The Efficacy and Safety of Radiation-Free Retrograde Intrarenal Surgery: A Prospective Multicenter-Based, Randomized, Controlled Trial.

PURPOSE: Fluoroscopy is usually required during retrograde intrarenal surgery (RIRS). Although fluoroscopy is considered necessary for effective and safe RIRS, there is growing awareness regarding radiation exposure risk to patients and surgeons. We conducted a multicenter-based, randomized, controlled trial to compare the safety and effectiveness of radiation-free (RF) RIRS with radiation-usage (RU) RIRS for kidney stone management. MATERIALS AND METHODS: From August 2020 to April 2022, patients with a unilateral kidney stone (≤20 mm) eligible for RIRS were prospectively enrolled in 5 tertiary medical centers after randomization and divided into the RF and RU groups. RIRS was performed using a flexible ureteroscope with a holmium:YAG laser. The primary end point of this study was the success rate, defined as complete stone-free or residual fragments with asymptomatic kidney stones ≤ 3 mm. The secondary end point of this study was ascertaining the safety of RF RIRS. The success rates were analyzed using a noninferiority test. RESULTS: Of the 140 consecutive randomized participants, 128 patients completed this study (RF: 63; RU: 65). The success rates (78% vs 80%, P = .8) were not significantly different between the groups. The rate of high-grade (grade 2-4) ureter injury was not significantly higher in the RF group compared to the RU group (RF = 3 [4.8%] vs RU = 2 [3.1%], P = .6). In RF RIRS, the success rate was noninferior compared to RU RIRS (the difference was 2.2% [95% CI, 0.16-0.12]). CONCLUSIONS: This study demonstrated that the surgical outcomes of RF RIRS were noninferior to RU RIRS.

STONE Score: A Predictor for Need of Blood Transfusion in Percutaneous Nephrolithotomy.

OBJECTIVE: To determine if the STONE score is a predictor of blood transfusion and if patient-related factors, i.e., the presence of comorbidities such as urinary tract infection and obesity, can predict blood transfusion post-percutaneous nephrolithotomy. STUDY DESIGN:  A cross-sectional descriptive study.  Place and Duration of the Study: Department of Urology, The Aga Khan University Hospital, Karachi, Pakistan, between March 2022 and 2023. METHODOLOGY: All patients admitted for percutaneous nephrolithotomy (PNCL) were included in the study. STONE score and patient related factors were assessed. Chi-square or Fisher's exact test was applied to check the association between the dependent variables (blood transfusion) and the independent variables. Logistic regression analysis was applied to compare the variables responsible for the outcome.  Results: During the study period, 150 patients underwent PCNL. After exclusion, 89 patients were included in the study. The mean STONE score was 7.87, and the total number of transfusions was 8 (8.9%). BMI (body mass index) >25kg/m2 and STONE score were found to be significant factors predicting the need for transfusion with p-values of 0.02 and 0.03, respectively. On multivariate analysis, only BMI was found to be a significant contributing factor for blood transfusion. CONCLUSION:  High BMI and STONE score are significant predictive factors for blood transfusion post-PCNL. Blood product arrangements should be restricted to obese patients. KEY WORDS: STONE score, Body mass index, Blood transfusion.

RETROGRADE INTRARENAL LITHOTRIPSY USING DISPOSABLE FLEXIBLE URETEROSCOPE.

This research aims to characterize efficiency of a flexible ureteroscope that is of single use with regard to surgical time, absence of stone, and complications. From March 2022 to April 2023, the Basrah Urological Centre carried out this anticipated work. After excluding patients with untreated urinary tract infections, excessive blood urea, and ureteral strictures, the study involved ninety-eight patients. All patients were above 20 years of age. Patients were operated on by the same surgeon. This study involved 108 patients in this study composed of 42 (39.8%) men and 65 (60.2%) women. With a standard deviation of 10.9 years, the patient's mean age was 39.2 years. The total stone burden ranged from 6.9 to 14.5 mm, averaging 9.7±2.9 mm. The stone density ranged from 820-1411 HU, averaging 1000.8±279.3 HU. According to the current study, treating renal stones with a single-use flexible ureteroscope is less complicated and more successful.

Rigid ureteroscopic lithotripsy with a pressure-controlling ureteral access sheath for complex steinstrasse.

OBJECTIVE: To evaluate the safety and efficacy of rigid ureteroscopic lithotripsy with a pressure-controlling ureteral access sheath (PC-UAS) for complex steinstrasse. METHODS: Thirty-one consecutive patients (male: 18; female: 13) with steinstrasse were enrolled, six of whom had concurrent kidney stones. The mean cumulative stone size was 2.7 ± 1.3 cm. The patients were treated with rigid ureteroscopic lithotripsy using a PC-UAS. The cavity pressure parameters were set as follows: control value at -15 mmHg to -2 mmHg, warning value at 20 mmHg, and limit value at 30 mmHg. The infusion flow rate was set at 150-200 ml/min. A holmium laser (550 µm) was used to powderize the stone at 2.0-2.5 J/pulse with a frequency of 20-30 pulses/s. Analyses included cavity pressure, operative time, stone-free rates, and complications. RESULTS: Among the 31 patients, 29 were successfully treated with PC-UAS, with nine requiring adjunctive flexible ureteroscopy for stone migration to the kidney. Two procedures were converted to percutaneous nephrolithotomies due to failure of sheath placement. The cavity pressure of all 29 patients was well-maintained below 20 mmHg, with clear vision. The mean operative time was 48.2 ± 17.7 min. No complications, such as ureteral perforation, mucosal avulsion, or hemorrhage, occurred. Two cases of Clavien-Dindo grade I complications occurred. No major complications (Clavien-Dindo grade II-V) occurred. The mean postoperative hospitalization time was 1.7 days. The stone-free rates 1 day and 1 month after surgery were 93.1% and 96.6%, respectively. One patient with residual stones underwent extracorporeal shockwaves. CONCLUSIONS: Rigid ureteroscopic lithotripsy with PC-UAS can effectively control the cavity pressure, shorten the operation time, and improve the efficiency of broken stones, thus reducing the complication rate.

A machine learning approach using stone volume to predict stone-free status at ureteroscopy.

INTRODUCTION: To develop a predictive model incorporating stone volume along with other clinical and radiological factors to predict stone-free (SF) status at ureteroscopy (URS). MATERIAL AND METHODS: Retrospective analysis of patients undergoing URS for kidney stone disease at our institution from 2012 to 2021. SF status was defined as stone fragments < 2 mm at the end of the procedure confirmed endoscopically and no evidence of stone fragments > 2 mm at XR KUB or US KUB at 3 months follow up. We specifically included all non-SF patients to optimise our algorithm for identifying instances with residual stone burden. SF patients were also randomly sampled over the same time period to ensure a more balanced dataset for ML prediction. Stone volumes were measured using preprocedural CT and combined with 19 other clinical and radiological factors. A bagged trees machine learning model with cross-validation was used for this analysis. RESULTS: 330 patients were included (SF: n = 276, not SF: n = 54, mean age 59.5 ± 16.1 years). A fivefold cross validated RUSboosted trees model has an accuracy of 74.5% and AUC of 0.82. The model sensitivity and specificity were 75% and 72.2% respectively. Variable importance analysis identified total stone volume (17.7% of total importance), operation time (14.3%), age (12.9%) and stone composition (10.9%) as important factors in predicting non-SF patients. Single and cumulative stone size which are commonly used in current practice to guide management, only represented 9.4% and 4.7% of total importance, respectively. CONCLUSION: Machine learning can be used to predict patients that will be SF at the time of URS. Total stone volume appears to be more important than stone size in predicting SF status. Our findings could be used to optimise patient counselling and highlight an increasing role of stone volume to guide endourological practice and future guidelines.

Evaluating the Safety of Retrograde Intrarenal Surgery (RIRS): Intra- and Early Postoperative Complications in Patients Enrolled in the Global Multicentre Flexible Ureteroscopy Outcome Registry (FLEXOR).

PURPOSE: To assess the incidence of the most common intra- and early postoperative complications following RIRS in a large series of patients with kidney stones. METHODS: We conducted a retrospective analysis of patients with kidney stones who underwent RIRS across 21 centers from January 2018 to August 2021, as part of the Global Multicenter Flexible Ureteroscopy Outcome (FLEXOR) Registry. RESULTS: Among 6669 patients undergoing RIRS, 4.5% experienced intraoperative pelvicalyceal system bleeding without necessitating blood transfusion. Only 0.1% of patients, required a blood transfusion. The second most frequent intraoperative complication was ureteric injury due to the ureteral access sheath requiring stenting (1.8% of patients). Postoperatively, the most prevalent early complications were fever/infections requiring antibiotics (6.3%), blood transfusions (5.5%), and sepsis necessitating intensive care unit admission (1.3%). In cases of ureteric injury, a notably higher percentage of patients exhibited multiple stones and stone(s) in the lower pole, and these cases were correlated with prolonged lasing and overall surgical time. Hematuria requiring a blood transfusion was associated with an increased prevalence of larger median maximum stone diameters, particularly among patients with stones exceeding 20 mm. Furthermore, these cases exhibited a significant prolongation in surgical time. Sepsis necessitating admission to the intensive care unit was more prevalent among the elderly, concomitant with a significantly larger median maximum stone diameter. CONCLUSIONS: Our analysis showed that RIRS has a good safety profile but bleeding requiring transfusions, ureteric injury, fever, and sepsis are still the most common complications despite advancements in technology.

Fluid absorption during flexible ureteroscopy with intelligent control of renal pelvic pressure: a randomized controlled trial.

PURPOSE: To investigate fluid absorption and its influencing factors during flexible ureteroscopy with intelligent control of renal pelvic pressure (RPP). METHODS: A total of 80 patients with upper urinary tract calculi underwent flexible ureteroscopy with intelligent control of RPP by pressure-measuring ureteral access sheath and were randomly divided into four groups. The RPP of Groups A, B, and C were set at - 5, 0 and 5 mmHg, respectively. Conventional flexible ureteroscopy with uncontrolled pressure served as control Group D. The perfusion flow rate was set at 100 ml/min in the four groups, with 20 patients in each group. The fluid absorption was measured by 1% ethanol every 10 min. Operation time, stone-free rate, and complications were recorded. RESULT: Seventy-three patients were finally included in the RCT. The general and preoperative data of the patients were comparable between the groups. The fluid absorption of Groups A, B, and C was significantly less than that of Group D (P < 0.01). Fluid absorption and operation time were positively correlated, and the correlation coefficients R were 0.864, 0.896, 0.918, and 0.947, respectively (P < 0.01). The fluid absorption of patients with vomiting, fever and ureteral injury was greater than that of patients without complications in the four groups (P < 0.01). In different groups, fluid absorption was greater in patients with ureteral injury Post-Ureteroscopic Lesion Scale (PULS) 1-3 than in noninjured patients (P < 0.01). CONCLUSION: Flexible ureteroscopy with intelligent control of RPP effectively reduces the absorption of perfusion fluid. Operation time and ureteral injury are also key factors affecting perfusion fluid absorption. REGISTRATION NUMBER AND DATE: NCT05201599; August 11, 2021.

Utility of the modified 5-item frailty index as a predictor of postoperative febrile urinary tract infection in patients who underwent ureteroscopy with laser lithotripsy.

PURPOSE: This study aimed to assess the effect of the modified 5-item frailty index on perioperative complications and surgical outcomes in patients who underwent ureteroscopy with laser lithotripsy for upper urinary tract stones. METHODS: Patients who underwent ureteroscopy with laser lithotripsy for upper urinary tract stones between 2019 and 2022 were reviewed retrospectively. Assessment was performed using the modified 5-item frailty index based on medical history (hypertension, diabetes, heart failure, chronic obstructive pulmonary disease) and functional status. Patients were categorized into the high (≥ 2) and low (≤ 1) modified 5-item frailty index groups based on the frailty score. We compared the perioperative complications and surgical outcomes between the two groups. RESULTS: Seventy-one (15.8%) and 393 (84.1%) of the 467 patients were classified into the high and low modified 5-item frailty index groups, respectively. The high modified 5-item frailty index group exhibited a significant association with increased febrile urinary tract infections compared to the low modified 5-item frailty index group [≥ 37.8 °C: 15 (20.3%) vs 13 (3.3%), p < 0.001; ≥ 38 °C: 9 (12.2%) vs 7 (1.8%), p < 0.001]. Surgical outcomes, including operative time and stone-free rate, did not differ significantly between the two groups. CONCLUSION: The modified 5-item frailty index is valuable for predicting postoperative complications, particularly febrile urinary tract infections, after ureteroscopy with laser lithotripsy for upper urinary tract stones. This index allows for practical preoperative risk assessment in patients who underwent ureteroscopy with laser lithotripsy.

The relationship between stone-free and patient position in retrograde intrarenal surgery: a randomized prospective study.

PURPOSE: Residual fragments not removed with urinary stone surgery may become symptomatic. In this context, this study was carried out to investigate the effect of performing retrograde intrarenal surgery, which is conventionally performed in the lithotomy position, in the modified lithotomy position (Trend-side) on stone-free rates following the surgery. METHODS: This prospective study consisted of 100 patients with a single kidney stone smaller than 2 cm between 2021 and 2023. These patients were randomized into two groups of 50 patients each to be operated on in the conventional lithotomy and Trend-side positions. Variables were compared using independent t test for continuous variables and chi-square test for categorical variables. RESULTS: There was no significant difference between the lithotomy and Trend-side position groups in terms of preoperative size, density, location of the stone, and hydronephrosis degree. Stone-free rate was 72% (n = 36) in the lithotomy group and 92% (n = 46) in the Trend-side group. Hence, there was a significant difference between the groups in the stone-free rate in favor of the Trend-side group (p = 0.009). Fragmentation time was statistically significantly shorter in the Trend-side group than in the lithotomy group (34 ± 17 min vs. 43 ± 14 min; p = 0.006). There was no significant difference between the groups in postoperative complication rates. CONCLUSION: Performing retrograde intrarenal surgery in the Trend-side position shortened the duration of fragmentation compared to the lithotomy position and was associated with higher stone-free rates. In conclusion, the Trend-side position can be safely preferred in patients undergoing retrograde intrarenal surgery due to kidney stones.

Stone decision engine accurately predicts stone removal and treatment complications for shock wave lithotripsy and laser ureterorenoscopy patients.

Kidney stones form when mineral salts crystallize in the urinary tract. While most stones exit the body in the urine stream, some can block the ureteropelvic junction or ureters, leading to severe lower back pain, blood in the urine, vomiting, and painful urination. Imaging technologies, such as X-rays or ureterorenoscopy (URS), are typically used to detect kidney stones. Subsequently, these stones are fragmented into smaller pieces using shock wave lithotripsy (SWL) or laser URS. Both treatments yield subtly different patient outcomes. To predict successful stone removal and complication outcomes, Artificial Neural Network models were trained on 15,126 SWL and 2,116 URS patient records. These records include patient metrics like Body Mass Index and age, as well as treatment outcomes obtained using various medical instruments and healthcare professionals. Due to the low number of outcome failures in the data (e.g., treatment complications), Nearest Neighbor and Synthetic Minority Oversampling Technique (SMOTE) models were implemented to improve prediction accuracies. To reduce noise in the predictions, ensemble modeling was employed. The average prediction accuracies based on Confusion Matrices for SWL stone removal and treatment complications were 84.8% and 95.0%, respectively, while those for URS were 89.0% and 92.2%, respectively. The average prediction accuracies for SWL based on Area-Under-the-Curve were 74.7% and 62.9%, respectively, while those for URS were 77.2% and 78.9%, respectively. Taken together, the approach yielded moderate to high accurate predictions, regardless of treatment or outcome. These models were incorporated into a Stone Decision Engine web application (http://peteranoble.com/webapps.html) that suggests the best interventions to healthcare providers based on individual patient metrics.

Exploring the impact of digital health literacy on quality of life in patients undergoing retrograde intrarenal surgery for kidney stone treatment: a prospective, single-center study.

Retrograde intrarenal surgery (RIRS) is the recommended treatment for renal stones up to two cm in size. As digital health literacy (e-HL) has become increasingly important in promoting informed health decisions and healthy behaviors, it is necessary to investigate its impact on RIRS treatment outcomes. We aimed to explore the influence of patients' e-HL level on their postoperative quality of life (QoL). We conducted an observational prospective study of 111 patients who underwent RIRS for renal pelvis stones. Before RIRS, we evaluated patients' e-HL using the electronic health literacy scale (eHEALS). QoL was evaluated using the five-level EuroQol five-dimensional questionnaire (EQ-5D-5L) one month after RIRS. SFR was determined by a negative CT scan or asymptomatic patients with stone fragments < 3 mm. Adult individuals aged 18 years or older with typical calyceal anatomy met the eligibility criteria for enrollment. Exclusion criteria for the study included patients with ureteric stones, anomalous kidneys, or bilateral renal stones. The relationship between patients' QoL and stone-free rate was explored using Spearman's rank correlation coefficient. The mean stone burden was 14 ± 3 mm (6-19 mm). The overall SFR was 83.3% after one month. The median EQ-5D-5L utility index and VAS score were 0.826 (0.41-1) and 70 (20-100) respectively, for the overall population. We found that poorer e-HL was associated with being older (p = 0.035), having less education (p = 0.005), and not having access to the internet (p < 0.001). A significant difference was observed between patients with sufficient e-HL and patients with limited e-HL in the self-care (p = 0.02) and anxiety/depression (p = 0.021) dimensions. To date, no study has examined the impact of patients' e-HL levels on postoperative QoL in patients undergoing RIRS. This study also revealed that e-HL levels in patients undergoing RIRS were related to postoperative QoL, especially self-care and anxiety/depression dimensions, whereas there was no relationship between them and SFR.

Needle-perc-assisted endoscopic surgery versus retrograde intrarenal surgery for the treatment of 1- to 2-cm lower-pole renal stones in patients with unfavorable infundibulopelvic anatomy: a matched-pair analysis.

PURPOSE: To compare the safety and efficacy of needle-perc-assisted endoscopic surgery (NAES) and retrograde intrarenal surgery (RIRS) for the treatment of 1- to 2-cm lower-pole stones (LPS) in patients with complex infundibulopelvic anatomy. METHODS: Between June 2020 and July 2022, 32 patients with 1- to 2-cm LPS and unfavorable lower-pole anatomy for flexible ureteroscopy were treated with NAES. The outcomes of these patients were compared with patients who underwent RIRS using matched-pair analysis (1:1 scenario). The matching parameters such as age, gender, body mass index, stone size, hardness, and pelvicalyceal anatomy characteristics including infundibular pelvic angle, infundibular length, and width were recorded. Data were analyzed using the Student's t-test, Mann-Whitney U test, and Fisher's exact test. RESULTS: The two groups had similar baseline characteristics and lower-pole anatomy. The stone burden was comparable between both groups. NASE achieved a significantly better initial stone-free rate (SFR) than RIRS (87.5% vs 62.5%, p = 0.04). The auxiliary rates for the NAES and RIRS groups were 12.5% and 31.3%, respectively (p = 0.13). Finally, the SFR after 1 month follow-up period was still higher for the NAES group than RIRS group (93.8% versus 81.3%), but the difference was not statistically significant (p = 0.26). Concerning the operation duration, overall complication rates, and postoperative hospital stay, there were no differences between two groups. CONCLUSION: Compared to RIRS for treating 1- to 2-cm LPS in patients with unfavorable infundibulopelvic anatomy for flexible ureteroscopy, NAES was safe and effective with higher SFR and similar complication rate.

Ultrasound-guided renal puncture followed by endoscopically guided tract dilatation vs standard fluoroscopy-guided percutaneous nephrolithotomy for non-opaque renal stones; a randomized clinical trial.

This study was designed to evaluate the non-inferiority of ultrasound puncture followed by endoscopically guided tract dilatation compared to the standard fluoroscopy-guided PCNL. Forty patients with non-opaque kidney stones eligible for PCNL were randomly divided into two groups. The standard fluoroscopy-guided PCNL using the Amplatz dilator was performed in the XRAY group. In the SONO group, the Kidney was punctured under an ultrasound guide followed by tract dilatation using a combination of the Amplatz dilator based on the tract length and an endoscopically guided tract dilatation using a bi-prong forceps in cases of short-advancement. The primary outcome was successful access. In 90% of cases in the XRAY and 95% in the SONO group access dilatation process was performed uneventfully at the first attempt (p = 0.5). In 45% of cases in the SONO group, bi-prong forceps were used as salvage for short-advancement. In one case in the X-ray group over-advancement occurred. One month after surgery, the stone-free rate on the CT-scan was 75% for the X-ray group and 85% for the SONO group (p = 0.4). There were no significant differences in operation time, hospitalization duration, transfusion, or complication rates between the two groups. We conclude that ultrasound-guided renal puncture, followed by endoscopically guided tract dilatation can achieve a high success rate similar to X-ray-guided PCNL while avoiding the harmful effects of radiation exposure and the risk of over-advancement.

Comparison of supine-prone percutaneous nephrolithotomy methods in the treatment of kidney stones in pediatric patients: prospective randomized study.

Mini-PCNL is one of the most effective surgical methods in the treatment of kidney stones in pediatric patients. In this study, we aimed to compare PCNL in the supine-prone position in pediatric patients (especially operation time, postop complications, hospital stay and stone-free rates).We conducted our study in a randomized and prospective manner. Patients with lower pole stones larger than 1 cm, stones larger than 1.5 cm in the pelvis, upper pole, midpole or multiple locations, and patients who did not respond to ESWL or whose family that preferred mini-PCNL to be the primary treatment were included in the study. Patients with any previous kidney stone surgery, patients with coagulation disorders and patients with retrorenal colon were excluded from the study. Between 2021 and 2023, a total of 144 patients underwent PCNL. 68 of these patients had supine PCNL and 76 prone PCNL. Postoperative Clavien grade1 complication occurred in a total of 7 patients in the prone position; Clavien grade1 complication occurred in 1 patient in the supine position. The mean operation time for prone PCNL was 119.88 ± 28.32 min, and the mean operative time for supine PCNL was 98.12 ± 14.97 the mean hospitalization time in prone PCNL was 3.56 ± 1.12 days, and 3.00 ± 0.85 days in supine PCNL. In conclusion, supine PCNL is a safe and effective method in the treatment of pediatric kidney stones and postoperative complications were observed to be less; the operation time and hospital stay were shorter in supine PCNL.

The safety and efficacy of Sotn ureteroscopy for renal and upper ureteral calculi: a prospective multicenter randomized controlled trial.

BACKGROUND: Sotn ureteroscopy is a new lithotripsy procedure developed on the basis of ureteroscopy and includes a rigid ureteral access sheath, standard mirror, lithotripsy mirror, and Sotn perfusion aspirator. Thus, we performed a prospective multicenter randomized controlled trial comparing the safety and efficacy of Sotn ureteroscopy in the treatment of renal and upper ureteral calculi. METHODS: In this study, 224 patients with renal and upper ureteral calculi were randomly divided equally into study and control groups from March 2018 to March 2022. All the patients were approved by the hospital ethics committee (proof number: ZF-2018-164-01 and ZF-2018-165-01) of the Second Affiliate Hospital of Guangzhou University of Chinese Medicine in China. The primary outcome was stone-free rate (SFR) assessed by computed tomography on the 1st day and month after treatment and operation duration. The secondary outcome was postoperative complication rate. RESULTS: In total, for upper ureteral calculi, the SFR of 1 day after operation of the Sotn ureteroscopy group was significantly higher than the rigid ureteroscopy group (83.6% vs. 60%, P=0.006). Moreover, operative time (33.7±1.80 vs. 52.9±2.73 min, P<0.005) of the Sotn ureteroscopy group was significantly lower than the rigid ureteroscopy group. Additionally, the SFR of 1 day after operation and operative time for the study group (Sotn ureteroscopy combined with flexible ureteroscopy) and the control group (flexible ureteroscopy alone) were 63.2% and 36.8% (P=0.005), 65.6±4.06 and 80.3±4.91 (P=0.023), respectively. However, there were no significant differences in the SFR of 1 month after operation, success rate of ureteral access sheath placement, and postoperative complications between the two groups (P>0.05). In subgroups with stone diameters ≥1.5 cm and stone CT values ≥1000 Hounsfield units, Sotn ureteroscopy showed more advantages in terms of the SFR of 1 day after operation. Importantly, complications such as ureteral injury, sepsis, fever, and severe hematuria were not statistically different between the two groups (P>0.05). CONCLUSIONS: For renal and upper ureteral calculi, Sotn ureteroscopy has the advantage of a higher SFR of 1 day after the operation and a shorter operative time, suggesting that the Sotn ureteroscopy may have further potential applications in clinics.

New infundibulopelvic angle measurement method can predict stone-free rates following retrograde intrarenal surgery.

To enhance the accuracy of predicting stone-free rates after retrograde intrarenal surgery, we devised a novel approach to assess the renal infundibulopelvic angle. We conducted a retrospective review of patient records for those who underwent retrograde intrarenal surgery for renal stones between April 2018 and August 2019. Patient demographics, stone characteristics, and perioperative data were recorded. Subsequently, we introduced a modified angle measurement called the pelvic stone angle and evaluated its predictive performance for stone-free rates by comparing it with the traditional method in scoring systems. A total of 43 individuals were included in this study. Notable differences in stone burden and Hounsfield unit measurements were found between stone-free and non-stone-free patients. The pelvic stone angle demonstrated a good model fit when used in scoring systems, performing equally well as the conventional approach. The area under the receiver operating characteristic curve for the R.I.R.S. scoring system using the pelvic stone angle and the conventional approach did not show a significant difference. In conclusion, the predictive ability of the pelvic stone angle for stone-free rates was comparable to the old measurement method. Moreover, scoring systems using the pelvic stone angle exhibited a better model fit than those using the conventional approach.

Efficacy of Flexible Ureteroscopy Lithotripsy and Percutaneous Nephrolithotomy in the Treatment of Patients with Kidney Stones and Their Impact on Inflammatory Response and Renal Function.

BACKGROUND: Kidney stones are one of the most common benign diseases in urology. As technology updates and iterates, more minimally invasive and laparoscopic surgeries with higher safety performance appear. This paper explores the effectiveness of retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) in treating kidney stones, focusing on their effects on inflammatory responses and renal function. METHODS: We conducted a retrospective analysis of 200 patients with kidney stones treated in our hospital between June 2019 and June 2023. 100 patients who underwent RIRS were included in the RIRS group. Another 100 patients who underwent PCNL treatment were included in the PCNL group. The intraoperative blood loss, operation duration, and hospitalization time of the two groups of patients were recorded and compared. The enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory factors in the serum of the two groups of patients: [serum amyloid A (SAA), interleukin-6 (IL-6) and high-sensitivity C-reactive protein (CRP)] and renal function index [blood urea nitrogen (BUN), creatinine (Scr) and serum cystatin (Cys-c)]. The two groups of patients were recorded separately: Postoperative complications and stone-free rate. RESULTS: Operation duration was longer for the RIRS group than the PCNL group, which exhibited significantly less intraoperative blood loss and shorter hospital stays (p < 0.05). Before surgery, there was no statistically significant difference in the serum levels of SAA, IL-6, and CRP between the two groups of patients (p > 0.05). On the first day after surgery, the serum SAA levels in both groups were lower than before surgery, IL-6 and CRP levels were higher than before surgery, and the serum levels of SAA, IL-6, and CRP in the RIRS group were significantly lower than those in the PCNL group. The difference was statistically significant (p < 0.05). Before surgery, there was no statistically significant difference in the serum BUN, Scr, and Cys-c levels between the two groups of patients (p > 0.05). On the first day after surgery, the serum BUN, Scr, and Cys-c levels of the two groups of patients were significantly higher than those before surgery. The serum BUN, Scr, and Cys-c levels of the RIRS group were significantly lower than those of the PCNL group, and the difference was statistically significant (p < 0.05). Both surgical methods have sound stone-clearing effects regarding long-term stone clearance rates 1 month and 3 months after surgery (p > 0.05). PCNL had a better stone clearance rate on the 2nd postoperative day (p < 0.05). The incidence of postoperative complications in the RIRS group was significantly lower than that in the PCNL group, and the difference was statistically significant (p < 0.05). CONCLUSION: For kidney stones ≤2 cm, PCNL showed higher stone clearance rates on the second postoperative day. However, RIRS and PCNL demonstrated adequate long-term stone clearance at 1 and 3 months post-surgery. Both surgical methods are safe and effective, and RIRS is safer than PCNL. Compared with PCNL, RIRS is a new method of kidney stone operation, which has less trauma to the patient's body and fewer complications after the operation, speeding up the recovery process of the patient.