What predicts spontaneous passage of ≤1 cm ureteral stones in children?

PURPOSE: The aim of this study is to determine what factors predict spontaneous passage of ≤1 cm ureteral stones in children. METHODS: Files of the patients diagnosed with a single ureteral stone on a given side between 2008 and 2017 were retrospectively reviewed. Patients with congenital obstructive uropathy, neurogenic bladder, vesicoureteral reflux and those with a stone diameter of >1 cm were excluded. Detection of ureteral stones was done using ultrasonography (US) primarily, and computed tomography when US findings were inconclusive. Patients were treated either conservatively or surgically. Conservative treatment included adequate hydration and pain management whereas surgical treatment included ureteroscopic intervention. Apart from those who required urgent intervention, patients were referred for surgical treatment after 2-4 weeks of follow-up with no spontaneous passage. Factors analyzed for association of spontaneous passage included age, gender, type of hematuria, stone localization, laterality, presence of concomitant kidney stone, degree of hydronephrosis, stone size and stone composition. RESULTS: A total of 70 patients (38 males, 32 females); median age 4.7 years had a ≤ 1 cm ureteral stone (median diameter 7 mm). US was able to diagnose the ureteric stone in 47 patients while computed tomography was required in 23 patients. Spontaneous passage was observed in 40 patients (57.1%). Median time for stone passage was 8 days (3-34 days). Stone size and presence of hematuria (macroscopic and microscopic combined) were factors associated with spontaneous passage and 6.7 mm was found to be the cut-off (AUC = 0.953; 95% CI 0.905-1.000; sensitivity 96.7%, specificity 82.5%, p < 0.001). Moreover, age, degree of hydronephrosis or stone location were not associated with spontaneous passage. CONCLUSION: Patients with a ureteric stone size <6.7 mm can safely be followed conservatively, with a spontaneous passage rate of 82.5%. Type of Study Case series with no comparison group. Level of Evidence IV.

The Role of Antegrade Irrigation via Percutaneous Nephrostomy on Surgical Outcomes in Semirigid Ureteroscopy among Patients with Upper Ureteral Stones.

OBJECTIVE: We aimed to investigate the role of antegrade irrigation via percutaneous nephrostomy on surgical outcomes in retrograde ureteroscopy in patients with upper ureter stones. MATERIALS AND METHODS: In this retrospective study, we analyzed 134 patients who underwent retrograde semirigid ureteroscopy for upper ureter stones between August 2012 and December 2017. Patients were divided into two groups: retrograde irrigation group (conventional URS) and antegrade irrigation group (using percutaneous nephrostomy). Operation time, postoperative hospital stay, complications, and stone-free rate were measured for each patient after ureteroscopy. RESULTS: The mean age in the retrograde irrigation and antegrade irrigation groups was 53.3 and 60.7 years, respectively (p=0.007). The operation time was 60.8 min vs. 43.0 min (p=0.002), and stone-free rate was 82.0 % vs. 95.5 % (p=0.033). Stone size, laterality, the proportion of male patients, and urinary tract infection prevalence were comparable between the groups. In the subgroup analysis of stone size >10 mm, the antegrade irrigation group had a shorter operation time and a higher stone-free rate. For stone size of 5-10 mm, operation time in the antegrade irrigation group was shorter and the stone-free rate between the two groups was comparable. CONCLUSION: Antegrade irrigation via percutaneous nephrostomy during ureteroscopy has a higher stone-free rate with a shorter operation time without an increased urinary tract infection risk. Therefore, if percutaneous nephrostomy is necessary before ureteroscopy, antegrade irrigation of external fluid via percutaneous nephrostomy is strongly recommended.

Ultrasonography Can Replace CT Scans as the Initial Imaging Examination of Ureteral Calculi.

OBJECTIVE: To study the feasibility of ultrasonography (US) as a replacement for CT during the diagnosis of ureteral calculi (UC). MATERIALS AND METHODS: Clinical and imaging data of patients with UC between January 2013 and December 2017 were retrospectively analyzed. According to the imaging method, patients were divided into 3 groups: Group A, CT alone; Group B, CT and US, Group C, US alone. Age, location, and the size of stones were compared among the groups. According to the maximum diameter (MD) measured by using CT in Group B, patients were subdivided into 3 groups (subgroup 1-3): MD <0.5 cm, 0.5 cm ≤ MD ≤1.0 cm, and MD >1.0 cm. The MD measured by US and CT were compared in the subgroups. RESULTS: A total of 1,289 patients with UC were admitted. The use of CT correlated with age (p = 0.000) and stone location (p = 0.004). The sensitivity and specificity of US were 71.3 and 100%. Positive US results correlated with stone size (p = 0.008), but not location (p = 0.861). The mean MDs of the calculi measured by US and CT: in subgroup 1:  0.80 ± 0.31 and 0.35 ± 0.05 cm (p = 0.000); in subgroup 2: 0.94 ± 0.32 and 0.72 ± 0.16 cm (p = 0.000); in subgroup 3: 1.75 ± 0.68 and 1.59 ± 0.52 cm (p = 0.094). CONCLUSIONS: US confirmed that UC do not require confirmatory CT. US can replace CT as the initial imaging examination of UC.

How Effective Is Retrograde Semirigid and Flexible Ureteroscopic Lithotripsy for the Treatment of Large Ureteral Stones Equal of or Greater than 15 mm? Results from a Single Center.

PURPOSE: To present the results and complications of retrograde ureteroscopic lithotripsy for treatment of large ureteral stones. METHODS: Nineteen patients were treated for ureteral stones ≥15 mm detected in CT or plain KUB film. Endoscopy was performed with either a semirigid or flexible ureteroscope. Stone fragmentation was performed using a 30 W Holmium laser. RESULTS: The mean stone size was 20.7 mm (range 15-30). The mean duration of the operation was 82 min (45-140). Measures to prevent retropulsion of fragments into the kidney were not routinely applied. A subsequent RIRS during the same session was necessary in 2 cases. After a single procedure a stone free state was achieved in 15 cases (78.9%), while 4 others required a second session (ESWL or second ureterolithotripsy, 2 cases each). In only 1 patient, the stone-free state was not achieved after a 1.2 procedure per patient (overall success rate 94.7%). The mean duration of hospitalization was 1.9 days (range 1-5). Three patients experienced postoperative pyelonephritis and 2 others prolonged hematuria. CONCLUSION: Endoscopic lithotripsy is safe and effective in treating large ureteral stones. After a single endoscopic procedure, approximately 4 out of 5 patients are expected to become stone free. This rate increases to 95% with a second session of lithotripsy.

Beyond medical expulsive therapy: evolution to supported stone passage for ureteric stones.

OBJECTIVE: To evaluate the impact of removing tamsulosin from standardized ureteric stone clinical protocols on rate of stone surgery. PARTICIPANTS AND METHODS: We conducted a single-centre, comparison of all patients with unilateral, <1 cm ureteric stones presenting to a stone clinic after discharge from the emergency department during consecutive years. In the initial year, patients were initially offered medical expulsive therapy (MET) with tamsulosin. In the subsequent year, the protocol was modified to focus on symptom control without tamsulosin; this was termed 'supported stone passage' (SSP). The primary outcome was rate of stone surgery within 90 days of the initial clinic encounter. RESULTS: Among 723 patients (360 MET, 363 SSP), the rate of attempted stone passage increased from 65% to 74%, between the initial and the subsequent year (P < 0.016). Tamsulosin prescription in patients to attempting stone passage decreased from 84% to 13% (P < 0.001). In patients attempting stone passage, the rate of stone surgery was 26% in the METand 19% in the SSP group (P = 0.066). The overall surgery rate decreased from 51% in the MET group to 40% in the SSP group (P = 0.003). Multivariable analysis, controlling for age, sex and stone burden, did not demonstrate a difference in either rate of attempting to pass stones or in rate of failure of passage according to care protocol. We were unable to demonstrate an independent effect of tamsulosin on failure of passage. Overall, surgical intervention was less likely in the SSP phase than in the MET phase, with an odds ratio of 0.64 (confidence interval) 0.44-0.91; P = 0.013). CONCLUSIONS: Removing tamsulosin from clinical protocols did not impair stone passage in patients attempting to pass stones.

A study on the clinical application of a patented perfusion and suctioning platform and ureteral access sheath in the treatment of large ureteral stones below L4 level.

PURPOSE: The purpose of the study was to evaluate the efficacy and safety of a patented perfusion and suctioning platform and ureteral access sheath in the treatment of large ureteral stones (≥ 1.5 cm) below L4 level. METHODS: We recruited 122 patients with large ureteral stones below L4 level at our hospital from December 2014 to June 2017. The patients were randomly divided into the study and control groups. Multiple operative and perioperative parameters were compared between the two groups. RESULTS: The study group had shorter operation time, less cases of postoperative fever, lower serum levels of PCT, IL-6 and BET within 24 h after surgery, as well as less number of cases receiving secondary surgery than the control group. Moreover, the former had a significantly higher stone clearance rate than the latter (P < 0.05; t-test or χ2 test). CONCLUSIONS: The patented perfusion and suctioning platform and ureteral access sheath are safe and effective in treating large ureteral stones (≥ 1.5 cm) below L4 level.

Can Ureteral Jet Flow Measurement Predict Spontaneous Passage of Distal Ureteral Stones?

OBJECTIVES: The study aimed to investigate the relationship between the spontaneous passage of distal ureteral stones and ureteral jet flow measurement. METHODS: The study included 74 patients with acute renal colic between June 2015 and June 2016, and distal ureteral stones of 10 mm or less in a non-contrast CT were comprised in a prospective study. The ureteral jet was measured by Doppler ultrasonography. At the fourth week follow-up, kidney-ureter-bladder radiography was taken and the patients who no longer had a stone were considered to have spontaneously passed it. RESULTS: The average stone size of the patients was 5.6 ± 2.0 mm. After 4 weeks of follow-up, 55 patients (74.3%) had passed the stone spontaneously whereas 19 (25.6%) had not. The patients in the former group were found to have a higher peak flow velocity of ureteral jet on the stone side than those in the latter group. In regression analysis ureteral jet on the stone side was independently associated with spontaneous passage (p = 0.027). For the spontaneous passage, a ureteral jet flow peak velocity above 15.25 cm/s had an 85.4% sensitivity and 63.1% specificity. CONCLUSIONS: Measurement of the ureteral jet flow peak velocity can be beneficial in predicting the potential spontaneous passage of distal ureteral stones.

Effect of Tamsulosin on Passage of Symptomatic Ureteral Stones: A Randomized Clinical Trial.

Importance: Urinary stone disease is a common presentation in the emergency department, and α-adrenergic receptor blockers, such as tamsulosin, are commonly used to facilitate stone passage. Objective: To determine if tamsulosin promotes the passage of urinary stones within 28 days among emergency department patients. Design, Setting, and Participants: We conducted a double-blind, placebo-controlled clinical trial from 2008 to 2009 (first phase) and then from 2012 to 2016 (second phase). Participants were followed for 90 days. The first phase was conducted at a single US emergency department; the second phase was conducted at 6 US emergency departments. Adult patients were eligible to participate if they presented with a symptomatic urinary stone in the ureter less than 9 mm in diameter, as demonstrated on computed tomography. Interventions: Participants were randomized to treatment with either tamsulosin, 0.4 mg, or matching placebo daily for 28 days. Main Outcomes and Measures: The primary outcome was stone passage based on visualization or capture by the study participant by day 28. Secondary outcomes included crossover to open-label tamsulosin, time to stone passage, return to work, use of analgesic medication, hospitalization, surgical intervention, and repeated emergency department visit for urinary stones. Results: The mean age of 512 participants randomized to tamsulosin or placebo was 40.6 years (range, 18-74 years), 139 (27.1%) were female, and 110 (22.8%) were nonwhite. The mean (SD) diameter of the urinary stones was 3.8 (1.4) mm. Four hundred ninety-seven patients were evaluated for the primary outcome. Stone passage rates were 50% in the tamsulosin group and 47% in the placebo group (relative risk, 1.05; 95.8% CI, 0.87-1.27; P = .60), a nonsignificant difference. None of the secondary outcomes were significantly different. All analyses were performed according to the intention-to-treat principle, although patients lost to follow-up before stone passage were excluded from the analysis of final outcome. Conclusions and Relevance: Tamsulosin did not significantly increase the stone passage rate compared with placebo. Our findings do not support the use of tamsulosin for symptomatic urinary stones smaller than 9 mm. Guidelines for medical expulsive therapy for urinary stones may need to be revised. Trial Registration: ClinicalTrials.gov Identifier: NCT00382265.

[Subcapsular renal hematomas after ureteroscopic lithotripsy].

INTRODUCTION: Renal hematomas (RH) are a rare complication of retrograde endoscopic lithotripsy (REL). This study aimed to investigate the incidence and causes of RH after REL in patients with ureteral stones of different locations. MATERIALS AND METHODS: From 2001 to 2016, 1214 REL were performed at the Urology Clinic of the Mechnikov NWSMU. The analyzes of patients who had RH after REL included the following parameters: age, gender, history of upper urinary tract (UUT) surgery and concomitant diseases (diabetes mellitus, hypertension), the baseline kidney function, the stone characteristics and the degree of hydronephrosis observed in the postoperative period, results of laboratory tests, ultrasound and spiral computed tomography (SCT) of the kidneys. RESULTS: Renal hematomas were diagnosed in 4 (0.3%) of 1214 patients aged 36 to 50 years who had obstructive upper ureteral stones measuring from 0.8 to 1.2 cm in diameter. Three of them previously had UUT surgery: two had REL, and one female patient with a solitary left kidney twice underwent percutaneous nephro- and ureterolithotripsy. All four patients had a triad of symptoms: side flank pain, fever, and anemia. In three patients hematomas were diagnosed on day 2-3 and in one it was found two weeks after the surgery. Two of them were managed with conservative therapy, including bed rest and antibiotics. One patient underwent an ultrasound guided puncture and drainage of the hematoma. In the patient with a solitary kidney, laparoscopic drainage of RH was performed due to growing hematoma and aggravating renal insufficiency. Two patients received blood transfusions. Follow-up kidney SCT showed complete resolution of hematomas in all patients. CONCLUSION: Renal hematomas are a rare but serious complication of REL. The presence of side flank pain, fever and anemia may be indicative of REL and requires a kidney ultrasound. Management of RH should be patient specific, depending on the severity of the patients condition.

On medical treatment for ureteral stone expulsion.

There is evidence that α-adrenoceptor (α-AR) antagonists facilitate the passage of ureteric stones, but the mechanism behind this effect has not been established. If one accepts that it is the friction between a ureteral stone and the mucosa that hampers the passage of the stone, and that the passage traumatizes the mucosa, the aim of treatment must be to reduce this friction. Elevated pressure above an obstructing stone results in an increase in tension in the wall of the upper urinary tract, including the tension at stone level, which causes an increase in friction and ureteric colic. Reducing pressure, by low but adequate fluid intake, non-steroidal anti-inflammatory drugs (NSAIDs), or α-AR antagonists that reduce the friction and give pain relief, seems to be rational. When the stone is pressed downwards by a high pressure the mucosa forms a bar ahead of the stone. These factors reduce the ureteral lumen and hamper the passage of both urine and the stone. The swelling can be reduced by NSAIDs. Filling of the ureter ahead of the stone reduces the friction between the stone and the ureteral mucosa. Evacuation of the urine ahead of the stone by effective peristaltic activity increases this friction. α-AR antagonists that reduce peristalsis may therefore be used to reduce the friction and consequently allow the stones to pass more often and earlier. For very early stone expulsion, a combination of NSAIDs and α-AR antagonists may be useful. There is no evidence that spasm influences the passage of ureteral stones.

Risks of flexible ureterorenoscopy: pathophysiology and prevention.

Currently, indications for flexible ureterorenoscopy (fURS) are expanding, mainly due to technological advancements. Although data from clinical series definitely presents fURS as a safe procedure, serious complications including sepsis and ureteral lesions do occur. These complications seem to be a result of the unique elements of fURS, ureteral access and irrigation, pushing normal upper urinary tract physiology into pathophysiological processes, including intrarenal/pyelo-veneous backflow and ureteral contractions, potentially resulting in septic, haemorrhagic and ureteral lesional complications. Knowledge on normal upper urinary tract physiology are crucial for understanding how these harmful effects of fURS may be avoided or minimized. The pathophysiology of intrarenal pressure increases and ureteral access will be discussed as a basis for understanding preventive measures. Role of antibiotics, ureteral access sheaths, safty guidewires, pain medication, prestenting and pharmacologic modulation of pyeloureteral dynamics are reviewed from a pathophysiological perspective.

Ultrasound Diagnosis of Clinically Unsuspected Ureteral Stone Presenting as Acute Scrotum: Case Series.

Ureteral colic is not generally included in the differential diagnoses of acute scrotal pain, although ureteral pathology is a recognized cause of pain referred to the scrotum. We report 3 patients presenting with acute scrotal pain who had normal scrotal color Doppler ultrasound scans; subsequent ultrasound of the ipsilateral kidney revealed hydronephrosis, which ultimately led to the clinically unsuspected diagnosis of ureteral colic. We conclude that ureteral colic should be included in the differential diagnosis of acute scrotal pain, and we further suggest that a survey ultrasound of the kidney on the side of the pain should be performed in patients presenting with acute scrotal pain and a normal color Doppler ultrasound examination of the scrotum.

Ureterolithiasis: Management in an environment with limited facilities.

BACKGROUND: In the past 2-3 decades, there has been a dramatic development in the techniques of stone removal. This study highlights the management of symptomatic ureteral stones in an environment without such facilities. MATERIALS AND METHODS: Sixty-nine patients, comprising 53 (76.8%) males and 16 (23.2%) females, diagnosed of symptomatic ureteric calculi within the study period in two tertiary health institutions were included in the study. Thorough history taking and physical examinations were performed. Extensive laboratory investigations using blood and urine specimens were carried out. Imaging studies, ultrasonography, intravenous urography, and computerized tomographic scan were used to locate the position and size of the calculi. RESULTS: Forty-six (66.7%) patients presented with excruciating flank ureteric colic radiating to the groin in 16 (23.2%) patients and hematuria in 62 (89.9%) patients. Bilateral ureteric calculi occurred in 3 (4.3%) patients. Eleven (15%) stones passed spontaneously. 33 (47.8%) patients had uneventful open surgery. The stones were mixed in nature. CONCLUSION: Management of ureteric stones in our environment is affected by delay in presentation, low level of awareness of urinary stone disease, lack of modern endourological equipment, and paucity of urological surgeons. Finally, medical treatment should be explored for stones below 10 mm in size.

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.

Renal colic, where is it headed? An observational study.

AIM: In the last thirty years, the treatment for renal and ureteral calculi has undergone profound variations. The objective of this study has been to evaluate the existence of parameters which can affect the spontaneous expulsion of a symptomatic ureteral stone in a reasonably brief period of time and to identify whether certain parameters such as sex, age, the location and dimension of the stone, the presence of dilation in the urinary tract together with the administered therapy, can be used for a correct clinical management of the patient. METHODS: In a period of 9 months, 486 cases of renal colic were registered at emergency department. RESULTS: The cases of renal colic due to ureteral calculus were 188 (38.7%). The patients' charts, complete of all data and therefore, valid for this research, resulted to be 120 (64%). In the presence of a symptomatic ureteral stone, the correct approach must first of all, focalize on the dimension of the calculus itself; less importance instead, is given to the location, as reported in other studies, the presence of hydroureteronephrosis, sex and the side. CONCLUSION: In the cases when the pain symptoms cannot be solved by means of the administration of analgesics, it is then reasonable to take into consideration an immediate endourological treatment. If the pain symptoms are promptly solved, an attentive wait of 4 weeks should be considered reasonable in order to allow spontaneous expulsion of the calculus.

Irreversible Renal Function Impairment Due to Silent Ureteral Stones.

OBJECTIVE: To evaluate if renal function loss and hydronephrosis due to a silent ureteral stone might be reversed. MATERIALS AND METHODS: We prospectively selected patients with silent ureteral stones between January 2006 and January 2014. 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, 3 and 12 months postoperatively. Renal function was accessed in the same intervals with serum creatinine (SCr), glomerular filtration rate (GFR), and (99m)Tc-dimercaptosuccinic acid. Patients without complete pre- and postoperative evaluation were excluded. Primary end point was midterm 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. Analysis of variance with repeated measures and marginal homogeneity test were used to evaluate renal function and hydronephrosis progression. RESULTS: Twenty-six patients met our inclusion criteria. Mean preoperative SCr and GFR were 1.24 mg/dL and 72.5 mL/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 = .89), GFR (P = .48), and renal function at scintigraphy (P = .19) during follow-up. Hydronephrosis significantly improved from preoperatively to 3 months postoperatively (P < .0001), but not from 3 to 12 months (P = .065). CONCLUSION: Patients with silent ureteral stones present with significant impairment of ipsilateral renal function and hydronephrosis at diagnosis. On midterm follow-up evaluation, renal function of the affected unit remains stable whereas hydronephrosis improves after treatment.

The Difficult Ureter: Clinical and Radiographic Characteristics Associated With Upper Urinary Tract Access at the Time of Ureteroscopic Stone Treatment.

OBJECTIVE: To evaluate the association between clinicoradiographic features and need for prestenting (PS) because of inability of the ureter to accommodate the ureteroscope, or ureteral access sheath, at the time of stone treatment. MATERIALS AND METHODS: From 2009 to 2013, 120 consecutive nonstented patients underwent ureteroscopic stone treatment with preoperative computerized tomography urogram. Acute stone events with obstruction or infection were excluded. Preoperative radiographic imaging underwent radiologist review. Clinicoradiographic features were characterized, and multivariable logistic regression models were used to identify covariates independently associated with need for PS. RESULTS: Of the 154 renal units treated, 25 (16%) required PS for failed primary access. PS ureters were less likely to have a history of prior ipsilateral ureteral stent (4% vs 31%) or surgery (8% vs 36%; P <.05). Radiographically, PS ureters had a narrower ureteropelvic junction (4 mm vs 5 mm) and were more likely to have <50% ureteral opacification on computerized tomography urogram (32% vs 9%; P <.05). On multivariable analysis, prior ipsilateral ureteral stent (odds ratio [OR] = 0.11) and stone surgery (OR = 0.15) reduced the need for PS; meanwhile, <50% ureteral opacification (OR = 4.41) was independently associated with an increased risk of access failure. CONCLUSION: We report a 16% incidence of access failure requiring PS at time of ureteroscopy. Clinically, there was an 89% and 85% risk reduction in the need for PS with prior history of ipsilateral ureteral stent or surgery. Radiographically, there was a 4.4-fold increased risk of PS with <50% ureteral opacification. Accordingly, our findings may assist in counseling and operative management of the difficult ureter.