[Antibiotic treatment of choice for urinary sepsis associated with ureteral lithiasis in Chile. Multicenter study]. / Tratamiento antibiótico de elección en sepsis urinaria asociada a litiasis ureteral en Chile. Estudio multicéntrico.

BACKGROUND: Inadequate antibiotic coverage in septic patients is associated with higher morbidity and mortality. This multicentric study reports antibiotic susceptibility in patients with ureterolithiasis-associated urosepsis, aiming to propose an optimal empirical therapy for this disease in the Chilean population. METHODS: The prospective cohort study included patients from 7 Chilean hospitals who presented with ureterolithiasis and met sepsis criteria. We analyzed demographic data, vital signs at admission, and microbiological and radiological exams. We used descriptive statistics for the analysis of collected data. RESULTS: Initially, the study included 119 patients; 52 met the inclusion criteria. 77% were female, with a mean age of 52. 100% of the cohort had a urine culture taken at admission, whereas 48,7% had blood cultures. Escherichia Coli was the most common microorganism (73%), followed by Proteus Mirabilis (9.6%) and Klebsiella Pneumoniae (3.9%). Only two patients presented gram-positive pathogens. 100% of gram-negative bacteria were sensible to amikacin. CONCLUSION: The microorganisms found in our cohort were similar to those in international reports. Since the highest level of susceptibility was for amikacin, we propose its use as empirical therapy for urosepsis associated with ureterolithiasis in Chile. It is always necessary to consider the potential nephrotoxic effects of amikacin. An association of beta-lactams and glycopeptides should be considered in patients with risk factors for enterococcal infections.

Treatment Response in Patients with Stones, and Low Urinary pH and Hypocitraturia Stratified by Body Mass Index.

PURPOSE: Obesity has been shown to be a risk factor for kidney stone formation. Obesity leads to insulin resistance which subsequently leads to low urinary pH. Low urinary pH is typically treated with potassium citrate. We determined if the response to potassium citrate for the treatment of low urinary pH and hypocitraturia varied when patients were stratified by body mass index. MATERIALS AND METHODS: We retrospectively reviewed the records of patients with urolithiasis and concomitant hypocitraturia and low urinary pH as unique abnormalities upon metabolic evaluation treated exclusively with potassium citrate. Based on body mass index the cohort was divided into the 4 groups of normal weight, overweight, obese and morbidly obese. Metabolic data were compared among the 4 groups at baseline and subsequent followup visits up to 2 years. We compared urinary pH and citrate in absolute values and the relative changes in these parameters from baseline. Similarly, we compared the rates of potassium citrate treatment failure. RESULTS: A total of 125 patients with hypocitraturia and low urinary pH were included in this study. Median patient age was 61 years, 80 patients were male and median body mass index was 30.4 kg/m(2). Patients with a higher body mass index tended to be younger (p=0.010), and had a lower urinary citrate but higher sodium, oxalate and uric acid levels. Urinary pH was similar across body mass index groups. pH values and their absolute changes from baseline were lower as body mass index increased (p ≤0.001). Similarly, we noted an association between increasing body mass index category and lower urinary citrate levels accompanied by a statistically significant trend indicating lower absolute changes in citrate with increasing body mass index (p ≤0.001). Potassium citrate dose was increased more frequently among the higher body mass index groups. CONCLUSIONS: Patients with a higher body mass index presented with a lower increase in citrate excretion and urinary pH levels after they were started on potassium citrate, and they needed more frequent adjustments to their therapy.

Does body mass index impact the outcomes of tubeless percutaneous nephrolithotomy?

OBJECTIVE: To evaluate whether body mass index (BMI) has an impact on the outcomes of tubeless percutaneous nephrolithotomy (PCNL). PATIENTS AND METHODS: We retrospectively reviewed patients who underwent tubeless PCNL at our institution from 2006 to 2011. Specifically, stone-free rates, complications, and hospital length of stay (LOS) were assessed. Patients were divided into four groups based on BMI: <25, 25-29.9, 30-34.9 and ≥35 kg/m(2) . Baseline characteristics and outcomes were compared between BMI groups. Multivariable logistic regressions were used to evaluate the independent contribution of BMI as a predictor of outcomes. RESULTS: We identified 268 patients who fulfilled study requirements. The overall stone-free and complication rates were 52.5% and 19.0%, respectively. Minor and severe complication comprised 10.4% and 8.6%, respectively. Univariate and multivariable analyses showed no association between BMI and stone-free or complication rates. However, patients with a normal BMI had significantly higher transfusion rates (P = 0.005), and were significantly more likely to have a prolonged LOS (≥2 days), when compared with an overweight BMI (P = 0.032) CONCLUSIONS: BMI did not impact the stone-free, or complication rates of tubeless PCNL. Normal BMI was found to be a risk factor for prolonged LOS, which may be due to an increase in clinically significant bleeding in this patient population. Tubeless PCNL appears to be a safe and effective procedure for the treatment of complex renal calculi, independent of BMI.

Assessment of a modified acoustic lens for electromagnetic shock wave lithotripters in a swine model.

PURPOSE: The acoustic lens of the Modularis electromagnetic shock wave lithotripter (Siemens, Malvern, Pennsylvania) was modified to produce a pressure waveform and focal zone more closely resembling that of the original HM3 device (Dornier Medtech, Wessling, Germany). We assessed the newly designed acoustic lens in vivo in an animal model. MATERIALS AND METHODS: Stone fragmentation and tissue injury produced by the original and modified lenses of the Modularis lithotripter were evaluated in a swine model under equivalent acoustic pulse energy (about 45 mJ) at 1 Hz pulse repetition frequency. Stone fragmentation was determined by the weight percent of stone fragments less than 2 mm. To assess tissue injury, shock wave treated kidneys were perfused, dehydrated, cast in paraffin wax and sectioned. Digital images were captured every 120 µm and processed to determine functional renal volume damage. RESULTS: After 500 shocks, the mean ± SD stone fragmentation efficiency produced by the original and modified lenses was 48% ± 12% and 52% ± 17%, respectively (p = 0.60). However, after 2,000 shocks, the modified lens showed significantly improved stone fragmentation compared to the original lens (mean 86% ± 10% vs 72% ± 12%, p = 0.02). Tissue injury caused by the original and modified lenses was minimal at a mean of 0.57% ± 0.44% and 0.25% ± 0.25%, respectively (p = 0.27). CONCLUSIONS: With lens modification the Modularis lithotripter demonstrates significantly improved stone fragmentation with minimal tissue injury at a clinically relevant acoustic pulse energy. This new lens design could potentially be retrofitted to existing lithotripters, improving the effectiveness of electromagnetic lithotripters.

Obesity triples the radiation dose of stone protocol computerized tomography.

PURPOSE: Patients with recurrent nephrolithiasis are often evaluated and followed with computerized tomography. Obesity is a risk factor for nephrolithiasis. We evaluated the radiation dose of computerized tomography in obese and nonobese adults. MATERIALS AND METHODS: We scanned a validated, anthropomorphic male phantom according to our institutional renal stone evaluation protocol. The obese model consisted of the phantom wrapped in 2 Custom Fat Layers (CIRS, Norfolk, Virginia), which have been verified to have the same radiographic tissue density as fat. High sensitivity metal oxide semiconductor field effect transistor dosimeters were placed at 20 organ locations in the phantoms to measure organ specific radiation doses. The nonobese and obese models have an approximate body mass index of 24 and 30 kg/m(2), respectively. Three runs of renal stone protocol computerized tomography were performed on each phantom under automatic tube current modulation. Organ specific absorbed doses were measured and effective doses were calculated. RESULTS: The bone marrow of each model received the highest dose and the skin received the second highest dose. The mean ± SD effective dose for the nonobese and obese models was 3.04 ± 0.34 and 10.22 ± 0.50 mSv, respectively (p <0.0001). CONCLUSIONS: The effective dose of stone protocol computerized tomography in obese patients is more than threefold higher than the dose in nonobese patients using automatic tube current modulation. The implication of this finding extends beyond the urological stone population and adds to our understanding of radiation exposure from medical imaging.

Radiation exposure in urology: a genitourinary catalogue for diagnostic imaging.

PURPOSE: Computerized tomography use increased exponentially in the last 3 decades, and it is commonly used to evaluate many urological conditions. Ionizing radiation exposure from medical imaging is linked to the risk of malignancy. We measured the organ and calculated effective doses of different studies to determine whether the dose-length product method is an accurate estimation of radiation exposure. MATERIALS AND METHODS: An anthropomorphic male phantom validated for human organ dosimetry measurements was used to determine radiation doses. High sensitivity metal oxide semiconductor field effect transistor dosimeters were placed at 20 organ locations to measure specific organ doses. For each study the phantom was scanned 3 times using our institutional protocols. Organ doses were measured and effective doses were calculated on dosimetry. Effective doses measured by a metal oxide semiconductor field effect transistor dosimeter were compared to calculated effective doses derived from the dose-length product. RESULTS: The mean±SD effective dose on dosimetry for stone protocol, chest and abdominopelvic computerized tomography, computerized tomography urogram and renal cell carcinoma protocol computerized tomography was 3.04±0.34, 4.34±0.27, 5.19±0.64, 9.73±0.71 and 11.42±0.24 mSv, respectively. The calculated effective dose for these studies Was 3.33, 2.92, 5.84, 9.64 and 10.06 mSv, respectively (p=0.8478). CONCLUSIONS: The effective dose varies considerable for different urological computerized tomography studies. Renal stone protocol computerized tomography shows the lowest dose, and computerized tomography urogram and the renal cell carcinoma protocol accumulate the highest effective doses. The calculated effective dose derived from the dose-length product is a reasonable estimate of patient radiation exposure.

Radiological differential diagnosis and management of retroperitoneal hematomas posterior to radical inguinal orchiectomies. A case report.

Introduction: Retroperitoneal hematomas are rare complications of radical inguinal orchiectomy. This case report discusses their radiological differential diagnosis and management. Case presentation: A radical inguinal orchiectomy was performed on a 27-year-old patient. After discharge, he referred back pain. Computed tomography showed a retroperitoneal hematoma. A conservative approach was decided. Discussion: Traditionally, retroperitoneal hematomas have been considered possible radiologic pitfalls, which has therapeutical implications. This pitfall seems less likely in contemporary clinical practice.A conservative approach is preferred in stable patients, whereas active management should be offered to unstable patients. Conclusion: Future studies are necessary to offer evidence-based therapeutical options.

Intrarenal temperature measurement associated with holmium laser intracorporeal lithotripsy in an ex vivo model.

INTRODUCTION: The aim of this article was to quantify the effect of the use of holmium laser during intracorporeal lithotripsy in an ex vivo model. MATERIAL AND METHODS: A simulated model for laser nephro-lithotripsy was designed. Two ex vivo porcine kidneys were used. Electronic thermometer electrodes were inserted on the upper calyx. Intracorporeal lithotripsy was simulated with a holmium laser. Intrarenal temperature was recorded both at the beginning and after one minute of laser use with delta temperature (DT) defined as the difference between them. Measurements were made at different irrigation heights (30, 40, and 50 cm H2O), frequency (Hz), and laser energy (J) in addition to the presence or absence of the access sheath. Analysis of factors associated with temperature change was performed. RESULTS: Thirty-eight observations were recorded. The measurement without the use of access sheath showed an average DT of 4.9, 5.1, and 6.5°C for 5, 10, and 15 Hz, respectively; however, with a sheath, DTs were 0.2, 0.5, and 1.5°C. In terms of energy, mean DTs of 4.3, 6.1, 5.2, and 13.9°C for 0.5, 0.8, 1.0, and 1.5 J were recorded; in contrast, with a sheath, averages of 0.4, 0.5, 0.5, and 3.8°C, respectively were noted. In the adjusted model, energy, frequency, and use of sheath and water height were significant. CONCLUSIONS: The configuration of the laser significantly modifies the intrarenal temperature and height of the bladder irrigation. The use of an access sheath provides lower intrarenal temperatures regardless of laser configuration and water height.

Endoscopic Treatment of Fibroepithelial Polyp of the Ureter: Case Report.

Background: Fibroepithelial polyp of the ureter is a very rare benign tumor of the urinary tract that can present complications as urinary tract infection, hematuria, or urinary retention. Its incidence has increased in recent years. Its recognition and proper management are important to avoid invasive surgeries. Case Presentation: We present the case of a 24-year-old Latin pregnant woman with gross hematuria, right flank pain, and a bladder tumor as seen on a pelvic ultrasonography. Cystoscopy and MRI showed a right ureteral tumor that protruded through the ureteral meatus. Endoscopic resection using a holmium:YAG laser was performed during the second trimester of pregnancy. A ureteral tumor of 6.5 cm was completely resected. Histopathology showed morphological findings compatible with a fibroepithelial ureteral polyp. The postoperative evolution was satisfactory with no complications or recurrences to date. Conclusion: Fibroepithelial polyp of the ureter is a benign tumor that can be present in any of the ureter's segments. It usually affects people between 20 and 40 years. Endoscopic resection with holmium laser has become the preferred surgical treatment during the last time. It is associated with the advantages of a minimal invasive technique and a short period of convalescence.

Early ureteroscopic treatment in patients with urosepsis associated with ureteral calculi is a safe approach. A pilot study.

INTRODUCTION: Emergency drainage of the urinary tract is the first necessary approach in patients with urosepsis secondary to obstructive ureteral calculi. The appropriate waiting time before definitive treatment has not been determined. We hypothesized that early ureteroscopic treatment after the patient has been stabilized is as safe as deferred treatment. MATERIAL AND METHODS: A pilot study was developed between November 2013 and September 2017. Patients with urosepsis associated with ureteral calculi were included. All the patients were initially decompressed with a ureteral stent. Patients were randomized to early ureteroscopic treatment (EUT), who received definitive treatment during the initial hospitalization, or deferred ureteroscopic treatment (DUT), that received definitive treatment in a second hospitalization. The stone location and size, sex distribution, age, APACHE II score, length of hospital stay, days with ureteral catheter and complications were registered. Statistical analysis was performed using Stata 12.0. RESULTS: A total of 13 patients were included in the EUT group and 13 in the DUT group. No differences in sex distribution, stone location, APACHE II score, age, stone size and time between admission and urinary drainage were found. Total length of hospital stay and complications were also similar between both groups. A statistically significant difference was found in terms of duration of antibiotic treatment (p = 0.04) and total days with double J catheter (p = 0.0009). CONCLUSIONS: EUT for ureteral stone is as safe as DUT in patients admitted with urosepsis secondary to ureterolithiasis. EUT is associated with a shorter period of ureteral stent and it is not associated with an increase in complications.

Tratamiento antibiótico de elección en sepsis urinaria asociada a litiasis ureteral en Chile. Estudio multicéntrico

Introducción: El uso de un esquema antibiótico inadecuado en sepsis aumenta significativamente la morbimortalidad. Este estudio presenta un reporte multicéntrico de susceptibilidad antibiótica en urosepsis asociada a ureterolitiasis, buscando proponer un esquema empírico óptimo para el medio nacional. Métodos: Se realizó un estudio observacional prospectivo en 7 hospitales de 4 regiones del país. Se incluyeron pacientes con criterios de sepsis asociada a ureterolitiasis confirmada radiológicamente. Se registraron sus datos demográficos, signos vitales y laboratorio de ingreso, así como sus estudios microbiológicos y radiológicos, realizándose estadísticas descriptivas de los datos obtenidos. Resultados: Se ingresaron 119 pacientes, de los cuales 52 cumplieron criterios de inclusión. 77% eran mujeres, con una edad promedio de 52 años. Se tomaron hemocultivos en el 48,7% de los casos y urocultivos en el 100%. El microorganismo más común fue Escherichia coli (73%), seguido por Proteus mirabilis (9,6%) y Klebsiella pneumoniae (3,9%). Hubo dos casos de bacterias gram positivas. El 100% de las bacterias gram negativas fueron sensibles a amikacina. Conclusión: Los microorganismos encontrados en nuestra cohorte fueron similares a los de los estudios internacionales. Dado que el mayor nivel de susceptibilidad fue para amikacina, proponemos su uso como terapia empírica para la urosepsis asociada a ureterolitiasis en Chile. Siempre es necesario considerar los posibles efectos ne-frotóxicos de la amikacina. Se debe considerar una asociación de betalactámicos y glicopéptidos en pacientes con factores de riesgo de infecciones enterocócicas.

Background: Inadequate antibiotic coverage in septic patients is associated with higher morbidity and mortality. This multicentric study reports antibiotic susceptibility in patients with ureterolithiasis-associated urosepsis, aiming to propose an optimal empirical therapy for this disease in the Chilean population. Methods: The prospective cohort study included patients from 7 Chilean hospitals who presented with ureterolithiasis and met sepsis criteria. We analyzed demographic data, vital signs at admission, and microbiological and radiological exams. We used descriptive statistics for the analysis of collected data. Results: Initially, the study included 119 patients; 52 met the inclusion criteria. 77% were female, with a mean age of 52. 100% of the cohort had a urine culture taken at admission, whereas 48,7% had blood cultures. Escherichia Coli was the most common microorganism (73%), followed by Proteus Mirabilis (9.6%) and Klebsiella Pneumoniae (3.9%). Only two patients presented gram-positive pathogens. 100% of gram-negative bacteria were sensible to amikacin. Conclusion: The microorganisms found in our cohort were similar to those in international reports. Since the highest level of susceptibility was for amikacin, we propose its use as empirical therapy for urosepsis associated with ureterolithiasis in Chile. It is always necessary to consider the potential nephrotoxic effects of amikacin. An association of beta-lactams and glycopeptides should be considered in patients with risk factors for enterococcal infections.

Is a ureteral stent required after use of ureteral access sheath in presented patients who undergo flexible ureteroscopy?

INTRODUCTION: Use of a ureteral access sheath (UAS) within flexible ureteroscopy (fURS) for the management of kidney and ureteral stones has shown improvements in its effectiveness, but it is also associated with increased risk of ureteral injury. Use of ureteral stent (US) after fURS is recommended by some authors, because of its role in reducing postoperative pain and preventing complications. Our objective is to determine if postoperative stenting is necessary in pre-stented patients that underwent fURS using UAS. MATERIAL AND METHODS: A retrospective history review of patients who underwent fURS using UAS at our hospital between July 1st 2013 and May 31st 2016 was performed. Only pre-stented patients were included. All procedures were performed using the same UAS (Boston Navigator TM., 11-13 Fr.). Patients were separated according to the use or not of postoperative US. The same US (26 cm 6 Fr percuflex, Boston Scienfic) was used for all stented patients. Clinical parameters, stone demographics, operative time and postoperative events were analyzed. RESULTS: Seventy patients met the inclusion criteria. Mean stone size was 8.5 mm (SD 7.06), 68.49% were located in the renal pelvis and 31.51% were in the proximal ureter. Reasons of preoperative stenting were: 14 (19.18%) ureteral stricture, 17 (23.29%) urosepsis, 29 (39.73%) residual stones after a first intervention (stage procedure) and 13 (17.8%) unsuccessful extracorporeal shockwave lithotripsy. Mean operative time was 88 minutes (SD 37.20); 32 patients (45.71%) were stented and 38 (54.28%) were not. There were no significant differences in operative time (p = 0.85) or postoperative outcomes (p = 1). CONCLUSIONS: A postoperative ureteral stent is not necessary after fURS using UAS in pre-stented patients.

Subcapsular Renal-Infected Hematoma After Retrograde Intrarenal Surgery: A Rare but Serious Complication.

We report a case of a 53-year-old woman affected by a left kidney stone and persistent positive urinary culture treated by retrograde intrarenal surgery. During postoperative day 1, she developed a sudden back pain associated with a decrease in hemoglobin. CT scan showed a subcapsular hematoma giving the impression of partial compression of kidney and upper urinary tract. For that reason, in the first instance, a Double-J ureteral stent was installed. Unfortunately, an open surgical drainage was necessary because a secondary infection of the hematoma was evident during the following days.

Validation of a high-fidelity model in ureteroscopy incorporating hand motion analysis.

PURPOSE: To establish the construct validity of a semirigid ureteroscopy in a high-fidelity simulation model, incorporating hand motion analysis as a paramount part of evaluation. METHODS: Participants were divided into 3 groups: group 1 (9 junior residents, without experience in ureteroscopy), group II (9 senior residents, with variable experience in ureteroscopy) and group III (2 experts in endourologist); each group performed a single practice session in the high-fidelity bench model, which was previously prepared with small urinary stone phantom in the mid-ureter. Assessment was done using motion tracking device (ICSAD). Procedures were recorded in external vision and endoscopic vision and scored by two blinded evaluators using a Global Rating Scale and ureteral checklist (OSATS). RESULTS: Significant differences were observed in time taken, path length, numbers of movements, Global Rating Scale and checklist in favor of the experts group. Subanalysis demonstrated no relevant differences between groups II and III in general dexterity parameters except for the non-dominant hand, where experts showed a significant less number of movement (34 vs 221; p = 0.03) and path length (12.1 vs 45.1; p = 0.03). The interrater reliability of the GRS was excellent (0.81; p < 0.001), while for checklist ICC was moderate (0.45; p = 0.03). CONCLUSIONS: The incorporation of ICSAD into the construct validity of this ureteroscopy model complements traditional methods used to achieve construct validity (OSATS). To our knowledge, this study is the first report using motion analysis as a tool for performance evaluation in a simulated endourological procedure.

Does the nephrostomy tract length impact the outcomes of percutaneous nephrolithotomy (PNL)?

PURPOSE: Different factors can determine the outcomes of percutaneous nephrolithotomy (PNL). We analyzed the effect of tract length (TL) on outcomes after PNL. METHODS: We performed a retrospective review of patients undergoing PNL between 2006 and 2011. Patients with preoperative computed tomography (CT), one percutaneous access tract and follow-up imaging within 3 months were included. TL was defined as distance between the skin to the calyx of puncture as measured on preoperative CT. Measurements were independently performed by two urologists and the average was used for analysis. Stone-free rate (SFR) was defined as zero fragments on follow-up imaging. Factors independently associated with the likelihood of being stone-free after PNL were determined using multivariable analysis adjusted for TL, location of access, the presence of incomplete or complete staghorn calculi and type of follow-up imaging. Complications (Clavien score) were independently assessed. RESULTS: A total of 222 patients were included. Median stone burden and body mass index (BMI) was 239.4 mm(2) and 30.5 [interquartile range (IQR): 25.7-36.2]. The median TL was 85.0 mm (IQR: 70.3-100.0) and highly correlated with BMI (ρ = 0.66, p < 0.001). A total of 101 patients (45.5 %) were stone-free. TL was not associated with SFR (p = 0.53). Clavien 1 and 2 complications occurred in 38 (17 %) while Clavien 3 and 4 complications occurred in 17 (8 %) patients. Multivariable analysis revealed no association between complications and TL even when adjusted for gender. CONCLUSIONS: Percutaneous TL is not associated with outcomes of PNL. PNL is a safe and effective treatment for stones in patients with differing body habitus.

Digital tomosynthesis: a new technique for imaging nephrolithiasis. Specific organ doses and effective doses compared with renal stone protocol noncontrast computed tomography.

OBJECTIVE: To determine organ-specific doses (ODs) and effective dose (ED) for digital tomosynthesis (DT) and compare it with our institutional renal stone protocol noncontrast computed tomography (NCCT). METHODS: A validated anthropomorphic male phantom was placed supine on a digital GE Definium 8000 radiological scanner. Thermoluminescent dosimeters were placed in 256 locations and used to measure OD. A routine DT study was performed consisting of 2 scout images and 1 tomographic sweep in a 14.2-degree arc over the phantom. Software is used to recreate a series of coronal images from the sweep. ODs were determined as the sum of the doses for the study. Equivalent doses were calculated by multiplying OD with the appropriate tissue weighting factor. ED is the summation of the equivalent doses. OD and ED were determined in a similar fashion (using dosimeters) for a renal stone protocol NCCT and doses were compared. RESULTS: ODs for DT are significantly lower compared with NCCT. The ED for NCCT is 3.04 ± 0.34 mSv. The calculated ED for DT is 0.87 ± 0.15 mSv (2 scouts at 0.17 mSv and 0.14 mSv and 1 sweep at 0.56 mSv), P <.0001. CONCLUSION: DT exposes patients to substantially less radiation than NCCT. This is particularly true for radiation-sensitive organs. Further studies are needed to compare the sensitivity and specificity of DT as compared with NCCT. However, its low overall radiation dose makes it an ideal study for the follow-up of recurrent stone formers in the office setting.

Effect of supine vs prone position on outcomes of percutaneous nephrolithotomy in staghorn calculi: results from the Clinical Research Office of the Endourology Society Study.

OBJECTIVE: To analyze the effect of patient positioning on outcomes of percutaneous nephrolithotomy (PNL) among patients with staghorn stones. The choice of optimal position for these patients undergoing PNL remains challenging. No previous studies exclusively addressing this point have been performed. METHODS: From November 2007 to December 2009, prospective data were collected by the Clinical Research Office of the Endourological Society. We included all patients with staghorn stones. Patients were divided on the basis of the position used during PNL (prone/supine). Patient characteristics, stone burden, operative details, and outcomes were compared. Multivariate analysis was performed to evaluate the relationship between patient position and stone-free rate and complication rate adjusting for number of access puncture sites. RESULTS: A total of 1079 PNLs were performed in prone and 232 in supine positions. There were no differences in comorbidities or preoperative stone burden. A higher percentage of patients in the prone position had access through the upper pole (P <.001). Surgical time was shorter (P <.001) and stone-free rate was higher (P <.001) for patients in the prone position. There were no differences in complication rates. In multivariate analysis, patients in prone position had a higher stone-free rates (P = .0013) after adjusting for the method used for determining stone-free status and number of renal access. CONCLUSION: Higher stone-free rates are achieved in the prone position during PNL for patients with staghorn calculi. Complication rates were similar for both positions.

Radiation exposure in the follow-up of patients with urolithiasis comparing digital tomosynthesis, non-contrast CT, standard KUB, and IVU.

OBJECTIVE: To compare the effective doses (EDs) associated with imaging modalities for follow-up of patients with urolithiasis, including stone protocol non-contrast computed tomography (NCCT), kidney, ureter, and bladder radiograph (KUB), intravenous urogram (IVU), and digital tomosynthesis (DT). METHODS: A validated Monte-Carlo simulation-based software PCXMC 2.0 (STUK) designed for estimation of patient dose from medical X-ray exposures was used to determine the ED for KUB, IVU (KUB scout plus three tomographic images), and DT (two scouts and one tomographic sweep). Simulations were performed using a two-dimensional stationary field onto the corresponding body area of the built-in digital phantom, with actual kVp, mAs, and geometrical parameters of the protocols. The ED for NCCT was determined using an anthropomorphic male phantom that was placed prone on a 64-slice GE Healthcare volume computed tomography (VCT) scanner. High-sensitivity metal oxide semiconductor field effect transistors dosimeters were placed at 20 organ locations and used to measure organ radiation doses. RESULTS: The ED for a stone protocol NCCT was 3.04±0.34 mSv. The ED for a KUB was 0.63 and 1.1 mSv for the additional tomographic film. The total ED for IVU was 3.93 mSv. The ED for DT performed with two scouts and one sweep (14.2°) was 0.83 mSv. CONCLUSIONS: Among the different imaging modalities for follow-up of patients with urolithiasis, DT was associated with the least radiation exposure (0.83 mSv). This ED corresponds to a fifth of NCCT or IVU studies. Further studies are needed to demonstrate the sensitivity and specificity of DT for the follow-up of nephrolithiasis patients.

Increasing dwell time of mitomycin C in the upper tract with a reverse thermosensitive polymer.

UNLABELLED: Abstract Background and Purpose: Topical chemotherapy for urothelial cancer is dependent on adequate contact time of the chemotherapeutic agent with the urothelium. To date, there has not been a reliable method of maintaining this contact for renal or ureteral urothelial carcinoma. We evaluated the safety and feasibility of using a reverse thermosensitive polymer to improve dwell times of mitomycin C (MMC) in the upper tract. MATERIALS AND METHODS: Using a porcine model, four animals were treated ureteroscopically with both upper urinary tracts receiving MMC mixed with iodinated contrast. One additional animal received MMC percutaneously. The treatment side had ureteral outflow blocked with a reverse thermosensitive polymer plug. MMC dwell time was monitored fluoroscopically and intrarenal pressures measured. Two animals were euthanized immediately, and three animals were euthanized 5 days afterward. RESULTS: In control kidneys, drainage occurred at a mean of 5.3±0.58 minutes. Intrarenal pressures stayed fairly stable: 9.7±14.0 cm H20. In treatment kidneys, dwell time was extended to 60 minutes, when the polymer was washed out. Intrarenal pressures in the treatment kidneys peaked at 75.0±14.7 cm H20 and reached steady state at 60 cm H20. Pressures normalized after washout of the polymer with cool saline. Average washout time was 11.8±9.6 minutes. No histopathologic differences were seen between the control and treatment kidneys, or with immediate compared with delayed euthanasia. CONCLUSIONS: A reverse thermosensitive polymer can retain MMC in the upper urinary tract and appears to be safe from our examination of intrarenal pressures and histopathology. This technique may improve the efficacy of topical chemotherapy in the management of upper tract urothelial carcinoma.