PANCREATIC DUCTAL ANOMALIESDr. Mathews J Chooracken

23.7.2009

Pancreatic organogenesis Classification Pancreatic divisum Annular pancreas Anomalous pancreaticobiliary union conclusion

PANCREATIC ORGANOGENESIS

NORMAL PANCREATIC DUCT

PANCREAS DIVISUM

most common congenital pancreatic ductal anatomic variant

dominant dorsal duct syndrome causative lesion is relative stenosis of the minor papilla

rather than pancreas divisum per se

failure of the dorsal and ventral pancreatic anlage to fuse

classic pancreas divisum anatomy small ventral duct which drains through the major

papilla larger dorsal duct which drains through the minor

papilla no communication exists between the dorsal and

ventral pancreatic ducts

EPIDEMIOLOGY

4–14% of the population autopsy series 3–8% at ERCP 9% at MRCP

Lehman GA, Sherman S Gastrointest Endosc Clin N Am 1998

INDIAN DATA

4.5% male and 6% female cadavers

Prevalence of 3.7% on ERCP, 9.2% of patients presented with pancreatitis

higher frequency of SPINK1 gene mutation compared with healthy controls

Sahni D, et al. Trop Gastroenterol. 2001 Oct-Dec;22(4):197-201

Dhar A, et al.  Indian J Gastroenterol. 1996 Jan;15(1):7-9

Garg PK, et al. J Clin Gastroenterol. 2009 Jul 10

LAKESHORE DATA ERCP’s -590 since June 2006 Pancreas divisum – 12 Incomplete divisum -1 Sphincterotomy -12 Minor papilla stenting -7 Ductal Stricture -2 Chronic pancreatitis - 4

TYPES Complete Incomplete

small branch of the ventral duct communicates with the dorsal duct

15 % of cases of pancreas divisum modest to full visualization of the dorsal duct may occur

with vigorous major papillary contrast injection clinical implications are the same as for classic (or

complete) pancreas divisum

"reverse" divisum (inverted) when the accessory duct of Santorini does not connect

with the genu of the main pancreatic duct physiologic significance : overflow ‘valve’ to the main

ductal system is absent gallstone impacted at the major papilla will likely cause

more severe pancreatitis

OTHER PANCREATOBILIARY ABNORMALITIES

annular pancreas elevated sphincter of Oddi basal pressures partial agenesis of the dorsal pancreas ? increased incidence of cholangiocarcinoma

and ampullary carcinoma

CLINICAL FEATURES

< 5 % of patients develop pancreatic symptoms.

? Cause of pancreatitis some studies have found that the incidence of pancreas

divisum is the same in patients with and without pancreatitis

symptoms occur infrequently in patients with this anomaly

60 % of patients with pancreas divisum and otherwise unexplained abdominal pain had relief of the pain after surgical sphincteroplasty

In patients with recurrent acute pancreatitis, treatment by either surgical or endoscopic papillotomy of the minor papilla resulted in relief from further attacks of acute pancreatitis by 80 percent

Lehman GA, Sherman S Gastrointest Endosc Clin N Am 1995

Delhaye M, Gastroenterology 1985 Nov;89(5):951-8.

CLINICAL SETTING

Coincidental finding On routine ERCP May be ignored

Minimal symptoms Can be managed conservatively ? Aggressive therapy to prevent progression

Pancreatitis Aggressive management

DIAGNOSIS

Gold standard- ERCP short and thin pancreatic ventral duct at the major

papilla (acinarization of the parenychma) filling of the dorsal duct at the minor papilla draining

pancreas from the tail to the anterior part of the head NO connection to the ventral duct

Suspect pancreas divisum if easy selective cannulation of the bile duct and

inability to enter the pancreatic duct failure of injected contrast in the pancreas to

flow past the head inability to pass a guidewire through the major

papilla into the pancreas

Minor papilla cannulation is dificult in 1/3rd of cases

Intravenous secretin Spray methylene blue on the surface of minor papilla

MRCP Dorsal pancreatic duct has a constant caliber crosses the common bile duct anteriorly separated from a smaller ventral duct

equivalent to ERCP Esp. If secretin stimulated MRCP is used

Secretin acts as a hydrographic endogenous contrast agent

Matos C, Metens T, Deviere J, Delhaye M, Gastrointest Endosc 2001;53:728-33

Endoscopic ultrasound If the ventral duct can be traced from the major

papilla through the body and the tail, PD usually can be excluded

Sahai AV. Gastrointest Endosc 2002

Assessment of stenosis of minor papillae measurement of the emptying time of the dorsal duct after

pancreatography- not standardised manometric studies - increase in the pancreatic dorsal duct

pressure are of limited usefulness- normal values not defined US- secretin test- poor reproducibility, inability to see MPD in

obesity, due to intestinal gas etc. S-MRCP- persistent dilatation of the main pancreatic duct

greater than 3 mm at 10 minutes after secretin injection abnormal response at S-MRCP did not significantly differ

between patients with or without PD

Matos C, Metens T, Deviere J, Delhaye M, Gastrointest Endosc 2001;53:728-33

Presence of morphological changes confined to dorsal pancreatic duct- suggestive of pancreas divisum

However, studies have demonstrated changes in ventral duct in patients with PD and chronic pancreatitis

Eisendrath P, et al. Prevalence and clinical evolution of isolated ventral pancreatitis in alcoholic chronic pancreatitis. Gastrointest Endosc 2000; 51:45-50.

Coleman SD, Eisen GM, Troughton AB, CottonPB. Endoscopic treatment in pancreas divisum. Am J Gastroenterol 1994; 89:1152-4

MANAGEMENT

Attempt to improve the pancreatic outflow through the minor papilla

selection criteria who might benefit from therapy is not clearly defined

However, results are better when the indication is that of recurrent acute pancreatitis as compared to that used for patients with pain alone or chronic pancreatitis

Endotherapy/ surgical options

Surgical Transduodenal sphincteroplasty of the minor

papilla with cholecystectomy and major papilla sphincteroplasty

Results difficult to compare

Prospective trial (largest surgical trial) 88 patients Sphincteroplasty Mean follow-up: 29 months 74% of patients with acute recurrent

pancreatitis had good response compared to 34% with pain only

Restenosis rate : 8% Patients with stenotic papilla did better (85%)

suggests a predictive role of secretin testing

Warshaw AL, Et al. Evaluation and treatment of the dominant dorsal duct Syndrome . Am J Surg1990, 159:59–64

ENDOSCOPIC MANAGEMENT

dilation, sphincterotomy, stenting Balloon dilation reported a high rate of

pancreatitis and is not recommended Sphincterotomy

In 5 series (83 patients) who were studied from 1984 to 1993,

74% of the patients with recurrent acute pancreatitis improved as compared to 26% of patients with pain alone and 46% of patients with chronic pancreatitis

High restenosis rate- upto 20% Hence stenting was advocated

A prospective, randomized trial compared long-term dorsal duct stenting to continued

conservative therapy 19 patients with pancreas divisum with recurrent

pancreatitis The stents (3 to 7 cm long with multiple side-holes)

were exchanged every three to four months and were left in place for one year.

The stented patients had a much higher rate of improvement (90 versus 11 percent) due to statistically significantly reductions in hospitalizations, emergency department visits, and pancreatitis episodes.

These benefits generally persisted over a mean 24-month follow-up period after stent removal. Ertan A, Gastrointest

Endosc 2000 Jul;52(1):9-14.

prolonged stent therapy remains largely experimental and is not generally recommended. prolonged pancreatic stenting is associated with

stent occlusion or migration, pancreatitis, pancreatic duct perforation, and pseudocyst formation

induction of ductal and parenchymal changes indicating or simulating chronic pancreatitis

Gastrointest Endosc 1996 Sep;44(3):276-82.

ANNULAR PANCREAS

characterized by a ring of pancreatic tissue surrounding the descending portion of the duodenum.

1 in 20,000 Only case reports from India

PATHOGENESIS

Baldwin’s hypothesis formation of the ring results from hypertrophy or

failure of regression of the left portion of a paired ventral bud

Lecco’s theory adhesion of the free end of a single ventral

pancreas to the duodenal wall

ventral duct generally courses posteriorly to join the main duct on the left.

OTHER DISEASE ASSOCIATIONS

intestinal atresias, malrotation, Tracheoesophageal fistula cardiac defects. Down’s syndrome

CLINICAL FEATURES

two thirds of patients remain asymptomatic for life

one half of patients become symptomatic at birth or during the first year of life with signs of duodenal obstruction

Adults may present with abdominal pain, nausea postprandial fullness, vomiting, upper GI bleeding (from peptic ulceration), acute or chronic pancreatitis and rarely biliary obstruction

Some series have suggested that patients who present with obstructive jaundice have an underlying periampullary malignancy

DIAGNOSIS

Infants: x-ray abdomen shows double bubble sign

In adults: CT Abdomen ERCP: If CT abdomen is equivocal

TREATMENT

preferred surgical approach bypass surgery of the annulus,

duodenoduodenostomy, gastrojejunostomy, or a duodenojejunostomy.

Resection of the annulus should be avoided it is associated with complications such as pancreatitis,

pancreatic fistula formation, and incomplete relief of obstruction

In patients presenting with obstructive jaundice, a thorough investigation must be undertaken to evaluate for associated periampullary malignancy.

PROGNOSIS

40% mortality in infants because of associated congenital anomalies

ANOMALOUS PANCREATICOBILIARY UNION (APBU)

confluence of the common bile duct and the pancreatic duct is outside the duodenal wall, with a common channel measuring more than 15 mm

1.5 to 3.2% in various series possible cause of choledochal cysts, bile duct

and gallbladder carcinoma, and recurrent pancreatitis

DIAGNOSIS

ERCP high risk of pancreatitis

in the presence of a common channel, duct opacification often requires repetitive injections of the pancreatic duct

MRCP Detected ABPU in 82% of cases provided that a

common channel 15 mm or longer

Endoscopic ultrasonography detect APBU in 88% of cases if a common channel of

12 mm or longer is observed

Sugiyama M,. Gastrointest Endosc 1997;45:261-7

TREATMENT

APBU with a congenital choledochal cyst excision of the extrahepatic bile duct and gallbladder

with Roux-en-Y reconstruction of the biliary tree prophylactic cholecystectomy is recommended

because of the higher risk of gallbladder carcinoma development

CONCLUSIONS

Pancreas divisum is the commonest ductal anomaly

5-10% of prevalence <5% are symptomatic Can be complete, incomplete, reverse

divisum Diagnosis is by ERCP S-MRCP may be equivalent to ERCP

If the patient has acute recurrent pancreatits, endotherapy and stenting is most useful

Long term stenting is not recommended

Annular pancreas Ring of pancreatic tissue around D2 Majority are asymptomatic 50% of patients presents in infancy with

duodenal obstruction Diagnosis is by imaging modalities like CT

abdomen Annular bypass is the surgery of choice Infants have higher mortality due to associated

abnormalities

Anomalous pancreaticobiliary union CBD joins PD outside the duodenum Common channel has 15 mm in length Associated with choledochal cyst,

cholangiocarcinoma gall bladder carcinoma and recurrent pancreatitis

Diagnosis is by ERCP, MRCP, EUS Surgery is indicated if there is associated

choledochal cyst Prophylactic cholecystectomy in patients

undergoing surgery as there is high risk for gall bladder carcinoma