Ureteropyeloscopic treatment of ureteral and intrarenal calculi

Comparison of flexible vacuum-assisted ureteral access sheath versus conventional sheath combined with single-use flexible ureteroscope in the treatment of renal calculi

To evaluate the safety and efficacy of the flexible vacuum-assisted ureteral access sheath combined with the single-use flexible ureteroscopy in the treatment of renal calculi. We prospectively analyzed the patients treated with single-use flexible ureteroscopy from January 2023 to December 2023, among which 113 cases were treated with flexible vacuum-assisted ureteral access sheath (FV-UAS group) and 113 cases were treated with conventional sheath (conventional sheath group). Patient data ofthe two groups were collected and recorded before and after operation. No significant differences were observed between the two groups regarding demographics and pre-operative clinical characteristics. The duration of the operation was significantly longer in the FV-UAS group (79.5 ± 6.8 min) compared to the conventional UAS group (65.2 ± 7.3 min). However, the stone free rate (SFR) at one day and one month post-operation in the FV-UAS group was 85.6% and 98.2%, respectively, significantly higher than that in the conventional UAS group (72.6%, 90.3%). Complications such as infection and urosepsis were more common in conventional UAS group. Notably, hospitalization costs were lower in the FV-UAS group. Flexible vacuum-assisted ureteral access sheath combined with flexible single-use ureteroscope is a feasible and effective method for treating renal calculi. It offers higher SFR and lower rate of infectious complications.

Effects of the Surgical Ligation of the Ureter in Different Locations on the Kidney over Time in the Rat Model

Purpose

To evaluate the effects of the surgical ligation of the ureter in different locations on the kidney over time in the rat model.

Methods

A total of 155 rats were enrolled and randomly divided into the case (n = 150) and control (n = 5) groups. The case group included three separate groups (fifty rats in each group) that underwent surgical ureteral ligation at the proximal, middle, and distal ureter. The laboratory tests, and tumor necrosis factor α (TNF-α), were measured in groups. The pathological evaluation for glomerular changes, tubular dilation, interstitial fibrosis, and interstitial infiltration of the inflammatory cells following the obstruction was performed (severity of tubular atrophy categorized too mild (+), moderate (++), and severe (+++)). To compare the continuous variables between the groups and between the measurement times, the analysis of variance (ANOVA) was used.

Results

Our results revealed that the creatinine four weeks after the obstruction was significantly higher in the proximal group obstruction (p value: 0.046). The three groups had no significant differences regarding urine creatinine, serum sodium, and serum TNF (p value: 0.261). Obstruction did not change the glomerular morphology in three intervention groups after six weeks. The commencing of severe tubular atrophy in proximal, middle, and distal ureteral obstruction was at weeks three, four, and six, respectively.

Conclusion

The location of ureteral obstruction is also crucial in deciding to intervene to relieve the complete ureteral obstruction. Severe tubular damage occurs in weeks three, four, and six in proximal, middle, and distal ureteral obstruction, respectively.

Safety and efficacy of retrograde intrarenal surgery in primary and residual renal calculi in children

BACKGROUND

Minimal invasive approach is the current standard of care in the management of pediatric renal calculi. Current guidelines are clear with extra corporal shock wave lithotripsy (ESWL) and percutaneous nephrolithotomy (PCNL) for stone size less than and greater than 20 mm respectively. Although retrograde intrarenal surgery (RIRS) is well established in adults but literature on its role, safety and efficacy in children is sparsely available.

OBJECTIVE

To share our experience of RIRS and its outcome in a pediatric population in both primary and residual calculi of size less than 20 mm.

MATERIALS AND METHODS

We retrospectively analysed data of children who underwent RIRS for either primary or residual renal calculi from January 2017 to January 2021. Children less than 5 years underwent passive ureteric dilatation with stenting preoperatively. A7.5 Fr flexible ureteroscope with an access sheath was used in all cases while performing RIRS. All the patients had a stent left in situ at the end of the procedure. Data including stone burden, number of sittings, operative time, stone-free rate (SFR) and grade of post procedural complications were analysed with appropriate statistical methods.

RESULTS

A total of 20 patients were included in this study. The median age at presentation was 9 years ranging from 9 months to 18 years. Eight patients (40%) presented with primary renal calculi and underwent RIRS directly while the rest of the 12 (60%) had residual calculi following other procedures like SWL, PCNL before undergoing RIRS. Seven patients (35%) had congenital renal anomalies. The mean stone size and operating time (OR) was 12.6 ± 3.2 mm 84.5 ± 7.2 min respectively. The post-procedural complications were seen in 4 (20%) patients in the form of Grade-1 modified Clavein classification in 3 and Grade 2 in 1 patient. The 100% stone-free rate was achieved in 80% of the cases after first attempt.

DISCUSSION

In the present series, RIRS was effective in both the types of stones (primary and residual) less than 20 mm in size, showing 100% stone free rate with maximum of two attempts. Choosing age based optimised passive ureteric dilation led to injury free access for RIRS. Overall complications remained with in low grades and are comparable to current literature. Limitations of the study include small cohort, retrospective study and the need of three anaesthesia procedures in children under 5 years of age.

CONCLUSION

RIRS is safe and effective in children with a renal stone(s) less than 20 mm and it has a high success rate in term of achieving stone free status in both primary and residual calculi.

Bilateral same-session flexible ureteroscopy for renal stones: a feasible method

A staged ureteroscopic procedure is generally preferred to treat bilateral renal stones. In this study, we evaluated the feasibility of bilateral same-session flexible ureteroscopy (BS-fURS) in renal stones. A total of 81 patients underwent bilateral BS-fURS between March 2014 and March 2021 for bilateral renal stones. The mean stone burden per patient was 17±4 (range 7-27 mm). The average stone density was 1240 HU (970 to 1510). We used 4 types of ureteroscopes: Olympus URF-V2 (34 cases), Storz Flex X2 (30 cases), single-use PUSEN PU 3022 (12 cases), and single-use PUSEN - PU 3033A (5 cases). We specifically set our Holmium laser for dusting, pop-corning, and fragmenting. We found 31 calcium oxalate monohydrate cases, 11 calcium oxalate dehydrate cases, 17 uric acid cases, and 22 magnesium ammonium phosphate cases. The mean operating time was 77 min. (range 52 to 85) for both renal units. The SFRs were evaluated between 1 and 3 months with computed tomography (fragments >3 mm were defined as residual). Double J stenting (6Fr.) was applied bilaterally in 8 cases (9.87%) and unilateral in 34 cases (41.97%). The overall SFRs after 1 and 2 procedures were 81.48% (66/81 cases) and 92.59% (75/81 cases), respectively. Postoperative complications after an overall 96 procedures were Clavien I-II (18.75%) and Clavien III (3.12%). Urinary tract infections were observed in 13 cases (16.04%) without any case of urosepsis. Our experience suggested some BS-fURS advantages as a single anesthetic session and potentially reduced cost associated with treatment. BS-fURS seem feasible, especially for medium-sized bilateral renal stones in high-volume centers.

Superselective renal arterial embolization in treatment for severe renal hemorrhage after flexible ureterorenoscopy and laser lithotripsy (FURSL)

OBJECTIVE

Life-threatening renal hemorrhage after flexible ureterorenoscopy and laser lithotripsy (FURSL) is a rare complication. We aim to review our unit's experience with super-selective renal artery embolization as therapeutic options for such patients.

METHODS

From January 2015 to November 2021, total 1125 patients underwent the FURSL procedures in our unit. Patients with life-threatening renal hemorrhage were reviewed and the information of peri-operative, operative and post-operative were recorded.

RESULTS

Of the 1125 patients who underwent FURSL procedure, two patients with life-threatening renal hemorrhage were diagnosis; the age is 67 and 42 years old, respectively. Preoperative imaging examination showed that two patients had upper ureteral stone and renal stone ranging in size from 1.2 to 3.0 cm. Female patient placed the D-J stent for two weeks before FURSL. After the operation, both patients had the massive gross hematuria, significant drop of hemoglobin (Hgb), blood pressure lowering and needed to transfusion. CT scan showed that the male patient had an intrarenal hematoma. All these two were treated by super-selective renal artery embolization and had a successful outcome.

CONCLUSION

Life-threatening renal hemorrhage after FURSL is a rare and severe complication. Super-selective renal artery embolization is a safe and effective method for the treatment of patients with severe renal hemorrhage, preserving healthy renal parenchyma and renal function.

The clinical outcomes of flexible ureteroscopy and laser lithotripsy (FURSL) for treatment of the upper urinary tract calculi

PURPOSE

To evaluate efficacy and safety of flexible ureteroscopy and laser lithotripsy (FURSL) for treatment of the upper urinary tract calculi.

METHODS

We retrospectively analyzed 784 patients who underwent FURSL between January 2015 and October 2020 in our unit. All patients were preoperatively evaluated with urine analysis, serum biochemistry, urinary ultrasonography, non-contrast computed tomography and intravenous urography. The procedure was considered as successful in patients with complete stone disappearance or fragments < 4 mm on B ultrasound or computed tomography. The operative parameters, postoperative outcomes and complications were recorded and analyzed respectively.

RESULTS

The average operative time and postoperative hospital stay were 46.9±15.8 min and 1.2±1.1 days, respectively, among 784 patients. In addition, 746 patients were followed up and 38 patients were lost. In these patients, 700 (93.8%) cases met the stone removal criteria and 46 cases (6.2%) did not meet the stone removal criteria who need further treatment. The stone free rate (SFR) is 92.5%after 1-3 months and SFR of middle and upper calyceal calculi was higher than that of lower calyceal calculi significantly. The most common complications were fever (58/784, 7.4%), gross hematuria (540/784, 68.9%) and lpsilateral low back pain (47/784, 6.0%). The incidence rate of serious complication was 1.28%(10/784), including 5 cases of septic shock and 5 cases of subcapsular hematoma, which were cured after active treatment.

CONCLUSION

FURSL is a reliable treatment for small and medium calculi patients of upper urinary tract. The curative effect of stone removal is clear. The complications are few and the safety is high. However, there are certain limitations to the efficacy in treating larger stone and lower calyceal calculi.

Retrograde ureteroscopy in the management of distal ureteric stones: A retrospective analysis of outcome and complications

Background

Urinary stones affect 8%-15% of the world population. In Nigeria, contemporary reports have shown that the incidence of urinary stones is rising. The distal ureter has been described as the most common location of ureteric stones. This study seeks to review our experience in the ureteroscopic management of distal ureteric stones with a view to appraising the stone clearance rate and the complications seen in our patients.

Patients and Methods

This descriptive study reviewed the record of 21 patients, who had semirigid ureteroscopy and pneumatic lithotripsy for distal ureteric stone between October 2015 and September 2018. All patients had computed tomography urography preoperatively to locate the stone. Data on patients' demographics, indication for the surgery, location and size of stone, preoperative double-J (DJ) placement, postoperative DJ stent placement, intraoperative and postoperative complications, and status of stone clearance were retrieved and subjected to statistical analysis.

Results

The mean age of the patients was 37.95 ± 11.09 (range, 21-67) years. The mean stone size was 8.06 ± 2.87 mm with a range of 4.8 mm-15.0 mm. Out of the 21 patients, 20 (95.2%) had the procedure for recurrent ureteric colic and 1 (48%) was for hematuria. Four (19.0%) patients had DJ stent preoperatively, whereas 17 (81.0%) patients did not have. Fourteen (66.7%) patients had intraoperative ureteric dilatation. Postoperative DJ stent was placed in 17 (81.0%) patients, whereas 4 (19.0%) patients did not have. Three (14.3%) patients had mucosal flap, 6 (14.3%) had mucosal abrasion, 2 (9.5%) had bleeding, 1 (4.8%) patient had transient hematuria postoperatively, and 2 (9.5%) patients had urinary tract infection. Nineteen (90.5%) patients had complete clearance in a single surgery. Two (9.5%) patients had symptomatic residual fragments that required repeat ureteroscopy.

Conclusion

Our study has shown that ureteroscopy is a useful and safe technique in the removal of stones in distal ureter.

The role of super-mini percutaneous nephrolithotomy (SMP) in the treatment of symptomatic lower pole renal stones (LPSs) after the failure of shockwave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS)

To assess the safety and efficacy of super-mini percutaneous nephrolithotomy (SMP) in the treatment of symptomatic lower pole renal stones (LPSs) after the failure of shockwave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS), we retrospectively evaluated 44 patients with symptomatic LPSs with previously failed SWL or RIRS and consequently underwent SMP from October 2014 to March 2016. The percutaneous renal access was performed 12-14F with C-arm fluoroscopy or ultrasonographic guidance. Stone disintegration was performed using either Holmium laser or pneumatic lithotripter. Perioperative parameters along with operations were assessed in detail. A total of 44 patients (mean age 49.1 ± 13.7 years) were included in the study. Stone size was 18.4 ± 6.0 mm (range 9-29), operative time was 63.9 ± 32.7 min (range 14-145) and hospital stay was 2.8 ± 1.2 days (range 1-5). The hemoglobin drop was 12.4 ± 8.8 g/L (range 0-31), and no patients required blood transfusion. Complete stone-free status was achieved in 40 (90.9%) patients. Clinically insignificant residual fragments were observed in three (6.8%) patients and only one (2.3%) patient had a 6 mm residual calculus. A total of three minor complications (urinary tract infection, hemorrhage resolved by hemostatics and renal colic requiring analgesics) were observed postoperatively. For symptomatic LPSs after the failure of SWL or RIRS, SMP is a safe and efficient auxiliary option and even might be an alternative to SWL or RIRS, while further considering the stone-free rates and stone-related events.

Miniaturized percutaneous nephrolithotomy versus retrograde intrarenal surgery in the treatment of renal stones with a diameter <15 mm: A 3-year open-label prospective study

Aim

The aim of this study is to compare the outcomes of miniaturized percutaneous nephrolithotomy (mini-perc) and retrograde intrarenal surgery (RIRS) in management of renal stones with a diameter <15 mm.

Materials and Methods

This was an open-label prospective study that included a total of 80 cases underwent mini-perc (n = 40) and RIRS (n = 40) between July 2014 and August 2017. The primary outcome objective was stone-free rate, retreatment rate, complications, hospital stay, operative time, and reduction in hemoglobin level. Data were analyzed using SPSS version 16.0 Software.

Results

Overall, 80 patients were enrolled in this study. The mean age was 40.12 and 38.20 years, and the mean stone size was 1.15 and 1.30 cm in mini-perc and RIRS group, respectively. Majority of the study participants were males. Overall, mini-perc and RIRS had stone clearance rates of 100% and 95.4%, respectively. Two patients required retreatment in RIRS group. The duration of hospital stay and the rate of complication was similar in both the groups. Operative duration was more in RIRS group. Decrease in hemoglobin level was more in mini-perc group.

Conclusions

Results demonstrated that both modalities were associated with high stone clearance rates with minimal complications. RIRS was associated with less reduction in hemoglobin and could be used as standard treatment modality for small renal calculi.

Low dose lignocaine + butorphanol vs. low dose bupivacaine for spinal anaesthesia in day care urological surgeries: a prospective randomized control trial

OBJECTIVE

A local anaesthetic with fast onset, short and reliable duration of anaesthesia may be preferable for day care urological surgeries. Low dose lignocaine is believed to act faster and to have a shorter duration of action than low dose bupivacaine. Use of lignocaine for spinal anesthesia is discouraged now a days because of rare reports of transient neurological symptoms. The purpose of this study was to compare effectiveness and safety of low dose of lignocaine + butorphanol against low dose of bupivacaine for day care urological surgeries.

MATERIAL AND METHODS

A prospective randomized control trial was conducted between December 2012 to November 2015. After taking ethical committe approval and patient consent, total 990 patients were randomized in two groups. Group A received 0.5 mL of 5% lignocaine (25 mg) + 0.3 mL butorphanol (0.3 mg) and group B received 1 mL of 0.5% bupivacaine (5 mg) for spinal anesthesia. Spinal anesthesia was given at the L3-L4 interspace with the patient in the sitting or lateral position. The criteria for evaluation were time till onset of sensory and motor block, duration of sensory and motor block, time till ambulation, time till fit for discharge and any complications.

RESULTS

Both the groups were comparable in terms of age, male to female ratio, American Society of Anesthesiologists (ASA) grade and duration surgery. Group A and Group B were statistically different in terms of mean time till onset of sensory block (120±22 sec and 274±36 sec), onset of motor block (228±34 sec and 372±41 sec), duration of sensory block (100±21 min and 230±28 min), duration of motor block (60±15 min and 152±23 min), time till ambulation (138±24 min and 292±48 min), time till fit for discharge (256±35 min and 428±46 min) respectively (<0.0001). Nausea, vomitings, hypotension, bradycarida and pruritis were less in group A compared to group B (<0.01). None of patient in any group had temporary or permanent neurological defecit.

CONCLUSION

Spinal anaesthesia is an effective as well as a safe modality to anaesthetize the patient for day care urological procedures. This study shows lignocaine + butorphanol is preferable over bupivacaine for spinal anesthesia for day care urological procedures. It also favours day care surgery at remote areas with lesser medical facilities. It helps to minimize requirement of medical and paramedical staff, thus further extending scope of day care urological surgeries.

Evaluation of postoperative hydronephrosis following semirigid ureteroscopy: Incidence and predictors

OBJECTIVE

Hydronephrosis developing following ureteroscopy (URS) is an important issue associated with the long-term postoperative renal functions. Studies investigating the role of postoperative imaging revealed conflicting results. In this study, we aimed to determine the incidence and predictors of hydronephrosis following semirigid URS.

MATERIAL AND METHODS

We evaluated the results of 455 patients who underwent U RS a nd postoperative imaging with non-contrast computed tomography (CT). Primary endpoints of the study were to determine the frequency of development of hydronephrosis and factors associated with the development of hydronephrosis. Logistic regression analysis was used to define factors effecting on the development of hydronephrosis.

RESULTS

Postoperative non-contrast CT revealed hydronephrosis in 81 (17.8%) patients. Stone-free status was achieved in 415 (91.2%) patients. Univariate analysis revealed history of ipsilateral URS (p=0.001), duration of operation (p=0.022), presence of multiple stones (p=0.001), and occurrence of a renal colic episode postoperatively (p=0.013) as the parameters associated with increased risk of postoperative hydronephrosis. In the multivariate analysis, history of ipsilateral URS (OR: 2.724, p=0.017) and presence of multiple stones (OR: 2.116, p=0.032) were found to be the independent prognostic markers of developing postoperative hydronephrosis.

CONCLUSION

Ipsilateral hydronephrosis following URS develops in a significant number of patients. In patients with history of ipsilateral hydronephrosis and multiple stones, risk of development of postoperative hydronephrosis is higher, therefore physicians should be keep these parameters in mind in the decision making process of selective imaging postoperatively.

Three-Dimensional Numerical Simulations of Peristaltic Contractions in Obstructed Ureter Flows

Ureteral peristalsis can be considered as a series of waves on the ureteral wall, which transfers the urine along the ureter toward the bladder. The stones that form in the kidney and migrate to the ureter can create a substantial health problem due to the pain caused by interaction of the ureteral walls and stones during the peristaltic motion. Three-dimensional (3D) computational fluid dynamics (CFD) simulations were carried out using the commercial code ansys fluent to solve for the peristaltic movement of the ureter, with and without stones. The effect of stone size was considered through the investigation of varying obstructions of 5%, 15%, and 35% for fixed spherical stone shape. Also, an understanding of the effect of stone shape was obtained through separate CFD calculations of the peristaltic ureter with three different types of stones, a sphere, a cube, and a star, all at a fixed obstruction percentage of 15%. Velocity vectors, mass flow rates, pressure gradients, and wall shear stresses were analyzed along one bolus of urine during peristalsis of the ureteral wall to study the various effects. It was found that the increase in obstruction increased the backflow, pressure gradients, and wall shear stresses proximal to the stone. On the other hand, with regard to the stone shape study, while the cube-shaped stones resulted in the largest backflow, the star-shaped stone showed highest pressure gradient magnitudes. Interestingly, the change in stone shape did not have a significant effect on the wall shear stress at the obstruction level studied here.

Incidence and Predictors for Ipsilateral Hydronephrosis Following Ureteroscopic Lithotripsy

OBJECTIVE

To review our experience in using ureteroscopy (URS) with lithotripsy for renal or ureteral calculi to determine the incidence and predictors of postprocedural ipsilateral hydronephrosis.

PATIENTS AND METHODS

Records of 324 URS cases for renal or ureteral calculi with imaging performed 4-12 weeks postprocedure were reviewed. Ipsilateral hydronephrosis was determined by computed tomography scan or renal ultrasound. Univariate and multivariate analyses determined the factors associated with hydronephrosis.

RESULTS

176 men and 148 women with a median age of 50 years were included. Median stone size was 6 mm and operative duration was 60 minutes; 30% of patients had multiple calculi; and 35% had undergone a prior ipsilateral URS. Overall, 49 of 324 patients (15%) had evidence of hydronephrosis, with 65% of these patients having symptoms and 40% requiring ancillary procedures. On multivariate analysis, increasing stone diameter (odds ratio [OR] 8.9, 95% confidence interval [CI] 1.9-23.8, P = .03), prior ipsilateral URS (OR 7.7, 95% CI 1.8-28.2, P = .006), longer operative duration (OR 6.5, 95% CI 1.8-16.3, P = .02), and renal colic symptoms (OR 48.3, 95% CI 14.7-71.4, P <.001) independently predicted hydronephrosis. Conversely, other factors including stone impaction at procedure, ureteral dilation, use of an access sheath, intraoperative perforation, or use of a stent did not associate with ipsilateral hydronephrosis.

CONCLUSION

In this contemporary cohort study, 15% of patients undergoing URS had evidence of ipsilateral hydronephrosis. Larger stone size, longer OR duration, prior ipsilateral URS, and recurrent colic were associated with an increased likelihood for this observation. Patients and stone cases with such characteristics likely warrant imaging modalities beyond plain radiography.

Comparison between retrograde intrarenal surgery and extracorporeal shock wave lithotripsy in the treatment of lower pole kidney stones up to 15 mm. Prospective, randomized study

INTRODUCTION

Extracorporeal Shock Wave Lithotripsy (ESWL) is currently the recommended treatment for intra-renal calculi smaller than 2 cm. However the low Stone Free Rate (SFR) in lower pole calculi gives rise to new techniques, such us retrograde intrarenal surgery (RIRS), for improve the surgery outcomes.

OBJECTIVE

To compare the efficacy of a treatment with ESWL with RIRS, in terms of SFR after surgery, in patients with kidney stones up to 15 mm in the lower pole.

MATERIAL AND METHODS

A prospective study was carried out in order to assess the results of ESWL and RIRS in patients with lower pole stones less than 15 mm. Among a total of 55 patients, 31 were underwent to ESWL (Group 1) and the remaining 24 to RIRS (Group 2). Clinical data recorded, including general characteristics of each patient, were: calculi size, side, operative time, complications according to Clavien scale, SFR and the presence of residual fragments at 2 months post-treatment assessed by a CT scan. STATA 11 was used to perform the statistical analysis.

RESULTS

There were no differences for general descriptors among groups with the exception of a significantly longer operative time for RIRS. The rates of SFR and residual fragments lesser than 3 mm. were lower in the RIRS group than in ESWL ones. RIRS also showed a lower rate of clinically significant fragments (0% vs 42.3%. P < .05). In the subgroup of patients with stones between 10/15 mm RIRS showed higher SFR (75% vs. 41.2%) and a lower rate of stones>3 mm (0% vs. 58.8%), being statistically significant (P < .05). Clavien III or higher complications were not reported in any of the groups.

CONCLUSIONS

In the treatment of lower pole stone RIRS has the same results than ESWL in terms of SFR. Regarding absence of a clinically significant residual fragment, RIRS was superior to ESWL. A bigger sample size is required in order to confirm this results.

Ureteroscopy and laser lithotripsy: technologic advancements

Ureteroscopic lithotripsy has evolved since the first reported cases employing rigid rod-lens endoscopes and stiff ultrasonic lithotrites. Fiber optics facilitated rigid endoscope miniaturization and the development of a steerable, deflectable flexible ureteroscopes. Over 30 years of technical innovations culminating in digital imagers and powerful, precise laser lithotrites, complimented by progressive endoscopic techniques have produced efficient endoscopic therapies with minimal morbidity and commonly performed in an outpatient setting.

Retrograde intrarenal surgery for the treatment of renal stones in children: factors influencing stone clearance and complications

BACKGROUND

Retrograde intrarenal surgery (RIRS) is a known option for the treatment of upper tract calculi with an excellent success. However, the reports of RIRS in prepubertal children are limited. In this study, we evaluated the factors which affected the success rate and the complications of RIRS at renal stone treatment in childhood.

METHODS

We retrospectively reviewed the records of children under 14 years old who underwent RIRS for renal stone disease between January 2009 and December 2012. Patients' age, gender, body mass index (BMI), stone size, stone location, stone number, intraoperative complications, stone free status, postoperative complications were recorded.

RESULTS

There were 80 ureterorenoscopic procedures performed in 58 renal units of 47 children (23 males and 24 females). The patients' ages ranged from 8 months to 14 years (mean age 4.7 ± 3.4 years). There was a difference in the distribution of symptoms in age groups. UTI was higher in the 1-4 years age group, abdominal pain was seen mostly in children aged 5-14 years. Multiple stones (included staghorn stone) were noted in 60.4% of patients. In 27.6% of patients, ureteral stones were accompanied by renal stones in our series. In the infancy group, cystine and staghorn stones were more frequently seen, mostly bilateral. After a single ureteroscopic procedure for intrarenal stones in children, we achieved stone free status in 50.9% of the ureters (n=26). After the repeated sessions, the stone clearance rate reached to 85.1%.

CONCLUSION

Retrograde intrarenal surgery can be used as a first line therapy to treat renal stones in children. This is especially important if an associated ureteral stone is present that requires treatment; or in patients with cystinuria, which is not favorably treated with ESWL. Complications were seen more frequently in patients with cystine stones. Extravasation was noted more frequently in patients admitted with UTIs. There was a significant relationship between the conversion to open procedures and the age groups, with most procedures occurring in infancy. The parents should be informed about the probability of multiple procedures to achieve stone free status.

Ureteroscopic lithotripsy in Trendelenburg position for proximal ureteral calculi: a prospective, randomized, comparative study

PURPOSE

We conducted a prospective, randomized, comparative study to compare the clinical outcome between the Trendelenburg position ureteroscopic lithotripsy (tURSL) and the conventional position ureteroscopic lithotripsy (cURSL) for the management of single proximal ureteral stone.

METHODS

From January 2012 to September 2013, consecutive patients with single proximal ureteral calculi less than 2 cm and planned for ureteroscopic lithotripsy at our institution were enrolled in this study. The eligible patients were randomized into cURSL group and tURSL group according to sequence of random numbers generated by computer. In tURSL group, patients were turned into a Trendelenburg lithotomy position with head down 30° while the conventional lithotomy position was applied in cURSL group. URSL was performed using a 6/7.5F semi-rigid ureteroscope with holmium laser. When retropulsion occurred, the stones fragments were followed by semi-rigid ureteroscope up to the renal collecting system. The Olympus P5 flexible ureteroscope was used if there was any suspicion of stone migration into lower calices or incomplete stone fragmentation by semi-rigid ureteroscope. Patients' demographics between the two groups, perioperative course, clinical outcome and complication rates were compared. Data were analyzed using Chi-square test, Fisher's exact test or Student's t test. Binary logistic regression analysis was applied to estimate the effects of surgical position and stone size on stone migration.

RESULTS

A total of 355 cases were finally analyzed in this study (176 in cURSL group and 179 in tURSL group). The mean operative time was significantly prolonged in cURSL group than in tURSL group, while the stone-free rate (SFR) at 4 weeks was significantly higher in tURSL group. A statistically significant difference was found in stone migration rate between the two groups (26.7 vs. 43.6 %, P = 0.001). In the stone migration subsetting, less stones fragments were found to migrate into lower calices in tURSL stone migration subgroup (P = 0.000). Also, the flexible ureteroscope utilization as well as the operative time was significantly decreased in tURSL stone migration subgroup (25.5 vs. 72.3 %, P = 0.000), (44.96 ± 11.0 min vs. 59.17 ± 9.2 min, P = 0.000) with higher SFR after retrograde intrarenal surgery (RIRS) (96.2 vs. 74.5 %, P = 0.000).

CONCLUSION

The tURSL was safe and highly efficacious for the management of proximal ureteral calculus, especially in nonobese patient. Even with important stone migration risk, it rendered higher SFR and less operative time compared with cURSL. Moreover, less utilization of flexible ureteroscope and decreased deflection time in tURSL could potentially reduce the medical cost.

Modified Seoul National University Renal Stone Complexity score for retrograde intrarenal surgery

The Seoul National University Renal Stone Complexity (S-ReSC) score is a well-validated tool for the prediction of stone-free rate (SFR) after percutaneous nephrolithotomy. We modified the S-ReSC score system for application to retrograde intrarenal surgery (RIRS) and evaluated this score. A total of 88 patients who underwent RIRS from 2011 to 2013 were included. The modified S-ReSC score was assigned according to the number of sites involved in the renal pelvis (#1), superior and inferior major calyceal groups (#2-3), and anterior and posterior minor calyceal groups of the superior (#4-5), middle (#6-7), and inferior calyx (#8-9). If the stone was in the inferior sites (#3, #8-9), one additional point per site was added to the original score. The SFR was examined according to the modified S-ReSC score. To evaluate the predictive accuracy, the area under the receiver operating characteristic curve (AUC) was used and compared with the Resorlu-Unsal Stone (RUS) score. The SFR was 85.2% and was significantly decreased in the order of low (1-2: 94.2%), medium (2-4: 84.0%), and high (>4: 45.5%) modified ReSC score groups (p < 0.001). AUCs of the modified S-ReSC score (0.806) and score group (0.766) were higher than the AUC of the RUS score (0.692; p = 0.012 and p = 0.040, respectively). The modified S-ReSC score predicts the SFR after RIRS well. Furthermore, its predictive accuracy is higher than that of the RUS score.

Differences in ureteroscopic stone treatment and outcomes for distal, mid-, proximal, or multiple ureteral locations: the Clinical Research Office of the Endourological Society ureteroscopy global study

BACKGROUND

Ureteroscopy has traditionally been the preferred approach for treatment of distal and midureteral stones, with shock wave lithotripsy used for proximal ureteral stones.

OBJECTIVE

To describe the differences in the treatment and outcomes of ureteroscopic stones in different locations.

DESIGN, SETTING, AND PARTICIPANTS

Prospective data were collected by the Clinical Research Office of the Endourological Society on consecutive patients treated with ureteroscopy at centres around the world over a 1-yr period.

INTERVENTION

Ureteroscopy was performed according to study protocol and local clinical practice guidelines.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Stone location, treatment details, postoperative outcomes, and complications were recorded. Pearson's chi-square analysis and analysis of variance were used to compare outcomes among the different stone locations.

RESULTS AND LIMITATIONS

Between January 2010 and October 2012, 9681 patients received ureteroscopy treatment for stones located in the proximal ureter (n=2656), midureter (n=1980), distal ureter (n=4479), or multiple locations (n=440); location in 126 patients was not specified. Semirigid ureteroscopy was predominantly used for all stone locations. Laser and pneumatic lithotripsy were used in the majority of cases. Stone-free rates were 94.2% for distal ureter locations, 89.4% for midureter locations, 84.5% for proximal ureter locations, and 76.6% for multiple locations. For the proximal ureter, failure and retreatment rates were significantly higher for semirigid ureteroscopy than for flexible ureteroscopy. A low incidence of intraoperative complications was reported (3.8-7.7%). Postoperative complications occurred in 2.5-4.6% of patients and varied according to location, with the highest incidence reported for multiple stone locations. Limitations include short-term follow-up and a nonuniform treatment approach.

CONCLUSIONS

Ureteroscopy for ureteral stones resulted in good stone-free rates with low morbidity.

PATIENT SUMMARY

This study shows that patients who have ureteral stones can be treated successfully with ureteroscopy with a low rate of complications for the patient.

Efficacy of percutaneous nephrostomy during flexible ureteroscopy for renal stone management

PURPOSE

Preoperative percutaneous nephrostomy (PCN) can be applied to urinary stone patients with pyelonephritis as well as obstructive uropathy; thus, some patients undergo flexible ureteroscopy (fURS) in the presence of a PCN tube. We evaluated the effectiveness of PCN during fURS for the management of renal stones.

MATERIALS AND METHODS

We retrospectively analyzed 130 consecutive patients who underwent fURS for renal stones between January 2009 and December 2011. All fURS procedures were performed by a single experienced surgeon. The patients were divided into two groups depending on the presence of PCN during the surgery: patients with PCN (group 1, n=41) and patients without PCN (group 2, n=89). To evaluate operative outcomes, we compared success rates, operative times, and complication rates. We defined success as the absence of any residual stones in the kidney or stone fragments less than 2 mm that were too small to be extracted during follow-up.

RESULTS

There were no significant differences in age, sex, body mass index, stone laterality, burden, or location between the two groups. The mean operative times of groups 1 and 2 were 50.1 and 58.3 minutes, respectively (p=0.102). The success rates of groups 1 and 2 were 95.1% and 82.0%, respectively (p=0.044). There was no statistically significant difference in the complication rate between groups 1 and 2 (p=0.888).

CONCLUSIONS

Flexible ureteroscopy in the presence of PCN produced a superior outcome in terms of the success rate without increasing the operative time or complication rate. PCN may be helpful to induce better outcomes of fURS.

Computed tomography-based novel prediction model for the stone-free rate of ureteroscopic lithotripsy

The purpose of this study was to evaluate whether computed tomography (CT) parameters can predict the success of ureteroscopic lithotripsy (URSL) and establish a model for predicting the success rates of a single URSL procedure for the treatment of a single ureteral stone. We retrospectively reviewed the records of 237 patients who underwent URSL for ureteral stones diagnosed by CT between January 2009 and June 2012. Stone-free status was defined as the absence of stones or residual stone fragments <2 mm by ureteroscopy and plain abdominal radiography. We analyzed the correlations between the outcome of URSL and the patients' sex, age, height, body weight, body mass index, and history of ureteral stone. Stone factors such as the diameter (D), stone height (H), volumetric stone burden (VSB; D(2) × H × 5 mm × π × 1/6), estimated stone location (ESL; number of axial cut images between the stone and uretero-vesical junction), tissue rim sign (RS; 0-3), perinephric edema (0-3), hydronephrosis (0-3), and Hounsfield unit (HU) were also analyzed. We then developed a model to predict the probability of successful URSL by applying a logistic model to our data. The success rate of URSL was 85.7% (203/237). Univariate analysis found that stone diameter, length, VSB, ESL, HU and RS significantly affected the stone-free rate. Multivariate analysis indicated that stone diameter, ESL and RS independently influenced the stone-free rate. The logistic model indicated that success rates = 1/[1 + exp{-6.146 + 0.071(D) + 0.153(ESL) + 1.534(RS)}] with an area under the receiver operating characteristic curve of 0.825. Stone diameter, ESL, and RS were independent predictors of the outcome of a single URSL for a single ureteral stone.

The role of microperc in the treatment of symptomatic lower pole renal calculi

BACKGROUND AND PURPOSE

The treatment of symptomatic lower pole (LP) calculi poses a challenge because of lower clearance rates. We present our experience with microperc in the treatment of LP renal calculi.

PATIENTS AND METHODS

We retrospectively evaluated the symptomatic patients with LP renal calculi who underwent microperc between August 2011 and June 2012 from two referral hospitals. Patients were included only in cases of failure after shockwave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS) and according to patient preference. The percutaneous renal access was performed using the 4.8F "all-seeing needle" with C-arm fluoroscopy or ultrasonographic guidance with the patient in the prone position. Stone disintegration was established using a 200 μm holmium:yttrium-aluminum-garnet laser fiber.

RESULTS

A total of 21 patients (mean age 37.3 ± 20.1 years) with LP stone underwent microperc. The mean body mass index was 28.6 ± 6.0 kg/m(2), and the mean stone size was 17.8 ± 5.9 (9-29) mm. The duration of surgery and fluoroscopic screening was 62.8 ± 25.2 minutes and 150.5 ± 92.8 seconds, respectively. The patients were discharged after a mean 37.5 ± 14.4 hours of hospitalization time. The mean hemoglobin drop was 0.8 ± 0.6 (0.1-2.3) g/dL. Conversion to miniperc was necessitated in one patient with loss of vision. Stone-free status was achieved in 18 (85.7%) patients. Clinically insignificant residual fragments were observed in only one (4.8%). The procedure failed in two (9.5%) patients. A total of two minor complications (renal colic necessitating stent insertion and urinary tract infection) were observed postoperatively, none severe.

CONCLUSION

Microperc is a feasible and efficient treatment modality for symptomatic LP calculi. Our results provide that microperc might take a part in case of SWL and RIRS failures or as an alternative to percutaneous nephrolithotomy or RIRS in the management of symptomatic LP calculi.

Residual fragments following ureteroscopic lithotripsy: incidence and predictors on postoperative computerized tomography

PURPOSE

Residual fragments following ureteroscopy for calculi may contribute to stone growth, symptoms or additional interventions. We reviewed our experience with ureteroscopy for calculus disease to define the incidence and establish factors predictive of residual fragments.

MATERIALS AND METHODS

Records associated with 667 consecutive ureteroscopic lithotripsy procedures for upper urinary calculi were reviewed. In 265 procedures (40%) computerized tomography was done between 30 and 90 days postoperatively. They comprised the study group. Residual fragments were defined as any residual ipsilateral stone greater than 2 mm.

RESULTS

Included in the study were 121 men and 127 women with a mean age of 47 years. Mean target stone diameter was 7.6 mm. The stone location was the kidney in 30% of cases, ureter in 50%, and kidney and ureter in 20%. Residual fragments were detected on computerized tomography after 101 of 265 procedures (38%). Pretreatment stone size was associated with residual fragments at a rate of 24%, 40% and 58% for stones 5 or less, 6 to 10 and greater than 10 mm, respectively (p <0.001). Additionally, stone location in the kidney (p <0.001) or the kidney and ureter (p = 0.044), multiple calculi (p = 0.003), longer operative time (p = 0.008) and exclusive use of flexible ureteroscopy (p = 0.029) were associated with residual fragments. In a multivariate model only pretreatment stone diameter greater than 5 mm was independently associated with residual fragments after ureteroscopy (diameter 6 to 10 and greater than 10 mm OR 2.03, p = 0.03 and OR 3.74, p = 0.003, respectively).

CONCLUSIONS

Of patients who underwent ureteroscopic lithotripsy for calculi 38% had residual fragments by computerized tomography criteria, including more than 50% with stones 1 cm or greater. Such data may guide expectations regarding the success of ureteroscopy in attaining stone-free status.

Ureteroscopy with laser lithotripsy for urolithiasis in the spinal cord injury population

STUDY DESIGN

Retrospective study.

OBJECTIVES

The purpose of this investigation was to review the outcomes and safety of retrograde ureteroscopic laser lithotripsy (URS) for the treatment of urolithiasis in the spinal cord injury (SCI) population.

SETTING

Virginia, USA.

METHODS

All patients with SCI who underwent URS with holmium:YAG laser lithotripsy for urolithiasis over a 15-year period were identified. Stone size, location and number at presentation were recorded. Information regarding patient characteristics, intra-operative complications, surgical efficacy, stone clearance, peri-operative complications, and follow-up stone events was collected and analyzed.

RESULTS

A total of 67 URS procedures were performed on 29 SCI patients during the study period with an average follow-up of 3.4 years. Patients had an average of 2.3 ipsilateral ureteroscopies. The majority (85.1%) used indwelling catheters for long-term bladder management, and complete stone clearance after the first procedure was 34.3%. Of the 44 cases with residual stones >4 mm, 20 (45.5%) were secondary to technical or procedural limitations. The intra-operative complication rate was comparable to non-SCI studies at 1.5%, but peri-operative complications were significantly higher at 29.9% with the majority due to urosepsis. Factors associated with peri-operative complications include chronic obstructive pulmonary disease, motor incomplete injuries and lack of a pre-operative ureteral stent.

CONCLUSION

URS in the SCI population is an effective treatment for ureteral or renal stones but may be associated with greater risks and reduced efficacy.

Flexible ureteroscopy and laser lithotripsy for bilateral multiple intrarenal stones: is this a valuable choice?

OBJECTIVE

To demonstrate the safety and efficacy of flexible ureteroscopy (FURS) and holmium laser lithotripsy as a valuable treatment of bilateral multiple intrarenal stones and stratify the efficacy by stone burdens ≤ 20 and >20 mm.

METHODS

Twenty-five patients with bilateral multiple intrarenal stones were treated with FURS and holmium lithotripsy at a single clinic. The operative time, stone-free rates (SFRs) per renal unit, stone compositions, number of procedures, serum creatinine, and complications were evaluated. The SFRs were evaluated with computed tomography and plain X-rays of the kidneys, ureters, and bladder. Renal ultrasound was performed 30 days after double-J stent removal to identify hydronephrosis and absence of stones. We defined a stone-free status as the absence of fragments in the kidney or fragments of <1 mm.

RESULTS

The total stone number was 128 with a mean stone burden per patient of 24 ± 5 (range 17-37 mm). The overall SFRs per renal unit after 1, 2, and 3 procedures were 70.0%, 92.0%, and 92.0%, respectively. The overall SFRs per renal unit for patients with a preoperative stone burden ≤ 20 and >20 mm were 100% and 85.7%, respectively. No major intraoperative or postoperative complications occurred. There were only 4 minor postoperative complications (16%).

CONCLUSION

Our study results firmly suggest that FURS with holmium laser lithotripsy represents a favorable alternative to external shock wave lithotripsy or percutaneous nephrolithotomy for select patients with bilateral multiple intrarenal stones, which have a satisfactory efficacy and low morbidity.

Management of single large nonstaghorn renal stones in the CROES PCNL global study

PURPOSE

We compared stone characteristics and outcomes in patients with a single large nonstaghorn renal calculus treated with percutaneous nephrolithotomy in the Clinical Research Office of Endourological Society global study.

MATERIALS AND METHODS

Two statistical analyses were done, including one comparing renal stone size (20 to 30, 31 to 40 and 41 to 60 mm) and the other comparing renal stone site (pelvis, or upper, mid or lower calyx). Surgical outcomes, including operative time, hospital stay, stone-free rate and postoperative fever, were compared between groups. Fitness for surgery was assessed using the American Society of Anesthesiologists scoring system. Severity of postoperative complications was graded with the modified Clavien classification.

RESULTS

Of 1,448 stones 1,202 (83%) were 20 to 30 mm, 202 (14%) were 31 to 40 mm and 44 (3%) were 41 to 60 mm. Of the large stones 73% were located in the renal pelvis. A statistically significantly lower stone-free rate, and higher postoperative fever and blood transfusion rates were seen with increased calculous size. With increased American Society of Anesthesiologists score the proportion of large stones in the calyces increased. At a score of III the proportion of large stones in the calyces was more than twice that of stones in the renal pelvis (13.5% vs 5.7%). Generally more patients with large calyceal than large pelvic stones had postoperative complications across the range of Clavien scores from I to IIIB.

CONCLUSIONS

Calyceal site was associated with decreased fitness for surgery and an increased risk of postoperative complications compared to renal site. An increase in stone size results in a lower stone-free rate, and higher rates of postoperative fever and blood transfusion.

Acute postoperative pain after ureteroscopic removal of stone: incidence and risk factors

Purpose

Ureteroscopic removal of stones (URS) has been widely used to treat ureteral stones because it is comparatively safe, has a high success rate, and enables patients to rapidly return to their daily routines. However, some patients experience pain after URS, but the incidence of acute post-URS pain remains largely unknown. This study aimed to investigate the incidence of acute postoperative pain after URS and the associated risk factors.

Materials and Methods

Data for 143 consecutive patients who underwent URS from June 2008 to December 2010 were collected. After excluding 8 patients who developed intraoperative complications, the patients were divided into two groups according to postoperative pain on the first postoperative day. Acute postoperative pain was defined as a pain score greater than 4 on a visual analogue pain scale (normal range, 0 to 10). Various factors were analyzed to identify the risk factors that could predict acute postoperative pain after URS.

Results

The stone-free rate without URS intraoperative complications was 95.5%. A total of 21 (14.6%) patients experienced postoperative pain on the first postoperative day. Young age, psychiatric illness, history of urinary tract infection, use of a stone basket, large stone size, and prolonged operation time were identified as risk factors for acute postoperative pain.

Conclusions

The incidence of acute postoperative pain is not that low and should not be overlooked, because it is associated with postoperative complications that could result in an unscheduled hospital admission or visit. Active pain control should be contemplated after URS in young patients and in those with a history of urinary tract infection, psychiatric illness, large stone size, and prolonged operation time.

Ureterorenoscopy with holmium-yttrium-aluminum-garnet fragmentation is a safe and efficient technique for stone treatment in patients with a body mass index superior to 30 kg/m2

PURPOSE

The aim of the study was to analyze results and morbidity after flexible ureterorenoscopy in patients with a body mass index (BMI) >30 kg/m(2) and to compare with results obtained in a large cohort of nonobese patients.

PATIENTS AND METHODS

We conducted a retrospective study including all flexible ureterorenoscopy performed for stone retrieval in our institution between January 2004 and December 2008. During the study period, 224 procedures were performed, of which 18 had to be excluded because of missing BMI data. Thus, a total of 206 procedures were included in the final analysis (34 in 29 obese patients, 172 in 149 nonobese patients). Characteristics of the patients (age, BMI, previous treatment), stones (nature, location, number), and procedures (operating time, morbidity, outcome) were analyzed. Success was defined as clear imaging (completely stone free) on renal tomography and ultrasonography at 1, 3, and 6 months follow-up.

RESULTS

Mean BMI was 34±0.6 kg/m(2) in obese patients (OP) and 24±0.2 kg/m(2) in nonobese patients (NOP). Mean stone size, location, and composition were not significantly different between groups. Operative time was also similar in OP and NOP (102.5±6.1 min vs 103±3.4 min, P=NS). The rate of minor complications (fever, hematuria, flank pain) was similar in OP (11.8%) and NOP (11.4%). No major complication necessitating prolonged hospital stay or new surgical procedure was observed. The overall stone-free rate was not significantly different between OP (79.4%) and NOP (70%).

CONCLUSION

Flexible ureterorenoscopy is an appropriate treatment for use in obese patients and achieves excellent stone-free rates with low morbidity.

Ureteroscopic retrograde intrarenal surgery after previous open renal stone surgery: initial experience

The management of renal calculi following previous open surgery represents a challenge for urologists. The aim of this study is to evaluate the outcomes and safety of ureteroscopic laser retrograde intrarenal surgery (RIRS) for renal calculi following prior open renal surgery. The charts of 53 patients who underwent RIRS for renal calculi following prior open surgery for urolithiasis were reviewed. Both flexible and semi-rigid ureteroscopes were utilized together with holmium: YAG laser for stone disintegration. Intravenous urography, computed tomography (CT) and ultrasound were used to evaluate the patient, perioperatively. Stone size ranged from 5 to 32 mm (mean 14.3 mm). The mean operative time was 86 min (20-130). The overall stone-free rate was 92.4%. The overall stone-free rates after one and two-procedures were 79.2% (42 cases) and 92.4% (49 cases), respectively. Four patients (7.5%) had larger residual fragments, 2 (3.8%) of them underwent SWL, and 2 (3.8%) cases were followed up conservatively. Major complications were reported in two patients (3.8%). Stone analysis revealed calcium oxalate in 39 patients, uric acid in 5, calcium phosphate in 4, struvite in 3, and cystine in 2 cases. Ureteroscopic retrograde intrarenal surgery for renal calculi following prior open renal surgery was a minimally invasive, safe procedure with a high success rate. It is a viable alternative for PNL in managing recurrent renal calculi efficiently.

Flexible ureteroscopy update: indications, instrumentation and technical advances

Retrograde ureteroscopy has recently gained a broadened indication for use from diagnostic to a variety of complex minimally invasive therapies. This review aims to look at the recent advances in the instrumentation and accessories, the widened indications of its use, surgical techniques and complications. With minimization of ureteroscopic instruments manufacturers are challenged to develop new, smaller and sturdier instruments that all will also survive the rigors of surgical therapy.

Current status of retrograde intrarenal surgery for management of nephrolithiasis in children

Purpose

To review the current status of retrograde intrarenal surgery (RIRS) for renal stones in children focusing on its indications, outcomes and success in the management of nephrolithiasis.

Materials and Methods

Between 1988 and 2009, a comprehensive PubMed/MEDLINE literature review on RIRS was conducted.

Results

The available literature is limited and heterogeneous, skewed by favorable results on ureteral stone outcomes. However, recent case series report outcomes comparable to time-honored modalities: percutaneous nephrolithotomy and shock wave lithotripsy. Concerns about urinary tract damage are not substantiated by the yet available intermediate-term follow-up.

Conclusions

RIRS seems to be an effective modality in pediatric nephrolithiasis management. However, long-term outcomes and comparative prospective randomized studies are awaited.

Lower pole calculi larger than one centimeter: Retrograde intrarenal surgery

Controversy remains on how to treat lower pole calculi between 1 and 2 cm of size. Treatment options like shock wave lithotripsy (SWL) or percutaneous stone treatment (PCNL) are associated with poor stone-free rates or high morbidity.

Due to the ongoing development in endourologic technology, especially in flexible renoscopy, laser technique and grasping devices (tipless Nitinol baskets) retrograde intrarenal surgery (RIRS) has become an option in treating these patients.

Based on personal experience and an overview of the published literature we discuss RIRS as a valuable alternative to PCNL in treating patients with larger calculi of the lower pole.

The technical developments in laser technology as well as significant improvement in flexible renoscopes have made RIRS for larger lower pole stones possible. The low complication rate gives RIRS for lower pole stones superiority over the invasive percutaneous approach, which is associated with significant morbidity, even in experienced hands.

Ureterorenoscopy: avoiding and managing the complications

Retrograde exploration of the ureter and kidneys is currently a widely used and well-established procedure to deal with problems of a diagnostic and therapeutic nature with reduced invasiveness. The process of miniaturizing the instruments combined with the steady improvement in video quality has continuously amplified its potential applications, maintaining the procedure safe and rapid. During an operation, however, unexpected events may condition a change to the programme or determine the onset of even more serious complications. Our aim is to analyze such events and complications and recommend potential solutions to prevent and/or deal with such happenings.

Effectiveness of single flexible ureteroscopy for multiple renal calculi

PURPOSE

To assess effectiveness of flexible ureteroscopy (fURS) in patients not with simple but with multiple unilateral renal stones.

PATIENTS AND METHODS

A database analysis was performed to identify patients with multiple unilateral intrarenal stones. Patients were treated using an 8.8F flexible ureteroscope. Patients were considered stone free if no residual stones were seen endoscopically and radiographically after the procedure. The efficiency and the safety of the procedures were analyzed.

RESULTS

Between 2006 and 2008, 1054 ureteroscopic procedures were performed in our department; 125 patients met the inclusion criteria. Holmium:yttrium-aluminum-garnet laser lithotripsy was necessary in 41 (32.8%) patients. The mean stone size was 11.93 ± 8.2 mm, with a mean stone burden of 83.7 ± 67.66 mm(2). The mean number of stones was 3.59 ± 3.57. Twenty-six (20.8%) patients had a stone burden ≥ 100 mm(2), and 99 (79.2%) a stone burden <100 mm(2). The overall stone-free rate after a single procedure of fURS was 74.4%. In the remaining 32 patients with residual stones, the mean stone burden dropped from 123.24 ± 84.36 mm(2) to 56.28 ± 52.53 mm(2). The stone-free rate in patients with a stone burden ≥ 100 mm(2) was 65.4% and 79.5% in patients with a stone burden < 100 mm(2), respectively. Complications have been recorded in seven (5.6%) patients, including urinary tract infection in four, ureteral perforation in one, and hematuria in two patients. No major complications occurred. All patients were treated conservatively.

CONCLUSIONS

fURS is an effective treatment option in patients with multiple unilateral renal stones. Single procedure stone-free rates are high with a low rate of only minor complications.

Percutaneous nephrolithotomy versus extracorporeal shock wave lithotripsy for moderate sized kidney stones

OBJECTIVE

To compare the outcomes of percutaneous nephrolithotomy (PNL) and extracorporeal shock wave lithotripsy (ESWL) for moderate sized (1-2 cm) upper and middle pole renal calculi in regards to stone clearance rate, morbidity, and quality of life.

METHODS

All patients diagnosed with moderate sized upper and middle pole kidney stones by computed tomography (CT) were offered enrollment. They were randomized to receive either ESWL or PNL. The SF-8 quality of life survey was administered preoperatively and at 1 week and 3 months postoperatively. Abdominal radiograph at 1 week and CT scan at 3 months were used to determine stone-free status. All complications and outcomes were recorded.

RESULTS

PNL established a stone-free status of 95% and 85% at 1 week and 3 months, respectively, whereas ESWL established a stone-free status of 17% and 33% at 1 week and 3 months, respectively. Retreatment in ESWL was required in 67% of cases, with 0% retreatment in PNL. Stone location, stone density, and skin-to-stone distance had no impact on stone-free rates at both visits, irrespective of procedure. Patient-reported outcomes, including overall physical and mental health status, favored a better quality of life for patients who had PNL performed.

CONCLUSION

PNL more often establishes stone-free status, has a more similar complication profile, and has similar reported quality of life at 3 months when compared with ESWL for moderate-sized kidney stones. PNL should be offered as a treatment option to all patients with moderate-sized kidney stones in centers with experienced endourologists.

Immediate unplanned hospital admission after outpatient ureteroscopy for stone disease

PURPOSE

Medicare recently changed reimbursement for ureteroscopy, encouraging migration to ambulatory surgical centers. To our knowledge the risk of immediate unplanned hospital admission, which may discourage ureteroscopy at ambulatory surgical centers, is unknown. We determined the rate of immediate unplanned hospital admission, identified factors associated with admission and developed a risk stratification tool to assist with location selection for outpatient ureteroscopy.

MATERIALS AND METHODS

We retrospectively reviewed the records of 1,798 consecutive outpatient ureteroscopic procedures for urolithiasis performed from 1998 to 2008 at our institution. Patients requiring immediate hospital admission were matched 1 to 3 by provider, gender and date with controls who did not require admission. Patient demographics, comorbid conditions, stone history and burden, and operative technique were assessed for impact on admission by bivariate and multivariate logistic regression. A scoring system was developed and estimated admission rates were calculated.

RESULTS

There were 70 immediate unplanned admissions (3.9%). Based on multivariate analysis the factors associated with unplanned admission were any previous admission related to stones (p <0.001), history of psychiatric illness (p = 0.016) and bilateral procedure (p = 0.019). Patients with distal ureteral stones were less likely to require admission (p = 0.026). One point was added for each positive factor and 1 was subtracted for a distal ureteral stone. A risk factor score of 2 or greater in 9% of the cohort was associated with an estimated 20.0% admission rate while lower scores in 91% of the cohort were associated with a 2.9% admission rate.

CONCLUSIONS

Readily identifiable factors can stratify the risk of unplanned hospital admission and help guide the selection of the most appropriate facility for outpatient ureteroscopy.

Contralateral ureteroscopy performed at percutaneous nephrolithotomy: a unique evaluation of stone-free rates

PURPOSE

Immediate stone-free rates of ureteroscopy are rarely reported. To establish accurate stone-free rates after ureteroscopy we assessed the safety and success of ureteroscopy for patients undergoing the procedure at contralateral percutaneous nephrolithotomy.

MATERIALS AND METHODS

From our prospectively collected, institutional review board approved, percutaneous nephrolithotomy database we identified patients who underwent contralateral ureteroscopy for urolithiasis at percutaneous nephrolithotomy from December 2001 to December 2008. Stone-free status was assessed with noncontrast computerized tomography on postoperative day 1.

RESULTS

A total of 65 patients underwent ureteroscopy for urolithiasis at contralateral percutaneous nephrolithotomy. There were 63 patients available for review who had noncontrast computerized tomography on postoperative day 1. Immediate stone-free status was achieved after ureteroscopy in 37 of 63 patients (58.7%). The remaining 26 patients (41.3%) demonstrated a residual stone burden. Of these patients with residual stones after ureteroscopy 65.4% (17 of 26) had residual fragments of 1 to 3 mm and 34.6% (9 of 26) had residual stones larger than 3 mm. Three patients (4.8%) underwent repeat ureteroscopy at secondary percutaneous nephrolithotomy. There was no association of stone composition, patient age, stone location, gender or surgical complications with residual fragments (p>0.05).

CONCLUSIONS

Based on noncontrast computerized tomography 58.7% of patients who underwent ureteroscopy were rendered immediately stone-free. When residual passable stone fragments less than 3 mm were included the success rate increased to 85.7%. We found no association between characteristics of patients, stones or procedures and residual fragments.

Flexible ureteroscopy and laser lithotripsy for multiple unilateral intrarenal stones

BACKGROUND

External shock wave lithotripsy (ESWL) and percutaneous nephrolithotomy (PNL) have been the standard of care for the treatment of intrarenal calculi.

OBJECTIVE

We sought to determine the safety and efficacy of flexible ureteroscopy and holmium laser lithotripsy for the treatment of multiple intrarenal calculi and further stratify the efficacy by stone burden less than and greater than 20mm.

DESIGN, SETTING, AND PARTICIPANTS

Patients with multiple unilateral renal calculi treated between 2000 and 2006 at a single tertiary academic center were retrospectively evaluated.

INTERVENTION

All patients underwent retrograde flexible ureteroscopy and holmium laser lithotripsy.

MEASUREMENTS

Stone-free status was determined by ureteroscopy 15 d after the last procedure and was defined as the absence of stones in the kidney or residual fragments <1mm. A renal ultrasound was performed 30 d after the last treatment to confirm the absence of stones and hydronephrosis.

RESULTS AND LIMITATIONS

Fifty-one patients were identified for a total of 161 intrarenal calculi with a mean stone size per patient of 6.6+/-3mm (range: 2-15). The mean number of stones per patient was 3.1+/-1 (range: 2-6). The mean number of primary procedures was 1.4+/-0.6 (range: 1-3). The overall stone-free rates after one and two procedures were 64.7% and 92.2%, respectively. The stone-free rates for patients with a stone burden greater than and less than 20mm were 85.1% and 100%, respectively. The overall complication rate was 13.6%; 97.6% of cases were performed as outpatient procedures. There are some limitations to this study, however: This is a retrospective review from a single institution, and our results are based on a relatively small sample size.

CONCLUSIONS

For select patients with multiple intrarenal calculi, flexible ureteroscopy with holmium laser lithotripsy may represent an alternative therapy to ESWL or PNL, with acceptable efficacy and low morbidity.