Factors Predicting Operating Room Time in Ureteroscopy and Ureterorenoscopy.

BACKGROUNDS/AIMS: Operation room (OR) time is of great value affecting surgical outcome, complications and the daily surgical program with financial implications. METHODS: We retrospectively evaluated 570 consecutive patients submitted to ureteroscopy or ureterorenoscopy for the treatment of ureteral or renal stones. Demographic parameters, patient's stones characteristics, type of ureteroscope, surgeon experience and surgical theater characteristics were analyzed. OR time was calculated from the initiation of anesthesia to patient extubation. Multivariate analysis was conducted using a linear regression test with multiple parameters to identify predictors of OR time. RESULTS: Eight factors were identified as significant. These include total stones volume, ureteroscope used, stone number, nurses experience, radio-opacity of the stone on kidney-ureter-bladder X-ray, main surgeon experience, operating room type, and having a nephrostomy tube prior to surgery. CONCLUSIONS: The surgical team experience and familiarity with endourological procedure, and the surgical room characteristics has a crucial impact on OR time and effectiveness.

"Stoneless" or Negative Ureteroscopy: A Reality in the Endourologic Routine or Avoidable Source of Frustration? Estimating the Risk Factors for a Negative Ureteroscopy.

INTRODUCTION: A "Negative" ureteroscopy (URS) is defined as a URS in which no stone is found during the procedure. It may occur when the stone has already been passed spontaneously or when it is located outside the collecting system. The aim of the study was to outline risk factors for Negative-URS. MATERIALS AND METHODS: We retrospectively analyzed the possible risk factors for Negative-URS from a database of 341 URS cases. In every case where presumptive ureteral stone was not found, a formal nephroscopy as well as a whole collecting system revision was completed. The Negative-URS group was compared with the non-Negative-URS group, in terms of patient and stone characteristics. RESULTS: The database of 341 URS cases included 448 different stone instances, of which 17 (3.8%) were negative and 431 (96.2%) were therapeutic. There was no statistical significant difference between the two groups concerning age, body mass index, stone location in the ureter, stone laterality, and whether the patient was prestented. The stepwise multiple logistic regression revealed three important risk factors, namely CT stone surface area (p < 0.0001), radiopacity of the stone at kidney, ureter, and bladder radiograph (KUB; p = 0.0004), and gender (p = 0.0011) with an area under the curve of 0.91. Women were found to have more possibilities to have a negative procedure by four- to sevenfold than men depending on the model. A nonradio-opaque stone at KUB is more likely to be correlated with a Negative-URS by 9.5- to 11-fold more than a radiopaque stone at KUB. For each increase of 1 U in CT stone surface area, there is an increase of 10%-12% to be non-negative. CONCLUSIONS: Female gender, a nonradio-opaque stone at KUB, and a smaller stone surface were statistically significantly different in the Negative-URS population.

Does Retrograde Treatment of Upper Urinary Tract Stones Necessitate Postoperative Upper Urinary Tract Drainage? Conclusions from More Than 500 Single Center Consecutive Cases.

BACKGROUND AND PURPOSE: Temporary drainage of the upper urinary tract after ureterorenoscopy for the treatment of urinary stones is almost a routine in endourologic practice. In these cases, a Double-J stent (DJS) is left for 7 or more days. In borderline cases, a ureteral catheter attached to the urethral catheter may be left for 24-48 hours. In some situations, tubeless approach is possible. The purpose of this study was to evaluate the necessity and immediate postoperative implications of upper tract drainage by comparing complications and symptoms at the immediate postoperative period in these three groups of patients. MATERIALS AND METHODS: A database of 516 consecutive patients who underwent ureterorenoscopy for ureteral and/or renal stones between October 2014 and September 2016 was retrospectively evaluated. The cohort was divided according to postoperative drainage type of the upper urinary tract. The data consisted of demographic parameters, stone location, number and burden, severity of preoperative obstruction, and postoperative complications. Symptoms at the immediate postoperative period, assessed by visual analog scale (VAS) score, frequency, and type of analgesics used, were evaluated and compared. Categorical dependent variables were evaluated using chi-square or Spearman's correlation tests, whereas continuous dependent variables were analyzed using Pearson correlation analysis. RESULTS: There were 196 (38%) tubeless, 214 (41%) UC, and 106 (21%) DJS cases. Patients who were drained with DJS at the end of the procedure were significantly with higher stone volume (p < 0.005), higher stone density (p < 0.005), and with more severe preoperative obstruction (p < 0.005). Postoperative complications (infection, stone-street, and acute renal failure), mean VAS score, or analgesics used were not different in the three subgroups. CONCLUSIONS: A tubeless approach is safe in properly selected cases. There is no difference in postoperative course compared with drained groups. Tubeless procedures may facilitate an outpatient approach for treatment of upper urinary tract stones.

History of Ureteral Stenting Negatively Affects the Outcomes of Extracorporeal Shockwave Lithotripsy. Results of a Matched-pair Analysis.

To evaluate the impact of ureteral stenting history to the outcomes of extracorporeal shockwave lithotripsy, we retrospectively analysed patients who underwent shockwave lithotripsy with Dornier Gemini lithotripter between September 2010 and August 2012. Forty seven patients (group A) who had a double J stent which was removed just before the procedure were matched-paired with another 47 patients (group B) who underwent shockwave lithotripsy having no stent history. The correlation between ureteral stenting history and stone-free rates was assessed. Stone-free rates were 68.1% and 87.2% for patients of group A and B, respectively (p=0.026). Postoperative complications were not different between groups. Multivariate analysis revealed that stone size (p=0.007), stone location (p=0.044) and history of ureteral stenting (p=0.046) were independent predictors for stone clearance after shockwave lithotripsy. Ureteral stents adversely affect shockwave lithotripsy outcome, even if they are removed before the procedure. Stenting history should divert treatment plan towards intracorporeal lithotripsy.

Do we really need kidneys-ureters-bladder radiography to predict stone radiopacity before treatment with shockwave lithotripsy? Development and internal validation of a novel predictive model based on computed tomography parameters.

PURPOSE: To produce and validate a predictive model based on CT parameters for calculating the probability of a stone to be visible on fluoroscopy of shockwave lithotripsy (SWL) and to compare its accuracy to that of kidneys-ureters-bladder (KUB) radiography. METHODS: We retrospectively analyzed 306 patients (sample group) who underwent an SWL between March 2011 and August 2012. A multivariate analysis of several parameters extracted from the preoperative CT scan was conducted to identify independent predictors for radiopacity on SWL fluoroscopy. The results were used for the creation of a predictive model. Internal validation was made on a group of 75 patients (validation group) treated from September 2012 until December 2012. Predictive accuracy of the model was evaluated by receiver operating characteristic (ROC) curve and calibration plot. The ROC curve was also used for comparing the predictive accuracy of the model to that of KUB radiography. RESULTS: From 306 evaluated stones, 238 (77.8%) were visible on fluoroscopy. Results of the multivariate analysis revealed that stone size (P<0.001), stone attenuation (P<0.001), location in the midureter (P<0.001), the distance between the stone and the anterior abdominal wall (P<0.001), and fat thickness of the anterior abdominal wall (P=0.001) were all independent predictors for stone radiopacity on fluoroscopy. A predictive model was produced based on the above parameters. The model demonstrated high calibration and areas under the curve of 0.923 and 0.965 in the sample and validation group, respectively, while its predictive performance was significantly higher (P<0.001) of that of KUB radiography (area under the curve=0.727). CONCLUSIONS: This novel model can estimate with high accuracy stone radiopacity on SWL fluoroscopy using parameters of CT scan and thus it can be used as an alternative to KUB radiography for treatment planning.

What happened to shockwave lithotripsy during the past 22 years? A single-center experience.

INTRODUCTION: From 1985 to August 2007 we have performed 15,324 shockwave lithotripsy (SWL) treatments using the Dornier HM3 lithotripter. We studied trends in the characteristics of treatments and patients. PATIENTS AND METHODS: Patient data were recorded in a computerized database. Changes in characteristics of patients and stones treated during this period were reviewed. RESULTS: A total of 15,324 treatments were performed on 10,734 patients. The following trends were observed: (1) Stone size: A significant increase in the proportion of patients treated for stones up to 10 mm in diameter, no change for stone size of 10 to 20 mm, and a decrease in stones larger than 20 mm in diameter. (2) Stone location: A significant increase in the proportion of patients treated for proximal and distal ureteral calculi, whereas a significant decrease in those with renal pelvic and staghorn stones. (3) Auxiliary procedures: A significant increase in the use of perioperative procedures (stents or ureteral catheters) ranging from 20% during the mid-1980s up to 60% in the year 2007. (4) Presenting symptoms: A significant increase in the percentage of patients referred with pain and a significant decrease in the percentage of patients referred with signs of infection. (5) Repeat SWL: A total of 13% of the patients required a second SWL for the same stone within 90 days of the first procedure. (6) Complication rate: This rate was relatively low, ranging from 1% to 6% per year. CONCLUSIONS: The evolvement of endourological procedures and techniques resulted in a decreased referral of large kidney stones for SWL. Advanced diagnostic modalities increased the diagnosis of renal colic in patients presenting with pain, and consequently their referral rate and timing for SWL treatment. The use of stents increased because of referral of patients with obstructing stones and infection or for prevention of posttreatment obstruction.

Fever after shockwave lithotripsy--risk factors and indications for prophylactic antimicrobial treatment.

PURPOSE: To identify risk factors for fever after shockwave lithotripsy (SWL) and suggest guidelines for prophylactic antimicrobial treatment. PATIENTS AND METHODS: Between 1985 and 2007, a total of 15,324 SWL procedures were performed in our institution using the Dornier HM3 lithotripter. Because stone analyses were not available in the majority of patients, management of stones larger than 2 cm in diameter were excluded from this analysis to minimize the ratio of struvite stones as a possible cause for postprocedural fever. In this analysis, 11,500 SWL treatments were included. Clinical parameters before, during, and after treatments were prospectively registered using a computerized database. Potential risk factors for fever after SWL were evaluated. RESULTS: Fever >38.0 degrees C developed in 161 (1.4%) patients. The risk factors for fever after SWL were: A positive urine culture (P < 0.05), an indwelling nephrostomy tube or stent during the procedure (P < 0.001), lithotripsy of kidney or upper ureteral stones (P < 0.05) and preoperative symptomatic urinary tract infection (UTI) (P < 0.05) or sepsis (P < 0.05). Lithotripsy of mid and lower ureteral stones, stone size, and the use of ureteral catheters during the procedures were not associated with increased risk of fever after SWL. CONCLUSIONS: Fever (>38.0 degrees C) develops in only 1.4% of the patients undergoing SWL. Therefore, prophylactic antibiotic treatment is not indicated in all patients. Selective prophylactic treatment is recommended in patients who present with UTI, kidney or upper ureteral stones, and those for whom a nephrostomy tube or stent is necessary.