Removal Of Urinary Stones Research Articles

Ureteral stone volume and female gender predicts perioperative complications after complete ipsilateral upper urinary tract stone removal using flexible ureterorenoscopy.

To identify the risk factors for perioperative complications to prevent perioperative complications after complete ipsilateral upper urinary stone removal using flexible ureterorenoscopy. We retrospectively examined 111 patients who underwent flexible ureterorenoscopy for ipsilateral renal stones with a diameter ≥ 5mm at the same time as ureterorenoscopy for ureteric stones. The flexible ureterorenoscopy procedures were performed following the fragmentation technique. Patients who experienced (complication group) and did not experience (non-complication group) perioperative complications were compared. The complication group included 33 patients with Clavien-Dindo classification scores of I, II, III, or IV and/or those with a body temperature of > 37.5℃ during hospitalization. The overall stone volume, stone-free rate and procedure duration were 1.71mL, 96.4% and 77min, respectively. The rate of perioperative complications was 29.7% (grade 1, 2 and 3 was 23.4%, 5.4% and 0.9%, respectively). Severe complications (Clavien-Dindo grade 4) were not observed. Multivariable analysis revealed that ureteral stone volume and female patients were independent predictors of perioperative complications after flexible ureterorenoscopy (p = 0.015 and 0.017, respectively). This study showed that ureteral stone volume and female gender have the possibility to increase perioperative complications. These preliminary data help to select for patients who are at low risk of complications. Therefore, in these selected patients, complete ipsilateral upper urinary tract stone removal using flexible ureterorenoscopy may reduce the recurrence of urolithiasis without increasing perioperative complications.

Renal Function Recovery After Urinary Stone Removal Is Diverse for Patients with Urinary Stones in Different Locations

Renal Function Recovery After Urinary Stone Removal Is Diverse for Patients with Urinary Stones in Different Locations

Dynamics of inflammatory reaction markers in patients under endourological interventions

Introduction. Urolithiasis is one of the most widespread urological diseases and infectious complications remain one of the most common adverse events after surgical interventions for urolithiasis. Currently, in routine clinical practice in most clinics in the country, for the purpose of postoperative control and detection of infectious complications is used: a clinical blood test with assessment of the dynamics of the blood leukocyte count. Unfortunately, the current edition of the clinical guidelines does not contain recommendations on what indicators of postoperative follow-up examinations the clinician should focus on in order to identify infectious and inflammatory complications. For this reason, the study of the value of other markers of the inflammatory response appears to be an actual task.Objective. To assess the relationship between the dynamics of laboratory markers of infectious-inflammatory complications and the incidence of infectious-inflammatory response after endoscopic stone removal.Materials & methods. The prospective cohort study included 217 patients diagnosed with urolithiasis and underwent surgical removal of stones by endoscopic method. Of total patient numbers, 43 patients underwent ureteroscopy (URS) with lithotripsy, 152 patients underwent percutaneous nephrolithotripsy (PNL), and 22 patients underwent flexible ureterolithotripsy with lithotripsy. An analysis of demographics, clinical parameters and postoperative complications was performed as a descriptive analysis. Patients underwent a standard list of laboratory and instrumental examination methods. The mandatory control of body temperature was carried out t.i.d. daily. Before surgical treatment, indicators of WBC, LYMP, CRP, and ESR content were recorded on the first and second days after surgical treatment.Results. Postoperative fever was recorded in 40 (18.5%) patients. During the postoperative period, an increase in CRP and ESR was observed in both the fever and the normal temperature group, exceeding the reference values on the first day. At the same time, in the fever group (in 40 patients — 18.5%), a significantly higher increase in CRP and ESR was observed (685% vs 323%) for CRP and (146% vs 80%) for ESR. According to the results obtained in our study, CRP and ESR indicators demonstrate the most clinically significant dynamics in patients with postoperative fever, increasing by more than 500% and 100%, respectively.Conclusions. Endoscopic removal of urinary stones is a safe treatment option in patients with sterile urine cultures. After endoscopic stone removal, all patients experience such reactive changes in peripheral blood parameters as: an increase in the level of leukocytes, lymphopenia, an increase in ESR and CRP levels. Indicators of CRP and ESR demonstrate the most clinically indicative dynamics.

In Vivo Prediction of Kidney Stone Fragility Using Radiomics-Based Regression Models.

Introduction: The surgical technique for urinary stone removal is partly influenced by its fragility, as prognosticated by the clinician. This feasibility study aims to develop a linear regression model from CT-based radiomic markers to predict kidney stone comminution time in vivo with two ultrasonic lithotrites. Materials and Methods: Patients identified by urologists at our institution as eligible candidates for percutaneous nephrolithotomy were prospectively enrolled. The active engagement time of the lithotrite in breaking the stone during surgery denoted the comminution time of each stone. The comminution rate was computed as the stone volume disintegrated per minute. Stones were grouped into three fragility classes (fragile, moderate, hard), based on inverse of the comminution rates with respect to the mean. Multivariable linear regression models were trained with radiomic features extracted from clinical CT images to predict comminution times in vivo. The model with the least root mean squared error (RMSE) on comminution times and the fewest misclassification of fragility was finally selected. Results: Twenty-eight patients with 31 stones in total were included in this study. Stones in the cohort averaged 1557 (±2472) mm3 in volume and 5.3 (±7.4) minutes in comminution time. Ten stones had nonmoderate fragility. Linear regression of stone volume alone predicted comminution time with an RMSE of 6.8 minutes and missed all 10 stones with nonmoderate fragility. A fragility model that included stone volume, internal morphology, shape-based radiomics, and device type improved RMSE to below 3.3 minutes and correctly classified 20/21 moderate and 6/10 nonmoderate stones. Conclusions: CT metrics-based fragility models may provide information to surgeons regarding kidney stone fragility and facilitate the selection of stone removal procedures.

Outcomes for Geriatric Urolithiasis Patients aged ≥80 Years Compared to Patients in Their Seventies

BackgroundDemographic changes are leading to an increase in geriatric urolithiasis patients aged ≥70 yr. Published data regarding their management remain sparse. In particular, for the subgroup of patients aged ≥80 yr there is a lack of evidence supporting the hypothesis that stone-removing treatment is effective, safe, and beneficial. ObjectiveTo examine the efficiency and safety of stone-removing treatment in geriatric urolithiasis patients aged ≥80 yr compared to their younger geriatric counterparts aged 70–79 yr against the background of their respective life expectancy. Design, setting, and participantsData for the study cohort were extracted from an institutional review board–approved retrospective database with 325 patients aged ≥70 yr (70–79 yr: n = 241; ≥80 yr: n = 84) consecutively admitted to hospital because of symptomatic urolithiasis from 2013 to 2018. Outcome measurements and statistical analysisBaseline characteristics, outcome and follow-up data, and survival were compared using Wilcoxon-Mann-Whitney U tests, χ2 tests, Kaplan-Meier estimation, log-rank tests, and Cox regression. Results and limitationsAt baseline, the incidence of infected hydronephrosis was greater among patients aged ≥80 yr (p < 0.05), whereas the median stone burden and Charlson comorbidity index did not differ between the groups. Outcome analysis revealed no significant differences in terms of complication, stone-free, and 6-mo readmission rates (p > 0.05). Survival analysis for the two groups demonstrated a 2-yr overall survival (OS) rate of 0.91 (95% confidence interval [CI] 0.75–1) for patients aged ≥80 yr and 0.97 (95% CI 0.88–1), for those aged 70–79 yr (p < 0.01). Multivariable Cox analysis revealed age ≥80 yr (hazard ratio [HR] 3.3, 95% CI 1.3–8.5) and infected hydronephrosis (HR 2.8, 95% CI 1.0–7.8) as predictors of all-cause mortality (p < 0.05). The study is limited by its retrospective design. ConclusionsStone-removing treatment for patients aged ≥80 yr proved to be as effective and safe as for patients in their seventies. Although characterized by shorter remaining life expectancy, excellent 2-yr OS for patients aged ≥80 yr supports the hypothesis of equal benefit from stone-removing treatment when compared to septuagenarians. Patient summaryThere is a lack of evidence supporting the benefit of urinary stone-removing treatment for patients older than 80 yr. Our study included geriatric patients older than 70 yr with symptomatic urinary stone disease for which urinary drainage or stone removal is indicated. We compared treatment outcomes and survival between two age groups: patients aged 70–79 yr and those aged 80 yr or older. We found equivalent outcomes for the two groups and excellent 2-yr overall survival of 91% for those older than 80 yr. The study strengthens the evidence that active stone-removing therapy is safe and beneficial for these patients.

Design and construction of holmium:yttrium aluminum garnet laser for lithotripsy applications

A holmium:yttrium aluminum garnet (Ho:YAG) laser is mainly used in medical surgeries such as tissue ablation and removal of urinary stones. In the present study, a 20 W solid-state 2.08 μm Ho:YAG laser was designed and implemented for lithotripsy applications. Effects of the temporal profile beam of the Ho:YAG laser on stone fragmentation were demonstrated. Moreover, the power supply driver of the xenon flashlamp was implemented with a distinctive trigger circuit at the start of the laser operation. The home-built power driver was customized to deliver a 0.2–3 ms rectangular pulse duration between 1 and 20 Hz frequencies. Laser pulse energies at 5 Hz in response to pumping energy were measured with 3.55% slope efficiency. Similarly, laser pulse energies at 10 Hz were recorded with a slope efficiency of 2.96%. Overall, 1.7% wall-plug (electrical to optical) efficiency was obtained at 5 and 10 Hz laser operations.

Diagnostics and correction of metabolic disorders in patients with recurrent urolithiasis after endoscopic removal of stones

The article is devoted to the problem of kidney stones. The authors provide the results of a study of 107 men aged 48 to 76 years, were divided into three groups – primary and two control groups. The main and the first control group consisted of 40 patients with recurrent urolithiasis without urinary tract obstruction after endoscopic stone removal and partial androgen deficiency. The second control group consisted of 27 healthy men aged 48 to 70 years. Patients for one year he was promoted endoscopic removal of urinary stones: transurethral nephrolithotripsy – 55 patients, and percutaneous nephrolithotripsy – 25. After discharge from hospital all patients had a diagnosis and correction of metabolic disorders using physical-chemical and biochemical indicators of urine and blood. To study the mineral composition and structural-textural features of urinary stones and their fragments after surgical interventions were performed: x-ray diffraction, infrared spectroscopy, polarization and electron microscopy. Was carried out following the relapse of urolithiasis: patients of the main group received pathogenetic androgen therapy as monotherapy, and patients in the control group conventional treatment (antibiotics, spasmolytic, herbal remedies). The results of therapy and follow-up care for 6 years showed a low recurrence of stone formation in patients of the main group and highest in the control. Age-related decline in androgen levels in men may be an additional factor in stone formation. Pathogenic androgen replacement therapy leads to normalization of the content of lithogenic substances in the blood and urine, as well as physico-chemical properties of urine, thereby reducing the process of stone formation.

Long-term prescription of α-blockers decrease the risk of recurrent urolithiasis needed for surgical intervention-a nationwide population-based study

PURPOSE α1 receptors and subtypes have been confirmed to distribute in human pelvis and calyces recently. As used in ureteral stones, α-blocker treatment may facilitate kidney stone passage and long-term prescription of α-blocker may decrease the risk of recurrent urolithiasis. The aim of this study is to determine if use of α-blockers 180 days or more can decrease the risk of recurrent urolithiasis needed for surgical intervention. MATERIALS AND METHODS A representative database of 1,000,000 patients from Taiwan's National Health Insurance was analyzed. Eligible patients were those who had received the first-time procedure for upper urinary stone removal, including extracorporeal shock-wave lithotripsy, ureterorenoscopic lithotripsy, or both, between 2000 and 2010. After completing a 180-day treatment for first event, patients were prospectively followed-up until a second set of stone procedures was performed (proxy of stone recurrence), loss to follow-up, or end of study. The effect of percentage of total number of days of α-blocker use on need for second set of stone procedures within a post treatment 180-day follow-up period was analyzed by quartile. A nested case-control study was also performed. RESULTS 1,259 patients were eligible for final analyses. During 3,980 person-years follow-up, 167 patients had recurrent urolithiasis needed for surgical intervention. From first to fourth quartile of drug exposure, recurrence rates were 45.64, 47.19, 43.11, and 18.52 per 1,000 person-years. The adjusted hazard ratio was 0.46 (95% CI = 0.24 to 0.89) for the fourth quartile (vs. quartile 1). In the nested case-control study, adjusted ORs was 0.23 (95% CI = 0.10 to 0.53) in the fourth quartile (vs. quartile 1). The results remained similar even in patients categorized by cumulative defined daily dose (cDDD) quartiles and average cDDD per day quartiles. CONCLUSION Use of α-blockers for 180 days or more decrease the risk of recurrent urolithiasis needed for surgical intervention. In patients at higher risk of recurrent urolithiasis, long term prescription of α-blockers might help them prevent further surgical intervention.

Long-Term Prescription of α-Blockers Decrease the Risk of Recurrent Urolithiasis Needed for Surgical Intervention-A Nationwide Population-Based Study

Purposeα1 receptors and subtypes have been confirmed to distribute in human pelvis and calyces recently. As used in ureteral stones, α-blocker treatment may facilitate kidney stone passage and long-term prescription of α-blocker may decrease the risk of recurrent urolithiasis. The aim of this study is to determine if use of α-blockers 180 days or more can decrease the risk of recurrent urolithiasis needed for surgical intervention.Materials and MethodsA representative database of 1,000,000 patients from Taiwan’s National Health Insurance was analyzed. Eligible patients were those who had received the first-time procedure for upper urinary stone removal, including extracorporeal shock-wave lithotripsy, ureterorenoscopic lithotripsy, or both, between 2000 and 2010. After completing a 180-day treatment for first event, patients were prospectively followed-up until a second set of stone procedures was performed (proxy of stone recurrence), loss to follow-up, or end of study. The effect of percentage of total number of days of α-blocker use on need for second set of stone procedures within a post treatment 180-day follow-up period was analyzed by quartile. A nested case-control study was also performed.Results1,259 patients were eligible for final analyses. During 3,980 person-years follow-up, 167 patients had recurrent urolithiasis needed for surgical intervention. From first to fourth quartile of drug exposure, recurrence rates were 45.64, 47.19, 43.11, and 18.52 per 1,000 person-years. The adjusted hazard ratio was 0.46 (95% CI = 0.24 to 0.89) for the fourth quartile (vs. quartile 1). In the nested case-control study, adjusted ORs was 0.23 (95% CI = 0.10 to 0.53) in the fourth quartile (vs. quartile 1). The results remained similar even in patients categorized by cumulative defined daily dose (cDDD) quartiles and average cDDD per day quartiles.ConclusionUse of α-blockers for 180 days or more decrease the risk of recurrent urolithiasis needed for surgical intervention. In patients at higher risk of recurrent urolithiasis, long term prescription of α-blockers might help them prevent further surgical intervention.

Can a dual-energy computed tomography predict unsuitable stone components for extracorporeal shock wave lithotripsy?

PurposeTo assess the potential of dual-energy computed tomography (DECT) to identify urinary stone components, particularly uric acid and calcium oxalate monohydrate, which are unsuitable for extracorporeal shock wave lithotripsy (ESWL).Materials and MethodsThis clinical study included 246 patients who underwent removal of urinary stones and an analysis of stone components between November 2009 and August 2013. All patients received preoperative DECT using two energy values (80 kVp and 140 kVp). Hounsfield units (HU) were measured and matched to the stone component.ResultsSignificant differences in HU values were observed between uric acid and nonuric acid stones at the 80 and 140 kVp energy values (p<0.001). All uric acid stones were red on color-coded DECT images, whereas 96.3% of the nonuric acid stones were blue. Patients with calcium oxalate stones were divided into two groups according to the amount of monohydrate (calcium oxalate monohydrate group: monohydrate≥90%, calcium oxalate dihydrate group: monohydrate<90%). Significant differences in HU values were detected between the two groups at both energy values (p<0.001).ConclusionsDECT improved the characterization of urinary stone components and was a useful method for identifying uric acid and calcium oxalate monohydrate stones, which are unsuitable for ESWL.

A brief history of recognition on urolithiasis before medieval period

Urinary stone was first found by human as early as 4900 BC when the Egyptian monks applied emesis, catharsis, diuresis, and diaphoresis for its treatment which, as they claimed, can expel the stones out of the body occasionally. In 2700 BC, definite records on urinary stone were seen in Egytian papyrus which attempted to cure this disorder by sucking method. In the 4(th) century BC, the Greek physician Alexandria mentioned that such stones can be expelled after being smashed. By then, the Greeks recognized the existence of renal stone by describing its manifestations. Sushruta, an ancient Indian royal physician mentioned in 6(th) century BC, the picking up of stones by splints through the urethra and the complications of such disorder in his Sushrutasamhita. He also recommended the removal of stones through the perineal part. Unfortunately, many patients died of such operation. Ancient Roman physicians described such operation circumstantially and the herbs for its treatment in the 1(st) century BC. During the 10(th) century, the Arabian physician Abukasis was the first to advocate the method of smashing stones in the urethra with an instrument he devised. In the period before medieval age, the removal of urinary stones through the perineal incision had been the main method which was so limited an approach due to the lack of anatomical knowledge and antiseptic conception.

Nephrocalcinosis: re-defined in the era of endourology

Nephrocalcinosis generally refers to the presence of calcium salts within renal tissue, but this term is also used radiologically in diagnostic imaging in disease states that also produce renal stones, so that it is not always clear whether it is tissue calcifications or urinary calculi that give rise to the characteristic appearance of the kidney on x-ray or computed tomography (CT). Recent advances in endoscopic imaging now allow the visual distinction between stones and papillary nephrocalcinosis, and intrarenal endoscopy can also verify the complete removal of urinary stones, so that subsequent radiographic appearance can be confidently attributed to nephrocalcinosis. This report shows exemplary cases of primary hyperparathyroidism, type I distal renal tubular acidosis, medullary sponge kidney, and common calcium oxalate stone formation. In the first three cases--all being conditions commonly associated with nephrocalcinosis--it is shown that the majority of calcifications seen by radiograph may actually be stones. In common calcium oxalate stones formers, it is shown that Randall's plaque can appear as a small calculus on CT scan, even when calyces are known to be completely clear of stones. In the current era with the use of non-contrast CT for the diagnosis of nephrolithiasis, the finding of calcifications in close association with the renal papillae is common. Distinguishing nephrolithiasis from nephrocalcinosis requires direct visual inspection of the papillae and so the diagnosis of nephrocalcinosis is essentially an endoscopic, not radiologic, diagnosis.

Infection-induced urinary stones

Infection stones make up approximately 15% of urinary stone diseases and are thus an important group. These stones are composed of struvite and/or carbonate apatite. The basic precondition for the formation of infection stones is a urease-positive urinary tract infection. Urease is necessary to split urea into ammonia and CO(2). As a result, ammonia ions can form and at the same time alkaline urine develops, both being preconditions for the formation of struvite and carbonate apatite crystals. When these crystals are deposited infection stones form. Pathogenetically, various risk factors play a role: urinary obstruction, neurogenic bladder, dRTA, and MSK. If these infections are not treated and the stones are not removed, the kidney will be damaged. Modern methods are available for stone removal, e.g., ESWL and/or instrumental urinary stone removal. Here, especially less invasive methods are preferable. Any treatment must be adjusted to the patient individually. Patients should be examined frequently for recurrent urinary tract infections and stone recurrences, and new infections must be resolutely treated. Good therapy and prophylaxis are possible with present-day treatment modalities.

Urinary infection stones

Infection stones make up approximately 15% of urinary stone diseases and are thus an important group. These stones are composed of struvite and/or carbonate apatite. The basic precondition for the formation of infection stones is a urease positive urinary tract infection. Urease is necessary to split urea to ammonia and CO 2. As a result, ammonia ions can form and at the same time alkaline urine develops, both being preconditions for the formation of struvite and carbonate apatite crystals. When these crystals deposit themselves infection stones form. If these infections are not treated and the stones are not removed, the kidney will be damaged. For stone removal modern methods are available, e.g. ESWL and/or instrumental urinary stone removal. Here especially less invasive methods are preferable. Any treatment must be adjusted to the patient individually. Patients should be examined frequently for recurrent urinary tract infections and stone recurrences and, newly arising infections must be resolutely treated. Good therapy and prophylaxis are possible with present-day treatment modalities.

ENDOSCOPIC MAPPING OF RENAL PAPILLAE FOR RANDALL'S PLAQUES IN PATIENTS WITH URINARY STONE DISEASE

Purpose Papillary "Randall's plaques" are theorized to act as nidi for urinary stone formation. The aim of this study was to document the presence, pattern and distribution of Randall's plaques in patients undergoing endoscopic procedures for urinary stone disease. Materials and Methods Patients undergoing either ureteroscopy or percutaneous nephroscopy for removal of urinary stones underwent endoscopic mapping of accessible calices. These patients were compared to a smaller group of patients undergoing endoscopic procedures for conditions unrelated to urinary stone disease. In patients found to have papillary plaques the presence, location and pattern of plaques were recorded. Plaque formation was correlated with patient age and sex, and primary composition of extricated stone. Results Endoscopic evidence of papillary Randall's plaques was found in 74% of 57 patients having ureteroscopic (21) or percutaneous (36) stone removal. Of 7 patients having endoscopic procedures for conditions unrelated to urinary stone disease 3 (43%) had evidence of papillary plaques. Plaques were found uniformly throughout all calices and most commonly diffusely scattered over the papillary surface. There was no correlation between patient age or sex and the presence of plaques. The incidence of plaques varied with the primary composition of extracted stones, and was 100% for calcium phosphate and uric acid, 88% for calcium oxalate, 33% for cystine and 20% for struvite. The incidence of papillary plaques was significantly more common in patients with calcium oxalate (88 versus 43%, p = 0.023) and calcium phosphate stones (100 versus 43%, p = 0.009) than patients without a history of urinary stone disease. Conclusions The endoscopic incidence of papillary Randall's plaques in patients with urolithiasis varies with the primary composition of formed urinary stones. Randall's plaques are found in the majority of patients with calcium urinary stone disease. Our findings suggest that the presence of papillary plaques is associated with calcium nephrolithiasis and may contribute to the pathogenesis of calcium urinary stones.

Urinary sodium to potassium ratio and urinary stone disease

The relation was investigated of urinary sodium to potassium ratio in first morning voided urine (spot urine) to urinary stone disease in 3,625 men and women aged 25 to 74 years participating in the baseline examination of the Gubbio Population Study. History of urinary stone disease (excretion of stone, and/or radiographic or ultrasonic evidence of urinary stone, and/or operation for urinary stone removal) was reported by 127 individuals (3.50%). Prevalence of urinary stone disease was lower in women than in men (2.59 and 4.58%, P < 0.001) and positively related to age (P < 0.001). Compared to nonstone formers, stone formers (N = 127) had higher urinary sodium to potassium ratio (P < 0.01), with similar plasma potassium and sodium concentration. In both sexes, urinary stone disease was positively related (P < 0.001) to sodium to potassium ratio: quartile analysis of this ratio showed that prevalence of stone formers in quartile 4 compared to quartile 1 was 3.33 times higher in women (P < 0.005, 95% confidence interval 1.36/8.60) and 2.71 times higher in men (P < 0.004, 95% confidence interval 1.35/5.93). In multiple logistic regression, urinary stone disease was significantly related to age, sex, and urinary sodium to potassium ratio (P < 0.01), controlled for other possible confounders, with or without exclusion of stone formers with plasma creatinine > 1.20 mg/dl. In an alternative model, with urinary sodium to potassium ratio not included, urinary stone disease was positively related to urinary sodium to creatinine ratio (P < 0.001) and weakly (P = 0.079) related inversely to urinary potassium to creatinine ratio.(ABSTRACT TRUNCATED AT 250 WORDS)