The predictive relationship between baseline insulin and glucose with subclinical carotid atherosclerosis after 5 years in a multi-ethnic cohort.

BACKGROUND AND AIMS: We aimed at exploring the relationship between baseline insulin and glucose and the progression of carotid atherosclerosis in a multi-ethnic cohort. METHODS: Males and females (n = 797) of European, Chinese, South Asian and Aboriginal origin were assessed as part of the Multicultural Community Health Assessment Trial (MCHAT) study for socio-demographics, smoking status, fasting insulin and glucose at baseline. IMT, plaque area and total area were assessed after 5 years. RESULTS: A total of 545 participants returned after 5 years for a follow-up assessment. Average age of the study participants was 47.5 (SD 8.9) years. At baseline, the median and interquartile range for insulin was 62.0 (49.5) pmol/L, and glucose was 5.2 (0.60) mmol/L. Baseline glucose and insulin predicted the 5-year progression of atherosclerosis in our models, after adjusting for covariates. We found significant insulin-ethnicity interactions in the IMT model (p = 0.044) with the slope of the relationship showing that for every percentage change in insulin the Europeans experienced 7.3% more increase in IMT at 5 years than the Aboriginals. In the plaque area and total area models, there were significant glucose-ethnicity interactions (p = 0.009 and p=0.016 respectively), with the slope showing a 101% and 121% increase for plaque area and total area, respectively, in Europeans, at 5 years per percent change in glucose at baseline. Logistic regression found a significant glucose-ethnicity interaction with the presence of plaques (OR = 0.31, p = 0.03) such that compared to the Europeans, the South Asians had a lower odds of developing plaque presence. Similarly, we found glucose-ethnicity interactions in the logistic regression when comparing the Chinese to the Europeans (OR = 0.2, p=0.005), with the Chinese being less likely to develop plaque presence. CONCLUSIONS: Ethnicity modifies the predictive relationship between insulin and glucose with sub-clinical indicators of carotid atherosclerosis but not consistently so.

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.

Symptomatic bilateral delayed partial ureteral obstruction after bilateral endoscopic correction of vesicoureteral reflux with dextranomer/hyaluronic acid polymer.

Endoscopic correction of vesicoureteral reflux using dextranomer/hyaluronic acid copolymer (Deflux) is a widely used technique. Complications are uncommon, and ureteral obstruction occurs particularly infrequently. We present a case of delayed symptomatic partial bilateral ureteral obstruction after bilateral high-volume (>1.0 mL) Deflux injections that required surgical repair 16 months after injection (Clavien classification IIIb.) Bilateral delayed obstruction after endoscopic correction of vesicoureteral reflux has not been previously reported. Previous reports of immediate and delayed ureteral obstruction after Deflux injection are reviewed.

Organ-specific radiation dose rates and effective dose rates during percutaneous nephrolithotomy.

BACKGROUND AND PURPOSE: Radiation exposure during medical procedures continues to be an increasing concern for physicians and patients. We determined organ-specific dose rates and calculated effective dose rates during right and left percutaneous nephrolithotomy (PCNL) using a validated phantom model. MATERIALS AND METHODS: A validated anthropomorphic adult male phantom was placed prone on an operating room table. Metal oxide semiconductor field effect transistor dosimeters were placed at 20 organ locations in the model and were used to measure the organ dosages. A portable C-arm was used to provide continuous fluoroscopy for three 10 minute runs each to simulate a left and right PCNL. Organ dose rate (mGy/s) was determined by dividing organ dose by fluoroscopy time. The organ dose rates were multiplied by their tissue weighting factor and summed to determine effective dose rate (EDR) (mSv/s). Two-dimensional radiation distribution in the abdomen during a left-sided PCNL was visually determined using radiochromic film. RESULTS: The EDR for a left PCNL was 0.021 mSv/s ± 0.0008. The EDR for a right PCNL was 0.014 mSv/s ± 0.0004. The skin entrance was exposed to the greatest amount of radiation during left and right PCNL, 0.24 mGy/s and 0.26 mGy/s, respectively. Radiochromic film demonstrates visually the nonuniform dose distribution as the x-ray beam enters through the skin from the radiation source. CONCLUSIONS: The effective dose rate is higher for a left-sided PCNL compared with a right-sided PCNL. The distribution of radiation exposure during PCNL is not uniform. Further studies are needed to determine the long-term implications of these radiation doses during percutaneous stone removal.

Pathologic evaluation of hemostatic agents in percutaneous nephrolithotomy tracts in a porcine model.

BACKGROUND AND PURPOSE: Hemostatic agents have been suggested as an adjunct for tubeless percutaneous nephrolithotomy (PCNL). We pathologically evaluated the percutaneous tracts injected with the fibrin sealant (FS) Evicel and hemostatic gelatin matrix (HGM) Surgiflo at various time intervals to determine their absorption and tract closure rates. We also evaluated whether these agents reduced urine leak rates in a porcine model. MATERIALS AND METHODS: Percutaneous access was obtained in 19 kidneys in 10 domestic swine. The tracts were dilated to 30F using a balloon dilating catheter. Ten kidneys served as controls. Surgiflo was injected into the tract of four kidneys, and Evicel was injected into the tract of five kidneys. Intravenous urography (IVU) was performed on postoperative days (POD) 1 and 10 to 14. IVU was performed on two pigs at POD 30. The pigs were sacrificed and kidneys were harvested for pathologic evaluation. RESULTS: Two (20%) control kidneys had a urine leak on IVU on POD 1. None of the kidneys treated with HGM or FS had a urine leak on POD 1. None of the kidneys had a leak on POD 10 to 14 or POD 30. On pathologic inspection, the tracts of all the control kidneys and HGM kidneys had closed completely at POD 14. Two kidneys treated with FS had fistula at POD 6 and POD 14. At POD 30, the tracts in the control kidneys and kidney treated with HGM had completely healed. Fibrin sealant remained in the tract at POD 30. CONCLUSION: Fibrin sealant should be used with caution because it can persist in the tract for up to 30 days and may inhibit wound healing. Hemostatic gelatin matrix is the preferable agent because the tract closed by POD 10 to 14, similar to the findings in the control animals. The use of hemostatic agents in a nephroscopy tract may reduce the risk of early urine leak after tubeless PCNL.

Third prize: the role of endoscopic nephron-sparing surgery in the management of upper tract urothelial carcinoma.

INTRODUCTION: Upper tract urothelial carcinoma (UT-UC) is an uncommon disease with pronounced difference in 5-year survival for noninvasive (96%) versus invasive (17%) disease. High survival rate of early disease questioned the accepted norm of using radical nephroureterectomy (RNU) for all stages. This review assesses effectiveness of endoscopic management for UT-UC. METHODS: A review of 131 UT-UC patients seen between January 1999 and October 2009 was performed. Demographic, clinicopathologic, and outcomes data were collected and compared between patients initially managed with RNU versus those initially managed with nephron-sparing surgery (NSS). The chi-square or Fisher's exact tests for categorical variables and the Wilcoxon-Mann-Whitney test for continuous variables were used. Clinical and pathologic stages of RNU patients were evaluated with chi-square testing, whereas difference in length of stay was detected using linear regression. Recurrence rates were compared using multivariate Cox regression. RESULTS: The two arms had similar distributions of age, sex, frequency of medical comorbidities, American Society of Anesthesiologists (ASA), and Charlson scores. Mean-adjusted length of stay was 2.1 (95% confidence interval [1.6, 2.5]) and 5.5 days (95% confidence interval [5.3, 6.4]) for the NSS and RNU groups, respectively (p < 0.001). Comparison of clinical and pathologic stages of RNU patients showed a difference (p < 0.001), with under-staging noted in 32%. Men (Hazards Ratio = 2.9 [1.5-5.5], p = 0.001) and NSS patients (hazards ratio [HR] = 3.5 [1.7-7.3], p < 0.001) had threefold increased recurrence risk. CONCLUSION: NSS offered shorter hospital stay but had increased risk of recurrence. Therefore, extreme care should be made to rule out occult invasive tumors preoperatively. Patients being managed endoscopically must be informed of the necessity for close follow-up.

The digital flexible ureteroscope: in vitro assessment of optical characteristics.

INTRODUCTION: Recent advances in endoscope design have placed the charged coupled device chip on the tip of the endoscope. The image is instantly digitalized and converted into an electrical signal for transmission. Digital technology was first introduced into flexible cystoscopes/nephroscopes and subsequently into rigid and flexible ureteroscopes. Herein, we assess the image characteristics and advantages of a new generation of digital flexible ureteroscopes. METHODS: The Olympus URF-V flexible digital ureteroscope and the Olympus URF-P3 fiberoptic ureteroscope were assessed in vitro for image resolution, distortion, color representation, grayscale imaging, field of view, and depth of field. RESULTS: The digital ureteroscope had a higher resolution at 3, 5, 10, and 20 mm (25.2 lines/mm vs. 8.0, 14.1 vs. 5.0, 6.3 vs. 2.8, and 3.2 vs. 1.3), respectively. Distortion with the digital flexible ureteroscope was lower, though not statistically significant. Color representation was better with the digital ureteroscope, whereas contrast evaluation was comparable between both scopes. The digital flexlible ureteroscope produced a 5.3 times larger image size compared with the standard fiberoptic flexible uretersocpe with a narrower field of view. The depth of field was limited by light and not the optic or the camera for both ureteroscopes. CONCLUSIONS: The development of digital flexible ureteroscopes represents a significant technological advance in urology. These devices offer significantly improved resolution and color reproduction as compared with traditional fiberoptic flexible ureteroscopes. Future clinical trials are warranted to ultimately determine the advantages of these innovative endoscopes.

Reduced radiation exposure with the use of an air retrograde pyelogram during fluoroscopic access for percutaneous nephrolithotomy.

INTRODUCTION: Fluoroscopy with retrograde pyelogram is commonly used to obtain access for percutaneous nephrolithotomy (PNL). Our practice uses room air for retrograde identification of calyceal anatomy. Herein we explore whether an air pyelogram was associated with a decrease in radiation exposure compared with standard retrograde pyelogram. METHODS: We retrospectively reviewed all PNL procedures performed at our institution over the past 2 years. Of the 260 PNL procedures performed during the study period, 96 had information on radiation dosage required for analysis. The effective dose (ED) was calculated using accepted conversion tables. Multivariable linear regression was used to determine the association between ED and the use of air pyelogram controlling for factors thought to affect radiation exposure. RESULTS: Of the 96 PNL procedures included in the study, 60 (63%) were performed with an air retrograde pyelogram (AP) and 36 (37%) used contrast retrograde pyelogram (CP). Both groups were matched in terms of age, body mass index, stone burden, and number of access tracts. Multivariable linear regression showed significantly lower radiation exposure in the AP group than in the CP group (p = 0.001). There was no difference in fluoroscopy time between the two groups. Using an AP lowered the mean adjusted ED nearly twofold, from 7.67 (CI = 5.99-9.81) to 4.45 (CI = 3.68-5.38) mSv. CONCLUSIONS: An air retrograde pyelogram is associated with decreased radiation exposure during PNL when compared with a contrast retrograde pyelogram.

Factors affecting patient radiation exposure during percutaneous nephrolithotomy.

PURPOSE: We identified patient and stone characteristics that may contribute to increased radiation exposure during percutaneous nephrolithotomy and offer technique modifications to limit the radiation dose. MATERIAL AND METHODS: We reviewed the records of 96 patients who underwent percutaneous nephrolithotomy in the last 2 years. The effective radiation dose was calculated using accepted conversion tables. We performed multivariate linear regression to determine the association of the effective radiation dose with specific patient, stone and procedural characteristics. RESULTS: Mean±SD patient age was 51.5±13.4 years and 62.5% of the patients were female. Median body mass index was 32.0±9.7 kg/m2 (range 16.2 to 59.6) and the median stone burden was 4 cm2. Increased body mass index (p<0.001), higher stone burden (p=0.013), stone nonbranched configuration (p=0.002) and a greater number of percutaneous access tracts (p=0.040) were significantly associated with an increased effective radiation dose. Specifically obese patients with a body mass index of 30 to 39.9 kg/m2 had a more than 2-fold increase in the mean adjusted effective radiation dose and morbidly obese patients with a body mass index of 40 kg/m2 or greater had a greater than 3-fold increase vs that in normal weight patients with a body mass index of less than 25 kg/m2 (6.49 and 9.13 mSv, respectively, vs 2.66, p<0.001). Other stone specific parameters, including site and composition, percutaneous access site and estimated blood loss were not associated with the effective radiation dose. CONCLUSIONS: Patients with higher body mass index, greater stone burden, nonbranched stones and multiple nephrostomy access tracts are at risk for increased radiation exposure during percutaneous nephrolithotomy. Urologists must seek alternative strategies to minimize radiation exposure, such as tighter collimation to the region of interest, judicious use of magnification and the acquisition of as few images as possible during stone removal.

The impact of new methods of imaging on radiation dosage delivered to patients.

PURPOSE OF REVIEW: Ionizing radiation is produced by many of the imaging studies used in the diagnosis, management, and follow-up of patients with urolithiasis. Knowing the small, but significant, risks of solid and hematological malignancies associated with increased radiation exposure, our purpose is to discuss new imaging modalities that limit radiation exposure without compromising the valuable information needed by clinicians for appropriate management. RECENT FINDINGS: Recent studies suggest that many patients with urolithiasis may be subjected to relatively high doses of ionizing radiation during acute stone episodes and throughout the management of their disease, due, in large part, to the rapidly increasing usage of computed tomography (CT). Certain imaging modalities, most notably low-dose CT, have shown promise in reducing radiation dose to patients while maintaining comparable sensitivity and specificity to standard CT, under most conditions. SUMMARY: Urologists who use radiographic imaging in the care of their patients, must be aware of the risks of ionizing radiation. Accordingly, every effort must be made to limit radiation exposure, especially in the most susceptible populations. In our view, low-dose CT is currently the best imaging modality for patients with urolithiasis, as it offers adequate image quality with much reduced radiation exposure.

Prevalence and predictive factors for the development of de novo psychiatric illness in patients receiving androgen deprivation therapy for prostate cancer.

OBJECTIVE: Androgen deprivation therapy (ADT) remains a widely utilized modality for treatment of localized and advanced prostate cancer. While ADT-induced alterations in testosterone have demonstrated impacts on quality of life, the effects on mental health remain ill-defined. We investigated the prevalence of de novo psychiatric illness and predictive factors following ADT induction for prostate cancer. MATERIALS AND METHODS: We retrospectively reviewed patients receiving ADT for prostate cancer at our institution between 1/1989-7/2005, excluding men receiving only neoadjuvant ADT. Variables included age, race, body mass index, prostate-specific antigen (PSA), Gleason sum, clinical stage, ADT type (medical/surgical) and schedule (continuous/intermittent), and presence of pre-ADT and newly diagnosed psychiatric illness. The cohort was divided into three groups for analysis: pre-ADT psychiatric illness, de novo psychiatric illness, and no psychiatric illness. Data analysis utilized statistical software with p < 0.05 considered significant. RESULTS: Three-hundred and ninety-five patients with a mean age of 71.7 years at ADT initiation were analyzed. Thirty-four men (8.6%) were diagnosed with pre-ADT psychiatric illness. At mean follow-up of 87.4 months, 101 (27.9%) men were diagnosed with de novo psychiatric illness, most commonly including: depression (n = 57; 56.4%), dementia (n = 14; 13.9%), and anxiety (n = 9; 8.9%). On multivariate analysis, increasing pre-ADT PSA was predictive of post-ADT anxiety (p = 0.01). Overall and disease-specific survival outcomes were similar between groups. CONCLUSIONS: De novo psychiatric illness was identified in 27.9% of men. While no predictive factors were identified for de novo psychiatric illness, increasing PSA was associated with de novo anxiety. Prospective investigation using validated instruments is requisite to further delineate the relationship between ADT and psychiatric health.

Patient satisfaction after dual implantation of inflatable penile and artificial urinary sphincter prostheses.

OBJECTIVES: Since description of the transverse scrotal approach for artificial urinary sphincter (AUS) placement, simultaneous implantation of an inflatable penile prosthesis (IPP) and AUS through a single incision has been shown to constitute safe, efficient, and cost-effective treatment for men plagued by both erectile dysfunction and urinary incontinence. We present patient satisfaction outcomes after simultaneous dual implantation (DI) of an IPP and AUS. METHODS: We compared outcomes of postprostatectomy patients who underwent DI to those receiving IPP or AUS alone from 2001 to 2006. Telephone interviews using a standard questionnaire were conducted to evaluate prosthetic functionality, ease of use, and patient satisfaction. RESULTS: A total of 95 men were evaluated (31 for IPP alone, 31 for AUS alone, and 33 for DI). Daily pad usage decreased from 4.6 to 0.8 pads per day with AUS alone and 6.1 to 1.3 pads per day with DI. Patients were similarly satisfied with IPP rigidity during inflation and flaccidity during inactivation in both IPP and DI groups (4.1 to 4.4 for rigidity and 3.9 for flaccidity [1 = "unhappy" and 5 = "happy"]). Ease of scrotal pump operation was similar in all groups, as was overall prosthetic satisfaction. Most patients stated that they would recommend the DI procedure to a friend or relative (87% to 94%) or have the procedure done again (77% to 94%). CONCLUSIONS: Dual implantation produces encouraging outcomes in patient satisfaction, ease of use and functionality that are similar to those found after placement of either IPP or AUS alone.

Patterns of sexual and erectile dysfunction and response to treatment in patients receiving androgen deprivation therapy for prostate cancer.

OBJECTIVE: To investigate the incidence of patient-reported erectile (ED) and sexual dysfunction and response to treatment in men after the induction of androgen deprivation therapy (ADT) for prostate cancer, as ADT-induced changes in serum testosterone can result in changes in libido and sexual function. PATIENTS AND METHODS: We retrospectively reviewed patients receiving ADT for prostate cancer at our institution between January 1989 and July 2005; those receiving only neoadjuvant ADT were excluded. Variables included age, race, body mass index, prostate-specific antigen level before ADT, Gleason sum, clinical stage, ADT type (medical vs surgical) and schedule (continuous vs intermittent), previous treatment for prostate cancer, presence of pre-existing or new-onset diabetes mellitus (DM), and presence of ED before ADT. After ADT induction, charts were reviewed for reporting of ED, changes in libido, and initiation of ED therapy (medical or surgical). RESULTS: In all, 395 patients (mean age of 71.7 years; 59.0% African-American, 41.0% Caucasian/other, at initiation ADT) were analysed. At mean follow-up of 87.4 months, 57 (14.4%) patients reported ED; 40 of these (70%) reported new-onset ED, while 17 (30%) reported ED before ADT. Response rates were 33-80% with medical therapy, including 44% receiving phosphodiesterase-5 inhibitor monotherapy. On multivariate analysis, age <70 years (P < 0.001) and the absence of DM (P = 0.024) were associated with reporting ED after ADT. CONCLUSIONS: Patients receiving ADT for prostate cancer have variable degrees of ED. Successful outcomes are possible, particularly when implementing multimodal therapy. Younger patients and those with no DM are more likely to report ED after ADT induction.