Hepatobiliary And Pancreatic Surgery (100q).1

In the past, choledochal cyst was treated by Roux-en-Y cystojejunostomy, but long-term results were poor. Excision of the cyst is essential to prevent recurrent pancreatitis. In addition, the development of carcinoma in about 25% of patients mandates cyst excision. Accordingly, excision of the cyst with biliary reconstruction by Roux-en-Y hepaticojejunostomy and diversion of the flow of pancreatic juice through the ampulla of Vater is currently the standard treatment. Sclerosing cholangitis causes fibrosis of bile ducts both within and outside the liver. This process, which is poorly understood, causes strictures in the duct system, characteristically with normal or dilated segments between strictures. Unfortunately, this anatomic arrangement does not lend itself to biliary reconstructive procedures. Each case must be analyzed, however, because in some patients the anatomic situation may lend itself to balloon dilatation or reconstruction. When the gallbladder appears to be absent, a search should be made for an ectopically located organ in the retroduodenal area, within the falciform ligament, and within the substance of the right lobe of the liver. With true gallbladder agenesis the common duct may be dilated, and choledocholithiasis is present in about one fourth of those who undergo operation. Therefore, operative needle cholangiography should always be done. Dissection of a long, fused cystic duct is fraught with hazard because the cystic and common ducts may share a common wall and serious duct damage may occur. The cystic duct should be ligated and divided immediately proximal to the area of fusion.

Because of the high complication rate and the long-term failure rate, the PVS is used only when other, more lasting options for therapy either are not available or are contraindicated. The chronic alcoholic patient may benefit from a peritoneovenous shunt because his ascites is the dominant problem related to his chronic liver disease, and persistent alcoholism is a contraindication to liver replacement in most centers. PVS may be quite effective for the temporary management of acute intractable postoperative ascites, such as in patient A; however, it is absolutely contraindicated in the presence of infection. Patient B has ascites as her dominant problem as well; however, with PBC as the underlying liver disease, she is an excellent candidate for transplantation. Patient D also has ascites as the major problem; however, the side-to-side portosystemic shunt is a far better long-term treatment option than PVS.

Insulinoma is the most common endocrine tumor of the pancreas. Insulinoma is associated with Whipple's triad, which consists of (1) symptoms of hypoglycemia at fasting; (2) documentation of blood glucose levels of less than 50 mg. per dl.; and (3) relief of symptoms following administration of glucose. The most reliable method for diagnosing insulinomas is a monitored fast. Neither an oral or an intravenous glucose tolerance test is indicated in the majority of patients being evaluated for insulinoma. Support for the diagnosis of insulinoma can come from documenting elevated C peptide and proinsulin levels. Screening for anti-insulin antibodies is indicated to rule out the possibility of surreptitious insulin administration. Tumor localization is typically performed with CT, endoscopic ultrasonography, or angiography. ERCP is not indicated for evaluation of most pancreatic endocrine tumors, as the tumors only rarely communicate with the main pancreatic duct system. As many as 90% of patients with insulinoma have benign solitary pancreatic adenomas amenable to surgical cure.

Over the past 10 years, detailed anatomic description of the hepatic veins, portal pedicles, and the inferior vena cava have been possible through the use of intraoperative ultrasound. Cooperation between radiologists and hepatic surgeon with the use of intraoperative ultrasound has allowed the identification of lesions during surgery that were not visible by conventional transcorporial ultrasound or CT scanning. Beginning superiorly at the inferior vena cava, the confluence and course of each of the hepatic veins can easily be determined. More inferiorly, the main right and left portal pedicles can be seen coursing transversely in the transverse scissura. Portal structures can easily be differentiated from hepatic veins by the hyperechoic extensions of Glisson’s capsule which surround these structures. When a circular structure is encountered, a mass or metastasis may be suspected. Scanning away from the mass may reveal a tubulovascular shape which has been imaged and cross sectioned. Flattening of the circular mass by external compression with the ultrasound probe will also differentiate a vascular structure from a solid mass.

The common causes of pancreatic abscesses are infected pancreatic pseudocysts and necrotizing pancreatitis. The diagnosis is suggested by persistent fever, leukocytosis, and a palpable abdominal mass. Bacteremia and systemic toxicity are late clinical features. Percutaneous aspiration with positive cultures is the definitive preoperative test, facilitated by CT scanning or ultrasound-guidance to suspicious peripancreatic fluid collections. When diagnosed, the treatment of choice is wide surgical débridement with removal of all infected and revitalized tissues. Generous drainage is mandatory. One of the major sources of morbidity and mortality in this situation is the late development of mycotic visceral pseudoaneurysms, particularly involving the splenic circulation. These may be complex management problems, requiring angiographic embolization or other innovative treatment strategies.

It is true that gallstone ileus occurs mostly in elderly women and should always be suspect when small bowel obstruction presents in this age group. The great majority of cases of gallstone ileus are preceded by a spontaneous fistula occurring between the gallbladder and duodenum, allowing gallstones to enter the intestinal tract, which can potentially block the terminal ileum. Finding air within the biliary tree should always arouse suspicion of the possibility of this diagnosis when it is associated with a radiographic pattern of small bowel obstruction. The initial part of the operative approach to this disease is to relieve the bowel obstruction by performing an enterotomy just proximal to the point of obstruction to remove the stone. Where possible, definitive repair of the fistula should be undertaken to avoid recurrent obstruction and to obviate the possible recurring complications of cholangitis. Percutaneous drainage of bile collections combined with endoscopic papillotomy may be sufficient treatment for external and internal biliary fistulas but is never an allowable approach in the presence of gallstone ileus with small bowel obstruction. Relief of the obstruction is mandated in this setting.

Adenomas typically enlarge and cause symptoms, may rupture, and have a definite malignant potential. Therefore they should generally be resected when found. FNH is not a true neoplasm and generally has an uneventful course. Both are related to BCPs, although the relationship of adenoma is more firmly established. While small bile duct hamartomas are much more common, hemangiomas are the most common lesion to come to the attention of surgeons. They should not generally be biopsied because of possible hemorrhage. By definition, nodular regenerative hyperplasia occurs in the absence of cirrhosis.

Shunt operations are the most effective means of preventing recurrent variceal hemorrhage. Rebleeding rates after endoscopic sclerotherapy range from 40% to 60%. Although extensive esophagogastric devascularization has effectively prevented recurrent bleeding in Japanese series, these operations have been followed by rebleeding rates in excess of 25% in most Western series. Although one controlled trial has shown more frequent recurrent hemorrhage following the distal splenorenal shunt than after the portacaval shunt, most series have reported rebleeding rates of less than 10% for both of these operations. Both the liver and the splanchnic viscera are important sites of ascites formation. Since the distal splenorenal shunt maintains sinusoidal and mesenteric venous hypertension and requires interruption of important retroperitoneal lymphatics, it tends to aggravate rather than relieve ascites. Hepatic sinusoidal pressure may be unchanged or even increased after an end-to-side portacaval shunt. Only side-to-side portal-systemic shunts, such as the side-to-side portacaval shunt, reliably decompress both the liver and splanchnic viscera, thus preventing ascites formation.

Peritoneal lavage as a specific therapy for acute pancreatitis was proposed after experimental studies demonstrated improved survival in animals with fulminant pancreatitis. The concept was appealing in that activated proteases and other vasoactive substances identifiable in peritoneal aspirates from patients with pancreatitis would be removed, rather than systemically absorbed. Unfortunately, clinical trials using this approach have produced disappointing results, and the eventual overall mortality rate appears unchanged.

Cavernous hemangiomas of the liver are the most common benign hepatic tumor and are detected in some 2% to 7% of autopsies. Overall, hemangiomas are exceeded only by hepatic metastases as the most common hepatic tumor. Cavernous hemangiomas consist histologically of cystically dilated, endothelium-lined vascular spaces. They occur in all ages but are observed more commonly in females. Hemangiomas are not premalignant. Less than half of affected patients have symptoms. Those that have symptoms usually have large masses. Symptoms usually occur including vague right upper quadrant discomfort, pain, fullness, and early satiety. Physical examination may be notable for hepatomegaly, mass or bruit. There are no laboratory abnormalities in patients with hemangiomas. The most useful radiologic test for diagnosing hemangiomas are MRI, CT and tagged red blood cell scanning. These tests have largely replaced angiography. CT with vascular contrast often demonstrates a diagnostically characteristic enhancement pattern. Gadilinium-enhanced MRI has recently been shown to be sensitive and specific in the diagnosis of hemangioma and has better resolution than tagged red blood cell scans. FNA biopsy of suspected hemangiomas can be performed, however this procedure should be avoided if the diagnosis is secure using noninvasive procedures. Given the natural history of hemangiomas and its low risk of rupture, observation is indicated for asymptomatic patients, especially for lesions smaller than 4 cm. Surgical excision is the only consistently effective treatment for symptomatic masses and should be performed if the lesion is localized and accessible with an acceptable operative risk. Embolization is indicated only for unresectable lesions and is only modestly effective

The operative treatment for pseudocysts depends on the underlying cause of the cyst, as well as the size, location, and maturity of the pseudocyst wall. Whenever possible, the status of the pancreatic duct should be assessed preoperatively, preferably by ERCP. Operative drainage can be either external or internal. External drainage is chosen in the presence of infection or an immature capsule. The disadvantages of external drainage include the risk of pancreatic fistula formation and a pseudocyst recurrence. External drainage has been associated with a higher mortality rate, probably because it is used in patients at higher risk, especially those with sepsis, pancreatic abscesses, or ruptured pseudocysts.
The type of internal drainage procedure selected depends on the location of the pseudocyst and whether or not there is associated pancreatic ductal pathology. Cystogastrostomy is the simplest and safest alternative if the pseudocyst is appropriately adjacent to the posterior wall of the stomach. Cystojejunostomy using a Roux-en-Y or loop jejunostomy may also be appropriate, depending on the location and specific anatomy of the pseudocyst. Pancreatic resection is associated with the lowest recurrence rate (3%), but is limited to pseudocysts occurring in the tail of the pancreas

Pain is a predominant symptom complex in most patients with chronic pancreatitis. Chronic pancreatic pain is usually localized to the epigastrium with radiation to the back in the region of the upper lumbar vertebrae. Discomfort may be exacerbated by eating and is usually alleviated by abstinence from food and by bending forward. Malabsorption and weight loss, clinical manifestations of steatorrhea, are only observed when greater than 90% of exocrine tissue has been destroyed. Clinical signs of malabsorption are a late manifestation of chronic pancreatitis. Although abnormal glucose tests can be demonstrated in 50% to 70% of patients with chronic Pancreatitis: overt diabetes mellitus is present in only 30% to 40%. Endocrine deficits are usually progressive. If individual patients are repetitively tested, progressive deterioration is often observed.

The treatment of insulinoma is surgical in nearly all cases. Insulinomas are found evenly distributed within the pancreas, with approximately one-third being located in the head and uncinate process, one-third in the body of the gland, and one-third in the tail of the gland. Ninety percent of patients will be found to have benign solitary adenomas amenable to surgical cure. Small benign insulinomas not in close proximity to the main pancreatic duct may be removed by enucleation, independent of their location within the gland. In the body and tail of the Pancreas: insulinomas greater than 2 cm in diameter, and those in close proximity to the pancreatic duct are most commonly excised by distal pancreatectomy. Large insulinomas deep in the head or uncinate process of the pancreas may not be amenable to local excision, and may require pancreaticoduodenectomy.

It is true that gallstone ileus occurs mostly in elderly women and should always be suspect when small bowel obstruction presents in this age group. The great majority of cases of gallstone ileus are preceded by a spontaneous fistula occurring between the gallbladder and duodenum, allowing gallstones to enter the intestinal tract, which can potentially block the terminal ileum. Finding air within the biliary tree should always arouse suspicion of the possibility of this diagnosis when it is associated with a radiographic pattern of small bowel obstruction. The initial part of the operative approach to this disease is to relieve the bowel obstruction by performing an enterotomy just proximal to the point of obstruction to remove the stone. Where possible, definitive repair of the fistula should be undertaken to avoid recurrent obstruction and to obviate the possible recurring complications of cholangitis. Percutaneous drainage of bile collections combined with endoscopic papillotomy may be sufficient treatment for external and internal biliary fistulas but is never an allowable approach in the presence of gallstone ileus with small bowel obstruction. Relief of the obstruction is mandated in this setting.

The steps involved in a right hepatic lobectomy involve adherence to the tenet of optimal operative exposure and control of vascular inflow and outflow. In select circumstances, control of the vena cava may be desired. Either the individual portal structures can be identified and ligated early in the course of the procedure, or simply the entire portal triad can be circled with an umbilical tape tourniquet in preparation for the Pringle maneuver. If temporary portal inflow occlusion is used, intermittent 10 to 20 minute intervals of clamping with 3 to 5 minutes to reestablish blood flow is recommended. The division of the hepatic parenchyma begins with scoring of Glisson’s capsule with cautery or knife and proceeds with division of the hepatic surface using either blunt dissection by finger fracture, the blunt edge of an instrument or suction tip, or using an ultrasonic dissector. Individual vessels and bile ducts are cauterized, sutured, or clipped in rapid succession from anterior to posterior. The hepatic veins are encountered in the hepatic substance near the vena cava and are carefully clamped and suture ligated to complete the resection. In addition, there are also several posterior accessory veins (up to 10 in number) which drain the medial aspect of the right lobe and empty directly into the right anterior surface of the IVC.

Patients characteristically present with intermittent severe diarrhea, typically of a watery nature, averaging 5 liters/day. Malabsorption and steatorrhea are not common. Hypokalemia results from the fecal loss of large amounts of potassium (up to 400 meq/day), and low serum potassium levels may be associated with muscular weakness, lethargy, and nausea. Most patients are hypochlorhydric or achlorhydric. Half of the patients have some degree of hyperglycemia and hypercalcemia, while cutaneous flushing can be observed in a minority of patients. The diagnosis of VIPoma is typically made after excluding other more common causes of diarrhea. The active agent in the VIPoma syndrome is usually vasoactive intestinal polypeptide (VIP), with a minority of patients having elevations of other candidate mediators such as peptide histidine-isoleucine (PHI) or prostaglandins.

Most bile duct cancers are discovered after they are incurable, and only a tiny subset of resected proximal lesions are cured. The more distal the lesion, the more likely is resection to achieve cure (e.g., approximately 30% 5-year survival for periampullary lesions as compared with 0% to 10% for hilar lesions). The use of adjuvant or primary radiation remains controversial because of the heterogeneity of the patient populations on which this modality has been used. Because of the localized nature of this disease it would seem that transplantation would produce favorable results; however, this has not been the case.

The conventional splenorenal shunt and side-to-side portacaval shunts completely divert portal flow away from the liver (nonselective shunts). The distal splenorenal shunt is a selective shunt that preserves hepatic portal perfusion in the majority of patients; however, the magnitude of portal flow is decreased because the gastrosplenic component is diverted into the renal vein. Additionally, many patients (especially alcoholic cirrhotics) develop collaterals between the mesenteric venous circulation and the shunt, resulting in gradual attrition of the remaining portal flow. Although there have been anecdotal reports of portal vein thrombosis after endoscopic sclerotherapy, two controlled trials have demonstrated better preservation of hepatic portal perfusion in sclerotherapy patients than in persons who receive the distal splenorenal shunt

The optimal management of individual patients with asymptomatic gallstones has been debated for years. Most evidence, although still somewhat controversial, would indicate that the natural history of asymptomatic gallstones is benign and that early or prophylactic cholecystectomy, either laparoscopic or otherwise, is rarely indicated. It is suggested that less than 10% of patients with asymptomatic gallstones will develop significant symptoms over a five year period. Similarly, medical dissolution with oral agents, extracorporial biliary lithotripsy, or contact dissolution, is not indicated in these patients. The risk of gallbladder cancer is so low as to not warrant cholecystectomy in asymptomatic patients.

The prognosis for gallbladder cancer remains poor, with an average survival in the range of six months. Less than 5% of patients survive five years because 90% of gallbladder cancer patients present with stage V disease. For stage V disease, the goal of treatment is palliation. If these patients present with obstructive jaundice, a major goal of treatment is relief of jaundice and its attendant symptoms such as pruritus and cholangitis. Although radiation and chemotherapeutic regimens have been tried, none have been associated with a good response.

By far the most common cause of hemobilia is trauma. Tumors also may cause the syndrome but are relatively uncommon causes. For severe hemobilia the best therapy is arteriographic embolization. Usually the site of bleeding or a false aneurysm can be identified. Operation should be reserved as a last resort or when the condition is recognized intraoperatively. Percutaneous cholangiography–associated intrabiliary hemorrhage is usually, but not always, minor and self-limiting. Ultrasonography is a very nonspecific diagnostic technique for hemobilia. Arteriography remains the best diagnostic method.

In the past, choledochal cyst was treated by Roux-en-Y cystojejunostomy, but long-term results were poor. Excision of the cyst is essential to prevent recurrent pancreatitis. In addition, the development of carcinoma in about 25% of patients mandates cyst excision. Accordingly, excision of the cyst with biliary reconstruction by Roux-en-Y hepaticojejunostomy and diversion of the flow of pancreatic juice through the ampulla of Vater is currently the standard treatment. Sclerosing cholangitis causes fibrosis of bile ducts both within and outside the liver. This process, which is poorly understood, causes strictures in the duct system, characteristically with normal or dilated segments between strictures. Unfortunately, this anatomic arrangement does not lend itself to biliary reconstructive procedures. Each case must be analyzed, however, because in some patients the anatomic situation may lend itself to balloon dilatation or reconstruction. When the gallbladder appears to be absent, a search should be made for an ectopically located organ in the retroduodenal area, within the falciform ligament, and within the substance of the right lobe of the liver. With true gallbladder agenesis the common duct may be dilated, and choledocholithiasis is present in about one fourth of those who undergo operation. Therefore, operative needle cholangiography should always be done. Dissection of a long, fused cystic duct is fraught with hazard because the cystic and common ducts may share a common wall and serious duct damage may occur. The cystic duct should be ligated and divided immediately proximal to the area of fusion.

Patients presenting in the early postoperative period with a biliary leak may be septic with either cholangitis or intra-abdominal bile collections. Sepsis must be controlled first with broad-spectrum parenteral antibiotics, cholangiography with percutaneous biliary drainage and percutaneous or operative drainage of biliary leaks. Once sepsis is controlled, there is no hurry in proceeding with surgical reconstruction of the bile duct stricture. The combination of proximal biliary decompression and external drainage allows most biliary fistulas to be controlled or even closed. At that time the external drains may be removed. The patients can then be discharged to home to allow several months to lapse for resolution of the inflammation in the periportal region and recovery of overall health status.

Metabolic alkalosis and hypokalemia are common in patients with cirrhosis because they often have associated secondary hyperaldosteronism (especially those with ascites), diarrhea, and frequent emesis. Hyperaldosteronism enhances H+ and K+ exchange for Na+ in the distal tubule of the kidney. The cause of diarrhea in patients with cirrhosis is unknown, but malabsorption secondary to splanchnic venous hypertension may be a contributing factor. Emesis is common in alcoholic cirrhotics and patients with tense ascites. Deleterious effects of metabolic alkalosis include impaired tissue oxygen delivery secondary to shift of the oxyhemoglobin dissociation curve to the left and conversion of ammonium chloride to ammonia, which may contribute to encephalopathy.

It is true that gallstone ileus occurs mostly in elderly women and should always be suspect when small bowel obstruction presents in this age group. The great majority of cases of gallstone ileus are preceded by a spontaneous fistula occurring between the gallbladder and duodenum, allowing gallstones to enter the intestinal tract, which can potentially block the terminal ileum. Finding air within the biliary tree should always arouse suspicion of the possibility of this diagnosis when it is associated with a radiographic pattern of small bowel obstruction. The initial part of the operative approach to this disease is to relieve the bowel obstruction by performing an enterotomy just proximal to the point of obstruction to remove the stone. Where possible, definitive repair of the fistula should be undertaken to avoid recurrent obstruction and to obviate the possible recurring complications of cholangitis. Percutaneous drainage of bile collections combined with endoscopic papillotomy may be sufficient treatment for external and internal biliary fistulas but is never an allowable approach in the presence of gallstone ileus with small bowel obstruction. Relief of the obstruction is mandated in this setting.

Mucinous cystic neoplasms account for about 2% of pancreatic exocrine tumors. Most patients with mucinous cystic tumors present with abdominal pain or an abdominal mass. There may be associated weight loss, steatorrhea, or diabetes. The diagnosis is best made by CT scanning and ultrasonography, which demonstrate a mass containing fluid-filled structures and internal septations. Occasionally, it is possible to see the papillary tumor excrescences on the cyst walls.
The tumor occurs six times as often in females as in males. About 80% of the tumors are located in the body and tail of the pancreas. They present as large (average, 10 cm), soft, and somewhat irregular tumors. Microscopically, the cysts are lined by columnar epithelium which contains mucin. Although most of the cells may appear benign histologically, most tumors larger than 3 cm contain areas of premalignant or malignant change and all mucinous cystic tumors should be considered to have malignant potential.

Uncontrolled sepsis and the consequent multisystem organ failure are the life-threatening sequelae of acute toxic cholangitis. Thus, the initial goal of treatment is to decompress the biliary duct system to prevent reflux of bacteria and their toxic products into the circulation. This can be done by intubating the duct system through the percutaneous, transhepatic, or the endoscopic route or by insertion of a T tube in the common duct at operation. Removal of the stone causing the obstruction is not necessary to stabilize the patient. Only after the duct is decompressed should the cause of the obstruction be addressed. When transhepatic biliary drainage has been used, endoscopic or surgical removal of the stone can be carried out after the patient has recovered completely. When initial therapy is sphincterotomy, the stone should be removed as part of the procedure. Often the stone falls out without manipulation. If surgical placement of a T tube is the initial treatment, the stone should be removed only if it is convenient to do so. The long-range goal of treatment of patients with bile duct obstruction is to prevent cirrhosis, ascites, portal hypertension, and hemorrhage from esophageal varices; however, death from sepsis is the immediate threat in acute toxic cholangitis. Gallstone pancreatitis may occur in patients who have an impacted stone in the distal duct, independent of the presence or absence of acute toxic cholangitis; however, gallstone pancreatitis is more often associated with the passage of a stone into the duodenum.

Chronic pancreatitis is a clinical entity that includes recurrent or persistent abdominal pain with evidence of exocrine and endocrine pancreatic insufficiency. While chronic pancreatitis may result from repeated episodes of acute pancreatitis, not all patients with recurring acute pancreatitis progress to chronic pancreatitis. The most common causes of chronic pancreatitis include alcohol abuse, hyperparathyroidism, congenital anomalies of the pancreatic duct, pancreatic trauma, and cystic fibrosis. The most useful radiographic tests in patients with suspected chronic pancreatitis are CT and endoscopic retrograde cholangiopancreatography (ERCP). Mesenteric angiography has no role in the evaluation of most patients with chronic pancreatitis. Patients with disabling chronic pancreatitis who require operative intervention are candidates for a longitudinal pancreaticojejunostomy (Peustow procedure) if pancreatography demonstrates a dilated pancreatic duct. Total pancreatectomy is rarely performed because of the significant problems associated with labile insulin sensitivity, steatorrhea, and weight loss.

When patients with chronic pancreatitis have pancreatic ductal dilatation (greater than 8 mm. ductal decompression using longitudinal pancreaticojejunostomy may be employed for relief of pain. The finding that pancreatic ductal hypertension exists in patients with painful chronic pancreatitis and that surgical decompression reduces intrapancreatic pressure to normal provides the rationale for this operation. The anterior surface of the pancreas is exposed through the lesser sac. The entire pancreatic duct is opened from the pancreatic tail to a point 1 cm from the duodenum. A side-to-side anastomosis is then performed between the opened pancreatic duct and a loop of jejunum. Splenectomy is not necessary. In-hospital mortality rates of less than 5% have been widely reported. Approximately 80% of patients report complete or substantial improvement of pain following longitudinal pancreaticojejunostomy

A patient who has simple cholelithiasis and an episode of acute pancreatitis is usually treated nonoperatively until clinical resolution of the pancreatitis occurs. The rate of recurrent biliary pancreatitis is as high as 34% to 56% within 6 weeks; therefore, an aggressive operative approach is appropriate. Cholecystectomy is often performed after the resolution of acute pancreatitis but before hospital discharge. Common bile duct instrumentation in this setting has a substantially increased risk of recurrent acute pancreatitis.

The Sugiura procedure consists of devascularization of the esophagus to the inferior pulmonary vein and the proximal two thirds of the stomach, splenectomy, and distal esophageal transection. The devascularization component should be done as close to the esophagus and stomach as possible. The coronary vein and paraesophageal collaterals are preserved to maintain an effective portal-systemic collateral pathway and thereby discourage reformation of varices.

Because of the high complication rate and the long-term failure rate, the PVS is used only when other, more lasting options for therapy either are not available or are contraindicated. The chronic alcoholic patient may benefit from a peritoneovenous shunt because his ascites is the dominant problem related to his chronic liver disease, and persistent alcoholism is a contraindication to liver replacement in most centers. PVS may be quite effective for the temporary management of acute intractable postoperative ascites, such as in patient A; however, it is absolutely contraindicated in the presence of infection. Patient B has ascites as her dominant problem as well; however, with PBC as the underlying liver disease, she is an excellent candidate for transplantation. Patient D also has ascites as the major problem; however, the side-to-side portosystemic shunt is a far better long-term treatment option than PVS.

Serum glucose is tightly regulated by the liver despite wide fluctuations in dietary ingestion. The liver can take up as much as 100 g/day of glucose and convert it to glycogen by the process of glycogenesis. The liver can also release glucose into the blood by glycogenolysis, the breakdown of glycogen, or by gluconeogenesis, the formation of new glucose from substrates such as alanine, lactate, glycerol or dietary amino acids. Hormones play a key role in hepatic regulation of glucose metabolism. Insulin, for example, stimulates glycogenesis, and glucagon stimulates glycogenolysis and gluconeogenesis. Gluconeogenesis is also enhanced by fasting, critical illness and periods of anaerobic metabolism.
Glycogen is a complex polymer of glucose. Liver cells can store up to 8% of their weight as glycogen. The first step in glycogen storage is the transport of glucose through the hepatocyte plasma membrane. About 90% of portal venous glucose is removed from the blood by liver cells through carrier-facilitated diffusion. The rate of glucose transport is enhanced by insulin. Once in the hepatocyte, glucose and ATP are converted by the enzyme glucokinase to glucose-6-phosphate (G6P), the first intermediate in the synthesis of glycogen. Because complete oxidation of one molecule of G6P generates 37 molecules of ATP, and storage only uses one molecule of ATP, the overall efficiency of glucose storage in glycogen is a remarkable 97%. Glycolysis is the pathway by which glucose is converted to two molecules of pyruvate and occurs in the cytoplasm in contrast to the citric acid cycle which occurs in the mitochondria.

Prior to the introduction of laparoscopic cholecystectomy, there was tremendous enthusiasm for a number of nonsurgical techniques for managing gallstones. Dissolution of existing gallstones with pharmacologic agents has been addressed by several national cooperative studies. Ursodeoxycholic acid is the best, safest, and most effective commerically available drug currently available. However, it still has a rate of complete dissolution of only 40%. It is also estimated that only 10% of patients will be suitable candidates for this therapy. Furthermore, gallstone recurrence is a major problem. Actuarial life table analysis indicates that the risk of gallstone recurrence in patients who have undergone dissolution of gallstones with oral bile acid therapy is 50% by five years.
The addition of extracorporial shock wave lithotripsy increases the efficiency of gallstone clearance and in selected patients complete fragment clearance can be obtained in over 90% of patients by one year. However, optimal results can be obtained only by setting relatively strict criteria for inclusion. In applying such criteria, less than 20% of patients in the United States would be considered eligible for ESWL. Similar problems with gallstone recurrence have been observed with this technique. Finally, contact dissolution primarily with the ether solvent methyl tert-butyl ether (MTBE) is extremely effective in dissolving cholesterol gallstones. This technique, however, will work only in stones which are composed of cholesterol and the patient must have a demonstrably patent cystic duct before considering this treatment. As with oral dissolution and lithotripsy, gallstone recurrence will remain a problem with this technique.

The diagnosis of acute (fulminant) hepatic failure is based on the development of encephalopathy within eight weeks of the onset of symptoms. The overall prognosis is poor, but the hepatic lesions are potentially reversible, and recovery can lead to restoration of normal liver function. The most frequent cause of acute hepatic failure world-wide is non-A, non-B viral hepatitis. A variety of other viral agents and hepatotoxins can also cause this condition.
No reliable criteria predict outcome and response to treatment. Higher grades of encephalopathy (depth of coma) on admission are associated with the worst prognosis. Management should include general supportive measures and specific treatment for hepatic encephalopathy, cerebral edema, electrolyte and metabolic disturbances, infection, and pain. Hypoglycemia is an unusual complication of most liver diseases except in patients with acute hepatic failure or hepatic neoplasms. The enormous reserve capacity of the liver accounts for the rarity of hypoglycemia except as a preterminal event. Bleeding is also a frequent cause of death in patients with acute hepatic failure secondary to depressed liver synthesis of clotting factors and qualitative or quantitative platelet disorders. The lack of a definitive medical treatment for acute hepatic failure makes liver transplantation seem attractive especially for patients with little or no chance of recovering normal liver function. Perhaps the most significant drawback to widespread acceptance of liver transplantation for acute hepatic failure is the lack of criteria reliability to predict which patients are likely to benefit from operation. Patients with mild to moderate degrees of coma are likely to recovery spontaneously without the need for liver transplantation while rapid deterioration and neurologic status to grade III or grade IV coma are associated in some centers with a mortality of 95%.

Orally administered glucose stimulates a greater insulin response than an equivalent amount of intravenous glucose through the release of enteric hormones that potentiate insulin secretion. This effect is known as the enteroinsular axis. Gastric inhibitory polypeptide (GIP) appears to be an important regulator of this effect, although other gut peptides, such as glucagon-like peptide I (GLP-1), may contribute to this effect as well. Nutrients that regulate insulin secretion include amino acids, such as arginine, lysine, and leucine, and free fatty acids. Hormones that stimulate insulin secretion include glucagon, GIP, and cholecystokinin, whereas somatostatin, amylin, and pancreastatin are inhibitory. Insulin is also stimulated by sulfonylurea compounds, which act independently of the glucose concentration and form the basis of treatment of type II, or insulin-independent, diabetes.

Biliary complications involving the common bile duct can occur in chronic pancreatitis because of the intimate association of that structure with the head of the pancreas. In two-thirds of individuals, the common bile duct traverses the pancreatic parenchyma and in an additional 25%, the common bile duct lies within a groove along the posterior surface of the pancreas. Fibrosis associated with chronic pancreatitis can encase and compress the common bile duct. Common bile duct stenosis is relatively common in chronic pancreatitis, occurring in approximately 10% of cases observed long-term. Cholangiography typically reveals a long, gradually tapering stricture conforming to the intrapancreatic portion of the common bile duct. In contrast, malignant strictures usually result in abrupt termination of the biliary duct. The proximal suprapancreatic portion of the bile duct is variably dilated

When jaundiced patients undergo exploration in the hopes of resection but unresectable disease is found, biliary bypass should be performed. The jejunum is typically chosen as a conduit in preference to the duodenum because duodenal obstruction may occur as the tumor becomes more advanced. There has been much discussion over the use of the bile duct or the gallbladder for biliary decompression. Operative mortality and mean survival (about 6 months) do not differ between patients with cholecystojejunostomy and choledochojejunostomy. Recurrent jaundice is more common after cholecystojejunostomy. Because recurrent jaundice constitutes a failure of palliation, the use of the common duct for biliary bypass is preferable in most patients. There are circumstances, however, in which it may be more appropriate to use the gallbladder. Such instances include patients with poor performance status, cases in which the tumor is bulky and invades the porta hepatis, or when periductal varices have developed as a result of portal vein thrombosis. The suitability of the gallbladder as a biliary conduit must be proven intraoperatively. If, on aspiration, the gallbladder contains colorless fluid, the cystic duct may be assumed to be obstructed, and the gallbladder should be removed and not used for bypass. If there is green bile in the gallbladder, patency of the cystic duct should be proved by cholangiography before a bypass is performed.

About two-thirds of patients with portal hypertension develop varices; of these only two-thirds subsequently experience variceal hemorrhage. A number of factors are important in the pathogenesis of variceal hemorrhage. These include portal pressure, intravariceal pressure, variceal size and structure, and other factors. Variceal size alone is not predictive of variceal hemorrhage. Evidence conflicts about whether erosive esophagitis is a cause of variceal rupture. Control of acid reflux by H2 blockade has not been shown to decrease the incidence of rebleeding after esophageal hemorrhage.

Generally, a pancreatic pseudocyst can be observed for a period of weeks or months in an effort to allow for spontaneous resolution. Percutaneous ultrasound-or CT-directed aspiration or drainage catheter placement is an initial treatment option. Simple aspiration is performed if the initial aspirate is sterile; if the aspirate is infected, a catheter or open drainage procedure is appropriate. Determination of pancreatic ductal anatomy is important. Contrast injection into the pseudocyst at the time of aspiration should be considered to assess the possibility of pancreatic ductal communication and obstruction, or multiple cysts. The pseudocyst recurrence rate after simple aspiration is about 20% to 25%.

Gastrinoma patients whose localization and staging studies are indicative of unresectable hepatic metastases should undergo percutaneous or laparoscopically-directed liver biopsy for histologic verification. If unresectable gastrinoma is confirmed, then open surgical exploration is not performed and the patient is maintained on long-term omeprazole therapy. Virtually all patients can be rendered achlorhydric with appropriate dose adjustment of omeprazole. Noncompliant patients who refuse to take appropriate doses of omeprazole and who develop complications related to their ulcer diathesis may require total gastrectomy for management. Total gastrectomy removes the end organ (parietal cell mass) and was once the procedure of choice for gastrinoma. Today its use in gastrinoma patients has markedly declined.

Biopsy of a liver mass can be done percutaneously (with or without CT or ultrasound guidance), laparoscopically, or at laparotomy. The biopsy may be done for cytology only (FNA) or for histology (larger-core biopsy). Guided FNA has an overall sensitivity of 77% to 94% and may allow a distinction between primary and secondary malignancy. The risks associated with needle biopsy include bleeding, infection, needle track seeding of tumor, and sampling error. Hypervascular masses, coagulopathy, and ascites are contraindications to percutaneous core biopsy, however, FNA biopsy is generally considered safe under these circumstances. In evaluation of any liver mass, percutaneous biopsy should be performed only if it can reasonably be expected to obviate the need for exploratory laparotomy. Biopsy of suspected primary metastatic malignancy with clinical indications of unresectability may spare the patient an unnecessary laparotomy. Laparoscopy with biopsy may also be used to evaluate liver masses and to possibly avoid laparotomy in patients considered to be borderline resectable.

The steps involved in a right hepatic lobectomy involve adherence to the tenet of optimal operative exposure and control of vascular inflow and outflow. In select circumstances, control of the vena cava may be desired. Either the individual portal structures can be identified and ligated early in the course of the procedure, or simply the entire portal triad can be circled with an umbilical tape tourniquet in preparation for the Pringle maneuver. If temporary portal inflow occlusion is used, intermittent 10 to 20 minute intervals of clamping with 3 to 5 minutes to reestablish blood flow is recommended. The division of the hepatic parenchyma begins with scoring of Glisson’s capsule with cautery or knife and proceeds with division of the hepatic surface using either blunt dissection by finger fracture, the blunt edge of an instrument or suction tip, or using an ultrasonic dissector. Individual vessels and bile ducts are cauterized, sutured, or clipped in rapid succession from anterior to posterior. The hepatic veins are encountered in the hepatic substance near the vena cava and are carefully clamped and suture ligated to complete the resection. In addition, there are also several posterior accessory veins (up to 10 in number) which drain the medial aspect of the right lobe and empty directly into the right anterior surface of the IVC.

In 90% of individuals, the main pancreatic duct, or duct of Wirsung, runs the entire length of the pancreas and joins the common bile duct to empty into the duodenum at the ampulla of Vater. The pancreatic duct is 2 to 3.5 mm in diameter and contains 20 secondary branches, which drain the tail, body, and uncinate process. The drainage of the lesser duct, or duct of Santorini, is variable. The lesser duct commonly drains the superior portion of the head of the pancreas. It empties separately into the second portion of the duodenum through the lesser papilla located 2 cm proximal to the ampulla of Vater. Pancreas divisum results from an incomplete fusion of the ventral pancreatic duct with the dorsal duct during fetal development and is present in 5% of patients. In this anomaly, the lesser duct drains the entire pancreas via an accessory ampulla located proximal to the ampulla of Vater. Inadequacy of this pattern of drainage can result in chronic pain.

Adenocarcinoma of the pancreas is newly diagnosed in approximately 28,000 patients in the United States every year. It is the fifth most common cause of cancer death in the United States, exceeded only by lung, colorectal, breast, and prostate cancer. The majority of cases of adenocarcinoma of the pancreas occur in the head of the gland, and if resectable, are treated via pancreaticoduodenectomy. Recent studies have shown that factors favoring long-term survival after pancreaticoduodenectomy for adenocarcinoma of the head of the pancreas include negative nodal status, negative margin status, small tumor diameter, and diploid DNA content. No accurate screening tests for adenocarcinoma of the pancreas are currently available. The best serologic test appears to be the CA 19–9, which is elevated in the majority of patients with adenocarcinoma of the head of the pancreas. Unfortunately, the test is not sufficiently sensitive or specific, and further screening tests are needed.

The proper treatment is surgical removal of the tumor; aggressive pancreatic resection is appropriate. It is crucial to avoid mistaking a mucinous cystic tumor for a pancreatic pseudocyst. Internal drainage of a malignant mucinous cystic tumor results in catastrophic tumor dissemination and should never be performed. With appropriate treatment, all patients with histologically benign tumors should be cured; for tumors demonstrating malignant change, 5-year survival after surgery is about 60%.

Radical resection, radiation therapy, and chemotherapy have been effective only anecdotally. Most believe that the dismal prognosis of carcinoma of the gallbladder does not justify anything more than palliative treatment. About 88% of patients are dead within a year of diagnosis, and only about 4% are alive after 5 years, regardless of the type of treatment. Those whose surgeon was unaware of the presence of the tumor at the time of cholecystectomy (approximately 12% of cases) are most likely to survive long term. There are insufficient data to support conclusively the proposition that the patient with unexpected carcinoma found on histologic examination should undergo reoperation with intent for radical excision. There also are indirect suggestions that the prognosis of gallbladder carcinoma may be improving, but it is not clear if this is spontaneous or due to either earlier diagnosis or surgical management.

Operative management of patients with stricture of the common bile duct associated with chronic pancreatitis is justified to treat symptoms and to prevent development of biliary cirrhosis. Operative indications include progressive jaundice, cholangitis, liver biopsy evidence of biliary cirrhosis, persistent elevation of alkaline phosphatase at greater than three times normal, and progressive stricture demonstrated by radiologically progressive dilatation of extrahepatic and intrahepatic biliary ducts. Both choledochoduodenostomy and choledochojejunostomy are excellent operative choices.

Bile is secreted by the liver and is composed primarily of water, electrolytes, and organic solutes. Bile salts, cholesterol, and phospholipids are the main solutes found within bile and account for about 80% of the dry weight of bile. Most of the cholesterol found in bile is synthesized de novo in the liver. Cholesterol is an organic molecule that is virtually insoluble in an aqueous medium such as bile. Therefore, mechanisms for maintaining cholesterol in solution have been evolved. For decades, the mixed micelle which is composed of the amphiphatic bile salts and phospholipid was considered the primary carrier of bile. More recently, it has been demonstrated that up to 70% of the total amount of cholesterol normally found in gallbladder bile is transported and solubilized in the vesicular form. Bile vesicles are composed primarily of phospholipid of which in the human, lecithin accounts of 90% of the phospholipid content

Acute cholecystitis occurs in about 10% to 20% of patients with symptomatic gallstones. Although the clinical manifestations of biliary colic and acute cholecystitis may overlap and clinical distinction is often difficult, persistence of pain beyond a matter of hours and fever would strongly suggest acute cholecystitis. The primary events in the development of acute cholecystitis are chemical in nature with bacterial infection playing a minor role in the genesis of the disease. In normal healthy subjects without gallstones, incidence of positive bile cultures is essentially zero. In contrast, between 30 and 70% of patients with the clinical diagnosis of acute cholecystitis will have positive bile cultures. The incidence of positive bile cultures who undergo cholecystectomy increases significantly with age.
Septic complications continue to be a significant source of morbidity after cholecystectomy for acute cholecystitis. These septic complications can best be prevented by the judicious use of appropriate antimicrobial agents. The goal of antimicrobial therapy should be establishment of adequate serum and tissue levels of antibiotic rather than selection of an antibiotic that is excreted into the bile. Given the bacteriology that is typical in patients with uncomplicated cholecystitis, an appropriate antibiotic regimen should provide for adequate coverage of gram-negative aerobes. Although technically more difficult, laparoscopic cholecystectomy can be completed safely in the majority of patients with acute cholecystitis. Significant experience and good judgment, however, is essential in insuring optimal results.
Laboratory data are often nonspecific with acute cholecystitis. Mild jaundice may be present in up to 20% of patients and is typically due to inflammation as opposed to bile duct obstruction secondary to stones.