Residual Stone Fragments Research Articles

Factors influencing operative time for mini-endoscopic combined intrarenal surgery for renal stones.

Mini-endoscopic combined intrarenal surgery (ECIRS) offers improved advantages in the treatment of renal stones. However, the factors influencing the operative time remain poorly understood. This study aimed to identify the factors that enhance treatment planning and minimize complications. Clinical data from consecutive patients who underwent mini-ECIRS for renal stones and achieved a stone-free status between 2015 and 2021 at three high-volume centers in Japan were analyzed. The final treatment outcome was evaluated by computed tomography imaging at postoperative 1month, and a successful outcome was defined as complete stone-free or residual stone fragments < 4mm. Logistic and linear regression models were used to predict the operative duration of mini-ECIRS. An operative time of ≥ 120min was significantly associated with punctured pole and body mass index (BMI), and septic shock was only observed in patients with operative times of ≥ 120min. The multivariate model for the operative time for mini-ECIRS identified five clinical factors: punctured pole, number of stones, number of involved calyces, BMI, and preoperative nephrostomy. We believe these findings will help surgeons and patients plan suitable treatment strategies, predict the additional need for a second mini-ECIRS or retrograde intrarenal surgery alone, and avoid severe complications.

Impact of Residual Stone Fragments on Risk of Unplanned Stone Events Following Percutaneous Nephrolithotomy.

Purpose: Residual stone fragments are common after percutaneous nephrolithotomy (PCNL), however, there is an unclear relationship between the presence of these residual stone fragments and the risk of unplanned stone events (USE). We investigated how the size of the largest residual stone fragment (LRSF) impacts the risk of USE post-PCNL. Materials and Methods: We conducted a retrospective cohort study of PCNL between 2018 and 2022. Preoperative computed tomography of the abdomen and pelvis (CTAP) imaging and postoperative CTAP imaging were reviewed. The primary outcome was the incidence of postoperative USE, defined as stone-related emergency department visits or unplanned stone procedures. LRSF were stratified by five thresholds (no postoperative stone fragments vs ≥0 mm, <2 vs ≥2 mm, <3 vs ≥3 mm, <4 vs ≥4 mm, and <5 vs ≥5 mm), and Cox regression was used to compare the impact of these thresholds on the risk of USE. Results: After exclusions, we identified 138 patients who underwent PCNL during the study period; 42 patients had a USE. When applying a 4 mm threshold, 52% of patients with LRSF ≥4 mm experienced USE vs 21% with LRSF <4 mm (log-rank p = 0.0004); similarly, with a 5 mm threshold, 62.5% with LRSF ≥5 mm had such events compared with 21% with LRSF <5 mm (log-rank p < 0.00001). A larger LRSF was associated with a greater risk of having a USE. Conclusion: After PCNL, larger residual stone fragments, particularly those ≥4 mm, are associated with an increased risk of USE. These results demonstrate the value of identifying residual fragments in predicting USE.

Efficacy of flexible ureterorenoscopy in treating multiple renal stones: a cohort study.

While the efficacy of flexibleureterorenoscopy (URS) in managing solitary kidney stones (KSs) is widely acknowledged, its effectiveness intreating multiple stones has scarcely been investigated. This study aims to assess the effectiveness and safety of retrogradeintrarenal surgery (RIRS) utilizing flexible URS and laser lithotripsy in the management of multiple KSs. Methods: This study was a single-group cohort study conducted on patients with multiple KSs who underwent treatment withRIRS using flexible URS and laser lithotripsy. Stone-free status was considered as the lack of residual stone fragments or anyresidual stone of any size. The first follow-up appointment was arranged 3-4 weeks following the procedure. If significant residualstones were present, patients underwent reintervention within 2-4 weeks. A total of 110 patients with multiple KSs were included. The mean stone burden was 27.5 ± 7.9 mm, and the mean duration of the operation was 54.9 ± 19.7 minutes. Seven cases(6.3%) experienced intraoperative complications, while postoperative complications were found in eight cases (7.3%). Afterfour weeks, a stone-free rate (SFR) was documented in 80.9% of the cases, and this rate increased to 93.6% after three months.The SFR after three months was significant with Guy's stone score (p < 0.001); however, it did not reach a significant level with any other parameters. Conclusions: The RIRS with flexible URS may be an effective and potentially safe procedure for treating multiple KSs. It mayyield a favorable SFR with an acceptable complication rate.

Initial Clinical Experience With a Novel Robotically Assisted Platform for Combined Mini-Percutaneous Nephrolithotomy and Flexible Ureteroscopic Lithotripsy.

We sought to evaluate the technical feasibility of performing a combined robotically assisted mini-percutaneous nephrolithotomy (PCNL) and flexible ureteroscopy (URS) procedure by a single urologist using the MONARCH Platform, Urology (Johnson & Johnson MedTech, Redwood City, California). In this prospective, first-in-human clinical trial, 13 patients underwent robotically-assisted PCNL for renal calculi at the University of California-Irvine, Department of Urology. Successful completion of the procedure was assessed as the primary endpoint. Postoperative adverse events were monitored for 30 days following the completion of the procedure. Stone ablation efficiency was evaluated on postoperative day 30 with low-dose 2-3 mm slice CT scans. Patients were classified according to the maximum length of their residual stone fragments as either absolute stone-free (Grade A), < 2 mm remnants (Grade B), or 2.1-4.0 mm remnants (Grade C). The combined robotic mini-PCNL and URS procedure was successfully completed in 12 of 13 procedures. No robotic device-related adverse events occurred. Preoperative stone burden was quantified by both maximum linear measurement (median 32.8 mm) as well as by CT-based volume (median 1645.9 mm3). Using the unique robotically assisted targeting system, percutaneous access was gained directly through the center of the renal papilla in a single pass in all cases. Median operative time was 187 minutes (range: 83-383 minutes). On postoperative day 30, a 98.7% (range: 72.9%-100.0%) volume reduction was achieved, with 5 Grade A (38.5%), 1 Grade B (7.7%), and 2 Grade C (15.4%). Three patients experienced complications (2 grade 1 and one grade 2 Clavien-Dindo). Our preliminary investigation demonstrates the safety, efficacy, and feasibility of a unique robotic-assisted combined mini-PCNL and URS platform.

Effect of Residual Stone Fragments on Patient-Reported Quality of Life after Endoscopic Kidney Stone Surgery

Effect of Residual Stone Fragments on Patient-Reported Quality of Life after Endoscopic Kidney Stone Surgery

Consensus statement addressing controversies and guidelines on pediatric urolithiasis.

We aimed to investigate controversial pediatric urolithiasis issues systematically, integrating expert consensus and comprehensive guidelines reviews. Two semi-structured online focus group meetings were conducted to discuss the study's need and content, review current literature, and prepare the initial survey. Data were collected through surveys and focus group discussions. Existing guidelines were reviewed, and a second survey was conducted using the Delphi method to validate findings and facilitate consensus. The primary outcome measures investigated controversial issues, integrating expert consensus and guideline reviews. Experts from 15 countries participated, including 20 with 16+ years of experience, 2 with 11-15years, and 4 with 6-10years. The initial survey identified nine main themes, emphasizing the need for standardized diagnostic and treatment protocols and tailored treatments. Inter-rater reliability was high, with controversies in treatment approaches (score 4.6, 92% agreement), follow-up protocols (score 4.8, 100% agreement), and diagnostic criteria (score 4.6, 92% agreement). The second survey underscored the critical need for consensus on identification, diagnostic criteria (score 4.6, 92% agreement), and standardized follow-up protocols (score 4.8, 100% agreement). The importance of personalized treatment in pediatric urolithiasis is clear. Prioritizing low-radiation diagnostic tools, effectively managing residual stone fragments, and standardized follow-up protocols are crucial for improving patient outcomes. Integrating new technologies while ensuring safety and reliability is also essential. Harmonizing guidelines across regions can provide consistent and effective management. Future efforts should focus on collaborative research, specialized training, and the integration of new technologies in treatment protocols.

Residual Stone Fragments after Percutaneous Nephrolithotomy: Shockwave Lithotripsy vs Retrograde Intrarenal Surgery

Abstract Background Post-PCNL treatment for 0.5-1.5 cm calculi is contentious. SWL has noninvasiveness, less anaesthetic, and improved subjective acceptability, but a lower stone-free rate and higher retreatment rate (RR). Retrograde intrarenal surgery (RIRS) is increasingly employed to treat after PCNL residual calculi with a greater success rate (SR), but with disadvantages of invasiveness and anaesthesia. Aim To compare the outcomes of retrograde intrarenal surgery (RIRS) to extracorporeal shockwave lithotripsy (SWL) for treating patients with RSFs after a previous standard PCNL. Subject and Methods A retrospective study of 70 adult patients with residual stone fragments after a standard PCNL submitted to RIRS or SWL (35 patients per each group) in ain shams university hospitals and police hospitals. Results There no significant difference between the groups regarding ASA, PCNL Guy’s classification, percutaneous tracts, stone composition and postoperative complications. There a significant difference between the groups regarding inferior calyx located stone and postoperative hospital stay. &amp;gt;2 mm stones were significantly more frequent in SWL group compared to RIRS group. Conclusion From the findings of this study we can conclude that RIRS has better SFR for the treatment of RSFs after standard PCNL

Association of health-related quality of life with urinary tract infection among kidney stone formers

Kidney stones and infections significantly affect patients’ health-related quality of life (HRQOL); however, the relationship between urinary tract infections (UTIs) and HRQOL in patients with kidney stones remains unclear. This study aimed to investigate the relationship using the validated Chinese version of the Wisconsin Stone Quality of Life questionnaire (C-WISQOL). We prospectively recruited 307 patients with kidney stones to complete the C-WISQOL before and after stone removal. The participants were diagnosed with UTI based on the presence of pyuria or bacteriuria with or without clinical symptoms. The psychometric properties of the C-WISQOL were statistically analyzed. Multivariate linear regression was used to predict the risk factors for impaired HRQOL in patients with stones and UTIs. The questionnaire is a reliable and robust tool for evaluating HRQOL in Chinese-speaking patients with urolithiasis. The UTI and kidney stone co-occurrence was significantly associated with female sex, diabetes mellitus, more previous stone events, higher antibiotic usage, positive stone- or UTI-related symptoms, and postoperative residual stones. The preoperative C-WISQOL scores and improvement in the HRQOL after stone removal in patients clinically diagnosed with UTI were significantly inferior to those in patients without UTI. The regression analyses showed that worse HRQOL was predicted by more previous stone events and positive stone- or UTI-related symptoms. In contrast, the presence of diabetes mellitus and postoperative residual stone fragments predicted a lower improvement in the HRQOL. These findings underscore UTI’s harmful impact on perioperative HRQOL in patients with kidney stones and could help strategies benefit those patients.

Navigating Entire Collecting System During Supine Percutaneous Nephrolithotomy: Is Rigid Nephroscopy Enough? A Prospective Study by International Alliance of Urolithiasis Supine Percutaneous Nephrolithotomy Working Group.

Background: During percutaneous nephrolithotomy (PCNL), accessibility to the entire collecting system is crucial to check the presence of any residual stone fragments. In this study, we aimed to identify the rate of accessibility of all caliceal cavities using lower-, middle- and, upper-pole punctures and the eventual benefit of simultaneous utilization of retrograde/antegrade flexible nephroscopy. Materials and Methods: Data of patients undergone supine PCNL in five different institutions were collected prospectively. Access status to other poles of the kidney with a rigid nephroscope, antegrade access status to the other poles of the kidney with a flexible nephroscope, or retrograde access with a flexible ureterorenoscope were all evaluated together with detection of residual fragments. Access status to the other poles of the kidney with anterograde and retrograde approaches were compared. Results: Data of 226 patients were analyzed and stone-free status was achieved in 207 (91.6%) of the patients. The entire collecting system could be successfully approached by a rigid nephroscope in 50% of the cases through middle-pole puncture. This rate was significantly higher than that of lower-pole puncture (37.1%) and upper-pole puncture (28.1%) (P = .035). The successful approach to the entire collecting system with retrograde ureterorenoscopy was possible in 97.6% of the cases, while the successful approach was possible in 48 of the 60 cases (80%) with the retrograde approach (P < .0001). Conclusions: During PCNL, evaluation of the entire collecting system with rigid nephroscopy is not possible in a significant portion of the patients. We believe that the application of flexible nephroscopy, particularly via retrograde approach improves the stone-free rates.

SLAP Trial: Shock Wave Lithotripsy and Mechanical Percussion Therapy Post ESWL for Renal Calculi.

We conducted a prospective randomised control trial. Included patients were males and females greater than 18 years of age with single or multiple ipsilateral renal calculi of total ≤10 mm on plain X-ray and noncontrast CT KUB. ESWL was performed at a single centre, at supine position under general anaesthesia with maximum 3000 shocks at a rate of 100 shocks per minute. Patients were discharged and randomised to either the control arm or MPI therapy. MPI therapy was self-directed in a home setting for 10 minutes a day, three times per week. Both arms had standard follow-up at 12 weeks with a plain X-ray KUB. Patients in the control group were offered cross over to the MPI arm after 12 weeks if residual stone fragments were detected. Statistical analysis was performed using SPSS software via Chi squared and Fisher's exact tests. Ethical approval was obtained via the Prince Charles Hospital HREC Committee, HREC/2022/QPCH/84961. 70 patients met inclusion criteria and underwent ESWL, and 5 were withdrawn. 33 patients were randomised to the MPI group and 32 to the control group. MPI significantly increased the stone clearance rate anywhere in the kidney (87.9% in the MPI group versus 59.4% in the control group, p=0.089), as well as the clearance rate in the lower pole (91.7% in the MPI group versus 63.2% in the control group, p=0.022). Delayed percussion did not improve the clearance rate over primary percussion (p=0.835). This study has shown that MPI can be effectively performed in a home setting without the need for medical supervision and results in improved stone clearance rates post ESWL. The main limitations to the study were the use of X-ray over CT during the follow-up and variability in MPI compliance and administration. Further research is warranted into standardising home MPI protocols. This trial is registered with ANZCTR387061.

Comparison of the effectiveness of two adjustable negative pressure ureteral access sheaths combined with flex ureteroscopy for ≤ 2cm renal stones.

To compare the safety and effectiveness of the combination of intelligent intrarenal pressure control platforms (IPCP) and flexible ureteral access sheath (FUAS) combined with retrograde intrarenal surgery (RIRS) for the treatment of renal stones less than 2cm. We retrospectively collected 383 patients with renal stones who underwent RIRS in our department from June 2022 to October 2023. Inclusion criteria: stone length or the sum of multiple stone lengths ≤ 2cm. Finally, 99 cases were included and divided into an IPCP group (n = 40) and FUAS group (n = 59) based on surgical methods. The main endpoint was the stone-free rate (SFR) at third months after surgery, with no residual stones or stone fragments less than 2mm defined as stone clearance. The secondary endpoints were surgical time and perioperative complications, including fever, sepsis, septic shock, and perirenal hematoma. There was no statistically significant difference in general information between the two groups, including age, gender, body mass index, comorbidities, stone side, stone location, stone length, urine bacterial culture, and hydronephrosis. The operation time for IPCP group and FUAS group was 56.83 ± 21.33 vs 55.47 ± 19.69min (p = 0.747). The SFR of IPCP group and FUAS group on the first postoperative day was 75.00% vs 91.50% (p = 0.024). The SFR was 90.00% vs 94.90% in the third month (p = 0.349).In IPCP group, there were 11 cases with stones located in the lower renal calyces and 17 cases in FUAS group. The SFR of the two groups on the first day and third months after surgery were 45.50% vs 88.20% (p = 0.014) and 63.60% vs 94.10% (p = 0.040), respectively, with statistical differences. For kidney stones ≤ 2cm, there was no difference in SFR and the incidence of infection-related complications between IPCP and FUAS combined with RIRS, both of which were superior to T-RIRS. For lower renal caliceal stones, FUAS has a higher SFR compared to IPCP.

Safety and Efficacy of Bilateral Tubeless Supine Mini-Percutaneous Nephrolithotomy for the Management of Bilateral Renal Calculi in Renal Failure Patients

Background: To evaluate the safety, efficacy, feasibility, stone-free rate, and complications of bilateral tubeless supine mini-percutaneous nephrolithotomy (M-PCNL) for bilateral multiple renal calculi with renal failure as a single-stage procedure. Materials and Methods: We conducted aretrospective study from January 2020 to March 2022 in adult patients with bilateral renal or proximal ureteric calculi with renal failure who were subjected to bilateral supine tubeless M-PCNL. Patients on regular hemodialysis before the procedure were excluded. Data regarding the demographic profile, stone characteristics on non-contrast computed tomography (NCCT), duration of surgery, complications, and auxiliary procedures were retrieved from clinical records. Residual stone fragments of≤4mm in NCCT were considered clinically insignificant. The Clinical Research Office of the Endourological Society validation ofClavien score for PCNL complications was used. Results: A total of twenty-seven patients with a mean age of 45.9years were included in this study. The mean size of stone diameter per renal unit was 2.4 ± 0.4 cm. The mean preoperative serum creatinine was 2.8 mg/dL. A total of 62 tracts and 27 sessions were required for complete treatment of all 54 renal units in the 27 successfully treated patients. The average operating time was 75 (52–122) min on both sides. Serum creatinine drop at onemonth postsurgery was statistically significant (p &lt; 0.0001). Mean hospitalization time was 3.6 days [3–6 days]. The primary stone-free rate was 92.5%. Grade I, II, and IVA complications were recorded in three (11.1%), eight (29.6%), and two (7.4%) patients, respectively. Conclusion: Bilateral tubeless supine M-PCNL for bilateral renal calculi in selective patients with renal failure in a single session is a safe, feasible, and effective option which can be carried out without increased morbidity and can be attempted if the first-side M-PCNL has gone smoothly within a reasonable amount of time.

Models to predict the surgical outcome of mini-ECIRS (endoscopic combined intrarenal surgery) for renal and/or ureteral stones

To establish a safer and more efficient treatment strategy with mini-endoscopic combined intrarenal surgery (ECIRS), the present study aimed to develop models to predict the outcomes of mini-ECIRS in patients with renal and/or ureteral stones. We retrospectively analysed consecutive patients with renal and/or ureteral stones who underwent mini-ECIRS at three Japanese tertiary institutions. Final treatment outcome was evaluated by CT imaging at 1 month postoperatively and stone free (SF) was defined as completely no residual stone or residual stone fragments ≤ 2 mm. Three prognostic models (multiple logistic regression, classification tree analysis, and machine learning-based random forest) were developed to predict surgical outcomes using preoperative clinical factors. Clinical data from 1432 ECIRS were pooled from a database registered at three institutions, and 996 single sessions of mini-ECIRS were analysed in this study. The overall SF rate was 62.3%. The multiple logistic regression model consisted of stone burden (P < 0.001), number of involved calyces (P < 0.001), nephrostomy prior to mini-ECIRS (P = 0.091), and ECOG-PS (P = 0.110), wherein the area under the curve (AUC) was 70.7%. The classification tree analysis consisted of the number of involved calyces with an AUC of 61.7%. The random forest model showed that the top predictive variable was the number of calyces involved, with an AUC of 91.9%. Internal validation revealed that the AUCs for the multiple logistic regression model, classification tree analysis and random forest models were 70.4, 69.6 and 85.9%, respectively. The number of involved calyces, and a smaller stone burden implied a SF outcome. The machine learning-based model showed remarkably high accuracy and may be a promising tool for physicians and patients to obtain proper consent, avoid inefficient surgery, and decide preoperatively on the most efficient treatment strategies, including staged mini-ECIRS.

COMPLICATIONS OF MINIMALLY INVASIVE PERCUTANEOUS NEPHROLITHOTOMY IN THE TREATMENT OF KIDNEY STONES AT MILITARY HOSPITAL 103

Objectives: To evaluate the complications of the minimally invasive percutaneous nephrolithotomy (mini-PCNL) in treating kidney stones at Military Hospital 103. Methods: A prospective, longitudinal study on 286 kidney stone patients operated using the mini-PCNL technique at Military Hospital 103 from July 2017 to July 2019. Results: After mini-PCNL, most patients had no complication (77.62%). Bleeding and fever after mini-PCNL were the two most common complications; there were 35 patients with intraoperative bleeding and no need for blood transfusion (12.24%) and 15 patients with fever after surgery and no chills (5.24%). The stone size affected its clearance rate but did not affect fever and bleeding after mini-PCNL. After mini-PCNL, the mean values of Red Blood Cell (RBC), Hemoglobin (HGB), and Hematocrit (HCT) decreased from 4.75 ± 0.53 T/L, 140.38 ± 15.38 g/L, and 0.42 ± 0.04 L/L to 4.25 ± 0.44 T/L, 125.05 ± 13.36 g/L, and 0.38 ± 0.04 L/L, respectively. Conclusion: After mini-PCNL, the complication rate was 22.38%. Bleeding and fever after mini-PCNL were the two most common complications, with 46 patients (16.08%) and 18 patients (6.29%), respectively. The residual stone fragments were 19.58%. The stone size affected its clearance rate but did not affect fever and bleeding after mini-PCNL

Supine mini percutaneous nephrolithotomy in horseshoe kidney.

The percutaneous nephrolithotomy (PCNL) in Horseshoe kidneys (HSK) is usually performed in the prone position, allowing entry through the upper pole and providing good access to the collecting system. However, in patients with normal kidney anatomy, the supine position is reliable and safe in most cases, but it is unknown whether the supine position is adequate in patients with HSK. The purpose of this study was to describe the results of PCNL in HSK in three different surgical institutions and to evaluate the impact of supine position during surgery, comparing pre-operative and post-operative data, complications, and stone status after surgery. Between 2017 and 2022, a total of 10 patients underwent percutaneous renal surgery for stone disease in HSK. All patients were evaluated pre- and post- operatively with non-contrast CT. we evaluated patients (age and gender), stones characteristics (size, number, side, site and density ), and outcomes. The change in haemoglobin, hematocrit, creatinine and eGFr were assessed between the most recent preoperative period and the first postoperative day. Procedure success was defined as stone-free or presence of ≤4 mm fragments (Clinically Insignificant residual Fragments - CIrF). Complications were registered and classified according to Clavien-dindo Grading System, during the 30 - day postoperative period and Clavien scores ≥ 3 were considered as major complications. Statistical analysis was performed using "r 4.2.1" software, with a 5% significance level. we also compared pre-operative and post-operative data using "wilcoxon signedrank test". No statistical difference was observed between preoperative and post-operative renal function data. At one post operative day CT scan, an overall success rate of 100% was registered. 9/10 patients were completely free from urolithiasis (stone-free rate: 90%), while 1/10 patients had ≤4 mm residual stone fragments (CIrF rate: 10%). No cases of intraoperative complications were registered. Post-operative complications were reported in 1/10 patients. A patient developed urosepsis (defined as SIrS with clinical signs of bacterial infections involving urogenital organs - Clavien-dindo Grade II) after procedure, and was treated with intravenous antibiotic therapy successfully. Conclusions: This study shows that in patients with HSK mini- PCNL in supine position allows to achieve good stone free rate with a very low morbidity. According to our series, the described technique for PCNL in HSK should be an option. Nevertheless these results must be confirmed by further studies.

Intraoperative Assessment of Stone Free Status for Percutaneous Nephrolithotomy Surgery: Surgeon’s Eye

Objective: In patients who underwent percutaneous nephrolithotomy(PNL),it was aimed to determine the accuracy of the surgeon's intraoperative stone-free status(SFS) prediction,the factors affecting it,the predictors that caused the wrong estimation, and finally to evaluate the reliability of the "surgeon's eye".&#x0D; &#x0D; Material and Methods: The data of 1025 patients who underwent PNL and met the inclusion criteria were evaluated retrospectively.Since the basis of our study was based on the evaluation of the surgeon's stone-free prediction,patients identified as "absence of residual stone fragment(RF)" by the surgeon were grouped and compared with postoperative computed tomography imaging according to the presence of RF.&#x0D; &#x0D; Results: Sensitivity, specificity, positive predictive value and negative predictive value were calculated as 67.87%, 96.23%, 91.67% and 83.04%, respectively.In our study, it was found that the "surgeon's eye" predicted SFS incorrectly at a rate of 16.9%.There was no statistically significant correlation between gender,stone side,stone density and hemoglobin decrease between the two groups.Stone size,operation time,fluoroscopy time,location of the stone,number of stones in the calyces and GUY's stone score(GSS) were statistically significantly associated with "surgeon's eye".As a result of multivariate logistic regression analysis of the parameters that were found to have a statistically significant relationship with the surgeon's eye,stone size,the number of stones in the calyces and GSS were significant predictors.&#x0D; &#x0D; Conclusion: The most important predictors of "surgeon's eye" in PNL were stone size,number of stones in the calyces and GSS. These predictors can be used as an effective criterion in the use of methods to reduce radiation exposure in postoperative imaging of patients who are predicted to be stone-free.

Ultrasound-Only Percutaneous Nephrolithotomy Is Safe and Effective Compared to Fluoroscopy-Directed Percutaneous Nephrolithotomy.

Introduction: Outcomes after ultrasound-only percutaneous nephrolithotomy (PCNL), in which no fluoroscopy is used, are not well known. The goal of this study was to compare outcomes of ultrasound-only and fluoroscopy-directed PCNL. Materials and Methods: Prospectively collected data from the Registry for Stones of the Kidney and Ureter database were reviewed for all patients who underwent PCNL at one academic center from 2015 to 2021. Primary outcomes were complications and stone-free rates (no residual fragments ≥3 mm). Results: Of the 141 patients who underwent ultrasound-only PCNL and 147 who underwent fluoroscopy-directed PCNL, there was no difference in complication rates (15% vs 16%, p = 0.87) or stone-free status (71% vs 65%, p = 0.72), respectively. After adjusting for body mass index, American Society of Anesthesiologists (ASA), stone size, and stone complexity by Guy score, ultrasound-only PCNL was not associated with any increased odds of complications (odds ratio [OR] 0.7, 95% confidence interval [CI] 0.3-1.6, p = 0.41) or residual stone fragments ≥3 mm (OR 1.0, 95% CI 0.5-1.9, p = 0.972) compared with fluoroscopy-directed PCNL. Ultrasound-only PCNL was associated with shorter operative time (median 99.5 vs 126 minutes, p < 0.001), and the use of ultrasound remained a significant predictor of short operative time (<100 minutes) after controlling for supine positioning, stone size, and stone complexity by Guy score (OR 2.31, 95% CI 1.01-5.29, p = 0.048). Patients in the ultrasound-only group were spared a mean radiation exposure dose of 10 mGy per procedure. Conclusions: Ultrasound-only PCNL is safe and achieves similar stone-free rates compared with fluoroscopy-directed PCNL with the added benefit of avoidance of radiation.

PD28-03 EFFICACY AND SAFETY OF A MAGNETIC HYDROGEL FOR STONE FRAGMENT REMOVAL: AN IN VITRO AND IN VIVO STUDY

You have accessJournal of UrologyCME1 Apr 2023PD28-03 EFFICACY AND SAFETY OF A MAGNETIC HYDROGEL FOR STONE FRAGMENT REMOVAL: AN IN VITRO AND IN VIVO STUDY Daniel Massana Roquero, T. Jessie Ge, Grace H. Holton, Kathleen E. Mach, Zachary Kornberg, Ryan Sun, Simon Conti, Shan X. Wang, and joseph C. Liao Daniel Massana RoqueroDaniel Massana Roquero More articles by this author , T. Jessie GeT. Jessie Ge More articles by this author , Grace H. HoltonGrace H. Holton More articles by this author , Kathleen E. MachKathleen E. Mach More articles by this author , Zachary KornbergZachary Kornberg More articles by this author , Ryan SunRyan Sun More articles by this author , Simon ContiSimon Conti More articles by this author , Shan X. WangShan X. Wang More articles by this author , and joseph C. Liao joseph C. Liao More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003313.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Ureteroscopic laser lithotripsy is the standard treatment for kidney stones<2 cm. Following lithotripsy, fragments<3 mm are often left behind due to limitations of standard stone retrieval tools and time. Residual stone fragments that do not pass contribute to recurrence. We have developed MagSToNE, an integrated stone fragment removal system consisting of a magnetic hydrogel to coat and magnetize stone fragments and a magnetic wire for extraction. Here we compare MagSToNE with standard nitinol basket extraction in an in vitro model and assess the safety of the approach in vivo in a porcine model. METHODS: Stone fragments (15-30, < 3 mm) were loaded in an ex vivo kidney model to compare ureteroscopic removal time and efficiency using MagSToNE and a conventional basket. With APLAC approval MagSToNE was assessed in vivo in porcine models. Fragments were introduced endoscopically to the kidneys of female pigs under general anesthesia. Magnetic hydrogel components were injected via flexible ureteroscopy, and magnetized stones were captured with a magnetic wire inserted through the working channel of the ureteroscope. Pigs were immediately euthanized or monitored for up to 72 hours post-procedure. Blood was collected at regular intervals, starting at hydrogel injection, for complete blood count (CBC) and metabolic panels. After nephrectomy, kidneys were bivalved for gross examination and processed for histology. RESULTS: In the in vitro model, we found that MagSToNE provided a faster (up to 57 %) and more efficient approach for extraction of kidney stone fragments than conventional basketing. Further, we demonstrated the feasibility of MagSToNE in in vivo porcine models. The injection catheter and magnetic wire (1 mm diameter) showed excellent compatibility with a disposable clinical ureteroscope, and magnetized fragments were removed through the ureteral access sheath. Initial results from in vivo MagSToNE application indicate that the hydrogel and extraction method are safe as no significant changes in vitals, blood count, or metabolic serum chemistries were observed in the porcine models. Visual inspection of the bivalved kidneys post procedure confirmed the absence of visible hydrogel. Survival studies in the porcine model are ongoing to further assess the safety of MagSToNE. CONCLUSIONS: MagSToNE is a promising approach to render patients stone free during ureteroscopy. We demonstrated that MagSToNE is superior to basketing in model systems, and we applied our technology in vivo to demonstrate the safe magnetic extraction of kidney stone fragments. Source of Funding: NIH R21DK131776 © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e819 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Daniel Massana Roquero More articles by this author T. Jessie Ge More articles by this author Grace H. Holton More articles by this author Kathleen E. Mach More articles by this author Zachary Kornberg More articles by this author Ryan Sun More articles by this author Simon Conti More articles by this author Shan X. Wang More articles by this author joseph C. Liao More articles by this author Expand All Advertisement PDF downloadLoading ...

A nomogram for predicting the risk of residual stone fragments after ureteroscopy.

The residual stone fragment is a tremendous issue after ureteroscopic lithotripsy and requires urologists to evaluate the condition of patients comprehensively. Our study aimed to construct a nomogram to make a personalized prediction of postoperative residual stone rate (RSR). We implemented a retrospective cohort study in the Department of Urology, Shanghai General Hospital. A total of 277 patients undergoing ureteroscopy (URS) were enrolled in our study. Among them, 186 patients were included in the training group and the remaining 91 patients comprised the testing group. We utilized stepwise forward algorithm and logistic regression analysis to build predictive models and selected the best model based on Akaike's information criterion (AIC). The model was assessed by receiver operating characteristic (ROC) curves and the Hosmer-Lemeshow (HL) test. We also conducted decision curve analysis (DCA) to demonstrate the net benefit of the model. The independent testing group was used to validate the practicability of the nomogram. The severity of hydronephrosis, stone location, the transverse diameter of stone, hypertension, and white blood cell (WBC) were found to be significant predictive variables for RSR after URS. The area under the curve (AUC) of the training group was 0.7203 and that of the testing group was 0.7280. Besides, the nomogram also presented great calibration and accepted net benefit in a wide range of probabilities. Our study achieved a predictive nomogram with excellent application value for urologists to assess RSR and make personalized treatment decisions.

Factors Affecting the Outcome of Extracorporeal Shockwave Lithotripsy in Urinary Stone Treatment

Background and aim: The recurrence of urinary stones occurs in two thirds of patients within a 20-year period, making urinary stones a common pathology. Among urology pathologies, kidney stones rank third behind urinary infections and conditions of the prostate. The present study intended to assess various factors affecting the extracorporeal shockwave lithotripsy (ESWL) outcome in urinary stone treatment. Methods: This cross-sectional study was carried out on 136 urinary stone patients who underwent extracorporeal shockwave lithotripsy in the Department of Urology, Sahiwal Teaching Hospital, Sahiwal for the duration from September 2021 to August 2022. Computed tomography confirmed the presence of stones and measured the size (3-20 mm), distance from skin to stone, location, and density in Hounsfield units. Patient’s characteristics such as estimated rate of glomerular filtration and BMI were measured. A successful ESWL requires at least a 3mm residual renal stone fragment in post-therapy, and at least a complete clearance of ureteric stones at the end of treatment. SPSS version 26 was used for descriptive statistic. Results: Of the total 136 urinary stone patients, there were 108 (79.4%) male and 28 (20.6%) females. The incidence of stones present in proximal ureter, mid, and distal ureter was 72 (52.9%), 7 (5.1%), and 57 (41.9%) respectively. All the patients underwent ESWL 1.5 times (average), and the success rate in first, second, and third session was 67.8% (n=92), 83.8% (n=114), and 91.2% (n=124) respectively. The overall success rate of ESWL was 80.9%. A multivariate analysis revealed that HU [OR=0.89, 95% CI, 0.96-0.98, P=0.001) and stone size [OR=0.79, 95% CI, 0.62-0.98, P=0.051] were significantly affecting the first ESWL session success rate. Third session success rate was significantly affected by stone size [OR=0.76, 95% CI, 0.58-0.95, P=0.015]. Stent associated higher failure rate [OR=6.425, 95% CI, 2.132-18.235, p=0.001] and ESWL failure was three-times higher in females than in male. Conclusion: The present study found that the overall success rate of ESWL in urinary stone treatment was 80.9%. ESWL success rates were affected by stone size and HU. Patients' pain and fragmentation levels should be considered when adjusting the intensity of ESWL. Keywords: Urinary stone treatment, Outcomes, Extracorporeal shockwave lithotripsy