Table 18.1 Nomenclature of bone tumors
• 75% of gallstones contain cholesterol and are usually associated with obesity, female sex, diabetes mellitus; mixed stones are most common (80%), pure cholesterol stones account for only 10% of stones.
• 25% of gallstones are pigment stones (bilirubin, calcium, and variable organic material) associated with hemolysis and cirrhosis. These tend to be black pigment stones that are refractory to medical therapy.
• 50% of mixed-type stones are radiopaque.
Fig. 5.29 Typical ultrasound image of cholecystolithiasis with round−oval stone (arrows) and echo shadow.
Sonography is the method of choice to confirm cholecystolithiasis (Fig. 5.29). Stones are a frequent finding at sonography of patients with atypical or no biliary symptoms.
Calcium-containing stones are detected by plain radiography (Fig. 5.30). Choledochus stones can be detected by ERCP (Fig. 5.31). It is assumed that 10% of patients with gallbladder stones also have choledochus stones. The symptoms vary. Typical is either an intermittent obstructive jaundice, mostly in connection with a pain attack, pancreatitis, or cholangitis. However, many patients have no or only minor symptoms. In contrast to cholecystolithiasis, biliary colic with choledocholithiasis is often associated with vomiting. About three-quarters of all patients with choledocholithiasis have pain, which is virtually indistinguishable from that of cholecystolithiasis with respect to localization, severity, and radiation.
Acute cholecystitis can be diagnosed by sonography, MRI and CT.
In general, gallstone colic is so typical that it is easily diagnosed. The following must be excluded in differential diagnosis: right-sided kidney colic, thromboses of mesenteric veins or arteries, acute inflammation of a dorsally and cranially placed appendix, duodenal ulcer, hepatitis, and pancreatitis, which is often caused by biliary obstruction. Epigastric and umbilical hernias are also rare causes of pain. Myocardial infarction and right-sided heart failure with acute congestion of the liver are two diseases of organs outside of the abdomen that may mimic gallstone colic.
An acute perihepatitis, which is mostly observed in young women, can easily be misinterpreted as cholelithiasis.
Fig. 5.30 Gallstones in plain radiograph.
Fig. 5.31 Distal choledocholithiasis (longitudinal oval contrast- sparing structure) and status after cholecystectomy (ERCP).
Generally normal unless patient has biliary obstruction (elevated alkaline phosphatase, bilirubin).
• Ultrasound of the gallbladder will detect small stones and biliary sludge (sensitivity, 95%; specificity, 90%); the presence of dilated gallbladder with thickened wall is suggestive of acute cholecystitis.
• Nuclear imaging (HIDA scan) can confirm acute cholecystitis (>90% accuracy) if gallbladder does not visualize within 4 hours of injection and the radioisotope is excreted in the common bile duct.
Life-style changes (avoidance of diets high in polyunsaturated fats, weight loss in obese patients-however, avoid rapid weight loss).
ACUTE GENERAL Rx
• The management of gallstones is affected by the clinical presentation.
• Asymptomatic patients do not require therapeutic intervention.
• Surgical intervention is generally the ideal approach for symptomatic patients. Laparoscopic cholecystectomy is generally preferred over open cholecystectomy because of the shorter recovery period.
• Laparoscopic cholecystectomy after endoscopic sphincterectomy is recommended for patients with common bile duct stones and residual gallbladder stones. Where possible, single-stage laparoscopic treatments with removal of duct stones and cholecystectomy during the same procedure is preferrable.
• Patients who are not appropriate candidates for surgery because of coexisting illness or patients who refuse surgery can be treated with oral bile salts: ursodiol (Actigall) 8 to 10 mg/kg/day in two to three divided doses for 16 to 20 months, or chenodiol (Chenix) 250 mg bid initially, increasing gradually to a dose of 60 mg/kg/day. Candidates for oral bile salts are patients with cholesterol stones (radiolucent, noncalcified stones), with a diameter of =15 mm and having three or fewer stones. Candidates for medical therapy must have a functioning gallbladder and must have absence of calcifications on CT scans.
• Direct solvent dissolution with methyl tert-butyl ether (MTBE) can be used in patients with multiple stones with diameter =3 cm; this method should be used only by physicians experienced with contact dissolution. Administration of the solvent is either through percutaneous transhepatic placement of a catheter into the gallbladder or endoscopic retrograde catheter placement with subsequent continuous infusion and aspiration of the solvent either manually or by automatic pump system. MTBE is a powerful cholesterol solvent and can dissolve stones in a few hours (>90% dissolution over a 2-hours infusion).
• Extracorporeal shock wave lithotripsy (ESWL) is another form ofmedical therapy. It can be used in patients with stone diameter of =3 cm and having three or fewer stones.
• Recurrence rate after bile acid treatment is approximately 50% in 5 years. Periodic ultrasound is necessary to assess the effectiveness of treatment.
• Gallstones recur after dissolution therapy with MTBE in >40% of patients within 5 years.
• Following extracorporeal shock wave lithotripsy, stones recur in approximately 20% of patients after 4 years.
• Patients with at least 1 gallstone <5 mm in diameter have a greater than fourfold increased risk of presenting with acute biliary pancreatitis. A policy of watchful waiting in such cases is generally unwarranted.
• A potential serious complication of gallstones is acute cholangitis. ERCP and endoscopic sphincterectomy (EC) followed by interval laparoscopic cholecystectomy is effective in acute cholangitis.