The Journal of stone disease最新文献

Sixty-eight patients with radiopaque gallbladder stones (38 with a single stone, 30 with multiple stones) were treated with piezoelectric extracorporeal shock wave lithotripsy (ESWL) and results were compared with those of 69 patients with radiolucent stones (28 with a single stone, 41 with multiple stones). Stones were fragmented to 4 mm or less in 76.8% after 41,466 +/- 36,504 shock waves in the radiolucent stone group and 77.9% after 54,686 +/- 51,024 shock waves in the radiopaque stone group (p = 0.876 and 0.130, respectively). In 137 patients, ten patients were lost to follow-up. Average period of follow-up was 220 +/- 198 days. Six-month clearance rate of the radiolucent stone group was 43.5% and that of the radiopaque stone group was 16.4% (p less than 0.05) Figure 1. Six-month clearance rate of patients with single stones smaller than 2 cm was also significantly higher in the radiolucent stone group than in the radiopaque stone group (69.5% vs 18.6%; p less than 0.01). However, in patients with multiple stones, the presence of calcification did not affect rates of successful fragmentation or 6-month clearance. There was no statistically significant difference in incidence of complications between the radiolucent and radiopaque stone groups. Although the number of cases are small and the follow-up period is short, our results of ESWL on radiopaque gallstones are so far not satisfactory in terms of stone clearance. Strict patient selection is needed unless there is an improvement in the lithotripsy procedure or post-lithotripsy management.

Extracorporeal shock wave lithotripsy (ESWL) was introduced as a nonsurgical treatment for uncomplicated, symptomatic gallstone disease. Due to its limited results and the possibility of stone recurrence, ESWL is mainly indicated for patients who reject or cannot tolerate cholecystectomy. For budgetary and planning purposes, it is essential to know what percentage of patients are eligible for this form of therapy. In the literature suitability is either reported variably (ranging from 10% to 53%) or not mentioned. We respectively assessed eligibility for ESWL for different entry criteria, based on the histories of 694 consecutive patients, who were referred for gallstone therapy from April 1, 1988 to October 1, 1991. Only 10.3%-46.9% of symptomatic patients were found eligible for ESWL, depending on the entry criteria used. When the overall results are compared with eligibility, there is no inverse relationship. This suggests that patient selection is not the only factor determining the results of therapy. It is concluded, therefore, that other factors, such as treatment schemes, the lithotripters used, and experience of the treating physicians, are important factors for the outcome of ESWL therapy.

This article presents the design of a newly developed wideband, quantitative shock wave sensor (hydrophone) made of piezoelectric material polyvinylidene difluoride (PVDF). The novel aspects of this device include a disposable sensor element to reduce the per shot costs, and a self-monitoring feature that informs the user that the sensor needs to be replaced. The development, design, and use of the sensors are presented. Results indicate that these sensors can fulfill the requirements for accurate, wideband measurement of lithotripter fields, suitable for quantitative biophysical research or Food and Drug Administration submissions. The disposable feature of the hydrophone system makes the system cost effective for research, quality assurance, and regulatory submissions.

The relationship between acoustic energy, stone burden, and stone clearance in biliary extracorporeal shock wave therapy (ESWL) is unclear. We hypothesized that there is a consistent relationship between these parameters that enables gallstone clearance to be predicted. Using a porcine model and various gallstone burdens, we performed biliary ESWL with varying energy levels and number of shock waves. The acoustic energy/stone burden ratio (AE/SB) was calculated that incorporated these variables. Stone clearance increased with higher energy settings and fewer stones present (p less than 0.005). The relationship between AE/SB ratio and stone clearance was logarithmic (r 2 = 0.82). The plateau of this curve showed optimal stone clearance at approximately 20 joules/g, beyond which point the benefit of further ESWL may not outweigh the risks. This relationship between AE/SB ratio and stone clearance may be able to predict the optimal energy required and probable outcome of biliary ESWL prior to the procedure.

From 40 sets of five human gallstones obtained at cholecystectomy, four stones were subjected to either 125/250 (maximum generator output) or 250/500 (half maximum generator output) electromagnetic shock waves (treatments I/II and III/IV, respectively); the fifth stone was used for computed tomography (CT) and chemical analysis. Overall, 130 (81%) of 160 stones fragmented, including 72 (45%) adequately (fragments less than or equal to 5 mm). For the treatments I, II, III, and IV the overall fragmentation rates were 80%, 95%, 70%, and 80%, respectively. The corresponding percentages of adequate fragmentation ( less than or equal to 5 mm) were 38%, 70%, 30%, and 42%, respectively. The best results were thus obtained after application of 250 shock waves (maximum generator output; treatment II). Pure cholesterol stones (p less than 0.01), stones with a mean CT density less than or equal to 110 HU (p less than 0.001), and stones with a calcified rim (p < 0.05) fragmented significantly better, but adequate fragmentation ( less than or equal to 5 mm) was significantly determined by stone weight and diameter (p less than 0.001), bilirubin content (p less than 0.02), and calcium content (p less than 0.05). A weight greater than 500 mg and a diameter > 10 mm could be defined as stone characteristics with significant negative predictors of adequate fragmentation. However, because the experimental conditions in this in vitro study did not completely simulate clinical settings for various reasons, these observations must be interpreted accordingly.(ABSTRACT TRUNCATED AT 250 WORDS)

The success of extracorporeal shock wave lithotripsy (ESWL) for gallstone elimination is dependent on the lithotripter's ability to reduce the stone to fragments less than 5 mm in diameter, but wide variation in successful fragmentation rates have been reported even with the same instrument. This variation is probably due in part to differences in stone composition. Tsuchiya et al. have recently related the pre-operative ultrasound properties of gallstones to their chemical compositions. In the present study, 138 patients with cholecystolithiasis were treated with ESWL and results were evaluated in light of the pre-treatment sonogram patterns as classified by the aforementioned authors. Complete fragmentation (CF), i.e., fragments less than 5 mm, was achieved in 90% of patients with type I a patterns (pure cholesterol stones); stone number, diameter, and volume had no effects on fragmentation. Significantly lower CF rates were obtained with I b and I c (mixed cholesterol), and type II (combination) stones (p less than 0.0003). No fragmentation at all was achieved in the six stones with type III (bilirubinate) patterns. Twelve months after treatment, 45%, 25%, and 9% of the patients with type 1 a, type I b, and types I c or II (the latter two combined), respectively, were stone-free. Pure and mixed cholesterol gallstones without calcification seem to respond best to ESWL; effective treatment can be expected even when stones are numerous (4-10) or large ( greater than 35 mm). We recommend the inclusion of ultrasound properties of gallstones in the selection criteria for candidates for ESWL.

Intracorporal lithotripsy has gathered momentum in the management of gallstone disease due to the increasing sophistication of technical equipment for the percutaneous, as well as the retrograde-endoscopic route. Laser-induced shock wave lithotripsy (LISL) and electrohydraulic lithotripsy (EHL) have proved feasible by allowing reliable fragmentation of biliary calculi. Evaluation of therapeutic risks, e.g., effects of accidental irradiation of the gallbladder wall, has been performed in small sample sizes only. We investigated the effects of LISL and EHL on multiple sets of human and porcine gallbladders under in vitro conditions. Gallbladders were freshly harvested, mounted, and immersed in different mediums (normal saline, blood, bile). They were swiftly exposed to LISL (Pulsolith¿) and EHL (Lithotron EL 23¿) under differing experimental conditions (energy setting, pulse mode, exposition time, medium, probe pressure) and subjected to standard procedures for morphometric evaluation (Bioquant¿). Tissue effects were described by the depth (d) and width (w) of the cratered lesions, as well as the extension of the damage in the surrounding tissue(s). Serial cuts of the exposed areas yielded 894 section for morphometric analysis. Multivariate analysis of variance (MANOVA) revealed a significant effect of laser energy (p[d] less than 0.002, p[w] < 0.05, p[s] < 0.05), medium (p[d] less than 0.03, p[w] < 0.001, p[s] < 0.04, and exposition time (p[d] less than 0.001, p[s] < 0.001) on the degree of tissue lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

Extracorporeal shock wave lithotripsy and percutaneous nephrostolithotomy have become widely used technologies for removal of urinary calculi, despite a lack of adequate evaluative studies. The possibility of long-term adverse effects of these treatments has been raised, particularly an increase in stone recurrence and development of hypertension following extracorporeal shock wave lithotripsy. We conducted a retrospective study of 1,000 patients treated with extracorporeal shock wave lithotripsy or percutaneous nephrostolithotomy for upper tract stone disease to assess immediate effectiveness and complications, with prospective follow-up to assess stone recurrence and development of hypertension. The effectiveness of each treatment (defined in terms of patients rendered stone-free or having only fragments at discharge) was similar for most stone types. While stone recurrence rates in the first 2 years after treatment were similar in the two groups, cumulative recurrence at 3 years was higher following extracorporeal shock wave lithotripsy compared to percutaneous nephrostolithotomy (39% vs. 23%, p = 0.04). However, logistic regression and Kaplan-Meier analyses showed no significant difference in clinically evident recurrence for patients treated with extracorporeal shock wave lithotripsy. Cumulative incidence of clinically evident stone recurrence did not differ significantly between patients with fragments at discharge (20%) and patients rendered stone-free (15%) (p = 0.24). There was no difference in the development of new hypertension requiring medical treatment. Our findings indicate that extracorporeal shock wave lithotripsy is effective and associated with lower short-term morbidity than percutaneous nephrostolithotomy. Stone fragments left behind by lithotripsy do not appear to confer significant risk of early stone recurrence. Further study is necessary to define long-term risk of recurrence following extracorporeal shock wave lithotripsy.