The present position concerning gallstone dissolution

A history of the dissolution of retained choledocholithiasis

BACKGROUND

Common duct calculi retained after gallbladder surgery continue to present a clinical challenge especially in the era of minimally invasive surgery. This review examines the strategy of dissolution therapy used throughout the history of biliary tract surgery and its use to the modern surgeon.

DATA SOURCES

Original journal articles and reviews were identified using standard surgical textbooks and MEDLINE. Keywords for searching included choledocholithiasis, dissolution, mono-octanoin, common duct stones, MTBE, cholic acid, and gallstones.

CONCLUSIONS

Dissolution therapy used initially as an alternative to open surgery is now used more effectively as an adjunct to laparoscopic or endoscopic biliary tract surgery. The current review demonstrates a majority of patients with retained choledocholithiasis respond to dissolution and can be safely managed without choledochotomy.

Gall-stone dissolution and recurrence: are we being misled?

Oral cholecystography repeated at six-months intervals is the standard method for determining reduction in size of gall stones (partial success) and complete dissolution of stones (complete success). In a comparative study of oral cholecystography and cholecystosonography six out of 14 patients with gall stones achieving complete success by oral cholecystographic criteria had stones still detectable by ultrasonography. Repeat oral cholecystography in a further 11 patients receiving post-dissolution maintenance treatment detected stones in two, whereas ultrasonography detected stones in seven. In future complete dissolution of gall stones should be reported only if both oral cholecystography and ultrasonographic studies give negative results and the progress of patients receiving post-dissolution maintenance treatment is monitored by ultrasonography rather than serial oral cholecystography.

The treatment of retained gallstones

Various techniques are available to evaluate patients suspected of having common duct stones before an operation on the biliary tract. In patients without jaundice, intravenous cholangiography with tomography may provide satisfactory visualization of the biliary system and its contents. Sonography and computerized axial tomography are useful noninvasive methods. Endoscopic retrograde and transhepatic cholangiography are invasive techniques; but, when successful, they provide the most precise preoperative information obtainable about the presence or absence of stones in the biliary system. The most appropriate diagnostic procedures must be carefully selected for each patient. Each year in 3,000 to 4,000 cases, stones are found remaining in the bile ducts after common duct exploration for the removal of stones. Retained stones can be treated by nonoperative extraction, by irrigation techniques and by surgical removal. Extraction methods probably deserve first consideration, if experienced personnel are available. The technique of irrigation of the common bile duct with cholic acid or other solutions, although limited in success, may also be tried; if these procedures fail, then reoperation is indicated.

Effect of ioglycamide (Biligram) on bile flow and biliary lipid secretion in man

Twenty-one anicteric patients with a t-tube in situ were studied between the ninth and 11th postoperative days. Eleven patients were given an intravenous infusion of the biliary contrast agent ioglycamide (Biligram), while the other 10 acted as controls. Bile flow was recorded and the biliary concentrations of ioglycamide, bile salt, phospholipid, and cholesterol estimated in the two groups. The biliary excretion of ioglycamide was associated with a significant choleresis which was probably due to the obligatory coupling of the osmotically active contrast agent molecules with water. Biliary ioglycamide excretion did not significantly alter bile salt secretion rates. In contrast, the biliary secretion of both phospholipid and cholesterol was significantly lowered (P less than 0.001). Unlike chenodeoxycholic acid, ioglycamide significantly reduced bile acid independent cholesterol secretion (P less than 0.01), although secretion rate in terms of mumol of bile acid was essentially unchanged.

Gastric mucosal damage by taurine and glycine conjugates of chenodeoxycholic acid

Bile damage to gastric mucosa may be demonstrated by means of changes in the transmucosal movement of H+ and Na+ ions. In the present study pure 10 mM solutions of taurine and glycine conjugates of chenodeoxycholic acid were instilled into canine Heidenhain pouches. Solutions were prepared at pH 2, 4, and 8, as previous work had shown a greater damaging effect at low pH. The present study confirmed this pH effect, but only with respect to movement of Na+ ion for taurine conjugates. The magnitude of the changes in ionic movements was much greater with pure bile acid solutions than that seen previously with whole bile. These findings are discussed. The greater damage seen below the pKa of the bile acid conjugates suggests that its nonionized form is the more damaging.

Bile salt metabolism. II. Bile salts and disease

Alterations of bile salt metabolism have been shown in numerous diseases. Liver damage results in elevated serum bile salt concentrations which may be useful as a sensitive index of hepatocellular disease. Changes in the relative proportions of the individual bile salts in serum occur with cholestasis. Urinary excretion of bile salts, largely in the form of sulphates, increases as a compensatory mechanism. Ileal disease or resection causes bile salt melabsorption. The increase in colonic bile salts produces a watery diarrhoea while the decrease in duodenal levels may cause steatorrhoea. Cholelithiasis may result from alteration in the relative proportions of cholesterol, lecithin and bile salts in bile. The mechanism apparently differs in various conditions predisposing to gallstone formation. A primary alteration of bile salt metabolism has been postulated in several other conditions. Considerable interest centres on the importance of metabolites of bile salts in the pathogenesis of colonic carcinoma. Chenodeoxycholic acid is a successful though costly treatment for selected patients with cholesterol gallstones. Bile salt binding agents, such as cholestyramine, are extremely useful especially in the control of pruritus in patients with cholestasis.

Dissolution of retained bile duct stones using heparin

Five cases of retained bile duct stones treated with heparin in normal saline are reported. In 2 cases the stones were retained in the left hepatic duct, proximal to the T tube. Infusion of heparin in normal saline was found to be simple and effective in treating retained bile duct stones without obvious side-effects. If stones are inadvertently left in the common bile duct following surgery, attempts should be made to encourage them to pass by heparin infusion through the T tube before a second operation is contemplated. Sufficient time must be allowed before the treatment is considered to have failed.

Treatment of retained bile duct calculi with T-tube infusion of sodium cholate and heparin

A series of 26 patients with retained radiolucent bile duct calculi diagnosed at postoperative cholangiagrophy through the T-tube is presented. All patients were treated with infusion of 15-20 g sodium cholate in 1000 ml saline and 20,000 units of heparin in 1000 ml saline per 24 hours. In 19 of 26 patients (73 per cent) the calculi disappeared. No complications were encountered. This treatment is recommended prior to reoperation in all patients with retained radiolucent bile duct calculi diagnosed by postoperative cholangiography through the T-tube.

Chenodeoxycholic acid induced liver injury in pregnant and neonatal baboons

The prolonged feeding of chenodeoxycholic acid produces hepatic injury in both pregnant and non-pregnant baboons. CDC feeding does not adversely affect ovarina function and no teratogenic effects of this bile acid were noted in 16 live birth and two stillborn progeny of CDC fed animals. However, 10 of the 16 live birth neonates and one stillborn had focal hepatic lesions histologically similar to those observed in the adult animals. In addition one neonate had gross hepatic necrosis. The severity of the liver damage was related to the content of lithocholic acid in the bile of both the neonates and their mothers. Experiments with 14C-chenodeoxycholic and 14C-lithocholic acid demonstrate that the lithocholate in the enterohepatic circulation of the neonate is derived from the CDC fed to the pregnant adult. In the gallbladder bile of the neonate most, but not all, of the lithocholate is conjugated but unsulfated. Both newborn and adult baboons sulfate lithocholic acid but to an extent less than that reported for man. Less efficient sulfation of lithocholic acid in the baboon may exaggerate the toxicity of CDC feeding in this species compared to man. Nevertheless, the potential for adverse effects on the fetal liver must be recognized as a risk associated with the use of chenodeoxycholic acid in women of child-bearing age.

Influence of bile acids upon biliary cholesterol and phospholipid secretion in the dog

The relationship between taurocholate or taurochenodeoxycholate secretion and cholesterol and phospholipid secretion in bile was studied in anaesthetized dogs infused with graded doses of these bile acids. Cholesterol output was linearly related to bile acid output during both taurocholate and taurochenodeoxycholate infusions. On the average 1.45 nmol and 4.70 nmol of cholesterol were secreted per mumol of taurocholate or taurochenodeoxycholate respectively (P less than 0.001). A linear relationship was also observed between phospholipid secretion rate and taurocholate or taurochenodeoxycholate secretion rates. However, the amounts of phospholipid secreted per mumol of taurocholate or taurochenodeoxycholate (respectively 0.10 and 0.15 mumol) were not significantly different. Thus, bile was less saturated with cholesterol during taurocholate infusions than during taurochenodeoxycholate infusions. These results are consistent with the hypothesis that micelle formation by bile acids is a major determinant of cholesterol and phospholipid secretion in the dog.