Glenn M Preminger

PURPOSE: The frequency doubled, double pulse Nd:YAG (FREDDY) laser (World of Medicine, Berlin, Germany) functions through the generation of a plasma bubble. Upon bubble collapse a mechanical shock wave is generated, causing stone fragmentation. This mechanism of action is in contrast to the holmium laser, which cause stone destruction by vaporization. Observed clinical stone retropulsion and fragmentation with the FREDDY and holmium lasers has prompted a series of in vitro experiments ...

Minimal emphasis has been placed on the clinical sequelae of residual stone fragments following shock wave lithotripsy. Moreover, there are no studies investigating the role of medical therapy on the course of stone disease in patients with residual fragments. In this retrospective, nonrandomized review, we evaluated 80 patients who had undergone shock wave lithotripsy at various institutions in Texas and were referred to our mineral metabolism clinic for metabolic evaluation and medical ...

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. ...

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 ...

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 ...

BACKGROUND AND PURPOSE: A myriad of minimally invasive options exist for managing symptomatic caliceal diverticula, including shockwave lithotripsy, percutaneous surgery, retrograde ureteroscopy, and laparoscopy. Yet no direct comparisons have been made in the literature of the relative treatment efficacy of ureteroscopy (URS) and percutaneous nephrolithotripsy (PNL). A retrospective review of our patients was performed to determine the most appropriate endoscopic management option for ...

BACKGROUND AND PURPOSE: New-generation flexible ureteroscopes allow the management of proximal ureteral and intrarenal pathology with high success rates, including complete removal of ureteral and renal calculi. One problem is that the irrigation pressures generated within the collecting system can be significantly elevated, as evidenced by pyelovenous and pyelolymphatic backflow seen during retrograde pyelography. We sought to determine if the ureteral access sheath (UAS) can offer ...

PURPOSE: Ureteroscopic laser lithotripsy requires irrigation for adequate visualization and temperature control during treatment of ureteral stones. However, there are little data on how different irrigation and laser settings affect the ureteral wall and surrounding tissues. This effect has become an important consideration with the advent of high-powered lasers. We therefore evaluated the effect of laser settings and irrigation flow on ureteral temperature in an in vitro ...

PURPOSE: There is rising concern over the increasing amount of patient radiation exposure from diagnostic imaging and medical procedures. Patients with nephrolithiasis are at potentially significant risk for radiation exposure due to the need for imaging to manage recurrent stone disease. We reviewed the literature in an attempt to better characterize actual risks and discussed methods to reduce radiation exposure for adult patients with nephrolithiasis.

MATERIALS AND METHODS: A PubMed ...

Lower pole caliceal calculi can be treated by percutaneous nephrolithotomy (PCNL) or by extracorporeal shock wave lithotripsy (ESWL). In previous studies, investigators have noted that stones in lower calices treated with ESWL have a poor clearance rate. This study compared PCNL and ESWL treatments for solitary lower caliceal stones. Thirty-five patients with lower pole caliceal stones were treated with ESWL (Dornier HM3), and 29 patients were treated with PCNL between March 1983 and ...

PURPOSE: The optimal management of lower pole renal calculi is controversial. We compared shock wave lithotripsy (SWL) and ureteroscopy (URS) for the treatment of patients with small lower pole stones in a prospective, randomized, multicenter trial.

MATERIALS AND METHODS: A total of 78 patients with 1 cm or less isolated lower pole stones were randomized to SWL or URS. The primary outcome measure was stone-free rate on noncontrast computerized tomography at 3 months. Secondary outcome ...

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 ...

PURPOSE: The goal of treating ureteral calculi is to achieve complete stone clearance with minimal patient morbidity. Shock wave lithotripsy and ureteroscopy have become standards of care for ureteral calculi. However, the optimal choice of treatment depends on various factors, including stone size, composition and location, clinical patient factors, equipment availability and surgeon capability. Indications for and outcomes data on shock wave lithotripsy and ureteroscopy for proximal ...

OBJECTIVE: To present early experience in managing complex renal calculi using a combined ureteroscopic and percutaneous approach, as complex and branched renal calculi often require multiple access tracts during percutaneous nephrolithotomy (PNL), and the combined use of flexible ureteroscopy and PNL has the potential to reduce the inherent morbidity of several tracts.

PATIENTS AND METHODS: The study included seven patients (mean age 54 years) with multiple, branched, large-volume renal ...

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 ...