Biliary sludge: Sludge is a mixture of gallbladder mucin and small cholesterol or calcium bilirubinate crystals from which macroscopic stones can develop (GE 1988;95:508). Sludge can be detected by US and can cause biliary sx such as colic, cholecystitis, or pancreatitis. Pts with asymptomatic sludge can be managed expectantly. Pts who have rapid weight loss, take ceftriaxone, take octreotide, are pregnant, or have undergone organ transplantation are at risk for sludge (Ann IM 1999;130:301).

Consequences of stone development: Pts with gallstones may (1) remain asymptomatic; (2) develop biliary colic from intermittent, brief cystic duct obstruction; (3) develop acute cholecystitis from prolonged cystic duct obstruction, with secondary inflammation and bacterial infection; (4) develop chronic cholecystitis from recurrent acute bouts; (5) experience migration of stones into the common bile duct and into the duodenum that may cause pain, pancreatitis, or cholangitis; (6) develop gallbladder cancer; or (7) develop gallstone ileus (bowel obstruction by a gallstone).

Acalculous cholecystitis: This condition is cholecystitis in the absence of stones. It is most often seen in pts as a complication of major surgery, trauma, or burns. The precise mechanisms are unknown (J Am Coll Surg 1995;180:232).

Xanthogranulomatous cholecystitis: This abnormality is found in about 1.7% of excised gallbladders. It is a destructive, fibrosing, inflammatory condition of the gallbladder characterized by the presence of lipid-laden macrophages, which possibly develop in response to extravasated bile (J Clin Pathol 1987;40:412).

Biliary colic: Most gallstones do notcause sx. The most common sx associated with gallstones is referred to as biliary colic (Postgrad Med 1991;90:119). The hallmark of biliary colic is discrete, unpredictable attacks of pain, lasting minutes to 5 hr before subsiding. The frequency of attacks is greater at night. The pt feels well between attacks. The pain is generally epigastric or RUQ (and occasionally substernal or LUQ). The pain often radiates outside the abdomen, typically to below the scapula. Nausea and vomiting may occur. Fever is uncommon without cholecystitis. Contrary to common teaching, there is no evidence that fatty food intolerance, belching, or bloating are related to the development of gallstones (Scand J Gastroenterol 2000;35:70). For sx that occur predictably or very frequently (> once weekly), a cause other than gallstones should be considered.

Acute cholecystitis: In this complication, the pt begins with an attack of biliary colic that fails to resolve. The pain tends to localize to the RUQ and may be associated with vomiting. Fever may develop. An important minority of pts may have little if any pain, especially diabetics, the immunocompromised, pts with CNS disease, and pts on steroids.

Acute pancreatitis: Gallstones may first present with sx of AP (p 187).

Choledocholithiasis: These pts may present with sx of biliary colic (frequently with radiation to the scapula), jaundice, dark urine, or pancreatitis, or they may be asymptomatic.

Cholangitis: Classically these pts present with Charcot’s triad: fever, RUQ pain, and jaundice. All of these findings might notnecessarily be present.

Biliary colic: US is the test of choice for pts with suspected biliary colic. A typically quoted sensitivity is 97%, with specificity at 99%. However, since many pts with negative US never have the gold standard test (cholecystectomy), adjusted sensitivities of 90% for sensitivity and 97% for specificity have been proposed (Arch IM 1994;154:2573). CT is insensitive and nota reliable negative. In oral cholecystogram (OCG), pts swallow giant tablets of a contrast agent. The contrast agent is excreted in bile and taken up in the gallbladder. OCG is notoften used because it is less sensitive than US and because it is nonspecific if nonvisualization of the gallbladder is taken as a positive.

Acute cholecystitis: US is usually the test done first to look for gallstones in this setting. US may reveal direct evidence of cholecystitis, such as a thickened gallbladder wall or surrounding fluid collection. US may show evidence of dilated bile ducts from choledocholithiasis. If US is negative and acute cholecystitis is suspected, a radionuclide scan (typically called a HIDA scan no matter what isotope is used) is performed.

In normal pts, the radiolabel is excreted into bile and flows into the gallbladder. If the cystic duct is obstructed (as in acute cholecystitis), the tracer is notvisualized in the gallbladder and the test is positive. The sensitivity is 97% and the specificity is 90%. Since cholecystitis may occur without stones, HIDA scanning has advantages over US in the dx of acalculous cholecystitis.

Common duct stones: CT and US are poor tests for common duct stones. ERCP is the test of choice for pts with a high clinical suspicion of common duct stones (bilirubin >4 mg/dl, cholangitis, or dilated CBD on US with bilirubin 1.8-4 mg/dl) because of the potential for endoscopic rx. If the pt is undergoing surgery, then an intraoperative cholangiogram is a cost-effective alternative when suspicion is intermediate. Preoperative EUS or MRCP are alternatives when suspicion is intermediate (Gastro Endosc 2010;71:1).

Laparoscopic cholecystectomy (lap chole): Pts with symptomatic gallstones should undergo cholecystectomy unless there is a major medical contraindication. Asymptomatic pts are better off waiting for the development of sx than having prophylactic surgery. Those with acute cholecystitis should undergo surgery promptly after resuscitation because up to 20% will have gangrene or perforation, and a delayed operation results in higher complication rates (BMJ 2002;325:639). The laparoscopic approach has replaced open cholecystectomy without a randomized trial to support its use. Shortened hospital stays, reduced pain, shorter recovery time, and consumer demand have dictated that an RCT will never be done. Expected mortality of lap chole is 0.1-0.2%, and complications occur in 5%. These rates are similar to the rates for the open operation (Ann Surg 1993;218:129). Contraindications to the laparoscopic approach include scarring or inflammation that prevents access to the RUQ, diffuse peritonitis, and coagulopathy. The laparoscopic approach cannot be used for all pts, and some pts (less than 5%) must be converted to the open operation. Though indications for lap chole are supposedly no different than for open chole, the advent of the laparoscopic approach has increased utilization by about 11% (Surg Endosc 1996;10:746).

Lap chole and the common bile duct: Access to the bile duct is notas easy with lap chole as with open chole. About 8-17% of pts who undergo cholecystectomy are diagnosed with common bile duct stones (CBDS), and 1-2% will have retained stones diagnosed after surgery (J Am Coll Surg 1998;187:584). A great deal of effort has been put into methods of predicting the presence of common duct stones based on noninvasive data such as LFTs and US findings. About 90% of pts are considered low risk for CBDS because they have normal LFTs, no bile duct dilatation, and no hx of jaundice or pancreatitis. Even in this low-risk group, the incidence of stones is up to 5%. An algorithm for management of suspected common duct stones is available (Gastro Endosc 2010;71:1). When there is a high probability of stones (bilirubin >4 mg/dl, CBD stone on US, cholangitis, or dilated CBD on US with bilirubin 1.8-4 mg/dl) ERCP is performed prior to lap chole. When there is an intermediate probability of stones (abnormal LFTs, gallstone pancreatitis, dilated CBD on US, or age 55 and none of the high probability findings just discussed) then intraoperative cholangiogram, MRCP or EUS are considerations. Pts with positive cholangiograms undergo (1) postoperative ERCP with sphincterotomy and stone extraction, (2) laparoscopic removal of common duct stones (in the hands of experts) (World J Surg 1998;22:1125), or rarely (3) conversion to an open operation. Laparoscopic methods to explore the bile duct have fewer complications and cost less if done at expert centers, but those outcomes are notlikely in the typical community (Am Surg 1999;65:135). Local expertise usually dictates the approach.

Complications of cholecystectomy: The most feared complication of lap chole is bile duct injury. Bile duct injuries can be (1) major transections or ligations of the ducts, (2) leaks from the cystic duct stump, or (3) leaks from superficial branches of the right hepatic
ducts that are exposed at surgery (Am J Surg 1994;167:27). Biliary injuries occur more often in the hands of inexperienced surgeons (Brit J Surg 1995;82:307) and in acute cholecystitis (Arch Surg 1996;131:382). Pts with bile duct injuries present with pain and, to varying degrees, abdominal distention, ileus, and fever. LFTs may be normal or near normal in pts with leaks, but jaundice develops if the duct has been ligated. When a leak is suspected, HIDA scan usually demonstrates the leak and imaging studies may show a fluid collection. Leaks of the cystic duct stump or branches of the right hepatic system can be treated by placing a stent across the sphincter of Oddi at ERCP (Gastrointest Endosc 1993;39:416). As long as the stent crosses the sphincter and reduces pressure in the bile duct, the leak is sealed in the vast majority of cases (Am J Gastro 1995;90:2128). The stent is removed several weeks later, and closure of the leak is verified. Some experts prefer to do a sphincterotomy and place a nasobiliary tube. The nasobiliary tube usually can be removed in a few days when the edema of the sphincterotomy subsides, and the pt is spared a second procedure. No direct comparative studies are available. Major transections may require operative intervention and are associated with a high incidence of subsequent stricture, high cost, and mortality (Ann Surg 1997;225:268). Other notable complications are bleeding and bowel injury (Nejm 1991;324:1073). Stones may be lost into the abdomen and infrequently result in infectious or mechanical complications (Surg Endosc 1999;13:848).