Ordnance gelatine as an in vitro tissue simulation scaffold for extracorporeal shock wave lithotripsy.

In vitro shock wave lithotripsy (SWL) research is typically performed utilizing wet coupling lithotriptors with a mesh basket model. This model does not take into account shock wave energy attenuation through tissue. Models using dry coupling lithotriptors rely on immersion chambers and face similar limitations. Ordnance gelatin (OG) displays strength and viscous properties similar to human tissue and is therefore widely used for ballistic tissue injury research. We present our initial experience using an OG tissue simulating scaffold for dry coupling SWL research. Using 10% OG prepared in a disc-shaped mold (five stone wells/gel), we tested the model using a Modulith SLX-F2 lithotriptor and artificial stone phantoms. Following a test of concept run on an empty gel mold and a material integrity check for leakage, we shocked 60 stones (30 narrow focus [NF], 30 wide focus [WF]) in human pooled urine. Half were shocked using gels containing open-ended wells with the remainder closed-ended wells. Fragmentation coefficients (FC) were calculated across both foci and gel models. All gels successfully completed 5,000 shocks (1,000/well) without loss of gel integrity or fluid leakage. The mean FC using open-ended wells was 77.9 ± 7.6% NF and 74.4 ± 4.8% WF, and for closed wells 75.9 ± 8.0% NF and 67.1 ± 3.5% WF. The total model cost including the preparation of gels and begostones was assessed at approximately $1 per stone (Canadian). Ordnance gel serves as an excellent surrogate tissue shockwave scaffold providing an easily manufactured, reproducible and inexpensive model for dry coupling SWL research.

Research priorities for urological care following spinal cord injury: recommendations of an expert panel.

OBJECTIVE: A multidisciplinary panel of experts from Canada and the United States was convened by the Ontario Neurotrauma Foundation (ONF) to establish research priorities in the area of urological care following spinal cord injury (SCI). DESIGN: The panel reviewed a synthesis of published literature in five areas of urology, identified emerging opportunities in the private and public sector, and used a modified Delphi approach to reach consensus on priorities for funding. RESULTS: The panel recommendations included: clinical trials of the safety and efficacy of M3 receptor specific anti-muscarinic agents for bladder hyperactivity in SCI patients; development and testing of protocols for sacral nerve electrostimulation without sacral afferent neurectomy for management of micturition - including selective stimulation of sacral nerve fibers, high frequency blocking of the pudendal nerve to minimize the risk of urethral sphincter co-contraction and genital nerve stimulation for bladder inhibition and incontinence management; clinical trials of the efficacy and safety of intra-urethral valve catheters; trials of the efficacy of probiotics for bacterial interference i.e. to reduce colonization by uropathogens and manage the dual problems of infection and pathogen resistance to anti-microbials: innovations in the prevention or treatment of stone disease (ureteral, bladder and kidney). CONCLUSIONS: The recommendations form the strategic priorities of the ONF SCI grants program for Ontario-based investigators and their partnerships with out-of-province collaborators and organizations.

Electrosurgical vaporization of the prostate in the canine model.

OBJECTIVES: To investigate the histopathologic changes and heating patterns caused by electrosurgical vaporization of the prostate in the living canine model. METHODS: Prostate electrosurgical vaporization was undertaken in the canine model. Temperatures within and near the prostate and of the irrigation fluid were measured during a single pass and during the creation of a vaporized cavity. The prostate and adjacent tissues were examined by gross and microscopic pathology. RESULTS: Coagulation occurred deep to the vaporization zone for 1.38 to 1.44 mm for a single pass of the rolling cylinder and up to 2.52 mm for multiple passes. Thermometry revealed temperature increases of only 4 degrees C 5 mm away from the vaporization site. The largest temperature increases were found in the irrigation fluid as it passed through the prostatic fossa. Microscopic pathology revealed no damage to adjacent tissues. CONCLUSIONS: Electrosurgical vaporization creates minimal deep heating and coagulation beyond the vaporized cavity. The majority of the heat is removed by the irrigation fluid.

Holmium:YAG laser endoureterotomy for treatment of ureteral stricture.

OBJECTIVES: Endourologic techniques ranging from balloon dilation to endoincision with electrocautery, cold knife, and lasers have been increasingly used in recent years for the treatment of ureteral strictures. While the long-term results may not be as reliable or as durable as traditional reconstructive surgical techniques, they can be accomplished with much less morbidity. Recently, the holmium:yttrium-aluminum-garnet (YAG) laser, which possesses both cutting and coagulating properties, has been demonstrated to have many applications in urology. We report our experience with this laser in the endoscopic treatment of ureteral strictures. METHODS: We reviewed the charts and follow-up history of 22 patients in whom the holmium:YAG laser was used to treat ureteral strictures from a variety of causes and including those in ureteroenteric anastomoses. Strictures were either approached in a retrograde fashion with a 6.9F ureteroscope or antegrade with flexible instruments in the cases involving ureteroenteric strictures. The only energy source employed was the laser, followed by balloon dilation. Indwelling stents were left in place for at least 4 weeks postoperatively and follow-up was obtained with radiographic imaging. RESULTS: A minimum 9-month follow-up was available for 18 patients. There were 5 patients who had developed recurrent strictures and were therefore considered treatment failures. Each of these patients failed in less than 3 months and all had either lengthy or complex strictures noted at the time of surgery. One patient was lost to follow-up and three recent patients have follow-up of 3 to 6 months showing no evidence of recurrent stricture formation. Overall, 16 of 21 (76%) patients are clinically well with no evidence of stricture recurrence. CONCLUSIONS: Endoureterotomy for ureteral stricture disease is a minimally invasive, less morbid, but ultimately less successful, alternative to open surgical reconstruction. Stricture length and etiology remain the most important determinants of success. The holmium:YAG laser, with its ability to precisely cut tissue and provide hemostasis and its multiuse potential and compatibility with small rigid and flexible endoscopic instruments, is an ideal tool for performing endoureterotomy.

Microwave thermotherapy for benign prostatic hyperplasia with the Dornier Urowave: results of a randomized, double-blind, multicenter, sham-controlled trial.

OBJECTIVES: To study the efficacy and safety of a new transurethral microwave thermotherapy device (the Urowave) in the treatment of men with clinical benign prostatic hyperplasia (BPH) in a randomized, double-blind, sham-controlled trial. METHODS: A total of 220 patients (mean age 66.2 years) with clinical BPH, an American Urological Association symptom index (AUA SI) of 13 points or more, and a peak flow rate of 12 mL/s or less were enrolled and randomized 2:1 for active versus sham treatment. All treatments were conducted as an outpatient procedure under local anesthesia, with oral sedation and analgesia only. Patients were followed up at 1 week and 1, 3, and 6 months after treatment. RESULTS: The treatments were well tolerated, and no patient received general or spinal anesthesia. The AUA SI dropped from 23.6 to 12.7 points at 6 months (P < 0.05) in the active group and from 23.9 to 18.0 points in the sham-treated group (P < 0.05, between-group difference). Statistically significant improvements were also noted for peak flow rate (7.7 to 10.7 mL/s at 6 months for active treatment, 8.1 to 9.8 mL/s for sham treatment, P < 0.05, between-group difference) and for average flow rate. A decrease in AUA SI of more than 30% was achieved in 72% versus 38% of patients (active versus sham treatment, respectively) and more than 50% in 50% versus 19% of patients. In general, active Urowave-treated patients perceived "a lot" of improvement, whereas sham-treated patients perceived "a little" to "some" improvement. More of the actively treated patients had dysuria and urgency after treatment, and ejaculatory dysfunction (e.g., hematospermia) was more common in actively treated patients as well. Secondary urinary retention after removal of the catheter occurred in 8 patients (5.4%). CONCLUSIONS: The Dornier Urowave transurethral microwave thermotherapy device for treatment of clinical BPH is effective in decreasing symptoms and bother and improving quality of life and flow rate and is superior to sham treatment. Patients perceive a great deal of improvement, independent of their baseline symptom severity. Adverse events are in general transient and mild in nature. Extended follow-up is necessary to document long-term durability of improvements.

Comparison of human telomerase reverse transcriptase messenger RNA and telomerase activity as urine markers for diagnosis of bladder carcinoma.

BACKGROUND: Human telomerase reverse transcriptase (hTERT) has been identified as the catalytic subunit of telomerase ribonucleoprotein complex known to be required for cellular immortality and oncogenesis. Although human telomerase activity (hTA) is considered as a general marker for malignancy based on its presence in most malignant tumors including bladder cancer, its detection in urine is affected by many factors. The objective of this study was to compare the clinical utility of detecting urine hTERT messenger RNA (mRNA) by multiplex hTERT/GAPDH RT-PCR and urine hTA by telomerase repeat amplification protocol (TRAP) in the diagnosis of bladder cancer. METHODS AND RESULTS: Cystoscopy urine samples or bladder washes prospectively collected from 35 patients with confirmed (35) or clinically suspected (5) transitional cell carcinoma (TCC) of the bladder were examined by TRAP, hTERT/GAPDH RT-PCR, and urine cytology. The control group comprised 21 healthy volunteers and 3 patients without TCC. The hTERT/GAPDH RT-PCR test showed significantly higher diagnostic sensitivity than TRAP assay (94.3% vs 48.6%, P <.001) and urine cytology (95.2% vs 61.9%, P =.008) for confirmed TCCs. In particular, for superficial TCCs low grade (I-II), the hTERT/GAPDH RT-PCR test outperformed TRAP (90% vs 25%, P <.001) and urine cytology (91.7% vs 58.3%, P =.46). The overall specificity of the hTERT/GAPDH RT-PCR, TRAP and urine cytology was 92% (22/24), 100% (24/24), and 100% (3/3), respectively. A positive hTERT mRNA expression was also detected in urologic specimens from 3 patients with previous history of TCC, 3 to 6 months before cystoscopic evidence of cancer. CONCLUSION: In this pilot study, the hTERT mRNA expression in urine sediments is a more sensitive marker for diagnosis of TCC of the bladder than hTA and cytology. However, there is a higher false-positive rate.

Retroperitoneal fibrosis: a case report of spontaneous resolution.

AIM: The purpose of this case report is to document an occurrence of spontaneous resolution of idiopathic retroperitoneal fibrosis and to review the investigation and management of this unusual condition. MATERIALS AND METHODS: A detailed case summary of a patient with retroperitoneal fibrosis is presented. Current citations in Index medicus from the English-speaking literature of relevance to the topic were reviewed. CONCLUSIONS: In this patient who refused open surgical intervention, bilateral stent placement allowed stabilization of renal function. CT-guided biopsy did not reveal malignancy. Serial CT imaging demonstrated gradual disappearance of the retroperitoneal mass. From the literature review, spontaneous resolution of this condition appears to be a rare phenomenon. Although often utilized, CT-guided biopsy may fail to exclude the presence of malignancy. Open surgical biopsy of the retroperitoneal mass and ureterolysis remain the standard of care for operative candidates. Establishing renal drainage and considering a trial of steroids or surveillance may be an option in carefully selected individuals.

Endourologic management of seminal vesicle cyst.

Cystic lesions in the region of the seminal vesicles, ejaculatory ducts, or prostate are rare and can be a diagnostic and therapeutic challenge. Open surgery is often necessary for definitive treatment. Recent refinements in transrectal ultrasound imaging and endoscopic instrumentation have expanded the roles of these modalities in the management of retrovesical cysts. We present a case in which a semirigid 6.9F ureteroscope was used to access and drain a seminal vesicle cyst transurethrally, thereby obviating open surgery.

Endoscopic management of ureteral injury after cesarean section.

Ureteral injury is an uncommon complication of cesarean section. As with all iatrogenic ureteral injuries, if the problem is not recognized intraoperatively, the manifestations may be protean. The management of ureteral injury that is first recognized in the early postoperative period must be individualized. We present a case of ureteral injury during a cesarean section in which endoscopic techniques were employed successfully to establish kidney drainage and allow ureteral healing, obviating open surgical repair.

Ureteroscopic decompression of an unusual uroepithelial cyst using the holmium:YAG laser.

We report a case of an unusual uroepithelial cyst arising from a renal calix in an African-American man with sickle cell trait. The lesion was incised and decompressed using a 7.5F flexible ureteroscope in conjunction with the holmium:YAG laser and a 200-microm quartz laser fiber. To our knowledge, endourologic management of this type of lesion has not been described in the literature.

Randomized trial of 10 mL and 20 mL of 2% intraurethral lidocaine gel and placebo in men undergoing flexible cystoscopy.

PURPOSE: To determine if 20 mL of 2% intraurethral lidocaine gel is superior to 10 mL of 2% lidocaine or sterile lubricant for flexible cystoscopy in men. PATIENTS AND METHODS: A randomized, double-blind, placebo-controlled trial was conducted. Sixty men scheduled to undergo diagnostic flexible cystoscopy were randomized to receive either 20 mL of placebo gel (Group I), 10 mL, of 2% lidocaine gel (Group II) or 20 mL of 2% lidocaine gel (Group III). A penile clamp was applied for 15 minutes to ensure consistent indwelling time in all patients. Patients recorded their pain on a 10-cm non-graphical visual analog scale prior to cystoscopy as a baseline, during the procedure, and immediately after the procedure. Patients also recorded their pain and willingness to have the same anesthetic on a 4-point descriptive scale. Heart rate and mean arterial blood pressure (MAP) were recorded at specific intervals throughout the procedure, and increases in mean arterial pressure were considered objective evidence of patient pain. RESULTS: Pain perception was not statistically different in the groups (Group I 4.65, Group II 3.93, Group III 3.57; P = 0.406). Pain assessment and willingness to have the same anesthetic also did not differ statistically among the groups. Similarly, differences in the increases in MAP were not statistically significant between groups. CONCLUSION: Instillation of 20 mL or 10 mL of 2% lidocaine gel has no advantage over plain lubricant in providing anesthesia for flexible cystoscopy in men.

Management of vesical calculi: comparison of lithotripsy devices.

Although endoscopic lithotripsy of bladder stones has been well described and is widely practiced, comparison of the main modalities of mechanical, electrohydraulic, and ultrasonic lithotripsy is lacking. The exact role of these and other modalities such as the Swiss Lithoclast and extracorporeal shockwave lithotripsy is not clearly defined. The safety and efficacy of the various lithotripsy modalities available to treat bladder calculi were reviewed retrospectively over an 18-year period. A total of 106 patients were treated with some form of intracorporeal lithotripsy. In general, all devices proved to be effective with a low rate of complications. The addition of transurethral resection of the prostate to bladder stone management under the same anesthetic was also found to be a safe procedure for moderate benign prostatic hyperplasia. In summary, transurethral endoscopic lithotripsy is a safe and effective method of bladder stone management both alone and in combination with transurethral prostatectomy. All modalities of intracorporeal lithotripsy are effective; however, devices such as ultrasound lithotripters or the Swiss Lithoclast that utilize larger, rigid probes may be more efficient for patients with large or particularly hard vesical calculi.

Ureteral lithotripsy with the electromechanical impactor.

Electrohydraulic lithotripsy (EHL) of ureteral calculi has proved to be an effective and relatively inexpensive method of intracorporeal lithotripsy. However, the potential for significant ureteral injury is an everpresent concern with conventional EHL. The electromechanical impactor (EMI), an innovative modification of a standard EHL probe, has been shown in initial investigations to be capable of fragmenting urinary calculi with a greater margin of safety. Herein, we describe our preliminary experience with this new device in 23 patients with ureteral calculi. In nine patients selected to undergo EMI treatment, the device could not be employed because of either inability to access the stone with the large endoscope required (six cases) or device malfunction (three cases). Among the patients in whom the EMI was used, five required an additional modality of intracorporeal lithotripsy to complete stone fragmentation. In the remaining nine patients, stone fragmentation was achieved with the EMI as the sole modality of lithotripsy, for an overall success rate of 39% (9/23). There were no complications directly related to use of the EMI as noted endoscopically or on postoperative imaging. The EMI appears to be a safe device for intracorporeal lithotripsy. Its application to a large population of patients with ureteral stones may be limited by the probe size (5F), which precludes its use with the smaller rigid and flexible ureteroscopes.

Identifying stone composition using infrared analysis of filtered urine after ureteroscopic lithotripsy.

BACKGROUND AND PURPOSE: With the development of small-caliber ureteroscopes and lithotripsy devices, it is now possible to perform intracorporeal stone fragmentation without dilatation of the ureteral orifice. Ureteral stones are typically fragmented into small particles that can be difficult to retrieve for stone analysis. Infrared spectroscopy (IRS) of the precipitate from urine after intracorporeal lithotripsy represents a method for obtaining stone analysis. PATIENTS AND METHODS: A total of 69 patients underwent ureteroscopic lithotripsy with the holmium laser or the electrohydraulic probe for stones in the ureter (N = 65) or kidney (N = 4). Each patient's bladder was then drained and the urine filtered. The resulting precipitate was analyzed using IRS. RESULTS: The amount of material for analysis was < or =1 mg in 56 patients (82%). Stone composition was positively identified in 44 patients (64%). Material suitable for analysis was recovered from 73% of patients when the bladder was drained with a cystoscope sheath compared with 43% when a urethral catheter was used (P = 0.03). There was no significant difference in pretreatment stone size in the patients who had a positive v a negative result (11.7 mm v 10.9 mm; P = 0.06). Similarly, the stone location was not significantly related to the likelihood of positive analysis (P = 0.29). CONCLUSION: Straining the urine after ureteroscopic intracorporeal lithotripsy and analyzing the precipitate with IRS is able to identify stone composition in the majority of patients. This method is especially useful in the setting of holmium laser lithotripsy, in which the majority of the stone is converted to spontaneously passable particles.

Results of shockwave lithotripsy for pediatric urolithiasis.

BACKGROUND AND PURPOSE: Shockwave lithotripsy (SWL) is widely practiced in the management of pediatric urolithiasis. However, the efficacy, need for ancillary procedures, and treatment-related complications are not as clearly defined as in the adult population. We reviewed the outcomes of SWL in the pediatric population at our lithotripsy unit. PATIENTS AND METHODS: A retrospective review of all patients

Percutaneous suprapubic cystolithotripsy for treatment of large bladder calculi.

BACKGROUND AND PURPOSE: The treatment options available for managing bladder calculi include transurethral cystolithotripsy, open cystolithotomy, and shockwave lithotripsy. For larger calculi, transurethral treatment can be time consuming, and the manipulation has the potential to cause urethral injury. Percutaneous suprapubic cystolithotripsy represents another treatment option for bladder calculi which is effective and minimally invasive. PATIENTS AND METHODS: Fifteen patients had bladder calculi treated with percutaneous cystolithotripsy over a 3-year period. The mean stone size was 39 mm (range 10-64 mm). Stones were single in seven patients and multiple in eight patients. The indications for cystolithotripsy were stone size >3 cm, multiple stones >1 cm, and inability to perform transurethral cystolithotripsy because of patient anatomy. Percutaneous suprapubic cystolithotripsy was done through either a 30F or a 36F cystotomy tract. Fragmentation and removal was performed with a 26F rigid nephroscope and the pneumatic Swiss Lithoclast. Suprapubic and urethral catheters were placed postoperatively in all patients. RESULTS: Each patient was cleared of the stone burden with a single procedure, and there were no major complications. The mean duration of suprapubic catheterization was 2.6 (range 1-5) days. CONCLUSION: Percutaneous suprapubic cystolithotripsy is an effective and safe technique for treating large bladder calculi. It is minimally invasive, avoids urethral injury, and, in combination with the pneumatic Swiss Lithoclast, can be used to fragment and remove large and hard bladder calculi.

Preliminary experience with holmium: YAG laser lithotripsy.

Lithotripsy with the pulsed-dye laser has been shown to be a safe and effective method of intracorporeal urinary stone fragmentation. Recently, a new device, the holmium: YAG laser, has been developed with both soft tissue and lithotripsy applications. We present our preliminary experience with the Ho:YAG laser for lithotripsy of urinary calculi. Ureteroscopy and lasertripsy resulted in successful fragmentation of ureteral stones in 92% of 21 patients when the laser was used alone or in combination with electrohydraulic lithotripsy. One complication directly related to the use of the laser occurred, a ureteral perforation, when the device was utilized under fluoroscopic control. In four patients undergoing percutaneous flexible nephrolithotripsy, the laser demonstrated utility in fragmenting caliceal stones remote from the nephrostomy tract. In summary, the Ho:YAG laser has demonstrated its efficacy as a method of intracorporeal lithotripsy. The tissue effects of this device, as well as the optimal energy/pulse and frequency settings, need further evaluation in order to minimize the risks of tissue injury.

Oliguria during laparoscopic surgery: evidence for direct renal parenchymal compression as an etiologic factor.

Abdominal insufflation during laparoscopy has been associated with transient oliguria, which abates after desufflation. Direct renal compression evoking a Page kidney effect was proposed as a mechanism. In an effort to confirm this theory, the left kidney was subjected to 15 mm Hg compression in six anesthetized mongrel dogs. For this, a pressure cuff was placed around the kidney excluding the renal hilar structures. The contralateral kidney was left untouched to serve as a control. After a steady-state period, the pressure cuff was inflated to 15 mm Hg for 2 hours. Cuff desufflation was followed by a 1-hour recovery period. Urine output, glomerular filtration rate (GFR), and effective renal blood flow (ERBF) were measured for both kidneys during each clearance period. For the treated kidneys, the mean urine output decreased 63% (P < 0.05) during compression and increased 109% (P < 0.05) after cuff desufflation. The GFR decreased 21% (P < 0.01) during compression and increased 25% (P < 0.05) during recovery. The ERBF decreased 26% (P < 0.05) during compression, and during the 1-hour recovery period, ERBF did not recover to baseline values. For the control kidneys, there were no significant changes in urine output or GFR during the experimental and recovery periods. These data support the view that direct renal parenchymal compression is an important factor in the development of insufflation-induced oliguria. The clinical implications of insufflation-induced oliguria during laparoscopy deserve further investigation.

Soft-tissue applications of the holmium:YAG laser in urology.

The holmium:YAG laser possesses both ablative and hemostatic properties and in preliminary clinical use has demonstrated many potential urologic applications. We review our initial experience in treating a variety of soft-tissue lesions of the urinary tract with this laser. A total of 51 patients underwent 53 procedures including superficial bladder tumor ablation (25), incision of ureteral stricture (15), incision of urethral stricture (6), relief of ureteropelvic junction obstruction (3), incision of bladder neck contracture (2), and ureteral tumor ablation (2). Procedures were considered successful, with no further intervention or alternative energy source required, in 81% of the cases. The laser demonstrated precise hemostatic cutting and warrants further investigation as a multipurpose urologic laser.

Evaluation of Doppler ultrasonography and dynamic contrast-enhanced CT in acute and chronic renal obstruction.

The development of a reliable, minimally invasive method of distinguishing physiologically significant renal obstruction from dilation without obstruction would have important clinical implications. As it is well known that renal blood flow decreases over time in the presence of obstruction, we investigated the ability of color flow Doppler ultrasonography and dynamic contrast-enhanced CT scanning to detect changes in blood flow in unilaterally obstructed porcine kidneys. In the initial phase of this study, the effect of acute unilateral obstruction were studied in nine pigs. The resistive index (RI) was measured with Doppler ultrasonography, and renal blood flow was quantitated with dynamic CT using tracer kinetic principles and deconvolution. The RI measurements were unable to distinguish between the obstructed kidneys and their controls. Dynamic CT scanning demonstrated a greater fall in blood flow in the obstructed kidney, and this change was significantly different from baseline. The same findings were supported by radiolabelled microsphere blood-flow measurement. In the chronic portion of the study, after surgical creation of a partial ureteric obstruction, the kidneys were studied by both techniques at 1, 2, and 3 weeks. Again, RI was unable to demonstrate any difference between obstructed and unobstructed kidneys, while CT showed a progressive fall in blood flow in each successive week that was statistically significant. Dynamic contrast-enhanced CT scanning is a promising diagnostic tool that might be used to distinguish a functionally significant renal obstruction from nonobstructive dilation. Further clinical studies to validate this technique are warranted.