Search results for "Calculi"

Retrograde endoureterotomy as a treatment option for impacted calculus in the ureterointestinal junction

2021

Introduction: In patients with a history of radical cystectomy and with intestinal diversion, urolithiasis in the upper urinary tract is a frequent event. Material and methods: We describe for the first time a case of retrograde endoureterotomy used to treat a calculus proximal to the ureterointestinal junction. Results: This technique is of interest when antegrade access is not possible. In our example, after passing the guidewire percutaneously, and externalize it through the stoma, the left meatus was reached with a resectoscope inserted through the ileal duct. After the use of a balloon to prevent migration of the calculus, a retrograde endoureterotomy was performed with a Collins knife…

Choosing the nephrostomy size after percutaneous nephrolithotomy.

2011

Purpose: To evaluate the effect of nephrostomy tube size on perioperative outcomes of percutaneous nephrolithtotmy (PCNL). Methods: Forty-five well-matched patients with normal renal function were prospectively divided in two nonrandomized groups after uneventful PCNL (to receive either a 22-Fr, group 1 (n = 24 pts), or a 12-Fr nephrostomy tube, group 2 (n = 21 pts)). In all a balloon nephrostomy catheter with detachable funnel (Rüsch Teleflex, Germany) was used. A Visual Analogue Scale (VAS) for measuring the pain was administered 8 and 24 h after the procedure. Postoperative analgesics use (Ketoralac Tromethamine 30 mg), pre- and postoperative Hb, renal function and urinary leaks were reg…

Low-frequency extracorporeal shock wave lithotripsy improves renal pelvic stone disintegration in a pig model.

2009

OBJECTIVE To compare disintegration rates for renal stones treated by 60 vs 120 shock waves (SW)/min at the same energy settings, using standardized validated artificial stones in a pig model. MATERIALS AND METHODS Gypsum artificial stones (13 × 6 mm) were inserted into the renal pelvis on either side of 12 anaesthetized pigs by open surgery. Extracorporeal SW lithotripsy (ESWL) was applied using a new electromagnetic lithotripter (Lithoskop®, Siemens AG Healthcare, Munich, Germany) at 60 and 120 SW/min; 3000 SW were applied to each kidney with the same energy settings. Stone fragments were collected after nephrectomy, passed through calibrated test sieves, and weighed. Fragment size catego…

Surgical aspects of urolithiasis in children.

1991

Operative management of renal calculi has changed radically in the last decade. New operative techniques. the use of intra-operative ultrasound and Doppler sonography have even made possible the removal of complete staghorn calculi in short and kidney-preserving procedures. The introduction of percutaneous nephrolithotomy and stone extraction using a specially designed ureteroscope and, above all, the clinical application of extracorporeal shock wave lithotripsy have made stone surgery less invasive and have provided a higher rate of preservation of kidney function.

MicroRNAs and their role in the malignant transformation of oral leukoplakia: a scoping review

2021

Background MiRNAs are small non-coding RNAs that regulate gene expression at the post-transcriptional level and have been associated with malignant transformation of oral epithelial precursor lesions such as oral leukoplakia. The aim was to perform a scoping review of the contemporary literature about the different roles of miRNAs during the malignant transformation of oral leukoplakia. Material and Methods We conducted a systematic search with the following MeSH terms: ‘oral leukoplakia’, ‘carcinoma in situ’, ‘microRNAs’, ‘mouth neoplasms’ and ‘epithelial–mesenchymal transition’ in PubMed/MEDLINE, EMBASE and SpringerLink. Results Fifteen articles were included for analysis, among which in …

Direct nucleation of calcium oxalate dihydrate crystals onto the surface of living renal epithelial cells in culture

1998

Direct nucleation of calcium oxalate dihydrate crystals onto the surface of living renal epithelial cells in culture. Background. The interaction of the most common crystal in human urine, calcium oxalate dihydrate (COD), with the surface of monkey renal epithelial cells (BSC-1 line) was studied to identify initiating events in kidney stone formation. Methods. To determine if COD crystals could nucleate directly onto the apical cell surface, a novel technique utilizing vapor diffusion of oxalic acid was employed. Cells were grown to confluence in the inner four wells of 24-well plates. At the start of each experiment, diethyloxalate in water was placed into eight adjacent wells, and the pla…

Sialic acid-containing glycoproteins on renal cells determine nucleation of calcium oxalate dihydrate crystals

2001

Sialic acid-containing glycoproteins on renal cells determine nucleation of calcium oxalate dihydrate crystals. Background The interaction between the surfaces of renal epithelial cells and calcium oxalate dihydrate (COD), the most common crystal in human urine, was studied to identify critical determinants of kidney stone formation. Methods A novel technique utilizing vapor diffusion of oxalic acid was employed to nucleate COD crystals onto the apical surface of living cells. Confluent monolayers were grown in the inner 4 wells of 24-well culture plates. To identify cell surface molecules that regulate crystal nucleation, cells were pretreated with a protease (trypsin or proteinase K) to a…

New concept of the pathogenesis of urinary lithiasis.

1948

Laser fragmentation of pancreatic duct stones using a rhodamine laser with an automatic stone-tissue detection system. Basic in-vitro studies

1997

OBJECTIVES The aim of our study was to examine the suitability of a rhodamine 6G laser with an integrated stone-tissue detection system (STDS) for fragmenting pancreatic stones. METHODS A total of 64 pancreatic duct stones were measured for weight, diameter, main chemical components and in some cases for their computerized tomography density. Recognition of all stones was checked with the standard STDS or a prototype version. Number of fragmentation pulses, total fragmentation energies and correlation with the individual stone parameters were determined. The quality of the tissue-detection mode was evaluated in postmortem pancreata. RESULTS The standard STDS detected only 45% of the pancrea…

Assessment of a Modified Acoustic Lens for Electromagnetic Shock Wave Lithotripters in a Swine Model

2013

The acoustic lens of the Modularis electromagnetic shock wave lithotripter (Siemens, Malvern, Pennsylvania) was modified to produce a pressure waveform and focal zone more closely resembling that of the original HM3 device (Dornier Medtech, Wessling, Germany). We assessed the newly designed acoustic lens in vivo in an animal model.Stone fragmentation and tissue injury produced by the original and modified lenses of the Modularis lithotripter were evaluated in a swine model under equivalent acoustic pulse energy (about 45 mJ) at 1 Hz pulse repetition frequency. Stone fragmentation was determined by the weight percent of stone fragments less than 2 mm. To assess tissue injury, shock wave trea…