# Seminar 13: Pancreatic Surgery ## General Surgery Clerkship - Unit 13 --- ## Learning Objectives By the end of this seminar, students will be able to: 1. Describe pancreatic anatomy including ductal systems, blood supply, and critical anatomical relationships 2. Diagnose acute pancreatitis using established criteria and classify severity to guide management decisions 3. Apply evidence-based management principles for acute pancreatitis including fluid resuscitation, nutrition, and intervention timing 4. Recognize the clinical features and complications of chronic pancreatitis and select appropriate surgical procedures 5. Evaluate pancreatic cancer resectability and describe the principles of pancreaticoduodenectomy 6. Differentiate pancreatic cystic lesions and apply appropriate surveillance or treatment strategies --- ## Seminar Outline ### I. Pancreatic Anatomy and Embryology The pancreas is a retroperitoneal organ extending transversely across the upper abdomen from the duodenal C-loop to the splenic hilum, measuring approximately fifteen to twenty centimeters in length. The gland is divided into four anatomical regions with distinct surgical implications: the head lies within the duodenal curve and includes the uncinate process extending posterior to the superior mesenteric vessels, the neck overlies the confluence of the portal vein and superior mesenteric vein, the body extends leftward anterior to the aorta and left renal vein, and the tail reaches the splenic hilum where it may be closely adherent to splenic vessels. Understanding these relationships is essential for surgical planning in both benign and malignant pancreatic disease. The pancreas develops from two embryological buds arising from the primitive foregut during the fourth week of gestation. The dorsal pancreatic bud gives rise to the body, tail, and superior portion of the head, while the ventral bud, which rotates with the developing bile duct, forms the uncinate process and inferior portion of the head. Fusion of these buds results in anastomosis of their ductal systems, with the ventral duct becoming the main pancreatic duct of Wirsung and the proximal dorsal duct becoming the accessory duct of Santorini. Failure of ductal fusion results in pancreas divisum, present in approximately ten percent of the population, where the majority of pancreatic drainage occurs through the minor papilla and may predispose to recurrent pancreatitis in a subset of patients. The main pancreatic duct of Wirsung courses through the center of the gland from tail to head, receiving tributaries from the pancreatic parenchyma along its length. The duct typically measures two to three millimeters in diameter in the head, tapering toward the tail, and joins the common bile duct at the ampulla of Vater before entering the duodenum through the major papilla. The sphincter of Oddi controls flow from both pancreatic and biliary systems into the duodenum. Annular pancreas represents another developmental anomaly where pancreatic tissue encircles the duodenum, potentially causing obstruction, and results from failure of the ventral bud to rotate properly during embryogenesis. The endocrine function of the pancreas resides in the islets of Langerhans, which comprise approximately two percent of pancreatic mass but receive approximately fifteen percent of pancreatic blood flow. Beta cells produce insulin for glucose homeostasis, alpha cells secrete glucagon, delta cells release somatostatin, and PP cells produce pancreatic polypeptide. The exocrine pancreas comprises acinar cells producing digestive enzymes including amylase, lipase, and proteases in inactive zymogen forms, along with ductal cells that secrete bicarbonate-rich fluid for enzyme transport and duodenal pH neutralization. Regulation occurs through vagal innervation and hormonal signals including cholecystokinin and secretin released from duodenal enteroendocrine cells in response to intraluminal nutrients. Panel A: Anatomical illustration of the pancreas showing head with uncinate process, neck overlying portal vein confluence, body, and tail extending to splenic hilum with surrounding structures labeled. Panel B: Embryological development diagram demonstrating dorsal and ventral pancreatic bud fusion with resulting ductal anatomy and common variants. Panel C: Cross-sectional view showing main pancreatic duct course with ampullary anatomy and sphincter of Oddi relationship to common bile duct. Panel D: Histological representation of pancreatic parenchyma showing acinar cells, islets of Langerhans, and ductal structures with cellular composition. --- ### II. Pancreatic Blood Supply and Surgical Relationships The arterial supply to the pancreas derives from both celiac and superior mesenteric arterial systems, reflecting the organ's position at the junction of foregut and midgut embryological territories. The pancreaticoduodenal arcades provide the primary blood supply to the pancreatic head and duodenum, with the superior pancreaticoduodenal arteries arising from the gastroduodenal artery as terminal branches of the celiac axis, and the inferior pancreaticoduodenal arteries arising from the first jejunal branch of the superior mesenteric artery. These arcades anastomose within the pancreatic head, creating collateral pathways that have implications for both pancreatic resection and management of celiac artery stenosis. The body and tail of the pancreas receive arterial supply predominantly from branches of the splenic artery, which courses along the superior border of the gland with a characteristically tortuous path. The dorsal pancreatic artery, great pancreatic artery of von Haller, and transverse pancreatic artery provide segmental supply to the pancreatic body. The caudal pancreatic arteries, arising from the splenic artery or its terminal branches near the splenic hilum, supply the pancreatic tail. The intimate relationship between the splenic artery and pancreatic body explains why distal pancreatectomy typically includes splenectomy, though splenic preservation may be achieved in select cases by preserving the splenic vessels or relying on collateral flow through the short gastric arteries. The portal venous system has critical relationships with the pancreas that determine resectability of pancreatic malignancies. The superior mesenteric vein ascends anterior to the uncinate process and posterior to the pancreatic neck, joining the splenic vein posterior to the pancreatic neck to form the portal vein. This confluence, along with the first several centimeters of portal vein, lies in a groove on the posterior surface of the pancreas and represents a key structure during pancreaticoduodenectomy. Tumor involvement of the superior mesenteric vein or portal vein confluence was historically considered unresectable but is now amenable to vascular resection and reconstruction in appropriately selected patients at experienced centers. The superior mesenteric artery represents the most critical vascular structure in determining resectability of pancreatic head tumors. This vessel arises from the anterior aorta at the level of the first lumbar vertebra, courses posterior to the pancreatic neck and anterior to the uncinate process, and gives off the inferior pancreaticoduodenal artery before branching into jejunal, ileal, and colic vessels. Tumor encasement of the superior mesenteric artery beyond one hundred eighty degrees generally precludes curative resection due to the impossibility of achieving negative margins without arterial resection, which carries prohibitive morbidity. The celiac axis and hepatic artery represent additional vascular structures whose involvement influences surgical planning and determines classification of tumors as resectable, borderline resectable, or locally advanced. Panel A: Arterial anatomy showing celiac axis and superior mesenteric artery branches supplying the pancreas with pancreaticoduodenal arcades highlighted. Panel B: Splenic artery course along superior pancreatic border with branches to pancreatic body and tail illustrated. Panel C: Venous anatomy demonstrating portal vein formation from superior mesenteric and splenic vein confluence posterior to pancreatic neck. Panel D: Cross-sectional view at pancreatic neck level showing relationship of superior mesenteric artery, superior mesenteric vein, and aorta to determine resectability. --- ### III. Acute Pancreatitis Etiology and Diagnosis Acute pancreatitis represents inflammation of the pancreatic parenchyma with variable involvement of surrounding tissues and potential for systemic inflammatory response and multiorgan failure. The incidence has increased over recent decades with approximately 300,000 hospital admissions annually in the United States, making it one of the most common gastrointestinal causes of hospitalization. Gallstones and alcohol consumption account for approximately seventy to eighty percent of cases, with gallstones representing the most common etiology at approximately forty percent and alcohol accounting for approximately thirty percent. Identification of the underlying etiology is essential to guide management and prevent recurrence. The pathophysiology of acute pancreatitis involves premature activation of digestive enzymes within the pancreatic parenchyma, leading to autodigestion, inflammation, and potentially necrosis. In gallstone pancreatitis, transient obstruction at the ampulla by a passing stone triggers the inflammatory cascade. Alcohol appears to sensitize acinar cells to premature zymogen activation through multiple mechanisms including oxidative stress and ductal protein precipitation. Additional etiologies include post-ERCP pancreatitis occurring in three to five percent of diagnostic procedures, hypertriglyceridemia with levels typically exceeding one thousand milligrams per deciliter, hypercalcemia, medications, autoimmune pancreatitis, genetic mutations in susceptibility genes, and anatomical variants including pancreas divisum. The mnemonic I GET SMASHED helps recall the major etiologies. Diagnosis of acute pancreatitis requires two of three Atlanta criteria: characteristic abdominal pain typically described as severe epigastric pain radiating to the back, elevated serum lipase or amylase greater than three times the upper limit of normal, and characteristic imaging findings on CT, MRI, or ultrasound. Lipase is preferred over amylase due to higher sensitivity and specificity and longer elevation following symptom onset. Imaging is not required for diagnosis when clinical and laboratory criteria are met and should not delay initial management. CT imaging is typically reserved for patients who fail to improve as expected or when complications are suspected, with optimal timing at seventy-two to ninety-six hours when extent of pancreatic necrosis can be accurately assessed. The initial diagnostic workup should focus on identifying the underlying etiology to guide management and prevent recurrence. Transabdominal ultrasound should be performed in all patients to evaluate for gallstones, as identification of cholelithiasis establishes the etiology and mandates cholecystectomy during the index admission for mild disease. Liver function tests may suggest biliary etiology even when ultrasound is negative, with alanine aminotransferase elevation greater than three times normal having high positive predictive value for gallstone pancreatitis. Serum triglyceride and calcium levels should be measured, particularly when gallstone and alcohol etiologies have been excluded. A careful medication history may reveal drug-induced pancreatitis requiring discontinuation of the offending agent. Panel A: Pie chart showing relative contributions of major etiologies of acute pancreatitis with gallstones, alcohol, and other causes represented. Panel B: Pathophysiology diagram illustrating premature zymogen activation within acinar cells leading to autodigestion and inflammatory cascade. Panel C: Atlanta diagnostic criteria presented with clinical, laboratory, and imaging components with thresholds for lipase elevation. Panel D: Initial diagnostic algorithm showing ultrasound for gallstones, liver function tests, triglycerides, calcium, and medication review with etiology determination pathway. --- ### IV. Acute Pancreatitis Severity and Management Severity classification according to the revised Atlanta criteria stratifies patients into mild, moderately severe, and severe categories based on organ failure and local complications. Mild acute pancreatitis, occurring in approximately eighty percent of cases, is characterized by absence of organ failure and local complications with resolution typically within one week. Moderately severe pancreatitis involves transient organ failure resolving within forty-eight hours or local complications without persistent organ failure. Severe acute pancreatitis, occurring in approximately twenty percent of cases, is defined by persistent organ failure lasting beyond forty-eight hours and carries mortality rates of twenty to forty percent. Early identification of patients at risk for severe disease enables appropriate triage and monitoring. Prognostic scoring systems assist in early identification of patients likely to develop severe disease, though no system provides perfect prediction. The Bedside Index for Severity in Acute Pancreatitis score incorporates blood urea nitrogen greater than twenty-five, impaired mental status, systemic inflammatory response syndrome, age greater than sixty years, and pleural effusion to identify high-risk patients within the first twenty-four hours. The Ranson criteria assess factors at admission and forty-eight hours but require two time points for completion. Elevated hematocrit reflecting hemoconcentration from third-spacing, blood urea nitrogen greater than twenty indicating renal hypoperfusion, and elevated serum creatinine all predict severe disease. Persistent systemic inflammatory response syndrome at forty-eight hours strongly correlates with development of organ failure and mortality. Initial management of acute pancreatitis centers on aggressive fluid resuscitation to counteract the massive third-space losses characteristic of the systemic inflammatory response. Lactated Ringer solution is preferred over normal saline based on evidence of reduced inflammatory markers and potentially improved outcomes. Early goal-directed fluid administration targeting urine output of 0.5 to 1 milliliter per kilogram per hour, decreasing blood urea nitrogen, and normalizing heart rate has been shown to improve outcomes. However, excessive fluid administration may lead to complications including pulmonary edema and abdominal compartment syndrome, necessitating careful titration. Pain management with opioid analgesics and nothing by mouth status until pain improves comprise additional supportive measures. Nutritional support has evolved significantly based on recognition that bowel rest does not improve outcomes and may worsen disease severity by compromising gut barrier function. Early enteral nutrition, initiated within twenty-four to seventy-two hours regardless of severity, maintains intestinal mucosal integrity, reduces bacterial translocation, and decreases infectious complications. Nasogastric feeding is acceptable and equivalent to nasojejunal feeding in most patients, with nasojejunal access reserved for patients with gastric outlet obstruction or persistent intolerance. Parenteral nutrition should be avoided unless enteral feeding is impossible for greater than seven days due to increased infectious complications and cost. Routine prophylactic antibiotics are not indicated even in severe pancreatitis, as they do not reduce mortality and may promote resistant organisms. Panel A: Revised Atlanta severity classification showing mild, moderately severe, and severe categories with defining features and associated mortality rates. Panel B: BISAP score components with point values and correlation between score and mortality risk. Panel C: Fluid resuscitation protocol illustrating initial bolus, goal-directed maintenance, and monitoring parameters with targets. Panel D: Enteral nutrition pathway showing early initiation, nasogastric versus nasojejunal routes, and avoidance of parenteral nutrition except when enteral impossible. --- ### V. Local Complications of Acute Pancreatitis Local complications of acute pancreatitis are classified according to the revised Atlanta criteria based on timing, presence of necrosis, and encapsulation. Acute peripancreatic fluid collections develop within the first four weeks and consist of peripancreatic fluid without necrotic material and without a defined wall. These collections are common and typically resolve spontaneously without intervention. Pseudocysts develop after four weeks, representing encapsulated collections of amylase-rich fluid without solid necrotic debris, and should be distinguished from cystic neoplasms. Acute necrotic collections contain necrotic pancreatic or peripancreatic tissue and develop within four weeks, while walled-off necrosis represents mature encapsulated necrotic collections after four weeks and may contain variable amounts of solid and liquid material. Necrotizing pancreatitis occurs in approximately five to ten percent of patients with acute pancreatitis and carries significantly higher morbidity and mortality than interstitial pancreatitis. CT with intravenous contrast performed after seventy-two to ninety-six hours demonstrates non-enhancing pancreatic parenchyma indicating necrosis, allowing classification of extent and location. Approximately sixty to seventy percent of necrotizing pancreatitis remains sterile throughout the disease course and can often be managed conservatively without intervention. Infected necrosis, developing in approximately thirty percent of necrotizing pancreatitis cases typically after seven to ten days, represents the major indication for intervention and is suggested by clinical deterioration, gas within necrotic collections on imaging, or positive culture from image-guided aspiration. The step-up approach has revolutionized management of infected pancreatic necrosis, replacing early open necrosectomy with a graduated intervention strategy. Initial management involves percutaneous or endoscopic drainage of infected collections, with drain placement guided by CT or endoscopic ultrasound. Many patients will respond to drainage alone combined with antibiotics, avoiding the need for necrosectomy. When drainage is insufficient, minimally invasive necrosectomy through video-assisted retroperitoneal debridement, endoscopic transgastric necrosectomy, or laparoscopic approaches provides definitive source control with lower morbidity than open surgical necrosectomy. The timing principle of delaying intervention until at least four weeks when possible allows demarcation and liquefaction of necrotic material, facilitating debridement and reducing morbidity. Interventions for non-infected pancreatic fluid collections and walled-off necrosis are indicated for symptomatic collections causing pain, gastric outlet obstruction, or biliary obstruction, and for collections preventing oral intake. Pseudocysts may be drained endoscopically through transgastric or transduodenal cystgastrostomy when the collection abuts the gastric or duodenal wall. Surgical cystgastrostomy or cystjejunostomy provides an alternative when endoscopic approach is not feasible. Walled-off necrosis containing significant solid debris often requires necrosectomy rather than simple drainage. Asymptomatic collections, regardless of size, may be observed without intervention as many will resolve spontaneously over weeks to months. Panel A: Atlanta classification of local complications showing acute peripancreatic fluid collection, pseudocyst, acute necrotic collection, and walled-off necrosis with imaging examples and temporal definitions. Panel B: CT scan demonstrating necrotizing pancreatitis with non-enhancing pancreatic parenchyma and peripancreatic necrotic collection. Panel C: Step-up approach algorithm from percutaneous drainage through minimally invasive necrosectomy to open necrosectomy with decision points. Panel D: Endoscopic transgastric drainage and necrosectomy technique showing EUS-guided access, cystgastrostomy creation, and debridement instrumentation. --- ### VI. Gallstone Pancreatitis and Chronic Pancreatitis Gallstone pancreatitis requires specific management considerations beyond general supportive care due to the need to address the underlying biliary pathology to prevent recurrence. Patients with concurrent cholangitis manifesting as Charcot's triad should undergo urgent endoscopic retrograde cholangiopancreatography within twenty-four hours for biliary decompression. For patients without cholangitis, routine early ERCP does not improve outcomes and is reserved for those with persistent biliary obstruction suggested by persistently elevated or rising bilirubin. Cholecystectomy should be performed during the index hospitalization for patients with mild gallstone pancreatitis to prevent recurrence, as the risk of recurrent pancreatitis reaches approximately thirty percent within six weeks if cholecystectomy is delayed. For severe gallstone pancreatitis, cholecystectomy is delayed until inflammation resolves and the patient has recovered, typically four to six weeks. Chronic pancreatitis represents progressive inflammatory destruction of the pancreatic parenchyma leading to irreversible structural and functional changes. Alcohol consumption accounts for approximately seventy percent of cases in Western countries, with risk increasing with quantity and duration of consumption. Genetic factors including mutations in PRSS1, SPINK1, and CFTR contribute to hereditary and idiopathic chronic pancreatitis. Autoimmune pancreatitis represents a distinct entity with characteristic imaging findings, elevated immunoglobulin G4 levels, and response to steroids. The TIGAR-O classification system categorizes etiologies as toxic-metabolic, idiopathic, genetic, autoimmune, recurrent acute, and obstructive, providing a framework for comprehensive evaluation. Clinical manifestations of chronic pancreatitis include chronic abdominal pain as the predominant symptom, typically epigastric with radiation to the back and exacerbation with meals. Exocrine insufficiency develops as progressive parenchymal destruction reduces enzyme secretion below the threshold needed for adequate digestion, manifesting as steatorrhea, weight loss, and fat-soluble vitamin deficiencies. Endocrine insufficiency with development of diabetes typically occurs later in the disease course as islet cell mass is destroyed. Pancreatic duct strictures, calcifications, and pseudocysts represent structural complications visible on imaging. Pain may paradoxically improve in late-stage disease as progressive glandular destruction reduces inflammatory activity, termed burnout. Medical management of chronic pancreatitis addresses pain control, enzyme replacement, and diabetes management. Analgesic therapy progresses from non-opioid medications through opioids with recognition of the significant addiction potential in this often socially vulnerable population. Pancreatic enzyme replacement therapy with lipase supplementation during meals addresses malabsorption, with adequate dosing typically requiring 25,000 to 50,000 units of lipase per meal. Abstinence from alcohol and tobacco is essential to slow disease progression. Endoscopic therapy including stricture dilation, stone extraction, and stent placement may provide pain relief in selected patients with ductal obstruction, though outcomes in chronic pancreatitis are less favorable than in acute biliary disease. Panel A: Gallstone pancreatitis management algorithm showing ERCP indications for cholangitis versus routine cases and cholecystectomy timing based on severity. Panel B: TIGAR-O etiological classification of chronic pancreatitis with examples in each category. Panel C: Natural history diagram of chronic pancreatitis showing progression from recurrent acute inflammation through fibrosis to exocrine and endocrine insufficiency. Panel D: CT scan features of chronic pancreatitis including parenchymal atrophy, calcifications, dilated pancreatic duct, and pseudocyst. --- ### VII. Surgical Treatment of Chronic Pancreatitis Surgical intervention for chronic pancreatitis is indicated when medical and endoscopic management fail to control symptoms, primarily intractable pain that significantly impairs quality of life. Additional indications include symptomatic or complicated pseudocysts, biliary obstruction from fibrotic stricture of the intrapancreatic common bile duct, duodenal obstruction from inflammatory mass in the pancreatic head, and concern for malignancy that cannot be excluded by imaging or biopsy. Patient selection requires careful assessment of pain etiology, as some patients have predominant central sensitization or opioid-induced hyperalgesia that will not respond to surgical intervention. Complete abstinence from alcohol is strongly associated with improved pain outcomes following surgery. Drainage procedures are appropriate when the predominant pathology involves main pancreatic duct dilation without significant inflammatory mass in the pancreatic head. The lateral pancreaticojejunostomy, known as the Puestow procedure or modified Puestow, involves longitudinal opening of a dilated pancreatic duct and creation of a side-to-side anastomosis to a Roux-en-Y jejunal limb, providing drainage along the entire length of the duct. This procedure is indicated when the main pancreatic duct diameter exceeds seven millimeters, a threshold termed the chain of lakes appearance when alternating strictures and dilations are present. The Puestow procedure provides durable pain relief in approximately seventy to eighty percent of appropriately selected patients with minimal loss of pancreatic parenchyma and preservation of endocrine and exocrine function. Combined drainage and resection procedures address the common scenario of ductal dilation combined with inflammatory mass in the pancreatic head, the so-called big duct, big head chronic pancreatitis. The Frey procedure combines lateral pancreaticojejunostomy with coring out of the pancreatic head, removing inflammatory tissue while preserving the duodenum and bile duct. The Beger procedure involves resection of the pancreatic head with preservation of the duodenum, requiring division of the pancreas over the portal vein and reconstruction with Roux-en-Y jejunal limb anastomosis to both the proximal pancreatic remnant and rim of preserved pancreatic head. Both procedures provide excellent pain relief exceeding eighty percent while preserving duodenum, stomach, and bile duct continuity and minimizing long-term endocrine and exocrine insufficiency. Resection procedures are appropriate when malignancy cannot be excluded, when the disease is predominantly located in the head or tail without significant ductal dilation, or when combined procedures are not feasible. Pancreaticoduodenectomy removes the pancreatic head and neck along with duodenum, distal stomach or pylorus, distal common bile duct, and gallbladder, and is indicated for head-dominant disease or suspected malignancy. Distal pancreatectomy with or without splenectomy addresses tail-dominant disease. Total pancreatectomy with islet autotransplantation represents an option for diffuse disease, removing all pancreatic parenchyma to eliminate the pain source while islet isolation and hepatic infusion provide potential preservation of insulin production and prevention of diabetes. Panel A: Surgical selection algorithm based on duct diameter, presence of inflammatory head mass, and disease distribution with procedure recommendations. Panel B: Puestow lateral pancreaticojejunostomy technique showing longitudinal pancreatic duct opening and Roux-en-Y jejunal anastomosis. Panel C: Frey procedure illustration demonstrating head coring combined with longitudinal pancreaticojejunostomy. Panel D: Comparison diagram of Beger versus Frey procedures showing extent of head resection and reconstruction differences. --- ### VIII. Pancreatic Cancer Epidemiology and Diagnosis Pancreatic ductal adenocarcinoma represents one of the most lethal malignancies, ranking as the fourth leading cause of cancer death in the United States with a five-year survival rate of approximately ten percent. The incidence has gradually increased and is projected to become the second leading cause of cancer death by 2030. Risk factors include cigarette smoking which doubles the risk, longstanding diabetes mellitus, chronic pancreatitis, obesity, and family history with approximately ten percent of cases having hereditary components. Hereditary cancer syndromes including familial pancreatic cancer, BRCA2 mutations, hereditary pancreatitis, Lynch syndrome, and Peutz-Jeghers syndrome carry significantly elevated risk and may warrant screening in affected individuals. Clinical presentation of pancreatic cancer varies based on tumor location within the gland. Tumors of the pancreatic head, accounting for approximately seventy percent of cases, typically present with painless obstructive jaundice from compression or invasion of the intrapancreatic common bile duct. Associated symptoms include clay-colored stools, dark urine, pruritus, and weight loss. A palpable, non-tender gallbladder in the setting of jaundice, known as Courvoisier sign, results from gradual biliary obstruction allowing gallbladder distension without the inflammation that occurs with gallstone obstruction. Tumors of the pancreatic body and tail more commonly present with pain from celiac plexus invasion and weight loss, often reaching advanced stage before diagnosis due to absence of early obstructive symptoms. Diagnostic evaluation begins with pancreatic protocol CT scan using thin-slice multidetector technique with arterial and venous phase imaging, which provides essential information regarding tumor size, relationship to mesenteric vessels, and presence of metastatic disease. The characteristic appearance of pancreatic adenocarcinoma is a hypodense mass with associated pancreatic duct and biliary duct dilation, the double duct sign. MRI with MRCP provides complementary information particularly for biliary anatomy and detection of small liver metastases. Serum CA 19-9 is elevated in approximately eighty percent of patients with pancreatic cancer and serves as a baseline for monitoring treatment response and surveillance, though false elevations occur with biliary obstruction and false negatives in Lewis antigen-negative patients. Tissue diagnosis is obtained through endoscopic ultrasound with fine needle aspiration, which provides high sensitivity for detecting pancreatic masses and obtaining cytological confirmation of malignancy. Biopsy is essential before neoadjuvant therapy for borderline resectable or locally advanced tumors but may be omitted when proceeding directly to surgical resection for clearly resectable disease based on imaging characteristics strongly suggestive of malignancy. Staging laparoscopy may identify peritoneal metastases not visible on cross-sectional imaging, particularly for tumors of the body and tail which have higher rates of occult metastatic disease. PET-CT has a limited role in pancreatic cancer staging but may identify distant metastases in select cases. Panel A: Epidemiology showing pancreatic cancer incidence trends and comparison of survival rates with other common malignancies. Panel B: Clinical presentation comparison between pancreatic head tumors with jaundice versus body and tail tumors with pain and weight loss. Panel C: Pancreatic protocol CT demonstrating hypodense pancreatic head mass with double duct sign and mesenteric vessel relationships. Panel D: EUS-FNA technique showing echoendoscope positioning, needle passage through gastric wall, and cytological sampling of pancreatic mass. --- ### IX. Pancreatic Cancer Staging and Surgical Treatment Resectability classification determines the initial treatment approach and is based on relationship of the tumor to critical vascular structures. Resectable tumors demonstrate no arterial contact with the celiac axis, superior mesenteric artery, or common hepatic artery, and no venous contact with the superior mesenteric vein or portal vein, or less than one hundred eighty degrees contact without vein contour irregularity. Borderline resectable tumors have greater vascular involvement that may be amenable to resection with vascular reconstruction but carry higher risk of positive margins. Locally advanced tumors have vascular involvement precluding curative resection, typically defined as greater than one hundred eighty degrees arterial encasement or unreconstructible venous involvement. Metastatic disease is present in approximately fifty percent of patients at diagnosis. Surgical resection offers the only chance for long-term survival in pancreatic cancer, though only fifteen to twenty percent of patients present with resectable disease. Pancreaticoduodenectomy, known as the Whipple procedure, is the standard operation for tumors of the pancreatic head and uncinate process. The resection includes the pancreatic head and neck, duodenum, distal stomach or pylorus, distal common bile duct, and gallbladder, along with regional lymph nodes. Reconstruction requires three anastomoses: pancreaticojejunostomy or pancreaticogastrostomy for the pancreatic remnant, hepaticojejunostomy for biliary drainage, and gastrojejunostomy or duodenojejunostomy for alimentary continuity. The pylorus-preserving variant maintains gastric continuity and may reduce dumping symptoms. Operative outcomes for pancreaticoduodenectomy have improved dramatically with mortality rates of less than three percent at high-volume centers, though morbidity remains approximately thirty to forty percent. Pancreatic fistula represents the most clinically significant complication, occurring in fifteen to twenty percent of patients and graded according to the International Study Group on Pancreatic Fistula definition based on clinical impact. Risk factors for fistula include soft pancreatic texture, small duct diameter, and high-risk pathology including ampullary tumors. Delayed gastric emptying affects approximately twenty percent of patients and typically resolves with conservative management. Postoperative hemorrhage and bile leak represent additional complications requiring prompt recognition and management. Neoadjuvant therapy has become increasingly utilized, particularly for borderline resectable disease where upfront resection carries high risk of positive margins and early recurrence. Regimens including FOLFIRINOX or gemcitabine with nab-paclitaxel provide systemic treatment of micrometastatic disease and may achieve sufficient downstaging to enable subsequent resection. Adjuvant chemotherapy with modified FOLFIRINOX or gemcitabine-based regimens is recommended for all patients following resection based on demonstrated survival benefit. Despite optimal surgical and systemic therapy, five-year survival following resection reaches only twenty to twenty-five percent, reflecting the aggressive biology of pancreatic adenocarcinoma and high rates of systemic recurrence. Panel A: Vascular criteria for resectability classification showing arterial and venous relationships that define resectable, borderline resectable, and locally advanced categories. Panel B: Pancreaticoduodenectomy resection extent showing structures removed including pancreatic head, duodenum, distal stomach, and distal bile duct. Panel C: Reconstruction following Whipple procedure illustrating pancreaticojejunostomy, hepaticojejunostomy, and gastrojejunostomy configurations. Panel D: Survival curves comparing resected pancreatic cancer with adjuvant therapy versus locally advanced and metastatic disease outcomes. --- ### X. Pancreatic Cystic Lesions Pancreatic cystic lesions are increasingly identified due to widespread use of cross-sectional imaging, with prevalence on abdominal imaging reaching approximately fifteen percent in patients over age seventy. The differential diagnosis includes true cystic neoplasms with variable malignant potential, inflammatory pseudocysts lacking epithelial lining, and congenital or retention cysts. Distinguishing these entities is essential as management ranges from surgical resection for high-risk lesions to surveillance for low-risk cysts to treatment of underlying pancreatitis for pseudocysts. The most commonly encountered cystic neoplasms include serous cystadenomas, mucinous cystic neoplasms, intraductal papillary mucinous neoplasms, and solid pseudopapillary neoplasms. Serous cystadenomas are benign tumors composed of glycogen-rich cuboidal epithelium forming multiple small cysts with a characteristic microcystic or honeycomb appearance on imaging. A central stellate scar with calcification is pathognomonic when present. These lesions occur predominantly in women with mean age of diagnosis in the sixth decade. Serous cystadenomas have negligible malignant potential and do not require resection unless symptomatic from mass effect or when diagnosis is uncertain. The macrocystic variant may be difficult to distinguish from mucinous lesions, requiring careful evaluation of imaging features and cyst fluid analysis. Mucinous cystic neoplasms are characterized by ovarian-type stroma and occur almost exclusively in women, typically in the body or tail of the pancreas without communication with the pancreatic ductal system. These tumors have malignant potential with progression from adenoma through borderline to invasive carcinoma, with the risk of malignancy correlating with size, mural nodules, and presence of solid components. Surgical resection is recommended for all mucinous cystic neoplasms given malignant potential and typically young patient age, with distal pancreatectomy being the most common procedure. Five-year survival exceeds ninety-five percent for non-invasive lesions, while invasive mucinous cystadenocarcinoma has significantly worse prognosis. Intraductal papillary mucinous neoplasms are characterized by communication with the pancreatic ductal system and are classified as main duct, branch duct, or mixed type based on location. Main duct IPMN involves the main pancreatic duct and carries high malignant potential of approximately sixty to seventy percent, warranting surgical resection in operative candidates. Branch duct IPMN communicates with but does not involve the main duct and has lower malignant potential of approximately fifteen to twenty-five percent. Management of branch duct IPMN is guided by the presence of high-risk stigmata including obstructive jaundice, enhancing mural nodule, or main duct dilation greater than ten millimeters, and worrisome features including cyst size greater than three centimeters, main duct dilation of five to nine millimeters, or thickened cyst walls. Surveillance protocols with MRI or EUS allow monitoring of stable lesions without high-risk features. Panel A: Differential diagnosis of pancreatic cystic lesions showing imaging characteristics of serous cystadenoma with microcystic pattern, mucinous cystic neoplasm with macrocystic appearance, and IPMN with ductal communication. Panel B: MRI demonstrating serous cystadenoma with central scar and honeycomb microcystic pattern. Panel C: IPMN classification showing main duct versus branch duct types with corresponding malignant potential and management recommendations. Panel D: Surveillance algorithm for branch duct IPMN based on presence of high-risk stigmata and worrisome features with intervention thresholds. --- ## Summary - The pancreas is divided into head with uncinate process, neck overlying the portal vein confluence, body, and tail extending to the splenic hilum, with critical vascular relationships determining surgical resectability - Acute pancreatitis diagnosis requires two of three Atlanta criteria: characteristic pain, lipase greater than three times normal, or characteristic imaging findings - Severity classification identifies mild, moderately severe, and severe disease based on organ failure duration and local complications - Management centers on aggressive fluid resuscitation with lactated Ringer solution and early enteral nutrition, with intervention delayed in necrotizing pancreatitis - Infected pancreatic necrosis is managed with the step-up approach beginning with percutaneous or endoscopic drainage before proceeding to minimally invasive necrosectomy if needed - Chronic pancreatitis surgical options include Puestow procedure for dilated duct disease and Frey or Beger procedures for combined duct dilation and inflammatory head mass - Pancreatic cancer carries poor prognosis with only fifteen to twenty percent resectable at presentation and five-year survival of approximately ten percent overall - Pancreaticoduodenectomy for head tumors can be performed with less than three percent mortality at high-volume centers, with adjuvant chemotherapy improving survival - Pancreatic cystic lesions require differentiation between benign serous cystadenoma, mucinous cystic neoplasm requiring resection, and IPMN with management based on duct involvement and high-risk features - Main duct IPMN warrants resection due to high malignant potential, while branch duct IPMN may be surveilled in absence of high-risk stigmata --- ## Key Terms | Term | Definition | |------|------------| | Atlanta criteria | Diagnostic criteria for acute pancreatitis requiring two of three: characteristic pain, elevated lipase greater than three times normal, or characteristic imaging | | Walled-off necrosis | Encapsulated pancreatic or peripancreatic necrosis occurring after four weeks with defined wall | | Step-up approach | Graduated intervention strategy for infected pancreatic necrosis progressing from drainage to minimally invasive necrosectomy | | Puestow procedure | Lateral pancreaticojejunostomy for chronic pancreatitis with dilated main pancreatic duct | | Frey procedure | Combined lateral pancreaticojejunostomy with coring of pancreatic head for chronic pancreatitis | | Pancreaticoduodenectomy | Whipple procedure removing pancreatic head, duodenum, distal stomach, and distal bile duct with reconstruction | | Borderline resectable | Pancreatic cancer with vascular involvement potentially amenable to resection with vascular reconstruction | | IPMN | Intraductal papillary mucinous neoplasm characterized by communication with pancreatic ductal system | | Mucinous cystic neoplasm | Pancreatic cystic tumor with ovarian-type stroma occurring in women with malignant potential | | FOLFIRINOX | Chemotherapy regimen combining fluorouracil, leucovorin, irinotecan, and oxaliplatin for pancreatic cancer | --- *This content is subject to the [MIT License](https://opensource.org/licenses/MIT). © 2024–2026 Hibbert School of Medicine.*