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.

Ureteroscopy for pediatric urolithiasis: an evolving first-line therapy.

OBJECTIVES: To present in a retrospective report a contemporary series of patients aged 14 years and younger who were treated for stones with ureteroscopy at our institution from 1991 to 2002. With the improvement and miniaturization of ureteroscopes and ancillary instruments, the endoscopic treatment of renal and ureteral calculi in children has become more feasible. METHODS: A retrospective chart review was performed of 23 patients aged 14 years and younger who had undergone ureteroscopy for the treatment of ureteral or renal calculi at our institution. RESULTS: A total of 27 stones were treated in 23 patients. Of the 27 stones, 18 were in the distal ureter, 5 in the mid ureter, 2 in the proximal ureter, and 2 in the renal pelvis. Ureteral dilation was performed in 4 (17.4%) of the 23 patients. The lithotripsy modalities used were holmium:yttrium-aluminum-garnet laser in 16 (69.6%), electrohydraulic lithotripsy in 3 (13%), a combination of holmium laser and electrohydraulic lithotripsy in 2 (8.7%), and basket extraction alone in 2 (8.7%) of 23 patients. Ureteral stents were placed in 21 (91.3%) of 23 patients. The average operative time was 46.9 minutes (range 15 to 92). In 21 (91.3%) of 23 patients, postoperative imaging was available and revealed that 20 (95.2%) of the 21 patients were rendered stone free. Two patients were lost to follow-up. No intraoperative complications occurred. One patient was treated postoperatively with intravenous antibiotics for transient fever. CONCLUSIONS: Ureteroscopy is safe and effective in the management of ureteral and renal calculi in children. In our institution, it has emerged as a valid first-line therapy for the treatment of pediatric urolithiasis.

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

Malignancy in horseshoe kidneys: review and discussion of surgical implications.

OBJECTIVE: Horseshoe kidney is one of the most common congenital anomalies of renal structure. Not infrequently, surgical management of both benign and malignant disorders is required in patients with horseshoe kidney due to the susceptibility to certain conditions. The literature suggests a greater proclivity to certain renal tumors with this anomaly. We present three cases of malignancy in horseshoe kidneys. The unique technical challenges presented by these cases and the surgical approaches are discussed. METHODS: Three patients with tumors involving horseshoe kidneys are reviewed and their management discussed. RESULTS: Two patients were found to have renal cell carcinoma (RCC) and one had transitional carcinoma (TCC). Computed tomography (CT) and angiography were used in the work-up and preoperative planning of these cases. One patient with RCC received pre-operative renal artery embolization. Partial nephrectomy was performed in each patient with an aim at early vascular control of the tumors, identification of the collecting systems and ureters, as well as ensuring a 1 cm surgical margin. No patient required dialysis post-operatively. One patient died in the early post-operative period of a myocardial infarction; one patient developed brain metastases 18 months post-operatively, received palliative radiation and is alive 42 months after surgery; the other patient was free of disease for approximately 36 months but recently developed osseous metastases to her pelvis. CONCLUSIONS: Techniques developed for partial nephrectomy may be used in the treatment of tumors in horseshoe kidneys. Survival is related to the grade and stage of disease.

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.

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.

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.

Treatment of caliceal diverticular stones: transdiverticular percutaneous nephrolithotomy with creation of a neoinfundibulum.

PURPOSE: To evaluate transdiverticular percutaneous nephrolithotomy (TDPN) with creation of a neoinfundibulum in the treatment of caliceal diverticular stones. PATIENTS AND METHODS: Between 1990 and 1998, 18 patients with symptomatic calculi in caliceal diverticula underwent TDPN. Transdiverticular puncture into the renal collecting system with creation of a neoinfundibulum was used, eliminating the need for prolonged probing with a wire for the neck of the diverticulum. Eight diverticula were upper polar, six were interpolar, and four were in the lower pole. Stones were endoscopically treated with use of Lithoclast (Electromedical Systems, Lausanne, Switzerland), graspers, ultrasound, or a combination of these methods. RESULTS: Sixteen kidneys (89%) were rendered stone-free at discharge. Two kidneys (11%) were left with stone fragments of 5 mm or smaller. Hospital stay ranged from 3 to 15 days (average, 7 days). Procedure time ranged from 45 to 169 minutes (average, 87 minutes). One patient developed a left renal-pleural fistula, which closed 1 week after chest tube drainage. No other complications were encountered for an overall complication rate of 6%. CONCLUSION: TDPN is a safe and effective method for treating caliceal diverticular stones, with a complication rate comparable to other methods.

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.

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.

Holmium:YAG lithotripsy in children.

PURPOSE: We determined the safety and efficacy of holmium:YAG lithotripsy in children. MATERIALS AND METHODS: We retrospectively reviewed the records of all holmium:YAG lithotripsy done in patients 17 years old or younger. Demographic, preoperative, intraoperative and postoperative data were collected. RESULTS: A total of 9 boys and 10 girls (26 stones) with a mean age of 11 years (range 1 to 17) were treated with holmium:YAG lithotripsy, which was chosen as initial therapy in 10 (53%). Retrograde ureteroscopy was performed in 15 patients to treat 13 ureteral and 6 renal calculi, and percutaneous nephrolithotripsy was done in 4 to treat 3 ureteral and 4 renal calculi. A complete stone-free outcome after 1 procedure was achieved in 16 children (84%) and 3 patients were rendered stone-free after 2 procedures. No patient had an intraoperative injury. Followup ranged from 0.5 to 12 months (mean 3). Followup imaging has shown no evidence of stricture or hydronephrosis. CONCLUSIONS: Holmium:YAG lithotripsy is safe and effective in children. It is a reasonable option for failed shock wave lithotripsy, or in children with a known durile stone composition or contraindications to shock wave lithotripsy.

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.

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.

Secondary ureteroscopy: results and management strategy at a referral center.

PURPOSE: In an era when extracorporeal shock wave lithotripsy occupies a dominant place in the treatment of urolithiasis ureteroscopy retains an important role in certain circumstances. While often a definitive procedure, ureteroscopy can be associated with potential risks and complications. The treatment of patients who have undergone a failed attempt at ureteroscopic stone retrieval or have a complication may be complex. As a tertiary care stone referral center we review our experience with performing salvage ureteroscopy following a previous unsuccessful attempt at endoscopic stone removal. MATERIALS AND METHODS: Between May 1990 and February 1996, 79 patients were referred following an unsuccessful attempt at retrograde endoscopic or basket manipulation for ureteral calculi. A retrospective review of the outcomes of these patients was conducted. Of the patients 11 presented with associated complications, which included ureteral perforation (4), intramural false passage (1) and fever or sepsis (6). Complications were managed by early establishment of urinary tract drainage by stenting or nephrostomy. Among patients without complications elective salvage ureteroscopy was performed. RESULTS: Ureteroscopy was used in 79 patients with a successful outcome (stone-free) in 75 (95%). Followup imaging with renal ultrasound or excretory urography at least 3 months after secondary ureteroscopy was available in 65 patients and showed no evidence of hydronephrosis or delayed stricture formation. CONCLUSIONS: Treating the patient who undergoes a failed attempt at ureteroscopy may be problematic and requires access to a wide array of endourological equipment. Each subsequent treatment should be individualized with consideration given to stone size, location and general health. In the presence of a ureteral injury establishment of early urinary tract drainage is essential. Following stabilization, secondary ureteroscopy can be performed yielding high stone-free rates with minimal complications.

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.

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.

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.

Eutectic mixture of local anaesthetics is not effective for extracorporeal shock wave lithotripsy.

PURPOSE: Eutectic mixture of local anaesthetics (EMLA) produces cutaneous analgesia. This randomized, double blind, placebo controlled study evaluated the efficacy of EMLA cream during extracorporeal shock wave lithotripsy (ESWL) using the Dornier MFL 5000 lithotripter. METHODS: Patients scheduled to undergo lithotripsy of renal or pelviureteric junction stones were randomized to receive either 30 g EMLA cream (E) or placebo (P) over the kidney area 60-90 min before the procedure. During lithotripsy all patients received alfentanil via a PCA machine (dose--10 mu.kg-1, lockout time--three minutes, no basal infusion). Additional bolus doses of 5 micrograms.kg-1 alfentanil were administered by the anaesthetist if analgesia was inadequate. Visual analogue scores (VAS) for pain were documented prior to application of the cream. On arrival in the post anaesthesia care unit VAS pain scores were documented for maximum pain and average pain felt during the procedure as well as for satisfaction of the analgesic technique used. Total time spent in the PACU and the Aldrete scores on arrival were compared. RESULTS: Eighty-three patients completed the study. Demographic data were similar between the two groups. Also, VAS for maximal pain, average pain and satisfaction and the total number of shock waves were similar although the EMLA group received more shock waves at the lower energy level (kV) (P < 0.0001). Total dose of alfentanil, dose as boluses, rate of alfentanil use, total number of PCA attempts and missed attempts were similar. The incidence of adverse events such as bradypnoea, airway obstruction, transient hypoxaemia, pruritus and nausea were small and similar. There was a slightly higher incidence of inadequate analgesia documented by the anaesthetist in the EMLA group. There was no difference between the groups with regards to duration of stay in the PACU, incidence of nausea or Aldrete scores on admission to PACU. CONCLUSIONS: During lithotripsy EMLA cream does not modify the pain perceived nor does it have any opioid sparing effect. It does not facilitate early discharge from the PACU.

Intracorporeal lithotripsy with the holmium:YAG laser.

PURPOSE: Preliminary evaluations of the holmium:YAG laser have demonstrated a variety of potential urological applications, including ablation of soft tissue lesions as well as stone fragmentation. We present our experience with the holmium:YAG laser for intracorporeal lithotripsy of urinary calculi. MATERIALS AND METHODS: During a 24-month period 75 patients underwent 79 laser procedures, including retrograde ureteroscopy for ureteral calculi (71) and fragmentation of caliceal stones remote from the nephrostomy tract during percutaneous nephrolithotripsy (8). RESULTS: Complete stone fragmentation without need for additional procedures or lithotripsy was achieved in 85% of the cases. Treatment failures included 1 case of stone migration, 7 incomplete fragmentation requiring other lithotripsy devices and 3 laser malfunction. One ureteral perforation occurred when the laser was activated without direct visual guidance. CONCLUSIONS: The holmium:YAG laser has demonstrated its efficacy as a method of intracorporeal lithotripsy. Advantages include ability to fragment stones of all composition, and the multipurpose, multispecialty applications of the holmium wavelength. This laser has potential soft tissue effects, and careful attention to technique during lithotripsy is required to avoid ureteral wall injury.