ERCP and Related Technologies: A Clinical Update

David L. Carr-Locke, MD, FRCP, FACG, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.

Disclosures

May 22, 2000

In This Article

Choledocholithiasis

This session comprised 3 lectures, on the following topics: gallstone pancreatitis, long-term stenting for choledocholithiasis, and techniques for bile duct stone removal.

Dr. Carr-Locke concentrated his discussion on the 4 randomized controlled trials of ERCP and endoscopic sphincterotomy (ES) in acute biliary pancreatitis (ABP).[52,53,54,55] He indicated that a number of observational reports had preceded the first trial, beginning in 1983, which suggested that ERCP and ES in acute gallstone pancreatitis were potentially beneficial. The first of these trials -- his own UK trial published in 1988[52] -- randomized 121 patients with suspected ABP to receive conventional supportive care or an urgent ERCP within 72 hours of admission. Choledocholithiasis was found in 25% of mild and in 63% of severe attacks using the Glasgow stratification system. In all cases, gallstones were successfully removed. The 4 important overall findings were that ERCP could be safely performed, that there was a significantly reduced morbidity (from 61% to 24%), that there was a reduction in mortality (18% to 4%) in severe attacks, and that this approach reduced the hospital stay in severe pancreatitis.

A second controlled trial from Hong Kong, published in 1993,[53] randomized 195 patients with acute pancreatitis (of whom approximately two thirds eventually were shown to have ABP) to treatment. One group received supportive care and the other early ERCP within 24 hours of admission. Similar to the UK study, reductions in morbidity and mortality were shown for severe cases, but not for mild cases, with the additional finding that there was a significant, concomitant incidence of cholangitis, which benefited from endoscopic intervention.

The third randomized study, conducted by a multicenter German group and published in 1997,[54] set forth a different hypothesis: that endoscopic intervention in patients without convincing biliary obstruction in ABP would not benefit. They randomized 238 patients to supportive care or ERCP within 72 hours and excluded patients with a significantly elevated bilirubin in order to exclude concomitant biliary obstruction. They found no significant differences in outcomes between the 2 randomized groups, except that patients who received early ERCP had a higher incidence of respiratory failure and more severe complications. This finding did not seem to relate to the severity of the pancreatitis. Thus, although the hypothesis was validated, many concerns have been expressed about this study, particularly the low enrollment of patients in many of the centers.

The fourth study, from Poland,[55] has not yet appeared as a full manuscript but has been presented at many international meetings. Two hundred and eighty patients with ABP underwent emergency endoscopy within 24 hours of disease onset; stones were removed if found at the papilla. Patients (N = 205) were subsequently randomized to supportive care or emergency ES, irrespective of findings, and significant reductions in morbidity (36% to 17%) and mortality (13% to 2%) were demonstrated, which were more marked with earlier intervention.

With 4 trials of different designs, from different parts of the world, it has been difficult to reach a consensus regarding the role of ERCP and ES in ABP. If one accepts that the 2 best-designed studies -- ie, the studies from the UK and Hong Kong -- come to the same conclusion that ERCP and ES are beneficial in more severe forms of ABP, then this should be the management strategy for all patients with ABP. A recent meta-analysis supports these conclusions.[56]

Dr. Huibregtse, considered by many as one of the masters of ERCP, discussed the development of endoscopic sphincterotomy and stone extraction techniques in the 1970s as endoscopes and accessory equipment improved. In the late 1970s, various types of nasobiliary drain were introduced, followed by the development of the biliary endoprosthesis, or stent, in 1979.[57] With improvements in stone fragmentation and extraction techniques in the last 20 years, the use of nasobiliary drains or stents is more likely to be a temporary intervention to protect the patient from stone obstruction between different endoscopic sessions. The earlier suggestion that stents could be used for long-term treatment of difficult bile duct stones has become less popular. Dr. Huibregtse chose to review several studies published since 1994 to provide a modern basis for the use of drains and stents in stone disease. Two studies[58,59] emphasize the effectiveness of short-term use of stents during the period when repeat attempts at endoscopic bile duct clearance are being made. Two other studies[60,61] reported high complication rates of 40% to 50% in patients treated long term with stents for retained stones; a number of deaths resulted from biliary infection.

These studies concluded that stents should no longer be used as permanent therapy, apart from exceptional circumstances. A comparison of 2 management studies was reported[62] that showed insignificant differences in early complication rates between limited sphincterotomy with stent placement on the one hand and standard sphincterotomy with stone extraction and lithotripsy on the other. Long-term complications, however, were much higher in the stent group, which, again, favors this mode of therapy as a temporary one only. Finally, a Hong Kong study[63] confirmed that stone size can be reduced by the mechanical effect of stents placed after initial failed endoscopic therapy, but that overall they should still be regarded as a temporary measure.

Dr. Huibregtse concluded that one should not forget that surgical techniques and perioperative care have also improved considerably over the last 2 decades concomitant with developments in endoscopic therapy, and that patients should not be denied a safe surgical stone removal when endoscopic attempts fail.

Dr. Haber,[64] from Wellesley Hospital in Toronto, provided a comprehensive review of current strategies for endoscopic management of bile duct stones, beginning with indications that applied to all postcholecystectomy patients, and including emergency situations such as cholangitis and gallstone pancreatitis, precholecystectomy settings as determined by the availability of laparoscopic techniques for stone removal, settings in which patients are unlikely to undergo cholecystectomy in the future because of comorbidity or choice, and other postoperative situations where further surgery would be undesirable. Patients were selected for endoscopic therapy on the basis of a number of criteria, including a high likelihood of finding a bile duct stone, clinical history, laboratory values, and results of imaging studies. But unquestionably it is the level of endoscopic skill available that is a significant determinant of the use of these techniques. Dr. Haber also discussed the few contraindications to endoscopic therapy of bile duct stones, many of which are relative. Severe comorbidity, particularly that limiting use of sedation or anesthesia, is a contraindication, as are anatomical factors (eg, surgically altered anatomy, which makes access difficult or impossible in some cases). Other endoscopes, such as pediatric colonoscope and enteroscope, may have to be used in certain situations as an alternative to endoscopic therapy. Significant coagulopathy was shown to be a contraindication to sphincterotomy, but bile duct drainage appears to be a satisfactory temporizing measure.

Dr. Haber also discussed the various types of therapeutic duodenoscopes available: specialized duodenoscopes for pediatric use, prototype instruments such as the 2-channel duodenoscope, and the "mother-baby" dual endoscopes required for some forms of intracorporeal lithotripsy. He also cited the wide array of sphincterotomes: baskets, balloons for standard techniques, and some combined hybrid devices such as the balloon sphincterotome (which he considered clumsy and expensive). He then launched into a discussion of various forms of lithotripsy.

Mechanical lithotripsy is the most commonly performed fragmentation technique, usually performed through the endoscope, but Dr. Haber advised that outside-the-scope techniques also be learned to avoid the complication of basket impaction. Such systems can be used as rescue devices after removal of the impacted basket handle, withdrawal of the endoscope, and insertion of the flexible metallic sheath, after which the cranking handle of various designs can be attached and lithotripsy or basket removal can be achieved. A number of through-the-scope mechanical lithotripsy systems are available, the Olympus device being the most popular. This device is available in 2 sizes for different endoscope channel diameters, and the baskets are now available as preassembled disposable items. A completely disposable system is also available and is gaining in popularity, but the system of a standard basket convertible to a lithotriptor is mostly used outside the United States.

Intracorporeal shockwave lithotriptors deliver their energy either through probes to achieve electrohydraulic lithotripsy (EHL) or through laser fibers. EHL has the merit of being less costly than laser lithotripsy, but it requires a dual endoscope arrangement to target the stones precisely and avoid bile duct injury. Laser lithotripsy systems are expensive and require dual endoscope systems to allow direct targeting, but they are often available in urology departments and are portable. Lasers allow the distinction of tissue and stone, obviating the need for direct visualization, and fluoroscopic targeting therefore becomes possible. Smart, newer laser systems have also become less expensive, but these are not yet available in the United States.

Extracorporeal shockwave lithotripsy (ESWL) systems are primarily available for renal stone fragmentation, but can be applied to fragmentation of bile duct stones and principally use fluoroscopic targeting rather than ultrasound. ESWL has not been particularly popular in the United States.

Dr. Haber also discussed the usual technical sequence when standard approaches fail. He emphasized many of the technical points of standard stone removal, such as not displacing the stone too proximally before attempted removal, not opening a basket distal to a stone in order to avoid pushing it into an accessible position, assessing the distal bile duct through which the stone must be removed, ensuring sufficient diameter, and understanding the mechanical differences between balloon and basket extraction techniques. He also emphasized the difficulties in diagnosis, which may result from unusual anatomical deformities, additional diagnoses such as polypoidal tumors, and specific anatomic location where stones may be missed (such as the mouth of a cystic duct, intrahepatic duct, and even the distal bile duct). Dr. Haber further emphasized limitations of fluoroscopic resolution with regard to patient characteristics, quality of equipment, and density of contrast used. It is important not to obscure certain parts of the bile duct; changing endoscope position may be necessary to achieve a complete cholangiographic evaluation in some cases.

Dr. Haber subsequently described the usual next step in the sequence as being through-the-scope mechanical lithotripsy, with only very few stones unbreakable after basket entrapment. If these techniques fail, then intracorporeal lithotripsy may be favored by many as the next step, with EHL being used more widely than laser lithotripsy. For centers with easy access to ESWL -- particularly those outside the United States -- this would be a reasonable alternative, with the provision that biliary drainage has been achieved by nasobiliary tube or stent.

Finally, Dr. Haber discussed a retrospective series from his own institution of 400 consecutive patients with choledocholithiasis seen over a 2-year period, in whom 475 procedures were performed by 2 endoscopists. Cholangiography was achieved in 99.3% of patients, and sphincterotomy in 98.5%. Two procedures were needed in 54 patients, and 3 or more in 22, with 319 patients requiring only 1 procedure to clear the bile duct. Failures at this stage were usually due to abnormal anatomy. In those with successful sphincterotomy, standard techniques were used in 87.7% of cases, with additional techniques in 22.3%, including mechanical lithotripsy, EHL, laser lithotripsy, and stent or nasobiliary tube. Mechanical lithotripsy was successful in 94% of cases and only 10 patients required surgery, which gave an overall endoscopic success rate of 97.5%. He also quoted a study of 72 consecutive patients undergoing EHL for difficult stones, which showed successful fragmentation in 94% of cases, the majority (74%) of which were achieved after 1 session, 19% after 2 sessions, and 7% after 3 or more. Complications were minimal; there was no related mortality, and overall clearance was 94%.

Dr. Haber concluded that modern endoscopic techniques and a high degree of expertise can allow the vast majority of patients with choledocholithiasis to be treated, and that patients who fail standard methods should be considered for referral to such centers of expertise when appropriate.

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....