Effect of alkalized urine on renal calculi in patients with gout: a protocol for a placebo-controlled, double-blinded randomized controlled trial

Background The prevalence of renal calculi in patients with gout is high. Alkalized urine has been recommended by the 2020 European Association of Urology (EAU) guidelines to promote calculus dissolution. However, randomized controlled trials are lacking. Methods In the protocol of this randomized, placebo-controlled, double-blinded trial, patients with gout combined with renal calculi are randomized (1:1) to the placebo and sodium bicarbonate groups. The intervention would be performed for 24 weeks, the 1–12 weeks are double-blinded, and the 13–24 weeks are open-labeled. Sodium bicarbonate (1 g tid) will be performed for 24 weeks in the sodium bicarbonate group. The placebo will be performed for 12 weeks and not be performed from 13 weeks to 24 weeks in the placebo group. All subjects will be administered febuxostat (40 mg/day) for 24 weeks and receive concomitant anti-inflammatory prophylaxis therapy for 12 weeks. The primary outcome is the proportion of patients whose renal calculus volume will be reduced after 12 weeks of treatment. The secondary outcomes include the volume changes of renal calculi, uric acid changes, the proportion of patients with serum uric acid (sUA) levels < 360 μmol/L, the changes in estimated glomerular filtration rate (eGFR), the pH value of urine, and the incidence of adverse events after treatment for 12 and 24 weeks. Discussion This study will evaluate the efficacy and safety of sodium bicarbonate-alkalized urine on renal calculi in patients with gout. Trial registration ClinicalTrials.gov ChiCTR2100045183. Registered on April 7, 2021, with ChiCTR.

Perioperative Outcomes of Percutaneous Nephrolithotomy in Septuagenarians and Beyond

Background: Life expectancy has continuously risen worldwide. Because the elderly may tolerate complications poorly, the risks and benefits of percutaneous nephrolithotomy (PCNL) in those patients should be discussed thoroughly. Objective: To analyze utility and operative outcomes of PCNL with respect to age. Materials and Methods: A retrospective study of PCNL was performed at Ramathibodi Hospital between 2011 and 2020. The patients were divided into two age groups, 1) below 70 years old and 2) 70 years old and above. Comparison of demographics, operative data, and postoperative outcomes were analyzed. Results: Of the 253 patients, the overall stone-free rate (SFR) was 59.7%. The SFR in younger groups and older groups were 59.4% (126/212) and 61.0% (25/41), respectively, which was not significantly different (p=0.999). There was a similar in-stone burden between the two groups (p=0.573). Patients in the older group had worse renal function, higher American Society of Anesthesiologists score, and more comorbidities, including hypertension and ischemic heart disease. However, estimated blood loss, length of hospital stay, operative time, percent change in eGFR, and complications were comparable between the groups. Conclusion: PCNL is a safe and effective treatment of kidney calculi in septuagenarians and older patients, even with the risk of higher comorbidities and poorer renal function than in younger patients. Keywords: Percutaneous nephrolithotomy; Renal calculus; Stone-free status; Septuagenarians

XIST Inhibition Attenuates Calcium Oxalate Nephrocalcinosis-Induced Renal Inflammation and Oxidative Injury via the miR-223/NLRP3 Pathway

The roles of the lncRNA X inactive specific transcript (XIST) in many diseases, including cancers and inflammatory sickness, have been previously elucidated. However, renal calculus remained poorly understood. In this study, we revealed the potential effects of XIST on kidney stones that were exerted via inflammatory response and oxidative stress mechanisms. We established a glyoxylate-induced calcium oxalate (CaOx) stone mouse model and exposed HK-2 cells to calcium oxalate monohydrate (COM). The interactions among XIST, miR-223-3p, and NOD-like receptor protein 3 (NLRP3) and their respective effects were determined by RNAs and protein expression, luciferase activity, and immunohistochemistry (IHC) assays. Cell necrosis, reactive oxygen species (ROS) generation, and inflammatory responses were detected after silencing XIST, activating and inhibiting miR-223-3p, and both knocking down XIST and activating miR-223-3p in vitro and in vivo. The XIST, NLRP3, caspase-1, and IL-1β levels were notably increased in kidney samples from glyoxylate-induced CaOx stone model mice. XIST knockdown significantly suppressed the inflammatory damage and ROS production and further attenuated oxalate crystal deposition. miRNA-223-3p mimics also exerted the same effects. Moreover, we verified the interactions among XIST, miRNA-223-3p and NLRP3, and the subsequent effects. Our results suggest that the lncRNA XIST participates in the formation and progression of renal calculus by interacting with miR-223-3p and the NLRP3/Caspase-1/IL-1β pathway to mediate the inflammatory response and ROS production.

219 Have New National Guidelines Changed Practice in Referrals with Suspected Ureteric Colic?

Aim To assess how many patients had a non-contrast CT as first-line investigation for suspected renal colic, and how this was affected by the release of the 2019 NICE guidelines. A secondary aim was to assess the proportion of patients who had CT KUBs that demonstrated a ureteric calculus. Method CT KUB scans performed over two separate 3 month periods were identified. These reflected periods of time before and after the new NICE guidelines. Electronic records were used to assess if the patients had an ultrasound performed as the initial diagnostic investigation, instead of a CT scan. The results of the scans were reviewed to identify if a ureteric or renal calculus had been positively identified. Results In the period before the new guidelines, 61 patients were scanned. 4 had an ultrasound to assess for a stone prior to a CT. All of these patients were medical inpatients. None of the ultrasounds diagnosed a stone. 22/61 patients had CT-proven stones (36%) In the period after the new guidelines, 79 patients were scanned. 12 had an ultrasound to assess for a stone prior to a CT. 8 were medical patients, 3 were surgical and 1 was gynaecological. 1 ultrasound diagnosed a stone. 28/79 patients had CT-proven stones (35.4%) Conclusions The release of new guidelines did not improved compliance with suggested imaging pathways. This clearly demonstrates an area for improvement. It is also worth noting that only 1/3 of referrals with suspected renal colic did actually have a stone, which has implications for specialty referral pathways.

1242 A Surfacing Staghorn: Spontaneous Expulsion of a Large Renal Calculus from A Nephrocutaneous Fistula

An 83-year-old lady presented to the urology department with right flank pain in the context of a previously known right renal staghorn calculus. On examination, she was found to have a visible discharging sinus in her right flank, and the renal calculus had become visible at the skin surface. Non-contrast CT imaging confirmed that her staghorn calculus had eroded through the skin via a nephrocutaneous fistula. The stone was manually extracted percutaneously on the ward, and she was treated with intravenous antibiotics. She subsequently passed a further stone through the tract and made a good recovery. This is a highly unusual presentation of nephrolithiasis in a developed country in the 21st century. Review of the literature suggests that surgical management is almost always indicated in patients with staghorn calculi. However surgical management options are not without risk and conservative management of staghorn disease may be appropriate in select patient groups: those with multiple co-morbidities at high risk for GA, in cases of patient refusal of surgery, or in patients with aberrant anatomical factors Our case highlights a potential complication of conservatively managed staghorn stone disease. To our knowledge our case is the first of spontaneous expulsion of renal stone of this size to be reported in the developed world.

Effect of Alkalized Urine on Renal Calculi in Patients With Gout: a Protocol for a Randomized Controlled Trial

Background: The prevalence of renal calculi in patients with gout is high. Alkalized urine has been recommended by the 2020 European Association of Urology (EAU) guidelines to promote calculus dissolution. However, randomized controlled trials are lacking. Hence, it wasn't recommended by the 2020 American College of Rheumatology (ACR) guidelines. Objective: The present study aimed to determine the effect of sodium bicarbonate-alkalized urine on renal calculus in patients with gout. Methods: In this randomized, placebo-controlled, double-blinded trial, patients with gout combined with renal calculi are randomized (1:1) to the placebo and sodium bicarbonate groups. All patients were administered febuxostat (40 mg/day) and concomitant anti-inflammatory prophylaxis therapy. The 1–12-week group is double-blinded, and the 13–24-week group is open-labeled. The primary outcome is the rate of patients whose renal calculus volume is reduced after 12 weeks. The secondary outcomes included the volume changes of renal calculi, uric acid changes, the rate of patients with serum uric acid (sUA) levels < 360 μmol/L, the changes in estimated glomerular filtration rate (eGFR), the pH value of urine, and the adverse effects after 12 and 24 weeks.Discussion: This trial would evaluate the efficacy and safety of sodium bicarbonate-alkalized urine on renal calculi in patients with gout.Trial registration: ChiCTR, ChiCTR2100045183, Registered 7 April 2021http://www.chictr.org.cn/showproj.aspx?proj=124742

Surgical management of spontaneously ruptured kidney with peritonitis due to neglected renal and ureteric calculi

A 30-year-old woman presented with right-sided abdominal pain associated with fever. Her ultrasound showed right renal calculus with no hydronephrosis along with collection in peritoneal cavity and pouch of Douglas. CT showed ruptured right kidney with multiple renal and ureteric calculi as well as displaced renal calculi in perinephric space and pararenal space. Exploratory laparotomy and right nephroureterectomy were done. Nephrolithiasis with secondary infection makes the kidney fragile due to pathological changes, which may cause rupture of the renal calyces with trivial trauma or may be spontaneous. Distal obstruction by the stone and increased back pressure in the calyces may have added to the spontaneous rupture of the calyx and subsequently renal parenchyma. Management includes early exploration with nephrectomy and it is often life saving.