Preoperative Bladder Urine Culture as a Predictor of Intraoperative Stone Culture Results: Clinical Implications and Relationship to Stone Composition

Purpose We examine the relationship between urine and stone cultures in a large cohort of patients undergoing percutaneous stone removal and compare the findings in infectious vs metabolic calculi. Materials and Methods A total of 776 patients treated with percutaneous nephrolithotomy who had preoperative urine cultures and intraoperative stone cultures were included in the study. Statistical analysis used chi-square or logistic fit analysis as appropriate. Results Preoperative urine culture was positive in 352 patients (45.4%) and stone cultures were positive in 300 patients (38.7%). There were 75 patients (9.7%) with negative preoperative cultures who had positive stone cultures, and in patients with both cultures positive the organisms differed in 103 (13.3%). Gram-positive organisms predominated in preoperative urine and stone cultures. Conclusions Preoperative urine cultures in patients undergoing percutaneous nephrolithotomy are unreliable as there is a discordance with intraoperative stone cultures in almost a quarter of cases. There has been a notable shift toward gram-positive organisms in this cohort of patients

Shock wave lithotripsy targeting of the kidney and pancreas does not increase the severity of metabolic syndrome in a porcine model

PURPOSE: We determined whether shock wave lithotripsy of the kidney of pigs with metabolic syndrome would worsen glucose tolerance or increase the risk of diabetes mellitus. MATERIALS AND METHODS: Nine-month-old female Ossabaw miniature pigs were fed a hypercaloric atherogenic diet to induce metabolic syndrome. At age 15 months the pigs were treated with 2,000 or 4,000 shock waves (24 kV at 120 shock waves per minute) using an unmodified HM3 lithotripter (Dornier MedTech, Kennesaw, Georgia). Shock waves were targeted to the left kidney upper pole calyx to model treatment that would also expose the pancreatic tail to shock waves. The intravenous glucose tolerance test was done in conscious fasting pigs before lithotripsy, and 1 and 2 months after lithotripsy with blood samples taken for glucose and insulin measurement. RESULTS: Pigs fed the hypercaloric atherogenic diet were obese, dyslipidemic, insulin resistant and glucose intolerant, consistent with metabolic syndrome. Assessments of insulin resistance, glucose tolerance and pancreatic β cell function from fasting plasma glucose and insulin levels, and the glucose and insulin response profile to the intravenous glucose tolerance test were similar before and after lithotripsy. CONCLUSIONS: The metabolic syndrome status of pigs treated with shock wave lithotripsy was unchanged 2 months after kidney treatment with 2,000 high amplitude shock waves or overtreatment with 4,000 high amplitude shock waves. These findings do not support a single shock wave lithotripsy treatment of the kidney as a risk factor for the onset of diabetes mellitus

Therapy-resistant nephrolithiasis following renal artery coil embolization

Background Transcatheter renal artery embolization is an effective and minimally invasive treatment option for acute renal bleeding. Early post-interventional complications include groin hematoma, incomplete embolization, coil misplacement and coil migration. Late complications are rare and mostly related to coil migration. Case presentation A 22-year-old woman with a history of recurrent stone disease and a lumbal meningomyelocele underwent bilateral open pyelolithotomy for bilateral staghorn calculi. Post-operatively, acute hemorrhage of the left kidney occurred and selective arterial coil embolization of a lower pole interlobular renal artery was performed twice. Four years after this intervention the patient presented with a new 15.4 mm stone in the lower calyx of the left kidney. After two extracorporeal shock wave lithotripsy treatments disintegration of the stone was not detectable. Therefore, flexible ureterorenoscopy was performed and revealed that the stone was adherent to a partially intraluminal metal coil in the lower renal calyx. The intracalyceal part of the coil and the adherent stone were successfully removed using the holmium laser. Conclusion Therapy-resistant nephrolithiasis was caused by a migrated metal coil, which was placed four years earlier for the treatment of acute post-operative renal bleeding. Renal coils in close vicinity to the renal pelvis can migrate into the collecting system and trigger renal stone formation. Extracorporeal shock wave lithotripsy seems to be inefficient for these composite stones. Identification of these rare stones is possible during retrograde intrarenal surgery. It also enables immediate stone disintegration and removal of the stone fragments and the intraluminal coil material