The bile duct is some 6–8 cm long, and normally up to 8 mm in diameter.[4]
Its proximal supraduodenal part is situated within the free edge of the lesser omentum. Its middle retroduodenal part is oriented inferiorly and right-ward, and is situated posterior to the first part of the duodenum, and anterior to the inferior vena cava. Its distal paraduodenal part is oriented still more right-ward, is accommodated by a groove upon (sometimes a channel within) the posterior aspect of the head of the pancreas, and is situated anterior to the right renal vein.[4]
The distal extremity of the bile duct invariably features its own sphincteric muscle (the pancreatic duct and the hepatopancreatic ampulla usually possess sphincters of their own to allow the flow of pancreatic juice to be regulated independently, however, these two can be absent).[4]
Several problems can arise within the common bile duct, usually related to its obstruction. Opinions vary slightly on the maximum calibre of a normal CBD, but 6mm is one accepted upper limit of normal [5] with a further 1mm diameter allowed for each decade over 60 years.
Tumours in the head of the pancreas may come to obstruct the distal bile duct.[4]
If obstructed by a gallstone, a condition called choledocholithiasis can result.[7] In this obstructed state, the duct is especially vulnerable to an infection called ascending cholangitis. One form of treatment is a cholecystenterostomy. Rare deformities of the common bile duct are cystic dilations (4 cm), choledochoceles (cystic dilation of the ampula of Vater (3–8 cm)), and biliary atresia.
^Agabegi, Steven S.; Agabegi, Elizabeth D. (23 August 2012). Step-Up to Medicine. Lippincott Williams & Wilkins. p. 136. ISBN9781609133603.
^Standring S, Borley NR, eds. (2008). Gray's anatomy : the anatomical basis of clinical practice. Brown JL, Moore LA (40th ed.). London: Churchill Livingstone. pp. 1163, 1177, 1185–6. ISBN978-0-8089-2371-8.
^Feng, B; Song, Q (1995). "Does the common bile duct dilate after cholecystectomy? Sonographic evaluation in 234 patients". American Journal of Roentgenology. 165 (4): 859–861. doi:10.2214/ajr.165.4.7676981. ISSN0361-803X. PMID7676981.
^Bateson, Malcolm C., ed. (1986). Gallstone Disease and its Management. Dordrecht: Springer Netherlands. p. Epidemiology (chapter). ISBN9400941730.
Miederer, S.; Lindstaedt, H.; Siedek, M.; Franken, Th. (1978).『Endoskopische transpapilläre Spaltung einer Choledochocele』[Endoscopic transpapillary Splitting of a choledochocele]. Deutsche Medizinische Wochenschrift (in German). 103 (5): 216–219. doi:10.1055/s-0028-1104409. PMID631041.
