Cystic Duct Variations in Adult Population; A Magnetic Resonance Based Cholangiopancreaticography at a Tertiary Care Referral Hospital

Objective: To demonstrate the imaging and anatomical features of cystic duct variants on Magnetic resonance cholangiopancreaticography and document prevalence in urban population. Study Design: Retrospective observational study. Place and Duration of Study: Department of Radiology, Liaquat National Hospital Karachi, from January 2021 to December 2022. Methodology: Magnetic resonance cholangiopancreaticography (MRCP) was performed in a total of 152 cases for various indications for example cholelithiasis, choledocholithiasis, biliary tracr obstruction, acute cholecystitis,chronic pancreatitis and pancreatic divisum, A phased array body coil and departmental protocols were used for the examinations, which produced heavily T2 weighted sequences including FRFSE (fast recovery fast spin echo) coronal oblique 3D images. Through multiplanar reconstruction, reformatting and maximum intensity projections were done for acquired images to optimize ductal visualization. PACS (picture archiving and communication system) was used for the evaluation of MRCP images. The ductal course, length, and insertion of the cystic duct were recorded. Descriptive statistics were calculated using SPSS. Chi-Square test was applied considering p-value ≤0.05 as significant. Results: The mean age was 34.49±7.78 years. For the insertion of the cystic on bile duct, Right Lateral Insertion was 70.4%, Spiral Course with Medial Insertion was 3.3%, Low lateral insertion was 6.6%, Low Medial insertion was 5.3%, High Insertion was 3.3%, Anterior Insertion was 1.3%, Posterior Insertion was 7.9%. For the course and length or cystic duct, parallel Course was 7.2%, Short length of cystic duct was 17.1%. In others variants, Cystic duct joining right hepatic duct was 0.7%, and no Right Posterior sectorial hepatic duct draining into cystic duct was observed. On the other hand, there is no significant difference between age or sex and a specific anatomical variation in the cystic duct, p > 0.05. Conclusion: Among the existing anatomical variants in the cystic duct in this adult population, where the lateral insertion is the most common form, up to 70% of the cases, it should not be overlooked that approximately one of every five patients may have a short cyst which can predispose to bile duct injury at the time of a cholecystectomy if adequate care is not taken.