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

Constructing a machine learning model for systemic infection after kidney stone surgery based on CT values

This study aims to develop a machine learning model utilizing Computed Tomography (CT) values to predict systemic inflammatory response syndrome (SIRS) after endoscopic surgery for kidney stones. The goal is to identify high-risk patients early and provide valuable guidance for urologists in the early diagnosis and intervention of post-operative urosepsis. This study included 833 patients who underwent retrograde intrarenal surgery (RIRS) or percutaneous nephrolithotomy (PCNL) for kidney stones. Five machine learning algorithms and ten preoperative or intraoperative variables were used to develop a predictive model for SIRS. The SHapley Additive exPlanations (SHAP) method was used to explain the distribution of feature importance in the model's predictions. Among the 833 patients, 126 (15.1%) developed SIRS postoperatively. All five machine learning models demonstrated strong discrimination on the validation set (AUC: 0.690-0.858). The eXtreme Gradient Boosting (XGBoost) model was the best performer [AUC: 0.858; sensitivity: 0.877; specificity: 0.981; accuracy: 0.841; positive predictive value: 0.629; negative predictive value: 0.851]. The characteristic importance of the Machine Learning model (ML model) and SHAP results indicated Hounsfield Unit (HU), Urinary protein, Stone burden, and Serum uric acid as important predictors for the model. A machine learning model utilizing CT values was developed to predict postoperative SIRS in endoscopic kidney stone surgery. The model demonstrates strong predictive performance and can assist in assessing the risk of urosepsis in postoperative patients.

A novel infrared spectroscopy marker for assessing the postoperative infection risk in patients with upper urinary tract calculus

The aim of this study is to evaluate the ability of infrared wavenumber of calculus to predict postoperative infection in patients with upper urinary tract calculus (UUTC), and to establish a predictive model based on this. From March 2018 to March 2023, 480 UUTC patients from Fujian Provincial Hospital were included in this study. The infrared-wavenumbers related infection score (IR-infection score) was constructed by univariate analysis, multicollinearity screening, and Lasso analysis to predict postoperative infection. Continually, the Delong test was used to compare the predictive power between the IR-infection score and traditional indicators. Afterward, we performed urine metagene sequencing and stone culture to prove the correlation between calculus toxicity and IR-infection score. Finally, logistic regression was used to build a nomogram. IR-infection score composed of four independent wavenumbers could precisely predict postoperative infection (AUCvalidation cohort = 0.707) and sepsis (AUCvalidation cohort = 0.824). IR-infection score had better predictive ability than commonly used clinical indicators. Moreover, metagenomics sequencing and calculus culture confirmed the correlation between IR-infection score and calculus toxicity (all P < 0.05). The nomogram based on the IR-infection score had high predictive power (all AUCs > 0.803). Our study first developed a novel infrared spectroscopy marker and nomogram, which can help urologists better predict postoperative infection in UUTC patients.

Scoping Review of Experimental and Clinical Evidence and Its Influence on Development of the Suction Ureteral Access Sheath

The ureteral access sheath (UAS) has been a boon and a bane in flexible ureteroscopy (FURS), with its merits and demerits well established. Its design and dimensions were instrumental in reshaping the way flexible scopes were used and were key adjuncts to establishing retrograde intrarenal surgery (RIRS) as a standard of care in the endourological management of renal stones. With the ever-changing landscape of RIRS over the decades shaped by technological advancements in lasers and flexible scopes, the UAS has also continuously evolved. The utility of suction in endourology has recently changed the way RIRS is performed and is a game changer for FURS outcomes. With strong clinical and experimental evidence to support its use, the UAS has undergone a transformative change in the recent past, with its ability to monitor intrarenal pressure and provide a superior vacuum-cleaner effect that improves the trifecta of RIRS, namely an improved single-stage stone-free rate (SFR), minimise complications, and reduce reinterventions. Our comprehensive review outlines the key clinical and experimental evidence and traces the developments that were key to modifying the traditional UAS into a flexible and navigable suction ureteric access sheath (FANS) and highlights how the design and modifications, in turn, influence the ability to push the boundaries of RIRS.

Efficacy of Aspiration-Assisted Ureteral Access Sheath (ClearPETRA) in Retrograde Intrarenal Surgery

Backgrounds: In the renal intrarenal stone surgery (RIRS) procedure, ureteral access sheath (UAS) is still used in the majority of surgeries to both protect the flexible ureteroscope (FURS) and reduce intrarenal pressure. ClearPETRA is a new UAS that has an integrated aspiration port. We aimed to evaluate the clinical outcomes and effectiveness of Aspiration-Assisted UAS (ClearPETRA) in the RIRS procedure. Methods: One thousand six hundred twenty patients who underwent RIRS between January 2021 and January 2024 were evaluated retrospectively and 512 patients were included in the study. According to stone size, patients with stones less than 2 cm and those with stones between 2 and 3 cm were analyzed separately. Patient's demographic data, stone size, body mass index, Extracoporeal Shockwave Lithotripsy (ESWL) history, stone side, stone density (Hounsfield Unit), operation time, stone-free rate (SFR), and the number of patients with sepsis were recorded. SFR was evaluated with kidney urinary bladder 3 months after surgery for opaque calculi. Nonopaque calculi patients were evaluated with noncontrast computed tomography 3 months after surgery. In the postoperative evaluation, patients with stones less than 4 mm were evaluated as SFR. P value of <0.01 was considered statistically significant. Results: Patient's demographic data, stone characteristics, and history of ESWL were similar in the ClearPETRA and UAS groups (P > .05). A total of 328 patients who underwent RIRS for stones less than 2 cm were included (80 ClearPETRA, 248 UAS). Length of hospital stay, operation time, SFR, secondary intervention, or postoperative sepsis (P ≥ .01) were similar in both groups. The incidence of postoperative fever was statistically significantly lower in the ClearPETRA group (P = .006). A total of 184 patients who underwent RIRS for stones between 2 and 3 cm were included (42 ClearPETRA, 142 UAS). In the ClearPETRA group, operation time was statistically significantly shorter (P = .002), SFR was statistically significantly higher (P = .003), and the number of fever and sepsis were statistically significantly less (P = .003 and 0.002, respectively). Conclusion: We found that ClearPETRA reduces the likelihood of postoperative fever after RIRS surgeries. Moreover, we can say that the use of ClearPETRA in RIRS, especially for stones larger than 2 cm, reduces the operation time, increases the SFR, and also reduces sepsis rates.

Percutaneous nephrolithotomy in patients with incidental encountered purulent urine at initial puncture

We are reporting the 39 patients' outcomes who underwent percutaneous nephrolithotomy and purulent urine encountered at the initial steps of surgery. Of 873 patients who underwent PCNL, 48 had purulent fluid during the initial puncture. After excluding those at risk for infection, we studied 39 patients' preoperative and postoperative variables-including postoperative day (POD) 1, 3, 5 fevers. In group 1, 21 patients had a nephrostomy tube placed, and PCNL was postponed. In group 2, 18 patients had successful stone removal in the first session. All surgeries were successful, with no septic events during follow-up. No significant differences in preoperative variables were found. 14% and 22% of patients in groups 1 and 2 had infected fluid (p = 0.470). Four patients in group 1 (19%) and seven patients in group 2 (38.9%) had a high fever (≥ 38 C) on POD1 (p = 0.171), and 1 (5%) in group 1 and 3 (17%) in group 2 had high fever on POD 3 (p = 0.22). No patients remained with high fever on POD5. Mild sepsis was diagnosed in 9.5% of group 1 and 16% of group 2 (p = 0.820), and hospitalization time differed significantly (p < 0.001). Stone size and operation time were correlated with postoperative fever, and prolonged hospital stays were associated with positive blood cultures and postponed procedures. PCNL with proper technique and antibiotics can lead to quicker recovery and reduced hospitalization time in selected patients with pus in their pelvicalyceal system.

Percutaneous management of upper tract stones: from mini to maxi percutaneous nephrolithotomy

PURPOSE OF REVIEW

Percutaneous nephrolithotomy (PCNL) continues as the gold standard for the surgical management of large renal stones. This short review is intended to highlight recent publications on PCNL of all tract sizes, from mini to standard.

RECENT FINDINGS

Literature on PCNL in the last 2 years has focused on several main themes - decreasing complications, improving postoperative pain control, and new technology to improve outcomes. Mini-PCNL continues to prove effective and safe, with a new vacuum sheath showing promise of improving stone-free rates and decreasing infections. In terms of infections, preoperative midstream urine culture continues to be a poor indicator of postoperative infection. One of the biggest changes to PCNL practice is the reintroduction of tranexamic acid, which has shown to significantly decrease bleeding and improve outcomes. In terms of postoperative pain control, local blocks are effective and low risk.

SUMMARY

There are many options for surgeons when it comes to PCNL from sheath size to pain management to preoperative medication to decrease bleeding. Future research will continue to highlight, which advances are the most beneficial.

Randomized comparison of effect of standard antibiotic prophylaxis versus enhanced prophylactic measures on rate of urinary tract infection after flexible ureteroscopy

PURPOSE

To compare the rate of post-flexible ureteroscopy urinary tract infection (UTI) in patients subjected to the standard antibiotic prophylaxis alone versus enhanced prophylactic measures.

METHODS

A prospective randomized controlled study included 256 patients subjected to flexible ureteroscopy (FURS) for ureteral or renal stones from March 2018 to July 2022. Treatment groups included the standard antibiotic prophylaxis group (group 1, n=128) and the enhanced prophylaxis group (group 2, n=128). Patients in group 1 were injected with intravenous fluoroquinolone one hour preoperatively, and oral antibiotics were used for 24 h postoperatively. Patients in group 2 had urine culture ten days before the procedure; antibiotic-culture based was given for positive asymptomatic cases, while the procedure was deferred for active UTI.

RESULTS

The study groups were comparable regarding patient demographics, stone characteristics, operative time, and intraoperative complications. The overall hospitalization time was 1.68 ± 0.81 days. Postoperative, and overall complications were significantly higher in group 1 (15.6% vs. 6.3%, p = 0.04 and 26.6% vs. 17.2%, p = 0.047), respectively. Twenty patients (15.6 %) in the standard prophylaxis group were diagnosed with UTI in comparison to 8 patients (6.3 %) in the enhanced prophylaxis group (p = 0.047).

CONCLUSIONS

Urinary tract infection after FURS could be reduced significantly by utilizing the suggested enhanced prophylactic approach.

Risk of Sepsis in Retrograde Intrarenal Surgery: A Systematic Review of the Literature

Context

Objective

Evidence acquisition

Evidence synthesis

Conclusions

Patient summary