Pancreas—Pancreatic Pseudocyst
Concept
A walled-off collection of pancreatic enzymes and inflam- matory fluid typically in the lesser sac (with the bound- aries formed by the lesser sac) or within the pancreas itself that is bounded by a nonepithelialized wall of fibrotic tis- sue. Can develop symptoms related to size (obstruction, pain) or erosion into other structures (bleeding).
Way Question May be Asked?
“A 48 y/o male with history of alcohol abuse and pancreati- tis presents to ER with abdominal pain and work-up reveals a 4 cm pancreatic pseudocyst.” Question could be abdomi- nal pain in a patient with a history of pancreatitis, or could be given the formation of a pseudocyst after an initial bout of pancreatitis with the patient still in the hospital.
How to Answer?
Complete H+P
Weight loss Vomiting Abdominal mass Trauma
Alcoholism
Bouts of acute or chronic pancreatitis Palpable mass
Diagnostic Tests
Appropriate laboratory tests (amylase, WBC) U/S good for screening
CT gold standard
Be complete, but don’t dwell on these as the examiner is trying to get to your management here:
Differentiate pseudocysts based on size and symptoms.
Non-symptomatic less than 4 cm in size should be fol- lowed by serial U/S/CT scans—can continue to follow as long as decreasing in size.
Be prepared for pseudocyst to: rupture, obstruct, bleed, get secondarily infected, or increase in size.
Cysts with duration greater than 6 weeks, enlarging on CT, greater than 4 cm, or are associated with chronic pancreati- tis are unlikely to resolve without operative intervention
6 cm or greater pseudocysts or symptomatic ones should undergo interventional treatment:
TREATMENT
(1) ERCP to see if communicates;
(a) if doesn’t, can consider CT aspiration (~40%
success rate) or leaving a catheter in cyst cavity (these options will fail or the cyst will get secondarily infected)
(b) if does, and symptomatic or larger than 4 cm →surgical drainage
(2) Choices for internal drainage (remember cyst wall takes about 6 weeks to mature):
(a) cystgastrostomy (anterior gastrostomy, palpa- tion and needle aspiration to find cyst in back wall of stomach and then open cyst, send part of wall for bx, and suture posterior wall of stomach to mature cyst wall, opening should be 5 cm, use interrupted absorbable sutures) (b) cystojejunostomy (use Roux loop when cyst is not
adherent to posterior wall of stomach (can check by opening gastrocolic omentum and seeing if there is plane b/w posterior stomach and cyst) or multiple cysts (using side-to-side anastomosis) (c) cystoduodenostomy (if in head of pancreas close
to duodenum, Kocher maneuver to check, 3 cm opening into first or third portion of the duode- num, transduodenal approach)
88
Part 2.qxd 10/19/05 2:52 AM Page 88
(d) distal pancreatectomy (option if pseudocyst in pancreatic tail or has eroded into surrounding structures)
(3) External drainage only for (a) infected pseudocysts
(b) unstable pt with free rupture or bleeding (4) bleeding in pt with a pseudocyst can be from:
(a) bleeding into the bowel from erosion into bowel wall
(b) bleeding from gastric varices (splenectomy treatment of choice here as varices form secondary to splenic vein thrombosis)
(c) bleeding into the cyst (erosion into one of the pancreatic vessels)
(d) bleeding from a ruptured pseudoaneurysm (usually splenic artery)
(e) bleeding may occur into cyst, into bowel, or free into peritoneal cavity
Angiogram helpful here if pt stable enough, otherwise, laparotomy, ligate offending vessels, open cyst, pack and return or go to angiogram as necessary
Common Curveballs
There will be multiple cysts
Try to get you to change your management strategy so the size may change during the questioning from 4 cm to 8 cm
Try to get you to operate before a mature wall has formed Pseudocyst will rupture into thoracic cavity (pancreatic
hydrothorax)
Your first choice of internal drainage will not be an option (prior surgery, . . .)
The pt with known pseudocyst will develop bleeding into the pseudocyst and present in shock (see above
for DDx; angiogram to embolize bleeding vessel, otherwise ex lap, ligation splenic or gastroduodenal, then open and pack cyst and ligate bleeders within cyst wall)
The pseudocyst will get infected if you try to aspirate it If you leave a drainage catheter for non-communicating
cyst, the pt will get a pancreatic fistula
GI doctor will not be available for ERCP or endoscopic cystgastrostomy or endoscopic cystgastrostomy will result in free perforation/bleeding at the anastomotic site
Biopsy of the wall will reveal malignancy Pt will have pancreatitis flare after ERCP
Pseudocyst will actually be cystic neoplasm by intra-op frozen section biopsy (change of scenario)
Pt that you decide to follow will develop complication from pseudocyst such as:
cyst rupture—pancreatic ascites
infection (fever, inc. WBC, inc. abd pain →open surgical drainage)
bleeding (hemorrhagic shock) duodenal obstruction
pseudoaneurysm splenic vein thrombosis
Strikeouts
Forgetting to biopsy the wall of the pseudocyst Not waiting for wall to mature
Not obtaining a CT scan
Not knowing how to perform internal drainage proce- dure
Not getting ERCP pre-op to determine if communi- cates with pancreatic duct
Taking pt with bleeding from pseudocyst to OR rather than angiogram to embolize offending vessel While has been performed by several authors, don’t
mention laparoscopic cystogastrostomies
Strikeouts 89
Part 2.qxd 10/19/05 2:52 AM Page 89
