Optimal power settings for Holmium:YAG lithotripsy.

PURPOSE: We determined the optimal Ho:YAG lithotripsy power settings to achieve maximal fragmentation, minimal fragment size and minimal retropulsion. MATERIALS AND METHODS: Stone phantoms were irradiated in water with a Ho:YAG laser using a 365 µm optical fiber. Six distinct power settings were tested, including 0.2 to 2.0 J and 10 to 40 Hz. For all cohorts 500 J total radiant energy were delivered. A seventh cohort (0.2 J 40 Hz) was tested post hoc to a total energy of 1,250 J. Two experimental conditions were tested, including with and without phantom stabilization. Total fragmentation, fragment size and retropulsion were characterized. In mechanism experiments using human calculi we measured crater volume by optical coherence tomography and pressure transients by needle hydrophone across similar power settings. RESULTS: Without stabilization increased pulse energy settings produced increased total fragmentation and increased retropulsion (each p <0.0001). Fragment size was smallest for the 0.2 J cohorts (p <0.02). With stabilization increased pulse energy settings produced increased total fragmentation and increased retropulsion but also increased fragment size (each p <0.0001). Craters remained symmetrical and volume increased as pulse energy increased. Pressure transients remained modest at less than 30 bars even at 2.0 J pulse energy. CONCLUSIONS: Holmium:YAG lithotripsy varies as pulse energy settings vary. At low pulse energy (0.2 J) less fragmentation and retropulsion occur and small fragments are produced. At high pulse energy (2.0 J) more fragmentation and retropulsion occur with larger fragments. Anti-retropulsion devices produce more efficient lithotripsy, particularly at high pulse energy. Optimal lithotripsy laser dosimetry depends on the desired outcome.

Exercise improves bladder function in diabetic mice.

AIMS: We determined the effect of exercise on bladder dysfunction and voiding frequency in db/db mice. MATERIALS AND METHODS: Diabetic db/db female mice (BKS.Cg-Dock7m +/+ Leprdb/J strain) and their age-matched wild-type controls (WT) were equally divided into sedentary and exercise groups. Mice were exercised for 1 hr everyday for 8 weeks (speed of 5.2 m/min). We performed a voiding pattern test, cystometric analysis and reactivity of isolated bladder strips in WT and db/db mice, both sedentary and exercised. RESULTS: Diabetes increased the frequency of voiding, bladder capacity, and residual volume. Exercise decreased voiding frequency in db/db mice; voiding frequency was 5.8 ± 0.5 (db/db exercise) versus 10.8 ± 1.1 (db/db control, P < 0.001). In cystometric analysis, the bladder capacity of db/db sedentary mice was 0.27 ± 0.05 ml and was 0.14 ± 0.02 ml in the db/db exercise group (P < 0.05), whereas the residual volume was 0.2 ± 0.03 ml in db/db sedentary mice and 0.06 ± 0.02 ml in db/db Ex mice. Isolated strips of bladder muscle from sedentary db/db mice were more responsive to carbachol than strips from db/db exercise mice. Exercise did not improve the urodynamic properties of WT mice, both sedentary and exercised. CONCLUSIONS: Exercise improves bladder function in diabetic mice by reducing voiding frequency and improving urodynamic parameters.

Noninfectious penile lesions.

Family physicians commonly diagnose and manage penile cutaneous lesions. Noninfectious lesions may be classified as inflammatory and papulosquamous (e.g., psoriasis, lichen sclerosus, angiokeratomas, lichen nitidus, lichen planus), or as neoplastic (e.g., carcinoma in situ, invasive squamous cell carcinoma). The clinical presentation and appearance of the lesions guide the diagnosis. Psoriasis presents as red or salmon-colored plaques with overlying scales, often with systemic lesions. Lichen sclerosus presents as a phimotic, hypopigmented prepuce or glans penis with a cellophane-like texture. Angiokeratomas are typically asymptomatic, well-circumscribed, red or blue papules, whereas lichen nitidus usually produces asymptomatic pinhead-sized, hypopigmented papules. The lesions of lichen planus are pruritic, violaceous, polygonal papules that are typically systemic. Carcinoma in situ should be suspected if the patient has velvety red or keratotic plaques of the glans penis or prepuce, whereas invasive squamous cell carcinoma presents as a painless lump, ulcer, or fungating irregular mass. Some benign lesions, such as psoriasis and lichen planus, can mimic carcinoma in situ or squamous cell carcinoma. Biopsy is indicated if the diagnosis is in doubt or neoplasm cannot be excluded. The management of benign penile lesions usually involves observation or topical corticosteroids; however, neoplastic lesions generally require surgery.

Paediatric painful bladder syndrome/interstitial cystitis: diagnosis and treatment.

To describe the pathophysiology, diagnosis and controversies surrounding the diagnosis and pharmacological treatments of painful bladder syndrome/interstitial cystitis (PBS/IC) in children, we reviewed adult and paediatric literature pertaining to PBS/IC. Paediatric PBS/IC presents similarly to adult PBS/IC. The diagnosis is made by exclusion. Paediatric PBS/IC patients complain most commonly of urinary frequency, and abdominal pain occurs in up to 88% of affected children. Enuresis may also be a presenting complaint. Urinalysis and urine cultures are unremarkable. Management of paediatric PBS/IC is similar to that of adult PBS/IC, and non-surgical management includes dietary, lifestyle and pharmacological therapy. Pharmacological options include pentosan polysulfate, amitriptyline, hydroxyzine, cimetidine or intravesical therapies (dimethyl sulfoxide or 'therapeutic solution').

Review of exercise and the risk of benign prostatic hyperplasia.

It has been long appreciated that a healthy lifestyle plays a critical role in cardiovascular health. It is now apparent that the same is true in the development of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Since 1995, 14 studies have been identified that investigate the clinical relationship between exercise and BPH/LUTS. No randomized controlled trials have been performed, but useful prospective cohort data originating from recent publications on the medical treatment of BPH and prevention of prostate cancer are available. Most of the literature supports a clinically significant, independent, and strong inverse relationship between exercise and the development of BPH/LUTS. Several mechanisms for this relationship have been proposed, including decreased sympathetic tone, avoidance of metabolic syndrome, and reduced oxidative damage to the prostate.

A validated mouse model for orthotopic bladder cancer using transurethral tumour inoculation and bioluminescence imaging.

OBJECTIVES: To describe a technique for transurethral tumour inoculation, bioluminescence imaging (BLI) and validation of this approach using ex vivo magnetic resonance imaging (MRI), as a reproducible and quantifiable model of orthotopic bladder cancer is required to enable preclinical pharmacological studies of intravesically administered anticancer agents and the use of BLI provides a sensitive method to monitor tumour growth over time. MATERIALS AND METHODS: Human KU-7 bladder tumour cells were transduced with a lentiviral construct to stably express the firefly luciferase gene. These cells were then inoculated in female nude mice by intravesical instillation. BLI was performed weekly and the mice were killed after 4 weeks. Ex vivo MRI and whole-mount step-sections were obtained to assess bladder tumour volume. RESULTS: KU-7 tumour cells were highly tumorigenic and were successfully inoculated in 96% of mice. After 4 weeks, all tumours were confined to the mucosa and submucosa (

Calibration of a novel, laparoscopic, 12-mm, ultrasound, image-guided, high-intensity focused ultrasound probe for ablation of renal neoplasms.

OBJECTIVE: To calibrate a 12-mm high-intensity focused ultrasound (HIFU) probe to produce histologically verifiable complete tissue necrosis through thermal energy delivery while maintaining safety in ablation of porcine renal tissue. METHODS: The study was approved by the animal research committee at our institution. A HIFU probe on a fixed arm was introduced, and ablation was subsequently carried out robotically (under computer control) at 2 planned locations within each kidney at varying energy levels. After 4 days of survival, kidneys were retrieved and pathologic analysis of the lesions was carried out for necrotic volume. Planned volume was compared with pathologic necrotic volume. RESULTS: A series of optimizations were carried out as the experiment progressed. Near optimal ablation zone dimensions with complete cell death were achieved when the energy density was between 400 and 460 calories/cm(3). Pathologic analysis demonstrated the average ratio of necrotic zone volume to planned zone volume was 1.0 (standard deviation, 0.18) in the 7 lesions with energy density between 400 and 460 calories/cm(3). All animals survived the surgeries, and no device-related complications were identified during the study. No acute renal failure was identified in analysis of the blood work. CONCLUSION: A novel 12-mm laparoscopic HIFU probe was successfully calibrated for the ablation of porcine renal tissue. The safety profile of the Sonatherm probe was found to be excellent with no complications identified.

Comparison of measured renal tumor size versus R.E.N.A.L. nephrometry score in predicting patient outcomes after robot-assisted laparoscopic partial nephrectomy.

Partial nephrectomy (PN) is a technically challenging procedure, making selection of appropriate patients paramount to a successful operation. To identify patients at increased risk of an adverse outcome after PN, there are a number of scoring systems available. The nephrometry score was initially described in a series of laparoscopic and open partial and radical nephrectomies. We compare the association of the nephrometry score with perioperative outcomes in a population of robot-assisted partial nephrectomies. A total of 119 patients were retrospectively reviewed. Correlation and regressional analysis was performed. We identified the separate variables R, E, N, and L to have limited correlation and no predictive value to patient outcomes. Nephrometry score and grade were found to have stronger correlation and predictive value than the individual components of the R.E.N.A.L. nephrometry score. Size of tumor measured on a continuous scale was found to have the strongest correlation and predictive value to outcomes. Outcomes predicted included operative time, length of stay, warm ischemia time, and entry into the collecting system.