Factors Associated with Preventive Pharmacological Therapy Adherence among Patients with Kidney Stones

Casey A. Dauw, MD, Yooni Yi, MD, Maggie J. Bierlein, MS, Phyllis Yan, MS, Abdulrahman F. Alruwaily, MD, Khurshid R. Ghani, MD, J. Stuart Wolf, MD, Brent K. Hollenbeck, MD, MS, John M. Hollingsworth, MD, MS

Department of Urology, From the Divisions of Endourology and Health Services Research, University of Michigan Medical School




To determine adherence patterns for thiazide diuretics, alkali citrate therapy, and allopurinol, collectively referred to as preventive pharmacological therapy (PPT), amongst patients with kidney stones.

Materials and Methods

Using medical claims data, we identified adults diagnosed with kidney stones between 2002 and 2006. Through National Drug Codes, we determined those with one or more prescription fills for a PPT agent. We measured adherence to PPT [as determined by the proportion-of-days-covered (PDC) formula] within the first 6 months of starting therapy and performed multivariate analysis to evaluate patient factors associated with PPT adherence.


Among 7,980 adults with kidney stones who were prescribed PPT, less than one third (30.2%) were adherent to their regimen (indicated by PDC=80%). Among those on monotherapy, rates of adherence differed by the type of PPT agent prescribed: 42.5% for thiazides, 40.0% for allopurinol, and 13.4% for citrate therapy. Factors that were independently associated with lower odds of PPT adherence included combination therapy receipt, female gender, less generous health insurance, and residence in the South or Northeast. In contrast, older patients and those with salaried employment had a higher probability of PPT adherence.


Adherence to PPT is low. These findings help providers identify patients where PPT adherence will be problematic. Moreover, they suggest possible targets for quality improvement efforts in the secondary prevention of kidney stones.


Irreversible Renal Function Impairment due to Silent Ureteral Stones

Giovanni S. Marchini, Fábio Carvalho Vicentini, Manoj Monga, Fábio César Miranda Torricelli, Alexandre Danilovic, Artur Henrique Brito, Cesar Câmara, Miguel Srougi, Eduardo Mazzucchi

1 Section of Endourology, Division of Urology, Hospital das Clínicas, University of Sao Paulo Medical School, Sao Paulo, Brazil

2 Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio



to evaluate if renal function loss and hydronephrosis due to a silent ureteral stone might be reversed.


We prospectively selected patients with silent ureteral stones between Jan/06-Jan/14. A silent case was considered if there were no specific or subjective symptoms related to the ureteral stone. Patient, stone and kidney characteristics were evaluated preoperatively, three and twelve months postoperatively. Renal function was accessed in the same intervals with serum creatinine (sCr), glomerular filtration rate (GFR) and 99mTc-DMSA. Patients without complete pre and postoperative evaluation were excluded. Primary end-point was mid-term progress of global and ipsilateral renal function. Secondary end-points included the evaluation of renal and collecting system anatomy from diagnosis to 12 months after treatment. ANOVA with repeated measures and marginal homogeneity test were used to evaluate renal function and hydronephrosis progression.


Twenty-six patients met our inclusion criteria. Mean preoperative SCr and GFR was 1.24mg/dL and 72.5ml/min, respectively. At initial scintigraphy, mean renal function was 33.4%. Laser ureterolithotripsy was performed in 84.6% of cases and all patients were rendered stone free. Two patients (8%) developed ureteral stenosis. There was no difference regarding SCr (p=0.89), GFR (p=0.48) and renal function at scintigraphy (p=0.19) during follow-up. Hydronephrosis significantly improved from pre to three months postoperatively (p<0.0001), but not from three to twelve months (p=0.065).


Patients with silent ureteral stones present with significant impairment of ipsilateral renal function and hydronephrosis at diagnosis. On mid-term follow-up evaluation, renal function of the affected unit remains stable while hydronephrosis improves after treatment.

Urolithiasis. 2016 Apr 4. [Epub ahead of print]

Effect of anxiety and pain on success of shockwave lithotripsy (SWL) for treatment of proximal ureteral and renal pelvic stones.

Ucer O1, Ceylan Y2, Ekren F3, Ozan E4, Muezzinoglu T5.


The aim of this study is to evaluate the impact of anxiety and pain on success of shockwave lithotripsy (SWL) for treatment of proximal ureteral and renal pelvic stones smaller than 15 mm. One hundred thirty-two patients with proximal ureteral or renal pelvic stones <15 mm who were treated by a SWL and forty controls were enrolled in the study. State-trait anxiety inventory (STAI) was used to assess anxiety of the controls and patients (before every SWL session). Pains of the patients were measured by a visual analog scale (VAS) at three times (T) of the sessions (T11 at 11 kV, T15 at 15 kV and T end of treatment). The mean STAI scores of the patients at the first SWL session and controls were 40.61 ± 8.71 and 36.11 ± 8.18, respectively (p < 0.05). There was statistically positive moderate relationship between STAI and VAS scores at the first SWL session. The mean size of stone in men and women were 11.16 ± 2.88 and 11.00 ± 3.41, respectively (p = 0.88). In the first session, the mean STAI and VAS scores of the men were significantly lower than the women. The stone-free rate (SFR) of SWL was 72.7 % in this study. The SFR of SWL in the men and women were 78 and 64 %, respectively (p < 0.05). Our data showed that the severity of anxiety and pain in the women were higher than the men. SFR of SWL in the men was higher than the women. The severity of anxiety and pain in the patients may affect SFR of SWL.

Urolithiasis. 2016 Apr 1. [Epub ahead of print]

The influence of maternal and paternal history on stone composition and clinical course of calcium nephrolithiasis in subjects aged between 15 and 25.

Guerra A1,2, Ticinesi A3,4, Allegri F1,2, Nouvenne A1,2, Pinelli S2, Folesani G5, Lauretani F1, Maggio M1,2, Borghi L1,2, Meschi T1,2.

1Geriatric Rehabilitation Department, University-Hospital of Parma, Via Antonio Gramsci 14, 43126, Parma, Italy.

2Department of Clinical and Experimental Medicine, University of Parma, Via Antonio Gramsci 14, 43126, Parma, Italy.

3Geriatric Rehabilitation Department, University-Hospital of Parma, Via Antonio Gramsci 14, 43126, Parma, Italy.

4Department of Clinical and Experimental Medicine, University of Parma, Via Antonio Gramsci 14, 43126, Parma, Italy.

5INAIL-CERT Research Center at University of Parma, Via Antonio Gramsci 14, 43126, Parma, Italy.


Our aim was to compare the influence of maternal history of stones (MHS) and paternal history of stones (PHS) on composition of calculi and disease course in a group of patients with calcium nephrolithiasis (CN) aged between 15 and 25, the age range with the maximal influence of family history on disease expression. One-hundred thirty-five patients (68 F) with CN and one stone-forming parent were retrospectively selected from the database of our outpatient stone clinic, and categorized according to MHS or PHS. Data about stone disease course and composition of passed calculi, determined by chemical analysis or Fourier-transformed infrared spectrophotometry, were collected together with information on blood chemistry and 24-h urinary profile of lithogenic risk. The characteristics of disease course and stone composition were compared using logistic regression tests adjusted for age, sex, and BMI or analysis of covariance where appropriate. Patients with MHS (n = 46) had significantly higher urinary calcium/creatinine ratio and ammonium, a higher prevalence of urological treatments (57 vs 27 %, p < 0.001) and mixed calcium oxalate/calcium phosphate stone composition (69 vs 35 %, p = 0.002) than those with PHS. At multivariate logistic regression models, MHS was independently associated with urological treatments (OR 4.5, 95 %CI 1.9-10.7, p < 0.001) and the formation of calculi with mixed calcium oxalate/calcium phosphate composition (OR 5.8, 95 %CI 1.9-17.9, p = 0.002). The method of stone analysis did not affect this result. In conclusion, in subjects aged 15-25, MHS is associated with mixed calcium stones and with a higher risk for urological procedures, and should be, therefore, considered in the management of urolithiasis.

Management of lower pole renal stones: the devil is in the details

Berkan Resorlu, Yasar Issi, Kadir Onem, Cankon Germiyanoglu

Department of Urology, Ondokuz Mayis University, Faculty of Medicine, Samsun 55270, Turkey


Shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (MIP) are highly effective treatment options for lower pole stones up to 2 cm. Selecting the best treatment modality represents a controversial area in urology, because each treatment methods have their own advantages and disadvantages. Donaldson and co-workers have recently published a very comprehensive review and meta-analysis to compare the benefits and harms of SWL, RIRS and PNL techniques.

J Endourol. 2016 Apr 4. [Epub ahead of print]

Computed Tomography-based Novel Prediction Model for The Outcome of Shockwave Lithotripsy in Proximal Ureteral Stones

Park HS1, Gong MK2, Yoon CY3, Moon DG4, Cheon J5, Choi YD6.



Computed Tomography (CT) is one of the most commonly used diagnostic modalities for urinary stone disease. In the current study we developed a CT and clinical parameter-based prediction model for shockwave lithotripsy (SWL) outcome in proximal ureteral stones.


Data from 223 patients with single proximal ureteral stones treated with SWL between January 2009 and January 2015 were reviewed retrospectively. Clinical parameters including age, sex, body weight, and BMI (body mass index) were analyzed in combination with stone-related CT parameters (stone diameter, height, volume, location, Hounsfield units (HU), stone-to-skin distance (SSD)) and secondary signs (hydronephrosis, perinephric edema, and rim sign). Based on the cutoff values determined by c-statistics, a scoring system for the prediction of SWL outcome was developed.


The success rate was 65.9% (147 / 223), and in univariate analysis body weight, BMI, SSD (vertical, horizontal), HU, stone diameter, height, volume, and all secondary signs were significantly associated with the success of SWL. However, on multivariate analysis only BMI (OR = 1.322, CI 1.156-1.512, p = 0.00), stone diameter (OR = 1.397, CI 1.259-1.551, p = 0.00), and perinephric edema (grade 0-1 vs. 3-4, OR = 2.831, CI 1.032-7.764, p = 0.043) were independent predictors of SWL success. The prediction model based on the logistic regression analysis was as follows: SWL success = 1 / (1 + exp (-10.165 + 0.279  (BMI) + 0.334  (diameter) + 1.040 (perinephric edema)), having an AUC of 0.881. In the prediction model based on these parameters, scores of 0, 1, 2, and 3 correlated with SWL success rates of 98.5%, 65.7%, 31.4%, and 0%, respectively.


BMI, stone diameter, and perinephric edema were independent predictors of SWL outcome and a prediction model based on these parameters will facilitate decision-making for SWL in proximal ureteral stones.

Arab J Urol. 2016 Mar;14(1):12-7. doi: 10.1016/j.aju.2015.11.004. Epub 2015 Dec 31.

Silodosin vs tamsulosin in the management of distal ureteric stones: A prospective randomised study.

Elgalaly H1, Sakr A1, Fawzi A1, Salem EA1, Desoky E1, Shahin A1, Kamel M1.



To compare the efficacy of silodosin (8 mg) vs tamsulosin (0.4 mg), as a medical expulsive therapy, in the management of distal ureteric stones (DUS) in terms of stone clearance rate and stone expulsion time.


A prospective randomised study was conducted on 115 patients, aged 21-55 years, who had unilateral DUS of ⩽10 mm. Patients were divided into two groups. Group 1 received silodosin (8 mg) and Group 2 received tamsulosin (0.4 mg) daily for 1 month. The patients were followed-up by ultrasonography, plain abdominal radiograph of the kidneys, ureters and bladder, and computed tomography (in some cases).


There was a significantly higher stone clearance rate of 83% in Group 1 vs 57% in Group 2 (P = 0.007). Group 1 also showed a significant advantage for stone expulsion time and analgesic use. Four patients, two in each group, discontinued the treatment in first few days due to side-effects (orthostatic hypotension). No severe complications were recorded during the treatment period. Retrograde ejaculation was recorded in nine and three patients in Groups 1 and 2, respectively.


Our data show that silodosin is more effective than tamsulosin in the management of DUS for stone clearance rates and stone expulsion times. A multicentre study on larger scale is needed to confirm the efficacy and safety of silodosin.

Braz J Med Biol Res. 2016;49(4):e4878. doi: 10.1590/1414-431X20154878. Epub 2016 Mar 18.

Comparison of totally tubeless percutaneous nephrolithotomy and standard percutaneous nephrolithotomy for kidney stones: a randomized, clinical trial

Moosanejad N1, Firouzian A2, Hashemi SA3, Bahari M4, Fazli M4.


This study aimed to compare the totally tubeless percutaneous nephrolithotomy and standard percutaneous nephrolithotomy techniques regarding their rates of success and complications in patients with kidney stones. Patients were randomly assigned to two groups. Forty-four patients (24 men; mean age: 50.40±2.02 years) received totally tubeless percutaneous nephrolithotomy (PCNL; no nephrostomy catheter or ureteral catheter after PCNL) and 40 patients (18 men; mean age: 49.95±13.38 years) underwent standard PCNL (a nephrostomy catheter and ureteral catheter were used after PCNL). All surgeries were performed by one surgeon. Postoperative changes in hemoglobin, the blood transfusion rate, changes in creatinine levels, operation time, analgesic need, hospitalization time, and complication rate were compared between the groups. No significant differences were observed in age, gender, stone size, and surgery side between the groups (P<0.05). The operation time was significantly lower in the totally tubeless PCNL group than in the standard PCNL group (P=0.005). Pethidine requirements were significantly higher in the standard PCNL group than the totally tubeless PCNL group (P=0.007). Hospitalization time was significantly higher in the standard PCNL group than in the totally tubeless PCNL group (P<0.0001). The complication rate was 15% in the standard PCNL group and 9.1% in the totally tubeless PCNL group (P=0.73). The totally tubeless PCNL technique is safe and effective, even for patients with staghorn stones. This technique is associated with decreased pain, analgesic needs, and operative and hospitalization time. We believe that a normal peristaltic ureter is the best drainage tube.

Sci Rep. 2016 Apr 1;6:23988. doi: 10.1038/srep23988.

Stone heterogeneity index as the standard deviation of Hounsfield units: A novel predictor for shock-wave lithotripsy outcomes in ureter calculi.

Lee JY1, Kim JH2, Kang DH1, Chung DY1, Lee DH1, Do Jung H3, Kwon JK4, Cho KS5.


We investigated whether stone heterogeneity index (SHI), which a proxy of such variations, was defined as the standard deviation of a Hounsfield unit (HU) on non-contrast computed tomography (NCCT), can be a novel predictor for shock-wave lithotripsy (SWL) outcomes in patients with ureteral stones. Medical records were obtained from the consecutive database of 1,519 patients who underwent the first session of SWL for urinary stones between 2005 and 2013. Ultimately, 604 patients with radiopaque ureteral stones were eligible for this study. Stone related variables including stone size, mean stone density (MSD), skin-to-stone distance, and SHI were obtained on NCCT. Patients were classified into the low and high SHI groups using mean SHI and compared. One-session success rate in the high SHI group was better than in the low SHI group (74.3% vs. 63.9%, P = 0.008). Multivariate logistic regression analyses revealed that smaller stone size (OR 0.889, 95% CI: 0.841-0.937, P < 0.001), lower MSD (OR 0.995, 95% CI: 0.994-0.996, P < 0.001), and higher SHI (OR 1.011, 95% CI: 1.008-1.014, P < 0.001) were independent predictors of one-session success. The radiologic heterogeneity of urinary stones or SHI was an independent predictor for SWL success in patients with ureteral calculi and a useful clinical parameter for stone fragility.

Lasers Med Sci. 2016 Apr 7. [Epub ahead of print]

Comparison of the clinical efficacy and safety of retroperitoneal laparoscopic ureterolithotomy and ureteroscopic holmium laser lithotripsy in the treatment of obstructive upper ureteral calculi with concurrent urinary tract infections

Jiang JT1, Li WG1, Zhu YP1, Sun WL2, Zhao W1, Ruan Y1, Zhong C1, Wood K3, Wei HB4, Xia SJ1, Sun XW5.


The aim of this study is to compare the clinical efficacy and safety of retroperitoneal laparoscopic ureterolithotomy (RPLU) and ureteroscopic holmium laser lithotripsy (UHLL) as two minimally invasive procedures in managing obstructive upper ureteral calculi with concurrent urinary tract infections (UTI). The retrospective study included 189 patients who underwent unilateral obstructive upper ureteral stones with concurrent UTI from January 2007 to November 2014 at our institution. Patients received RPLU (81 cases) or UHLL (108 cases). All patients received preoperative anti-infection treatment (indwelling ureteral stent and/or preoperative antibiotics). Collected data, including sex, age, stone size, success rate, operation duration, post-operation hospitalization time, and post-operation complications, were compared. All patients were followed up for more than 6 months after surgeries, and no ureterostenosis occurred. The study included 189 patients, 41 (21.7 %) females and 148 (78.3 %) males with a medium age of 52 years (range 22-81 years). All surgeries were successfully performed without conversion to open surgery. Stone size in the RPLU group was larger than that of the UHLL group (16.1 ± 1.4 vs. 10.4 ± 1.6 mm, P = 0.012). Operative duration (P = 0.009) and hospitalization time (P < 0.001) in the UHLL group were significantly shorter than those in the RPLU group, whereas stone clearance rate was significantly higher in the RPLU group (100 vs. 88.9 %, P = 0.002). Of note, postoperative fever was more common in patients treated with UHLL (15 cases) versus RPLU (4 cases) (13.9 vs. 4.9 %, P = 0.043). Moreover, in the UHLL group, three patients without a preoperative indwelling ureteral stent were complicated with sepsis, which was not seen in RPLU group. In our study, the safety and stone clearance rate of RPLU are better than those of UHLL in the treatment of unilateral upper ureteric calculi with concurrent UTI. Preoperative antibiotics and indwelling ureteral stent may reduce the risk of postoperative infections.