Asymptomatic Residual Fragments Research Articles

A Decision Analysis of Observation vs Immediate Reintervention for Asymptomatic Residual Fragments Less than 4 mm Following Ureteroscopic Lithotripsy.

We performed a decision analysis model of the cost-effectiveness of observation vs intervention for asymptomatic residual fragments less than 4 mm in diameter following ureteroscopic holmium laser lithotripsy. Outcomes data from a retrospective analysis evaluating the natural history, complications and reintervention rates of asymptomatic residual stone fragments performed by the EDGE (Endourology Disease Group for Excellence) Research Consortium were used. A decision analysis model was constructed to compare the cost-effectiveness of initial observation of residual fragments to immediate intervention. Cost of observation included emergency room visits, hospitalizations and reinterventions. The cost analysis model extended to 3 years to account for delayed reintervention rates for fragments less than 4 mm. Costs of emergency department visits, readmissions and reinterventions were calculated based on published figures from the literature. Decision analysis modeling demonstrated that when comparing initial observation to immediate reintervention, the cost was $2,183 vs $4,424. The difference in cost was largely driven by the fact that over 3 years, approximately 55% of all patients remained asymptomatic and did not incur additional costs. This represents an approximate annual per patient savings of $747, and $2,241 over 3 years when observation is selected over immediate reintervention. Our decision analysis model demonstrates superior cost-effectiveness for observation over immediate reintervention for asymptomatic residual stones less than 4 mm following ureteroscopic lithotripsy. Based on these findings careful stratification and selection of patients may enable surgeons to improve cost-effectiveness of managing small, asymptomatic residual fragments following ureteroscopic lithotripsy.

Les scores radiologiques peuvent-t-ils prédire le succès de la NLPC ? Étude comparative du Guy's stone score, du STONE score, du CROES nomogram, et du S-ReSc score

The aim of the study is to investigate the factors predictive of surgical outcomes of PCNL and to compare the predictability and accuracy of the Guy's stone score, STONE nephrolithometry, CROES nomogram and S-ReSC score. We reviewed retrospectively the surgical outcomes recorded consecutively and imaging data of preoperative computed tomography scans of patients who underwent PCNL from 2013 to 2016. Patients with asymptomatic residual fragments<4mm were considered stone-free. Preoperative abdominopelvic computerized tomography images of the patients were reviewed and scored according The Guy's stone score, STONE nephrolithometry, CROES nomogram, S-ReSC score by one urologist. A total of 157 PCNLs were reviewed. The overall stone-free rate was 59% (92/157) with a complication rate of 22% (35/157). Stone Burden<542mm3 is significantly associated with stone-free rate (SFR) (P=0.001). On univariate analysis, all the scoring systems were identified as significant factors in terms of SFR. The Guy's Stone Score, the CROES score and the S-ReSC score were associated with complications (P<0.02). The multivariate logistic regression analysis showed that the CROES score was identified as a significant factor in terms of SFR and complications (P<0.01). The area under the receiver operating characteristic (ROC) curves for stone burden, the Guy's, STONE score, CROES core and S-ReSC scores showed good results (0.737/0.674/0.762/0.746/0.710) respectively. Although the four scoring systems were significantly associated with SFR, the STONE score was a significant predictive factor for SFR and complications after PCNL. 3.

Management of Clinically Insignificant Residual Fragments following Shock Wave Lithotripsy

Clinically insignificant residual fragments (CIRFs) are small fragments (less than 5 mm) that are present in upper urinary tract at the time of regular post-SWL followup. The term is controversial because they may remain silent and asymptomatic or become a risk factor for stone growth and recurrence, leading to symptomatic events, and need further urologic treatment. Although a stone-free state is the desired outcome of surgical treatment of urolithiasis, the authors believe that the presence of noninfected, nonobstructive, asymptomatic residual fragments can be managed metabolically in order to prevent stone growth and recurrence. Further urologic intervention is warranted if clinical indications for stone removal are present.

Retrograde Intrarenal Surgery Versus Percutaneous Nephrolithotomy in the Management of Lower-Pole Renal Stones with a Diameter of 15 to 20 mm

To compare the outcomes of percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) for 15 to 20 mm lower-pole (LP) renal calculi by evaluating stone-free rates and associated complications. The records of 79 patients who underwent either PCNL (n=42) or RIRS (n=37) by standard techniques for 15 to 20 mm LP renal calculi were reviewed retrospectively. In the PCNL group, the stone-free rate was 92.8% (39/42 patients); this rate increased to 97.6% after a second intervention (shockwave lithotripsy in one and RIRS in one). After a single RIRS procedure, 33 of 37 (89.2%) patients were completely stone free. Two patients needed an additional procedure (rigid ureteroscopy in one and RIRS in one), after which they were all completely stone free, resulting in an overall success rate of 94.6%. Two patients had asymptomatic residual fragments <7 mm in the LP of the kidney, and these patients had been followed with ultrasonography of the kidney. For complications, there were minimal differences in both procedures, except for hemorrhage (necessitated transfusion) in three patients who were treated with PCNL. The overall stone-free rates and complication rates for PCNL were higher, but the differences were not statistically significant. Operative time was significantly longer in the RIRS group, and postoperative hospital stay was significantly longer in PCNL group. PCNL and RIRS are safe and effective methods for medium-sized LP calculi. For selected patients, RIRS may represent an alternative therapy to PCNL, with acceptable efficacy and low morbidity.

The Natural History of Renal Stone Fragments Following Ureteroscopy

To describe the natural history of postureteroscopic renal stone fragments ≤4 mm based on computed tomography (CT) follow-up. The goal of ureteroscopy is to fragment stones, actively basket and remove fragments larger than 1 mm, and allow the remaining fragments to pass spontaneously. The reality is that smaller fragments may be difficult to extract or may be missed. Patients treated with ureteroscopy and holmium laser lithotripsy for urolithiasis by a single surgeon from May 2001 to July 2008 at a tertiary referral center were identified. Patients with residual renal fragments measuring ≤4 mm on initial postoperative CT and at least one additional follow-up CT were included. Outcomes measured were fragment growth and location, stone event (emergency department visit, hospitalization, or additional intervention), and spontaneous fragment passage. Of 330 ureteroscopies, 51 met inclusion criteria. For these patients, the mean follow-up duration was 18.9 months (1.6 years). Among 46 ureteroscopies for calcium-based stones, 9 patients (19.6%) experienced a stone event, 10 patients (21.7%) spontaneously passed their fragments, and the remaining 27 patients (58.7%) retained asymptomatic residual fragments. Among this asymptomatic group, mean fragment sizes were similar at 2.7, 3.3, 3.5, and 3.0 mm at mean follow-up durations of 2.8, 10.2, 16.8, and 33.0 months, respectively. This study suggests that among patients with postureteroscopic renal stone fragments ≤4 mm, approximately one in five (or 19.6%) will experience a stone event over the following 1.6 years. The remaining patients will either become stone-free via spontaneous passage or retain asymptomatic stable-sized fragments.

Clinical Insignificant Residual Fragments (CIRF) after Extracorporeal Lithotripsy: Implications and Treatment

The stone-free status depends on the appropriate selection of the urologic treatment according to the stone and excretory tract characteristics, and/or to the patient parameters. Although the gold standard for the treatment is the stone-free status, the authors believe that the presence of non-infected, nonobstructive, asymptomatic residual fragments, smaller than 4–5 mm, can be treated with an adequate medical therapy in order to prevent stone growth. Further urological treatment is recommended if the clinical indications for stone removal persist.

MONOTHERAPY EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY FOR THE TREATMENT OF STAGHORN CALCULI IN CHILDREN

We evaluate the efficacy and parenchymal consequences of extracorporeal shock wave lithotripsy (ESWL) for staghorn calculi in children. From 1991 to 1999, 16 young patients 5.5 months to 2 years old and 7 older children 6 to 11 years old were treated for complete (6) or partial (17) staghorn calculi. Infection was the main factor of lithogenesis, particularly in younger children. In 21 patients the stone burden was more than 20 mm. All patients were treated under general anesthesia using a 14 kV. Sonolith 3000 (14) or a 12 to 20 kV. Nova (9) lithotriptor. In 5 of the 7 older children a Double J section sign stent was inserted before treatment. In the younger children group calculi were fragmented after 1 (11) or 2 (5) sessions. Of the 7 older children 3 required 3 (1) and 4 (2) treatment sessions. To assess the long-term effect of ESWL on the parenchyma, dimercapto-succinic acid renal scan was performed the day before and 6 months after therapy in 20 patients. Of the 16 younger children 14 became stone-free (87.5%) and 2 had small asymptomatic residual fragments. Of the 7 older children 5 were stone-free (71.4%) and 2 required additional surgery. No steinstrasse or pyelonephritis occurred after ESWL and no parenchymal or ureteral lesion related to ESWL was identified on conventional dimercapto-succinic acid scintigraphy. At a followup of 9 months to 9 years all patients have normal blood pressure. ESWL as a first option is safe and appropriate for the treatment of staghorn calculi in children particularly in younger children with infected calculi.

Monotherapy extracorporeal shock wave lithotripsy for the treatment of staghorn calculi in children.

We evaluate the efficacy and parenchymal consequences of extracorporeal shock wave lithotripsy (ESWL) for staghorn calculi in children. From 1991 to 1999, 16 young patients 5.5 months to 2 years old and 7 older children 6 to 11 years old were treated for complete (6) or partial (17) staghorn calculi. Infection was the main factor of lithogenesis, particularly in younger children. In 21 patients the stone burden was more than 20 mm. All patients were treated under general anesthesia using a 14 kV. Sonolith 3000 (14) or a 12 to 20 kV. Nova (9) lithotriptor. In 5 of the 7 older children a Double J section sign stent was inserted before treatment. In the younger children group calculi were fragmented after 1 (11) or 2 (5) sessions. Of the 7 older children 3 required 3 (1) and 4 (2) treatment sessions. To assess the long-term effect of ESWL on the parenchyma, dimercapto-succinic acid renal scan was performed the day before and 6 months after therapy in 20 patients. Of the 16 younger children 14 became stone-free (87.5%) and 2 had small asymptomatic residual fragments. Of the 7 older children 5 were stone-free (71.4%) and 2 required additional surgery. No steinstrasse or pyelonephritis occurred after ESWL and no parenchymal or ureteral lesion related to ESWL was identified on conventional dimercapto-succinic acid scintigraphy. At a followup of 9 months to 9 years all patients have normal blood pressure. ESWL as a first option is safe and appropriate for the treatment of staghorn calculi in children particularly in younger children with infected calculi.

Flexible ureterorenoscopy for the treatment of refractory upper urinary tract stones.

To report our experience of using flexible ureterorenoscopy for upper urinary tract stones. Thirty-seven patients (13 females, 24 males, mean age 48 years, range 10-76) with upper urinary tract stones not responding to other treatments had their residual symptomatic stones treated through a 9.3 F flexible ureterorenoscope. Electrohydraulic lithotripsy (EHL) was used to fragment the stones and a basket or a grasper used to retrieve the fragments. Twenty-three patients were completely freed of stone and a further five had asymptomatic residual fragments of < 5 mm. Of 15 patients with ureteric stones, 14 were rendered stone-free at the end of the procedure and 14 of the 22 patients with kidney stones were treated successfully; 80% of the lower calyceal stones were treated successfully and a firm decision was possible on the further management of the remaining stones. There were no major complications. Flexible ureterorenoscopy should be considered in patients with symptomatic upper ureteric or renal stones refractory to other treatments, but the instrumentation is expensive and delicate, and its use should be reserved for such cases.

Transurethral Ureterolithotomy in 100 Lower Ureteral Stones

A total of 100 patients with lower ureter stones received transurethral ureterolithotripsy (TUL) using a pulsed dye laser and/or a pneumatic lithotriptor. Extracorporeal shock wave lithotripsy treatment was added in 15 patients because fragments larger than 4 mm had been pushed back to the renal pelvis. The median stone size was 8 mm (range 3–22 mm). Operative time ranged between 3 and 157 min with a median of 30 min. Stone size correlated well with impaction, when impaction was defined as the inability of a guidewire to pass over the stone. Complete removal was defined as total clearance at 1 month without retreatment. The overal stone-free rate was 93%. Among the 7 not-stone-free cases, 5 cases were considered to have been treated successfully because asymptomatic residual fragments were smaller than 4 mm, 1 case required retreatment to become stone free, and 1 case with a silent residual fragment of 8 mm had been followed up for 3 months. The success rate was 98% when successful treatment was defined as total clearance or the presence of asymptomatic residual fragments of 4 mm or less without retreatment. Impaction was not a significant determining factor of stone-free rate (95.7 and 86.7%, respectively, p >0.05) and in situ stone-free rate (TUL alone; 85.7 and 76.7%, respectively, p >0.05). Two minor ureteral perforations were encountered. No patient required percutaneous nephrostomy or open surgery, or showed any late complications. TUL is a safe and successful method in managing lower ureteral stones.

Extracorporeal Shockwave Lithotripsy in Anomalous Kidneys

Traditionally, stones in anomalous kidneys have been removed by open or percutaneous surgery. Extracorporeal shockwave lithotripsy (SWL) with the Dornier MPL 9000 lithotripter was performed in seven patients with horseshoe kidneys, four with pelvic ectopic kidneys, and six with malrotated kidneys. Twelve patients (71%) needed repeated treatments. A total of 11 patients (65%) in all the groups were stone free, and four patients had asymptomatic residual fragments no more than 5 mm in diameter. In the remaining two patients, no sign of stone disintegration was observed, and they underwent open surgery. Extracorporeal lithotripsy is the treatment of choice for stones in horseshoe or malrotated kidneys but is not useful for stones in most pelvic kidneys.

Treatment of Renal and Ureteral Stones with Lithocut C-3000 Lithotripter

Extracorporeal shock wave lithotripsy is nowadays the first-line treatment of both renal and ureteral stones. Lithotripters are still expensive, but marked reduction of treatment costs can be achieved with simpler, less costly equipment and treatment on an outpatient basis without anesthesia. We present 213 consecutive evaluable cases treated with the new Swedish lithotripter Lithocut C-3000. Successful fragmentation, defined as patients becoming stone free or having only asymptomatic residual fragments of ≤4 mm at 1- to 3-month follow-up, occurred in 87% of pelvic stones, 84% of caliceal stones, and 83% of proximal ureteral stones. Midureteral and distal ureteral stones were eliminated in approximately 55% of the cases. Location of stones is made by means of independent C-arm X-ray equipment, and ultrasound can be mounted as an option. The treatment was made without anesthesia, and one third of the patients were treated on an outpatient basis. The good clinical results, the reasonable purchase price, and the low running costs make the Lithocut C-3000 a competitive, easy-to-handle alternative machine for urologic centers that do not have large case loads.

Extracorporeal Piezoelectric Lithotripsy: Experience in 930 Patients

We treated 930 patients with a Wolf Piezolith 2300 piezoelectric lithotripter using ultrasound stone location and completed a 3-month follow-up. Most (80.7%) of the 986 renoureteral units had solitary stones; of the stones, 74.9% were renal, 21.9% ureteral, and 3.2% both. Preoperative manipulations were limited as much as possible, and ureteral stones were treated in situ. No anesthesia was given. One percent of patients required analgesics because of pain during treatment. Slightly more than half (56.4%) required more than one treatment session, and the average number of sessions was 2.4. The overall success rate was 90.1% (range 95.7% for stones 5-10 mm in diameter; 61% for stones >30 mm). The stone-free rate was 77.5%; the rate of asymptomatic residual fragments under 4 mm in diameter was 12.6%. Morbidity was low and related to stone size. Obstructing ureteric fragments occurred in 56 renoureteral units, 44 of which were successfully treated with extracorporeal shock wave lithotripsy alone and 12 of which required ancillary procedures. Three subcapsular hematomas were detected. Ultrasound stone location limits ureteral stone lithotripsy to upper and lower ureteral calculi. Piezoelectric lithotripsy is a safe and efficient procedure for the treatment of urinary stones.

Lithostar Extracorporeal Shock Wave Lithotripsy: The First 1,000 Patients

To our knowledge this study of our first consecutive 1,000 patients treated with the Siemens Lithostar device is the largest prospective series reported to date. Treatment results were determined at 3,12 and 24 months after completion of therapy. The results at 3 months are presented. Complete followup data were available on 801 patients: 674 with renal and 127 with ureteral calculi. Results were analyzed according to stone size, location and number. The average number of shocks per treatment was 3,804 and the retreatment rate was 18.6%.At 3 months the stone-free rate was determined by a plain film of the kidneys, ureters and bladder and plain tomograms for renal calculi, and by an excretory urogram for ureteral calculi. The stone-free rate was 52% for renal and 76% for ureteral calculi. The overall stone-free rate for all calculi was 55.7%. Success rate, defined as stone-free or asymptomatic residual fragments measuring 4mm. or less, was 72% for renal and 83% for ureteral calculi. The overall success rate for all calculi was 73.9%.

Comparison of Results and Morbidity of Percutaneous Nephrostolithotomy and Extracorporeal Shock Wave Lithotripsy

Two new therapies, percutaneous nephrostolithotomy and extracorporeal shock wave lithotripsy, are revolutionizing the treatment of upper urinary tract calculi. We report the success and morbidity rates in 110 patients undergoing percutaneous nephrostolithotomy and 982 patients treated with extracorporeal shock wave lithotripsy. Staghorn calculi were excluded from this series. The over-all success rate (free of stones plus small asymptomatic residual fragments) was comparable with both modalities (percutaneous nephrostolithotomy 98 per cent and extracorporeal shock wave lithotripsy 95 per cent), although the presence of residual fragments was more common in kidneys treated with extracorporeal shock wave lithotripsy (24 versus 7 per cent). Patient morbidity as measured by temperature elevation, length of postoperative stay, pain and blood loss was significantly less (p less than 0.05) with extracorporeal shock wave lithotripsy than with percutaneous nephrostolithotomy.Re-treatment rates were similar with both procedures, and tended to increase in relation to increasing stone size and stone number. Post-treatment ancillary procedures (cystoscopy and stone manipulation, and percutaneous nephrostomy) were used more frequently with extracorporeal shock wave lithotripsy.Because of its efficacy and low morbidity, we conclude that extracorporeal shock wave lithotripsy is the treatment of choice for upper urinary tract calculi less than 2 cm. in diameter. However, percutaneous nephrostolithotomy will continue to have a primary role in the management of larger stones and cystine stones, and it will be used as a secondary procedure after unsuccessful extracorporeal shock wave lithotripsy treatments. In addition, because of the complimentary nature of these 2 new technologies certain complex stones, such as staghorn calculi, may be handled best by a combination of the 2 techniques. (J. Urol., 138: 485–490, 1987)