Pancreatic Pseudocyst

l   A fluid collection contained within a well-defined capsule of fibrous or granulation tissue or a combination of both

l   Does not possess an epithelial lining

l   Persists > 4 weeks

l   May develop in the setting of acute or chronic pancreatitis

l    Most common cystic lesions of the pancreas, accounting for 75-80% of such masses

l    Location

l   Lesser peritoneal sac in proximity to the pancreas

l   Large pseudocysts can extend into the paracolic gutters, pelvis, mediastinum, neck or scrotum

l   May be loculated

Composition

l   Thick fibrous capsule – not a true epithelial lining

l   Pseudocyst fluid

l   Similar electrolyte concentrations to plasma

l   High concentration of amylase, lipase, and enterokinases such as trypsin

Pathophysiology

l   Pancreatic ductal disruption 2° to

l   Acute pancreatitis – Necrosis

l   Chronic pancreatitis – Elevated pancreatic duct pressures from strictures or ductal calculi

l   Trauma

l   Ductal obstruction and pancreatic neoplasms

Presentation

l   Symptoms

l   Abdominal pain > 3 weeks (80 – 90%)

l   Nausea / vomiting

l   Early satiety

l   Bloating, indigestion

l   Signs

l   Tenderness

l   Abdominal fullness

Diagnosis

l   CT scan

l   MRI / MRCP

l   Ultrasonography

l   Endoscopic Ultrasonography (EUS)

l   ERCP

 

Pseudocyst compressing the stomach wall posteriorly

EUS showing pseudocyst

Complications

l    Infection

l   S/S – Fever, worsening abd pain, systemic signs of sepsis

l   CT – Thickening of fibrous wall or air within the cavity

l    GI obstruction

l    Perforation

l    Hemorrhage

l    Thrombosis – SV (most common)

l    Pseudoaneurysm formation – Splenic artery (most common), GDA, PDA

Treatment

l   Initial

l   NPO

l   TPN

l   Octreotide

l   Antibiotics if infected

l   1/3 – 1/2 resolve spontaneously

Intervention

l   Indications for drainage

l   Presence of symptoms  (> 6 wks)

l   Enlargement of pseudocyst ( > 6 cm)

l   Complications

l   Suspicion of malignancy

l   Intervention

l   Percutaneous drainage

l   Endoscopic drainage

l   Surgical drainage

Percutaneous Drainage

l    Continuous drainage until output < 50 ml/day + amylase activity ↓

l   Failure rate 16%

l   Recurrence rates 7%

l    Complications

l   Conversion into an infected pseudocyst (10%)

l   Catheter-site cellulitis

l   Damage to adjacent organs

l   Pancreatico-cutaneous fistula

l   GI hemorrhage

Endoscopic Management

l     Indications

l   Mature cyst wall < 1 cm thick

l   Adherent to the duodenum or posterior gastric wall

l   Previous abd surgery or significant comorbidities

l     Contraindications

l   Bleeding dyscrasias

l   Gastric varices

l   Acute inflammatory changes that may prevent cyst from adhering to the enteric wall

l   CT findings

l  Thick debris

l  Multiloculated pseudocysts

Endoscopic Drainage

l   Transenteric drainage

l   Cystogastrostomy

l   Cystoduodenostomy

l   Transpapillary drainage

l   40-70% of pseudocysts communicate with pancreatic duct

l   ERCP with sphincterotomy, balloon dilatation of pancreatic duct strictures, and stent placement beyond strictures

Surgical Options

l    Excision

l   Tail of gland & a/w proximal strictures – distal pancreatectomy & splenectomy

l   Head of gland with strictures of pancreatic or bile ducts – pancreaticoduodenectomy

l    External drainage

l    Internal drainage

l   Cystogastrostomy

l   Cystojejunostomy

l   Permanent resolution confirmed in b/w 91%–97% of patients*

l   Cystoduodenostomy

l   Can be complicated by duodenal fistula and bleeding at anastomotic site

Laparoscopic Management

l   The interface b/w the cyst and the enteric lumen must be ≥ 5 cm for adequate drainage

l   Approaches

l   Pancreatitis 2° to biliary etiology ® extraluminal approach w/ concurrent laparoscopic cholecystectomy

l   Non-biliary origin ® intraluminal (combined laparoscopic/endoscopic) approach

References

Swayer et al. Pancreatic pseudocyst.  http://www.emedicine.com/radio/topic576.htm

Bradley III et al. A clinically based classification system for acute pancreatitis: summary of the International Symposium on Acute Pancreatitis, Arch Surg. 1993;128:586-590

Cohen et al. Pancreatic pseudocyst. In: Cameron JL, ed. Current Surgical Therapy. 7th ed.; 2001: 543-7

Gumaste et al: Pancreatic pseudocyst. Gastroenterologist 1996 Mar; 4(1): 33-43

Nealon et al, Analysis of surgical success in preventing recurrent acute exacerbations in chronic pancreatitis. Ann Surg. 2001;233:793–800

Nealon et al. Surgical management of complications associated with percutaneous and/or endoscopic management of pseudocyst of the pancreas. Ann Surg. 2005 Jun;241(6):948-57