Extracorporeal shock wave lithotripsy of large difficult common bile duct stones: efficacy and analysis of factors that favor stone fragmentation

Cracking Difficult Biliary Stones

Apart from difficult biliary cannulation, biliary stone removal is considered one of the hurdles in endoscopic retrograde cholangiopancreatography. Generally, simple common bile duct (CBD) stones can be removed either with an extraction balloon or a basket. However, there are difficult stones that cannot be removed using these standard methods. The most difficult stones are large CBD stones and impacted stones in a tapering CBD. A few decades ago, mechanical lithotripsy was usually required to manage these stones. At present, endoscopic papillary large balloon dilation (EPLBD) of the biliary orifice has become the gold standard for large CBD stones up to 1.5 cm. EPLBD can reduce the procedural time by shortening the stone removal process. It can also save the cost of the devices, especially multiple baskets, used in mechanical lithotripsy. Unfortunately, very large CBD stones, stones impacted in a tapering CBD, and some intrahepatic duct stones still require lithotripsy. Peroral cholangioscopy provides direct visualization of the stone, which helps the endoscopist perform a probe-based lithotripsy either with an electrohydraulic probe or a laser probe. This technique can facilitate the management of difficult CBD stones with a high success rate and save procedural time without significant technical complications.

Reviewing the evidence for shockwave- and cell-based regenerative therapies in the treatment of erectile dysfunction

Erectile dysfunction (ED) is both a common and complex disease process. Existing ED treatments do not always achieve adequate results. There is clinical interest in employing regenerative therapies, including low-intensity extracorporeal shockwave therapy (Li-ESWT), platelet rich plasma (PRP), and stem cell therapy (SCT), in the treatment of ED as adjunct or alternative treatments. Here, we present evidence for emerging shockwave- and cell-based regenerative therapies for the treatment of ED following a thorough review of the existing PubMed literature pertaining to Li-ESWT, PRP, and SCT in relation to the treatment of ED. Li-ESWT causes microtrauma in tissue that hypothetically upregulates angiogenesis and recruits stem cells. Several large-scale systematic reviews and meta-analyses have reported that Li-ESWT improved ED in humans. Additionally, evidence has commenced to show that Li-ESWT may be effective against two recognized and complex etiologies of ED: diabetic and neurogenic. PRP delivers an autologous sample rich in growth factors to damaged tissue. Animal model studies have demonstrated improved erectile function recovery as well as preservation of cavernous nerve axons. Studies with PRP in humans are limited. SCT utilizes the regenerative potential of stem cells for healing of damaged tissue. In the treatment of ED, SCT has been used in the setting of diabetic and post-prostatectomy ED. Results of human studies are varied, although SCT treatments did result in increased erectile rigidity with some patients recovering the ability to achieve penetration. While these regenerative therapies show potential to augment the current treatment regimen for ED, there is a paucity of evidence to support the safety and efficacy of these treatments. Further research is necessary to define the role of these alternative therapies in the treatment of ED.

Ductal stones recurrence after extracorporeal shock wave lithotripsy for difficult common bile duct stones: Predictive factors

BACKGROUND & PURPOSE

Extra-corporeal shock wave lithotripsy (ESWL) can be considered in difficult common bile duct stones (DCBDS), with a success rate greater than 90% but data on stone recurrence after ESWL are limited. We performed a retrospective analysis to evaluate long-term outcomes in patients who underwent ESWL for DCBDS.

METHODS

From May 1992 to October 2012, patients who underwent ESWL treatment for DCBDS, not amenable to endoscopic extraction, were included. Data on long-term outcome were collected through phone interviews and medical records.

RESULTS

A total of 201 patients with a successful clearance of DCBDS after ESWL were included. During a median follow-up period of 4.64 years, 40 patients (20%) developed a recurrence of bile duct stones. Logistic regression analysis showed that the common bile duct diameter, gallstones presence and the maximum stone size were significantly associated with recurrence.

CONCLUSIONS

We observed a recurrence rate of 20% over a median follow-up of 4 years. Gallbladder stones, stone size and a dilated common bile duct diameter are risk factors for recurrent stone formation, while ursodeoxycholic acid treatment did not influence recurrence in our population.

Outcome of a session of extracorporeal shock wave lithotripsy before endoscopic retrograde cholangiopancreatography for problematic and large common bile duct stones

AIM

To compare the efficacy of a session of extracorporeal shock wave lithotripsy (ESWL) before endoscopic retrograde cholangiopancreatography (ERCP) vs ERCP only for problematic and large common bile duct (CBD) stones.

METHODS

Adult patients with CBD stones for whom initial ERCP was unsuccessful because of the large size of CBD stones were identified. The patients were randomized into two groups, an “ESWL + ERCP group” and an “ERCP-only” group. For ESWL + ERCP cases, ESWL was performed prior to ERCP. Clearance of the CBD, complications related to the ESWL/ERCP procedure, frequency of mechanical lithotripsy use and duration of the ERCP procedure were evaluated in both groups.

RESULTS

There was no significant difference in baseline characteristics between the two groups. A session of ESWL before ERCP compared with ERCP only resulted in similar outcomes in terms of successful stone removal within the first treatment session (74.2% vs 71.0%, P = 0.135), but a higher clearance rate within the second treatment session (84.4% vs 51.6%, P = 0.018) and total stone clearance (96.0% vs 86.0%, P = 0.029). Moreover, ESWL prior to ERCP not only reduced ERCP procedure time (43 ± 21 min vs 59 ± 28 min, P = 0.034) and the rate of mechanical lithotripsy use (20% vs 30%, P = 0.025), but also raised the clearance rate of extremely large stones (80.0% vs 40.0%, P = 0.016). Post-ERCP complications were similar for the two groups.

CONCLUSION

Based on the higher rate of successful stone removal and minimal complications, ESWL prior to ERCP appears to be a safe and effective treatment for the endoscopic removal of problematic and large CBD stones.

Time-Resolved Laser-Induced Fluorescence Spectroscopy as a Guidance Tool for Laser Lithotripsy of Gallbladder Stones

BACKGROUND AND OBJECTIVES

Although laser lithotripsy for fragmentation of gallbladder stones has been applied successfully in many clinical situations, this approach has two major limitations: (1) the potential to damage or perforate the bile duct and (2) the efficiency can be affected by the chemical composition of the gallstones. The present study evaluated the use of time-resolved laser-induced fluorescence spectroscopy to classify stone types and distinguish stone from tissue.

MATERIALS AND METHODS

Ex vivo time-resolved laser-induced fluorescence analysis (excitation wavelength λ_ex = 400 nm and emission wavelength = 450-700 nm) of 54 gallbladder stones and seven gallbladder tissue samples was conducted. The spectral and temporal parameters were analyzed using linear discrimination analysis (LDA) to differentiate stone from tissue and to classify different stone types using two wavelength regions (λ₁ = 510-530 nm and λ₂ = 550-570 nm).

RESULTS

Examination of 54 gallbladder stones and seven gallbladder tissue samples showed a significant difference in spectral- and temporal-derived parameters. The data were classified using LDA, and the overall accuracy was 94.88%, 84.39%, and 85.79% for both spectral and temporal parameters, only spectral parameters, and only temporal parameters, respectively.

CONCLUSIONS

Our findings establish the feasibility of using time-resolved laser-induced fluorescence spectroscopy as a tool to identify gallbladder stone types and as a stone-tissue detection system to improve the effectiveness of laser lithotripsy procedures and reduce the risk of damaging biliary tract tissues.

Cardiac shock-wave therapy in the treatment of coronary artery disease: systematic review and meta-analysis

AIM

To systematically review currently available cardiac shock-wave therapy (CSWT) studies in humans and perform meta-analysis regarding anti-anginal efficacy of CSWT.

METHODS

The Cochrane Controlled Trials Register, Medline, Medscape, Research Gate, Science Direct, and Web of Science databases were explored. In total 39 studies evaluating the efficacy of CSWT in patients with stable angina were identified including single arm, non- and randomized trials. Information on study design, subject's characteristics, clinical data and endpoints were obtained. Assessment of publication risk of bias was performed and heterogeneity across the studies was calculated by using random effects model.

RESULTS

Totally, 1189 patients were included in 39 reviewed studies, with 1006 patients treated with CSWT. The largest patient sample of single arm study consisted of 111 patients. All selected studies demonstrated significant improvement in subjective measures of angina symptoms and/or quality of life, in the majority of studies left ventricular function and myocardial perfusion improved. In 12 controlled studies with 483 patients included (183 controls) angina class, Seattle Angina Questionnaire (SAQ) score, nitrates consumption were significantly improved after the treatment. In 593 participants across 22 studies the exercise capacity was significantly improved after CSWT, as compared with the baseline values (in meta-analysis standardized mean difference SMD = -0.74; 95% CI, -0.97 to -0.5; p < 0.001).

CONCLUSIONS

Systematic review of CSWT studies in stable coronary artery disease (CAD) demonstrated consistent improvement of clinical variables. Meta-analysis showed a moderate improvement of exercise capacity. Overall, CSWT is a promising non-invasive option for patients with end-stage CAD, but evidence is limited to small sample single-center studies. Multi-center adequately powered randomised double blind studies are warranted.

Pancreatoscopy-Directed Electrohydraulic Lithotripsy for Pancreatic Ductal Stones in Painful Chronic Pancreatitis Using SpyGlass

OBJECTIVE

Painful chronic pancreatitis is often associated with main duct obstruction due to stones. Approaches to management are challenging, including surgery, extracorporeal shock wave lithotripsy, or endoscopic approaches. Here, we report our experience of pancreatoscopy + electrohydraulic lithotripsy (EHL) for pancreatic duct (PD) stones using SpyGlass.

METHODS

We retrospectively audited the use of SpyGlass (Legacy and DS) + EHL. Indication, procedural details, and clinical outcomes were assessed.

RESULTS

A total of 118 SpyGlass + EHL procedures for stones were performed, of which 8 (7%) for pancreatic stones, in 6 patients (3 female; mean [standard deviation] age, 45 [7] years). All patients had painful chronic pancreatitis, with radiological evidence of a dilated PD, and main duct stone disease. Surgical options had been considered in all cases. Stone fragmentation and PD decompression were achieved in 83% (n = 5) without complications. Two patients required 2 EHL procedures to achieve clearance. In 1 patient with failed clearance, pancreatoscopy revealed a stone in the adjacent parenchyma and not in PD. All patients with successful EHL had pain relief/marked improvement at clinical review (mean [standard deviation] follow-up, 2.7 [1.1] years).

CONCLUSIONS

Pancreatoscopy + EHL may have a valuable role in treating obstructing PD stones, possibly avoiding the need for surgery in some patients.

Surgical treatment of incarcerated calculi via laparoscopic bile duct exploration using laparotomy biliary lithotomy forceps

The present study aimed to investigate the practicability and clinical value of applying laparotomy biliary lithotomy forceps to laparoscopic bile duct exploration (LCBDE) for the surgical treatment of incarcerated calculi. A total of 63 patients were diagnosed with cholecystolithiasis and choledocholithiasis. The present study performed a retrospective analysis of clinical samples from 16 of these patients who had incarcerated calculi at the terminus of the common bile duct, and who had been treated with laparoscopic cholecystectomy and LCBDE. During the procedure, laparotomy biliary lithotomy forceps were used to gently remove the calculi from the common bile duct. Of the surgical procedures that used laparotomy biliary lithotomy forceps, one case was unsuccessful and 15 cases were successful. The results of the present study suggested that it may be clinically advisable to use laparotomy biliary lithotomy forceps to remove incarcerated calculi from the common bile duct during a laparoscopy, since it is easy, economical and effective.

Extracorporeal shock wave lithotripsy for difficult common bile duct stones: a comparison between 2 different lithotripters in a large cohort of patients

BACKGROUND

Extracorporeal shock wave lithotripsy (ESWL) for difficult common bile duct (CBD) stones is a safe and effective treatment strategy allowing for bile duct clearance in approximately 90% of patients with a low incidence of mild adverse events.

OBJECTIVE

To compare the CBD clearance rates achieved after ESWL performed with 2 different lithotripters (Siemens Lithostar Plus and Storz Modulith SLX-F2) in a large cohort of patients with difficult CBD stones.

DESIGN

A retrospective analysis of a prospectively collected database.

SETTING

Tertiary care center.

PATIENTS

All of the consecutive patients who underwent ESWL because of difficult CBD stones between 1990 and 2012 were considered suitable for inclusion.

INTERVENTIONS

ESWL with Lithostar Plus or with Modulith SLX-F2.

MAIN OUTCOME MEASUREMENTS

CBD clearance.

RESULTS

Three hundred ninety-two patients with difficult CBD stones were treated; 199 patients were treated with the Lithostar Plus and 193 patients with the Modulith SLX-F2. CBD clearance was achieved in 349 patients (89.0%) with no significant difference between the patients treated with Lithostar Plus and those treated with Modulith SLX-F2 (90.5% vs 87.6%; P = .45). Patients treated with Modulith SLX-F2 underwent a significantly lower number of ESWL sessions (3 [range, 2 to 4] vs 3 [range, 2 to 4]; P = .0015), had a lower incidence of ESWL-related adverse events (5.2% vs 13.6%; P = .009), and never required opioid analgesia (P < .001).

LIMITATIONS

Retrospective design.

CONCLUSIONS

The Modulith SLX-F2 allows the same clearance rate as the Lithostar Plus but has a significantly lower incidence of adverse events and requires fewer ESWL sessions.

Diagnosis and management of choledocholithiasis in the golden age of imaging, endoscopy and laparoscopy

Biliary lithiasis is an endemic condition in both Western and Eastern countries, in some studies affecting 20% of the general population. In up to 20% of cases, gallbladder stones are associated with common bile duct stones (CBDS), which are asymptomatic in up to one half of cases. Despite the wide variety of examinations and techniques available nowadays, two main open issues remain without a clear answer: how to cost-effectively diagnose CBDS and, when they are finally found, how to deal with them. CBDS diagnosis and management has radically changed over the last 30 years, following the dramatic diffusion of imaging, including endoscopic ultrasound (EUS) and magnetic resonance cholangiography (MRC), endoscopy and laparoscopy. Since accuracy, invasiveness, potential therapeutic use and cost-effectiveness of imaging techniques used to identify CBDS increase together in a parallel way, the concept of “risk of carrying CBDS” has become pivotal to identifying the most appropriate management of a specific patient in order to avoid the risk of “under-studying” by poor diagnostic work up or “over-studying” by excessively invasive examinations. The risk of carrying CBDS is deduced by symptoms, liver/pancreas serology and ultrasound. “Low risk” patients do not require further examination before laparoscopic cholecystectomy. Two main “philosophical approaches” face each other for patients with an “intermediate to high risk” of carrying CBDS: on one hand, the “laparoscopy-first” approach, which mainly relies on intraoperative cholangiography for diagnosis and laparoscopic common bile duct exploration for treatment, and, on the other hand, the “endoscopy-first” attitude, variously referring to MRC, EUS and/or endoscopic retrograde cholangiography for diagnosis and endoscopic sphincterotomy for management. Concerning CBDS diagnosis, intraoperative cholangiography, EUS and MRC are reported to have similar results. Regarding management, the recent literature seems to show better short and long term outcome of surgery in terms of retained stones and need for further procedures. Nevertheless, open surgery is invasive, whereas the laparoscopic common bile duct clearance is time consuming, technically demanding and involves dedicated instruments. Thus, although no consensus has been achieved and CBDS management seems more conditioned by the availability of instrumentation, personnel and skills than cost-effectiveness, endoscopic treatment is largely preferred worldwide.

Efficacy of spyglass-guided electrohydraulic lithotripsy in difficult bile duct stones

BACKGROUND/AIMS

We aimed to evaluate the efficacy and safety of Spyglass-guided electrohydraulic lithotripsy (EHL) for difficult common bile duct stones (CBD) not amenable to conventional endoscopic therapy.

DESIGN

A retrospective study evaluating the efficacy of Spyglass-guided EHL in treating difficult CBD stones, in a single tertiary care center.

PATIENTS AND METHODS

All patients who underwent Spyglass-guided EHL from 2012 to 2013 were compared with a historical cohort who had ECSWL.

RESULTS

A total number of 13 patients underwent Spyglass-guided EHL, 8 (61.5%) of them were males. The mean age was 46.5 ± 5.6 years. Bile duct clearance was achieved in 13 (100%) of them. Seventy-six percent required only one Endoscopic Retrograde Cholangiopancreatography (ERCP) to clear the CBD, 7.7% required two ERCPs, and 15.4% required three ERCPs. Adverse effects (cholangitis) occurred in one patient (10%), whereas only 30 patients (64.4%) of the ESWL group had complete CBD stone clearance. Thirty-seven percent required one ERCP to clear the CBD, 35.6% required two ERCPs, and 20% required three ERCPs. Adverse effects happened in seven (15.5%) patients, where five (11%) had cholangitis and two (4.4%) had pancreatitis.

CONCLUSION

Although a retrospective design with a small sample size, we concluded that Spyglass-guided EHL is an effective procedure in treating difficult CBD stones.

Low-intensity shock wave therapy and its application to erectile dysfunction

Although phosphodiesterase type 5 inhibitors (PDE5Is) are a revolution in the treatment of erectile dysfunction (ED) and have been marketed since 1998, they cannot restore pathological changes in the penis. Low-energy shock wave therapy (LESWT) has been developed for treating ED, and clinical studies have shown that LESWT has the potential to affect PDE5I non-responders with ED with few adverse effects. Animal studies have shown that LESWT significantly improves penile hemodynamics and restores pathological changes in the penis of diabetic ED animal models. Although the mechanisms remain to be investigated, recent studies have reported that LESWT could partially restore corpus cavernosum fibromuscular pathological changes, endothelial dysfunction, and peripheral neuropathy. LESWT could be a novel modality for treating ED, and particularly PDE5I non-responders with organic ED, in the near future. However, further extensive evidence-based basic and clinical studies are needed. This review intends to summarize the scientific background underlying the effect of LESWT on ED.

Endoscopic management of bile duct stones: residual bile duct stones after surgery, cholangitis, and "difficult stones"

Endoscopic treatment has become, according to the latest recommendations, the standard treatment for common bile duct stones (CBDS), although in certain situations, surgical clearance of the common duct at the time of laparoscopic cholecystectomy is still considered a possible alternative. The purpose of this article is not to compare endoscopic with surgical treatment of CBDS, but to describe the various techniques of endoscopic treatment, detailing their preferential indications and the various treatment options that must sometimes be considered when faced with "difficult calculi" of the CBD. The different techniques of lithotripsy and the role of biliary drainage with plastic or metallic stents will be detailed as well as papillary balloon dilatation and particularly the technique of sphincterotomy with macrodilatation of the sphincter of Oddi (SMSO), a recently described approach that has changed the strategy for endoscopic management of CBDS. Finally, the overall strategy for endoscopic management of CBDS, with description of different techniques, will be exposed.

Endoscopic management of difficult common bile duct stones

Endoscopy is widely accepted as the first treatment option in the management of bile duct stones. In this review we focus on the alternative endoscopic modalities for the management of difficult common bile duct stones. Most biliary stones can be removed with an extraction balloon, extraction basket or mechanical lithotripsy after endoscopic sphincterotomy. Endoscopic papillary balloon dilation with or without endoscopic sphincterotomy or mechanical lithotripsy has been shown to be effective for management of difficult to remove bile duct stones in selected patients. Ductal clearance can be safely achieved with peroral cholangioscopy guided laser or electrohydraulic lithotripsy in most cases where other endoscopic treatment modalities have failed. Biliary stenting may be an alternative treatment option for frail and elderly patients or those with serious co morbidities.

Extracorporeal shock wave lithotripsy for pancreatic and large common bile duct stones

Extraction of large pancreatic and common bile duct (CBD) calculi has always challenged the therapeutic endoscopist. Extracorporeal shockwave lithotripsy (ESWL) is an excellent tool for patients with large pancreatic and CBD calculi that are not amenable to routine endotherapy. Pancreatic calculi in the head and body are targeted by ESWL, with an aim to fragment them to < 3 mm diameter so that they can be extracted by subsequent endoscopic retrograde cholangiopancreatography (ERCP). In our experience, complete clearance of the pancreatic duct was achieved in 76% and partial clearance in 17% of 1006 patients. Short-term pain relief with reduction in the number of analgesics ingested was seen in 84% of these patients. For large CBD calculi, a nasobiliary tube is placed to help target the calculi, as well as bathe the calculi in saline - a simple maneuver which helps to facilitate fragmentation. The aim is to fragment calculi to < 5 mm size and clear the same during ERCP. Complete clearance of the CBD was achieved in 84.4% of and partial clearance in 12.3% of 283 patients. More than 90% of the patients with pancreatic and biliary calculi needed three or fewer sessions of ESWL with 5000 shocks being delivered at each session. The use of epidural anesthesia helped in reducing patient movement. This, together with the better focus achieved with newer third-generation lithotripters, prevents collateral tissue damage and minimizes the complications. Complications in our experience with nearly 1300 patients were minimal, and no extension of hospital stay was required. Similar rates of clearance of pancreatic and biliary calculi with minimal adverse effects have been reported from the centers where ESWL is performed regularly. In view of its high efficiency, non-invasive nature and low complication rates, ESWL can be offered as the first-line therapy for selected patients with large pancreatic and CBD calculi.

Per-oral cholangioscopy

Direct endoscopic views of bile duct have been described in literature since the 1970s. Since then rapid strides have been made with the advent of technologically advanced systems with better image quality and maneuverability. The single operator semi-disposable per-oral cholangioscope and other novel methods such as the cholangioscopy access balloon are likely to revolutionize this field. Even though cholangioscopy is currently used primarily for characterization of indeterminate strictures and management of large bile duct stones, the diagnostic and therapeutic indications are likely to expand in future. The following is an overview of the currently available per-oral cholangioscopy equipments, indications for use and future directions.

Endoscopic retrograde cholangiopancreatography for non-gastroenterologists: what you need to know

Endoscopic retrograde cholangiopancreatography (ERCP) represents the most powerful and widely employed platform for pancreaticobiliary interventions. Endoscopic retrograde cholangiopancreatography allows diagnosis and treatment of a broad spectrum of diseases of the pancreaticobiliary tree that are both benign and malignant in nature. Endoscopic retrograde cholangiopancreatography continues to evolve rapidly, and non-gastroenterologists need to understand the indications, contraindications, limitations, and role of ERCP to effectively manage and coordinate the care of patients with known or suspected pancreaticobiliary disease. This article will review the role of ERCP in detail to further an understanding of the procedure as a whole and to assess when referral of a patient for an ERCP or other related test is indicated.

Extracorporeal shock wave lithotripsy and endotherapy for pancreatic calculi-a large single center experience

AIM

Large pancreatic ductal calculi and pain are a feature of chronic calcific pancreatitis (CCP) in the tropics. This large single center study evaluates the role of extracorporeal shock wave lithotripsy (ESWL) in fragmentation of large pancreatic stones and relief of pain in patients with CCP.

METHODS

Patients with CCP presenting with pain and large pancreatic duct (PD) calculi (>5 mm diameter) not amenable to extraction at routine endoscopic retrograde cholangio pancreatography (ERCP) were taken up for ESWL using a 3rd generation lithotripter. Stones in the head and body of pancreas were targeted at ESWL; 5,000 shocks were given per session. The calculi were fragmented to <3 mm size and then cleared by endotherapy. Pancreatic duct stents were deployed when indicated. A total of 1,006 patients underwent ESWL. Complete clearance was achieved in 762 (76%), partial clearance in 173 (17%) and unsuccessful in the rest. More than 962 (90%) of patients needed less than three sessions of ESWL. At 6 months, 711 (84%) of 846 patients who returned for follow up had significant relief of pain with a decrease in analgesic use. Complications were mild and minimal.

CONCLUSION

ESWL is an effective and safe modality for fragmentation of large PD calculi in patients with CCP.

Endoscopic management of biliary ductal stones

Bile duct stone management has greatly changed in the past 2 decades. Open surgical techniques have mostly been replaced by transoral endoscopic techniques. Routine common bile duct stones can be managed by standard biliary endoscopic sphincterotomy and extraction. Various advanced transoral techniques can also manage most difficult ductal stones. In skilled centers, laparoscopic ductal stone management has assumed a back-up role.

Epidural anesthesia is effective for extracorporeal shock wave lithotripsy of pancreatic and biliary calculi

AIM: To evaluate the efficacy of thoracic epidural analgesia for extracorporeal shock wave lithotripsy (ESWL).

METHODS: ESWL is an effective, non-invasive technique for the treatment of difficult pancreatic and large bile duct calculi. The procedure is often painful and requires large doses of analgesics. Many different anesthetic techniques have been used. Patients with either large bile duct calculi or pancreatic duct calculi which could not be extracted by routine endoscopic methods were selected. Thoracic epidural anesthesia (TEA) was routinely used in all the subjects unless contraindicated. Bupivacaine 0.25% with or without clonidine was used to block the segments D6 to D12. The dose was calculated depending on the age, height and weight of the patient. It was usually 1-2 mL per segment blocked.

RESULTS: Ninety eight percent of the 1509 patients underwent ESWL under TEA. The subjects selected were within American Society of Anesthesiologists grade I to III. ESWL using EA permitted successful elimination of bile duct or pancreatic calculi with minimal morbidity. The procedure time was shorter in patients with TEA than in those who underwent ESWL under total intravenous anesthesia.

CONCLUSION: Almost all patients undergoing ESWL with EA had effective blocks with a single catheter insertion and local anesthetic injection.