Ureteroscopic treatment of patients with small, painful, non-obstructing renal stones: the small stone syndrome.

AIMS: Although it is thought that renal colic results from urinary tract obstruction, some patients evaluated for renal colic are found to have no source for their pain other than small, non-obstructing renal calyceal stones. We refer to this as "the small stone syndrome". We aim to determine if small non-obstructing calyceal stones may also cause pain and that treatment may relieve this pain. METHOD: A retrospective chart review was performed to identify patients with non-obstructing calyceal stones (≤ 4 mm in diameter) evaluated for flank pain and treated by ureteroscopy. Patients completed a follow-up questionnaire regarding pre- and postoperative pain and quality of life (QOL). RESULTS: 13 patients were included in the analysis. Mean stone diameter was 3 mm (range 1.5 - 4.0 mm). Following ureteroscopy, 11 (85%) patients reported complete resolution of pain and 2 (15%) reported partial resolution. 12 patients were able to describe preoperative and postoperative QOL and of these, 8 (67%) had improved QOL, 4 (33%) had no change, and none reported worsening. Follow-up imaging was available in 10 patients: stone free in 6 (60%), reduction in stone size in 3 (30%), and stone unchanged in 1 (10%). CONCLUSIONS: Ureteroscopic treatment of painful small, non-obstructing renal calyceal stones achieved complete or partial resolution of pain in all patients and improvement in QOL in a majority of patients.

Transpelvic Magnetic Stimulation Enhances Penile Microvascular Perfusion in a Rat Model: A Novel Interventional Strategy to Prevent Penile Fibrosis after Cavernosal Nerve Injury.

PURPOSE: Penile microvascular dysfunction is a known contributor to erectile dysfunction (ED) and penile fibrosis has been shown to impair microvascular perfusion (MVP). Our objectives were to: (i) determine beneficial effects of TPMS to modulate penile MVP, (ii) determine its mechanism, (iii) evaluate impact of cavernosal nerve injury (CNI) on penile MVP, and (iv) determine time-course of cavernosal tissue elastin changes after CNI in rats. MATERIALS AND METHODS: Adult male rats (n=5) were anesthetized and subjected to TPMS (13%, 15%, and 17%) and MVP changes were recorded using laser speckle contrast imaging (LSCI). Another group of male rats were subjected to either bilateral cavernosal nerve injury (CNI; n=7) or sham surgery (n=7). After recovery, animals were monitored for MVP using LSCI before and after TPMS. Rat penile tissues were harvested and analyzed for fibrosis using a marker for elastin. RESULTS: Rat TPMS resulted in a stimulus dependent increase in MVP; maximal perfusion was observed at 17%. L-N(G)-Nitroarginine methyl ester (L-NAME) resulted in a marked decrease in TPMS induced MVP increase (393.33 AU vs. 210.67 AU). CNI resulted in 40% to 50% decrease in MVP. CNI produced a remarkable increase in elastin deposits that are noticeable throughout the cavernosal tissues post injury. CONCLUSIONS: TPMS is a novel and non-invasive intervention to improve penile MVP after CNI. Potential application includes treatment of ED and sexual function preservation following cancer treatment, possibly through improved penile hemodynamics that might help prevent penile hypoxia and fibrosis.

Differential renal function estimation using computerized tomography based renal parenchymal volume measurement.

PURPOSE: Nuclear renal scan is currently the gold standard imaging study to determine differential renal function. We propose helical computerized tomography as a more efficient way to gain renal function information. Renal parenchymal volume is measured and percent total renal volume is used as a surrogate marker for differential renal function. MATERIALS AND METHODS: Computerized tomography and diuretic enhanced nuclear renal scan were performed in 33 patients with chronic obstruction. Computerized tomography was contrast enhanced in 23 cases and nonenhanced in 10. Diagnoses included ureteropelvic junction obstruction, ureteral stricture and extrinsic compression. Using semiautomated boundary delineation with manual editing method the parenchymal volume of each kidney was measured and percent renal volume was calculated. Percent renal volume was compared with percent renal function, as determined by nuclear renal scan. Correlations between the 2 measures were evaluated using the Spearman or Pearson coefficient. RESULTS: Strong correlations were observed between percent renal function and percent renal volume in all cases (r = 0.90, p <0.001), including the enhanced (r = 0.87, p <0.001) and nonenhanced (r = 0.95, p <0.001) groups. Moderately strong correlations were noted in the less than 40% (r = 0.76, p <0.001) and less than 30% (r = 0.64, p = 0.015) renal function subgroups. CONCLUSIONS: Differential renal volume measured from computerized tomography strongly correlates with differential renal function on nuclear renal scan for normal and chronically obstructed kidneys. Computerized tomography may serve as a single radiological diagnostic study for anatomical and functional assessment in patients in whom a poorly functioning kidney is suspected.

Cohen cross-trigonal ureteral reimplantation: is a one-year postoperative renal ultrasound scan necessary after normal initial postoperative ultrasound findings?

OBJECTIVES: To determine the utility of the 1-year postoperative renal ultrasound scan in children undergoing uncomplicated Cohen cross-trigonal ureteral reimplantation. METHODS: A retrospective review of 108 patients (233 ureters) who had undergone uncomplicated Cohen cross-trigonal ureteral reimplantation during a 6.5-year period with a postoperative follow-up of 1 year was performed. Renal ultrasound scans were obtained at 1 month and 1 year postoperatively. RESULTS: Of the 108 patients who had undergone ureteral reimplantation, 26 patients (24%) had mild to moderate hydronephrosis at 1 month postoperatively. Of these 26 patients, 20 had preexisting hydronephrosis and 6 had new hydronephrosis. Of the 20 patients with preoperative hydronephrosis, 19 (95%) had similar hydronephrosis on the 1-month postoperative ultrasound scan and in 1 (5%), the hydronephrosis had resolved. At 1 year, 13 (69%) of the 20 patients with preoperative hydronephrosis had stable hydronephrosis, and it resolved in 6 (31%). In the 6 patients with new-onset hydronephrosis at 1 month postoperatively, the hydronephrosis had resolved by 1 year in 4 patients (67%) and was mild in 2 (33%). Three patients developed transient obstruction requiring stent placement. CONCLUSIONS: It has been recommended that a renal ultrasound scan be obtained in children 1 year after open ureteral reimplantation to rule out delayed obstruction. Our results suggest this is of low yield in patients with uncomplicated open ureteral reimplantation.