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.

Impact of statins on nephrolithiasis in hyperlipidemic patients: a 10-year review of an equal access health care system.

AIM: To investigate the impact of statin medications on urinary stone formation in hyperlipidemic patients. MATERIAL AND METHODS: We searched outpatient military electronic health records from the Southwestern United States to identify adult patients with hyperlipidemia and urolithiasis. Military facilities serve active duty members, retirees, and their immediate family members. We created two predictor variables - with and without statin. The outcome variable was a diagnosis of urolithiasis. RESULTS: The inception cohort included 57,232 subjects with hyperlipidemia and 1,904 subjects with nephrolithiasis. Patients taking statin medications had significantly less stone formation compared to patients not taking statin medications (3.1% vs. 3.7%, univariate OR = 0.83, 95% CI 0.76 - 0.91, p < 0.001). Statins patients were significantly older (59 vs. 45 years, p < 0.001), more likely to be female (38% vs. 34%, p < 0.001) and have co-morbidities (obesity, hypertension, diabetes, heart disease; all p < 0.001). Multivariate analysis indicated that statin medications had a protective effect against stone formation (OR = 0.51, 95% CI 0.46 - 0.57, p < 0.001), after adjusting for age, sex, and comorbidities. The risk of nephrolithiasis was not only additive for diabetes mellitus, hypertension, and obesity; more importantly it was attenuated with addition of statin use. CONCLUSION: Statin medications are associated with reduced risk of urinary stones. This is the first study to demonstrate the impact of statins on nephrolithiasis. Further prospective studies are necessary to validate these findings that treatment of hyperlipidemia reduces stone risk formation.

Percutaneous stone surgery using a tubeless technique with fibrin sealant: report of our first 107 cases.

UNLABELLED: Study Type--Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? Small case series support the safety and efficacy of tubeless PCNL with fibrin sealant. However, there is a paucity of data from larger case series supporting this approach. To our knowledge, this is among the largest tubeless PCNL series. We found the use of fibrin sealant for tubeless PCNL was associated with excellent stone-free rates (approaching 90%), short hospitalisation, and low complication rates. Tubeless PCNL with nephrostomy tract fibrin sealant appears to be viable option for appropriately select patients. OBJECTIVE: • To report on our first 107 cases of tubeless percutaneous nephrolithotomy (PCNL) using fibrin sealant as a haemostatic agent within the access tract. PCNL is the preferred treatment for patients with large renal stones, and the tubeless technique with the use of fibrin sealant has recently gained popularity. PATIENTS AND METHODS: • We performed a retrospective review of single-access, PCNL cases performed without a nephrostomy tube from January 2002 to July 2008. • Nephrostomy tracts were sealed at the conclusion of each procedure with fibrin-containing haemostatic agents. • We evaluated demographic variables, tracked complications, and compared pre- and postoperative haemoglobin, haematocrit and creatinine levels. • On postoperative day 1 computed tomography was used to determine stone-free rates. • Student's t-test calculations were used to determine statistical significance at P ≤ 0.05. RESULTS: • In all, 59 men and 48 women with a mean age of 43 years were included in the analysis of 107 cases. The mean stone size was 2.9 cm(2) and the average hospital stay was 1.07 days. • Pre- and postoperative changes in serum haemoglobin and serum creatinine were not statistically different. Postoperative haematocrit declined by a mean of 4.5% (P ≤ 0.05), but no patients required a transfusion. • Stone-free rates were 72% overall, and 90% when excluding patients with residual fragments of <4 mm. • Complications included seven asymptomatic subcapsular haematomas, one pseudoaneurysm requiring selective embolization, one urine leak, and five return visits to the emergency room for pain. CONCLUSIONS: • The use of fibrin sealant in this large tubeless PCNL series was associated with favourable stone-free rates, short hospital stays, and low complication rates with no significant bleeding. • Tubeless PCNL with nephrostomy tract fibrin sealant appears to be a viable option for appropriately selected patients, but future randomised trials are warranted.

Genitourinary abnormalities in an asymptomatic screening population: findings on virtual colonoscopy.

INTRODUCTION: The true incidences of genitourinary conditions in the modern era are not completely known. We sought to determine the incidence of genitourinary abnormalities in a group of asymptomatic adult patients undergoing axial imaging with virtual colonoscopy. METHODS: We performed a post-hoc analysis of imaging results from a prospective, IRB-approved study that randomized patients to screening "virtual" CT colonography (CTC) followed by standard endoscopic colonoscopy. CTC scans were reviewed separately by an independent radiologist and a urologist for genitourinary abnormalities. Genitourinary abnormalities were characterized as of minor, moderate, or major clinical significance. Identified nephroliths were categorized by location, laterality, size, and number. Student's t-tests and Fisher's exact-tests were used for continuous and categorical variables as appropriate. RESULTS: Of 490 patients undergoing CTC and eligible for analysis, no genitourinary abnormalities were found in 294 (60%), minor genitourinary abnormalities were found in 100 (20.4%), moderate genitourinary abnormalities were found in 86 (17.6%), and major genitourinary abnormalities were found in 10 (2%). Renal cysts (n = 60, 12%) were the most common minor urologic findings. Moderate and major genitourinary findings of nephrolithiasis, adrenal adenomas, and renal masses were noted in 13.9%, 3%, and 2% of the population, respectively. The largest stone was 1.2 cm, and the smallest was 1 mm; while 59% had stones < 3mm, 20% between 3 mm and 5 mm, 18% between 5 mm and 10 mm, and 3% > 10 mm in size. Unilateral stones were found in 85%, while bilateral were found in 15%, and the average number of stones was 2, (range 1 - 16). Age and male sex were significantly associated with moderate or major genitourinary findings p = 0.04 and p = 0.05, respectively. CONCLUSIONS: CT colonography in an asymptomatic screening population helped to identify nephrolithiasis in 13.9%. Moderate and major urologic abnormalities were found in 20% of the cohort. Risk factors included male sex and older age.

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.

Do nonspecific deep corticomedullary sutures performed during partial nephrectomy adequately control major vascular and collecting system injury?

OBJECTIVE: To critically evaluate the effectiveness of placing nonspecific deep corticomedullary sutures in the setting of major vascular and collecting system injury during laparoscopic partial nephrectomy (LPN). We also aimed to evaluate the incidence of ischaemic injury to the remaining renal remnant because of these sutures, as many laparoscopic centres have adopted this practice. MATERIALS AND METHODS: We performed open PN on eight porcine kidneys. Both the artery and vein were clamped. The ureter was transected and tied around an angiocatheter for evaluating collecting system integrity both before and after corticomedullary suturing. The renal artery was cannulated for angiography before and after the corticomedullary suturing. The rate of bleeding was also assessed before and after corticomedullary suturing. RESULTS: There was marked arterial bleeding and large collecting system injury induced in all kidneys. Two of the eight renal units continued to have significant arterial bleeding after the deep corticomedullary sutures were placed. All of the eight units had at least a small urinary leak after suturing, with three having medium-to-large leaks. In four of the renal units, there were major segmental vessels occluded by the sutures, as detected by angiography. CONCLUSIONS: The practice of placing nonspecific deep corticomedullary sutures, during PN, may not adequately control major vascular and collecting system injury. In addition, segmental vessels supplying remnant renal tissue are often affected; thereby further compromising function because of devascularization. The search for the best technique for LPN continues.

Practice patterns of primary care providers and urologists for use of medical expulsion therapy.

PURPOSE: Alpha-blockers and calcium channel blockers have shown promise for medical expulsion therapy (MET) of distal ureteral calculi < 1 cm in size. Although MET has been discussed in urology for some time, little has been written about MET in the emergency medicine and primary care literature. We sought to evaluate current practice patterns of MET among urologists, emergency medicine physicians, other primary care providers, and frontline military care providers. METHODS: Web-based, self-developed survey to assess the current practice patterns of providers for the initial management of uncomplicated ureteral calculi, and specifically, their frequency of using MET. Cross-tabulation strategies utilizing compiled survey results were used to assess survey outcomes and determine prevalence values for understanding, familiarity, and therapeutic interventions for nephrolithiasis. RESULTS: Of 293 medical professionals, 114 (39%) were urologists, 55 (48%) of which were fellowship trained in endourology. Fifty-six (19%) were emergency medicine physicians, 22 (8%) were family practitioners, and 19 (7%) were internists and other primary care physicians. Other physician subspecialists and medical paraprofessionals comprised the remaining 34%. Overall 27% of respondents were unfamiliar with MET for expulsion of uncomplicated ureteral stones, including 13% of staff physicians, 21% of emergency medicine doctors, 56% of family practitioners, 40% of internists, and 43% of other primary care providers. The overall prevalence of use of MET was 45%. All urologists were familiar with MET, but 31% rarely, never, or only sometimes used this therapy. Specifically, urologists, emergency physicians, family practitioners, internists, and other providers, usually or always used MET 69%, 55%, 16%, 16%, and 27%, of the time, respectively. In academic institutions, 71.6% use MET usually or almost always compared to 36% in military healthcare settings and 47% in other practice settings. Tamsulosin is the most widely used medication for MET, accounting for 57% of MET use. Factors identified that inhibit more widespread use of MET include, physician unfamiliarity with MET (72%), the belief that MET is not effective (10%), patient unwillingness to undergo MET (5%), and medications not covered by insurance plans (4%). CONCLUSION: While MET has been established as a reasonable adjunct for management of uncomplicated ureteral stones, it may be underutilized due to physician unfamiliarity with this type of treatment and perceived ineffectiveness. This therapy may be of particular benefit to forward deployed forces. Education programs and practice-specific guidelines to target this audience may help to improve the dispersion of MET into the medical community.

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.

Testis cancer: a 20-year epidemiological review of the experience at a regional military medical facility.

PURPOSE: Testis cancer is the most common solid malignancy in the young adult population and the incidence in this population is increasing. We present a 20-year epidemiological review of testis cancers treated at our institution. MATERIALS AND METHODS: The records of testis cancer cases diagnosed between January 1988 and June 2007 were reviewed. Patient demographics, cancer histology and stage, adjuvant therapy, temporal trends and survival data are presented. Our experience was compared to trends published in the SEER (Surveillance, Epidemiology and End Results) database and the National Cancer Database. RESULTS: A total of 338 testis cancers (330 germ cell tumors) were diagnosed during the study period. Median patient age at diagnosis was 26.6 years vs 34 in the SEER database. We observed a temporal increase in stage I tumors (57% to 75%) and a decrease in the proportion of seminomas (52% to 43%) during the study period. In terms of adjuvant therapy for stage I seminoma the use of radiotherapy decreased (91% to 75%), while the use of chemotherapy increased (1.5% to 7.5%). For stage I nonseminomatous germ cell tumors the use of adjuvant chemotherapy increased (12% to 20%), while the use of staging retroperitoneal lymph node dissection decreased (88% to 63%). Five-year cancer specific survival was 97.7%. CONCLUSIONS: We are seeing an increase in localized disease at diagnosis, an increase in surveillance for stage I disease and 5-year survival in excess of 95%, similar to data in SEER and the National Cancer Database. However, unlike in SEER and the National Cancer Database, our patients are younger, we are seeing less seminoma and we are performing significantly more staging retroperitoneal lymph node dissection.

Comparison of a novel radially dilating balloon ureteral access sheath to a conventional sheath in the porcine model.

PURPOSE: Traditional ureteral access sheaths rely on tapered dilators and the Dotter principle of axial force to gain access into the ureter. We compared the performance of a novel balloon expandable ureteral access sheath using radial dilatation with that of a conventional ureteral access sheath. MATERIALS AND METHODS: Ten farm pigs underwent randomized placement of the novel sheath in 1 ureter and a conventional ureteral access sheath in the contralateral ureter followed by videotaped ureteroscopy. Acute study end points included maximum and mean force of sheath insertion and removal, saline flow rate and subjective urothelial damage following sheath insertion/inflation. Additionally, blinded reviewers rated urothelial damage on digitally recorded video following sheath removal. Chronic data included gross and histological ureteral analysis at 30 days. RESULTS: The novel ureteral access sheath inserted with less maximum force (0.36 vs 1.48 pounds, p <0.001) and less average force (0.11 vs 0.49 pounds, p = 0.001). The flow rate during 5 minutes was higher in the new sheath (90.0 vs 80.6 cc per minute, p <0.05). Withdrawal forces were not statistically different between the sheaths. The novel sheath also had a lower subjective trauma scale rating (4.2 vs 6.1, p <0.05). Eight blinded reviewers determined that the novel ureteral access sheath resulted in less total urothelial tear length (1.3 vs 2.7 cm, p = 0.03) and less visible ureteral damage in all animals except 1 (p = 0.04). CONCLUSIONS: The novel balloon expandable ureteral access sheath had easier insertion and a better flow rate, and caused less urothelial trauma in this porcine model. This ureteral access sheath offers a promising new option for ureteral access. A randomized clinical trial is in progress to assess the benefits of this new ureteral access sheath.

Prospective randomized trial comparing shock wave lithotripsy and ureteroscopy for lower pole caliceal calculi 1 cm or less.

PURPOSE: The optimal management of lower pole renal calculi is controversial. We compared shock wave lithotripsy (SWL) and ureteroscopy (URS) for the treatment of patients with small lower pole stones in a prospective, randomized, multicenter trial. MATERIALS AND METHODS: A total of 78 patients with 1 cm or less isolated lower pole stones were randomized to SWL or URS. The primary outcome measure was stone-free rate on noncontrast computerized tomography at 3 months. Secondary outcome parameters were length of stay, complication rates, need for secondary procedures and patient derived quality of life measures. RESULTS: A total of 67 patients randomized to SWL (32) or URS (35) completed treatment. The 2 groups were comparable with respect to age, sex, body mass index, side treated and stone surface area. Operative time was significantly shorter for SWL than URS (66 vs 90 minutes). At 3 months of followup 26 and 32 patients who underwent SWL and URS had radiographic followup that demonstrated a stone-free rate of 35% and 50%, respectively (p not significant). Intraoperative complications occurred in 1 SWL case (unable to target stone) and in 7 URS cases (failed access in 5 and perforation in 2), while postoperative complications occurred in 7 SWL and 7 URS cases. Patient derived quality of life measures favored SWL. CONCLUSIONS: This study failed to demonstrate a statistically significant difference in stone-free rates between SWL and URS for the treatment of small lower pole renal calculi. However, SWL was associated with greater patient acceptance and shorter convalescence.

Important military role for medical expulsion therapy of urolithiasis.

Kidney stones are a major problem affecting military personnel and may lead to decreases in individual and unit readiness. Various medications, including steroids, calcium channel blockers, and alpha-adrenergic antagonists have been shown to aid in the spontaneous passage of ureteral calculi. Several recent randomized clinical trials have shown that selective alpha blockers improve stone passage rates. Although medical expulsion therapy has been the subject of a number of urologic investigations, to date there has been very little written about the acute medical management of urinary stones in the emergency medicine and primary care literature. Medical management of ureteral stones may offer forward-deployed forces a useful adjunct for the management of ureterolithiasis thereby greatly reducing the need for potentially hazardous evacuations out of theater.

Retroperitoneoscopic radical nephrectomy for renal-cell carcinoma during twin pregnancy.

Renal-cell carcinoma (RCC) is rarely reported during pregnancy. Both the open and the laparoscopic approach to nephrectomy have been used effectively and safely in pregnant patients with RCC. We report a unique case of a 52-year-old woman found to have RCC during twin gestation who was treated with retroperitoneoscopic radical nephrectomy, one of the first such cases managed by this approach.

Practice patterns of ureteral stenting after routine ureteroscopic stone surgery: a survey of practicing urologists.

BACKGROUND: Controversy exists regarding the need for ureteral stent insertion after routine ureteroscopic stone surgery. We designed a questionnaire to assess and better understand the practice patterns of urologists for stent applications. MATERIALS AND METHODS: A 26-question survey was distributed to 570 community and academic urologists. The answers were anonymously tabulated to determine the practice patterns for stent placement. RESULTS: Of the 173 respondents, 97.7% performed ureteroscopic surgery, with the majority (77%) performing 1 to 10 procedures per month. Sixty-eight percent of urologists considered more than 70% of their ureteroscopic procedures "routine." Only 21% of urologists dilated the ureteral orifice more than 90% of the time. Those who dilated the ureteral orifice used a balloon (43%), ureteral access sheath (13.5%), or both (21%). The use of an access sheath did not change stenting practices for 75% of urologists. Patterns vary with regard to length of indwelling time, with 85% of urologists maintaining the stent for fewer than 7 days. Most urologists use either cystoscopy (42%) or pull-suture in clinic (37%) to remove stents. Patient tolerance is the most significant problem with stents reported by 97.6% of urologists. The respondents were divided into three experience-based groups: group 1, <2 years of experience; group 2, 2 to 10 years; and group 3, >10 years. Using Fisher's exact test, there were no statistically significant differences between the groups. CONCLUSION: A wide variability exists among urologists in the practice patterns of stent insertion after routine ureteroscopic surgery. Most consider their procedures routine and are more likely to place stents after ureteral dilation despite growing evidence to the contrary. Knowledge of the varied practices may aid less experienced urologists in their decision to insert a stent after ureteroscopy.

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.

Effect of freeze time during renal cryoablation: a swine model.

BACKGROUND AND PURPOSE: Cryotherapy provides a minimally invasive treatment for small renal tumors via an open, percutaneous, or laparoscopic approach. We sought to determine the most appropriate duration of freezing and the number of probes necessary to produce cell death without concomitant morbidity. MATERIALS AND METHODS: Nine domestic female pigs were divided into three groups of three animals each. Each group underwent a single freeze cycle with a commercially available cryotherapy device with 3.4-mm probes: group 1 for 5 minutes, group 2 for 10 minutes, and group 3 for 15 minutes. The right kidney was treated with a single probe, the left with a double probe. Animals were permitted to survive for an average of 4.8 days (range 4-7 days), after which the kidneys were harvested. A single pathologist examined the kidneys for gross and histologic changes. Evidence of complications (fistula, bleeding, bowel injury) was documented at the time of necropsy. RESULTS: For group 1, the temperature obtained with a single probe 5, 10, 15, and 20 mm from the probe was -57 degrees C, 3 degrees C, 25 degrees C, and 33 degrees C, respectively; for group 2 -85 degrees C, -37 degrees C, -2 degrees C, and 25 degrees C; and for group 3 -10 degrees C, -45 degrees C, -20 degrees C, and 6 degrees C. For group 1, the temperature obtained with a double probe at 5, 10, 15, and 20 mm from each probe was -65 degrees C, 0 degrees C, 20 degrees C, and 30 degrees C, respectively; for group 2 -72 degrees C, -25 degrees C, 5 degrees C, 25 degrees C; and for Group 3 -82 degrees C, -30 degrees C, -12 degrees C, 13 degrees C. Complete necrosis was seen 5 mm from the cryoprobe within each group, but only in groups 2 and 3 did necrosis extend 10 mm or beyond the probes when utilizing either single or double probes. The maximum diameter of consistent necrosis was 35 to 40 mm in the animals in group 3 treated with a double probe. Bleeding and renal fracture were the two most common complications. CONCLUSIONS: A 5-minute freeze appears to be inadequate to cause tissue necrosis and is associated with excessive bleeding at the time of the procedure, whereas the 15-minute freeze produces consistent necrosis but is associated with renal fracture. In this animal model, the 10-minute freeze with the single or double probe configuration appears optimal to produce necrosis without complications.

PlasmaKinetic bipolar vessel sealing: burst pressures and thermal spread in an animal model.

BACKGROUND AND PURPOSE: Laparoscopic bipolar instruments are commonly employed to cauterize and divide tissue. A next-generation bipolar device has been developed that employs vapor pulse coagulation energy. We assessed the vessel-sealing capability of this device and quantified thermal spread during application. MATERIALS AND METHODS: Bilateral laparoscopic nephrectomy was performed on six common swine >25 kg. Five-millimeter clips and surgical staplers (US Surgical, Norwalk, CT) were utilized to perform nephrectomy on one side, while the Gyrus PlasmaKinetic bipolar device (Minneapolis, MN) was employed for the contralateral nephrectomy. Vessel-sealing capabilities were assessed via burst-pressure studies. The extent of thermal spread was measured after tissue fixation and hematoxylin and eosin staining. RESULTS: Surgical clips/vascular staplers adequately controlled/sealed renal hilar vessels with burst pressures nearing 300 mm Hg. The Gyrus bipolar device reliably sealed and divided renal arteries

Intraocular Pressure During Robotic-assisted Laparoscopic Procedures Utilizing Steep Trendelenburg Positioning.

PURPOSE: To determine the effect of steep Trendelenburg (sTBURG) surgical positioning on intraocular pressure (IOP) during robotic-assisted laparoscopy (RAL) in subjects without previously identified ocular disease. DESIGN: Prospective cohort study. PARTICIPANTS AND CONTROLS: Eighteen patients undergoing RAL with sTBURG and 21 controls undergoing open and laparoscopic cases in horizontal positioning. MATERIALS AND METHODS: Research data derived from an approved Naval Medical Center, San Diego, CA, IRB protocol. A study group undergoing RAL utilizing sTBURG (group 1) was compared with a control group undergoing open surgery in the horizontal position (group 2), and laparoscopic cases in the horizontal position (group 3). An ophthalmologic examination including Snellen visual acuity, IOP, Humphrey Visual Field (HVF) 24-2 with standard Swedish Interactive Thresholding Algorithm, time domain optical coherence tomography (OCT), retinal nerve fiber layer (RNFL) analysis, pachymetry, and dilated fundus examination was conducted preoperatively and at 1 month postoperatively. IOP was measured intraoperatively at discrete time-points. MAIN OUTCOME MEASURES: IOP values, change in OCT RNFL thickness, HVF mean deviation, and HVF pattern standard deviation. RESULTS: Baseline IOP (mm Hg) was similar, 13.7±3.2 for group 1 versus 15.3±3.2 for group 2 and 14.1±2.4 for group 3 (P=0.55). The IOP plateau from 60 minutes until case conclusion occurred at 29.9 mm Hg (95% confidence interval, 27.4-32.5), 19.9 mm Hg (95% confidence interval, 17.6-22.3), and 22.8 mm Hg (95% confidence interval, 20.2-25.4) for group 1, group 2, and group 3, respectively. There were no significant changes in OCT RNFL thickness, HVF mean deviation, and HVF pattern standard deviation. CONCLUSIONS: Significant elevations of IOP are experienced during robotic surgery utilizing sTBURG positioning in patients with healthy eyes, and we recommend a multidisciplinary approach in determining potential risk to those with known ocular disease who are candidates for these procedures.

Surgical management of urolithiasis.

The surgical management of urinary calculus disease has changed dramatically in the past two decades. Minimally invasive options have made open stone surgery nearly obsolete. The development of shock wave lithotripsy, percutaneous nephrostolithotomy techniques and intracorporeal lithotripsy devices has conferred unprecedented management tools for upper tract stones. Moreover, transfusion rates, hospital costs, and convalescence periods have been markedly reduced when compared to open surgery. Likewise, the advent of fiberoptic technology has resulted in miniaturization of ureteroscopes making access to the entire collecting system possible from either a retrograde or antegrade approach. With experience, successful stone retrieval has occurred in upwards of 90% of cases, again with minimal complications. The subspecialty of Endourology has emerged over the past 20 years and significantly changed the management of urinary tract calculi within this short period of time. Further advancements in shock wave and laser technology, training modules and the development of more durable endoscopes may prove beneficial in providing even better stone treatments with a reduction in morbidity.

Computed tomography urography, three-dimensional computed tomography and virtual endoscopy.

Spiral computed tomography technology allows an entire body region to be imaged as a continuous volume of computed tomography data. The acquisition of genitourinary images can be performed at different intervals after intravenous contrast injection in order to characterize the renal vasculature, the renal parenchyma or the collecting system. Computed tomography scanning as contrast is excreted into the collecting system is termed a 'computed tomography urogram'. Volumetric data from spiral computed tomography can be rendered into conventional two-dimensional images or even reformatted into three-dimensional views of organ systems or hollow structures, as in 'fly-through' virtual endoscopy. Although virtual endoscopy of the urinary tract remains in its infancy, three-dimensional imaging is currently a useful adjunct in the evaluation of renal transplant and donor patients and partial nephrectomy candidates. The role of computed tomography urography compared with intravenous urography in the evaluation of hematuria is discussed.