Pancreas: Pancreatic Pseudocyst

Pancreatic Pseudocyst

General

  • Definition: Collection of Pancreatic Fluid Outside of the Ducts (No Epithelial Lining)
    • Fibrotic Capsule Forms Over 4-8 Weeks, Composed of Collagen and Granulation Tissue
  • Most Common Cause: Chronic Pancreatitis
  • Poor Predictors: ≥ 6 weeks or ≥ 6 cm Mn

Complications

  • Infection
  • Splenic Vein Thrombosis
  • Pseudoaneurysm

Diagnosis/Definitions

  • CT: Based on Revised Atlanta Classification
  • Revised Atlanta Classification:
    • Acute Pancreatic Fluid Collection
      • ≤ 4 Weeks
      • Homogenous Fluid Density – No Solid Component
      • No Defined Wall
      • Extrapancreatic & Confined by Normal Fascial Planes (None Intrapancreatic)
    • Pancreatic Pseudocyst
      • > 4 Weeks
      • Homogenous Fluid Density
      • Well Defined Wall

Pancreatic Pseudocyst on CT 1

Treatment

  • Asymptomatic & < 5-6 cm: Conservative
  • Symptomatic or > 5-6 cm: Internal Drainage
    • Preferred Route: Endoscopic Cystogastrostomy or Cystoduodenostomy
      • Requirements:
        • Mature Cyst Wall (Most Important Prognosis Factor)
        • Pseudocyst Wall Must be Adherent to Stomach or Duodenum
      • External Percutaneous Drain Have Higher Risk of Complications & Pancreaticocutaneous Fistula
    • If Unable: Roux-en-Y Cystojejunostomy
      • Use Full-Thickness Absorbable Sutures (Interrupted Closely Spaced or Running)
      • Always Send Bx
    • Absolute Contraindication: Pseudoaneurysm (Embolize First)
    • Consider Endoscopic Pancreatic Duct Stent if Pseudocyst Communicates to the Pancreatic Duct (Internal Pancreatic Fistula)
      • Fistula May Present as Recurrent Pseudocyst After Prior Drainage
  • Cystic Neoplasia or Technically Unable to Drain in the Uncinate Process: Requires Resection
  • Ruptured or Unstable: Percutaneous/External Drainage
    • Rarely Used – High Morbidity & Risk for Pancreatic Fistula

Endoscopic Cystogastrostomy 2

Mnemonics

Poor Predictors of Pseudocyst

  • #6 – The Number of the Pancreas (Used in Other Mnemonics: PNET and Chronic Pancreatitis)
  • Pancreas Looks Like a #6
  • Poor Predictors: > 6 weeks or > 6 cm

#6 – The Number of the Pancreas

References

  1. Tuboku-Metzger VR, Seenath MM, Tan LC. Peritonitis secondary to traumatic duodenal laceration in the presence of a large pancreatic pseudocyst: a case report. J Med Case Rep. 2011 Oct 26;5:528. (License: CC BY-2.0)
  2. Anderloni A, Attili F, Carrara S, Galasso D, Di Leo M, Costamagna G, Repici A, Kunda R, Larghi A. Intra-channel stent release technique for fluoroless endoscopic ultrasound-guided lumen-apposing metal stent placement: changing the paradigm. Endosc Int Open. 2017 Jan;5(1):E25-E29.(License: CC BY-NC-ND-4.0)