Michels classified the variation in the relationship between the common bile and pancreatic ducts at the ampulla of Vater.
Features:
(1) junction between the common bile and pancreatic ducts
(2) distance between any junction of the ducts and the opening into the duodenum
(3) number of separate openings
|
Junction Between Ducts |
Distance from Junction to Opening |
Type |
|
present some distance from the opening |
variable (up to 14 mm) |
1 |
|
present right at the opening into the duodenum (single opening) |
none or extremely short |
2 |
|
none (2 separate openings with intact septum between) |
NA |
3 |
In Type 1 a dilation of the common channel tends to be seen if the distance between junction and opening is >= 5 mm.
|
Type |
Relative Frequency |
|
1 |
85% |
|
2 |
5% |
|
3 |
9% |
|
Type |
Associated Findings |
|
1 |
obstruction distal to junction will result in (1) dilatation of both the common bile and pancreatic ducts and (2) potential flow of bile into pancreas |
|
2 |
an obstruction at the opening can dilate both ducts but flow of bile into the pancreatic duct is unlikely; an obstruction in the distal portion of one duct may not result in obstruction of the other |
|
3 |
obstruction of one or the other duct may not result in obstruction of the other duct |
Specialty: Gastroenterology
ICD-10: ,
