Role of white blood cell and neutrophil counts in predicting spontaneous stone passage in patients with renal colic

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.

The role of serum and urinary markers in predicting obstructing ureteral stones and reducing unjustified non-contrast computerized tomographic scans in emergency departments

INTRODUCTION

The reported yield of non-contrast computed tomography (NCCT) in assessing flank pain and obstructive urolithiasis (OU) in emergency departments (EDs) is only ~ 50%. We investigated the potential capability of serum and urinary markers to predict OU and improve the yield of NCCT in EDs.

METHODS

All consecutive ED patients with acute flank pain suggestive of OU and assessed by NCCT between December 2019 and February 2020 were enrolled. Serum white blood cells (WBC), C-reactive protein (CRP) and creatinine (Cr) levels, and urine dipstick results were analyzed for association with OU, and unjustified NCCT scan rates were calculated.

RESULTS

NCCTs diagnosed OU in 108 of the 200 study patients (54%). The median WBC, CRP, and Cr values were 9,100/µL, 4.3 mg/L, and 1 mg/dL, respectively. Using ROC curves, WBC = 10,000/µL and Cr = 0.95 mg/dl were the most accurate thresholds to predict OU. Only WBC ≥ 10,000/µL (OR = 3.7, 95% CI 1.6-8.3, p = 0.002) and Cr ≥ 0.95 mg/dl (OR = 5, 95% CI 2.3-11, p < 0.001) were associated with OU. Positive predictive value and specificity for detecting OU among patients with combined WBC ≥ 10,000 and Cr ≥ 0.95 were 83% and 89%, respectively. Patients negative to the serum markers criteria underwent significantly more unjustified NCCTs (p = 0.03). The negative predictive value of the serum criteria for justified NCCT scanning was 81%.

CONCLUSIONS

WBC and Cr may be valuable serum markers in predicting OU among patients presenting to EDs with acute flank pain. They may potentially reduce the number of unjustified NCCT scans in the ED setting.

Clinical Score Application for Abdominopelvic Computed Tomography Used in the Diagnosis of Renal Colic Patients

Background To develop risk scoring for the use of computed tomography (CT) imaging using the visual analog scale (VAS), physical examination, and laboratory findings of renal colic patients admitted to the emergency department (ED).

Materials and Methods This is prospective observational study. Among the patients who presented to the ED with abdominal or flank pain, patients who were scheduled for CT imaging for urolithiasis were included in the study. The mean VAS pain scores, physical examination findings, laboratory parameters, and macroscopic and microscopic values in urinalysis were compared between the two groups with and without stones on CT.

Results Of the 196 urolithiasis patients included in the study, 165 had ureteral stones, 76 had renal stones, and 45 had renal and ureteral stones. While the difference between the urine erythrocyte averages of the two groups was borderline significant (p = 0.04), there was a high difference between the urinary hemoglobin amounts (p < 0.001). In patients with urinary system stone disease, hydronephrosis, and ureteral dilatation, hemoglobin ++ and above were more significant (p < 0.001). For ureteral stones, pain intensity increased as the size increased (r = 0.34 p < 0.001). White blood cells > 10,000 103/mL, and C-reactive protein (CRP) ≤ 5 mg/L were more significant in patients with acute renal colic.

Conclusions Although we cannot develop a clinical scoring system for renal colic patients, the meaningful results we found for urinary stone disease can be used in a newly developed scoring system. It can be used in new scoring systems in the ED using a high VAS score, presence and amount of urine hemoglobin, CRP) ≤ 5 mg/L, and creatinine value.

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.

•

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

•

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

•

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.

Nomogram predicting the probability of spontaneous stone passage in patients presenting with acute ureteric colic

OBJECTIVES

To develop a nomogram that could predict spontaneous stone passage (SSP) in patients presenting with acute ureteric colic who are suitable for conservative management.

SUBJECT/PATIENTS

A 2517 patient dataset was utilised from an international multi-centre cohort study (MIMIC, A Multi-centre Cohort Study Evaluating the role of Inflammatory Markers In Patients Presenting with Acute Ureteric Colic) of patients presenting with acute ureteric colic across 71 secondary care hospitals in the United Kingdom, Ireland, Australia, and New Zealand. Inclusion criteria mandated a non-contrast CT-KUB.

METHODS

SSP was defined as the 'absence of the need for intervention'. The model was developed using logistic regression and backwards selection (to achieve lowest AIC) in a subset from 2009-2015 (n=1728) and temporally validated on a subset from 2016-2017 (n=789).

RESULTS

Of the 2517 patients, 1874 had SSP (74.5%). Mean age (±[SD]) was 47 (±14.7) years and 1892 were male (75.2%). At the end of the modelling process, gender: male (OR 0.8, 95%CI 0.64-1.01, p=0.07), neutrophil count (OR 1.03, 95%CI 1.00-1.06, p = 0.08), hydronephrosis (OR 0.79, 95%CI 0.59-1.05, p=0.1), hydroureter (OR 1.3, 95%CI 0.97-1.75, p =0.08), stone size >5-7mm (OR 0.2, 95%CI 0.16-0.25, p<0.0001), stone size >7mm (OR 0.11, 95%CI 0.08-0.15, p<0.001), middle ureter stone position (OR 0.59, 95%CI 0.43-0.81, p=0.001), upper ureter stone position (OR 0.31, 95%CI 0.25-0.39, p<0.001) ), medical expulsive therapy use (OR 1.36, 95%CI 1.1 - 1.67, p = 0.001), oral NSAID use (OR 1.3, 95%CI 0.99 - 1.71, p=0.06), and rectal NSAID use (OR1.17, 95%CI 0.9 - 1.53, p=0.24) remained. Concordance-statistic (C-statistic) was 0.77 (95%CI 0.75 - 0.80) and a nomogram was developed based on these.

CONCLUSION

The presented nomogram is available to use as an online calculator via www.BURSTurology.com and could allow clinicians and patients to make a more informed decision on pursuing conservative management versus early intervention.

EFFICACY OF DOXAZOSIN VERSUS TAMSULOSIN IN LOWER URETERIC STONE EXPULSION IN ADULT POPULATION OF DISTRICT DERA ISMAIL KHAN, PAKISTAN

Background: Urolithiasis is the third common disease of the urinary tract after UTIs and pathological diseases of the prostate. The objective of this study was to compare the efficacy of doxazosin versus tamsulosin in lower ureteric stone expulsion in adult population of District Dera Ismail Khan, Pakistan.Materials Methods: This non-randomized control trial was conducted in the Department of Urology, Gomal Medical College, Dera Ismail Khan, Pakistan from February 2020 to December 2020. The 252 patients included in our study were divided in to two groups. The patients in experimental group received Tab. doxazosin 4 mg daily for 4 weeks and Tab. diclofenac sodium 50 mg B.D for 5 days and then on need basis. The patients in control group received Cap. tamsulosin 0.4 mg daily for 4 weeks and similarly Tab. diclofenac sodium 50 mg as in experimental group. All the patients were followed regularly for expulsion of ureteric stones for four weeks. Sex, age and stone size were matching, while stone expulsion was a research variable. Hypothesis was verified by McNemar chi-square test.Results: Out of 252 patients, 113 (89.68%) patients in experimental group, while 77 (61.11%) patients in control group passed the stones. There was statistically significant difference in efficacy in doxazosin group as compared to tamsulosin group (p-value=.0001).Conclusion: The use of doxazosin as the medical expulsion therapy for the lower ureteric stone proved to be more effective as compared to tamsulosin as demonstrated by our results.

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.

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.

Can serum procalcitonin levels be useful in predicting spontaneous ureteral stone passage?

Background

Medical expulsive therapy (MET) is recommended for ureteral stones when there is no indication for interventional treatment. Spontaneous passage (SP) may not always be perceived in patients undergoing MET. We aimed to demonstrate the effects of inflammatory factors on spontaneous ureteral stone passage in patients undergoing MET.

Methods

Our study was conducted between August and November, 2016, in healthy volunteers and patients with a single distal ureteral stone between 5 and 10 mm in diameter and no indications for interventional therapy. Blood and urine samples from all patients and healthy volunteers were tested. The patients were followed up every 2 weeks for 1 month unless emergency situations appeared. Patients with stone-free status at follow-up were concluded to have achieved complete stone passage [SP(+)], and failure [SP(−)] was concluded if the patient had not passed the stone by the end of the study. Blood samples of the patients and the control group were analyzed, recording WBC (white blood cell), CRP (c-reactive protein), SED (sedimentation), MPV (mean platelet volume), NLR (neutrophil-to-lymphocyte ratio), and serum procalcitonin levels. Abnormalities in urine samples were recorded. All patients received diclofenac sodium 75 mg/day, tamsulosin 0.4 mg/day, and at least 3 l/day fluid intake. Patients were followed for a month with kidney, ureter, bladder (KUB) plain films, ultrasonography (USG), and unenhanced abdominal CT scans while undergoing MET. Comparative statistical analyses were performed between the SP(+) and SP(−) groups.

Results

The procalcitonin levels of the SP(−) group were significantly higher (207 ± 145.1 pg/ml) than in the SP(+) group (132.7 ± 28.1 pg/ml) (p = 0.000). The leucocyturia rate of the SP(−) group was significantly higher than in the SP(+) group (p = 0.004). Based on the ROC curve analysis, 160 pg/ml (86.7% sensitivity, 70.8% specificity, p < 0.001; AUC: 0.788 95% CI (0.658–0.917) was identified as the optimal cut-off value for procalcitonin. In logistic regression analysis, a significant efficacy of procalcitonin and leucocyturia was observed in the univariate analysis on spontaneous passage. In the multivariate analysis, significant independent activity was observed with procalcitonin. (p < 0.05).

Conclusion

Our findings suggest that high procalcitonin levels and the presence of leucocyturia have a strong negative effect on SP of ureteral stones between 5 and 10 mm in diameter. This relationship can be explained by stone impaction, possibly caused by increased mucosal inflammation.

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.

Ureteral wall thickness as a significant factor in predicting spontaneous passage of ureteral stones of ≤ 10 mm: a preliminary report

PURPOSE

To evaluate the clinical significance of ureteral wall thickness (UWT) for predicting spontaneous passage (SP) of uncomplicated ureteral stones of ≤ 10 mm.

METHODS

We retrospectively reviewed 418 patients with a diagnosis of uncomplicated ureteral stones who presented to Kori Hospital from 2011 to 2018. The maximum stone diameter and UWT at the stone site were measured from axial computed tomography images. Clinical predictors of 4-week SP were assessed using univariate and multivariate analyses. Receiver operating characteristic (ROC) curve analysis was applied to evaluate the accuracy of factors in predicting SP of ureteral stones.

RESULTS

Of the 418 patients, 202 (48.3%) spontaneously passed their stones within 4 weeks of their initial visit. Multivariate analysis showed that stone location, stone size, and UWT (odds ratio, 0.40; P < 0.001) were independent predictors of 4-week SP. ROC analysis showed that 2.71 mm was the optimal cut-off value for UWT, with a predictive accuracy of 0.83. Low UWT had a significantly higher 4-week SP rate than high UWT (76.4% vs. 14.7%, respectively; P < 0.001). In addition, high UWT was associated with a higher risk of stone-related complications within 4 weeks compared with low UWT (16.4% vs. 7.2%, respectively; P = 0.0044).

CONCLUSIONS

UWT can serve as a potential predictive factor for 4-week SP and may help physicians to select patients who require immediate interventions among those with ≤ 10-mm ureteral stones.

Prospective Evaluation of Predictive Parameters for Urinary Tract Infection in Patients with Acute Renal Colic

BACKGROUND

Acute renal colic (ARC) is an emergency that can mostly be treated conservatively, but can be life threatening in combination with urinary tract infection (UTI). Assessment for infection includes white blood cell (WBC) count and C-reactive protein (CRP), but these parameters are often unspecifically elevated and might lead to antibiotic over-therapy. In times of increasing antibiotic resistance, however, unnecessary antibiotic therapy should be avoided.

OBJECTIVES

The goal of the study was to investigate the prevalence of UTI proven by urine culture (UC) in patients with ARC and to identify predictive factors in the emergency setting.

PATIENTS AND METHODS

We prospectively enrolled 200 consecutive patients with ARC and evaluated blood test results, urinalysis, UC, symptoms suspicious for UTI, and time between symptom onset and admission, as well as body temperature. Logistic regression analyses were performed to identify predictive factors.

RESULTS

There were 196 patients eligible for statistical analysis. UTI proven by positive UC was detected in 26 patients (13%). On multivariate logistic regression analysis, suspicious urinalysis (positive nitrite or bacteria > 20/high-power field [hpf] or WBC > 20/hpf), patient age ≥ 54 years and CRP ≥ 1.5 mg/dL (fivefold increase) were significant predictors for the presence of UTI. Neither elevated WBC count nor typical UTI symptoms were associated with UTI.

CONCLUSIONS

Based on our results, a routine antibiotic prophylaxis in patients with ARC does not seem to be appropriate. Patient age and CRP can help to decide if antibiotic treatment might be indicated, even in case of a not clearly suspicious urinalysis.

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).

Transient renal impairment in the absence of pre-existing chronic kidney disease in patients with unilateral ureteric stone impaction

This study aims to describe the rate and characteristics of transient renal impairment in unilateral ureteric stone patients without chronic kidney disease (CKD) and to identify factors that may have influenced renal function of these patients. Unilateral ureteric stone patients who visited our hospital's emergency department from December, 2009 to December, 2015 were divided into two groups based on estimated glomerular filtration rate (eGFR): group I (patients with eGFR ≥ 60 ml/min/1.73 m²) and group II (eGFR < 60 ml/min/1.73 m²). A univariate comparison between groups I and II was performed. Multivariable logistic regression analysis was performed to determine factors that influenced renal function. There were 107 patients in group II, which constituted 5.6 % of the total patients. In the multivariable logistic regression analysis, age (p < 0.001, odds ratio [OR] = 1.069, confidence interval [CI] = 1.049-1.089), hypertension (p < 0.001, OR = 2.302, CI = 1.467-3.611), stone size (p = 0.001, OR = 1.141, CI = 1.057-1.231), white blood cell count (p = 0.001, OR = 1.132, CI = 1.055-1.215) and hematuria (p < 0.001, OR = 0.383, CI = 0.231-0.636) were found to be independent factors for renal impairment. Based on the results of this study, the rate of renal impairment was 6 % of the unilateral ureteric stone patients without pre-existing CKD. Age and hypertension were found to be independent factors for renal impairment; NSAIDs should be used cautiously or other agents for pain relief such as opioids should be considered in old aged patients with hypertension.

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.

Early hospital admission and treatment onset may positively affect spontaneous passage of ureteral stones in patients with renal colic

OBJECTIVE

To evaluate the impact of early hospital admission and onset of medical expulsive therapy (MET) in spontaneous passage of ureteral stones causing renal colic.

METHODS

We recruited 392 patients referred to the emergency room with symptoms of renal colic. All patients received standard MET of oral tamsulosin 0.4 mg at the time of diagnosis. In group A, patients who received MET in <2 hours from the symptom onset were included, whereas group B consisted of patients treated in >2 hours. The association of MET onset and stone-free rates after 6 weeks of follow-up was evaluated. Early MET onset predictive impact on spontaneous stone passage was evaluated as well.

RESULTS

The stone-free rate in group A and B patients was 71.2% and 59.7% (P=.018), respectively. A significant association was observed between spontaneous calculus elimination and stone size (P≤.001), location within the ureter (P=.007), and the interval between pain onset and pharmaceutical management (P=.018). Patients who received a late-onset MET had an increased risk to develop febrile upper urinary tract infection during the follow-up period (P=.040). In the multivariate analysis, size (P≤.001) and early therapy onset (P=.019) were statistically important predictors for stone-free status after the surveillance period.

CONCLUSION

Patients with renal colic who admitted to the emergency department earlier since symptom onset may have increased potential to be stone free during the surveillance period.

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

PURPOSE

A ureter obstruction caused by a ureteral stone results in inflammatory changes in the proximal submucosal layer and prevents the spontaneous passage of the ureteral stone. Accordingly, we analyzed the relationship between the spontaneous passage rates of ureteral stones less than 8 mm in size and serum C-reactive protein (CRP) levels and neutrophil percentages.

MATERIALS AND METHODS

A total of 187 patients who were diagnosed with ureteral stones less than 8 mm in size and were managed consecutively at Keimyung University Dongsan Medical Center from January 2001 to January 2011 were retrospectively analyzed. Ureteral stone removal was defined as no ureteral stone shown in an imaging test without any treatment for 8 weeks after diagnosis. The patients were divided into three groups according to the levels of serum CRP and into two groups according to neutrophil percentage. The associations between these factors and ureteral stone passage rates were then examined.

RESULTS

The ureteral stone passage rates of the low serum CRP level group, the medium serum CRP level group, and the high serum CRP level group were 94.1% (159/169), 70% (7/10), and 50.0% (4/8), respectively. The passage rates of ureteral stones in the group with a normal neutrophil percentage and in the group with a higher neutrophil percentage were 94.5% (121/128) and 83.1% (49/59), respectively (p=0.011).

CONCLUSIONS

Measuring serum CRP levels and neutrophil percentages in patients with small ureteral stones of less than 8 mm is useful in predicting whether the stone will be spontaneously passed. When the serum CRP level and neutrophil percentage of a patient are high, aggressive treatment such as extracorporeal shock wave lithotripsy should be considered.

Dual-energy CT for the evaluation of urinary calculi: image interpretation, pitfalls and stone mimics

Urolithiasis is a common disease with a reported prevalence between 4% and 20% in developed countries. Determination of urinary calculi composition is a key factor in preoperative evaluation, treatment, and stone recurrence prevention. Prior to the introduction of dual-energy computed tomography (DECT), available methods for determining urinary stone composition were only available after stone extraction, and thereby unable to aid in optimized stone management prior to intervention. DECT utilizes the attenuation difference produced by two different x-ray energy spectra to quantify urinary calculi composition as uric acid or non-uric acid (with likely further classification in the future) while still providing the information attained with a conventional CT. Knowledge of DECT imaging pitfalls and stone mimics is important, as the added benefit of dual-energy analysis is the determination of stone composition, which in turn affects all aspects of stone management. This review briefly describes DECT principles, scanner types and acquisition protocols for the evaluation of urinary calculi as they relate to imaging pitfalls (inconsistent characterization of small stones, small dual-energy field of view, and mischaracterization from surrounding material) and stone mimics (drainage devices) that may adversely impact clinical decisions. We utilize our clinical experience from scanning over 1200 patients with this new imaging technique to present clinically relevant examples of imaging pitfalls and possible mechanisms for resolution.