Relationship Between Spontaneous Passage Rates of Ureteral Stones Less Than 8 mm and Serum C-Reactive Protein Levels and Neutrophil Percentages

Neutrophil to lymphocyte ratio and serum procalcitonin level as a predictor of spontaneous ureteral stone passage: A prospective study

BACKGROUND

Ureteric stone is responsible for around 20% of urinary tract stones and among them 70% of these are located in distal portion of the ureter. Stone causing ureter obstruction produce inflammatory changes in ureteric wall and prevent spontaneous passage of stone. The objective of the study is to compare the predictive role of procalcitonin and Neutrophil-to-lymphocyte ratio (NLR) for spontaneous passage of stone.

MATERIALS AND METHODOLOGY

Total 150 participants having ureteric stone of 4-8 mm, were included in prospective observational study. The patients were followed up for 4 weeks. Spontaneous Stone Passage (SSP) was confirmed with either the patient collecting the stone during urination or by Non-Contrast CT performed at 4 weeks. Blood samples of the patients were analysed and White blood cells, sedimentation, Neutrophile to Lymphocyte (NLR), procalcitonin level compared to analyse predictors of future SSP.

RESULT

The procalcitonin levels of the Spontaneous stone passing SSP (-ve) group (209.05 ± 78.45 pg/ml) were significantly higher than the not passing the SSP (+ve) group (130.76 ± 24.18) (p < 0.001). NLR is significantly higher in the SSP -ve (3.84 ± 0.41) than the SSP +ve (2.18 ± 0.38) group (p < 0.001). In single and multivariate analysis, significant activity was found for procalcitonin in SP +ve group.

CONCLUSION

The findings of the study suggests that high level of procalcitonin, and high NLR have a negative effect on passage of stone. So early intervention can be planned to these patients to prevent complications.

Predictive value of inflammatory markers for the spontaneous passage of Ureteral stones: a comprehensive systematic review with meta analysis

Urolithiasis is a common disease that affects approximately one-fifth of the global population. This systematic review explores the predictive role of inflammatory markers for the spontaneous passage of ureteral stones. The literature was systematically searched via Google Scholar, PubMed/MEDLINE, the Cochrane Library, Science Direct, CINAHL, Web of Science, and EMBASE databases to identify papers published until 2023. Overall, 26 articles were identified, of which 10 were excluded. The remaining 16 papers reported 2,695 patients (1,723 males and 972 females), with 1,654 (61.37%) experiencing spontaneous stone passage (SSP) and 1,041 (38.63%) not experiencing it (non-SSP). Stones located in the upper part of the ureter were less likely to pass spontaneously (152/959, 15.94% in the SSP group vs. 180/546, 32.48% in the non-SSP group; p < 0.001). Mid-ureteral stones were present in 180/959 (18.75%) of the SSP group compared to 84/546 (14.52%) of the non-SSP group (p = 0.0974). Lower ureteral stones were more likely to pass spontaneously, with 627/959 (63.31%) in the SSP group compared to 282/546 (49.36%) in the non-SSP group (p < 0.001). No significant correlation was found between most inflammatory markers and SSP (p > 0.05). However, procalcitonin levels were lower in the SSP group compared to the non-SSP group (132.7 ± 28.1 vs. 207 ± 145.1, respectively) (p < 0.001). This systematic review has revealed that except procalcitonin, most inflammatory markers do not offer significant predictive capability for ureteral SSP.

Predictive Value of C-reactive Protein in the Spontaneous Passage of Lower Ureteric Stones: A Prospective Single-Centre Study

INTRODUCTION

Ureteric stones, characterised by their presence in the ureter, present a common yet often painful urological condition requiring timely intervention. As C-reactive protein (CRP) emerges as a potential biomarker, its correlation with the spontaneous stone passage (SSP) offers valuable insights into patient management and treatment strategies. The present study aimed to assess if CRP levels can predict SSP in symptomatic lower ureteric calculi of size 5 mm-10 mm.

MATERIALS AND METHODS

This prospective observational study, conducted at the Indira Gandhi Institute of Medical Sciences in Patna, India, from July 2022 to June 2023, focused on individuals aged 13 to 60 years presenting with ureteric colic and single distal ureteral stones (5 mm-10 mm). Patients underwent comprehensive initial assessment and monitoring, including diagnostic procedures such as a complete blood count, urinalysis, CRP levels, and renal function evaluations. Treatment consisted of hydration encouragement, tamsulosin (0.4 mg) daily administration, and diclofenac (50 mg) as needed. Follow-up assessments at one-month post-treatment involved clinical examination and imaging studies to evaluate treatment efficacy.

RESULTS

This study analysed 157 patients with ureteric stones, finding that 76% experienced SSP. Lower CRP levels (≤6 mg/L), along with other laboratory parameters like low white blood cell counts, low neutrophil levels, absence of leukocyturia, absence of hematuria, and lower urine specific gravity, were associated with higher SSP rates. C-reactive protein levels ≤6 mg/L emerged as a strong predictor of SSP in multiple regression analysis.

CONCLUSION

The findings underscore the potential utility of CRP as a predictive biomarker in guiding the management and treatment strategies for ureteric stones.

Role of the systemic immune-inflammation index in predicting spontaneous stone passage in patients with renal colic

OBJECTIVES

Renal colic (RC) is one of the most frequent reasons for presentation to the emergency department (ED) and creates a high economic and medical burden. Management strategies for RC range from waiting for spontaneous passage to surgical intervention. However, factors determining spontaneous stone passage (SSP) are still poorly understood. Therefore, in this study, we aimed to investigate the role of the systemic immune-inflammatory index (SII) in predicting SSP.

METHODS

We retrospectively analyzed the data of 924 patients aged over 18 years, who were diagnosed with RC in our clinic between 1 January 2019, and 30 May 2022, and had ureteral stones of ≤ 10 mm. The patients were divided into two groups according to whether they had SSP. The clinical and laboratory characteristics of the patients in the ED were evaluated. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and SII (neutrophil count x platelet count/lymphocyte count) values of the patients were calculated. Stone size and location were also recorded.

RESULTS

In the univariate analysis of SSP, a ureteral stone size of ≤ 5 mm (p < 0.001), distal ureteral location (p < 0.001), SII (p < 0.001), NLR (p < 0.001), and PLR (p = 0.036) were significantly correlated with SSP. ROC analysis showed that an SII level < 721.8 (Sensitivity %82.6, Specificity %74.7, p < 0.001) was an independent predictor of SSP.

CONCLUSION

Our findings showed that a low SII level was associated with SSP and could be used as a predictive marker of SSP as a more valuable parameter than NLR. SII and NLR, together with other indicators, are inflammatory markers that can be used in the clinical decision-making process for ureteral stone treatment.

Inflammation and kidney stones: cause and effect?

PURPOSE OF REVIEW

This short review is intended to highlight the potential role of inflammation as a key pathological driver, rather than a mere consequence, of nephrolithiasis. Although there is clearly a strong likelihood that the relationship is bidirectional, and that kidney stone-triggered inflammation can establish a vicious cycle of tissue injury and stone formation.

RECENT FINDINGS

These consist of data from both recent preclinical and clinical studies demonstrating the importance of inflammation in models of stone disease and in kidney tissue from patients with nephrolithiasis, and as a potential driver of disease recurrence and a suitable treatment target. In particular, the role of immune cells and their relationship to the NLRP3 inflammasome is becoming clearer, as well as the potential contribution to tissue injury and stone formation of the pro-inflammatory cytokines interleukin-1β and interleukin-18.

SUMMARY

This concept is not new and raises the possibility that targeting inflammation directly may prove to be a novel and suitable means of treatment for at least some types of kidney stone, and in certain clinical settings, both acutely and as prevention, especially in those patients experiencing recurrent stone episodes and/or who have a well defined metabolic cause such as uric acid or calcium oxalate stones.

Spontaneous stone expulsion in patients with history of urolithiasis

Objectives:

To examine differences in the presentation, management, and outcomes of patients admitted to the emergency department (ED) with ureteral stones, with prior history of urolithiasis compared to patients with a first stone event.

Patients and Methods:

Retrospective analysis of patients who visited the ED that were found to have a ureteral stone on CT. Patients were stratified into two groups: without history of urolithiasis (Group 1) and with history of urolithiasis (Group 2).

Results:

Between 2018 and 2020, 778 patients were admitted with ureteral stones. Patients in group 1 presented with a higher mean serum creatinine ( p = 0.02), larger mean stone size ( p < 0.0001), and a higher proportion of proximal ureteral stones ( p < 0.0001) than patients in group 2. The 30 day readmission rate was significantly higher in group 1 ( p = 0.02). Spontaneous stone expulsion was higher in group 2 ( p < 0.0001), whereas the need for endourological procedures was higher in group 1 ( p < 0.0001). On multivariable analysis serum creatinine (OR 0.264, 95% CI 0.091–0.769, p = 0.01) and stone size (OR 0.623, 95% CI 0.503–0.771, p < 0.0001) were associated with a lower spontaneous stone expulsion rate. History of prior endourological procedures (OR 0.225, OR 0.066–0.765, p = 0.01) was associated with a higher spontaneous stone expulsion rate.

Conclusions:

Our data suggests that patients who are first time stone formers present with larger and more proximal ureteral stones, with a lower likelihood of spontaneous stone expulsion and a subsequent need for surgical intervention. Previous stone surgery and not previous stone expulsion was found to be a predictor for spontaneous stone passage.

The role of inflammatory serum markers and ureteral wall thickness on spontaneous passage of ureteral stone < 10 mm: A prospective cohort study

Introduction

Ureteral stone is a worldwide disease and accounts for 20% of all urolithiasis. There is a widespread discussion on the preferred initial treatment method, whether medical or surgical, and each has its pros and cons. In this study, we aimed to assess the role of both ureteral wall thickness around the stone and inflammatory markers in guiding the decision-making process.

Methods

In this prospective study, 161 patients who presented with ureteric colic and were diagnosed with ureteral stone with NCCT were included. UWT around the stone was measured, and the NLR and PLR were calculated. The patients were given a single daily dose of tamsulosin 0.4 mg for 4 weeks with weekly follow-up to determine SSP or failure.

Results

Of the 161 patients with a mean age 40.12 ± 12.36 SD, 55.9% had a spontaneous stone passage. Receiver operating characteristics showed a cut off value of 2.45 mm UWT of non SSP patients with an 83% sensitivity and 86% specificity. Moreover, there was a significant correlation between higher NLR, PLR and increased UWT (Pearson correlation of 0.314 and 0.426 respectively). The combined higher NLR, PLR and increased UWT were associated with failure of SSP (p-value <0.001).

Conclusion

Many factors play a role in decision making for management of ureteral stones. Our study concludes that patients with high NLR, PLR, and UWT around the stone have lesser chance of SSP using MET. Their rise can be used as predictors to decide early intervention.

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Ureteral stone is a worldwide disease and accounts for 20% of all urolithiasis.

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Impacted ureteral stones occupy the majority of emergency department visits due to urolithiasis.

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The role of inflammatory serum markers and UWT around the stone on spontaneous passage are controversial.

A machine learning model for predicting surgical intervention in renal colic due to ureteral stone(s) < 5 mm

A 75-89% expulsion rate is reported for ureteric stones ≤ 5 mm. We explored which parameters predict justified surgical intervention in cases of pain caused by < 5 mm ureteral stones. We retrospectively reviewed all patients with renal colic caused by ureteral stone < 5 mm admitted to our urology department between 2016 and 2021. Data on age, sex, body mass index, the presence of associated hydronephrosis/stranding on images, ureteral side, stone location, medical history, serum blood count, creatinine, C-reactive protein, and vital signs were obtained upon admission. XGboost (XG), a machine learning model has been implemented to predict the need for intervention. A total of 471 patients (median age 49, 83% males) were reviewed. 74% of the stones were located in the distal ureter. 160 (34%) patients who sustained persistent pain underwent surgical intervention. The operated patients had proximal stone location (56% vs. 10%, p < 0.001) larger stones (4 mm vs. 3 mm, p < 0.001), longer length of stay (3.5 vs. 3 days, p < 0.001) and more emergency-room (ER) visits prior to index admission (2 vs. 1, p = 0.007) compared to those who had no surgical intervention. The model accuracy was 0.8. Larger stone size and proximal location were the most important features in predicting the need for intervention. Altogether with pulse and ER visits, they contributed 73% of the final prediction for each patient. Although a high expulsion rate is expected for ureteral stones < 5 mm, some may be painful and drawn out in spontaneous passage. Decision-making for surgical intervention can be facilitated by the use of the present prediction model.

What is the role of inflammatory markers in predicting spontaneous ureteral stone passage?

PURPOSE

To investigate the role of inflammatory markers in predicting the spontaneous passage of ureteral stones.

METHODS

We retrospectively reviewed 279 patients with ureteral stones sized 4-10 mm that were managed conservatively. The patients were divided into two groups: Group 1 consisted of 137 patients who passed the stone spontaneously; Group 2 comprised 142 patients without spontaneous stone passage. The groups were compared using the Mann-Whitney U and chi-square tests. In addition, univariate and multivariate analyses were performed to identify the significance of the parameters.

RESULTS

The mean age of the patients was 41.2 years. The patients in Group 1 had a significantly lower mean stone size, white blood cell count and neutrophil count. In addition, stone location, presence of hydronephrosis and history of urolithiasis were significantly different between the groups. Neutrophil percentage, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio were insignificantly lower in Group 1. In a multivariate analysis, stone size, distal location and hydronephrosis status significantly predicted the spontaneous stone passage. However, inflammatory markers including white blood cell count, neutrophil count and neutrophil-to-lymphocyte ratio could not determine the likelihood of spontaneous stone passage.

CONCLUSION

Our results suggest that inflammatory markers are no meaningful parameters for the prediction of spontaneous stone passage.

Role of inflammatory markers and their trends in predicting the outcome of medical expulsive therapy for distal ureteric calculus

Objective:

Symptomatic ureteric stones cause surrounding inflammation-promoting obstruction. C-reactive protein (CRP), white blood cell count (WC), and neutrophil percentage (NP) tend to rise after inflammatory response. Monitoring response during the course of medical expulsive therapy (MET) may help in deciding early intervention, thereby decreasing morbidity. We assessed the role and trends of these markers in predicting the outcome of MET.

Materials and Methods:

One hundred and ninety-two patients with distal ureteric calculus of size >5 mm were included in this prospective study from April 2017 to March 2018 after ethical committee approval. CRP, NP, and WC were measured on day 1, 7, and 14 of MET, and analysis was done.

Results:

On univariate analysis, stone size and mean values of CRP, WC, and NP on day 1, 7 and 14 in stone nonpassers were significantly higher compared to stone passers (P < 0.05). Receiver operator curve analysis showed area under the curve value of 0.798 (P = 0.001) for CRP and cut off value determined was 1.35 mg/dL. Multivariate analysis of different variables showed significant association of higher CRP (>1.35 mg/dL) and larger stone size (>7 mm) with MET failure. Decreasing trend of CRP was seen in both groups, but values were higher in stone nonpassers. WC and NP showed decreasing trend in stone passers but persistently high in stone nonpassers.

Conclusions:

Higher CRP and larger stone size were associated with failure of MET. WC and NP showed decreasing trend in stone passers and persistently higher in nonpassers, which may potentially predict failure of MET, however, their role need to be further studied.

Development of prediction models of spontaneous ureteral stone passage through machine learning: Comparison with conventional statistical analysis

Objectives

To develop a prediction model of spontaneous ureteral stone passage (SSP) using machine learning and logistic regression and compare the performance of the two models. Indications for management of ureteral stones are unclear, and the clinician determines whether to wait for SSP or perform active treatment, especially in well-controlled patients, to avoid unwanted complications. Therefore, suggesting the possibility of SSP would help make a clinical decision regarding ureteral stones.

Methods

Patients diagnosed with unilateral ureteral stones at our emergency department between August 2014 and September 2018 were included and underwent non-contrast-enhanced computed tomography 4 weeks from the first stone episode. Predictors of SSP were applied to build and validate the prediction model using multilayer perceptron (MLP) with the Keras framework.

Results

Of 833 patients, SSP was observed in 606 (72.7%). SSP rates were 68.2% and 75.6% for stone sizes 5–10 mm and <5 mm, respectively. Stone opacity, location, and whether it was the first ureteral stone episode were significant predictors of SSP. Areas under the curve (AUCs) for receiver operating characteristic (ROC) curves for MLP, and logistic regression were 0.859 and 0.847, respectively, for stones <5 mm, and 0.881 and 0.817, respectively, for 5–10 mm stones.

Conclusion

SSP prediction models were developed in patients with well-controlled unilateral ureteral stones; the performance of the models was good, especially in identifying SSP for 5–10-mm ureteral stones without definite treatment guidelines. To further improve the performance of these models, future studies should focus on using machine learning techniques in image analysis.

Spontaneous ureteral stone passage: a novel and comprehensive nomogram

BACKGROUND

Ureteral stones pose a high economic and medical burden among Emergency Department (ED) admissions. Management strategies vary from expectant therapy to surgical interventions. Since predictors of ureteral spontaneous stone passage (SSP) are still not well understood, we sought to create a novel nomogram to guide management decisions.

METHODS

Charts were retrospectively reviewed for patients who presented to our institution's ED with non-febrile renal colic and received a radiological diagnosis of ureteral stone ≤10 mm. Demographic, clinical, laboratory, and non-contrast CT data were collected. This novel nomogram incorporates the serum neutrophil-to-lymphocyte ratio (NLR) as a potential predictor of SSP. The model was derived from a multivariate logistic regression and was validated on a different cohort. A receiver operator characteristic (ROC) curve was constructed and the area under the curve (AUC) was computed.

RESULTS

A total of 1186 patients presented to our ED between January 2010 and October 2018. We randomly divided our population into a derivation and validation cohort in one to five ratio. A stone size ≥7 mm was the strongest predictor of SSP failure; OR=9.47; 95% CI: 6.03-14.88. Similarly, a NLR≥3.14 had 2.17; (1.58-2.98) the odds of retained stone. SSP failure was also correlated with proximal position, severe hydronephrosis, and leukocyte esterase ≥75, P=0.02, P=0.05, and P=0.006, respectively. The model had an AUC of 0.804 (0.776-0.832). The nomogram was also used to compute the risk of SSP failure (AUC 0.769 [0.709-0.829]).

CONCLUSIONS

Our novel nomogram can be used as a predictor for SSP and can be used clinically in decision making.

Clinical and Radiological Predictors of Early Intervention in Acute Ureteral Colic

PURPOSE

Acute ureteric colic (AUC) is generally one of the most common reasons for emergency department attendance. Expectant management is recommended in non-complicated ureteral calculi. However, data regarding the optimal duration of observation or indications of early intervention (EI) are not well understood. This article describes the clinical and radiological factors that promote EI in AUC.

PATIENTS AND METHODS

This was an observational and retrospective cohort study. Patients with AUC diagnosed based on non-contrast computerized tomography (NCCT) between 2019 and 2020 were enrolled in the study. These patients were classified into two main categories: spontaneous passage of stone (SSP) and EI. In addition, a comparative analysis was performed to identify clinical and radiological variables that promote EI.

RESULTS

One-hundred and sixty-one patients were included. High WBCs are associated with a significant increase in EI. Forty-three percent (n=37) of patients with serum WBCs higher than 10 had an EI, while 23% had SSP (n=17;p<0.001). High CRP level is also significantly associated with EI (n=36; 86%; p<0.001). Upper and middle ureteral calculi are statistically associated with EI (n=54; 62%) in comparison to the SSP cohort (n=22; 30%;p<0.001). EI is also linked to the maximal length of ureteric calculi (MCL) of 9 mm (6-13mm), and HU density of stone of 700 (430-990) H.U (p<0.001). Ureteric stone volume of 0.2 (0.06-0.3) cm³ is significantly associated with EI (p<0.001). Ureteral wall thickness of 3 (2-3 mm), the presence of extrarenal pelvis (n=20; 23%), and AP diameter of renal pelvis 18 (13-28 mm) are all significantly associated with a higher rate of EI (p<0.001). Multiple binary logistic regression analysis showed that MCL is the strongest predictor of EI.

CONCLUSION

MCL is an independent and robust predictor of EI in AUC. Biochemical variables and radiological characteristics can also act as an adjunct to promote EI.

Hounsfield unit and its correlation with spontaneous expulsion of lower ureteric stone

Background:

Hounsfield unit (HU) is the measure of stone density, and is utilized in the predetermination of type of stone. The purpose of this study was to identify some factors in noncontrast computed tomography (NCCT) of kidney, ureter, and bladder (KUB) that are easily extractable and can be used to determine the outcome of expectant management.

Methods:

All patients 18–50 years of age who presented with flank pain and diagnosed as having lower ureteric calculi of size 5–10 mm by NCCT KUB were included in the study. HU of stone was calculated from the mean HU at three different regions of interest. We prescribed tamsulosin for 4 weeks as medical expulsive therapy. We divided the patients into two groups: group A included patients with successful expulsion of stone, and group B included patients who failed to pass stone. We compared age, gender, laterality, stone size in axial and coronal section of NCCT, HU of stone, blood urea, creatinine, and renal parenchymal thickness.

Results:

A total of 180 patients with lower ureteric calculus were included in the study. The mean age of patients was 34 years, with male:female ratio of 2.3:1. Of these 180 patients, 119 (66%) successfully expelled the stone and were included in group A, with the remaining 61 (34%) forming group B. In univariate analysis, longitudinal diameter of stone (p < 0.001), transverse diameter of stone (p < 0.001) and high HU (p < 0.001) were significantly associated with failure of expulsion. However, in multivariate analysis only longitudinal diameter of stone (p < 0.001) differed significantly among groups. Differences in HU (p = 0.179) and transverse diameter of stone (p = 0.108) did not reach significance level.

Conclusions:

Lower ureteric calculi are definitely amenable to conservative management. Longitudinal diameter of stone can be a useful parameter; however, HU and its derivatives cannot be used as a predictor of outcome.

Inflammatory serum markers predicting spontaneous ureteral stone passage

INTRODUCTION

Ureteral stones pose a high economic and medical burden among Emergency Department (ED) admissions. Management strategies vary from expectant therapy to surgical interventions. However, predictors of spontaneous ureteral stone passage are still not well understood. We aim to explore the role of neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte (PLR) ratios in the spontaneous ureteral stone passage (SSP).

METHODS

Chart review was done for 619 patients who presented to our institution's ED with non-febrile renal colic and received a radiological diagnosis of ureteral stone of less than 10 mm. Demographic, clinical, laboratory, and radiological data were collected. The Linear-by-Linear Association test was used to look at the trend among the NLR and PLR quartiles and other demographic variables. Univariate analysis was run for the collected variables. Then, a hierarchal backward multivariate logistic regression was run for each of NLR and PLR variables. To validate the results, bootstrapping was undertaken for each model.

RESULTS

NLR between 2.87 and 4.87 had odds ratio (OR) 2.96 (95% CI 1.80-5.49) and an NLR > 4.87 had 3.63 (2.04-6.69) the odds of retained ureteral stone. A PLR between 10.42 and 15.25 and a PLR > 15.25 had 3.28 (1.79-6.19) and 3.84 (2.28-7.12) the odds of failed SSP, respectively. Other significant variables in the two models are diabetes, urine leukocyte esterase > 10 white blood cell/μl, moderate-to-severe hydronephrosis, and stone size.

CONCLUSION

NLR and PLR are inversely associated with SSP of ureteral stones. In adjunct with other indicators, NLR and PLR are inflammatory markers that could be used in the clinical decision of ureteral stone management.

Factors associated with spontaneous stone passage in a contemporary cohort of patients presenting with acute ureteric colic: results from the Multi-centre cohort study evaluating the role of Inflammatory Markers In patients presenting with acute ureteric Colic (MIMIC) study

OBJECTIVES

To assess the relationship of white blood cell count (WBC) and other routinely collected inflammatory and clinical markers including stone size, stone position, and medical expulsive therapy use (MET), with spontaneous stone passage (SSP) in a large contemporary cohort of patients with acute ureteric colic, as there are conflicting data on the role of WBC and other inflammatory markers in SSP in patients with acute ureteric colic.

PATIENTS AND METHODS

Multicentre retrospective cohort study coordinated by the British Urology Researchers in Surgical Training (BURST) Research Collaborative at 71 secondary care hospitals across four countries (UK, Republic of Ireland, Australia, and New Zealand). In all, 4170 patients presented with acute ureteric colic and a computed tomography confirmed single ureteric stone. Our primary outcome measure was SSP, as defined by the absence of need for intervention to assist stone passage (SP). Multivariable mixed effects logistic regression was used to explore the relationship between key patient factors and SSP.

RESULTS

In all, 2518 patients were discharged with conservative management and had further follow-up with a SSP rate of 74% (n = 1874/2518). Sepsis after discharge with conservative management was reported in 0.6% (n = 16/2518). On multivariable analysis neither WBC, neutrophils count, nor C-reactive protein (CRP) predicted SSP, with an adjusted odds ratio (OR) of 0.97 (95% confidence interval [CI] 0.91-1.04, P = 0.38), 1.06 (95% CI 0.99-1.13, P = 0.1) and 1.00 (95% CI 0.99-1.00, P = 0.17), respectively. MET also did not predict SSP (adjusted OR 1.11, 95% CI 0.76-1.61). However, stone size and stone position were significant predictors. SSP for stones <5 mm was 89% (95% CI 87-90) compared to 49% (95% CI 44-53) for stones ≥5-7 mm, and 29% (95% CI 23-36) for stones >7 mm. For stones in the upper ureter the SSP rate was 52% (95% CI 48-56), middle ureter was 70% (95% CI 64-76), and lower ureter was 83% (95% CI 81-85).

CONCLUSION

In contrast to the previously published literature, we found that in patients with acute ureteric colic who are discharged with initial conservative management neither WBC, neutrophil count, nor CRP, helps determine the likelihood of SSP. We also found no overall benefit from the use of MET. Stone size and position are important predictors and our present findings represent the most comprehensive SP rates for each millimetre increase in stone size from a large contemporary cohort adjusting for key potential confounders. We anticipate that these data will aid clinicians managing patients with acute ureteric colic and help guide management decisions and the need for intervention.

Association of spontaneous expulsion with C-reactive protein and other clinico-demographic factors in patients with lower ureteric stone

The purpose of our study is to analyze the definitive relation of C-reactive protein (CRP) and other factors with the spontaneous stone passage in patients with distal ureteric calculus of 5-10 mm and to calculate the risk of failure of expectant management in patients. 185 patients of ureteric colic, who were subjected to medical expulsive therapy (MET), were included prospectively from August 2016 to May 2018 and followed up for 4 weeks. Patients were divided into two groups. Group A included successful spontaneous passage patients and group B included failure in the same. The parameters analyzed were age, gender, longitudinal and transverse diameter of stone, CRP, total leucocyte count, ureteric diameter and hydroureteronephrosis (HUN). We performed univariate and multivariate analysis. Receiver operating characteristics curve was used to determine the cutoff value for significantly associated variables. 122 (65.90%) and 63 (34.10%) patients were included in group A and B, respectively. In univariate analysis, CRP, longitudinal and transverse diameter of stone, HUN, proximal and distal ureteric diameters were statistically significant. However, in multivariate analysis, only negative CRP (p = 0.002), smaller longitudinal diameter of stone (p < 0.001) and absence of HUN (p = 0.005) were significantly associated with successful expulsion. Cutoff for CRP was 0.41 mg/dl and longitudinal diameter was 6.7 mm. The success rate in the group of patients with no risk factor was 96.7% and with all three risk factors was 16.7%. Patients with a longitudinal diameter of stone > 6.7 mm, HUN, and CRP > 0.41 mg/dl should be considered for early intervention. The success rate of MET can be increased to 86% after exclusion of patients with all three risk factors.

Assessment of factors affecting the spontaneous passage of lower ureteric calculus on the basis of lower ureteric calculus diameter, density, and plasma C- reactive protein level

Introduction:

The study aimed to evaluate the factors which affect the spontaneous passage of lower ureteric calculus on the basis of noncontrast computed tomography kidneys, ureters, and bladder (NCCT KUB) stone diameter, stone density, and plasma C-reactive protein (CRP) level.

Materials and Methods:

We conducted a prospective study of 200 patients with lower ureteric calculus 5–10 mm in size, from October 2015 to December 2016. All patients underwent NCCT KUB region with a 5 mm axial and reformatted coronal section. Edema just above the calculus and rim sign at the level of calculus and density of calculus is evaluated. Only scan with isolated, unilateral, solitary ureteric calculus was included in the final analysis and monitored up to 4 weeks, and plasma CRP is estimated in all patients to determine the clinical outcome.

Results:

A total of 200 patients (145 males, 55 females; mean age ± standard deviation, 34.73 ± 10.29) were included in the study. Lower ureteric calculus between 5–7 mm passed in 70% and 7–10 mm passed in 40%. There was 18% underestimation of maximum stone diameter in axial plane as compared to coronal plane. For spontaneous passage of calculus, craniocaudal (CC) diameter is more reliable then axial in NCCT. Rim sign and edema is absent in 64% of those passed spontaneous calculus. CRP level more than 2.45 mg/dl has low spontaneous expulsion rate. The stone with different HU passes through the ureter with same rate.

Conclusion:

Plasma CRP level and CC diameter and absence of rim sign on NCCT KUB are more reliable factors then density for spontaneous passage of ureteric calculus.

A multi-centre cohort study evaluating the role of inflammatory markers in patient's presenting with acute ureteric colic (MIMIC)

Background

Spontaneous Stone Passage (SSP) rates in acute ureteric colic range from 47 to 75%. There is conflicting evidence on the role of raised inflammatory markers in acute ureteric colic. The use of an easily applicable biomarker that could predict SSP or need for intervention would improve the management of obstructing ureteric stones. Thus, there is a need to determine in an appropriately powered study, in patients who are initially managed conservatively, which factors at the time of acute admission can predict subsequent patient outcome such as SSP and the need for intervention. Particularly, establishing whether levels of white cell count (WBC) at presentation are associated with likelihood of SSP or intervention may guide clinicians on the management of these patients’ stones.

Design

Multi-center cohort study disseminated via the UK British Urology Researchers in Surgical Training (BURST) and Australian Young Urology Researchers Organisation (YURO).

Primary research question

What is the association between WBC and SSP in patients discharged from emergency department after initial conservative management?

Patient population

Patients who have presented with acute renal colic with CT KUB evidence of a solitary ureteric stone. A minimum sample size of 720 patients across 15 centres will be needed.

Hypothesis

A raised WBC is associated with decreased odds of spontaneous stone passage.

Primary outcome

The occurrence of SSP within six months of presentation with acute ureteric colic (YES/NO). SSP was defined as absence of need for intervention to assist stone passage.

Statistical analysis plan

A multivariable logistic regression model will be constructed, where the outcome of interest is SSP using data from patients who do not undergo intervention at presentation. A random effect will be used to account for clustering of patients within hospitals/institutions. The model will include adjustments for gender, age as control variables.

Significance of Neutrophil-to-Lymphocyte Ratio as a Novel Indicator of Spontaneous Ureter Stone Passage

PURPOSE

Stone size and location are generally considered the most important factors associated with spontaneous ureter stone passage (SSP). Several parameters related to inflammatory changes have been identified as predictors associated with SSP. Our aim was to investigate the predictive role of neutrophil-to-lymphocyte ratio (NLR) for SSP.

MATERIALS AND METHODS

A retrospective review was performed on 131 patients who were referred to the urology outpatient clinic and diagnosed with unilateral ureteral stones at our emergency department between July 2016 and December 2016. The presence of ureteral stones was confirmed with non-contrast-enhanced computed tomography (NCCT) for all patients. SSP was confirmed with either the patient collecting the stone during urination or by NCCT performed at 3 weeks from the first stone episode. Physical examination, urinalysis, complete blood count, serum chemistry and inflammatory markers, plain radiographs, and NCCT at initial presentation were reviewed to analyze predictors of future SSP.

RESULTS

Of 113 patients included for analysis, 90 (79.6%) passed their stones spontaneously. The SSP rates within 3 weeks according to the stone's size (5-10 mm and ≤5 mm) were 62.2% and 88.2%, respectively. A lower stone location [odds ratio (OR), 11.54; p=0.001], smaller stone size (≤5 mm) (OR, 8.16; p=0.001), and NLR (<2.3) (OR, 9.03; p=0.003) were independent predictors of SSP.

CONCLUSION

Low NLR (<2.3) may predict SSP in patients with ureter stones ×1.0 cm in size. Our results suggest that ureteral inflammation plays an important role in SSP. Early intervention may be considered for patients presenting with high NLR (≥2.3).

Size matters: The width and location of a ureteral stone accurately predict the chance of spontaneous passage

Objectives

To determine how to most accurately predict the chance of spontaneous passage of a ureteral stone using information in the diagnostic non-enhanced computed tomography (NECT) and to create predictive models with smaller stone size intervals than previously possible.

Methods

Retrospectively 392 consecutive patients with ureteric stone on NECT were included. Three radiologists independently measured the stone size. Stone location, side, hydronephrosis, CRP, medical expulsion therapy (MET) and all follow-up radiology until stone expulsion or 26 weeks were recorded. Logistic regressions were performed with spontaneous stone passage in 4 weeks and 20 weeks as the dependent variable.

Results

The spontaneous passage rate in 20 weeks was 312 out of 392 stones, 98% in 0–2 mm, 98% in 3 mm, 81% in 4 mm, 65% in 5 mm, 33% in 6 mm and 9% in ≥6.5 mm wide stones.

The stone size and location predicted spontaneous ureteric stone passage. The side and the grade of hydronephrosis only predicted stone passage in specific subgroups.

Conclusion

Spontaneous passage of a ureteral stone can be predicted with high accuracy with the information available in the NECT. We present a prediction method based on stone size and location.

Key Points

• Non-enhanced computed tomography can predict the outcome of ureteral stones.

• Stone size and location are the most important predictors of spontaneous passage.

• Prediction models based on stone width or length and stone location are introduced.

• The observed passage rates for stone size in mm-intervals are reported.

• Clinicians can make better decisions about treatment.

External validation of the STONE score and derivation of the modified STONE score

OBJECTIVE

The STONE score is a clinical prediction rule for the presence of uncomplicated ureter stones with a low probability of acutely important alternative findings. This study performed an external validation of the STONE score, focusing on the Korean population, and a derivation of the modified STONE score for better specificity and sensitivity.

METHODS

We retrospectively reviewed medical records of patients complaining of flank pain at a single emergency department from January 2013 to December 2014. Patients were categorized into 3 groups according to their STONE score. The prevalence of ureter stones and other alternative findings were calculated in each group. We derived a modified STONE score based on a multivariable analysis and performed an interval validation.

RESULTS

From the 700 patients included in the analysis, 555 patients (79%) had a ureter stone. The area under the receiver operating characteristic curve of the STONE score was 0.92. The sensitivity of the high stone score was 0.56. In the modified STONE score, nausea, vomiting, and racial predictors were substituted by C-reactive protein and previous stone history. The area under the receiver operating characteristic curve and sensitivity of the modified STONE score in the internal validation group significantly increased to 0.94 and 0.80, respectively.

CONCLUSION

The STONE score can be used to predict a ureter stone with a low probability of other alternative findings. The modified STONE score might increase the diagnostic performance in suspicious urinary stone cases.

KEY POINTS

We performed external validation of the STONE score and derivation of the modified STONE score. This scoring system could help the clinicians with radiation reducing decision making.

Predictive Factors for Spontaneous Stone Passage and the Potential Role of Serum C-Reactive Protein in Patients with 4 to 10 mm Distal Ureteral Stones: A Prospective Clinical Study

PURPOSE

We investigated possible predictive factors for spontaneous stone passage and the potential role of serum C-reactive protein and white blood count in patients with 4 to 10 mm distal ureteral stones.

MATERIALS AND METHODS

A total of 251 patients who presented with renal colic secondary to distal ureteral stone were included in study. Patients were grouped according to spontaneous stone passage. Serum C-reactive protein, white blood count and other possible factors were investigated for their potential predictive value for spontaneous stone passage at a followup of 5 weeks. Potential predictive factors for spontaneous stone passage were evaluated with univariate and multivariate analyses. ROC curve analysis was performed to find an optimal cutoff value for serum C-reactive protein according to spontaneous stone passage. Statistical significance was considered at p <0.05.

RESULTS

Spontaneous stone passage was observed in 135 patients (53.8%) in group 1 while 116 (46.2%) in group 2 did not expel the stone spontaneously. Median stone size was 5.7 mm. Stone size, serum C-reactive protein and white blood count were significantly higher in group 2 than in group 1. The number of patients with hydronephrosis and the number with spontaneous stone passage history were significantly lower in group 2 compared to group 1. The cutoff value of serum C-reactive protein provided by ROC analysis was 0.506 mg/l. Time to spontaneous stone passage was significantly higher in patients with serum C-reactive protein above the threshold and in patients with ureteral stones greater than 6 mm.

CONCLUSIONS

Stone size, previous spontaneous passage, hydronephrosis, serum C-reactive protein and white blood count can be used to predict spontaneous stone passage in patients with 4 to 10 mm distal ureteral stones. A serum C-reactive protein level of 0.506 mg/l can serve as a cutoff value to predict spontaneous stone passage.

Factors predicting the spontaneous passage of a ureteric calculus of ⩽10 mm

Objective

To evaluate the outcome of the expectant management of ureteric stones and to determine the factors predictive of the spontaneous passage of stones.

Patients and methods

We retrospectively reviewed the medical records of patients who had ureteric stones of ⩽10 mm and who were treated conservatively at our institutions during the period 2008–2013. The stone-passage rate and time, and different clinical, laboratory and radiological variables, were analysed.

Results

In all, 163 patients with ureteric stones were enrolled in the study, of whom 127 (77.9%) passed their stones spontaneously, with a mean (SD) passage time of 24.0 (8.09) days. The cumulative stone-passage rate was 1.6%, 15%, 41.7%, 72.4%, 89.8% and 98.4% at 7, 14, 21, 28, 35 and 42 days from the first presentation, respectively. Patients with a high pain-scale score, stones of ⩽5 mm, a lower ureteric stone, a high white blood cell count and those with absent computed tomography (CT) findings of perinephric fat stranding (PFS) and tissue-rim sign (TRS) had a higher likelihood of spontaneous stone passage. Patients with stones of ⩽5 mm, stones in the lower ureter and those with no PFS had a shorter spontaneous passage time. In a multivariate analysis the absence of PFS and TRS were the only significant predictors for spontaneous stone passage (P < 0.001 and 0.002, respectively).

Conclusions

The spontaneous ureteric stone-passage rate and time varies with different factors. The absence of CT findings of PFS and TRS are significant predictors for stone passage, and should be considered when choosing the expectant management.