Management of urinary stones: state of the art and future perspectives by experts in stone disease.

AIM: To present state of the art on the management of urinary stones from a panel of globally recognized urolithiasis experts who met during the Experts in Stone Disease Congress in Valencia in January 2024. Options of treatment: The surgical treatment modalities of renal and ureteral stones are well defined by the guidelines of international societies, although for some index cases more alternative options are possible. For 1.5 cm renal stones, both m-PCNL and RIRS have proven to be valid treatment alternatives with comparable stone-free rates. The m-PCNL has proven to be more cost effective and requires a shorter operative time, while the RIRS has demonstrated lower morbidity in terms of blood loss and shorter recovery times. SWL has proven to be less effective at least for lower calyceal stones but has the highest safety profile. For a 6mm obstructing stone of the pelviureteric junction (PUJ) stone, SWL should be the first choice for a stone less than 1 cm, due to less invasiveness and lower risk of complications although it has a lower stone free-rate. RIRS has advantages in certain conditions such as anticoagulant treatment, obesity, or body deformity. Technical issues of the surgical procedures for stone removal: In patients receiving antithrombotic therapy, SWL, PCN and open surgery are at elevated risk of hemorrhage or perinephric hematoma. URS, is associated with less morbidity in these cases. An individualized combined evaluation of risks of bleeding and thromboembolism should determine the perioperative thromboprophylactic strategy. Pre-interventional urine culture and antibiotic therapy are mandatory although UTI treatment is becoming more challenging due to increasing resistance to routinely applied antibiotics. The use of an intrarenal urine culture and stone culture is recommended to adapt antibiotic therapy in case of postoperative infectious complications. Measurements of temperature and pressure during RIRS are vital for ensuring patient safety and optimizing surgical outcomes although techniques of measurements and methods for data analysis are still to be refined. Ureteral stents were improved by the development of new biomaterials, new coatings, and new stent designs. Topics of current research are the development of drug eluting and bioresorbable stents. Complications of endoscopic treatment: PCNL is considered the most invasive surgical option. Fever and sepsis were observed in 11 and 0.5% and need for transfusion and embolization for bleeding in 7 and 0.4%. Major complications, as colonic, splenic, liver, gall bladder and bowel injuries are quite rare but are associated with significant morbidity. Ureteroscopy causes less complications, although some of them can be severe. They depend on high pressure in the urinary tract (sepsis or renal bleeding) or application of excessive force to the urinary tract (ureteral avulsion or stricture). Diagnostic work up:  Genetic testing consents the diagnosis of monogenetic conditions causing stones. It should be carried out in children and in selected adults. In adults, monogenetic diseases can be diagnosed by systematic genetic testing in no more than 4%, when cystinuria, APRT deficiency, and xanthinuria are excluded. A reliable stone analysis by infrared spectroscopy or X-ray diffraction is mandatory and should be associated to examination of the stone under a stereomicroscope. The analysis of digital images of stones by deep convolutional neural networks in dry laboratory or during endoscopic examination could allow the classification of stones based on their color and texture. Scanning electron microscopy (SEM) in association with energy dispersive spectrometry (EDS) is another fundamental research tool for the study of kidney stones. The combination of metagenomic analysis using Next Generation Sequencing (NGS) techniques and the enhanced quantitative urine culture (EQUC) protocol can be used to evaluate the urobiome of renal stone formers. Twenty-four hour urine analysis has a place during patient evaluation together with repeated measurements of urinary pH with a digital pH meter. Urinary supersaturation is the most comprehensive physicochemical risk factor employed in urolithiasis research. Urinary macromolecules can act as both promoters or inhibitors of stone formation depending on the chemical composition of urine in which they are operating. At the moment, there are no clinical applications of macromolecules in stone management or prophylaxis. Patients should be evaluated for the association with systemic pathologies. PROPHYLAXIS: Personalized medicine and public health interventions are complementary to prevent stone recurrence. Personalized medicine addresses a small part of stone patients with a high risk of recurrence and systemic complications requiring specific dietary and pharmacological treatment to prevent stone recurrence and complications of associated systemic diseases. The more numerous subjects who form one or a few stones during their entire lifespan should be treated by modifications of diet and lifestyle. Primary prevention by public health interventions is advisable to reduce prevalence of stones in the general population. Renal stone formers at "high-risk" for recurrence need early diagnosis to start specific treatment. Stone analysis allows the identification of most "high-risk" patients forming non-calcium stones: infection stones (struvite), uric acid and urates, cystine and other rare stones (dihydroxyadenine, xanthine). Patients at "high-risk" forming calcium stones require a more difficult diagnosis by clinical and laboratory evaluation. Particularly, patients with cystinuria and primary hyperoxaluria should be actively searched. FUTURE RESEARCH: Application of Artificial Intelligence are promising for automated identification of ureteral stones on CT imaging, prediction of stone composition and 24-hour urinary risk factors by demographics and clinical parameters, assessment of stone composition by evaluation of endoscopic images and prediction of outcomes of stone treatments. The synergy between urologists, nephrologists, and scientists in basic kidney stone research will enhance the depth and breadth of investigations, leading to a more comprehensive understanding of kidney stone formation.

What are the Benefits and Harms of Ureteroscopy Compared with Shock-wave Lithotripsy in the Treatment of Upper Ureteral Stones? A Systematic Review.

CONTEXT: Extracorporeal shock wave lithotripsy (SWL) and ureteroscopy (URS), with or without intracorporeal lithotripsy, are the most common treatments for upper ureteric stones. With advances in technology, it is unclear which treatment is most effective and/or safest. OBJECTIVE: To systematically review literature reporting benefits and harms of SWL and URS in the management of upper ureteric stones. EVIDENCE ACQUISITION: Databases including Medline, Embase, and the Cochrane library were searched from January 2000 to November 2014. All randomised controlled trials (RCTs), quasi-randomised controlled trials, and nonrandomised studies comparing any subtype or variation of URS and SWL were included. The primary benefit outcome was stone-free rate (SFR). The primary harm outcome was complications. Secondary outcomes included retreatment rate, need for secondary, and/or adjunctive procedures. The Cochrane risk of bias tool was used to assess RCTs, and an extended version was used to assess nonrandomised studies. Grading of Recommendations Assessment, Development, and Evaluation was used to assess the quality of evidence. EVIDENCE SYNTHESIS: Five thousand-three hundred and eighty abstracts and 387 full-text articles were screened. Forty-seven studies met inclusion criteria; 19 (39.6%) were RCTs. No studies on children met inclusion criteria. URS and SWL were compared in 22 studies (4 RCTs, 1 quasi-randomised controlled trial, and 17 nonrandomised studies). Meta-analyses were inappropriate due to data heterogeneity. SFR favoured URS in 9/22 studies. Retreatment rates were higher for SWL compared with URS in all studies but one. Longer hospital stay and adjunctive procedures (most commonly the insertion of a JJ stent) were more common when primary treatment was URS. Complications were reported in 11 out of 22 studies. In eight studies, it was possible to report this as a Clavien-Dindo Grade. Higher complication rates across all grades were reported for URS compared with SWL. For intragroup (intra-SWL and intra-URS) comparative studies, 25 met the inclusion criteria. These studies varied greatly in outcomes measured with data being heterogeneous. CONCLUSIONS: Compared with SWL, URS was associated with a significantly greater SFR up to 4 wk but the difference was not significant at 3 mo in the included studies. URS was associated with fewer retreatments and need for secondary procedures, but with a higher need for adjunctive procedures, greater complication rates, and longer hospital stay. PATIENT SUMMARY: In this paper, the relative benefits and harms of the two most commonly offered treatment options for urinary stones located in the upper ureter were reviewed. We found that both treatments are safe and effective options that should be offered based on individual patient circumstances and preferences.

Xanthogranulomatous Pyelonephritis with Staghorn Calculus, Acute Gangrenous Appendicitis and Enterocolitis: A Multidisciplinary Challenge of Kidney-Preserving Conservative Therapy.

Xanthogranulomatous pyelonephritis (XP) is a rare form of pyelonephritis and without treatment destructive to the kidney. We describe a 74-year-old Caucasian immunocompetent female patient with XP and multiple abscesses on the upper pole of the right kidney and several impacted obstructing renal calculi in the middle calyx that developed severe colitis and gangrenous appendicitis during therapy. Proteus mirabilis was detected as the major pathogen in the urine culture. Kidney preserving therapy was carried out by intensive parenteral bacterial eradication, CT-guided abscess drainage and stone destruction by 3 sessions of extracorporeal shock wave lithotripsy under ureteral stenting. Large tumor masses in XP are often daunting and may lead to a nephrectomy. However, kidney-preserving therapy is possible and should be considered in non-septic patients or in case of a solitary kidney.