The role of extracorporeal lithotripsy (ESWL) in the treatment of gallstones

Gallbladder stones: shockwave therapy

Within the past 7 years, gallbladder lithotripsy by shockwaves has been proven to be a safe and effective non-invasive therapy for selected patients with gallstone disease. While regulatory decisions prevent shockwave therapy from being used more frequently in the USA, the number of patients treated in Europe and Asia is increasing constantly. At our institution, a relatively constant number of about 250 new patients per year have been treated since 1988 (Figure 4). About 20% of patients with gallstones are suitable for shockwave therapy according to present criteria. The rate of evacuation of all fragments is determined by the initial stone number and stone size, the success at stone fragmentation, adjuvant bile acid dissolution therapy, and gallbladder contractility. In contrast to laparoscopic cholecystectomy (Dubois et al, 1989; Perissat et al, 1989; Southern Surgeons Club, 1991), shockwave therapy does not require general anaesthesia. And in contrast to direct contact dissolution therapy of gallbladder stones using MTBE (Thistle et al, 1989), lithotripsy is non-invasive. In the majority of patients, complete fragment disappearance takes several months. Preliminary analyses of the cost-effectiveness of lithotripsy have revealed that lithotripsy, including retreatments and bile acid medication for recurrent stones, costs about as much as open cholecystectomy (Rothschild et al, 1990; Bass et al, 1991). The ideal patient for gallbladder lithotripsy has a single radiolucent stone < or = 20-25 mm in diameter in a functioning gallbladder (Figure 1). In patients with such stones, nearly all studies have confirmed a favourable outcome with rapid clearance of all fragments and a relatively low rate of stone recurrence. For carefully selected patients, extracorporeal shockwave lithotripsy is therefore an attractive non-invasive therapy.

Non-surgical management of bile duct stones refractory to routine endoscopic measures

Endoscopic sphincterotomy and percutaneous approaches to the biliary tract have revolutionized the treatment of bile duct stones. Both the endoscopic and transhepatic approaches are less invasive than open surgery. This is an advantage for the mostly elderly and frail patients with common bile duct stones. Other patients with intrahepatic stones, e.g. young patients with oriental lithiasis, may also profit from the non-surgical approach. In this latter group it is often difficult for the surgeon to obtain access to the stone-bearing bile ducts. Due to the anatomical situation, size or impaction of stones the non-surgical approach, including mechanical disintegration, may primarily fail. Several techniques such as intracorporeal lithotripsy using electrohydraulic probes or laser light, extracorporeal shockwave lithotripsy or direct contact dissolution are now available and often allow complete clearance of the bile ducts. If a kidney lithotripter with radiographic devices is available, it should be used after an attempt at mechanical lithotripsy has failed (Figure 1). According to the literature, experience with this method is greater than with any other 'third-step approach'. The procedure is simple, relatively safe and successful in approximately 80% of patients. However, in at least one third of patients, several sessions have to be performed and further endoscopy is frequently required for extraction of fragments. Intracorporeal techniques may become the procedure of choice in the future, at least in patients with common bile duct stones. At the moment, however, the different devices are still not fully developed and too susceptible to damage. A further major drawback, especially with high-energy electrohydraulic intracorporeal lithotripsy, is the danger of bile duct injury or even perforation, so that most procedures must be performed under optical control. The use of contact dissolution cannot generally be recommended. Treatment with mono-octanoin or modified mono-octanoin solvents takes too long, is often not successful and has a high rate of side-effects. MTBE may shorten the procedure considerably, but is suitable only for cholesterol stones, and the danger of spill-over into the intestine with absorption and systemic side-effects has to be weighed against the probability of success.

Extracorporeal shock-wave lithotripsy and endoscopy: combined therapy for problematic bile duct stones

Endoscopic treatment of bile duct stones is currently successful in 86% of patients. We prospectively studied the efficacy and complication rate of extracorporeal shock-wave lithotripsy (ESWL) of problematic bile duct stones combined with endoscopy. When stone removal was not possible, patients were subjected to ESWL. Fragmented stones were removed endoscopically. During 1 year, 220 patients presenting with choledocholithiasis were diagnosed and 188 were successfully treated endoscopically. In all, 3 subjects received alternative treatment and the remaining 29 (13%) constituted our study group; 19 (65%) were women and the mean age was 76.7 years. Overall, 22 (76%) were high-risk patients; 23 (79%) were jaundiced and 9 (31%) had cholangitis at admission. The most frequent indication for ESWL was stone size. Stone fragmentation was achieved in 80% of cases. Complications were mild and were managed conservatively. No patient died. Complete stone clearance was possible in 23 (80%) cases. The association of ESWL and endoscopy enhanced the success rate of endoscopic stone clearance from 86% to 96%. During the same period, open surgery was performed in 4 cases for residual common bile duct (CBD) stones and in 32 cases in association with simultaneous cholecystectomy.

Gallstone lithotripsy by extracorporeal shock waves

Extracorporeal shock-wave lithotripsy (ESWL) in combination with adjuvant litholytic therapy using chenodeoxycholic acid and ursodeoxycholic acid (7 to 8 mg/kg body weight/day of each acid) is a safe and effective, novel nonsurgical approach to gallbladder stones, provided the patients are carefully selected. Experience has shown that patients with a radiolucent solitary stone in a functioning gallbladder are the best candidates. In addition, ESWL is a worthwhile noninvasive alternative to open surgery in patients with bile duct stones in whom routine endoscopic measures have failed.