Shock-wave lithotripsy of gallbladder stones. The first 175 patients

Efficacy of endoscopic trans-papillary gallbladder stenting and drainage in acute calculous cholecystitis in high-risk patients: a systematic review and meta-analysis

Background and aims

Acute calculous cholecystitis (ACC) represents about one-third of all surgical emergencies. The gold standard management of ACC is laparoscopic cholecystectomy. Although cholecystectomy is a safe procedure, it may be dangerous and contraindicated in patients with complex comorbidities. Endoscopic transpapillary gallbladder stenting (ETGBS) and drainage had been widely used to manage patients suffering from ACC with comorbidities.

Methods

We searched PubMed, SCOPUS, Web of Science, and Cochrane Library for relevant studies assessing the use of ETGBS in patients suffering from ACC with various comorbidities. Risk of bias assessment was performed using the National Institues of Health (NIH) tool. We included the following outcomes: clinical success, technical success, late complications, and pancreatitis.

Results

We included seven studies that met our inclusion criteria. We found that the pooled proportion of clinical success, technical success, late complications, and pancreatitis was [91.3%, 95% confidence interval (CI) (86.8%, 95.9%)], [92.8%, 95% CI (89%, 96.5%)], [5.4%, 95% CI (2.9%, 7.9%)], and [3.5%, 95% CI (1.2%, 5.8%)], respectively.

Conclusion

We found that an ETGBS was an effective and well-tolerated method for the treatment of cholecystitis, especially in high-risk individuals.

Experimental and Analytical Study of under Water Pressure Wave Induced by the Implosion of a Bubble Generated by Focused Laser

In various domains of material processing, such as surface cleaning and surface treatment, cavitation phenomenon may become an alternative to traditional methods if this phenomenon is well understood. Due to experimental and mathematical difficulties in theoretical models, it is still a challenge to accurately measure the physical mechanism of the fluid/structure interactions. In this study, we verified the feasibility of using polyvinylidene fluoride (PVDF) sensors to quantitatively measure the under-water pressure wave generated by the collapse of a single cavitation bubble. The electrical signal obtained by PVDF can be converted into pressure information only by using the sensor material parameters provided by the supplier. During the conversion process, only the capacitance of the acquisition chain needs to be additionally measured. At the same time, a high-speed video recording system was used to visualize the evolution of the cavitation bubble. The Gilmore analytical model and an associated wave propagation model were used to simulate the pressure peak of the first collapse of the cavitation bubble. This theoretical pressure was compared with the experimental results. The result showed that, for bubbles with a normalized standoff distance γ larger than 5, the PVDF sensor had the ability to quantitatively measure the pressure wave generated by a single cavitation bubble.

Broadband acoustic subwavelength imaging by rapidly modulated stratified media

An acoustic anisotropic lens (AAL) based on large mass-density modulation depth (LMMD) medium is proposed for subwavelength imaging. The underlying mechanism for converting evanescent components into propagating waves is attributed to the strong suppression of the transverse velocity field component in LMMD medium. In addition, the proposed lens can operate in a broadband manner, which is more flexible in practical applications. Both transfer matrix method and finite element method are used to corroborate the subwavelength imaging capabilities of the proposed lens. The numerical simulations demonstrate that the proposed lens can clearly distinguish two Gaussian sources with equal width of λ₀/25 and separation of λ₀/5 in a broad frequency bandwidth. Medium losses decrease the transmission but cannot compromise the resolution of the lens.

Efficacy of low-intensity shock wave therapy for erectile dysfunction: A systematic review and meta-analysis

CONTEXT

The low-intensity shockwave (LISW) therapy is a recently developed modality for treating erectile dysfunction.

OBJECTIVE

To assess the efficacy of LISW therapy for treating erectile dysfunction as described in the literature.

ACQUISITION OF EVIDENCE

Two independent reviewers identified studies eligible for a systematic review and meta-analysis of various sources written in English and Spanish, using the databases of PubMed, EMBASE and Web of Science. We excluded studies on Peyronie's disease. We employed the DerSimonian-Laird method for defining heterogeneity, calculating the grouped standard deviation of the mean (SDM). The primary objective of this review is to assess efficacy based on the change in the International Index of Erectile Function (IIEF-EF) over baseline at 1 month from the start of treatment, both for the treatment arm and the placebo arm. The secondary objective is focused on analysing IIEF-EF at 3-6 months from the start of the therapy.

SUMMARY OF THE EVIDENCE

The pooled data of 636 patients from 12 studies showed that treatment with LISW resulted in a significant increase in IIEF-EF at 1 month with respect to baseline (SDM, -2.92; P=.000), to a greater degree than placebo (SDM, -.99; P=.000). The IIEF-EF at 3-6 months for the treated patients was significantly greater than baseline (SDM, -2.78; P=.000). Only one study compared the efficacy of placebo at 3-6 months versus baseline (SDM, -9.14). The comparison between LISW and placebo favours active treatment (SDM, 2.53; P=.000) at 1 month. There are insufficient data in the literature to assess the response over placebo at 3-6 months.

CONCLUSIONS

According to the literature, treatment with LISW for erectile dysfunction is effective, both in the short and medium term. LISW has been described as more effective than placebo in the short term. The long-term efficacy data are insufficient. More studies are needed to explain the role of this therapy according to specific causes of erectile dysfunction.

Evidence-based clinical practice guidelines for cholelithiasis 2016

Cholelithiasis is one of the commonest diseases in gastroenterology. Remarkable improvements in therapeutic modalities for cholelithiasis and its complications are evident. The Japanese Society of Gastroenterology has revised the evidence-based clinical practice guidelines for cholelithiasis. Forty-three clinical questions, for four categories-epidemiology and pathogenesis, diagnosis, treatments, and prognosis and complications-were selected, and a literature search was performed for the clinical questions with use of the MEDLINE, Cochrane, and Igaku Chuo Zasshi databases for the period between 1983 and June 2012. The guidelines were developed with use of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. This article preferentially describes the clinical management of cholelithiasis and its complications. Following description of the diagnosis performed stepwise through imaging modalities, treatments of cholecystolithiasis, choledocholithiasis, and hepatolithiasis are introduced along with a flowchart. Since there have been remarkable improvements in endoscopic treatments and surgical techniques, the guidelines ensure flexibility in choices according to the actual clinical environment. The revised clinical practice guidelines are appropriate for use by clinicians in their daily practice.

Percutaneous Rotational Lithotripsy of Gallbladder Stones

Ten patients (aged 39–94 years) with cholecystolithiasis were selected for percutaneous rotational lithotripsy with the Rotolith lithotriptor either because they were considered high-risk patients for cholecystectomy or because they had refused surgery. The procedure was completed in 7 patients. Five of these were stone-free at cholangiography 1 to 2 days after lithotripsy. Conclusive cholangiograms were not obtained in 2 patients due to gallbladder leakage, which in itself did not cause any serious sequelae. At ultrasonography after one month, one of these 2 patients had no visible gallbladder, the other one had small residual gallbladder stones. Rotational lithotripsy is an alternative to cholecystectomy in patients at high surgical risk, especially elderly patients who have undergone cholecystostomy as an emergency treatment for acute cholecystitis.

Chemical Sclerosis of the Gallbladder

Chemical ablation of the gallbladder with absolute ethanol and polidocanol 3% was attempted in 23 and 10 pigs, respectively, after open transhepatic cholecystostomy. Absolute ethanol caused complete necrosis of the gallbladder epithelium in 10 pigs and partial necrosis with focally present gallbladder epithelium in 9. An intact epithelium was observed in 4 pigs but it was not possible to determine whether this epithelium was the original one, not affected by the ethanol, or regenerated after previous damage. Gallbladders with hemorrhage and hydrops were frequently encountered. Gallbladders treated with polidocanol all had an intact epithelium.

Analytic Reviews : Nonsurgical Alternatives in the Management of Gallstones

Until recently, the only therapeutic option for patients with symptomatic gallstones was surgery. However, sev eral new and innovative nonsurgical approaches are cur rently available, including oral dissolution therapy with the bile salts, ursodeoxycholic and chenodeoxycholic acids, instillation of liquid solvents such as methyl tert- butyl ether directly into the gallbladder or the common bile duct, and extracorporeal shock-wave lithotripsy. We review the role of each of these methods in the management of patients with gallstones as well as the epidemiology, pathogenesis, natural history, and radi ological characteristics of gallstones, all important con siderations when choosing appropriate treatment for the individual patient.

Review on Lithotripsy and Cavitation in Urinary Stone Therapy

Cavitation is the sudden formation of vapor bubbles or voids in liquid media and occurs after rapid changes in pressure as a consequence of mechanical forces. It is mostly an undesirable phenomenon. Although the elimination of cavitation is a major topic in the study of fluid dynamics, its destructive nature could be exploited for therapeutic applications. Ultrasonic and hydrodynamic sources are two main origins for generating cavitation. The purpose of this review is to give the reader a general idea about the formation of cavitation phenomenon and existing biomedical applications of ultrasonic and hydrodynamic cavitation. Because of the high number of the studies on ultrasound cavitation in the literature, the main focus of this review is placed on the lithotripsy techniques, which have been widely used for the treatment of urinary stones. Accordingly, cavitation phenomenon and its basic concepts are presented in Section II. The significance of the ultrasound cavitation in the urinary stone treatment is discussed in Section III in detail and hydrodynamic cavitation as an important alternative for the ultrasound cavitation is included in Section IV. Finally, side effects of using both ultrasound and hydrodynamic cavitation in biomedical applications are presented in Section V.

Ultrasound Transducers

Diagnostic medical ultrasound transducers have evolved through the years and have contributed significantly to improved patient care. This article discusses the history and types of transducers and the elements that have changed over time. There has been a sharp transition from natural to human-made elements and from one to many in a single transducer. Ergonomics also now plays a role in transducer design and will continue to do so; the grip, weight, and size of transducers are in the forefront of design considerations. The evolution of transducers has changed not only how well we visualize anatomy and what anatomy we see but also how the patient’s care is managed. Different, new, and emerging technologies certainly will continue to be identified within the sonography community.

Towards a dosimetric framework for therapeutic ultrasound

There is a need for a coherent set of exposure and dose quantities to describe ultrasound fields in media other than water (including tissue and tissue-simulating materials). This paper proposes an outline dosimetry scheme, with quantities for free field exposure, in situ exposure, dose (both instantaneous and cumulative) and effect, to act as a structure for organising a more complete set of definitions. It also presents findings from a survey of the views of the therapeutic ultrasound community which generally supports the principle of using modified free field quantities to describe the in situ field, and the prioritising of dose quantities which are related to heating and thermal mechanisms. Although there is no one-to-one relationship between any known ultrasound dose quantity and a specific biological effect, this can also be said of radiotherapy and other modalities where weighting factors have been developed to calculate the degree of equivalence between different tissues and radiation types. This same separation is recommended for ultrasound, provided that an appropriate set of recognised 'engineering' quantities can be established for exposure and dose quantities.

Design of micromachined self-focusing piezoelectric composite ultrasound transducer

Based on the Fresnel half-wave band interference, a micromachined self-focusing piezoelectric composite ultrasound transducer was proposed in this paper. The theoretical analysis was deduced based on the concept of constructive interference of acoustic waves and electromechanical response of piezoelectric composites. The calculated and simulation results showed that it combined the advantages of composite transducer and plate self-focusing transducer, and can achieve high electromechanical coupling coefficient, low acoustic impedance, high intensity, short focal length and micro size. Because it was based on the micro-electromechanical systems, the fabrication process was accurate and controllable, which made it have good potential for interventional ultrasound imaging, cellular microstructure imaging, skin cancer detection and industrial nondestructive testing applications.

Can low-intensity extracorporeal shockwave therapy improve erectile dysfunction? A prospective, randomized, double-blind, placebo-controlled study

OBJECTIVE

The aim of this study was to investigate whether low-intensity extracorporeal shockwave therapy (LI-ESWT) can be used as a treatment for men with erectile dysfunction of organic origin.

MATERIALS AND METHODS

This prospective, randomized, blinded, placebo-controlled study included 112 men unable to have intercourse either with or without medication. Erectile dysfunction was assessed at screening and 5, 12 and 24 weeks after treatment. Assessment was performed by interview and using the Erection Hardness Scale (EHS) and the International Index of Erectile Function (IIEF-15) questionnaire. The men were randomly assigned either to LI-ESWT (n = 51, active group) or placebo (n = 54, placebo group). They received five treatments over 5 weeks. Both the participants and the doctors were blinded to the treatment. After 10 weeks, the placebo group received active treatment (active placebo group).

RESULTS

Twenty-nine men (57%, active group) were able to obtain an erection after treatment and to have sexual intercourse without the use of medication. In the placebo group, only five men (9%) showed similar results (p = 0.0001). The EHS after 5 weeks showed that men in the active group experienced a significant improvement in their erectile dysfunction, but no significant result was found with the use of the IIEF - Erectile Function domain.

CONCLUSIONS

This placebo-controlled study over 5 weeks shows that 57% of the men who suffered from erectile dysfunction had an effect from LI-ESWT. After 24 weeks, seven (19%, active group) and nine (23%, active placebo group) men were still able to have intercourse without medication. This study shows a possible cure in some patients, but more research, longer follow-up in the placebo group and an international multicentre randomized study are needed.

Anisotropic metamaterials for full control of acoustic waves

We study a class of acoustic metamaterials formed by layers of perforated plates and producing negative refraction and backward propagation of sound. A slab of such material is shown to act as a perfect acoustic lens, yielding images with subwavelength resolution over large distances. Our study constitutes a nontrivial extension of similar concepts from optics to acoustics, capable of sustaining negative refraction over extended angular ranges, with potential application to enhanced imaging for medical and detection purposes, acoustofluidics, and sonochemistry.

Biliary physiology and disease: reflections of a physician-scientist

A review is presented of Gustav Paumgartner's five decades of research and practice in hepatology focusing on biliary physiology and disease. It begins with studies of the excretory function of the liver including hepatic uptake of indocyanine green, bilirubin, and bile acids. The implications of these studies for diagnosis and understanding of liver diseases are pointed out. From there, the path of scientific research leads to investigations of hepatobiliary bile acid transport and the major mechanisms of bile formation. The therapeutic effects of the hydrophilic bile acid, ursodeoxycholic acid, have greatly stimulated these studies. Although ursodeoxycholic acid therapy for dissolution of cholesterol gallstones and some other nonsurgical treatments of gallstones were largely superseded by surgical techniques, ursodeoxycholic acid is currently considered the mainstay of therapy of some chronic cholestatic liver diseases, such as primary biliary cirrhosis. The major mechanisms of action of ursodeoxycholic acid therapy in cholestatic liver diseases are discussed. An attempt is made to illustrate how scientific research can lead to advances in medical practice that help patients.

Endoscopic treatment of biliary tract disease prior to orthotopic liver transplantation

Endoscopic therapy for biliary tract disease in patients with end-stage liver disease (ESLD) before liver transplantation is safe and effective. Reported results in patients with choledocholithiasis, primary sclerosing cholangitis (PSC), and symptomatic gallbladder diseases are encouraging. Prompt recognition and appropriate treatment of symptomatic gallbladder and bile duct disease are important in reducing morbidity and mortality in these high-risk patients while they await liver transplantation. Confirmation of tissue diagnosis of cholangiocarcinoma in patients with sclerosing cholangitis is still difficult. Better screening tools and diagnostic methods are necessary for early detection. Because liver transplantation is the only definitive therapy for patients with advanced cirrhosis, maintenance of their candidacy with either endoscopic or radiologic therapeutic interventions is warranted until transplantation. Endoscopic therapy is the preferred method when feasible. If necessary, percutaneous transhepatic biliary drainage (PTBD) is a viable alternative because both avoid the attendant risks of surgery in a high-risk population with advanced liver disease.

Extracorporeal shock wave lithotripsy for the treatment of pancreatic duct stones

The purpose of endoscopic therapy in chronic pancreatitis is to decompress the main pancreatic duct and to remove the obstacles that impede the ductal flow of pancreatic juice. The availability of extracorporeal shock wave lithotripsy (ESWL) has improved the results of endoscopic drainage of the main pancreatic duct and has also expanded the indications of endoscopic therapy for chronic pancreatitis. This article briefly reviews ESWL for pancreatic duct stones in patients with chronic pancreatitis, including our experience with ESWL. ESWL is an effective and safe procedure for endoscopically unremovable main pancreatic duct stones, and, in selected patients, ESWL alone may be effective.

Ten years experience with piezoelectric extracorporeal shockwave lithotripsy of gallbladder stones

BACKGROUND

A critical review of the experience with extracorporeal shockwave lithotripsy (ESWL) of gallbladder stones is needed to clarify whether this method should continue to be applied to patients.

METHODS

Patients with symptomatic gallbladder stones were treated by piezoelectric ESWL according to a prospective protocol between 1988 and 1997. ESWL treatment was limited to a maximum of three (solitary stones <20 mm diameter) to five sessions (larger solitary or multiple stones) and 3000 pulses per session. Univariate and multivariate analyses of pretreatment and treatment variables were performed to investigate their impact on fragmentation efficacy and stone clearance. A tree-based analysis was used to identify prognostically homogenous subgroups of individuals with maximum benefit from ESWL.

RESULTS

Four hundred and eight patients, 76% female and 24% male, with a mean age of 46 (SD, 13) years, were selected for evaluation. Cox regression analysis identified three pretreatment variables with significant prognostic impact: (1) number of gallstones >1 (relative risk, 2.6 (95% CI, 1.9-3.5)), (2) size of stones >17 mm (1.7 (1.4-2.2)), and (3) computed tomography (CT) density of stones >55 Hounsfield units (H) (1.4 (1.1-1.8)). According to tree-based analysis, the stone clearance rate after 1 year was 85% (95% CI, 75-91%) for solitary stones <16 mm, 79% (70-86%) for solitary stones > or =16 mm with a CT density <84 H, 45% (32-55%) for solitary stones > or =16 mm with a CT density > or =84 H, and 42% (30-51%) for multiple stones. Five years after stone clearance, recurrence occurred in 43% of patients (95% CI, 39-47%).

CONCLUSIONS

ESWL treatment showed an acceptable stone clearance in the case of small solitary gallbladder stones (<16 mm) or larger solitary stones with a CT density <84 H, but a very low success rate in the case of multiple stones. The poor long-term success, however, is an important argument against the use of ESWL of gallbladder stones.

Predictions and associations of cholecystectomy in patients with cholecystolithiasis treated with extracorporeal shock wave lithotripsy

Extracorporeal shock wave lithotripsy (ESWL) is effective in the treatment of symptomatic cholecystolithiasis in well-selected patients. We analyzed the predictors of cholecystectomy in a large series of gallstone patients after ESWL. This was a retrospective follow-up cohort-study of consecutive patients undergoing ESWL for symptomatic cholecystolithiasis over a 9-year period. It was possible to analyze a total of 297 patients; there were 211 women and 86 men, with a mean age of 52 years (range, 8-81 years). Patients that had been cholecystectomized after ESWL were compared to patients with their gallbladder still in situ and determinants of cholecystemctomy in terms of clinical, stone, and gallbladder parameters and symptoms analyzed. The mean duration of follow-up was 99 months (range, 27-134 months). During follow-up, 106 (36%) patients underwent a cholecystectomy at a mean of 34 months (range, 0-127 months) after ESWL. Histological data showed a normal gallbladder wall in only 4 cases; 101 examinations revealed some kind of (chronic) inflammation, which was not different from histological gallbladder results in patients without prior lithotripsy. Three gallbladder polyps were found, but no carcinoma. Cholecystectomy after ESWL of gallbladder stones was strongly associated with persitent and/or renewed biliary symtoms. Nevertheless, only three of four patients became asymptomatic after CE. Thus, ESWL proved to be a valuable organ-preserving alternative to cholecystectomy in selected patients.

Extracorporeal Lithotripsy for Salivary Calculi: A Long-Term Clinical Experience

OBJECTIVES/HYPOTHESIS

The objective was to assess in a large series of patients with a long-term clinical follow-up the validity of extracorporeal electromagnetic shock wave lithotripsy as a minimally invasive therapy for sialolithiasis.

STUDY DESIGN

Consecutive patient series.

METHODS

Three hundred twenty-two consecutive symptomatic outpatients with single or multiple calculi in the submandibular (234 patients) or parotid (88 patients) gland underwent a complete extracorporeal electromagnetic shock wave lithotripsy treatment. Treatment results were classified into three groups: successful result with complete ultrasonographic elimination of the stone after lithotripsy, successful result with residual ultrasonographic fragments that were less than 2 mm in diameter, and unsuccessful result with residual ultrasonographic fragments that were greater than 2 mm in diameter. Univariate and multivariate statistical analyses were performed.

RESULTS

Complete elimination of the stone was achieved in 45% of patients. On ultrasonography, residual fragments (<2 mm in diameter) were detected in 27.3% of patients, and persisting fragments greater than 2 mm in diameter were assessed in 27.7% of patients. In 3.1% of patients, all with submandibular gland stones, sialoadenectomy was performed. Recurrence of calculi in the treated gland was observed during a median follow-up period of 57 months in four patients with complete ultrasonographic clearance of the stone occurring 10 to 58 months after lithotripsy. Univariate analysis showed that a favorable treatment result was significantly associated with the younger age of the patients (< or = 46 y), parotid and intraductal localization of the stone, diameter of the stone (< or = 7 mm), and number of therapeutic sessions (< or = 6). On multivariate analysis, the age of the patient, parotid site of the stone, stone diameter, number of therapeutic sessions, and number of shock waves were associated with favorable outcome.

CONCLUSION

Extracorporeal electromagnetic shock wave lithotripsy is to be considered an efficient, minimally invasive treatment modality for salivary calculi.

Approach to idiopathic recurrent pancreatitis

Acute pancreatitis is caused by acute or chronic alcohol intake or choledocholithiasis in approximately 80% of cases. In the absence of alcohol abuse or gallstones, a variety of established and putative factors must be considered, any of which can cause a single or recurrent attacks of acute pancreatitis. When the underlying cause eludes detection following an initial thorough search and leads to a second attack, the term idiopathic acute recurrent pancreatitis (IARP) is applied. This article discusses IARP and its work-up.

Comparison of tree-based methods for prognostic stratification of survival data

Tree-based methods can be used to generate rules for prognostic classification of patients that are expressed as logical combinations of covariate values. Several splitting algorithms have been proposed for generating trees from survival data. However, the choice of an appropriate algorithm is difficult and may also depend on clinical considerations. By means of a prognostic study of patients with gallbladder stones and of a simulation study, we compare the following splitting algorithms: log-rank statistic adjusted for measurement scale with (AP) and without (AU) pruning, exponential log-likelihood loss (EP), Kaplan-Meier (KP) distance of survival curves, unadjusted log-rank statistic (LP), martingale residuals (MP), and node impurity (ZP). With the exception of the AU algorithm (based on a Bonferroni-adjusted p-value driven stopping rule), trees are pruned using the measure of split-complexity, and optimally-sized trees are selected using cross-validation. The integrated Brier score is used for the evaluation of predictive models. According to the results of our simulation study and of the clinical example, we conclude that the AU, AP, EP, and LP algorithm may yield superior predictive accuracy. The choice among these four algorithms may be based on the required parsimonity and on medical considerations.

Extracorporeal shock wave lithotripsy of pancreatic duct stones using the Healthtronics LithoTron lithotriptor and the Dornier HM3 lithotripsy machine

PURPOSE

Pancreatic duct stones, which are most often a result of alcohol induced chronic pancreatitis, can lead to chronic abdominal pain, pseudocysts, and exocrine and endocrine failure of the pancreas. Others have reported success using extracorporeal shock wave lithotripsy (ESWL) (Dornier Medical Systems, Inc., Marietta, Georgia) for pancreatic stones. We report our experience with pancreatic ESWL using the LithoTron (Healthtronics, Marietta, Georgia) and HM3 (Dornier) lithotripsy machines.

MATERIALS AND METHODS

We performed pancreatic ESWL in 23 patients in 4 years, including in 12 with the LithoTron and in 11 with the HM3. After ESWL endoscopic retrograde cholangio-pancreatography (ERCP) was performed in all cases. Stone-free status was defined as no stone fragments visualized or the elimination of all post-ESWL stones by ERCP.

RESULTS

Stone-free status was documented in 83% and 82% of patients treated with the LithoTron and HM3, respectively, and 2 per group later required open surgical intervention. There were no changes in pancreatic enzymes and no cases of sepsis or fever after ERCP.

CONCLUSIONS

In association with post-procedure ERCP pancreatic ESWL is an effective and safe procedure that enables patients with obstructing pancreatic duct stones recalcitrant to primary endoscopic extraction to avoid a potentially morbid open procedure. The HM3 and LithoTron have comparable efficacy and safety. This modality is particularly effective for a stone aggregate of less than 20 mm., while a larger stone burden of greater than 20 mm. in aggregate and multiple stones are clear risk factors for treatment failure.

Absence of apolipoprotein E4 genotype, good gallbladder motility and presence of solitary stones delay rather than prevent gallstone recurrence after extracorporeal shock wave lithotripsy

BACKGROUND/AIMS

Extracorporeal shock wave lithotripsy (ESWL) with adjuvant bile salt dissolution therapy may be successful in selected gallstone patients, but the considerable risk of recurrence is a major drawback. Apolipoprotein E4 genotype and impaired gallbladder motility have been identified as major risk factors for recurrence during short-term follow up. We have now examined their relevance during long-term follow up.

METHODS

Eighty-four cholesterol gallstone patients (55 solitary and 29 multiple (two to ten) stones) were followed prospectively up to 10 years after complete stone disappearance. Various potential risk factors for recurrence were evaluated.

RESULTS

Gallstone recurrence was found in up to 80% of patients at 10 years follow-up. Absence of the apolipoprotein epsilon4 allele, initial solitary stones, good gallbladder emptying (i.e. minimal postprandial volume < or = 6 ml) and 2-year postdissolution ursodeoxycholic acid prophylaxis (in ten patients) all delayed but did not prevent recurrence. In contrast, regular use of non-steroidal anti-inflammatory drugs (NSAIDs) was identified as an independent protective factor, with greatly decreased recurrence (at 10 years: 58 vs 93% in non-NSAID users, P = 0.03).

CONCLUSIONS

Non-apolipoprotein E4 genotype, presence of solitary stones and good gallbladder emptying delay rather than prevent recurrence after initially successful ESWL. Regular use of NSAIDs may prevent recurrence.

Long-term evaluation of extracorporeal shock-wave lithotripsy for cholesterol gallstones

BACKGROUND

Extracorporeal shock-wave lithotripsy (ESWL) is a treatment that preserves the gallbladder. Problems after ESWL treatment include stone recurrence and the development of biliary symptoms.

METHODS

Two hundred and sixty-two patients with cholesterol-type gallstones, the best indication for ESWL treatment, and 42 control patients with cholesterol-type gallstones who received no treatment entered this study. We evaluated the factors associated with recurrence of gallstones after stone clearance and the development of biliary symptoms after ESWL treatment.

RESULTS

The 3-, 5- and 7-year cumulative probabilities of gallstone recurrence were 20.6, 27.1 and 33.1%, respectively, with the recurrence probability significantly lower in patients with good gallbladder contractility. In patients with recurrence, ursodeoxycholic acid (UDCA) treatment was effective. In 69 patients with residual gallstones, the 3-, 5- and 7-year cumulative risks of biliary symptoms were 17.3, 24.9 and 30.5%, respectively. With residual gallstones, the risk of biliary symptoms developing was significantly lower in patients with a < or = 3 mm fragment size at the end of ESWL treatment and in those treated consistently with UDCA for 6 months or more after treatment with ESWL. The risk of biliary symptoms was significantly lower in ESWL-treated patients with residual stones who had a < or = 3 mm fragment size after treatment compared to those of control patients.

CONCLUSIONS

Ursodeoxycholic acid was effective in clearing stones in patients with gallstone recurrence. In patients with residual stones, the fragmentation of stones to < or = 3 mm and UDCA administration effectively reduced the risk of subsequent biliary symptoms.

Applying 'technology assessment' and 'evidence based medicine' theory to interventional radiology. Part 1: Suggestions for the phased evaluation of new procedures

AIM

To compare and contrast interventional radiology (IR) clinical and research practices with the technology assessment and evidence-based medicine (EBM) paradigms and make suggestions for the phased evaluation of new IR procedures.

MATERIALS AND METHODS

Course literature of the Association of University Radiologists' 'Basic Technology Assessment for Radiologists' course and the McMaster University Health Information Research Unit's 'How to Teach Evidence-Based Medicine 1999' course were used to identify major publications in each discipline. A computer search was performed to seek other relevant literature. A model of traditional development of IR procedures was developed. Suggestions for the phased evaluation of IR procedures were derived.

RESULTS

As in diagnostic radiology, several levels of progressively stronger IR study design can be described and related to EBM 'levels of evidence'. These range from case reports and case series through case-control and cohort studies to randomized controlled trials (RCTs). The major weakness in the existing IR literature is the predominance of small, uncontrolled, case series. Randomized controlled trials are likely to provide the best possible evidence of effectiveness. They are expensive and randomization is sometimes unethical or impractical. Case-control and cohort studies have been under-utilized. Evidence-based medicine indices of benefit and harm have not yet been applied in IR and may have clinical advantages over traditional statistical methods. A literature search (10 years) using MeSH terms 'radiology, interventional' and 'efficacy' yielded 30 papers. Combining 'radiology, interventional' and 'evidence-based medicine' yielded no papers. Comparative searches substituting the term 'diagnostic imaging' for 'radiology, interventional' yielded 4883 and 62 papers, respectively.

CONCLUSION

Principles of technology assessment and EBM can be applied to the investigation of new IR procedures. A tool is needed to simplify the application of EBM analytic methods. Better education in research methods is needed to raise the levels of evidence provided by the bulk of IR research and allow new procedures to be introduced into practice appropriately. Malone, D. E. & MacEneaney, P. M. (2000). Clinical Radiology55, 929-937.

Factors affecting gallstone recurrence after successful extracorporeal shock wave lithotripsy

Ninety-six patients treated successively for symptomatic cholelithiasis with extracorporeal shock wave lithotripsy (ESWL) and oral bile acid therapy consisting of ursodeoxycholic acid in daily dosages of 600 mg were prospectively followed for gallstone recurrence for a median of 13 months. Ultrasonography was performed to detect stone recurrence at 3, 6, and 12 months, and then yearly after the termination of therapy. Recurrent stones were found in 17 patients (18%). The cumulative probability of gallstone recurrence was 15.8% at 12 months, 26.1% at 24 months, and 30.7% at 36 months. The probability of stone recurrence over the entire period of observation was not dependent on stone number, whereas the median interval to detection of recurrence was significantly shorter in the patients with multiple stones (2 months) than in those with solitary stones (8 months) (p < 0.05). The rate of impaired gallbladder contractility was higher in patients with recurrence (8/15, 53.3%) when compared with those with no recurrence (15/72, 20.8%) (p < 0.01). Neither age, gender, or stone characteristics predicted stone recurrence. Only one patient with a recurrence reported biliary pain. Of the 15 patients with recurrent stones who opted for further nonsurgical treatment, complete stone disappearance was achieved in 10. Impaired gallbladder function may predict gallstone recurrence after ESWL.

Extracorporeal shock wave lithotripsy of gallstones revisited: current status and future promises

The improvement and refinement of extracorporeal shock wave lithotripsy (ESWL) has made this non-invasive treatment modality not only more effective, but also applicable to a larger population of gallstone patients. It can be performed safely on an outpatient basis. Advances in lithotripsy technology have made it possible to fragment stones into very small, sand-like particles (pulverization), which clear the gall-bladder faster than large fragments. Recent studies provide evidence that adjuvant bile acids may not be necessary in most cases in which pulverization is achieved. Good gall-bladder emptying appears both to promote the clearance of gallstones after ESWL and to decrease their recurrence. Although generally found to be more expensive than surgery if bile acids are used, ESWL should be cost-effective, as bile acids may not be necessary in all patients. Elderly patients with radiolucent, solitary and less than 30 mm gallstones can particularly benefit from lithotripsy.

Endoscopic stenting of the gallbladder for symptomatic gallbladder disease in patients with end-stage liver disease awaiting orthotopic liver transplantation

Cholecystectomy in patients with advanced cirrhosis is associated with excessive morbidity and mortality. Because open cholecystectomy in patients with Child's class C cirrhosis has a reported mortality rate as high as 83%, symptomatic gallbladder disease in patients awaiting orthotopic liver transplantation (OLT) poses a unique clinical problem. The goal of this study is to determine whether the treatment of symptomatic gallbladder disease with endoscopic stenting of the gallbladder effectively reduces biliary symptoms and complications or the need for cholecystectomy. Thirteen patients with symptomatic gallbladder disease with and without cholelithiasis and advanced cirrhosis who were candidates for OLT underwent placement of a biliary stent from the gallbladder to the duodenum at endoscopic retrograde cholangiography. In each patient, biliary symptoms and complications ceased after stent placement. Seven patients underwent successful OLT 1 to 24 months after the procedure. One patient subsequently became a noncandidate for OLT and died of diabetes complications 3 years after the procedure. Five others are awaiting OLT (6 to 28 months postprocedure). One patient had recurrent pericholecystic fluid collection requiring percutaneous drainage and antibiotic therapy 8 months after the procedure. No patient has had recurrent symptoms, and currently all patients are free of complications. None required surgical intervention of the gallbladder or biliary tree. We conclude that endoscopic stenting of the gallbladder is the preferred treatment for symptomatic gallbladder disease in patients with end-stage liver disease awaiting OLT. This approach is noninvasive, safe, and effective in preventing potential morbidity and mortality.

Gallstone recurrence after successful shock wave therapy: the magnitude of the problem and the predictive factors

OBJECTIVE

Reports concerning long term recurrence of gallstones after successful extracorporeal shock wave lithotripsy (ESWL) show a high probability of stone recurrence. There is still discussion on the factors influencing stone recurrence. In this study we wanted to evaluate the long term recurrence of gallstones after stone clearance with ESWL and oral bile acids, and to assess possible risk and preventive factors of stone recurrence.

METHODS

A total of 322 consecutive patients with stone clearance between December 1988 and December 1995 were included. All patients were contacted for ultrasonography and were interviewed for additional information on daily intake of aspirin, NSAIDs, cholesterol lowering medication, estrogen therapy, and biliary pain during follow-up.

RESULTS

A total of 187 patients were still stone-free after a mean follow-up of 35 months (range: 3-89 months); 135 patients had recurrence. There was a significant association between stone recurrence and estrogen intake (p = 0.04), number of lithotripsy sessions (p = 0.0007), time until stone disappearance (p = 0.0003), and biliary pain (p < 0.0001). There was no difference in recurrence rate between solitary and multiple stones.

CONCLUSIONS

Long-term recurrence of gallstones after lithotripsy is high: < or = 69% after 6 yr. We found a significant association of stone recurrence with estrogen intake, number of lithotripsy sessions, and time until stone disappearance. Intake of aspirin or NSAIDs was not associated with decreased stone recurrence. Of the patients with recurrent stones, 57% had biliary pain.

Evaluation of hepatocyte function after extracorporeal shock wave lithotripsy with hepatobiliary scintigraphy

OBJECTIVE

Extra corporeal shock wave lithotripsy is a promising and effective therapy mode in the nonsurgical therapy of gallstones. This prospective study was conducted to investigate the effects of ESWL on hepatocellular function, using quantitative hepatobiliary scintigraphy, serum aminotransferase, alkaline phosphatase (ALP), amylase (AML), and direct and indirect bilirubin levels.

METHODS

The study consisted of 22 patients with ultrasonographically documented gallstones. Hepatobiliary scintigraphy was applied to all patients before ESWL and biochemical tests were performed. Scintigraphy and biochemical tests were repeated in 16 patients 24 h, in seven patients 72 h, and in six patients 1 wk after ESWL. The hepatic extraction fraction (HEF) was calculated using deconvolution analysis of scintigraphic data.

RESULTS

All patients' pre-ESWL biochemical tests and HEF values were within the normal range. The 24- and 72-h post-ESWL aminotransferase, ALP, and AML levels and HEF values were significantly different from pre-ESWL values (p < 0.05). After 1 wk this difference disappeared. Decreased HEF values were observed in 50% of patients 24 h, in 71.7% of patients 72 h, and in 16.6% of patients 1 wk after ESWL. A direct relationship was also observed between the number of shocks applied and the degree of impairment in HEF values.

CONCLUSION

Transient hepatocellular dysfunction, which usually occurs after ESWL, can be demonstrated and monitored using quantitative hepatobiliary scintigraphy.

[Changes in and acceptance of surgical and noninvasive therapy procedures in cholecystolithiasis]

BACKGROUND

The treatment of cholecystolithiasis has changed fundamentally in recent years due to the development of non-surgical techniques (extracorporeal shockwave lithotripsy [ESWL], oral litholysis) and the implementation of laparoscopic cholecystectomy.

PATIENTS AND RESULTS

Retrospective analysis of 2270 patients (1649 women, 621 men; age: 47.2 +/- 14 years) presenting with gallstone disorders in a university medical outpatients department between 1988 and 1992 in order to be instructed as to the most suitable therapy method bear witness to the rapid change in therapeutic procedure. Laparoscopic removal of the gallbladder has virtually supplanted conventional cholecystectomy, and within 5 years the proportionate role of ESWL has declined from 21 to 12%. Over the years, the proportion of patients requiring no therapeutic intervention remained constant (at about 20%). The therapeutic recommendations of the "experts" were implemented in almost 80% of cases. The majority of patients were satisfied with the chosen therapeutic approach (surgery: 93.0%, ESWL: 77.6%), although 44% of ESWL-patients and 36% of surgically managed patients reported complaints which persisted even after completion of therapy. Despite unsuccessful ESWL (residual fragments or recurrent stones) 58/95 (61%) of interviewed patients would again give preference to this non-invasive modality in the event of a renewed therapeutic decision.

CONCLUSION

Only a few years after its introduction, laparoscopic cholecystectomy has asserted itself as the predominant treatment option. But as far as acceptance and preference by the patient are concerned extracorporeal shockwave lithotripsy--as a non-invasive treatment modality--also enjoys high popularity and can be recommended as an alternative to surgery in suitable patients chosen according to the currently established stringent selection criteria.

Costs and effectiveness of extracorporeal gallbladder stone shock wave lithotripsy versus laparoscopic cholecystectomy. A randomized clinical trial. McGill Gallstone Treatment Group

Thirty-five patients were randomized to extracorporeal shock-wave lithotripsy (ESWL) and 25 to laparoscopic cholecystectomy (LC). Stone disappearance occurred in only 12 of 32 ESWL patients [38% (95% CI: 21-56%)] during a 15-month follow-up. Greater incremental gains in quality of life after 6 months were observed among LC patients (p < .01). Total duration of disability was 6.8 +/- 8.5 days for ESWL, and 22.7 +/- 16.6 days for LC (p < .01). Nine (28%) patients crossed over electively to the LC group, but only 44% of these underwent LC within the next 3 years. ESWL cost Can $58.9/ day of disability saved. ESWL is limited by its selective applicability and modest stone disappearance rate. Its cost-effectiveness is largely dependent on patient acceptance of recurrent episodes of biliary colic due to the persistence of stone fragments.

Extracorporeal shock wave lithotripsy of pancreatic stones in chronic pancreatitis: immediate and medium-term results

BACKGROUND

Obstruction of the main pancreatic duct with upstream hypertension and dilation is a cause of pain in patients with chronic pancreatitis. Pancreatic ductal drainage can be achieved endoscopically by intraductal stone removal after endoscopic pancreatic sphincterotomy and/or by insertion of a pancreatic stent. Extracorporeal shock wave lithotripsy may be needed whenever stones cannot be removed by endoscopic procedures. We present our results in 35 patients treated with a combined endoscopic-extracorporeal shock wave lithotripsy approach with at least 6 months of follow-up.

METHODS

Thirty-five patients with severe chronic pancreatitis were treated by extracorporeal shock wave lithotripsy for endoscopically unretrievable obstructive stones. Extracorporeal shock wave lithotripsy was performed with an electromagnetic lithotriptor in 29 patients and an electrohydraulic lithotriptor in 6.

RESULTS

The procedures were well tolerated by the majority of patients. Fragmentation of stones was obtained in all cases while complete clearance and decompression of pancreatic duct were obtained in 26 of 35 (74.3%) and in 30 of 35 (85.7%) cases, respectively. There was no mortality related to the procedure. Morbidity was observed in 8 of 35 patients (22.8%).

CONCLUSIONS

Extracorporeal shock wave lithotripsy is a safe and effective treatment for endoscopically unretrievable pancreatic stones in the main pancreatic duct. Extracorporeal shock wave lithotripsy should be considered complementary and not an alternative to endoscopic drainage. Combined with endoscopy, extracorporeal shock wave lithotripsy may increase the success rate of nonsurgical treatment of patients with chronic pancreatitis.

Ultrastructure of cholesterol gallstones as observed by electron microscopy after freeze-fracturing

The ultrastructure of cholesterol gallstones (mixed type) was studied in detail for the first time under the transmission electron microscope after freeze-fracturing. Gallstones consisted essentially of cholesterol crystals, some impurities, and fluid. In accord with the theoretical 3.4 nm bilayered structure of cholesterol crystals, 3-4 nm periodicity of crystal layering was observed. However, gallstone cholesterol crystals were not perfect and often showed structural defects. Between crystals, complete edge-to-surface, edge-to-edge and surface-to-surface adhesions, and overall block-like aggregations were found. These may represent the structural basis for the stability of cholesterol crystal aggregation. The easy breakdown of cholesterol gallstones by extracorporeal shock wave lithotripsy is discussed in relation to their ultrastructure.

ESWL experience in the therapy of difficult bile duct stones

In recent years, alternatives to surgery for difficult bile duct stones have been developed. Routine endoscopy fails in about 10% of patients. To verify the role of extracorporeal shock wave lithotripsy in residual CBD stones, we treated 32 patients by HM4 or MPL 9000 Dornier lithotripters. Ten (34.4%) patients needed two extracorporeal shock wave lithotripsy sessions, and 3 (10.3%) patients three. Complete clearance was achieved in 29 patients (90.6%) after one or more sessions either by endoscopic (20 pts) or percutaneous (9 pts) extraction of the debris; of the remaining 3 patients, in 2 a bilioduodenal stent was placed and in 1 electrohydraulic lithotripsy was performed. Eighteen and seven-tenths percent transient mild hemobilia, 12.5% microhematuria, and no mortality were observed. It is possible to state that in site- or size-related difficult biliary stones, extracorporeal shock wave lithotripsy is a rapid, safe, and highly effective treatment as an additional nonoperative option to resolve the failure of routine endoscopic measures.

Percutaneous transhepatic endoscopic electrohydraulic lithotripsy of biliary tract calculi after orthotopic liver transplantation

The development of biliary tract calculi after orthotopic liver transplantation presents a unique clinical problem. Previously described techniques for removing biliary stones by shock wave lithotripsy, litholytic therapy with oral bile acids, and endoscopic mechanical extraction may be ineffective or contraindicated in liver transplant patients. For this reason, percutaneous transhepatic electrohydraulic lithotripsy (EHL) was performed using an 11 French flexible ureteroscope in two pediatric patients who developed biliary tract calculi following orthotopic liver transplant. There were no complications and postoperative follow-up over 4 years has been uneventful. To our knowledge, these represent the first reported cases of percutaneous transhepatic endoscopic EHL to fragment biliary tract stones in a transplanted liver, which for us has been a safe and effective therapeutic option.

Treatment of gallstones in the 1990s

Gallstone disease continues to be one of the more common abdominal problems that prompts medical evaluation, particularly in the elderly population. The presentation is diverse, and the treatment options varied. Primary care physicians need to be familiar with the differential diagnosis, evaluation, and therapeutic options available. LC has emerged as the preferred treatment for patients with symptomatic gallstone disease.

Why laparoscopic cholecystectomy today?

Traditional open cholecystectomy became the "gold standard" of surgical treatment for symptomatic gallstone disease during the last century. In spite of its good results, clinicians have been trying to establish effective nonsurgical methods of eliminating gallstones. Although oral, percutaneous, or retrograde litholysis can be used effectively for cholesterol stones, these represent only 10% of all gallstones. Moreover, intracorporeal lithotripsy is an invasive method, and while extracorporeal shock wave lithotripsy is a promising procedure, even after careful selection, only 70%-80% of the patients become stone-free within 1 year. In fact, none of the methods which leave the gallbladder intact are free of complications, and they are followed by 50% stone recurrence within 5 years. Since 1987, laparoscopic cholecystectomy has become the procedure of choice as it is safe and only minimally invasive. We believe that the laparoscopic technique is a promising way to the surgery of the future.

The influence of high-energy shock waves on the development of metastases

The hypothesis that exposure of a solid tumor to high-energy shock waves (HESW) could lead to an increase of metastases was investigated in an animal model. The highly metastatic AT-6 Dunning R3327 rat prostate cancer subline was implanted in the hind limb of a Fisher-Copenhagen rat and was exposed to 6000 shock waves delivered by an experimental lithotripter, or sham-treated, as soon as the tumor had reached a volume of 175-225 mm3. The tumor-bearing leg was amputated 24 h later and the number of metastases was examined 12 weeks thereafter at autopsy. Metastases were seen in 82% of the animals exposed to HESW and in 25% of the sham-treated animals. There was no significant difference in weight of the lungs that contained metastases, between sham and treated animals. These results were confirmed in a second experiment. We conclude that the metastatic spread of tumors with a high metastatic potential may be enhanced by shock-wave exposure.