Graduation Date

Spring 5-6-2023

Document Type


Degree Name

Master of Science (MS)


Medical Anatomy

First Advisor

Travis McCumber, Ph.D.

Second Advisor

Shaheed Merani, M.D., Ph.D.

Third Advisor

Ethan Snow, Ph.D.

Fourth Advisor

Keely Cassidy, Ph.D.


Continued occurrence of cholelithiasis, gallstones, commonly results in cholecystectomy, removal of the gallbladder. Having a comprehensive anatomical, histological, and physiological knowledge of the biliary apparatus is imperative in clinical medicine today. Additionally, the functionality of cystic duct (CD) Heister valves (HV) has been speculatory since being reported in 1732. This study summarizes the morphology, orientation, and variability of the gross biliary system and provides data to help justify HV functionality.

Cadaveric dissection was utilized for gross observation and analysis of the biliary system. The angulation of the CD was found primarily as an acute angle; however, obtuse angulation could be related to the presence and amount of adipose in the surrounding area and may need consideration during the surgical approach. Overall, ex vivo lengths of the common hepatic duct (CHD), CD, and common bile duct (CBD) were consistent with current literature which is beneficial for the validity of use of cadaveric tissue and correlation analysis associated with duct length. Interestingly, this study, of low sample size, observed two variants in CD anatomy as well as an associated arterial variation.

Subsequently, histological analysis of the muscularis externa demonstrated a lack of uniform HV distributed throughout the CD with muscularis externa being more robust proximally. No correlation was found between CD length and HV. While the proximal CD and its lumen may be reliant on HV for support and bile regulation, the entirety of the CD, even those of greater length, does not appear to be impacted by HV.


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