The extracellular matrix molecules versican and hyaluronan in urethral and vaginal tissues in stress urinary incontinence.

PURPOSE: Abnormal extracellular matrix (ECM) changes are correlated with stress urinary incontinence (SUI). The ECM components versican (Vcan) and hyaluronan (HA) play key roles in regulating tissue inflammation and maintaining connective tissue homeostasis. We analyzed the localization and expression of these ECM components in urethral and vaginal tissues from a rat model of urinary incontinence and from human clinical specimens. METHODS: Nulliparous rats underwent vaginal distension (VD), a rodent model of SUI, or a sham procedure. Tissues were harvested from six rats per group at days 1, 4, and 21 for immunohistochemistry and RNA expression analysis of ECM components. Periurethral vaginal samples from female patients with SUI were also examined. RESULTS: High-intensity staining for Vcan was observed 1 day after procedure in both control and VD animals. This level of abundance persisted at day 4 in VD compared to control, with concurrent reduced messenger RNA (mRNA) expression of the Vcan-degrading enzymes ADAMTS5 and ADAMTS9 and reduced staining for the Vcan cleavage epitope DPEAAE. Abundance of HA was not different between VD and control, however mRNA expression of the HA synthase Has2 was significantly reduced in VD tissues at day 4. Abundant Vcan staining was observed in 60% of SUI patient samples, which was strongest in regions of disrupted elastin. CONCLUSION: Reduction of Vcan-degrading enzymes and HA synthases at day 4 postsurgery indicates a potential delay in ECM turnover associated with SUI. Abundant Vcan is associated with inflammation and elastin fiber network disruption, warranting further investigation to determine its role in SUI pathogenesis.

Robot-assisted vasovasostomy using a single layer anastomosis.

Of all patients who have vasectomies performed in the United States, upwards of 6% will pursue a vasectomy reversal. Currently, the gold-standard reversal procedure is a microscopic vasovasostomy utilizing either a one or two-layer vasal anastomosis. Unfortunately, most urologists do not perform these procedures as they require extensive training and experience in microsurgery. The objective of our study was to evaluate the feasibility and success rate of robot-assisted vasovasostomy performed at our institution. We completed a retrospective review of our experience with vasectomy reversal utilizing the da Vinci® Surgical System and a single layer vasal anastomosis. A successful reversal was defined as a return of sperm on semen analysis or light microscopy. Since 2009 we have completed 79 robotic vasectomy reversals, 60 of which utilized a single-layer vasal anastomosis. The average obstructive interval was 5.7 ± 2.2 years. Average operative time was 192 min. 42 patients returned for a post-operative semen evaluation at an average time of 4.3 months post-procedure revealing a success rate of 88% (37 out of 42). Post-operative semen parameters were significant for an average sperm density of 31.0 million/mL with an average motility of 29.1%. Robot-assisted vasovasostomy with a single layer anastomosis has overall success rates that are similar to that of reported microscopic vasovasostomy rates. Although more study is warranted with regard to cost, we feel as though our study demonstrates an alternative approach to vasectomy reversal that can be performed successfully by urologists trained in robotic surgery.

Changes in urine parameters after desert exposure: assessment of stone risk in United States Marines transiently exposed to a desert environment.

PURPOSE: Living in a desert environment has been associated with a higher incidence of kidney stone formation, likely because of concentrated urine output, higher production of vitamin D and genetic predisposition. We determined the changes in urinary parameters after a group of United States Marines temporarily transitioned from a temperate environment to a desert environment. MATERIALS AND METHODS: A total of 50 Marines completed a questionnaire and performed 3, 24-hour urine collections before mobilization to the desert, after 30 days in the desert and 2 weeks after returning from the desert. RESULTS: Daily urine output decreased 68% to 0.52 L despite marked increased fluid intake (17 L per day). Total daily urinary excretion of calcium, uric acid, sodium, magnesium and potassium in the desert decreased by 70%, 41%, 53%, 22% and 36%, respectively. Urinary pH decreased from 6.1 to 5.6 while in the desert, and citrate and oxalate had minimal changes. After their return from the desert, apart from a decrease of 22% in oxalate, there were no statistically significant differences from baseline. While in the desert, relative supersaturation risks of uric acid and sodium urate were increased 153% and 56%, respectively. Brushite relative supersaturation decreased 24%. After their return there was no statistical difference from baseline. CONCLUSIONS: Our findings suggest that the kidneys preserved water and electrolytes while the Marines were subjected to the desert environment. Despite this conservation, relative saturations indicate increased risk of stones in healthy men exposed to a desert environment with rapid resolution upon return.

Robotic vasovasostomy: description of technique and review of initial results.

Vasovasostomy (VV) for iatrogenic infertility is commonly employed for patients with obstructive intervals of less than 15 years, with the microsurgical technique gaining favor over use of loupe magnification due to precision suture placement. We present our technique of a robot-assisted VV and compare surgical times of staff to resident. Twenty patients with iatrogenic infertility and obstructed intervals of less than 10 years underwent robot-assisted VV, 17 utilizing a single-layer reapproximation and 3 using a double-layer reapproximation. Average patient age was 32.9 years. Following vasal exposure, the staff performed the robot-assisted anastomosis on one side followed by the resident on the opposite side. Reanastomosis times and semen analyses were recorded. Twenty patients underwent successful single- or double-layer robot-assisted vasovasostomy. Mean console time for staff to complete the vasal reconstruction was 37.6 min compared to the resident time of 54 min. Mean total operative time for all procedures was 187 min (single-layer procedure averaged 182 min compared to double-layer repair which averaged 238 min). Thirteen patients returned for follow-up semen analysis, with twelve patients demonstrating sperm within the ejaculate. Additionally, two patients reported pregnancies for a patency rate of 93%. Mean sperm density was 14 million/ml with motility of 26.4%. Robot-assisted vasovasostomy is a technically feasible procedure demonstrating adequate results on follow-up semen analysis, and can be included in training residents in robotic surgery. Additional data are needed to determine its role in the management of iatrogenic infertility.

Analysis of ureteric stent kinking forces: the role of curvature in stent failure.

OBJECTIVE: To further characterize the kinking forces and degree of curvature that result in failure of various stents, as malignant obstruction of the ureter causes failure of about half of ureteric stents. MATERIALS AND METHODS: Several stents (Silhouette 4.6 F and 6 F, Applied Medical, Rancho Santa Margarita, CA; Sof-Curl Tecoflex 6 F, Gyrus ACMI, Southborough, MA; Polaris Ultra 6 and 7 F, and Percuflex 6, 7 and 8 F stents, Boston Scientific, Natick, MA, USA) were tested. The amount of force necessary to result in kinking of the stent was measured, and the degree of curvature at failure was calculated for each stent. RESULTS: The Silhouette 4.6 and 6 F stents were the most resistant to failure by kinking and curvature. In general, smaller stents allowed more curvature before failing than their larger counterparts. CONCLUSIONS: The greater allowable curvature and resistance to kinking achieved by the Silhouette ureteric stents might result in fewer stent failures in cases of malignant obstruction or other retroperitoneal processes.

The use of adjunctive hemostatic agents for tubeless percutaneous nephrolithotomy.

Tubeless percutaneous nephrolithotomy (PCNL) is a viable option for selected patients, particularly those with solitary calculi, multiple stones located in a single location, or those that can be accessed using one access tract. Benefits over the standard PCNL include reduced hospital stay, decreased pain, and decreased urine leak from the access site that would typically occur from around the nephrostomy tube. Hemostatic agents in the form of fibrin "glue" or gelatin matrix substances have been demonstrated to be safe and effective to augment the tubeless procedure. The most appropriate sealant agent available is yet to be determined. We present a review of the contemporary literature on the use of hemostatic agents for tubeless PCNL.

Analysis of ureteral stent compression force and its role in malignant obstruction.

PURPOSE: Extrinsic ureteral obstruction can be a challenging entity for the urologist since half of the ureteral stents placed for malignant obstruction fail. We evaluated the resistance to radial compression of various stents. MATERIALS AND METHODS: Silhouette(R) 4.6Fr, 6Fr and 8Fr, Sof-Curl Tecoflex 6Fr, Resonance 6Fr, Polaris Ultra 6Fr and 7Fr, and Percuflex 6Fr and 8Fr stents were tested. The force needed to compress the stent to 50% of its original external diameter was measured at 3 locations along the stent length, including proximal, middle and distal. Statistical analysis was performed. RESULTS: Statistically greater force was required to compress the Resonance and Silhouette stents compared to all others tested. These results were maintained at all 3 locations along the stent. Only the Polaris 6Fr stent differed in resistance to compression along the stent length. CONCLUSIONS: The significantly higher forces required to compress the Resonance and Silhouette stents may translate into improved success in patients with malignant ureteral obstruction.