Impact of retrograde flexible ureteroscopy and intracorporeal lithotripsy on kidney functional outcomes

ABSTRACT Objective: The aim of the study was to evaluate renal function and to identify factors associated with renal function deterioration after retrograde intrarenal surgery (RIRS) for kidney stones. Materials and Methods: We retrospectively analyzed patients with renal stones treated by RIRS between January 2010 and June 2013 at a single institute. We used the National Kidney Foundation classification of chronic kidney disease (CKD) to classify Glomerular Filtration Rate (GFR) in 5 groups. The baseline creatinine level was systematically pre-operatively and post-operatively evaluated. All patients had a creatinine blood measurement in June 2013. A change toward a less or a more favorable GFR group following RIRS was considered significant. Results: We included 163 patients. There were 86 males (52.8%) and 77 females (47.3%) with a mean age of 52.8±17 years. After a mean follow-up of 15.5±11.5 months, median GFR was not significantly changed from 84.3±26.2 to 84.9±24.5 mL/min (p=0.675). Significant renal function deterioration occurred in 8 cases (4.9%) and significant renal function amelioration occurred in 23 cases (14.1%). In univariate analysis, multiple procedures (p=0.023; HR: 5.4) and preoperative CKD (p=0.011; HR: 6.8) were associated with decreased renal function. In multivariate analysis these factors did not remain as predictive factors. Conclusion: Stone management with RIRS seems to have favorable outcomes on kidney function; however, special attention should be given to patients with multiple procedures and preoperative chronic kidney disease.

Value of CT angiography in reducing the risk of hemorrhage associated with mini-percutaneous nephrolithotomy

ABSTRACTPurpose:To evaluate the clinical value of computed tomography angiography (CTA) in reducing the risk of hemorrhage associated with mini-percutaneous nephrolithotomy (PCNL).Materials and Methods:A total of 158 patients with renal or ureter stones who had undergone mini-percutaneous nephrolithotomy were retrospectively enrolled into this study from May of 2011 to April of 2014. Group 1 (65 patients) underwent computed tomography angiography, and Group 2 (93 patients) underwent non-contrast CT. The clinical characteristics of the patients and hemorrhagic complications were recorded. The hematologic complications (transfusion rate, and preoperative and postoperative hemoglobin values) were assessed.Results:There were no statistically significant differences in age, body mass index(BMI), stone diameter, operative time, stone-free rate, and hospital stay between the 2 groups. In group 2, 1 patient (1.1%) developed a renal arteriovenous fistula and was treated with embolus therapy. In addition, Group 2 showed significantly drop in hemoglobin (3.6 g/dL vs. 2.4 g/dL, respectively; P <0.001) and more transfusions (9.7% vs. 1.5%, respectively; P <0.05) compared with Group 1.Conclusion:The study showed that patients who underwent computed tomography angiography prior to percutaneous nephrolithotomy had lower drop of hemoglobin and needed less transfusions. These findings may suggest that the use of computed tomography angiography may reduce the risk of bleeding during percutaneous nephrolithotomy.

Flexible Ureteroscopic Management of Horseshoe Kidney Renal Calculi

ABSTRACTPurpose:To evaluate the clinical efficacy of flexible ureteroscope (F-URS) combined with holmium laser lithotripter in treating renal calculi in horseshoe kidney.Materials and Methods:From November 2010 to December 2013, the medical history and charts of sixteen patients (mean age 42.9±11.6 years, range 26-66 years), including 13 males and 3 females were analyzed retrospectively. Mean stone burden was 29±8 mm (range 17-42 mm2). Mean stone digitized surface area (DSA) was 321±94 mm2 (range 180-538 mm2). Under spinal anesthesia in a modified lithotomy position with the head down, rigid ureteroscope was placed firstly into the ureter to reach the level of the pelvis, a zebra guide wire was inserted and following the removal of the rigid ureteroscope, an ureteral access sheath was positioned along the guide wire, then passed the URF P-5 flexible ureteroscope into the renal cavities over the guidewire. After locating the stones, holmium laser lithotripsy was performed.Results:The average operative time was 92±16 minutes (range 74-127 min.). No major complications were encountered. Ten patients obtained stone-free status with one session, four obtained stone-free status after two sessions. Single session stone-free rate was 62.5%, overall stone-free rate was 87.5%. Two patients have small residual stones in the lower pole.Conclusions:F-URS combined with holmium laser lithotripter and nitinol basket, is safe and effective in dealing with moderate stone diameter (<30 mm) in HSKs with high clearance rates and low complication rates.

Is quantitative diffusion-weighted MRI a valuable technique for the detection of changes in kidneys after extracorporeal shock wave lithotripsy?

Objective The aim of this study was to evaluate the capability and the reliability of diffusion-weighted imaging (DWI) in the changes of kidneys occurring after extracorporeal shock wave lithotripsy (ESWL) treatment for renal stones. Materials and Methods A total of 32 patients who underwent ESWL treatment for renal stone disease between June and December 2011 were enrolled in this prospective study. Color Doppler ultrasonography (CDUS) and DWI were performed before and within 24 hours after ESWL. DWI was obtained with b factors of 0, 500 and 1000 s/mm2 at 1.5 T MRI. Each of Resistive index (RI) and ADC values were calculated from the three regions of renal upper, middle and lower zones for both of the affected and contralateral kidneys. Paired sample t test was used for statistical analyses. Results After ESWL, the treated kidneys had statistically significant lower ADC values in all different regions compared with previous renal images. The best discriminative parameter was signal intensity with a b value of 1000 s/mm2. The changes of DWI after ESWL were noteworthy in the middle of the treated kidney (p<0.01). There were no significant difference between RI values in all regions of treated and contralateral kidneys before and after treatment with ESWL (p>0.05). Conclusion DWI is a valuable technique enables the detection of changes in DWI after ESWL treatment that may provide useful information in prediction of renal damage by shock waves, even CDUS is normal. .

Steinstrasse predictive factors and outcomes after extracorporeal shockwave lithotripsy

PURPOSE: Urinary stone disease is a common medical problem. Extracorporeal shockwave lithotripsy (SWL) has been applied with high success and low complication rates. Steinstrasse (SS) is a possible complication after SWL. The aim of the present study was to prospectively evaluate the factors and outcomes associated with SS after SWL. MATERIALS AND METHODS: We have prospectively evaluated 265 SWL sessions (2005-2009). Two lithotriptors were used randomly: Siemens Lithostar and Dornier Compact S. All patients had imaging exams after 30 and 90 days or according to symptoms. RESULTS: SS was observed in 14 (5.3 percent) out of 265 SWL procedures (n = 175 patients, 51.5 percent women/48.5 percent men, mean ± SD age = 46.3 ± 15.5 years). SS was more common after SWL for pelviureteral calculi rather than caliceal stones (p = 0.036). There was a trend toward more occurrences of SS after SWL for larger stone area (> 200 mm², p = 0.072). Preoperative ureteral stent didn't prevent SS. SWL machine, intensity, number of pulses and frequency were not associated with SS formation. Post-SWL pain, fever and gravel elimination were factors associated with SS (p = 0.021; p = 0.011; p = 0.078). When SS occurred, treatment modalities included Medical Expulsive Therapy (MET), ureteroscopy and SWL. CONCLUSIONS: Steinstrasse is an uncommon event after SWL and seems to occur more frequently with larger pelviureteral stones. Impaction of stones is more frequent in the middle ureter. All patients should be followed after SWL, but SS should be specially suspected if there is macroscopic gravel elimination, flank pain and/or fever. When SS occurs, treatment should be promptly introduced, including medical expulsive therapy, surgical approach or SWL in selected cases. Further prospective studies are awaited to evaluated preventive measures for SS occurrence.

Extracorporeal shock wave lithotripsy in the treatment of renal pelvicalyceal stones in morbidly obese patients

INTRODUCTION: Management of urolithiasis in morbidly obese patients is usually associated with higher morbidity and mortality compared to non-obese patients. In morbidly obese patients, since the kidney and stone are at a considerable distance from the skin (compared to non-obese patients) difficulty may be found in positioning the patient so that the stone is situated at the focal point of the lithotripter. OBJECTIVE: To evaluate the outcomes and cost-efficiency of extracorporeal shock wave lithotripsy (ESWL) in the treatment of renal pelvicalyceal stones sized between 6 and 20 mm in morbidly obese patients. MATERIALS AND METHODS: Using various aids, such as mobile overtable module, extended shock pathway and abdominal compression 37 patients with body mass index more than 40 kg/m2 were treated using the Siemens Lithostar-plus third generation lithotripter. The size of renal pelvicalyceal stones was between 6 and 20 mm. Treatment costs for shock wave lithotripsy were calculated. RESULTS: The overall stone free rate at 3 months of 73 percent was achieved. The mean number of treatments per patient was 2.1. The post-lithotripsy secondary procedures rate was 5.4 percent. No complications, such as subcapsular haematoma or acute pyelonephritis were recorded. The most effective (87 percent success rate) and cost-efficient treatment was in the patients with pelvic stones. The treatment of the patients with low caliceal stones was effective in 60 percent only. The cost of the treatment of the patients with low calyceal stones was in 1.8 times higher than in the patients with pelvic stones. CONCLUSION: We conclude that ESWL with the Siemens Lithostar-plus is the most effective and cost-efficient in morbidly obese patients with pelvic stones sized between 6 and 20 mm. 87 percent success rate was achieved. The increased distance from the skin surface to the stone in those patients does not decrease the success rate provided the stone is positioned in the focal point or within 3 cm of it on the extended shock pathway. ESWL should not be considered as the first line of treatment in the morbidly obese patients with low caliceal stones where the stone was positioned more than 1 cm from the focal point on the extended shock pathway.

Nefrolitiasis: aspectos clínicos y epidemiológicos / Nephrolithiasis: epidemiologic and clinical features

El presente estudio tuvo como objetivo conocer la incidencia y características de la nefrolitiasis en un medio hospitalario. Durante abril de 1985 y enero de 1989 se atendieron en los consultorios externos del Hospital Cayetano Heredia 110,610 pacientes, de los cuales 245 correspondieron a pacientes con diagnóstico de nefrolitiasis. Se presentan las características epidemiológicas, clínicas y evolutivas de estos pacientes. Se encuentrán una incidencia de 2.2 por mil, mayor a las reportadas en la literatura. No hubo diferencia entre sexos. El 77.2 por ciento de los pacientes estan comprendidos entre los grupos productivos de la población lo cual produce un impacto socioeconómico importante. El 18 por ciento de los pacientes tiene algún familiar de primer grado con nefrolitiasis. El tiempo de enfermedad promedio fue 2.2 años, el 10 por ciento de los pacientes fueron asintomáticos, los síntomas más frecuentes fueron el cólico renal y la hematuria macroscópica, la puño percusión lumbar positiva y los puntos renoureterales positivos estuvieron presentes en un tercio de los pacientes. En el sedimento urinario se halló hematuria en un 40 por ciento y cristaluria en el 41 por ciento. La depuración de creatinina estuvo disminuída en el 41 por ciento de los pacientes no existiendo diferencia entre sexos. En la pielografía el 94 por ciento de los cálculos fue radiopaco, la localización más frecuente de los cálculos fue en el ureter distal y pélvis, cálculo coraliforme se presentó en el 29 por ciento de los pacientes y en su mayoría fueron mujeres. Los cálculos más frecuentes fueron los mixtos de calcio y los de oxalato de calcio más fosfato de calcio. La complicación más frecuente fue la infección urinaria. Se encuentra una alta tasa de procedimientos quirúrgicos. En el análisis de regresión múltiple se encuentra que el antecedente de haber eliminado un cálculo espontaneamente es el único factor predictivo para una nueva eliminación y que la localización y el tamaño del cálculo tienen relación con la necesidad de cirugía