Pancreatitis is a common nonbacterial inflammatory disease caused by activation, interstitial liberation, and autodigestion of the pancreas by its own enzymes. The process may or may not be accompanied by permanent morphologic and functional changes in the gland. Much is known about the causes of pancreatitis, but despite the accumulation of much experimental data, understanding of the pathogenesis of this disorder is still incomplete.
In acute pancreatitis, there is sudden upper abdominal pain, nausea and vomiting, and elevated serum amylase. Chronic pancreatitis is characterized by chronic pain, pancreatic calcification on x-ray, and exocrine (steatorrhea) or endocrine (diabetes mellitus) insufficiency. Attacks of acute pancreatitis often occur in patients with chronic pancreatitis. Acute relapsing pancreatitis is defined as multiple attacks of pancreatitis without permanent pancreatic scarring, a picture most often associated with biliary pancreatitis. The unsatisfactory term chronic relapsing pancreatitis, denoting recurrent acute attacks superimposed on chronic pancreatitis, will not be used in this chapter. Alcoholic pancreatitis often behaves in this way. The term subacute pancreatitis has also been used by some to denote the minor acute attacks that typically appear late in alcoholic pancreatitis.
Most cases of pancreatitis are caused by gallstone disease or alcoholism; a few result from hypercalcemia, trauma, hyperlipidemia, and genetic predisposition; and the remainder are idiopathic. Important differences exist in the manifestations and natural history of the disease as produced by these various factors.
About 40% of cases of pancreatitis are associated with gallstone disease, which, if untreated, usually gives rise to additional acute attacks. For unknown reasons, even repeated attacks of acute biliary pancreatitis seldom produce chronic pancreatitis. Eradication of the biliary disease nearly always prevents recurrent pancreatitis. The etiologic mechanism most likely consists of transient obstruction of the ampulla of Vater and pancreatic duct by a gallstone. Choledocholithiasis is found in only 25% of cases, but because over 90% of patients excrete a gallstone in feces passed within 10 days after an acute attack, it is assumed that most attacks are caused by a gallstone or biliary sludge traversing the common duct and ampulla of Vater. Other possible steps in pathogenesis initiated by passage of the gallstone are discussed below.
B. Alcoholic Pancreatitis
In the United States, alcoholism accounts for about 40% of cases of pancreatitis. Characteristically, the patients have been heavy users of hard liquor or wine; the condition is relatively infrequent in countries where beer is the most popular alcoholic beverage. Most commonly, 6 years or more of alcoholic excess precede the initial attack of pancreatitis, and even with the first clinical manifestations, signs of chronic pancreatitis can be detected if the gland is examined microscopically. Thus, alcoholic pancreatitis is often considered to be synonymous with chronic pancreatitis no matter what the clinical findings.
Acute administration of alcohol stimulates pancreatic secretion and induces spasm in the sphincter of Oddi. This has been compared to experiments that produce acute pancreatitis by combining partial ductal obstruction and secretory stimulation. If the patient can be persuaded to stop drinking, acute attacks may be prevented, but parenchymal damage continues to occur owing to persistent ductal obstruction and fibrosis.
Hyperparathyroidism and other disorders accompanied by hypercalcemia are occasionally complicated by acute pancreatitis. With time, chronic pancreatitis and ductal calculi appear. The increased calcium concentrations in pancreatic juice that result from hypercalcemia may prematurely activate proteases. They may also facilitate precipitation of calculi in the ducts.
In some patients—especially alcoholics—hyperlipidemia appears transiently during an acute attack of pancreatitis; in others with primary hyperlipidemia (especially those associated with elevated chylomicrons and very low density lipoproteins), pancreatitis seems to be a direct consequence of the metabolic abnormality. Hyperlipidemia during an acute attack of pancreatitis is usually associated with normal serum amylase levels, because the lipid interferes with the chemical determination for amylase; urinary output of amylase may still be high. One should inspect the serum of every patient with acute abdominal pain, because if it is lactescent, pancreatitis will almost always be the correct diagnosis. If a primary lipid abnormality is present, dietary control reduces the chances of additional attacks of pancreatitis as well as other complications.
In this condition, attacks of abdominal pain usually begin in childhood. Some affected families also have aminoaciduria, but this is not a universal finding. Diabetes mellitus and steatorrhea are uncommon. Chronic calcific pancreatitis develops eventually in most patients, and many patients become candidates for operation for chronic pain. Pancreatic carcinoma is more frequent in patients with familial pancreatitis.
In certain populations where dietary protein intake is markedly deficient, the incidence of chronic pancreatitis is high. The reason for this association is obscure, especially in view of the observation that pancreatitis afflicts alcoholics with higher dietary protein and fat intake than those who consume less protein and fat.
G. Postoperative (Iatrogenic) Pancreatitis
Most cases of postoperative pancreatitis follow common bile duct exploration, especially if sphincterotomy was performed. Two practices, now largely abandoned, were often responsible: (1) use of a common duct T tube with a long arm passing through the sphincter of Oddi and (2) dilation of the sphincter to 5-7 mm during common duct exploration. Operations on the pancreas, including pancreatic biopsy, are another cause. A few cases follow gastric surgery or even operations remote from the pancreas. Pancreatitis is particularly common after cardiac surgery with cardiopulmonary bypass, where the risk factors are preoperative renal failure, valve surgery, postoperative hypotension, and (particularly) the perioperative administration of calcium chloride (> 800 mg calcium chloride per square meter of body surface area). Pancreatitis may also complicate endoscopic retrograde pancreatography or endoscopic sphincterotomy.
Rarely, pancreatitis follows Billroth II gastrectomy, owing to acute obstruction of the afferent loop and reflux of duodenal secretions under high pressure into the pancreatic ducts. The condition has been recreated experimentally in dogs (Pfeffer loop preparation).
H. Drug-Induced Pancreatitis
Drugs are probably responsible for more cases of acute pancreatitis than is generally suspected. The most commonly incriminated drugs are corticosteroids, estrogen-containing contraceptives, azathioprine, thiazide diuretics, and tetracyclines. Pancreatitis associated with use of estrogens is usually the result of drug-induced hypertriglyceridemia. The mechanisms involved in the case of other drugs are unknown.
I. Obstructive Pancreatitis
Chronic partial obstruction of the pancreatic duct may be congenital or may follow healing after injury or inflammation. Over time, the parenchyma drained by the obstructed duct is replaced by fibrous tissue, and chronic pancreatitis develops. Sometimes there are episodes of acute pancreatitis as well.
Pancreas divisum may predispose to a kind of obstructive pancreatitis. If this anomaly is present and further narrowing of the opening of the minor papilla occurs (eg, by an inflammatory process), the orifice may be inadequate to handle the flow of pancreatic juice. The diagnosis of pancreas divisum may be made by endoscopic retrograde cholangio-pancreatography (ERCP). If a patient with the anomaly is found to have documented episodes of acute pancreatitis and no other cause is found, it is reasonable to assume that the anomaly is the cause.
Surgical sphincteroplasty of the minor papilla or the insertion of a stent has been proposed as treatment, but results have been suboptimal. This may be due to the presence of irreversible parenchymal changes and the persistence of chronic inflammation. In patients with obvious changes of chronic pancreatitis, surgical treatment should consist of pancreatic resection or drainage.
J. Idiopathic Pancreatitis and Miscellaneous Causes
In about 15% of patients, representing the third largest group after biliary and alcoholic pancreatitis, there is no identifiable cause of the condition. If investigated in greater than usual detail (eg, duodenal drainage examination for cholesterol crystals), many of these patients will be found to have gallstones or biliary sludge undetectable by ultrasound scans. Recent data have linked mutations of the cystic fibrosis gene to idiopathic pancreatitis.
Viral infections and scorpion stings may cause pancreatitis.
The concept that pancreatitis is due to enzymatic digestion of the gland is supported by the finding of proteolytic enzymes in ascitic fluid and increased amounts of phospholipase A and lysolecithins in pancreatic tissue from patients with acute pancreatitis. Experimentally, pancreatitis can be created readily if activated enzymes are injected into the pancreatic ducts under pressure. Trypsin has not been found in excessive amounts in pancreatic tissue from affected humans, possibly because of inactivation by trypsin inhibitors. Nevertheless, although the available evidence is inconclusive, the autodigestion theory is almost universally accepted. Other proposed factors are vascular insufficiency, lymphatic congestion, and activation of the kallikrein-kinin system.
For many years, trypsin and other proteases were held to be the principal injurious agents, but recent evidence has emphasized phospholipase A, lipase, and elastase as perhaps of greater importance. Trypsin ordinarily does not attack living cells, and even when trypsin is forced into the interstitial spaces, the resulting pancreatitis does not include coagulation necrosis, which is so prominent in human pancreatitis.
Phospholipase A, in the presence of small amounts of bile salts, attacks free phospholipids (eg, lecithin) and those bound in cellular membranes to produce extremely potent lyso-compounds. Lysolecithin, which would result from the action of phospholipase A on biliary lecithin, or phospholipase A itself, plus bile salts, is capable of producing severe necrotizing pancreatitis. Trypsin is important in this scheme, because small amounts are needed to activate phospholipase A from its inactive precursor.
Elastase, which is both elastolytic and proteolytic, is secreted in an inactive form. Because it can digest the walls of blood vessels, elastase has been thought to be important in the pathogenesis of hemorrhagic pancreatitis.
If autodigestion is the final common pathway in pancreatitis, earlier steps must account for the presence of active enzymes and their reaction products in the ducts and their escape into the interstitium. The following are the most popular theories that attempt to link the known etiologic factors with autodigestion.
In animals, ligation of the pancreatic duct generally produces mild edema of the pancreas that resolves within a week. Thereafter, atrophy of the secretory apparatus occurs. On the other hand, partial or intermittent ductal obstruction, which more closely mimics what seems to happen in humans, can produce frank pancreatitis if the gland is simultaneously stimulated to secrete. The major shortcoming of these experiments has been the difficulty encountered in attempting to cause severe pancreatitis in this way. However, since the human pancreas manufactures ten times as much phospholipase A as does the dog or rat pancreas, the consequences of obstruction in humans conceivably could be more serious.
Flow between the biliary and pancreatic ducts requires a common channel connecting these two systems with the duodenum. Although these ducts converge in 90% of humans, only 10% have a common channel long enough to permit biliary-pancreatic reflux if the ampulla contained a gallstone. Experimentally, pancreatitis produced by pancreatic duct obstruction alone is similar in severity to pancreatitis following obstruction of a common channel, so biliary reflux is discounted as an etiologic factor in this disease.
The above theories do not explain activation of pancreatic enzymes, a process that normally takes place through the action of enterokinase in the duodenum. In experimental animals, if the segment of duodenum into which the pancreatic duct empties is surgically converted to a closed loop, reflux of duodenal juice initiates severe pancreatitis (Pfeffer loop). Pancreatitis associated with acute afferent loop obstruction after Billroth II gastrectomy is probably the result of similar factors. Other than in this specific example, there is no direct evidence for duodenal reflux in the pathogenesis of pancreatitis in humans.
D. Back Diffusion Across the Pancreatic Duct
Just as the gastric mucosa must serve as a barrier to maintain high concentrations of acid, so must the epithelium of the pancreatic duct prevent diffusion of luminal enzymes into the pancreatic parenchyma. Experiments in cats have shown that the barrier function of the pancreatic duct is vulnerable to several injurious agents, including alcohol and bile acids. Furthermore, the effects of alcohol can occur even after oral ingestion, because alcohol is secreted in the pancreatic juice. Injury to the barrier renders the duct permeable to molecules as large as MW 20,000, and enzymes from the lumen may be able to enter the gland and produce pancreatitis.
Some studies have shown that a very early event in several forms of experimental pancreatitis, including that due to pancreatic duct obstruction, consists of zymogen activation within acinar cells by lysosomal hydrolases (eg, cathepsin B). This may represent the long-sought unifying explanation. Other factors must be postulated, however, to account for the variations in severity of the disease. In biliary pancreatitis, transient obstruction of the ampulla of Vater by a gallstone is most likely the first event. Alcoholic pancreatitis probably has several causes, including partial ductal obstruction, secretory stimulation, acute effects on the ductal barrier, and toxic actions of alcohol on parenchymal cells.
E. Systemic Manifestations
Severe acute pancreatitis may be complicated by multiple organ failure, principally respiratory insufficiency (acute respiratory distress syndrome), myocardial depression, renal insufficiency, and gastric stress ulceration. The pathogenesis of these complications is similar in many respects to that of multiple organ failure in sepsis, and in fact, sepsis due to pancreatic abscess formation is a contributing factor in some of the most severe cases of acute pancreatitis. During acute pancreatitis, pancreatic proteases, bacterial endotoxins, and other active agents are liberated into the systemic circulation. The endotoxin probably originates from bacteria that translocate through an abnormally permeable intestinal mucosa. Within the circulation, the proteases and the endotoxin activate the complement system (especially C5) and kinins. Complement activation leads to granulocyte aggregation and accumulation of aggregates in the pulmonary capillaries. The granulocytes release neutrophil elastase, superoxide anion, hydrogen peroxide, and hydroxide radicals, which in concert with bradykinin exert local toxic effects on the pulmonary epithelium that result in increased permeability. Arachidonate metabolites (eg, PGE2, PGI2, leukotriene B4) may also be involved in some way. Analogous events are thought to occur in other organs.
et al.. Hereditary pancreatitis: endoscopic and surgical management. J Gastrointest Surg 2013;17(5):847–856.
MJ Epidemiology, aetiology and outcome of acute and chronic pancreatitis: an update. Best Pract Res Clin Gastroenterol 2008;22(1):45–63.
Working Group IAP/APA Acute Pancreatitis Guidelines. IAP/APA evidence-based guidelines for the management of acute pancreatitis. Pancreatology 2013;13(4 suppl 2):e1–e15.
ESSENTIALS OF DIAGNOSIS
Abrupt onset of epigastric pain, frequently with back pain
Nausea and vomiting
Elevated serum or urinary amylase
Cholelithiasis or alcoholism (many patients)
While edematous and hemorrhagic pancreatitis are manifestations of the same pathologic processes and the general principles of treatment are the same, hemorrhagic pancreatitis has more complications and a higher death rate. In edematous pancreatitis, the glandular tissue and surrounding retroperitoneal structures are engorged with interstitial fluid, and the pancreas is infiltrated with inflammatory cells that surround small foci of parenchymal necrosis. Hemorrhagic pancreatitis is characterized by bleeding into the parenchyma and surrounding retroperitoneal structures and extensive pancreatic necrosis. In both forms, the peritoneal surfaces may be studded with small calcifications representing areas of fat necrosis.
The acute attack frequently begins with severe epigastric pain that radiates through to the back. The pain is unrelenting and usually associated with vomiting and retching. In severe cases, the patient may collapse from shock.
Depending on the severity of the disease, there may be profound dehydration, tachycardia, and postural hypotension. Myocardial function is depressed in severe pancreatitis, presumably because of circulating factors that affect cardiac performance. Examination of the abdomen reveals decreased or absent bowel sounds and tenderness that may be generalized but more often is localized to the epigastrium. Temperature is usually normal or slightly elevated in uncomplicated pancreatitis. Clinical evidence of pleural effusion may be present, especially on the left. If an abdominal mass is found, it probably represents a swollen pancreas (phlegmon) or, later in the illness, a pseudocyst or abscess. In 1%-2% of patients, bluish discoloration is present in the flank (Grey Turner sign) or periumbilical area (Cullen sign), indicating hemorrhagic pancreatitis with dissection of blood retroperitoneally into these areas.
The hematocrit may be elevated as a consequence of dehydration or low as a result of abdominal blood loss in hemorrhagic pancreatitis. There is usually a moderate leukocytosis, but total white blood cell counts over 12,000/mL are unusual in the absence of suppurative complications. Liver function studies are usually normal, but there may be a mild elevation of the serum bilirubin concentration (usually < 2 mg/dL).
The serum amylase concentration rises to more than three times normal within 6 hours after the onset of an acute episode and generally remains elevated for several days. Values in excess of 1000 IU/dL occur early in the attack in 95% of patients with biliary pancreatitis and 85% of patients with acute alcoholic pancreatitis. Those with the most severe disease are more apt to have amylase levels below 1000 IU/dL.
Elevated serum lipase is detectable early and for several days after the acute attack. Since the lipase level tends to be higher in alcoholic pancreatitis and the amylase level higher in gallstone pancreatitis, the lipase/amylase ratio has been suggested as a means to help distinguishing the two.
Elevated amylase levels may occur in other acute abdominal conditions, such as gangrenous cholecystitis, small bowel obstruction, mesenteric infarction, and perforated ulcer, though levels rarely exceed 500 IU/dL. Episodes of acute pancreatitis may occur without rises in serum amylase; this is the rule if hyperlipidemia is present. Furthermore, high levels may return to normal before blood is drawn.
The methods most commonly used for measuring amylase in the serum detect pancreatic amylase, salivary amylase, and macroamylase. However, hyperamylasemia is sometimes present in patients with abdominal pain when the elevated amylase levels consist entirely of salivary amylase or macroamylase and the pancreas is not inflamed.
In severe pancreatitis, the serum calcium concentration may fall as a result of calcium being complexed with fatty acids (liberated from retroperitoneal fat by lipase) and impaired reabsorption from bone owing to the action of calcitonin (liberated by high levels of glucagon). Relative hypoparathyroidism and hypoalbuminemia have also been implicated.
In about two-thirds of cases, a plain abdominal film is abnormal. The most frequent finding is isolated dilation of a segment of gut (sentinel loop) consisting of jejunum, transverse colon, or duodenum adjacent to the pancreas. Gas distending the right colon that abruptly stops in the mid or left transverse colon (colon cutoff sign) is due to colonic spasm adjacent to the pancreatic inflammation. Both of these findings are relatively nonspecific. Glandular calcification may be evident, signifying chronic pancreatitis. An upper gastrointestinal series may show a widened duodenal loop, swollen ampulla of Vater, and, occasionally, evidence of gastric irritability. Chest films may reveal pleural effusion on the left side. Occasionally, radiopaque gallstones will be apparent on plain x-rays.
Ultrasound study may demonstrate gallstones early in the attack and may be used as a baseline for sequential examinations of the pancreas.
A CT scan of the pancreas using intravenous contrast media should be obtained for one of three reasons: (1) diagnostic uncertainty, (2) confirmation/evaluation of severity based upon other markers or clinical suspicion, or (3) evaluation in the setting of clinical deterioration or failure to respond to therapy. The radiologic findings may be consistent with any of the following: relatively normal appearing pancreas, pancreatic phlegmon, pancreatic phlegmon with extension of the inflammatory process to adjacent extrapancreatic spaces, pancreatic necrosis, or pancreatic pseudocyst, or abscess formation.
Several weeks after the pancreatitis has subsided, ERCP may be of value in patients with a tentative diagnosis of idiopathic pancreatitis (ie, those who have no history of alcoholism and no evidence of gallstones on ultrasound and oral cholecystogram). This examination demonstrates gallstones or changes of chronic pancreatitis in about 40% of such patients.
To some extent, acute pancreatitis is a diagnosis of exclusion, for other acute upper abdominal conditions such as acute cholecystitis, penetrating or perforated duodenal ulcer, high small bowel obstruction, acute appendicitis, and mesenteric infarction must always be seriously considered. In most cases, the distinction is possible on the basis of the clinical picture, laboratory findings, and CT scans. The critical point is that the diseases with which acute pancreatitis is most likely to be confused are often lethal if not treated surgically.
Chronic hyperamylasemia occurs rarely without any relation to pancreatic disease. Some cases are associated with renal failure, chronic sialadenitis, salivary tumors, ovarian tumors, or liver disease, but often there is no explanation. Analysis of serum amylase isoenzymes is the only way to determine whether the amylase originates from salivary glands or pancreas. Macroamylasemia is a chronic hyperamylasemia in which normal amylase (usually salivary) is bound to a large serum glycoprotein or immunoglobulin molecule and is therefore not excreted into urine. The diagnosis rests on the combination of hyperamylasemia and low urinary amylase. Macroamylasemia has been found in patients with other diseases such as malabsorption, alcoholism, and cancer. Many patients have abdominal pain, but the relationship of the pain and the macroamylasemia is uncertain.
The principal complications of acute pancreatitis are abscess and pseudocyst formation. These are discussed in separate sections. Gastrointestinal bleeding may occur from adjacent inflamed stomach or duodenum, ruptured pseudocyst, or peptic ulcer. Intraperitoneal bleeding may occur spontaneously from the celiac or splenic artery or from the spleen following acute splenic vein thrombosis. Involvement of the transverse colon or duodenum by the inflammatory process may result in partial obstruction, hemorrhage, necrosis, or fistula formation.
Early identification of patients at greatest risk of complications allows them to be managed more aggressively, which appears to decrease the mortality rate. The criteria of severity that have been found to be reliable are based either on the systemic manifestations of the disease as reflected in the clinical and laboratory findings or on the local changes in the pancreas as reflected by the findings on CT scan. Ranson used the former approach to develop the staging criteria listed in Table 26–1. Just the single finding of fluid sequestration (ie, fluid administered minus urine output) exceeding 2 L/d for more than 2 days is a reasonably accurate dividing line between severe (life-threatening) and mild-to-moderate disease. The local changes in the pancreas as shown on CT scans may be even more revealing. The presence of any of the following indicates a high risk of local infection in the pancreatic bed: involvement of extrapancreatic spaces in the inflammatory process, pancreatic necrosis (areas in the pancreas that do not enhance with intravenous contrast media), and early signs of abscess formation (eg, gas bubbles in the tissue).
Table 26–1.Ranson criteria of severity of acute pancreatitis.1 ||Download (.pdf) Table 26–1. Ranson criteria of severity of acute pancreatitis.1
Criteria Present Initially
Age > 55 years
White blood cell count > 16,000/μL
Blood glucose > 200 mg/dL
SERUM LDH > 350 IU/L
AST (SGOT) > 250 IU/dL
Criteria Developing During First 24 Hours
Hematocrit fall > 10%
BUN rise > 8 mg/dL
Serum Ca2+ < 8 mg/dL
Arterial PO2 < 60 mm Hg
Base deficit > 4 meq/L
Estimated fluid sequestration > 600 mL
The goals of medical therapy are reduction of pancreatic secretory stimuli and correction of fluid and electrolyte derangements.
Oral intake is withheld. A nasogastric tube is often inserted to aspirate gastric secretions, although the latter has no specific therapeutic effect. Oral feeding should be resumed only after the patient appears much improved, appetite has returned, and serum amylase levels have dropped to normal. Premature resumption of eating may result in exacerbation of disease.
Patients with acute pancreatitis sequester fluid in the retroperitoneum and bowel, and large volumes of intravenous fluids are necessary to maintain circulating blood volume and renal function. In severe hemorrhagic pancreatitis, blood transfusions may also be required. The adequacy of fluid replacement is the single most important aspect of medical therapy. In fact, undertreatment with fluids may actually contribute to the progression of pancreatitis. Fluid replacement may be judged most accurately by monitoring the volume and concentration of the urine.
Antibiotics are not useful in mild cases of acute pancreatitis. However, some studies have shown benefit of antibiotics that penetrate pancreatic tissue for patients with severe pancreatitis. Imipenem is the most commonly used antibiotic, though its use is not universally supported even in patients with severe disease. Antibiotics should also be used for treatment of specific operative complications.
In severe attacks of acute pancreatitis, hypocalcemia may require parenteral calcium replacement in amounts determined by serial calcium measurements. Recognition of hypocalcemia is important because it may produce cardiac dysrhythmias. Hypomagnesemia is also common, especially in alcoholics, and magnesium should also be replaced as indicated by serum levels.
Hypoxemia severe enough to require therapy develops in about 30% of patients with acute pancreatitis. It is often insidious, without clinical or x-ray signs, and out of proportion to the severity of the pancreatitis. The most pronounced examples accompany severe pancreatitis, often in association with hypocalcemia. The basic lesion, a form of adult respiratory distress syndrome, is poorly understood. Pulmonary changes include decreased vital capacity and an oxygen diffusion defect.
Hypoxemia must be suspected in every patient, and oxygen saturation should be monitored periodically or continuously for the first few hospital days. An occasional patient requires endotracheal intubation and mechanical ventilation. Diuretics may be useful in decreasing lung water and improving arterial oxygen saturation.
Enteral feeding should be used to support nutritional goals during the acute episode. Total parenteral nutrition avoids pancreatic stimulation and should be used for nutritional support only if enteral feeding is not practical for 5 or more days. Neither form of nutrition directly affects recovery of the pancreas.
Octreotide, H2 receptor blockers, anticholinergic drugs, glucagon, and aprotinin have shown no beneficial effects in controlled trials.
B. Endoscopic Sphincterotomy
Biliary pancreatitis is caused by a gallstone becoming lodged in the ampulla of Vater. In most cases, the stone passes into the intestine but occasionally it becomes impacted in the ampulla, which results in more severe disease. Less than 10% of cases of biliary pancreatitis are severe (ie, three or more Ranson criteria), but in severe cases, endoscopic sphincterotomy performed within 72 hours of the onset of the disease has been shown to decrease the incidence of concomitant biliary sepsis and lower the mortality rate from the pancreatitis.
Surgery is generally contraindicated in uncomplicated acute pancreatitis. However, when the diagnosis is uncertain in a patient with severe abdominal pain, diagnostic laparoscopy or laparotomy is not thought to aggravate pancreatitis.
When operative evaluation has been performed for diagnosis and mild to moderate pancreatitis is found, cholecystectomy should be performed if gallstones are present, but the pancreas should be left undisturbed. Although some surgeons place drains and irrigating catheters in the region of the pancreas, we prefer to keep foreign bodies out of this area.
The diagnosis of biliary pancreatitis can usually be suspected on the basis of ultrasound studies of the gallbladder early in the acute attack. Cholecystectomy should be performed on these patients during hospitalization for the acute attack soon after the attack resolves. A longer delay (even a few weeks) is associated with a high incidence (80%) of recurrent pancreatitis. Since life-threatening attacks are uncommon in gallstone pancreatitis, operation or endoscopic therapy early in an attack is rarely justified. However, when the attack is especially severe, elective cholecystectomy should be deferred up to several months to allow complete recovery from pancreatitis.
It is currently thought that debridement of dead peripancreatic tissue, which is often (40% of cases) colonized by bacteria, reduces the mortality rate of acute severe necrotizing pancreatitis. Historical controls place the mortality rate at 50%-80% in the absence of operative treatment and 10%-40% among patients subjected to necrosectomy. The diagnosis of necrotizing pancreatitis is suspected from the clinical findings; patients treated surgically have three or more Ranson criteria and average about 4½ criteria. Contrast-enhanced CT scans obtained early in the course of the disease are studied for the presence of nonenhancing areas, which indicate lack of vascular perfusion and reflect the presence of necrotic peripancreatic fat or pancreatic parenchyma. Percutaneous needle aspiration of these areas is used to detect the presence of bacterial colonization. A distinction is made between these cases of “infected necrotizing pancreatitis” and “pancreatic abscess,” which may appear later in the course of the disease. Patients with infected necrotizing pancreatitis and severe clinical findings benefit most from surgical therapy, but laparotomy may be undertaken just because of a deteriorating condition in patients with necrotizing pancreatitis in the absence of bacterial colonization. At surgery, all peripancreatic spaces are opened and any necrotic tissue is removed by gentle blunt dissection. This can be accomplished with less invasive videoscopic techniques. Other than CT evidence of necrotic tissue with or without infection, there are presently no other criteria in general use that call for pancreatic surgery in patients with severe pancreatitis.
Surgery for complications of acute pancreatitis, such as abscess, pseudocyst, and pancreatic ascites, is discussed below.
The death rate associated with acute pancreatitis is about 10%, and nearly all deaths occur in a first attack and among patients with three or more Ranson criteria of severity. Respiratory insufficiency and hypocalcemia indicate a poor prognosis. The death rate associated with severe necrotizing pancreatitis is 50% or more, but surgical therapy lowers the figure to about 20%. Persistent fever or hyperamylasemia 3 weeks or longer after an attack of pancreatitis usually indicates the presence of a pancreatic abscess or pseudocyst.
et al.. International Multidisciplinary Panel of Speakers and Moderators. Interventions for necrotizing pancreatitis: summary of a multidisciplinary consensus conference. Pancreas 2012;41(8):1176–1194.
et al.. Dutch Pancreatitis Study Group. A step-up approach or open necrosectomy for necrotizing pancreatitis. N Engl J Med 2010;362(16):1491–1502.
Working Group IAP/APA Acute Pancreatitis Guidelines. IAP/APA evidence-based guidelines for the management of acute pancreatitis. Pancreatology 2013:13(4 suppl 2):e1–e15.
ESSENTIALS OF DIAGNOSIS
Epigastric mass and pain
Mild fever and leukocytosis
Persistent serum amylase elevation
Pancreatic cyst demonstrated by ultrasound or CT scan
Pancreatic pseudocysts are encapsulated collections of fluid with high enzyme concentrations that arise from the pancreas. They are usually located either within or adjacent to the pancreas in the lesser sac. The walls of a pseudocyst are formed by inflammatory fibrosis of the peritoneal, mesenteric, and serosal membranes, which limits spread of the pancreatic juice as the lesion develops. The term pseudocyst denotes absence of an epithelial lining, whereas true cysts are lined by epithelium.
Two different processes are involved in the pathogenesis of pancreatic pseudocysts. Many occur as complications of severe acute pancreatitis, where extravasation of pancreatic juice and glandular necrosis form a sterile pocket of fluid that is not reabsorbed as inflammation subsides. Superinfection of such collections leads to pancreatic abscess instead of pseudocyst. In other patients, usually alcoholics or trauma victims, pseudocysts appear without preceding acute pancreatitis. The mechanism in these cases consists of ductal obstruction and formation of a retention cyst that loses its epithelial lining as it grows beyond the confines of the gland. In posttraumatic pseudocyst, symptoms usually do not appear until several weeks after the injury. Some are iatrogenic, eg, occurring during splenectomy; others follow an external blow to the abdomen.
Pseudocysts develop in about 2% of cases of acute pancreatitis. The cysts are single in 85% of cases and multiple in the remainder.
A pseudocyst should be suspected when a patient with acute pancreatitis fails to recover after a week of treatment or when, after improving for a time, symptoms return. Since it is now fairly routine to obtain a CT scan early in an attack of severe acute pancreatitis, the early stages of pseudocyst formation are often demonstrated radiographically before specific clinical findings appear. The first clinical manifestation is usually a palpable tender mass in the epigastrium, consisting of a swollen pancreas and contiguous viscera (a phlegmon). With time, the mass may subside, but if it persists it most likely represents a pseudocyst.
In other cases, the pseudocyst develops insidiously without an obvious attack of acute pancreatitis.
Regardless of the type of prodromal phase, pain is the most common finding. Fever, weight loss, tenderness, and a palpable mass are present in about half of patients. A few have jaundice, a manifestation of obstruction of the intrapancreatic segment of the bile duct.
An elevated serum amylase and leukocytosis are present in about half of patients. When present, elevated bilirubin levels reflect biliary obstruction. Of those patients with acute pancreatitis whose serum amylase remains elevated for as long as 3 weeks, about half will have a pseudocyst.
CT scan (Figure 26–3) is the diagnostic study of choice. The size and shape of the cyst and its relationship to other viscera can be seen. Acute pseudocysts are often irregular in shape; chronic pseudocysts are most often circular or nearly so. An enlarged pancreatic duct may be demonstrated in patients with chronic pancreatitis. A dilated common bile duct would suggest biliary obstruction, either from the cyst or from underlying chronic pancreatitis.
CT scan of a large pancreatic pseudocyst impinging on the posterior wall of the stomach. The large arrow indicates the pseudocyst; the smaller area indicates the stomach. A: More cephalad in the abdomen, the pseudocyst abuts the stomach and liver. B: More caudad in the abdomen, the pseudocyst is immediately posterior to the gastric antrum. The stomach is compressed against the anterior wall of the abdomen, and the duodenum is stretched over the pseudocyst, causing early satiety. A cyst in this location is usually best drained into the stomach.
The gallbladder should be studied by ultrasound to look for stones, especially in patients with acute pancreatitis. Although ultrasound can also demonstrate pseudocysts, the amount of important detail obtained is limited compared to CT scan, and consequently the role of ultrasound is mainly to follow changes in size of an acute pseudocyst already imaged by CT scan, so the amount of x-ray exposure can be minimized.
MRCP and/or ERCP should be performed if there is concern about significant abnormalities of the bile or pancreatic duct as suggested by CT scans or the results of liver function tests. Either duct may be dilated and in need of surgical drainage in conjunction with drainage of the pseudocyst. ERCP usually opacifies the pseudocyst as well, but the information is not usually of major value in planning treatment, so ERCP is not obtained routinely.
An upper gastrointestinal series will often reveal a mass in the lesser sac that distorts the stomach or duodenum, but this is not particularly useful information. The principal indication for an upper gastrointestinal series is to search for a site of gastric or duodenal obstruction in patients who are vomiting.
With wide use of sensitive imaging studies in the diagnosis of pancreatic disease, small asymptomatic pseudocysts are often demonstrated. The natural history of these subclinical lesions is benign, and there is no indication for prophylactic surgical treatment.
Pancreatic pseudocysts must be distinguished from pancreatic abscess and acute pancreatic phlegmon. Patients with an abscess exhibit signs of infection.
Rarely, patients with pseudocyst present with weight loss, jaundice, and a nontender palpable gallbladder and are first thought to have pancreatic carcinoma. CT scans show that the lesion is fluid-filled, which suggests the correct diagnosis.
Neoplastic cysts—either cystadenoma or cystadenocarcinoma—account for about 5% of all cases of cystic pancreatic masses and may be indistinguishable preoperatively from pseudocyst. The correct diagnosis can be made from the gross appearance supplemented by a biopsy obtained at operation.
Infection is a rare complication resulting in high fever, chills, and leukocytosis. Drainage is required as soon as the diagnosis is suspected. Some lesions can be drained externally via a catheter placed percutaneously using ultrasound guidance. Internal drainage of infected pseudocysts adherent to the stomach can be achieved surgically by cystogastrostomy; otherwise, drainage should be external, because the suture line of a Roux-en-Y cystojejunostomy may not heal.
Sudden perforation into the free peritoneal cavity produces severe chemical peritonitis, with abdominal rigidity and severe pain. Rapid enlargement of the pseudocyst is sometimes noted before it ruptures. The treatment is emergency surgery with irrigation of the peritoneal cavity and a drainage procedure for the pseudocyst. The wall of a ruptured pseudocyst is usually too flimsy to hold sutures securely, so most ruptured cysts must be drained externally. Rupture of a pseudocyst occurs in less than 5% of cases, and even with prompt treatment it may be fatal.
Bleeding may occur into the cyst cavity or an adjacent viscus into which the cyst has eroded. Intracystic bleeding may present as an enlarging abdominal mass with anemia resulting from blood loss. If the cyst has eroded into the stomach, there may be hematemesis, melena, and blood in the nasogastric aspirate. The rapidity of the blood loss often produces hemorrhagic shock, which may preclude arteriography. If time permits, however, emergency arteriography should be performed to delineate the site of bleeding, which is usually a false aneurysm of an artery in the cyst wall, and to embolize it if possible. If embolization successfully occludes the bleeding vessel, several weeks should elapse to ensure that bleeding will not recur, and at that point the pseudocyst should be drained surgically in the same fashion as a nonbleeding pseudocyst. If the bleeding cannot be stopped by embolization, emergency surgery should be performed. Usually all that can be done is to open the cyst and suture ligate the bleeding vessel in the cyst wall, followed by external or internal drainage of the cyst. Sometimes it is possible to excise the cyst, which is desirable because doing so more certainly avoids the risk of recurrent hemorrhage.
The principal indications for treating pancreatic pseudocysts are to improve symptoms and to prevent complications. Recent data indicate that the natural history of these lesions is more benign than previously thought—that in the absence of symptoms or radiographic evidence of enlargement (and irrespective of cyst size), expectant management is not unreasonable, and that a few untreated cysts resolve spontaneously even after being stable for months. Expectant management is especially important in the first 6-12 weeks of existence of cysts that have arisen during an attack of acute pancreatitis. The chances of spontaneous resolution are about 40%; catheter drainage at this stage is meddlesome; and internal drainage of the cyst by surgery may be difficult or even impossible. Thereafter, for cysts greater than 5 cm, treatment is usually recommended over expectant management (in the absence of contraindications, such as serious concomitant disease), because most cysts can be promptly eliminated by percutaneous catheter drainage or surgical drainage into the stomach or intestine. This obviates the need for prolonged follow-up with repeated ultrasound or CT scans and avoids the risks, albeit low, of complications. Patients who present with a symptomatic pseudocyst and no history of recent acute pancreatitis may be treated without the 6- to 12-week delay, because their cyst wall is tough (mature) enough to hold sutures and allow an anastomosis with the gut. Jaundice in a patient with a pseudocyst is usually caused by pressure from the cyst on the bile duct. Draining the pseudocyst usually relieves the obstruction, but an operative cholangiogram should be obtained to make sure.
Excision is the most definitive treatment but is usually confined to chronic pseudocysts in the tail of the gland. This approach is recommended especially for cysts that follow trauma, where the head and body of the gland are normal. Most cysts should be drained either externally or internally into the gut.
External drainage is best for critically ill patients or when the cyst wall has not matured sufficiently for anastomosis to other organs. A large tube is sewn into the cyst lumen, and its end is brought out through the abdominal wall. External drainage is complicated in a third of patients by a pancreatic fistula that sometimes requires surgical drainage but on the average closes spontaneously in several months. The incidence of recurrent pseudocyst is about four times greater after external drainage than after drainage into the gut.
The preferred method of treatment is internal drainage, where the cyst is anastomosed to a Roux-en-Y limb of jejunum (cystojejunostomy), to the posterior wall of the stomach (cystogastrostomy), or to the duodenum (cystoduodenostomy). The interior of the cyst should be inspected for evidence of a tumor and biopsy performed as appropriate. Cystogastrostomy is preferable for cysts behind and densely adherent to the stomach. This may well be done laparoscopically in the future. To accomplish free, dependent drainage, Roux-en-Y cystojejunostomy provides better drainage of cysts in various other locations. Cystoduodenostomy is indicated for cysts deep within the head of the gland and adjacent to the medial wall of the duodenum—lesions that would be difficult to drain by any other technique. The procedure consists of making a lateral duodenotomy, opening into the cyst through the medial wall of the duodenum, and then closing the lateral duodenotomy. Following internal drainage, the cyst cavity becomes obliterated within a few weeks. Even after cystogastrostomy, an unrestricted diet can be allowed within a week after surgery, and x-rays taken at this time usually show only a small residual cyst cavity.
External drainage can be established by a percutaneous catheter placed into the cyst under radiographic or ultrasound control. This is the preferred method for infected pseudocysts. In some centers, it is also used for the majority of uncomplicated pseudocysts as the primary mode of therapy. About two-thirds of cysts so treated are permanently eradicated. It may also be useful to shrink a truly huge pseudocyst (eg, one that occupies half of the abdominal cavity), because it is technically difficult to obtain adequate internal drainage of these lesions into the gut. Occasionally, a sterile cyst may become infected when a narrow catheter is inserted into it. This is more likely when the cyst lumen contains debris that is not drained effectively by this technique. Chronic external pancreatic fistula is a potential complication of this method.
Two other drainage techniques have been tried: (1) passing a catheter percutaneously through the anterior abdominal wall, the anterior wall of the stomach, and through the posterior stomach into the cyst. After several weeks, the catheter is removed, and a chronic tract remains from cyst to gastric lumen. (2) Using a fiberoptic gastroscope to make a small incision through the back wall of the stomach into the cyst.
The recurrence rate for pancreatic pseudocyst is about 10%, and recurrence is more frequent after treatment by external drainage. Serious postoperative hemorrhage from the cyst occurs rarely—most often after cystogastrostomy. In most cases, however, surgical treatment of pseudocysts is uncomplicated and definitively solves the immediate problem. Many patients later experience chronic pain as a manifestation of underlying chronic pancreatitis.
AR Operative management of acute pancreatitis. Surg Clin North Am 2013;93(3):595–610.
et al.. Failure to comply with NCCN guidelines for the management of pancreatic cancer compromises outcomes. HPB (Oxford) 2012;14(8):539–547.
Pancreatic abscess, which complicates about 5% of cases of acute pancreatitis, is invariably fatal if it is not treated surgically. It tends to develop in severe cases accompanied by hypovolemic shock and pancreatic necrosis and is an especially frequent complication of postoperative pancreatitis. Abscess formation follows secondary bacterial contamination of necrotic pancreatic debris and hemorrhagic exudate. The organisms may spread to the pancreas hematogenously as well as directly through the wall of the transverse colon. It is unknown whether prophylactic antibiotics given early in the course of severe acute pancreatitis decrease the incidence of abscess.
An abscess should be suspected when a patient with severe acute pancreatitis fails to improve and develops rising fever or when symptoms return after a period of recovery. In most cases, there is improvement for a while before signs of infection appear 2-4 weeks after the attack began. Epigastric pain and tenderness and a palpable tender mass are clues to diagnosis. In many cases, the findings are not especially striking—ie, the temperature is only modestly elevated and the patient does not appear septic. Vomiting or jaundice may be present, but in some cases fever and leukocytosis are the only findings. The serum amylase may be elevated but usually is normal. Characteristically, the serum albumin is below 2.5 g/dL and the alkaline phosphatase is elevated. Pleural fluid and diaphragmatic paralysis may be evident on chest x-rays. An upper gastrointestinal series may show deformity of the stomach or duodenum by a mass, but it usually does not, and the changes are nonspecific in any case. Diagnostic CT scans will usually indicate the presence of a fluid collection in the area of the pancreas. Gas in the collection on plain films or CT scans is virtually diagnostic. Percutaneous CT scan-guided aspiration may be used to aid in diagnosis and obtain a specimen for Gram stain and culture.
In general, the diagnosis is difficult, treatment is often instituted late, illness is severe, and death rates are high.
The infected collection must be drained. Percutaneous catheter drainage may be helpful as a first step in order to decrease toxicity or to obtain a specimen for culture. In some cases, catheter drainage will prove to be definitive, but most often the infected retroperitoneal space is honeycombed and contains necrotic debris that cannot pass through the catheter, so surgical debridement is necessary. It is best to consider catheter drainage as a preparatory step for surgery rather than a curative treatment, for that is the usual relationship. Otherwise, there may be a tendency to delay surgery for too long as futile efforts are repeatedly made to manipulate the catheters into better positions. In fact, the two measures—surgical debridement and catheter drainage—are complementary.
Preoperatively, the patient should be given broad-spectrum antibiotics, since the organisms are usually a mixed flora, most often Escherichia coli, Bacteroides, Staphylococcus, Klebsiella, Proteus, Candida albicans, etc. Necrotic debris should be removed and external drainage instituted.
Postoperative hemorrhage (immediate or delayed) from the abscess cavity occurs occasionally.
The death rate is about 20%, a consequence of the severity of the condition, incomplete surgical drainage, and the inability in some cases to make the diagnosis.
AR Operative management of acute pancreatitis. Surg Clin North Am 2013;93(3):595–610.
4. Pancreatic Ascites & Pancreatic Pleural Effusion
Pancreatic ascites consists of accumulated pancreatic fluid in the abdomen without peritonitis or severe pain. Since many of these patients are alcoholic, they are often thought at first to have cirrhotic ascites. The syndrome is most often due to chronic leakage of a pseudocyst, but a few cases are due to disruption of a pancreatic duct. The principal causative factors are alcoholic pancreatitis in adults and traumatic pancreatitis in children. Marked recent weight loss is a major clinical manifestation, and unresponsiveness of the ascites to diuretics is an additional diagnostic clue. The ascitic fluid, which ranges in appearance from straw-colored to blood-tinged, contains elevated protein (> 2.9 g/dL) and amylase levels. Once this condition is suspected, definitive diagnosis is based on chemical analysis of the ascitic fluid and endoscopic retrograde pancreatography. The latter procedure frequently demonstrates the point of fluid leak and allows a rational surgical approach if operation is required.
Initial therapy should consist of a period of intravenous hyperalimentation and somatostatin. This often cures the problem. If considerable improvement has not occurred within 2-3 weeks, surgery should be performed. A preoperative ERCP is essential to demonstrate the site of the leak. If it is not entirely obvious from the films taken during ERCP, a CT scan should be performed immediately afterward, while contrast media is still in the pancreatic duct. The greater sensitivity of the CT scan will be enough to reveal the tiny trickle from the pancreatic duct into the abdomen. The operation involves suturing a Roux-en-Y limb of jejunum to the site of the leak on the surface of the pancreas or a pancreatic pseudocyst. With appropriate therapy, the outlook is excellent. The death rate is low in patients treated before debilitation becomes severe.
Chronic pleural effusions of pancreatic origin represent a variant in which the pancreatic fistula drains into the chest. The diagnosis is made by measuring high concentrations of amylase (usually > 3000 IU/dL) in the fluid. A CT scan of the pancreas and retrograde pancreatogram should be obtained. Medical therapy consists of draining the fluid with a chest tube, somatostatin, and total parenteral nutrition. If after several weeks the fistula persists or if it recurs after the tube has been removed, the source of the leak on the pancreas should either be drained into a Roux-en-Y limb of jejunum or excised as part of a distal pancreatectomy.
AR Operative management of acute pancreatitis. Surg Clin North Am 2003;93(3):595–610.
ESSENTIALS OF DIAGNOSIS
Persistent or recurrent abdominal pain
Pancreatic calcification on x-ray in 50%
Pancreatic insufficiency in 30%; malabsorption and diabetes mellitus
Most often due to alcoholism
Chronic alcoholism causes most cases of chronic pancreatitis, but a few are due to gallstones, hypercalcemia, hyperlipidemia, duct obstruction from any cause, or inherited predisposition (familial pancreatitis). Direct trauma to the gland, either from an external blow or from surgical injury, can produce chronic pancreatitis if a ductal stricture develops during the healing process. In such cases, disease is often localized to the segment of gland drained by the obstructed duct. Although gallstone disease may cause repeated attacks of acute pancreatitis, this uncommonly leads to chronic pancreatitis.
Pressure within the duct is increased in patients with chronic pancreatitis (about 40 cm H2O) compared with normal subjects (about 15 cm H2O). This is a result of increased viscosity of pancreatic juice, partial obstruction by calculi, and impaired distensibility of the gland because of diffuse fibrosis. Sphincteric pressure remains in the normal range. The increased pressure causes dilation of the duct in the patient whose pancreas has not yet become fixed by scarring. It may also impair nutrient blood flow, causing further functional damage. Pathologic changes in the gland include destruction of parenchyma, fibrosis, dedifferentiation of acini, calculi, and ductal dilation.
Chronic pancreatitis may be asymptomatic, or it may produce abdominal pain, malabsorption, diabetes mellitus, or (usually) all three manifestations. The pain is typically felt deep in the upper abdomen and radiating through to the back, and it waxes and wanes from day to day. Early in the course of the disease, the pain may be episodic, lasting for days to weeks and then vanishing for several months before returning again. Attacks of acute pancreatitis may occur, superimposed on the pattern of chronic pain. Many patients become addicted to the narcotics prescribed for pain.
Abnormal laboratory findings may result from: (1) pancreatic inflammation, (2) pancreatic exocrine insufficiency, (3) diabetes mellitus, (4) bile duct obstruction, or (5) other complications such as pseudocyst formation or splenic vein thrombosis.
In acute exacerbations, serum and urinary amylase levels may be elevated, but most often they are not, perhaps because pancreatic fibrosis has destroyed so much of the enzyme-forming capacity of the parenchyma.
2. Tests of exocrine pancreatic function
The secretin and CCK stimulation tests are the most sensitive tests to detect exocrine malfunction but are difficult to perform.
About 75% of patients with calcific pancreatitis and 30% of those with noncalcific pancreatitis have insulin-dependent diabetes. Most of the rest have either abnormal glucose tolerance curves or abnormally low serum insulin levels after a test meal. The margin of reserve is such that partial pancreatectomy is quite likely to convert a patient who does not require insulin into one who does require it postoperatively.
Elevated bilirubin or alkaline phosphatase levels may result from fibrotic entrapment of the lower end of the bile duct. The differential diagnosis of biliary obstruction in these patients must consider acute pancreatic inflammation, pseudocyst, or pancreatic neoplasm.
Splenic vein thrombosis may produce secondary hypersplenism or gastric varices.
MRCP or endoscopic retrograde pancreatography is helpful in establishing the diagnosis of chronic pancreatitis, in ruling out pancreatic pseudocyst and neoplasm, and in preoperative planning for patients thought to be candidates for surgery. The typical findings are ductal stones and irregularity, with dilation and stenoses and, occasionally, ductal occlusion. The discovery of small, unsuspected pseudocysts is common. Retrograde cholangiography should be performed simultaneously to determine whether the common bile duct is narrowed by the pancreatitis, to determine whether biliary calculi are present, and to aid the surgeon in avoiding injury to the bile duct during operation.
The principal complications of chronic pancreatitis are pancreatic pseudocyst, biliary obstruction, duodenal obstruction, malnutrition, and diabetes mellitus. Adenocarcinoma of the pancreas occurs with greater frequency in patients with familial chronic pancreatitis than in the general population.
Malabsorption and steatorrhea are managed with support and measures. Controlled trials have shown that administering pancreatic enzymes has little effect on the pain.
Patients with chronic pancreatitis should be urged to discontinue the use of alcohol. Abstention from alcohol will reduce chronic or episodic pain in more than half of cases even though damage to the pancreas is irreversible. Psychiatric treatment may be beneficial. Diabetes in these patients usually requires insulin.
Surgical therapy is principally of value to relieve chronic intractable pain. It is essential that every effort be made to eliminate alcohol abuse. The best surgical candidates are those whose pain persists after alcohol has been abandoned.
Surgical treatment in most cases involves a procedure that facilitates drainage of the pancreatic duct or resects diseased pancreas or that serves both purposes. The choice of operation can usually be made preoperatively based on the findings of a retrograde pancreatogram and CT scans. Coincidental bile duct obstruction is common and should be treated by simultaneous choledochoduodenostomy.
A dilated ductal system reflects obstruction, and when dilation is present, procedures to improve ductal drainage usually relieve pain. Calcific alcoholic pancreatitis most often falls into this category.
The usual finding is an irregular, widely dilated duct (1-2 cm in diameter) with points of stenosis (“chain of lakes” appearance) and ductal calculi. For such patients, a longitudinal pancreaticojejunostomy (Puestow procedure) is appropriate (Figure 26–4). The duct is opened anteriorly from the tail into the head of the gland and anastomosed side-to-side to a Roux-en-Y segment of proximal jejunum. Pain improves postoperatively in about 80% of patients, but improvement of pancreatic insufficiency is uncommon. This procedure, however, has a low rate of success when the pancreatic duct is narrow (ie, < 8 mm).
Sphincteroplasty and distal (caudal) pancreaticojejunostomy (DuVal procedure) are other drainage techniques that were used more often in the past. The latter is only of historical interest, but surgical sphincteroplasty plus extraction of pancreatic ductal calculi continues in use, more often now through endoscopic access to the pancreatic duct.
In the absence of a dilated duct, pancreatectomy is the best procedure, and the extent of resection can often be determined from a CT scan and pancreatogram. In patients with small ducts, the most severe disease is usually located in the head of the gland, and pancreaticoduodenectomy (Whipple procedure) is the operation of choice. A variant of this procedure involves resection of the head of the gland while preserving the duodenum. A Roux-en-Y limb of jejunum is anastomosed to both cut surfaces of the pancreas. If the duct is also dilated in the body and tail, resection of the head can also be combined with longitudinal pancreaticojejunostomy in that part of the gland. Pain relief is satisfactory in about 80% of patients treated by these operations. Total pancreatectomy is indicated when a previous pancreaticoduodenectomy or distal pancreatectomy has failed to give satisfactory pain relief. The reported results are contradictory; pain relief has been excellent in reports from the United Kingdom but less than excellent in reports from the United States. Difficulties in controlling diabetes mellitus occur in 30%-40% of patients who have had total pancreatectomy and are responsible for occasional deaths. For this reason, total pancreatectomy is contraindicated in unreformed alcoholics. For chronic alcoholic pancreatitis, resections from the left of the gland—eg, distal subtotal pancreatectomy—are much less successful than resections of the head and are rarely performed nowadays. The most common indication is chronic focal posttraumatic pancreatitis, in which the head may be normal.
Celiac plexus block may be used in an attempt to obtain pain relief before proceeding with a major pancreatic resection in small duct pancreatitis.
Longitudinal pancreaticojejunostomy (Puestow) for chronic pancreatitis.
Longitudinal pancreaticojejunostomy relieves pain in about 80% of patients with a dilated duct. Weight gain is common but less predictable. The results of pancreaticoduodenectomy are good in 80% of patients, but removal of the distal pancreas is less successful. Total pancreatectomy, which is principally reserved for failures of other operations, gives satisfying relief in 30%-90% of patients depending on the series. The reasons for these widely differing results are not known. Celiac plexus block is of lasting benefit to no more than 30% of patients. In some patients, pain subsides with advancing pancreatic insufficiency.
Except in advanced cases with continuous pain, alcoholics who can be persuaded to stop drinking often experience relief from pain and recurrent attacks of pancreatitis. In familial pancreatitis, the progress of the disease is inexorable, and many of these patients require surgery. The results of longitudinal pancreaticojejunostomy are excellent in familial pancreatitis. Narcotic addiction, diabetes, and malnutrition are serious problems in many patients.
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