Ch28: Pancreatic Diseases（胰腺疾病）

Preparatory Mindset

Pancreatic surgery = acute pancreatitis, chronic pancreatitis, pancreatic cancer (and periampullary carcinoma). The lecture (Junjie Liang, 11KB) covers anatomy, acute pancreatitis, pancreatic cancer, and periampullary carcinoma. This links to Anatomy (Ch17: retroperitoneal pancreas, head in the duodenal C-loop, portal vein behind the neck) and Imaging (CT with contrast = diagnostic for pancreatitis & staging cancer).

Exam mindset: acute pancreatitis (Ranson/Glasgow criteria, CT severity — Balthazar/CTSI, management: fluids + organ support, the "3 causes": gallstones, alcohol, idiopathic), pancreatic cancer (painless obstructive jaundice, Courvoisier's law, CA19-9, Whipple operation, poor prognosis), and periampullary tumors (better prognosis than pancreatic head cancer — earlier jaundice).

Core Concepts

1. Anatomy (MUST KNOW)

• Pancreas: retroperitoneal, behind the lesser sac & stomach; head in the C-loop of the duodenum (shares blood supply — celiac & SMA); uncinate process; neck (SMV + splenic → portal vein behind the neck); body & tail (in front of the aorta, left kidney; tail reaches the splenic hilum)
• Ducts: ventral duct joins the common bile duct → major papilla (of Vater); dorsal duct → main pancreatic duct; accessory duct (Santorini) → minor papilla, 2.5 cm proximal
• Blood supply: pancreaticoduodenal arcade (celiac + SMA), splenic branches
• "God put the pancreas in the back because he did not want surgeons messing with it" — retroperitoneal, hard to access

2. Acute pancreatitis (急性胰腺炎) (MUST KNOW)

1. Clinical (typical epigastric pain) 2. Serum amylase/lipase ≥3× upper limit (lipase more specific; amylase returns to normal in 3-5 days) 3. Imaging (CT) findings of pancreatitis

- Ranson criteria (at admission & 48 h) — 11 factors (age >55, WBC >16, glucose >11, LDH >350, AST >250, Ca <2.0, Hct fall >10%, BUN rise, PaO2 <60, base deficit >4, fluid sequestration >6 L) — ≥3 = severe - Glasgow (Imrie) score — similar (8 factors) - CT severity index (CTSI/Balthazar): A-E grade + necrosis % — necrosis >30% = severe - Organ failure (modified Marshall score) & CRP >150 at 48 h — predictors of severity

- Supportive care is the mainstay: aggressive IV fluids (crystalloid), analgesia, NPO initially, NG if vomiting/ileus, organ support (ICU: O2, vasopressors if shock), electrolyte correction (Ca, Mg, K) - Enteral nutrition early (within 24-48 h — nasojejunal preferred over parenteral; "if the gut works, use it") — reduces infection - No routine antibiotics for mild pancreatitis (prophylaxis doesn't help); antibiotics ONLY for infected necrosis/sepsis - ERCP: early (<72 h) if acute cholangitis or persistent biliary obstruction (gallstone pancreatitis); sphincterotomy + stone extraction - Gallstones: cholecystectomy during the same admission (after resolution) to prevent recurrence - Surgery (delayed, 3-4 weeks): for infected necrosis (step-up: percutaneous/endoscopic drainage → minimally invasive necrosectomy), complications (abscess, hemorrhage, bowel ischemia); open necrosectomy is high-mortality

- Local: acute peripancreatic fluid collection → pancreatic pseudocyst (4-6 weeks, walled-off; drain if symptomatic/infected/large), pancreatic necrosis (sterile vs infected — infected needs intervention), abscess, hemorrhage (erosion of the splenic artery — the classic), splenic vein thrombosis → left-sided (sinistral) portal HTN - Systemic: ARDS, AKI, DIC, MODS, hyperglycemia, hypocalcemia

• Definition: acute inflammation of the pancreas with autodigestion by activated enzymes
• Causes (MUST KNOW): gallstones (most common — 40-50%), alcohol (~25-30%), idiopathic; others: hypertriglyceridemia, ERCP, trauma, drugs (azathioprine, thiazides, steroids), hypercalcemia, infections (mumps), autoimmune, pancreas divisum
• Pathophysiology: premature activation of trypsin → autodigestion → inflammation, fat necrosis, hemorrhage → local complications (necrosis, abscess, pseudocyst) → SIRS → organ failure (ARDS, AKI, shock)
• Clinical: severe epigastric pain radiating to the back, relieved by leaning forward, nausea/vomiting; epigastric tenderness (peritonism in severe); fever, tachycardia, hypotension (severe); Cullen's sign (periumbilical bruising) & Grey-Turner's sign (flank bruising) = hemorrhagic/necrotizing (late, poor prognosis)
• Diagnosis (MUST KNOW — requires 2 of 3):
• Severity assessment (MUST KNOW):
• Imaging: CT with IV contrast (at 72 h for severity/necrosis — early CT underestimates); US (gallstones — cause); MRCP (CBD stones)
• Management (MUST KNOW):
• Complications (MUST KNOW):
• Mortality: mild <1-5%; severe with organ failure 20-50%

3. Chronic pancreatitis (慢性胰腺炎)

• Cause: alcohol (most common), hereditary, autoimmune, obstructive (stricture/stone), tropical; "burned-out" gland with fibrosis & calcification
• Clinical: chronic epigastric pain (the dominant symptom), malabsorption (steatorrhea, weight loss), diabetes (endocrine failure), pancreatic calcifications on imaging
• Diagnosis: CT (calcification, dilated duct, atrophy), MRCP/ERCP (duct changes — "chain of lakes"), fecal elastase (exocrine insufficiency)
• Treatment: pain control (analgesics, celiac plexus block), alcohol cessation, enzyme replacement (pancreatin — steatorrhea), insulin (diabetes); endoscopic therapy (stenting, ESWL for stones); surgery (pancreaticojejunostomy/Puestow, resection) for intractable pain or mass
• Differential of pain: exclude pancreatic cancer (ca 19-9, imaging, biopsy)

4. Pancreatic cancer (胰腺癌) (MUST KNOW)

- Head cancer: PAINLESS OBSTRUCTIVE JAUNDICE (dark urine, pale stools, pruritus) + Courvoisier's law (painless jaundice with a palpable, non-tender gallbladder — suggests malignant obstruction, not stones) — the classic - Weight loss, anorexia, epigastric/back pain (retroperitoneal invasion — late), new-onset diabetes, Trousseau's sign (migratory thrombophlebitis — paraneoplastic) - Body/tail: pain + weight loss (jaundice late) — presents later, worse prognosis

- CT pancreas protocol (triphasic): hypodense mass, duct dilation ("double duct sign" — dilated CBD & pancreatic duct), vascular involvement (staging: resectable vs borderline vs locally advanced vs metastatic), liver mets - CA19-9 (marker — monitoring, not screening); biopsy (EUS-FNA) for tissue if neoadjuvant/metastatic; staging laparoscopy (peritoneal mets) - MRCP/EUS for small/equivocal tumors; PET-CT for staging

- Resectable: surgical resection — pancreaticoduodenectomy (Whipple) for head tumors (remove head, duodenum, distal CBD, gallbladder, distal stomach ± pylorus — pylorus-preserving; + lymphadenectomy); distal pancreatectomy + splenectomy for body/tail - Adjuvant chemotherapy (FOLFIRINOX/gemcitabine-based) — improves survival; neoadjuvant chemo(± RT) increasingly used for borderline/resectable - Locally advanced/metastatic: chemotherapy (FOLFIRINOX, gemcitabine + nab-paclitaxel); palliative biliary stenting (ERCP), gastric bypass (duodenal obstruction), celiac plexus block (pain) - Radiotherapy: selected (borderline/unresectable)

- Tumor at the ampulla (adenocarcinoma of the ampulla/duodenum/CBD/pancreatic duct) - Earlier jaundice (obstructs the ampulla early) → diagnosed earlier → BETTER prognosis than pancreatic head cancer - Clinical: fluctuant jaundice, GI bleeding (ampullary ulceration — melena), anemia - Treatment: Whipple operation (same resection); better resectability & survival

• Most common: pancreatic ductal adenocarcinoma (PDAC) — head (60-70%), body/tail
• Risk factors: smoking, chronic pancreatitis, diabetes, family history, age >60; (H. pylori debate)
• Clinical:
• Diagnosis:
• Staging & resectability: resectable = no arterial involvement, clear venous; borderline = limited venous; unresectable = arterial involvement/mets
• Treatment (MUST KNOW):
• Prognosis: POOR — overall 5-year survival ~10% (all stages); resected + adjuvant ~20-30%; metastatic ~6-12 months — "the most lethal common cancer"
• Periampullary carcinoma (壶腹周围癌) — MUST KNOW:

High-Yield Points

• Acute pancreatitis: gallstones > alcohol > idiopathic; diagnosis = 2 of 3 (pain, amylase/lipase ≥3×, CT findings)
• Epigastric pain → back, relieved leaning forward; Cullen/Grey-Turner = hemorrhagic (late)
• Severity: Ranson (≥3 severe), Glasgow, CTSI (necrosis), organ failure; CT at 72 h
• Treatment: fluids + analgesia + organ support + early ENTERAL nutrition; no routine antibiotics; ERCP if cholangitis/biliary obstruction; cholecystectomy same admission (gallstones)
• Infected necrosis: step-up approach (drainage → necrosectomy), delayed 3-4 weeks
• Pseudocyst: 4-6 weeks, walled-off; drain if symptomatic/infected
• Pancreatic cancer: painless jaundice + Courvoisier (palpable gallbladder); CA19-9; CT protocol; double duct sign
• Whipple (pancreaticoduodenectomy) for head; distal pancreatectomy for body/tail; adjuvant chemo
• Prognosis poor; periampullary = earlier jaundice, better prognosis
• Trousseau's sign (migratory thrombophlebitis) — paraneoplastic

Topic Summary

Acute pancreatitis: gallstones (most common), alcohol, idiopathic; diagnosis = 2 of 3 (typical pain, enzymes ≥3×, CT findings); severity by Ranson/Glasgow/CTSI/organ failure. Treatment: aggressive fluids, analgesia, organ support, early enteral nutrition, no routine antibiotics; ERCP for cholangitis/biliary obstruction; cholecystectomy same admission; infected necrosis → delayed step-up intervention. Complications: pseudocyst (4-6 weeks, walled-off), necrosis, abscess, hemorrhage (splenic artery), systemic organ failure. Chronic pancreatitis: alcohol, pain + steatorrhea + diabetes; enzymes + pain control ± surgery. Pancreatic cancer: painless obstructive jaundice + Courvoisier's law; CA19-9; CT protocol (double duct sign); Whipple for resectable head tumors + adjuvant chemo; poor prognosis; periampullary tumors present earlier with jaundice and do better.