonic normal saline under gravity at 50 cm from the symphysis pubis of patients with intermittent manual compression if required. Lithotripsy was performed with 120-Watt Ho:YAG laser using 200-micron laser fiber. Retrograde pyelogram was performed after the completion of lithotripsy to document the presence or absence of extravasation on fluoroscopic images. A double-J stent was placed at the end in all patients. Patients were observed for systemic inflammatory response syndrome (SIRS) features. Postoperative abdominal ultrasonography was performed on the first postoperative day to assess the perirenal collection together with complete blood count. The visual analogue scale (VAS) was used to assess pain in postoperative period. The preoperative patient’s and stone characteristics, hydronephrosis, intraoperative characteristics, and postoperative findings were analyzed.

Results

A total of 71 patients who underwent RIRS during the study period were analyzed. The mean (SD) stone size was 13.19 (3.12) mm. Intraoperative perirenal extravasation of contrast was noted in eight (11.26%) patients; however, no patient had ipsilateral perirenal collection on ultrasonography obtained on the first postoperative day. No significant differences were observed among patients with or without perirenal extravasation in terms of mean stone size, laser settings, operative duration, and lasing duration. Use of ureteral access sheath (UAS) was associated with lower incidence of extravasation; however, it was not significant. SIRS was documented in eight patients overall, with none of the patients with extravasation having features of SIRS. Patients with extravasation experienced more postoperative flank pain (p<0.05).

Conclusion

Perirenal extravasation was common during RIRS and was associated with higher postoperative pain scores. Stone size, use of UAS, laser settings, operative duration, and lasing duration were not associated with an increased risk of extravasation. Extravasation was not associated with increased postoperative complications.

Should ureteroscopy be performed for patients after ureteral reconstruction with autologous onlay flap/graft?

Background

To analyze the safety and clinical significance of performing ureteroscopy after ureteral reconstruction with autologous onlay/graft. To describe the ureteroscopic appearances of the appendiceal onlay flap and lingual mucosa graft.

Methods

Beginning in August 2018, we conducted a prospective cohort study of autologous onlay/graft techniques to repair ureteral strictures. The perioperative data of 42 patients who had undergone surgery more than 6 months prior were collected prospectively. During the postoperative follow-up, ureteroscopy was performed in 27 patients (64.3%) after surgery (group A), and ureteroscopy was not performed in the other 15 patients (35.7%) (group B). We carried out a comparative study of these two groups of patients. Analyses were conducted mainly on complications related to ureteroscopy and the success rate of ureteral reconstruction surgery.

Results

There were no significant differences in patient demographic data or the length of ureteral reconstruction between the two groups (P>0.05). For the ureteroscopy group, the median time from repair surgery to ureteroscopy was 3 (range, 2-7) months, there was no poor healing of the anastomosis, and the ureteral lumen of all patients was unobstructed. Some expected observations can be found in the ureteral lumen, such as mucosa edema, stones, follicles and granulation tissue. Among the 27 patients, one patient (3.7%) developed bleeding intraoperatively and 7 patients (25.9%) were found to have low-grade (Clavien-Dindo I and II) postoperative complications, including 5 cases of fever and 2 cases of bleeding. The mean follow-up times of patients in group A and group B were 16.7±6.4 and 19.0±10.1 months, respectively. The objective success (imaging showed hydronephrosis ease) rate of the two groups was 100%. The subjective success (symptom relief) rates of group A and group B were 96.3% and 100%, respectively.

Conclusions

Patients after autologous onlay flap/graft ureteroplasty do not need to undergo routine ureteroscopy unless there is aggravation of hydronephrosis or other indications for ureteroscopy, such as stones.

Risk factors for infectious complications after retrograde intrarenal surgery - a systematic review and narrative synthesis

Introduction

Infectious complications are among the most frequent and significant complications in retrograde intrarenal lithotripsy. To date, review articles have covered complications after a ureteroscopy, but not after retrograde intrarenal surgery (RIRS), specifically. Because the complications and risk factors are different for a ureteroscopy and RIRS, we aimed to identify variables related to the occurrence of infectious complications post-RIRS.

Material and methods

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. We included original studies that described 100 or more procedures published in 2014–2021. We extracted data and performed a narrative synthesis to explore and interpret differences between the studies.

Results

We selected 17 studies for analysis, including 10 from 2019–2021. Infectious complications after RIRS were observed in 2.8–7.5% of patients (mean 7.1%). We found seven independent risk factors associated with infectious complications after RIRS: long operative time, recent history of positive urine culture or urinary tract infection or antibiotic use, pyuria/nitrites, small caliber of ureteral access sheath, struvite stone, high irrigation rate, and comorbidities.

Conclusions

If an increased rate of infectious complications is found at a RIRS center, countermeasures should include restrictions on operative time and irrigation rate, and consideration of larger access sheaths, especially for patients with abnormal urine results or with struvite stones or with a history of urinary tract infection or co-morbidities.

The effect of perirenal fat stranding on infectious complications after ureterorenoscopy in patients with ureteral calculi

Objective

Perirenal fat stranding (PFS) is linear areas of soft-tissue attenuation in the perirenal space on non-contrast computed tomography. The present study aimed to investigate whether PFS is associated with infectious complications after ureterorenoscopy (URS) in patients with ureteral calculi in any location.

Methods

The data of 602 patients with ureteral stones who underwent URS were analyzed retrospectively. The patients were divided into two groups as Group 1 (PFS not detected) and Group 2 (PFS detected). Gender, and age of patients, size, side, and location of the stone, operation time, double-J stent insertion status, perioperative ureter injury, postoperative infection after URS and related complications, and duration of hospital stay were compared.

Results

While PFS was not detected in 530 patients, PFS was detected in 72 patients. The mean age, male/female ratio, side and localization of the stones, operation time, and perioperative insertion of the double-J after lithotripsy were statistically similar (p>0.05). The median stone diameter was smaller in Group 2 (9 mm vs. 8 mm) (p=0.033). Fever was observed in 30 and 38 patients in Group 1 and Group 2, respectively (p=0.0001). Urinary tract infection was detected in 24 and 27 patients in Group 1 and Group 2, respectively (p=0.0001). The urosepsis did not occur in any patients in Group 1, whereas 8 (11.1%) patients in Group 2 experienced urosepsis (p=0.0001).

Conclusion

According to the results of the present study, patients with ureteral stones accompanied by PFS are much more prone to ureteral injuries and infectious complications such as urinary tract infection, fever, and sepsis after URS.

Ureteral access sheath-related injuries vs. post-operative infections. Is sheath insertion always needed? A prospective randomized study to understand the lights and shadows of this practice

OBJECTIVE

To compare intraoperative ureteral injuries in RIRS with UAS insertion with the rate of postoperative infections after RIRS without UAS insertion.

PATIENTS AND METHODS

In this randomized trial, patients who received an indication for RIRS between January 2017 and December 2017 were divided into two groups. Group A had no UAS insertion and Group B had UAS insertion. Post-Ureteroscopic Lesion Scale (PULS) grading was performed after UAS or flexible ureteroscope removal. Proximal, middle and distal ureteral lesions were evaluated and compared according to the PULS scale. Additionally, patients in both groups were followed postoperatively to assess any infective complication.

RESULTS

The evaluation comprised 181 patients, 89 for group A and 92 for group B. Overall stone-free rate, clinically insignificant residual fragments, and final stone-free rate were 41.4%, 53.5%, and 95%, respectively. There were 33 (37.1%) patients with ureteral lesions in group A while 42 (45.6%) patients had ureteral lesions in group B, with no significant difference. On the other hand, the overall presence of postoperative infection rate was much higher for Group A (37.1% vs 16.3% P = 0.03).

CONCLUSIONS

UAS insertion does not result in a higher number of ureteral injuries. UAS insertion during RIRS allows a lower rate of postoperative infections.

CLINICAL TRIAL REGISTRATION NUMBER (ISRCTN REGISTRY NUMBER)

55546280.

Comparison of the Efficacy of ShuoTong Ureteroscopy and Simple Flexible Ureteroscopy in the Treatment of Unilateral Upper Ureteral Calculi

Background: ShuoTong ureteroscopy (Sotn-ureteroscopy, ST-URS), a new lithotripsy operation method developed on the basis of ureteroscopy, is widely used to treat ureteral stones in China. Its composition includes rigid ureteral access sheath, standard mirror, lithotripsy mirror, and ShuoTong perfusion aspirator (ST-APM). Here, we compared the efficacy and safety of the ST-URS and the flexible ureteroscope (F-URS) holmium laser lithotripsy in the treatment of unilateral upper ureteral calculi. Methods: Retrospective analysis was conducted on the clinical data of 280 patients who met the inclusion 1) urinary tract CT was diagnosed with unilateral single upper ureteral calculi above the L4 lumbar spine; 2) patient age was from 18 to 80 years old; 3) patients were informed and consented to this study; and 4) patients were approved by the hospital ethics committee (proof number: KY-2019-020) and the exclusion criteria for unilateral upper ureteral calculi in the First Affiliated Hospital of Xiamen University from January 2018 to November 2020, and they were divided into the ST-URS group and the flexible ureteroscopy (F-URS) group. Results: The stone-free rate of 1 day after operation of the ST-URS group was significantly higher than the F-URS group (63.71 vs. 34.62%, P < 0.0001). The operative time (38.45 vs. 46.18 min, P = 0.005) and hospitalization cost (27,203 vs. 33,220 Yuan, P < 0.0001) of the ST-URS group were significantly lower than the F-URS group. There were no significant differences in the success rate of ureteral access sheath placement, operative blood loss, stone-free rate of 1 month after operation, postoperative complications, postoperative hospital stay, and postoperative visual analog scale (VAS) pain score between the two groups (P > 0.05). In subgroups of a diameter of calculi ≥ 1.5 cm, calculi CT numerical value ≥ 1,000 Hounsfield unit and the preoperative hydronephrosis range ≥ 3.0 cm, ST-URS shows more advantages in the operative time, stone-free rate of 1 day after the operation, the hospitalization cost, and the incidence of postoperative complications. Conclusion: In unilateral upper ureteral stones treated with a holmium laser, compared with the simple F-URS, the ST-URS has a shorter operative time, lower hospitalization cost, and a higher stone-free rate of 1 day after the operation, suggesting that the ST-URS could be more widely applied in clinics.

Low Body Mass Index as a Predictive Factor for Postoperative Infectious Complications after Ureterorenoscopic Lithotripsy

Background and Objectives: In this study, we aimed to evaluate predictive factors of postoperative fever (POF) after ureterorenoscopic lithotripsy (URSL). Materials and Methods: A total of 594 consecutive patients who underwent URSL for urinary stone disease at Gifu Municipal Hospital and Chuno Kosei Hospital between April 2016 and January 2021 were enrolled in this study. In all patients, antibiotics were routinely administered intraoperatively and the next day after surgery. We used rigid and/or flexible ureterorenoscopes depending on the stone location for URSL. Stones were fragmented using a holmium: YAG laser. The fragments of the stone were manually removed as much as possible using a stone basket catheter. A ureteral stent was placed at the end of the surgery in all cases. Results: The median age and body mass index (BMI) in all patients were 62 years and 23.8 kg/m², respectively. The median operation duration was 52 min. The most common URSL-related complication was POF in 28 (4.7%) patients. In these patients, the rates of antibiotic administration and ureteral stent insertion before surgery were significantly higher than in those without POF. In multivariate analysis, BMI was associated with POF after URSL. There were no significant differences in predicting POF after surgery in patients who had bacteriuria or received antibiotics before surgery. Conclusions: A low BMI was significantly associated with POF after URS or URSL.

Ureteral access sheath-related injuries vs. post-operative infections. Is sheath insertion always needed? A prospective randomized study to understand the lights and shadows of this practice

OBJECTIVE

To compare intraoperative ureteral injuries in RIRS with UAS insertion with the rate of postoperative infections after RIRS without UAS insertion.

PATIENTS AND METHODS

In this randomized trial, patients who received an indication for RIRS between January 2017 and December 2017 were divided into two groups. Group A had no UAS insertion and Group B had UAS insertion. Post-Ureteroscopic Lesion Scale (PULS) grading was performed after UAS or flexible ureteroscope removal. Proximal, middle and distal ureteral lesions were evaluated and compared according to the PULS scale. Additionally, patients in both groups were followed postoperatively to assess any infective complication.

RESULTS

The evaluation comprised 181 patients, 89 for group A and 92 for group B. Overall stone-free rate, clinically insignificant residual fragments, and final stone-free rate were 41.4%, 53.5%, and 95%, respectively. There were 33 (37.1%) patients with ureteral lesions in group A while 42 (45.6%) patients had ureteral lesions in group B, with no significant difference. On the other hand, the overall presence of postoperative infection rate was much higher for Group A (37.1% vs 16.3% P=.03).

CONCLUSIONS

UAS insertion does not result in a higher number of ureteral injuries. UAS insertion during RIRS allows a lower rate of postoperative infections. Clinical Trial Registration Number (ISRCTN registry number): 55546280.

Retrospective analysis of the factors affecting intraoperative and immediate postoperative complications of RIRS classified by the Clavien and Satava grading systems

BACKGROUND

To classify intraoperative and postoperative complications using the modified Clavien classification system(MCCS) and modified Satava classification system(SCS) and to evaluate the parameters associated with complications in patients undergoing retrograde intrarenal surgery(RIRS) for renal and proximal ureteral stones.

MATERIALS AND METHODS

We performed a retrospective analysis of 949 patients who underwent RIRS for renal stones and proximal ureteral stones at two institutions between March 2015 and June 2020. Intraoperative complications were assessed using SCS and postoperative complications were graded according to MCCS. Univariate and multivariate analyses were undertaken to determine predictive factors affecting complication rates.

RESULTS

The median stone size was determined as 13 mm (range 10-20 mm). The stone-free rate was 83.6% after the first intervention. Reprocedure was applied to 89 of the patients with residual stones and the final stone-free rate was 94.4% after reprocedure. According to SCS, the number of intraoperative events and complication incidences was 153(16.1%). MCCS revealed postoperative complications in 121(12.8%) patients. Major complications were observed in 18(1.9%) patients. The rate of complications was higher in patients with renal anomalies (9.9% vs 3.4%, p=0.001). Stone location, stone size, stone burden, stone number, stone density and residual fragments were determined to be associated with the development of complications (p<0.001,p<0.001,p<0.001, p<0.001,p=0.002 and p<0.001 respectively). In addition, the multivariate analysis revealed that only presence of residual fragments was a significant predictor of complication development for the patients with Grade≥3 complications according to MCCS (p=0.032). However, significant predictors were stone burden (p<0.001), stone density (p=0.002) and fluoroscopy time (p<0.001) for those with Grade≥2b complications according to SCS.

CONCLUSION

This study showed that abnormal kidney anatomy, operation time, stone burden and residual fragments were reliable predictors of complication development during and after RIRS. Appropriate preoperative management should be planned according to these predictors to prevent intraoperative and postoperative complications.

Introducing 3D printed models of the upper urinary tract for high-fidelity simulation of retrograde intrarenal surgery

PURPOSE

Training in retrograde intrarenal surgery for the treatment of renal stone disease is a challenging task due to the unique complexity of the procedure. This study introduces a series of 3D printed models of upper urinary tract and stones designed to improve the training process.

METHODS

Six different models of upper urinary tract were algorithmically isolated, digitally optimized and 3D printed from real-life cases. Soft and hard stones in different sizes were produced from 3D printed moulds. The models were fitted onto a commercially available part-task trainer and tested for retrograde intrarenal surgery.

RESULTS

Each step of the procedure was simulated with extraordinary resemblance to real-life cases. The unique anatomical intricacy of each model and type of stones allowed us to reproduce surgeries of increasing difficulty. As the case-load required to achieve proficiency in retrograde intrarenal surgery is high, benchtop simulation could be integrated in training programs to reach good outcomes and low complication rates faster. Our models match incredible anatomical resemblance with low production cost and high reusability. Validation studies and objective skills assessment during simulations would allow comparison with other available benchtop trainers and the design of stepwise training programs.

CONCLUSIONS

3D printing is gaining a significant importance in surgical training. Our 3D printed models of the upper urinary tract might represent a risk-free training option to hasten the achievement of proficiency in endourology.

Risk factors of febrile urinary tract infections following retrograde intrarenal surgery for renal stones

We aimed to evaluate the risk factors of febrile urinary tract infection (UTI) following retrograde intrarenal surgery (RIRS) for treating renal stones.We retrospectively reviewed the data of patients with 10 - 30 mm kidney stones who underwent RIRS from January 2014 to July 2017. Evaluation included age, gender, body mass index, stone size, stone location, and operative time. All surgeries were performed by a single surgeon and ureteral stenting was not done prior surgery. The risk factors of febrile UTI after RIRS were assessed by univariate and multivariate logistic regression analysis.A total of 150 patients were included in the present study, and 17 patients (11.3%) had febrile UTI after RIRS. Mean patient age was 56.64 ± 13.91 years, and both genders were evenly distributed. Mean stone size was 14.16 ± 5.89 mm. and mean operation time was 74.50 ± 42.56 minutes. According to univariate analysis, preoperative pyuria was associated with postoperative febrile UTI. Multivariate logistic regression analysis showed that preoperative pyuria was the only independent risk factor of infectious complications after RIRS (odds ratios 8.311, 95% confidence intervals 1.759 - 39.275, P = .008). Age, gender, body mass index, comorbidity, preoperative bacteriuria, presence of hydronephrosis, renal stone characteristics, and operative time were not associated with febrile UTI after RIRS.Preoperative pyuria was the only risk factor of infectious complications following RIRS. Therefore, careful management after RIRS is necessary especially when preoperative urinalysis shows pyuria.

A cut-off value for the operation time and other risk factors in terms of the infection risk for flexible ureterorenoscopy

OBJECTIVES

To investigate the operation time (OT) and ureteral access sheath (UAS) usage with the infection rates and to determine a cut-off value for OT.

METHODS

We retrospectively analysed the data of the patients who underwent flexible ureterorenoscopy (FURS) for renal stones larger than 20 mm between 2010 and 2019. The investigated parameters were OT, UAS using, and infection status. The data were analysed by forming two groups according to whether the OT was less than 60 minutes and more, whether the UAS was used and whether an infection occurred. In addition, independent risk factors that may affect postoperative urinary infection development were also investigated by logistic regression analysis. And, a Receiver Operating Characteristic (ROC) curve analysis was applied to determine a cut-off value in OT terms, where infection rates increase more.

RESULTS

A total of 575 patients were enrolled in the study. The rates of the usage of UAS and infection were greater statistically in the group for longer than 60 minutes. OT was longer statistically in the infection group than in the group without infection (94.1 ± 14.2 and 68.01 ± 23.1, for groups 1 and 2, respectively, P < .05, Table 2). OT was statistically longer in the UAS group than the unused one (79.3 ± 24.4 and 66.7 ± 22.4, for groups 1 and 2, respectively, P < .05, Table 3). ROC analyses revealed a cut-off point of 87.5 min for OT in terms of infection rate.

CONCLUSION

While the infection risk increases when OT exceeds 60 minutes, FURS can be safely performed up to 87.5 minutes with 89% sensitivity and 69% specificity infection risk.

Disposable versus Reusable Ureteroscopes: A Prospective Multicenter Randomized Comparison

Purpose

To compare reusable and disposable flexible ureteroscopes in terms of efficacy and safety for patients undergoing Retrograde Intrarenal Surgery (RIRS).

Patients and Methods

Patients with a renal stone eligible for RIRS were enrolled in this multicenter, randomized, clinical trial study. Patients were randomized into two groups: group A (90 patients) underwent RIRS with a reusable flexible ureteroscope and group B (90 patients) were treated with a disposable one.

Results

The patients’ demographics, stone features and pre-operative urine cultures were comparable between the groups. The Stone Free Rates (SFRs) were not significantly different (86.6% and 90.0% for group A and group B, respectively, p=0.11) and the mean cost for each procedure was comparable (2321 € in group A vs 2543 € in group B, p=0.09). However, the days of hospitalization and of antibiotic therapy were higher in group A (p ≤ 0.05). The overall complication rate in group A was 8.8% whilst in group B it was 3.3% (p ≤ 0.05); in particular, group A exhibited a greater number of major complications (Clavien score IIIa-V). The overall postoperative infection rate was 16.6% in group A and 3.3% in group B (p ≤ 0.05). Furthermore, none of the patients in group B developed urosepsis or had a positive blood culture, while 3 patients in group A did (p<0.05).

Conclusion

The use of disposable ureteroscopes is characterized by significantly lower post-operative complications and infection rates, while having comparable costs and SFRs vis à vis reusable ureteroscopes. Clinical Trial Registration Number: ISRCTN92289221.

Effectiveness of Flexible Ureterorenoscopy Versus Extracorporeal Shock Wave Lithotripsy for Renal Calculi of 5-15 mm: Results of a Randomized Controlled Trial

Background

Primary flexible ureterorenoscopy (URS) and extracorporeal shock wave lithotripsy (SWL) are treatment options in patients with renal calculi of 5-15 mm.

Objective

To compare effectiveness, complication rates, and pain scores between primary URS and SWL.

Design setting and participants

Between 2011 and 2016, patients with renal calculi between 5 and 15 mm were randomized to undergo either primary URS or SWL.

Outcome measurements and statistical analysis

Stone-free rate and size of residual fragments assessed by computed tomography after 3 mo, complications, and pain scores were evaluated.

Results and limitations

The study was prematurely closed after randomizing 44 patients due to poor accrual. The 3-mo stone-free rate and mean residual stone size were, respectively, 61% and 1.8 mm after URS and 48% and 2.4 mm after SWL. Early post-treatment pain scores were significantly higher after URS than after SWL on day 1 (3.3 vs 1.6, p =  0.02) and day 7 (5.2 vs 3.4, p =  0.04), but were no longer detectable after 3 wk and 3 mo, respectively. One Clavien-Dindo grade II complication was observed after URS (5%) and SWL (4%), while one (4%) grade IIIb complication was observed after SWL.

Conclusions

URS appears to be associated with higher early post-treatment discomfort, which could be associated with routine postoperative stenting. Owing to premature closure of this trial, the power was insufficient to formally compare URS and SWL; however, the present data might be informative to counsel patients about treatment outcomes and allow future meta-analyses.

Patient summary

This study was ended prematurely, but it contributes data about efficacy and side effects of different treatment options in patients with renal calculi.

The retrospective study of perioperative application of dexamethasone and furosemide for postoperative anti-inflammation in patients undergoing percutaneous nephrolithotomy

Objectives

To investigate whether the perioperatively combined application of dexamethasone and furosemide could alleviate the inflammation in patients undergoing percutaneous nephrolithotomy (PCNL).

Patients and methods

147 patients undergoing PCNL between November 2018 and October 2019 were enrolled in the study. 77 patients accepted a single dose of dexamethasone and furosemide administration (EXP group, n = 77), and 70 patients did not (CON group, n = 70). Demographic and perioperative data, inflammatory markers including interleukin-6 (IL-6) and procalcitonin (PCT), and clinical outcomes were compared between the two groups.

Results

Compared with the CON group, the incidence rate of urosepsis of the EXP group were significantly lower (11.69% vs. 24.29%, p = 0.046). 3 patients developed severe urosepsis in the EXP group, while 5 patients developed severe urosepsis in the CON group. Compared with those in the CON group, the patients with postoperative urosepsis in the EXP group showed lower serum levels of IL-6 at postoperative hour two (p = 0.045) and at postoperative day one (p = 0.031) and lower serum levels of PCT at postoperative day one (p = 0.015). There was a better clinical outcome of a shorter postoperative hospital stay (p = 0.015) in patients with postoperative urosepsis in the EXP group than in those in the CON group.

Conclusion

The perioperatively combined application of dexamethasone and furosemide was beneficial for alleviating postoperative inflammatory reaction and caused a better clinical outcome of a shorter postoperative hospital stay.

Feasibility and relevance of urine culture during stone fragmentation in patients undergoing percutaneous nephrolithotomy and retrograde intrarenal surgery: a prospective study

PURPOSE

We evaluated if, during lithotripsy, bacteria may be detected in the irrigation fluid of percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS). The concordance between urine culture from stone fragmentation (SFUC), bladder (BUC), renal pelvic (RPUC) and stone (SC) was analyzed. We also assessed the correlation between variables and cultures and their association with systemic inflammatory response syndrome (SIRS) and of a positive SC.

METHODS

We included 107 patients who underwent PCNL (n = 53) and RIRS (n = 54) from January 2017 to May 2018. Samples for RPUC were obtained by renal catheterization. Stone fragments and irrigation fluid sample were sent for culture.

RESULTS

SFUC was positive in 17 (15.9%), BUC in 22 (20.6%), RPUC in 26 (24.3%) and SC in 30 patients (28%). The concordance between SFUC and SC was the highest among all cultures: 94.1%. SFUC and SC grew identical microorganisms in 15/17 (88.2%) patients. Out of 17 (15.9%) patients with SIRS, 8 (7.5%) had sepsis. SFUC had the highest PPV and specificity to detect positive SC and SIRS. Previous urinary tract infection, a preoperative nephrostomy, stone diameter and composition, staghorn calculi, PCNL, positive BUC, RPUC and SFUC were predictors of infected stone. Variables that indicate complex stones, complex PCNL and an infection of the upper tract were associated with SIRS.

CONCLUSION

SFUC is technically feasible, easy to retrieve and to analyze. The spectrum of SFUC potential application in clinical practice is when is not possible to perform a SC, e.g. complete dusting or during micro-PCNL.

The preliminary experience of methylene blue assisted laparoscopy in the treatment of renal parapelvic cysts

Renal cyst is a common disease in humans and laparoscopic renal cyst decortication is the gold standard for treatment. However, specialized surgical skills are required for the treatment of renal parapelvic cysts. In this study, we describe an improved laparoscopic method for the treatment of renal parapelvic cysts involving the use of continuous infusion of methylene blue. Sixteen patients with renal parapelvic cyst were enrolled in this study. All patients underwent retrograde ureteral catheterization, with continuous perfusion of the renal pelvis using a solution of 0.2% methylene blue and saline, during laparoscopic decortication of the parapelvic cyst. In one patient, the cyst communicated with the renal collection system which was injured, but this was immediately repaired intraoperatively. All operations were successful, and none was converted to open surgery. There were no occurrences of persistent urinary fistula, bleeding, or other complications postoperatively. All patients were followed-up for 3-24 months, and results of postoperative imaging investigations revealed that all of our patients experienced either complete recovery or a greater than 50% decrease in size of the cysts. Our study demonstrates that methylene blue-assisted laparoscopic treatment is a safe, effective and practical method for the treatment of renal parapelvic cysts.

WITHDRAWN: Analysis on the diagnosis of infection risk factors and the incidence of ureteroscopy holmium laser lithotripsy and vagal excitation under computed tomography image information health technology

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Is plasma sterilization the modality of choice of sterilization today for endourological procedures such as ureterorenoscopy and retrograde intrarenal surgery? A single-center retrospective evaluation of 198 patients

Introduction:

The prevalence of infective complications among patients undergoing Retrograde Intrarenal Surgery (RIRS) for renal stone is 1.7%-18%, including fever, Systemic Inflammatory Response Syndrome (SIRS) and sepsis. The infectious complications of RIRS can be minimised by strict aseptic precautions and plasma sterilization. The Sterrad Next Generation (Sterrad NX) System, a low-temperature sterilizer represents the next generation of low-temperature hydrogen peroxide gas plasma sterilizers. This study was conducted to evaluate the efficacy of plasma sterilization among patients undergoing ureterorenoscopy (URS) and RIRS. The primary endpoint of this study was incidence of septicemia or related complications. Till date, there is no study on the incidence of infection rate in RIRS in relation to a specific mode of sterilization.

Material and Methods:

This is a retrospective study comprising of 198 patients undergoing URS and/or RIRS. The parameters studied were incidence of post-operative fever, Systemic Inflammatory Response Syndrome (SIRS), pyelonephritis or septicemic shock.

Results:

Out of 198 patients, incidence of post-operative fever was 3.5%, SIRS was 1.7%, pyelonephritis was 0.7% and septicemic shock was 0%. This is statistically significantly low septicemia rate among patients undergoing URS and /or RIRS as compared to the available literature. No health hazards of plasma sterilization were noted. No damage to the endoscopes or instruments was noted.

Conclusion:

Sterrad NX based on hydrogen peroxide gas plasma (HPGP) technology is highly efficacious, safe and the modality for sterilization of instruments, including heat labile instruments such as semi rigid, flexible and chip on the tip endoscopes and other EndoUrology armamentarium.

RIRS with Vacuum-Assisted Ureteral Access Sheath versus MPCNL for the Treatment of 2-4 cm Renal Stone

OBJECTIVE

Comparison of outcomes between RIRS with vacuum-assisted ureteral access sheath (V-UAS) and MPCNL in the treatment of renal stone.

MATERIALS AND METHODS

28 patients with 2-4 cm renal stone were treated using RIRS with 14/16 F V-UAS. The outcomes were compared to those who underwent MPCNL with 16 F Amplatz sheath using a matched-pair analysis in a 1 : 2 scenario. Matching criteria included stone size, location and laterality, gender, age, BMI, and degree of hydronephrosis. Patients' demographics, perioperative and postoperative characteristics, complications, stone-free rate (SFR), and auxiliary procedures were compared.

RESULTS

Mean operative times for the RIRS and MPCNL groups were 72.4 ± 21.3 minutes and 67.4 ± 25 minutes (P = 0.042). Postoperative pain was significantly less in the RIRS group. The initial SFR was 50% for the RIRS group and 73.2% for the MPCNL group (P = 0.035). The final SFR at postoperative three months improved to 89.3% for the RIRS group and 92.9% for the MPCNL group (P = 0.681). The auxiliary procedure rates were higher in the RIRS group (42.9% vs. 25%, P = 0.095). The overall complication rate in the RIRS group was lower, but the significant difference was not found.

CONCLUSION

In the treatment of 2-4 cm renal stone, using V-UAS in RIRS can improve surgical efficiency with lower postoperative early pain scores. Comparing with MPCNL, its initial SFR was more depressed, and there is still a trend towards requiring more auxiliary procedures to achieve comparable final SFR.

Preoperative urine culture - Is it necessary to prevent infectious complications following ureterorenoscopy?

To prevent postoperative infectious complications, a urinary tract infection should be either diagnostically excluded or treated prior to ureterorenoscopy (URS). URS is a frequently performed endoscopic surgery for urological stone removal. Although the urinary dipstick test represents a simple and cost-effective method to gain information about the presence of urinary tract infection, the prevailing procedure is the more expensive and more time-consuming method of urine culture. The aim of this retrospective single-center study was to compare two strategies of perioperative prophylaxes prior to URS and to evaluate their impact on postoperative infectious complications: I) Obtaining a urine culture in every patient prior to URS or II) only in case of a positive dipstick test. Therefore, we retrospectively compared 201 patients in two cohorts undergoing URS. In one cohort a urine culture was obtained only in case of a positive dipstick test of midstream urine sample and in the second cohort a urine culture was prepared for every patient regardless of the dipstick's test results. The study's end point was determined as "infectious failure" (IF), if more than one of the following criteria are fulfilled: postoperative fever, elevation of inflammation laboratory values, significant prolongation of hospital stay and readmission within short-notice. Simple and multiple logistic regressions were performed to evaluate the influence of patient characteristics and preoperative urine analysis strategy on the occurrence of IF. Patients with a score of the American Society of Anesthesiologists (ASA) > 2 had a nearly statistically higher risk (p = .09) to develop an IF than healthier patients with an ASA score ≤ 2. Prestenting was determined as a significant predictive factor (p = .04) for a postoperative IF. No difference in patients with or without IF was detected regarding the two preoperative urine analysis strategies. Sensitivity of dipstick test was 87.5% and the negative predictive value was 89.66%. We found that a negative urine dipstick test result obtained prior to URS eliminated the need for urine culturing in predicting postoperative infectious complication. This approach can reduce preoperative preparation-time and costs without affecting postoperative complication outcomes.

Comparative medico-economic study of reusable vs. single-use flexible ureteroscopes

PURPOSE

Reusable flexible-ureteroscopes (fURS) require personnel and budget for processing and repairing, whereas single-use fURS were recently developed. After exclusive reusable fURS since 2011, we experienced high repair costs and single-use fURS were therefore introduced in mid-2017. We aimed to evaluate economic and practical advantages and disadvantages of reusable versus single-use fURS.

MATERIALS AND METHODS

First, we evaluated the incidence of breakage and repairs of reusable fURS in 2017. We assessed the overall operational costs of reusable fURS including purchase, processing, and repairing in our institution from 2011 to 2017. Following our experience, we created a model to compare operation costs/procedure of single-use fURS with reusable fURS depending on repair costs.

RESULTS

In 2017, repair costs of reusable fURS increased by 345% compared with the period 2011-2016, causing: a median unavailability per reusable fURS of 200 days/year (100-249), median number of functioning fURS 0/5-3/5 per operating day, while unavailability of reusable fURS had become the first reason for cancellation of procedure. Since it was introduced, single-use fURS accounted for 59% of the flexible ureteroscopy activity. Taking into account the costs of processing, maintenance and repair, in 2011-2016 versus 2017, the single-use fURS was cost-effective compared with the reusable fURS until the 22nd procedure versus the 73rd procedure, respectively.

CONCLUSIONS

After years of exclusive reusable fURS, the rising incidence of breakage not only increased maintenance costs but also hampered daily activity owing to unavailability of the devices. The introduction of single-use with reusable fURS provided substantial help to maintain our activity.

Propensity Score-Matched Analysis Comparing Retrograde Intrarenal Surgery with Percutaneous Nephrolithotomy for Large Stones in Patients with a Solitary Kidney

PURPOSE

To evaluate the clinical efficacy, safety, and cost of retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) in the treatment for large renal stones in patients with a solitary kidney.

PATIENTS AND METHODS

In this study, 117 patients with a solitary kidney who had undergone PCNL or RIRS for renal stones larger than 2 cm between January 2010 and December 2016 were retrospectively evaluated. The patients' demographic data, clinical characteristics, and perioperative outcomes were collected through a review of their medical records. Forty-three patients treated with PCNL were compared to 43 patients treated with RIRS by propensity score-matched analysis. The stone-free rate, retreatment rate, complication rate, and efficacy quotient (EQ) were assessed in both groups.

RESULTS

Initial stone-free rate of the PCNL group after a single procedure was significantly higher compared with the RIRS group (74.42% vs 34.88%, p < 0.001), whereas there was no significant difference in the final stone-free rate after repeated procedures (90.70% vs 88.37%, p = 0.713). PCNL had a significantly lower retreatment rate than RIRS (16.28% vs 63.79%, p < 0.001), and the PCNL group underwent fewer procedures than the RIRS group (p < 0.001). Thus, PCNL group had a higher EQ (78.00% vs 53.52%). Although cost per procedure of PCNL was significantly higher compared with RIRS (p < 0.001), the total costs were comparable. Complication rate of RIRS was lower compared with PCNL with no statistical significance (p = 0.193), and acute kidney injury rates were also comparable (PCNL vs RIRS: 13.95% vs 6.98%, p = 0.533).

CONCLUSIONS

With fewer repeated surgical procedures, higher EQ, and comparable total costs, PCNL is recommended as the first choice for the treatment of large renal calculi in patients with a solitary kidney. As for specific indications such as anticoagulant drugs, RIRS is a safer choice with fewer complications and acceptable final stone-free rate.

Infectious Complications After Laser Vaporization of Urinary Stones During Retrograde Intrarenal Surgery Are Not Associated with Spreading of Bacteria into Irrigation Fluid but with Previous Use of Fluoroquinolones

BACKGROUND

The pathogenesis of infectious complications after retrograde intrarenal surgery (RIRS) is not fully understood.

OBJECTIVE

To evaluate spreading of bacteria into irrigation fluid and blood during RIRS for stone management and to correlate such spreading with infectious complications.

DESIGN, SETTING, AND PARTICIPANTS

From January to December 2017, 38 patients who underwent RIRS for stones in two urological units were enrolled in this prospective, longitudinal cohort study.

INTERVENTION

A urine culture was taken before surgery and antimicrobial prophylaxis was given in line with the European Association of Urology guidelines. Blood and irrigation fluid samples were collected at the start of the endoscopic procedure and every 30min during the procedure. All samples were microbiologically examined and findings were compared with clinical data.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

Symptomatic and asymptomatic urinary tract infectious complications were correlated with microbiological and clinical data, using Student t test or Mann-Whitney U test.

RESULTS AND LIMITATIONS

Ten patients showed significant bacterial growth in irrigation fluid samples (seven Escherichia coli, two Klebsiella pneumoniae, and one Pseudomonas aeruginosa). Eight patients (21%) got febrile urinary tract infections during hospital stay: two had bacterial growth in the irrigation fluid (25%) and one also had bacteremia (12.5%). No correlation was found either between the bacterial growth in the irrigation fluid samples and the urine cultures that were taken before the procedure, or between the bacterial growth in the irrigation fluid samples and the development of postoperative infectious complications. Previous use of fluoroquinolones and a history of urinary tract infections were associated with infectious complications after RIRS.

CONCLUSIONS

We demonstrated spreading of bacteria into the irrigation fluid during RIRS procedures, but this spreading was not associated with the development of infectious complications. Particular attention should be given to previous antibiotic treatment before administration of antimicrobial prophylaxis.

PATIENT SUMMARY

Bacterial spreading into irrigation fluid is a common finding during retrograde intrarenal surgery, but it is not associated with infectious complications after the procedure. Particular attention should be given to previous antibiotic treatment before administration of antimicrobial prophylaxis.

Factors affecting infectious complications following flexible ureterorenoscopy

In the present study, we aimed to clarify predictive factors that may cause postoperative infectious complications after flexible ureterorenoscopy (f-URS). In a 4-year prospective study, charts of patients who underwent f-URS between January 2014 and January 2018 for renal stone(s) in a tertiary academic center were reviewed. A standardized f-URS procedure was performed for all patients. Post-operative infectious complications including fever, sepsis and septic shock were categorized into same group. Patients with and without infectious complications were compared in the terms of preoperative, operative and post operative characteristics. In total, 463 patients who did not face infectious complications and 31 patients who faced infectious complications were enrolled into the study. The mean age was significantly lower in patients who did face infectious complications (34.8 vs 44.7 years old, p < 0.001). On the other hand, presence of renal abnormality was significantly more common in patients with infectious complications (12.3% vs 35.5%, p < 0.001). The mean operation time was 65.3 min in patients with infectious complications and significantly longer when compared with patients who did not face infectious complication (47.8 min, p < 0.001). Stone-free rate was significantly higher in patients without infectious complications (85.3% vs 77.5, p = 0.009). Multivariate regression analysis revealed that longer operation time ≥ 60 min, presence of renal abnormality and age ≤ 40 years were predictive factors for infectious complications following f-URS. The present study has demonstrated that operation time ≥ 60 min, presence of renal abnormality and patients with ≤ 40 years were significantly associated with infectious complications following f-URS.

Comparison of suctioning and traditional ureteral access sheath during flexible ureteroscopy in the treatment of renal stones

PURPOSE

To compare the efficiency and safety of suctioning ureteral access sheath (UAS) and traditional UAS during flexible ureteroscopy (FURS) for treatment of renal stones.

METHODS

Between January 2015 and December 2017, 165 patients who had renal stones successfully underwent FURS with suctioning UAS created by connecting a channel on the tail of the suctioning UAS to a vacuum device. The outcomes of these patients were compared with those of 165 patients undergoing FURS with traditional UAS using a 1:1 scenario matched-pair analysis. The matching parameters were age, gender and stone burden.

RESULTS

The baseline characteristics were homogeneous between the two groups. The suctioning UAS group had significantly higher SFR one day postoperatively (82.4% vs. 71.5%; P = 0.02), but SFR 1 month postoperatively was comparable in the two groups (P = 0.13). The incidence of overall complications was significantly higher in the traditional UAS group (24.8% vs 11.5%; P < 0.001). Regarding individual complications, the traditional UAS group was associated with a significantly higher incidence of fever (13.9% vs 5.5%; P = 0.009) and urosepsis requiring only additional antibiotics (6.7% vs 1.8%; P = 0.029). No significant difference was noted in the incidence of septic shock, hematuria, steinstrasse or ureteral stricture. The suctioning UAS group had significantly shorter operative time (49.7 + 16.3 min vs. 57.0 ± 14.0 min; P < 0.001).

CONCLUSIONS

Compared to traditional UAS during FURS for treating renal stones, suctioning UAS had the advantages of higher SFR 1 day postoperatively, a lower incidence of infectious complications and a shorter operative time. Further well-designed studies are required to confirm the results.

The application of a single-use fiberoptic flexible ureteroscope for the management of upper urinary calculi

OBJECTIVE

To evaluate the clinical outcomes with a Chinese single-use fiberoptic flexible ureteroscope (YouCare Tech) from a prospective database.

MATERIALS AND METHODS

A prospective study was conducted in a single center in China between January 2016 and October 2017. All consecutive patients who underwent flexible ureteroscopy performed by YouCare flexible ureteroscope were analyzed. Patients' demographics, clinical characteristics, intraoperative parameters, postoperative complications, and stone-free rate were evaluated and recorded. Stone-free status was defined as no visible stones or clinically insignificant residual stones < 2 mm on a postoperative image study.

RESULTS

A total of 684 procedures were performed for 653 patients (31 patients had bilateral stones). A double J stent had been previously placed in 431 patients. The location of the calculi was upper calyx, middle calyx, lower calyx, and renal pelvis and proximal ureter in 74, 101, 211, 115, and 183 patients, respectively. The median operative time was 52 min. The postoperative stone-free rate for the first 2 weeks after surgery was 78.5%, which increased to 91.1% at the first month. The overall stone-free rate was 95.2%. The complication rate was minor and short-term, such as gross hematuria or flank pain.

CONCLUSION

YouCare flexible ureteroscope can be considered effective and safe in the treatment of both upper ureteral and renal stones in selected patients. Further evaluation of comparison with other FURS's surgical outcomes and cost-effectiveness analysis will help to present the best utility of this single-use FURS in clinical practice.

Tailored perioperative antimicrobial prophylaxis in urological surgery: myth or reality?

PURPOSE OF REVIEW

The controversies surrounding perioperative antimicrobial prophylaxis (AMP) are about the use and especially misuse of antibiotics. The overall lack of evidence to facilitate a rational perioperative AMP policy in urological surgery and the postoperative infectious complications remain a challenge. Therefore, a basic tool to aid decision-making would be useful. A model based on the patients' risk factors, the level of contamination and grading of surgical procedures is discussed.

RECENT FINDINGS

A series of studies have shown that infectious complications and healthcare-associated infections remain consistently at an average of 10%, with a great variation in frequency dependent on the patients' preoperative status and the type, severity and contamination level of the surgical procedure. Preoperative patient assessment and preparation are key factors for well tolerated surgery and recovery. Adherence to the guidelines appears to reduce both the prescription of antimicrobials and the total costs without risking the patient outcome. Several studies of a series of interventions such as cystoscopy, endoscopic stone surgery and selected clean-contaminated interventions give support to the model. Bacteriuria, upgrading the patient to the contaminated level, requires preoperative control.

SUMMARY

The discussed model assists the urologists in decision-making on perioperative AMP and contributes to a responsible use of antibiotics.

Extracorporeal shock wave lithotripsy versus flexible ureterorenoscopy in the treatment of untreated renal calculi

Background

The reported success rates for treatments of kidney stones with either extracorporeal shock wave lithotripsy (ESWL) or flexible ureterorenoscopy (URS) are conflicting. We aimed to compare the efficacy and safety of ESWL and URS for previously untreated renal calculi.

Methods

All patients treated with ESWL or URS at our tertiary care centre between 2003 and 2015 were retrospectively identified. Patients with previously untreated kidney stones and a stone diameter of 5–20 mm were included. Stone-free, freedom from reintervention and complication rates were recorded. Independent predictors of stone-free and freedom from reintervention rates were identified by multivariable logistic regression and a propensity score-matched analysis was performed.

Results

A total of 1282 patients met the inclusion criteria, of whom 999 (78%) underwent ESWL and 283 (22%) had URS. During post-operative follow-up, only treatment modality and stone size could independently predict stone-free and freedom from reintervention rates. After propensity score matching, ESWL showed significantly lower stone-free rates [ESWL (71%) versus URS (84%)] and fewer patients with freedom from reintervention [ESWL (55%) versus URS (79%)] than URS. Complications were scarce for both treatments and included Clavien Grade 3a in 0.8% versus 0% and Grade 3b in 0.5% versus 0.4% of ESWL and URS treated patients, respectively.

Conclusions

Treatment success was mainly dependent on stone size and treatment modality. URS might be the better treatment option for previously untreated kidney stones 5–20 mm, with similar morbidity but higher stone-free rates and fewer reinterventions than ESWL.

RIRS in the elderly: Is it feasible and safe?

BACKGROUND

The aim of this study was to compare the safety and efficacy of RIRS in men ≥65 years to those <65 years.

MATERIALS AND METHODS

Patients who underwent RIRS were prospectively collected from March 2013 to March 2014 in 5 European centers. Perioperative outcomes and complications in elderly men were compared with men <65 years. Univariable and multivariable analyses were performed for factors predicting overall complications. The groups were compared using Mann-Whitney U test. Categorical variables were compared using chi-squared test and the Yates correction or the Fisher's exact test.

RESULTS

A total of 399 patients with renal stones were included, 308 (77.19%) were aged <65 years, 91 (22.8%) were aged ≥65 years. Elderly patients were more likely to have higher ASA scores (35.7% vs 92.3%; p < 001), Charlson Comorbidity Index (1.8 vs. 5.2, p < 0.001), hyperlipidemia (10.06% vs. 30.76%; p = 0,0005) and coronary heart disease (5.51% vs. 17.58; p = 0.005) compared to younger cohort. Perioperative outcomes (stone free rate, operative time and re-intervention rate) did not show differences between the two groups (p > 0.05). Surgical and medical complication rates were similar between the cohorts (14.28% vs 9.89%; p = 0.38). Multivariate analysis did not identify any predictive factors of complications among the two groups (p > 0.05).

CONCLUSIONS

In this study, elderly RIRS patients had comparable short term efficacy and perioperative complications to younger patients, despite a higher prevalence of comorbidity. Age itself should not be considered as a risk factor for the development of complications in patients undergoing RIRS for renal stone.