Using 300 Pretreatment Shock Waves in a Voltage Ramping Protocol Can Significantly Reduce Tissue Injury During Extracorporeal Shock Wave Lithotripsy.

Purpose: Pretreating a pig kidney with 500 low-energy shock waves (SWs) before delivering a clinical dose of SWs (2000 SWs, 24 kV, 120 SWs/min) has been shown to significantly reduce the size of the hemorrhagic lesion produced in that treated kidney, compared with a protocol without pretreatment. However, since the time available for patient care is limited, we wanted to determine if fewer pretreatment SWs could be used in this protocol. As such, we tested if pretreating with 300 SWs can initiate the same reduction in renal lesion size as has been observed with 500 SWs.

Comparison of tissue injury from focused ultrasonic propulsion of kidney stones versus extracorporeal shock wave lithotripsy.

Purpose: Focused ultrasonic propulsion is a new noninvasive technique designed to move kidney stones and stone fragments out of the urinary collecting system. However, to our knowledge the extent of tissue injury associated with this technique is not known. We quantitated the amount of tissue injury produced by focused ultrasonic propulsion under simulated clinical treatment conditions and under conditions of higher power or continuous duty cycles.

Experience with more than 1,000 holmium laser prostate enucleations for benign prostatic hyperplasia.

Purpose: Holmium laser prostate enucleation is a contemporary treatment for benign prostatic hyperplasia. We report our experience with more than 1,000 procedures.

Materials And Methods: From June 1998 to March 2009 we performed 1,065 holmium laser prostate enucleations.

Evaluation of shock wave lithotripsy injury in the pig using a narrow focal zone lithotriptor.

Unlabelled: What's known on the subject? and What does the study add? Of all the SW lithotriptors manufactured to date, more research studies have been conducted on and more is known about the injury (both description of injury and how to manipulate injury size) produced by the Dornier HM-3 than any other machine. From this information have come suggestions for treatment protocols to reduce shock wave (SW)-induced injury for use in stone clinics. By contrast, much less is known about the injury produced by narrow-focus and high-pressure lithotriptors like the Storz Modulith SLX.

Randomized controlled, multicentre clinical trial comparing a dual-probe ultrasonic lithotrite with a single-probe lithotrite for percutaneous nephrolithotomy.

Objectives: • To compare the Cyberwand (Gyrus/ACMI, Southborough, MA, USA), a dual-probe ultrasonic lithotrite, with a single-probe ultrasonic lithotrite. • The Cyberwand incorporates coaxial high- and low-frequency ultrasonic probes that work synergistically.

Patients And Methods: • An institutional review board-approved, multicentre, randomized controlled trial to compare the Cyberwand to the Olympus LUS-II (Olympus America, Inc.

Natural orifice translumenal endoscopic surgery: radical prostatectomy in the canine model.

Purpose: The goal of this study is to demonstrate the feasibility of transurethral radical prostatectomy in the canine model. We describe the surgical procedure for natural orifice translumenal endoscopic surgery-radical prostatectomy (NOTES-RP).

Materials And Methods: NOTES-RP was performed on six nonsurvival male canines.

Inaccurate reporting of mineral composition by commercial stone analysis laboratories: implications for infection and metabolic stones.

Purpose: We determined the accuracy of stone composition analysis at commercial laboratories.

Materials And Methods: A total of 25 human renal stones with infrared spectroscopy determined composition were fragmented into aliquots and studied with micro computerized tomography to ensure fragment similarity. Representative fragments of each stone were submitted to 5 commercial stone laboratories for blinded analysis.

Profile of the brushite stone former.

Purpose: The incidence of brushite stones has increased during the last 3 decades and we report our experience with brushite stone formers.

Materials And Methods: From 1996 to 2008 we identified 82 patients with brushite urinary calculi. After institutional review board approval a review of our prospectively collected database was performed.

Experience with more than 1,000 holmium laser prostate enucleations for benign prostatic hyperplasia.

Purpose: Holmium laser prostate enucleation is a contemporary treatment for benign prostatic hyperplasia. We report our experience with more than 1,000 procedures.

Materials And Methods: From June 1998 to March 2009 we performed 1,065 holmium laser prostate enucleations.

A novel drug eluting ureteral stent: a prospective, randomized, multicenter clinical trial to evaluate the safety and effectiveness of a ketorolac loaded ureteral stent.

Purpose: We evaluated the short-term safety and efficacy of a ketorolac loaded ureteral stent compared to a standard stent (control).

Materials And Methods: In this prospective, multicenter, double-blind study patients were randomized 1:1 to ketorolac loaded or control stents after ureteroscopy. The primary end point was an intervention for pain defined as unscheduled physician contact, change in pain medication or early stent removal.

Shock wave lithotripsy: advances in technology and technique.

Shock wave lithotripsy (SWL) is the only noninvasive method for stone removal. Once considered as a primary option for the treatment of virtually all stones, SWL is now recognized to have important limitations that restrict its use. In particular, the effectiveness of SWL is severely limited by stone burden, and treatment with shock waves carries the risk of acute injury with the potential for long-term adverse effects.

Holmium laser enucleation of the prostate for prostates larger than 175 grams.

Background And Purpose: Open simple prostatectomy has been considered the treatment of choice for symptomatic benign prostatic hyperplasia (BPH) of large prostates because traditional endoscopic techniques have not proven either effective or feasible. We present our experience with holmium laser enucleation of the prostate (HoLEP) for glands >175 cc.

Methods: An Institutional Review Board approved prospective database has been maintained since January 1999 for all HoLEP procedures.

Percutaneous management of caliceal diverticuli.

Background And Purpose: Caliceal diverticula are rare congenital abnormalities that can become symptomatic if associated with a calculus or infection. We review percutaneous management of caliceal diverticula.

Methods: Pathogenesis, clinical evaluation, management options, and recommended follow-up for symptomatic caliceal diverticula are reviewed.

Assessing the impact of ureteral stent design on patient comfort.

Purpose: We assessed the near term comfort of newly designed ureteral study stents or marketed control stents, including Polaris and Percuflex stents. Study stents had distal 6Fr pigtail ends with 3Fr or less loops. Decreased material in situ was hypothesized to enhance comfort.

Potential for cavitation-mediated tissue damage in shockwave lithotripsy.

Purpose: Shockwave lithotripsy (SWL) injures renal tissue, and cavitation has been reported to mediate some of these effects. Much of the work characterizing the cavitation injury of SWL has been performed in small animals or in vitro. We describe experiments that promote cavitation during SWL and estimate the spatial distribution of the resulting hemorrhagic lesion in a large-animal (porcine) model of clinical lithotripsy.

Techniques for fluoroscopic percutaneous renal access.

Purpose: Percutaneous nephrolithotomy has undergone considerable evolution since its introduction in the 1970s, which has been driven by advances in access techniques, instrumentation and endoscopic technology. Recent reports suggest an increase in the number of percutaneous stone treatments being performed. However, despite the increasing use of percutaneous nephrolithotomy a minority of urologists obtain their own access.

In vitro assessment of a novel dual probe ultrasonic intracorporeal lithotriptor.

Purpose: The Cyberwand (Cybersonics, Erie, Pennsylvania) is a novel intracorporeal lithotrite that uses coaxial ultrasonic elements operating at 2 frequencies. We compared this device to the LithoClast(R) Ultra, which we previously noted is the most efficient commercially available intracorporeal lithotripsy device.

Materials And Methods: An in vitro test system was used to assess the efficiency of stone penetration for the Cyberwand and the LithoClast Ultra.

The pathogenesis of calyceal diverticular calculi.

Controversy exists over whether metabolic factors or urinary stasis predominate in the pathogenesis of calyceal diverticular calculi. We performed a study to better define the effects urinary stasis and metabolic abnormalities have in the pathogenesis of calyceal diverticular stones. Twenty-nine patients who underwent percutaneous treatment of calyceal diverticular calculi were studied.

Renal histopathology of stone-forming patients with distal renal tubular acidosis.

To define the renal tissue changes in stone-forming patients with distal renal tubular acidosis (dRTA), we performed intra-operative papillary and cortical biopsies in five patients. The main abnormalities were plugging of inner medullary collecting ducts (IMCD) and Bellini ducts (BD) with deposits of calcium phosphate in the form of apatite; epithelial cell injury and loss was marked. Plugged ducts were surrounded by interstitial fibrosis, but the fibrosis was generalized, as well, and was a main feature of the histopathology even when plugging was not present.

Using Helical CT to Predict Stone Fragility in Shock Wave Lithotripsy (SWL).

Great variability exists in the response of urinary stones to SWL, and this is true even for stones composed of the same mineral. Efforts have been made to predict stone fragility to shock waves using computed tomography (CT) patient images, but most work to date has focused on the use of stone CT number (i.e.

The role of Randall's plaques in the pathogenesis of calcium stones.

Purpose: Knowledge of the inciting lesion in kidney stone formation has remained rudimentary until quite recently. Randall theorized that areas of apatite plaque on the renal papillae would be an ideal site for an overgrowth of calcium oxalate to develop into a calculus. We reviewed in vivo data that have further defined the role of Randall's plaques in stone disease.

Endoscopic evidence of calculus attachment to Randall's plaque.

Purpose: It has been proposed that calcium oxalate calculi begin as small stones attached to the renal papillae at sites of Randall's plaque. However, no study has investigated the prevalence of attached stones in calcium oxalate stone formers or the relationship between stone attachment site and Randall's plaque. In this study we used endoscopic examination of renal papillae in stone formers undergoing percutaneous nephrolithotomy to investigate both issues.