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Purpose: Improved fiber optics and advanced intracorporeal lithotripsy devices have significantly decreased the incidence of complications during ureteroscopic procedures. Despite recent reports suggesting that radiographic imaging may not be necessary in all individuals after routine ureteroscopy silent obstruction may develop in some, ultimately resulting in renal damage. We determined the incidence of postoperative silent obstruction at our institution and assessed the need for routine functional radiographic studies after ureteroscopy., Materials and Methods: We retrospectively reviewed the charts of 320 patients who underwent a total of 459 ureteroscopic procedures for renal or ureteral calculi in a 3-year period. Complete followup with imaging was available for 241 patients (75%). Average patient age was 47.2 years. The variables of interest reviewed included preoperative pain, preoperative obstruction, targeted calculous site, stone-free rate, postoperative pain and postoperative obstruction. Mean followup was 5.4 months (range 2 to 43)., Results: A total of 241 patients with complete followup were identified in this analysis. Preoperative pain was present in 202 patients (84%) and 168 (70%) had preoperative obstruction. Overall targeted calculous clearance was successful in 73% of the patients and an additional 15.8% had residual fragments less than 4 mm. The renal, proximal or mid and distal ureteral stone-free rate was 32.1%, 81.9% and 90.5%, while in an additional 46.4%, 6.3% and 6.7% of cases, respectively, residual fragments were less than 4 mm. Of the 241 patients 30 (12.3%) had obstruction postoperatively due to residual stone in 25 (83.3%), stricture in 3 (10%), edema of the ureteral orifice in 1 (3.3%) and a retained encrusted stent in 1 (3.3%). Postoperatively obstruction correlated with postoperative pain in 23 of the 30 patients (76.7%). Pain was present postoperatively in 30 of the 211 patients (14%) without evidence of ureteral obstruction postoperatively. However, silent obstruction developed in 7 patients (23.3%) or 2.9% of the total cohort. All 7 patients underwent secondary ureteroscopy to alleviate obstruction. A single patient ultimately received chronic hemodialysis for renal failure, 1 was lost to followup and in 5 there was documented successful resolution of the cause of obstruction., Conclusions: Our analysis suggests that silent obstruction remains a potentially significant complication after stone management. Relying on postoperative pain to determine the necessity of postoperative imaging places patients at risk for progressive renal failure due to unrecognized obstruction. Therefore, we recommend that imaging of the collecting system should be performed by excretory urography, spiral computerized tomography or ultrasound within 3 months after routine ureteroscopic stone treatment to avoid the potential complications of unrecognized ureteral obstruction.

Objectives: A new combination intracorporeal lithotripter (Lithoclast Ultra) has been developed that incorporates the beneficial effects of pneumatic lithotripsy (rapid stone fragmentation) and ultrasound lithotripsy (rapid fragment removal). An in vitro study was performed to assess the efficiency of stone fragmentation and clearance of this new combination intracorporeal lithotripter compared with currently available ultrasound and pneumatic units., Methods: Pneumatic and ultrasound lithotrites, along with the combination pneumatic/ultrasound unit, were used through a rigid 27F nephroscope to fragment and remove phantom stones made of BegoForm. The mean fragment removal times and stone fragment sizes for the standard ultrasound and pneumatic devices were compared with the combination unit to determine the completeness and efficiency of stone fragmentation and removal., Results: The average time for stone clearance using the pneumatic and ultrasound devices was 23.8 and 12.9 minutes, respectively. The combination pneumatic/ultrasound unit was significantly more efficient, requiring only 7.4 minutes to completely fragment and clear all stone material (P <0.002). In addition, the average size of the 15 largest fragments removed was significantly less with the combination device than with the pneumatic and ultrasound lithotrites (1.67 mm versus 9.07 mm and 3.67 mm, respectively, P <0.00001)., Conclusions: The combination of pneumatic and ultrasound capabilities in a newly developed lithotrite exhibited a significantly enhanced ability to fragment and clear phantom stones compared with standard ultrasound or pneumatic devices alone. These preliminary studies suggest that this combination pneumatic/ultrasound lithotripter may be an ideal device for the expeditious removal of large-volume renal or bladder calculi. Additional studies are warranted to better assess the capabilities of this new device in treating human stones of various compositions and its safety, as well as the optimal power and frequency settings.

Objectives: The increased incidental detection of small (less than 4 cm) renal tumors has stimulated investigations of minimally invasive therapies. Radiofrequency energy is a relatively new and evolving technology that has been used for a variety of experimental and clinical applications. We evaluate the efficacy of hypertonic interstitial saline-augmented radiofrequency therapy to ablate a malignant VX-2 tumor implanted in a rabbit kidney, as measured by the completeness of tumor destruction and progression to metastasis., Methods: The VX-2 tumor was surgically implanted into the left lower pole parenchyma of 18 New Zealand white rabbit kidneys. Ten days after implantation, hypertonic interstitial saline-augmented radiofrequency ablation was performed (n = 12) using a radiofrequency therapy system (RFT, United States Surgical Corp.). A sham operation was performed on a control group (n = 6). Animals were humanely killed at 5, 10, and 15-day intervals, and the clinical response and effect of radiofrequency energy on the malignant renal tissue was assessed., Results: No postoperative complications were encountered. The mean size of the implanted VX-2 tumor was 1.87 cm2. Kidneys in the treated group exhibited marked destruction of tumor tissue. Histologic analysis revealed coagulative necrosis of both malignant and normal renal tissue in the treated group. Three rabbits (1 control, 2 treated) died of metastatic disease., Conclusions: Coagulative necrosis of renal parenchyma and tumor tissue was clearly demonstrated after radiofrequency ablation using the RFT system. The aggressive growth pattern of the VX-2 tumor often resulted in progression to metastatic disease while precluding complete tumor ablation. Hypertonic saline-augmented radiofrequency ablation is a promising new technology for the management of small, locally confined, renal tumors and has the potential for use with a minimally invasive approach.

Ureteral stents have assisted urologists in the performance of surgery of the urinary tract for many years. They can have both diagnostic and therapeutic value, but are used most frequently as adjuncts to endoscopic or minimally invasive procedures. This review provides an update of the current uses for ureteral stents, technology of biomaterials, complications associated with indwelling ureteral stents and the future of stents in urology.

Using an experimental system that mimics stone fragmentation in the renal pelvis, we have investigated the role of stress waves and cavitation in stone comminution in shock-wave lithotripsy (SWL). Spherical plaster-of-Paris stone phantoms (D = 10 mm) were exposed to 25, 50, 100, 200, 300 and 500 shocks at the beam focus of a Dornier HM-3 lithotripter operated at 20 kV and a pulse repetition rate of 1 Hz. The stone phantoms were immersed either in degassed water or in castor oil to delineate the contribution of stress waves and cavitation to stone comminution. It was found that, while in degassed water there is a progressive disintegration of the stone phantoms into small pieces, the fragments produced in castor oil are fairly sizable. From 25 to 500 shocks, clinically passable fragments (< 2 mm) produced in degassed water increases from 3% to 66%, whereas, in castor oil, the corresponding values are from 2% to 11%. Similar observations were confirmed using kidney stones with a primary composition of calcium oxalate monohydrate. After 200 shocks, 89% of the fragments of the kidney stones treated in degassed water became passable, but only 22% of the fragments of the kidney stones treated in castor oil were less than 2 mm in size. This apparent size limitation of the stone fragments produced primarily by stress waves (in castor oil) is likely caused by the destructive superposition of the stress waves reverberating inside the fragments, when their sizes are less than half of the compressive wavelength in the stone material. On the other hand, if a stone is only exposed to cavitation bubbles induced in SWL, the resultant fragmentation is much less effective than that produced by the combination of stress waves and cavitation. It is concluded that, although stress wave-induced fracture is important for the initial disintegration of kidney stones, cavitation is necessary to produce fine passable fragments, which are most critical for the success of clinical SWL. Stress waves and cavitation work synergistically, rather than independently, to produce effective and successful disintegration of renal calculi in SWL

Purpose: Direct percutaneous access provides effective treatment for complex caliceal diverticula. Yet, access into the diverticulum alone is usually tenuous and passage of a guide wire across a stenotic infundibulum is often impossible. An alternative technique is described which creates a "neoinfundibulum" to assist in the management of symptomatic caliceal diverticula., Materials and Methods: During a 6-year period 22 patients with symptomatic caliceal diverticula were treated via a percutaneous approach, of whom 21 had calculi within the diverticula. After accessing the diverticulum directly, it was impossible to pass a guide wire through the stenotic infundibulum in 18 (82%) patients, prompting advancement of the access needle through the diverticular wall into the renal pelvis. Once secure access was established, balloon dilation was performed to 30Fr to create the "neoinfundibulum." Percutaneous ultrasonic lithotripsy was performed in the usual fashion. A 22Fr Councill catheter was placed to keep the infundibular tract open for 5 to 7 days to allow complete epithelialization and drainage. Stone-free, symptom-free and complication rates were assessed., Results: Pain, recurrent urinary tract infections and hematuria were the presenting complaints in the subgroup of patients undergoing "neoinfundibulotomy." Average stone burden was 11.7 x 12 mm. and average hospital stay was 2.8 days. Of the patients 94% were symptom-free at 6-week followup, and 80% were stone-free on followup excretory urography. The remaining patients had residual stone fragments less than 3 mm. in diameter. Complications related to access were identified in 2 patients who sustained a pneumothorax after a supra-11th rib access, which was successfully managed with tube thoracostomy., Conclusions: Percutaneous management of complex caliceal diverticula provides a safe and effective option for symptomatic patients. When the stenotic infundibulum cannot be traversed with a guide wire, creation of a new infundibulum offers a secure alternative for accessing the collecting system, while providing equally effective results.

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.

Background and Purpose: Retrospective studies have suggested that routine stenting can be avoided following ureteroscopy. We prospectively analyzed the need for routine ureteral stent placement in patients undergoing ureteroscopic procedures., Patients and Methods: Fifty-five consecutive patients (60 renal units) were randomized into either a stent or a no-stent group following ureteroscopy with either a 7.5F semirigid or a 7.5F flexible ureteroscope for treatment of calculi (holmium laser or pneumatic lithotripsy) or transitional-cell carcinoma (holmium laser). Intraoperative variables assessed included total stone burden, the need for ureteral dilation, and overall operative times. All patients were evaluated by questionnaire on postoperative days 0, 1, and 6 with regard to pain, frequency, urgency, dysuria, and hematuria., Results: Of the 60 renal units treated, 38 received ureteral stents (mean 5.2 days), and 22 were treated without a stent. All 10 patients requiring ureteral balloon dilation had stents placed and were removed from the analysis. There was no significant difference between the groups with regard to age, sex, or stone burden. Operative time was decreased in the no-stent group (43 minutes v 55 minutes; P = 0.013). Flank discomfort was significantly less common in the no-stent group on days 0, 1, and 6 (P = 0.004, P = 0.003, P < 0.001, respectively), as was the incidence of suprapubic pain on day 6 (P = 0.002). There was no difference in urinary frequency, urgency, or dysuria between the groups on postoperative day 1, but all these symptoms were significantly reduced in the no-stent group on day 6 (P < 0.001, P < 0.001, P = 0.002, respectively). There was no significant difference in patient-reported postoperative hematuria in either group. One patient in each group developed a urinary tract infection. One patient in the no-stent group developed ureteral obstruction in the postoperative period that necessitated stenting, and one patient in the stent group experienced stent migration necessitating removal., Conclusions: Routine ureteral stenting does not appear to be warranted in those patients who do not require ureteral dilation during ureteroscopic procedures. Ureteral stent placement following ureteroscopy may be avoided, thereby reducing operative time, surgical costs, and patient morbidity.

Purpose: Shock wave lithotripsy is believed to cause renal damage directly through cellular injury from high energy shock waves and indirectly through vascular injury and resultant ischemia, which gives rise to oxygen free radical compounds. The transient and volatile nature of free radicals and derived products makes their detection difficult. Moreover, certain medications may provide a protective effect against shock wave lithotripsy induced renal parenchymal injury. We introduced an innovative microdialysis system for in vivo sampling of interstitial fluids that can be analyzed for free radical mediated lipid peroxidation products after shock wave lithotripsy treatment in the swine model. In addition, this system was used to test the antioxidant or renoprotective action of allopurinol., Materials and Methods: Ten juvenile swine were assigned to a nonmedicated control group that underwent shock wave lithotripsy or to a group that was premedicated with allopurinol before shock wave lithotripsy. Each group of animals underwent shock wave lithotripsy to the lower pole of the right kidney and received a total of 10,000 shock waves. Dialysate fluid was collected at 1,000-shock wave increments via probes surgically implanted into the lower pole of the right and left kidneys before lithotripsy. Samples were immediately preserved in liquid nitrogen and subsequently analyzed for the presence and concentration of conjugated diene levels, a measure of lipid peroxidation. Five additional juvenile swine were assigned to a sham treated group that did not undergo shock wave lithotripsy. Dialysate fluid was collected from the lower pole of the right and left kidneys to establish baseline or pre-lithotripsy levels of conjugated dienes., Results: After shock wave lithotripsy conjugated diene levels increased almost 100-fold over that in the right kidneys of the nonmedicated control group. The difference was statistically significant compared to levels in the contralateral untreated kidneys (p <0.01). Right kidneys in the group premedicated with allopurinol did not demonstrate an increase in conjugated diene levels during shock wave lithotripsy., Conclusions: The results of this study confirm shock wave lithotripsy induced free radical activity as well the antioxidant and protective nature of allopurinol. The newly described microdialysis system enables real-time sampling of interstitial fluids during shock wave lithotripsy. It represents a unique method for assessing free radical formation and evaluating the protective effects of additional antioxidant medications.

Purpose: The efficacy of shock wave lithotripsy and percutaneous stone removal for the treatment of symptomatic lower pole renal calculi was determined., Materials and Methods: A prospective randomized, multicenter clinical trial was performed comparing shock wave lithotripsy and percutaneous stone removal for symptomatic lower pole only renal calculi 30 mm. or less., Results: Of 128 patients enrolled in the study 60 with a mean stone size of 14.43 mm. were randomized to percutaneous stone removal (58 treated, 2 awaiting treatment) and 68 with a mean stone size of 14.03 mm. were randomized to shock wave lithotripsy (64 treated, 4 awaiting treatment). Followup at 3 months was available for 88% of treated patients. The 3-month postoperative stone-free rates overall were 95% for percutaneous removal versus 37% lithotripsy (p <0.001). Shock wave lithotripsy results varied inversely with stone burden while percutaneous stone-free rates were independent of stone burden. Stone clearance from the lower pole following shock wave lithotripsy was particularly problematic for calculi greater than 10 mm. in diameter with only 7 of 33 (21%) patients becoming stone-free. Re-treatment was necessary in 10 (16%) lithotripsy and 5 (9%) percutaneous cases. There were 9 treatment failures in the lithotripsy group and none in the percutaneous group. Ancillary treatment was necessary in 13% of lithotripsy and 2% percutaneous cases. Morbidity was low overall and did not differ significantly between the groups (percutaneous stone removal 22%, shock wave lithotripsy 11%, p =0.087). In the shock wave lithotripsy group there was no difference in lower pole anatomical measurements between kidneys in which complete stone clearance did or did not occur., Conclusions: Stone clearance from the lower pole following shock wave lithotripsy is poor, especially for stones greater than 10 mm. in diameter. Calculi greater than 10 mm. in diameter are better managed initially with percutaneous removal due to its high degree of efficacy and acceptably low morbidity.

Purpose: Percutaneous renal surgery is currently performed for complex renal calculi as well as for various other endourological indications. In many patients an upper pole nephrostomy tract allows direct access to most of the intrarenal collecting system. Upper pole percutaneous access may be obtained via the supracostal or subcostal approach. The preferred route depends on the location and size of the specific stone or lesion. Previously others have cautioned against the supracostal approach above the 12th rib and many have discouraged an approach above the 11th rib due to concern about the increased risk of intrathoracic complications. We retrospectively assessed the morbidity associated with supracostal percutaneous renal surgery and compared and analyzed the morbidity of the supracostal and subcostal approaches., Materials and Methods: The records of all patients who underwent upper pole percutaneous renal surgery between November 1993 and July 1999 were retrospectively reviewed. A total of 240 patients underwent percutaneous renal procedures, including 225 for managing symptomatic renal or ureteral stones, that is nonstaghorn calculi in 157, staghorn calculi in 41, proximal ureteral calculi in 12, calculi within a caliceal diverticulum in 6, calculi associated with primary ureteropelvic junction obstruction in 5 and calculi associated with a retained ureteral stent in 4. An additional 15 procedures were done for ureteropelvic junction obstruction (7), intrarenal collecting system tumors (5), a caliceal diverticulum without stones (1), a retained ureteral stent (1) and a ureteral stricture (1)., Results: A total of 300 nephrostomy tracts were placed to obtain access to the intrarenal collecting system via the supracostal approach in 98 (32.7%) cases and the subcostal approach in 202 (67.3%). Of the supracostal approaches 72 (73.5%) tracts were above the 12th and 26 (26.5%) were above the 11th rib. The overall complication rate irrespective of percutaneous approach was 8.3% (16.3% for supracostal and 4.5% for subcostal access). Complications included blood transfusion in 7 patients, intraoperative hemothorax/hydrothorax in 5, sepsis/bacteremia in 3, atrial fibrillation in 2, delayed nephropleural fistula in 2, renal artery pseudoaneurysm in 2, deep venous thrombosis/pulmonary embolus in 2, pneumothorax in 1 and subcapsular hematoma in 1. Seven of 8 intrathoracic complications (87.5%) developed in supracostal cases., Conclusions: Percutaneous renal surgery remains an important option for managing complex renal calculi and other upper urinary tract lesions. In our experience it is generally associated with low morbidity. The supracostal approach is often preferred for obtaining intrarenal access to complex renal and proximal ureteral pathology. Because supracostal access tracts are associated with significantly higher intrathoracic and overall complication rates compared to subcostal access tracts, this approach must be used with caution when no other alternatives are available.

Purpose: We review our technique of ureteroscopic management of lower pole renal calculi with Nitinol basket displacement and holmium laser stone fragmentation., Methods: Lower pole calculi are identified with a 7.5F flexible ureteroscope. In patients in whom the laser fiber reduces ureteroscopic deflection, precluding reentry into the lower pole, a Nitinol basket or grasper is used to displace the calculi into an upper pole calix for easier fragmentation., Results: The Nitinol device can be passed into the lower pole through the fully deflected ureteroscope without any loss of deflection. Irrigation is significantly reduced by the basket, but this factor does not impede stone retrieval., Conclusions: Ureteroscopic management of lower pole stones is a reasonable alternative to SWL or percutaneous nephrolithotomy in low-volume stone disease. If the stone cannot be fragmented in situ, Nitinol basket capture through a fully deflected ureteroscope into a less dependent position facilitates stone fragmentation.

Purpose: When using a ureteral access sheath following a ureteroscopic procedure, placement of an internal ureteral stent can be simplified by inserting the stent through the sheath without the need to reinsert the cystoscope., Materials and Methods: An indwelling ureteral stent with the pull string attached is inserted over the guide wire into the access sheath followed by the pusher. The guide wire is partially withdrawn allowing the stent to form a coil in the renal pelvis, using the pull string to adjust the stent position. The fluoroscopy unit is then focused onto the bladder and the guide wire is slowly withdrawn until its tip is at the level of pubic symphysis. The pusher and guide wire are then removed and the pull string is cut at the urethral meatus., Results: Among 71 cases studied 60 required ureteral stent placement. In 43 of the 60 cases (72%) the ureteral access sheath greatly facilitated ureteroscopy, and a stent was placed through the access sheath in 34 (79%). Stent placement through the access sheath was successful in all cases, with an average time saving of 2.3 minutes per case, compared to placing the stent by reinserting a cystoscope., Conclusions: If an access sheath has already been placed during a ureteroscopic procedure and stent insertion is deemed necessary, the stent can be easily placed through the access sheath under fluoroscopic guidance without the need to reinsert the cystoscope. Our experience suggests that all urologists who routinely perform ureteroscopic procedures can easily master this timesaving technique.

Background and Purpose: Introduction of the holmium laser has provided an indispensable tool for the management of urinary tract stones, strictures, and superficial urothelial tumors. While full-power holmium lasers are required for laser resection of the prostate, lower-power devices can be utilized for all cases of stone fragmentation and stricture incision and most cases of superficial urothelial tumors. Herein, we report our initial experience in utilizing a low-power holmium laser in our endourologic practice., Patients and Methods: Over a 6-month period, we have utilized both low-power (25 W) and full-power (80 W) holmium lasers to fragment urinary tract stones, incise ureteral or urethral strictures, and ablate superficial urothelial tumors. A series of 80 consecutive patients were assessed prospectively. Laser fibers with a diameter of 200 microm and 365 microm were employed with power settings of 6.4 to 10 W. Laser fiber size and power settings were similar for the low- and full-power devices., Results: Overall, 95% of the stones were completely fragmented, with a stone-free rate at 3 months of 92%. All strictures were incised, with a 91% patency rate at 3 months. Complete tumor ablation was attained in 70%, with a tumor-free rate of 60% at 3 months. Results were equivalent for the low- and full-power lasers. The 200-microm laser fiber allowed adequate access throughout the upper urinary tract during flexible ureteroscopy and flexible nephroscopy. The 365-microm laser fiber was employed via rigid and semirigid endoscopes., Conclusions: A low-power holmium laser supplies adequate fragmentation and incision power for virtually all endourologic cases. It also provides ablative power in most situations. The only current urologic application that cannot be performed with the low-power device is laser prostatic resection, which requires 60 to 80 W of power. The reduced-power holmium laser should be considered as a low-cost alternative for the management of urinary tract stones, strictures, and urothelial tumors, especially in centers where laser prostatic resection is not performed.

Objectives: To examine personal financial management among residents to answer three research questions: do residents make reasonable financial choices; why do some residents not save; and what steps can be taken to improve residents' personal financial decisions., Methods: Portions of the Federal Reserve Board's Survey of Consumer Finances were modified and piloted to elicit demographic, expense, saving, and income data. The final questionnaire was completed by 151 urology residents at 20 programs., Results: Comparing residents with the general population in the same age and income categories, the median debt/household income ratio was 2.38 versus 0.64. Residents had greater educational debt, greater noneducational debt, and lower savings. Resident participation in retirement accounts was 100% at institutions with employer-matching 401k or 403b plans, 63% at institutions with nonmatching 401k or 403b plans, and 48% at institutions without retirement plans for residents (P = 0.002). Fifty-nine percent of residents budgeted expenses, 27% had cash balances below $1000, 51% had paid interest charges on credit cards within the previous year, and 12% maintained unpaid credit card balances greater than $10,000. The median resident income was $38,400., Conclusions: A significant minority of residents appear not to make reasonable financial choices. Some residents save little because of a failure to budget, indebtedness, high projected income growth, or insufficient attention to personal financial management. Residents save more when they are eligible for tax-deferred retirement plans, particularly when their institution matches their contributions. Many residents would benefit from instruction concerning prudent financial management.

Background and Purpose: Comprehensive metabolic evaluation has become an important aspect of the management of recurrent nephrolithiasis, yet the role of stone analysis is often neglected or perhaps underestimated. The purpose of this study was to determine the role of stone analysis in medical decision making in patients with recurrent nephrolithiasis., Materials and Methods: We evaluated 100 consecutive stone-forming patients who had undergone compositional stone analysis as well as comprehensive metabolic evaluation at our institution. An analysis of stone composition in relation to metabolic disturbances was performed. Patients were stratified into two groups: calcium and non-calcium stone formers., Results: Patients having non-calcium stones were found to have a metabolic analysis reflecting specific metabolic disorders. Alternatively, patients with calcium stones were heterogeneous with regard to metabolic disorders, but there was a significant likelihood of renal tubular acidosis in those patients with calcium phosphate calculi. On the basis of these results, a simplified metabolic evaluation and nonselective medical therapy based on stone composition was formulated to facilitate assessment, management, and monitoring of stone disease., Conclusions: Compositional stone analysis should be an integral part of the metabolic evaluation of patients with nephrolithiasis. Moreover, stone analysis alone may provide guidance for therapeutic treatment and obviate a formal metabolic evaluation.

Purpose: Ureteral access sheaths were initially developed to facilitate difficult ureteroscopic access. However, to our knowledge no formal evaluations have been performed to assess the routine use of ureteral access sheaths. Therefore, we prospectively analyzed intraoperative time, symptomatic outcome, major complications, stone-free rate and overall costs related to the routine use of a new ureteral access sheath during standard ureteroscopic procedures., Materials and Methods: Patients undergoing 6.5Fr semirigid or 7.5Fr flexible ureteroscopy were prospectively randomized to unaided ureteroscopy with no access sheath or ureteroscopy via a 12-14Fr ureteral access sheath. Patients who required ureteral dilatation were randomized to the ureteral access sheath used as a dilator or a standard 18Fr ureteral balloon dilator. Patients were evaluated postoperatively on days 0, 1 and 6 with a questionnaire to assess pain, irritative symptoms and complications. The stone-free rate and long-term complications were determined by excretory urography or computerized tomography at 3 months., Results: Enrolled in the study were 59 consecutive patients, who underwent a total of 62 ureteroscopic procedures. Of the 47 patients (76%) who did not require ureteral dilatation 23 (49%) underwent ureteroscopy via the ureteral access sheath and 24 (51%) underwent unaided ureteroscopy. Seven of the 15 patients (28%) who required ureteral dilatation underwent access sheath dilatation, while balloon dilatation was performed in 8. There was no significant difference in postoperative symptoms, complication rate or stone-free status in the access sheath and nonaccess sheath groups in patients not requiring ureteral dilatation (p <0.05). A significant increase in postoperative symptoms was noted when the balloon was used as a dilator compared to the access sheath. Operative time and costs in all patients who underwent access sheath dilatation were less than in those in whom the access sheath was not used. In the 15 patients who required dilatation 71% of access sheath and 100% of balloon dilatations were successful., Conclusions: Routine use of a ureteral access sheath appears to facilitate semirigid and flexible ureteroscopy by decreasing operative time and costs, allowing direct visualization of ureteroscope insertion with simple ureteral re-entry and assisting renal and ureteral access with minimal associated morbidity. A ureteral access sheath should be considered for routine ureteroscopic procedures.

One of the most significant developments in imaging technology has been the process of digitalization. By incorporating currently available digital imaging equipment into surgical practice, urologists can be assured of obtaining real-time video images with optimal clarity and detail. In addition, one can efficiently capture and store still images that are crisper and sharper than their analog counterparts. These factors greatly improve the diagnostic capabilities and organization of today's endourologist.

Telemedicine, or the delivery of health care from a distance, is an exciting field that has undergone rapid advancements over the past three decades. Previous studies have demonstrated that telemedicine can effectively assist in patient care. However, cost issues and the lack of resources to sustain telemedicine systems have previously limited the use of this technology. Herein, we explore the development, current applications, and future of telemedicine.

The introduction of technological advances, such as HDTV, three-dimensional laparoscopy, and further miniaturization of high-resolution digital video cameras, will allow significantly enhanced opportunities for laparoscopic surgical proficiency and further broadening of laparoscopic applications in urology. These enhancements, coupled with the recent advances in telemedicine and surgical simulation, will improve laparoscopic training and skill acquisition, decrease operative times and costs, minimize morbidity, and improve overall patient care.

The concept of virtual reality (VR) involves the computer generation of environments with which a user can interact directly. Virtual reality is now being used for medical applications, especially in the area of surgical simulation. As technology advances, VR simulation will play an important training role for both residents and urologists already in practice. This paper examines the history of VR, current developments, and its future implications for the field of urology.

Objectives: Current ureteroscopic intracorporeal lithotripsy devices and stone retrieval technology allow for the treatment of calculi located throughout the intrarenal collecting system. Difficulty accessing lower pole calculi, especially when the holmium laser fiber is used, is often encountered. We retrospectively reviewed our experience with cases in which lower pole renal calculi were ureteroscopically managed by holmium laser fragmentation, either in situ or by first displacing the stone into a less dependent position with the aid of a nitinol stone retrieval device., Methods: Thirty-four patients (36 renal units) underwent ureteroscopic treatment of lower pole renal calculi between April 1998 and November 1999. Lower pole stones less than 20 mm were primarily treated by ureteroscopic means in patients who were obese, in patients who had a bleeding diathesis, in patients with stones resistant to shock wave lithotripsy, and in patients with complicated intrarenal anatomy, or as a salvage procedure after failed shock wave lithotripsy. Lower pole calculi were fragmented with a 200-micrometer holmium laser fiber by way of a 7.5F flexible ureteroscope. For those patients in whom the laser fiber reduced the ureteroscopic deflection, precluding re-entry into the lower pole calix, a 3.2F nitinol basket or a 2.6F nitinol grasper was used to displace the lower pole calculus into a more favorable position, allowing easier fragmentation., Results: In 26 renal units, routine in situ holmium laser fragmentation was successfully performed. In the remaining 10 renal units, a nitinol device was passed into the lower pole, through the ureteroscope, for stone displacement. Only a minimal loss of deflection was seen. Irrigation was significantly reduced by the 3.2F nitinol basket, but improved with the use of the 2.6F nitinol grasper. This factor did not impede stone retrieval in any of the patients. At 3 months, 85% of patients were stone free by intravenous urography or computed tomography., Conclusions: Ureteroscopic management of lower pole calculi is a reasonable alternative to shock wave lithotripsy or percutaneous nephrolithotomy in patients with low-volume stone disease. If the stone cannot be fragmented in situ, nitinol basket or grasper retrieval, through a fully deflected ureteroscope, allows one to reposition the stone into a less dependent position, thus facilitating stone fragmentation.

Purpose: We developed an optical system to quantify in vitro tip movement of the Lithoclastdouble dagger flexible probe, and correlated various physical parameters of the vibrating probe tip with resultant stone fragmentation., Materials and Methods: A noncontact optical measurement system was developed to quantify in vitro tip movement of the Lithoclast flexible probe. This system and an in vitro fragmentation model were used to determine the tip displacement, velocity, impact momentum, impact energy and stone fragmentation of the flexible probe at 5 deflection angles between 0 and 48 degrees, and the 2 pneumatic pressure levels of 2.0 and 2.5 bar., Results: An increase in maximum probe tip displacement, velocity, impact momentum and energy, and stone fragmentation was seen as the pneumatic pressure was increased from 2.0 to 2.5 bar. A progressive decrease in these parameters was demonstrated as the probe tip was deflected, especially at deflection angles greater than 24 degrees. Impact momentum appears to be the physical parameter most closely correlated with stone fragmentation efficiency., Conclusions: The optical measurement system and in vitro fragmentation model developed allow one to quickly and reliably assess the performance of flexible pneumatic probes in vitro. This system can be used for general bench testing and basic research that can provide critical information for the design of more effective and efficient flexible pneumatic lithotripsy probes.

Although the true incidence of ureteropelvic junction (UPJ) obstruction in the lower-pole moiety of an incompletely duplicated renal collecting system remains elusive, the description of this entity in the published literature is exceedingly rare. To our knowledge, we report the first case of this entity managed successfully by ureteroscopic holmium laser incision of the stenotic UPJ segment. This case underscores the utility of minimally invasive techniques in the management of selected cases of UPJ obstruction associated with a partially duplicated collecting system.

In the not too distant future, the minimally invasive renal surgeon will be able to practice an operation on a difficult case on a three-dimensional virtual reality simulator, providing all attributes of the real procedure. The patient's imaging studies will be imported into the simulator to better mimic particular anatomy. When confident enough of his or her skills, the surgeon will start operating on the patient using the same virtual reality simulator/telepresence surgery console system, which will permit the live surgery to be conducted by robots hundreds of miles away. The robots will manipulate miniature endoscopes or control minimally or noninvasive ablative technologies. Endoscopic/laparoscopic footage of the surgical procedure will be stored digitally in optical disks to be used later in telementoring of a surgery resident. All this and more will be possible in the not so distant third millennium.

Objectives: Shock wave lithotripsy (SWL) is the primary treatment modality for managing the majority of symptomatic renal calculi. However, the fundamental mechanisms for stone fragmentation and the resultant morphologic changes that occur are not fully understood. Furthermore, a thorough understanding of the complex biologic pathways involved in SWL-induced renal injury does not exist at present. To elucidate the biologic processes involved in tissue injury after SWL, an animal model was designed to mimic the pathogenesis of high-energy SWL in humans., Methods: Juvenile female swine were anesthetized, and a midline laparotomy incision was performed to expose the right kidney. Using an introducer apparatus, a microdialysis probe was placed into the renal parenchyma of the right kidney lower pole and a tunnel was generated to exit the distal ends of the inlet and outlet tubing outside the body. After a 72-hour postoperative recovery period, SWL was performed to the lower pole renal region of the kidney, as a microdialysis pump continuously infused dialysate through the inlet tubing. Microdialysis fluids were collected during SWL, and lipid peroxidation, as measured by conjugated diene concentrations, was monitored., Results: All microdialysis probes remained patent for a total of 2000 shock waves. A significant elevation in conjugated diene levels was observed in the SWL versus untreated kidneys after 1000 shock waves were administered (P <0.02)., Conclusions: This animal model is unique in that it represents the first system for the real-time collection of renal interstitial fluids during SWL. Analysis of this fluid may provide insight into the physiologic mechanisms responsible for shock wave-induced renal injury.

Purpose: Standardized and reproducible artificial kidney stone models are important for performing comparative studies of different lithotripsy modalities. The acoustic and mechanical properties of renal calculi dictate the manner by which stones interact with the mechanical stresses produced by shock wave lithotripsy (SWL) or intracorporeal lithotripsy modalities. We have developed a novel artificial kidney stone model that is made of natural substances found in real kidney stones. These stone models appear to be much closer in physical properties to natural kidney stones than previously used stone models., Materials and Methods: The acoustic and mechanical properties of six groups of artificial stone models were compared to corresponding natural stones of similar compositions. Moreover, three groups of artificial stone models made of plaster-of-Paris were compared to their natural counterparts. In terms of acoustic properties, stone density was measured using a pycnometer based on Archimedes' principle, whereas longitudinal and transverse (or shear) wave propagation speeds were measured using an ultrasound pulse transmission technique. These values were used to calculate wave impedance and dynamic mechanical properties (bulk modulus, Young's modulus, and shear modulus) of the stones. The microhardness of the stones was measured and the effect of composition on stone fragility was evaluated., Results: Artificial stones, when compared to natural stones of similar composition, showed similar trends in longitudinal and transverse wave speeds, wave impedance, and dynamic elastic moduli. However, values for the artificial stones were uniformly low compared to those of natural stones, suggesting that these artificial stones may be more amenable to shock wave fragmentation. The results of SWL on stone fragmentation of artificial and natural stones also revealed similar trends with the exception of artificial cystine stones which were found to be the most resistant to shock wave fragmentation., Conclusions: The results indicate that the physical properties of artificial stones made of natural stone materials are comparable to renal calculi of the same chemical composition. The data suggests that these stone phantoms are suitable for performing standardized and reproducible in vitro investigations, especially with regards to fragility of kidney stones of different chemical compositions during SWL.

Background and Purpose: Patients with recurrent cystine nephrolithiasis oftentimes require multiple procedures for stone removal. As the majority of cystine stones are resistant to the effects of shockwave lithotripsy, repeat percutaneous surgery is often required and may cause renal damage. Moreover, repeat percutaneous access may become more difficult as perinephric fibrosis develops. Small-caliber ureteroscopes along with the holmium laser now enable routine intrarenal ureteroscopic access to symptomatic renal stones. Herein, we present our experience in managing recurrent renal cystine calculi using flexible ureterorenoscopy and assess whether such an approach may be used as an alternative to percutaneous surgery in selected patients., Patients and Methods: Three patients with large-volume (mean diameter 22 mm) renal cystine stones were managed with a 7.5F flexible ureterorenoscope combined with holmium laser lithotripsy to fragment the stones completely., Results: The mean treatment time was 97 minutes, with successful fragmentation in all cases. Two of the three patients were completely stone free on follow-up intravenous urography, with the third patient having only small-volume residual fragments in a lower pole calix. All patients are currently asymptomatic and are being maintained on high oral fluid intake, urinary alkalization with potassium citrate, and alpha-mercaptopropionylglycine to reduce urinary cystine excretion., Conclusion: Flexible ureterorenoscopy with holmium laser lithotripsy provides a reasonable alternative for the management for recurrent cystine calculi in patients who are not candidates for repeat percutaneous procedures. Although it is time consuming, complete stone fragmentation, along with clearance of fragments, can be achieved in the majority of patients.

Purpose: Pneumatic lithotripsy has proved to be an extremely safe, efficient and low cost intracorporeal fragmentation modality. Unfortunately proximal migration of fragments into inaccessible areas in the intrarenal collecting system is a potential limitation during ureteroscopic procedures. Moreover, the lack of an efficient mechanism of stone retrieval further limits the widespread application of this technique. The newly developed Lithovacdagger suction device was designed to be combined with pneumatic lithotripsy during ureteroscopic stone removal. We evaluated the effectiveness of this combination for overcoming these limitations., Materials and Methods: Between February and December 1998, 21 patients underwent pneumatic lithotripsy of ureteral calculi combined with use of the Lithovac suction probe. Stone area was 20 to 320 mm.2 (mean 84). Of the stones 71% and 29% were in the distal, and proximal and/or mid ureter, respectively. We used a 0.8 mm. pneumatic lithotripsy probe placed through a 4.8Fr Lithovac probe at a pulse frequency of 12 Hz. and pressure of 2 atmospheres., Results: Mean operative time was 42 minutes and the stone fragmentation rate was 100%. There were no complications in our series and no proximal migration of fragments. The overall stone-free rate was 95% at 3-month followup., Conclusions: Using the Lithovac suction device greatly facilitates pneumatic lithotripsy during ureteroscopic stone removal. This combination not only prevents fragment migration, but also aids in maintaining a clear endoscopic field of view, allowing efficient, safe and effective stone fragmentation.

The efficiency and safety profile of the holmium laser have made this tool a versatile multipurpose instrument for use in the endoscopic treatment of a wide variety of urologic disorders. Herein are reviewed holmium laser physics and current endourologic applications, as well as the performance of new low-power holmium lasers.

Stone-free status is highly dependent on selection of the appropriate surgical technique, which should be tailored according to the individual stone and patient parameters. Although a stone-free state is the desired outcome of surgical intervention of urolithiasis, the authors believe that the presence of noninfection, nonobstructive, asymptomatic postprocedural residual fragments can be managed metabolically in order to prevent stone growth adequately. Further surgical intervention in the case of residual fragments is warranted if the clinical indications that prompted the original surgery persist.

Background: Endourologic management of stones and strictures in patients with a urinary diversion is often cumbersome because of the absence of standard anatomic landmarks. We report on our technique of minimally invasive management of urinary diversion-associated pathology by means of a combined antegrade and retrograde approach., Patients and Methods: Five patients with urinary diversion-associated pathology were treated at our institution between May 1997 and October 1998. Their problems were: an obstructing ureteral stone in a man with ureterosigmoidostomy performed for bladder extrophy; two men with a valve stricture in their hemiKock urinary diversions; an anastomotic stricture in a man with an ileal loop diversion; and a long left ureteroenteric stricture in a man with a right colon pouch diversion. After percutaneous placement of an guidewire across the area of interest, the targeted pathology was accessed via a retrograde approach using standard semirigid or flexible fiberoptic endoscopes. Postoperative follow-up with intravenous urography, differential renal scan, or both was performed at 3 to 24 months (mean 12 months)., Results: The combined antegrade and retrograde approach allowed successful access to pathologic areas in all patients. Holmium laser/Acucise incision of stenotic segments or ballistic fragmentation of stones was achieved in all cases without perioperative complications. None of the strictures with an initially successful outcome has recurred; however, in one patient, the procedure failed as soon as the internal stent was removed. The patient with the ureteral calculus remains stone free, and his ureterosigmoidostomy is patent without evidence of obstruction on his last imaging study, 24 months postoperatively., Conclusions: Combined antegrade and retrograde endoscopic access to the area of interest is our preferred method of approaching pathologic problems in patients with a urinary diversion. An antegrade nephrostogram provides better delineation of anatomy, while through-and-through access enables rapid and easier identification of stenotic segments that may be hidden by mucosal folds. Furthermore, this approach allows the use of larger semirigid or flexible endoscopes in conjunction with more efficient fragmentation devices, resulting in enhanced vision from better irrigation. Finally, an initial endoscopic approach may be preferred because its failure does not compromise the success of future open surgery.

Purpose: Patient preferences, or utilities, may be crucial to select an appropriate treatment plan for stone disease. We used decision modeling to understand better patient choices and decision making in the overall management of recurrent nephrolithiasis., Materials and Methods: We interviewed 180 consecutive patients with active stone disease. Demographic data and historical experiences with calculi were recorded. Patients were presented with 6 hypothetical clinical scenarios and various treatment options. The standard gamble method was used to obtain utility values for each option., Results: Nephrectomy had the lowest mean utility value of 0.883. Percutaneous nephrolithotomy for severe, moderate and mild pain had utilities of 0.924, 0.932 and 0.947, respectively. Shock wave lithotripsy for the management of mild pain was the most attractive option (mean utility 0.968). The utility for long-term medical therapy was 0.949, which was between that of percutaneous nephrolithotomy and shock wave lithotripsy for mild pain. Patients with a surgical history of stone removal assigned lower utilities to invasive procedures (nephrectomy, percutaneous nephrolithotomy, p <0.05). As the incidence of spontaneous stone passage increased, a higher utility was given to long-term medical therapy (p <0.05). Patients on medical therapy less than 1 year did not appreciate a significant benefit of medical prophylaxis. However, longer compliance with medical management led patients to perceive increasing benefits of continuing such medical treatment (p <0.05). Patients who had undergone stone removal via endoscopic or open surgery also had a higher preference for medical therapy (p <0.05)., Conclusions: Patients who had undergone stone removal wanted to avoid future invasive procedures. They ranked long-term medical therapy below shock wave lithotripsy but above invasive procedures, such as percutaneous nephrolithotomy. Most importantly, patients appreciated the benefits of medical therapy the longer that they complied with specific recommendations. These results support the concept that patients perceive long-term medical therapy to prevent recurrent nephrolithiasis as a desirable treatment option.

Two projects in our laboratory highlight some recent developments in shockwave lithotripsy (SWL) physics research. In the first project, we developed a prototype of a piezoelectric annular array (PEAA) shockwave generator that can be retrofitted on a Dornier HM-3 lithotripter for active control of cavitation during SWL. The PEAA generator, operating at 15 kV, produces a peak positive pressure of approximately 8 MPa with a -6-dB beam diameter of 5 mm. The shockwave generated by the PEAA was used to control and force the collapse of cavitation bubbles induced by a laboratory electrohydraulic shockwave lithotripter with a truncated HM-3 reflector. With optimal time delay between the lithotripter pulse and the PEAA-generated shockwave, the collapse of cavitation bubbles near the stone surface could be intensified, and the resultant stone fragmentation in vitro could be significantly improved. In the second project, high-speed shadowgraph imaging was used to visualize the dynamics of lithotripter-induced bubble oscillation in a vascular phantom. Compared with the free bubble oscillation in water, the expansion of cavitation bubble(s) produced in silicone tubes and a 200-microm cellulose hollow fiber by either a Nortech EHL or a Dornier XL-1 lithotripter was found to be significantly constrained. Rupture of the cellulose hollow fiber was observed consistently after about 20 shocks from the XL-1 lithotripter at an output voltage of 20 kV. These results confirm experimentally that SWL-induced cavitation in vivo can be significantly constrained by the surrounding tissue, and large intraluminal bubble expansions could cause rupture of capillaries and small blood vessels.

Purpose: Bladder stones are common in patients with spinal neural tube defects but there are little data on the incidence of renal calculi in this population. We examined the incidence, nature and risk factors of nephrolithiasis in our clinic population of patients with neural tube defects., Materials and Methods: We retrospectively reviewed the charts and radiological studies of 327 patients followed at our neural tube defects clinic with routine radiological imaging of the urinary tract. Additional confirmatory studies were performed when stones were noted., Results: Renal calculi were identified in 20 patients with neural tube defects (6.1%). The incidence of nephrolithiasis increased with age. Renal stones were noted in 19 patients (10.7%) 12 years old or older. Management of the stones in these patients resulted in overall 53% stone-free and 87% recurrence rates after intervention. Major risk factors for new and/or recurrent renal stone formation were bacteriuria in 95% of the cases, lower urinary tract reconstruction in 80%, pelvicalicectasis in 70%, vesicoureteral reflux in 65%, a thoracic level spinal defect in 60% and renal scarring in 55%., Conclusions: These data suggest that there is a higher incidence of nephrolithiasis in patients with neural tube defects than in the general population and the risk of stone recurrence is also elevated. Most patients with stones had undergone lower urinary tract reconstruction. Other risk factors were bacteriuria, pelvicalicectasis, vesicoureteral reflux and a thoracic level neural tube defect.

Because of their resistance to fragmentation, treatment of brushite stones is a big problem. This study was performed to look for an improvement in therapeutic strategies by using artificial stones made of brushite (Bon(n)-stones), which are comparable to their natural counterparts. Using an ultrasound transmission technique, longitudinal wave propagation speeds were measured at different time intervals during treatment with hemiacidrin. From these and density measurements, transverse wave speed, wave impedance and dynamic mechanical properties of the artificial stones were calculated. Moreover, the microhardness of artificial stones was measured and investigations on shock wave lithotripsy (SWL) combined with initial chemolytic treatment of the stones were performed. The suggestion was confirmed that stone fragility and thus SWL can be improved by varying the physical properties of brushite stones through treatment with hemiacidrin. Additionally, we demonstrated the efficacy of Suby G in dissolving artificial brushite stones using an experimental arrangement simulating the physiological conditions in the upper urinary tract. Moreover, the efficacy of four different intracorporeal lithotripsy devices (electrohydraulic, pneumatic, laser and ultrasound) was tested and it was shown that electrohydraulic lithotripsy seems to be the best system for comminution of brushite stones.

With the advances in telemedicine and virtual consultation services comes the need for state-of-the-art endoscopic imaging techniques and equipment. Concomitant with current day concerns of cost containment, the ability to utilize the aforementioned tools in a cost-effective fashion that lowers operating expenses, accurately depicts procedures, and expedites chart documentation is paramount. We report on a fast and efficient way to obtain and store images during endoscopic procedures, which can be stored on standard 3.5-inch floppy disks using an innovative digital image recorder. These images are stored as high-resolution (640x480x24) JPEG files, which can be placed in electronic medical records, imported into Internet Web pages, incorporated into slide presentations, and, most importantly, stored in easily accessed archives.

Background and Objective: Digital imaging capabilities have recently been incorporated into a number of video systems. Contrast enhancement when using a rigid or semirigid endoscope improves image definition by seeking out existing transitions in detail. Only the areas of transition are accentuated, whereas areas without detail are unaffected. During flexible endoscopy, fiberoptic bundles create a classic honeycomb appearance. The use of "fiberscope" filters minimizes this appearance by expanding the image of each fiberoptic fiber. We therefore assessed whether new developments in digital video image processing have improved image quality for endoscopic surgery., Materials and Methods: Fifty urologists reviewed a video playback of various endourologic procedures. The type of endoscope was identified, but the urologic surgeon was blinded to the level of enhancement (high or low) or fiberscope filter (A or B) used. Each video clip was scored from 1 to 5 for the following image variables: identification of structure, detail of image, and background noise or interference. All results were averaged and compared using Student's paired t-test., Results: During rigid endoscopy, the high and low digital enhancement settings were both superior to no enhancement (P < 0.001), and high enhancement was better than low (P < 0.001). With semirigid endoscopic procedures, high and low digital enhancement were comparable but were superior to no enhancement (P < 0.001). Filters A and B were no better than no enhancement. There was a significant improvement noted with the use of filter A or B during flexible ureteroscopy over no enhancement (P < 0.001). In addition, filter A was better than filter B (P < 0.001)., Conclusions: Digital enhancement settings during video endoscopy significantly improve images from rigid and semirigid endoscopes. The digital fiberscope filter significantly improves images obtained during flexible ureteroscopy. Digital image enhancement capabilities should be strongly considered when upgrading video systems. Digital technology must be further studied to improve clinical video imaging during endoscopic surgery.

Purpose: Telemedicine has become a common method for the transmission of images and patient data across long distances. Our goal was to assess the efficiency and accuracy of Photomailer MD software, a store-and-forward telemedicine system, in the urologic setting., Methods: Photomailer MD software was loaded on two computers in the host institution, one with a T1 connection to the Internet and the other with a dial-up modem connection (24,000 bits/second), and computers at three remote sites. A total of 14 clinical cases, comprised of digitized histories and radiographic images, were sent to the remote institutions four separate times using the four transmission modes available: nonencrypted, 56-bit encryption, 128-bit encryption, and 128-bit encryption with password. The following data points were recorded: file size before and after encryption, file transmission times, and diagnostic accuracy of the remote urologists. One-way ANOVA was used to compare mean values statistically, while the z-test was used to compare diagnostic accuracies., Results: Encryption increased the file size by a mean of 37.8%, with the three encryption modes increasing file sizes by the same number of kilobytes. When a dial-up modem was used, encrypted files required a significantly longer transmission time (P < 0.05) than the unencrypted files. The same trend was seen with the T1 connection, although the differences often were not significant. When T1 transmission times were compared with modem times with other variables held constant, modem times were significantly longer (P < 0.05). Diagnostic accuracies for each of the three remote centers ranged from 85.7% to 100%. Differences in accuracy rates between attending physicians and residents were not significant., Conclusions: Photomailer MD provides a secure, convenient, and affordable method of transmitting patient images and records via the Internet. Transmission speed was significantly greater when using a T1 line and also tended to be faster when files were not encrypted. There was no significant difference in transmission time among the three encryption modes; therefore, 128-bit encryption with a password should be used to maximize security. Diagnostic accuracies were comparable to those in the literature. In general, 640 x 480-pixel resolution was adequate for urologic diagnoses, although higher-resolution images may improve accuracy.

Urologists are faced with increasing demands for clear documentation of their work. We report the use of a digital camera in our practice to capture images throughout the urologic setting. The digital camera was a quick and convenient means of obtaining good quality reproductions of radiographic and pathologic findings. Use of the camera greatly enhanced the efficiency of our practice by allowing incorporation of images into patient records and an image library.

Background: Further advances in endoscope technology have allowed the development of a new generation of tightly packed fiberoptics encased within a rigid ureteroscope. The tips of these semirigid ureteroscopes measure between 5.0F and 11.9F, and their working channels measure between 1.8F and 5.5F, which allows passage of routine endoscopc instruments. Additionally, several manufacturers have recently produced straight-channel fiberoptic semirigid endoscopes with an offset lens which allow usage of rigid lithotripsy devices. New fiber-packing techniques provide numerous pixels within the image bundle. These ureteroscopes have varied distal lens systems, but all have excellent vision in the field of view., Methods: Over the past 28 months, we have performed transurethral ureteroscopy in 187 patients, having utilized semirigid ureteroscopes in 158 patients for diagnostic procedures (8.7 %), stone manipulation (78.7 %), removal of migrated stents (4.4%), and surgery of stricture, tumor, or foreign bodies (8.2%). In more than 50% of our cases, ureteral dilation was not necessary, and the semirigid ureteroscope was passed to the area of interest without difficulty., Results: We accessed the site of pathology in 96.2% of patients. Overall, complications occurred in 6.9% of patients. However, of these problems, 93.6% were small ureteral perforations (only three of which were caused by the semirigid ureteroscope itself), and all cases but one were managed successfully by a ureteral stent. No postoperative strictures were noted., Conclusion: This new generation of semirigid fiberoptic ureteroscopes represents another significant advance in the endourologic management of ureteral disease.

In today's medical environment, efficiency and accuracy are the keys to successful outcomes. This concept is especially applicable during video endoscopic imaging, where image clarity is of utmost importance for medical applications. One of the most exciting advances in video endoscopy is the development of digital image storage devices. We report on a fast and efficient way to grab and store images during endoscopic procedures. Images can be stored on standard 3.5" floppy disks using an innovative new digital image recorder. The images are stored as high resolution JPEG files (640 x 480 x 24) for excellent clarity and detail. Once loaded onto the computer or network, the images can be placed into electronic medical records, imported into internet web pages, incorporated into slide presentations, and most importantly, stored in well organized archives which take up a minimum of space and are easily accessed by multiple users. This digital image recorder provides a complete system for acquiring images on a standard format 3.5" floppy disk--the world's most ubiquitous storage format.

We compared the impact of various energy settings, frequency, and fiber diameters on the stone fragmentation capabilities of the holmium laser. Stone phantoms, made from plaster of Paris and uniform in weight, were treated with one of two laser fiber sizes: small (200 and 365 microm) and large (550 and 1000 microm). Stones were immersed in water and fragmented for 3 minutes at 0.5, 1.0, or 2.0 J and 5, 10, or 15 Hz. The mean percentage decrease in weight in the two groups was compared using one-way ANOVA. The effect on flexible ureterorenoscope deflection of the small fibers was tested in two different ureterorenoscopes. Raising the energy level when using the small fibers resulted in more weight loss (P < 0.05). Increasing the frequency up to 10 Hz also resulted in a significant increase in weight loss (P < 0.05), yet above 10 Hz, there was no significant additional weight loss noted for either small fiber. There was no significant difference in the weight loss produced by the two fibers unless the energy setting was >1.0 J. Studies with the large fibers demonstrated similar results, with significant increments of weight loss occurring with increased energy (P < 0.05), while nonsignificant differences were seen for the two fiber diameters. Increasing laser frequency up to 15 Hz resulted in a significant increase in weight loss for the large fibers. Loss of ureterorenoscope deflection ranged from 7% to 16% and 18% to 37% for the 200-microm and 365-microm fibers, respectively. Small-diameter fibers, in combination with semirigid or flexible ureteroscopes, should be used to treat upper urinary tract stones. The 365-microm fiber should be utilized for the management of ureteral stones, as minimal endoscopic deflection is required to access these calculi. Because the 200-microm fibers are considerably more expensive, their use should be reserved for fragmentation of intrarenal calculi, where maximum deflection is required during flexible ureterorenoscopy. The ideal energy and frequency settings for the small fibers are <1.0 J and 5 to 10 Hz. Larger fibers can be used for managing bladder or renal calculi, as there is no need for significant fiber deflection. The 550-microm fiber is preferred, as it is comparable in efficacy to the 1000-microm fiber and is less expensive. Energy and frequency can be maximized to 2.0 J and 15 Hz without damage to the fiber, but visibility can be affected by high frequencies. Appropriate fiber selection and energy/frequency settings will allow access to most stones throughout the urinary tract, maximize fiber life, and minimize fiber expense.

Objectives: To assess the safety and efficacy of ureteroscopy and holmium laser in patients with known bleeding diatheses and upper tract calculi or transitional cell carcinoma (TCC)., Methods: Eight patients with stone disease and 1 patient with upper tract TCC were treated ureteroscopically with the holmium laser. The mean age was 58.3 years (range 42 to 74). Six patients were receiving Coumadin, with a mean international normalized ratio (INR) of 2.1 (normal INR less than 1.1). Two patients were thrombocytopenic, and 1 had von Willebrand's disease. None of the bleeding diatheses were corrected before surgery. Semirigid or flexible ureteroscopes were used to access the ureter or intrarenal collecting system. The holmium laser was used to fragment calculi or ablate tumor., Results: Only 1 patient had a postoperative bleeding complication related to the procedure, involving an episode of oliguria secondary to a small ureteral clot. This cleared without surgical intervention. Another patient developed an episode of epistaxis after administration of ketorolac for pain. Six of 7 patients who underwent laser fragmentation for calculi were stone free on follow-up intravenous urogram at 1 month, and no tumor recurrence was noted in the patient with TCC (follow-up of 4 months)., Conclusions: Ureteroscopy allowed excellent access to all regions of the upper tracts, and holmium laser fragmentation of calculi or ablation of tumor was effective in managing each particular problem. Use of the holmium laser with ureteroscopic access provides a safe and acceptable combination for treating upper tract pathology in patients with uncorrected bleeding diatheses. As a result, these patients can avoid added costs of extended hospital stay and risks associated with transfusions.