| کلیدواژههای انگلیسی مقاله |
Cystic duct, Bile ducts, Extrahepatic, Cholangiopancreatography, Magnetic resonance, Radiography, What&,rsquo s Known Anatomic variations are seen in the course and the insertion point of the cystic duct. The three common and clinically essential variants are low insertions, medial insertion, and parallel cystic duct course. Taking these variants into consideration will reduce the complications subsequent to surgical, endoscopic, or percutaneous procedures. What&,rsquo s New Less invasive diagnostic and therapeutic methods are currently developing for hepatobiliary and pancreatic diseases, requiring familiarity with these variants for safe and successful outcomes. We observed less low insertion, medial insertion, and parallel course of the cystic duct. However, a higher frequency of high insertion was noted in the population. IntroductionDifferent anatomic variations are observed in the cystic duct course and insertion point. 1, - 3, Identification of the normal anatomy and variations of the cystic duct (CD) is essential before the hepatobiliary surgery or endoscopic and percutaneous interventions, such as endoscopic retrograde cholangiopancreatography (ERCP) for the prevention of iatrogenic complications. 3, - 6, Different modalities exist for the demonstration of biliary anatomy. Ultrasound is the first choice for evaluating intrahepatic bile ducts and common bile ducts. However, the non-dilated cystic duct cannot be delineated in sonography. The delineation of CD in CT scan needs intravenous biliary contrast agent injection. 3, Intraoperative cholangiography is invasive and inconclusive in several cases. 7, Magnetic resonance cholangiopancreatography (MRCP) is the modality of choice for evaluating the normal anatomy of intrahepatic and extrahepatic bile ducts and CD being non-invasive, radiation-free, and without need for contrast injection and anesthesia. 8, , 9, The cystic duct originates from the gall bladder and drains into the common hepatic duct to form a common bile duct with a length of about 2-4 cm and a diameter of 1-5 mm. 6, The variability of CD insertion site to the extrahepatic bile duct (EHBD) is observed. However, it usually joins it at the middle part (between the confluence and the ampulla of Vater) from the right lateral aspect.Different variations of the CD insertion point are demonstrated. 10, , 11, The most important ones are as follows, the low insertion of CD, the parallel course of CD, anterior or posterior spiral course with medial insertion, absent or short CD, and drainage to the right hepatic duct (RHD), left hepatic duct (LHD), or their confluence.Shiraz has been the referral center for liver transplantation, surgical, and endoscopic biliary interventions. Taking the cystic duct patterns into consideration is extremely helpful for successful and safe performation of these procedures. To the best of our knowledge, no survey has been conducted for the evaluation of these expected variations in the Iranian population. This study aims to determine the prevalence of cystic duct variations in the population of South of Iran. Materials and MethodsThis retrospective cross-sectional study was performed with the approval of the Shiraz University of Medical Sciences Research and Ethics Committee (IR.SUMS.Med.Rec.1395.s174). The MRCP of all cases referred to Shiraz Faraparto Medical Imaging and Interventional Radiology Center from October 2017 to October 2018 with different indications were included in the study. Written informed consent was obtained from all individuals.Moreover, 350 images (MRCP) were included and the CD insertion site could be evaluated in 290 cases. Sixty exams were excluded due to the previous cholecystectomy, severe ascites, liver transplant, and the overlapping of structures. Patients fasted for about six hours before the study. No anti-peristaltic agent was administered. MRCP was performed on a 1.5 Tesla MRI unit (Siemens, Erlangen, Germany) utilizing a phased array body coil.The preferred sequences for the best information on the biliary tree&,rsquo s anatomy were as follows, axial 2D breath-hold half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence, 3D respiratory-triggered heavily T2-weighted fast spin-echo (FSE) sequence in the coronal oblique plane, and coronal maximum intensity projection (MIP) reformat.MRCP images were reviewed in a picture archiving communication system (PACS) by a gastroenterologist and expert radiologist. Demographic data, the course, and the insertion site of the cystic duct were recorded in the data gathering form. The insertion site was classified as high, mid, or low, if the cystic duct was drained into the upper, the middle, and the lower third of the common hepatic duct (CHD), respectively. Lateral insertion was defined as an insertion to the right of the CHD and medial insertion to the left of the CHD. In the parallel course, the cystic duct was considered as having a joint practice with EHBD for at least 2 cm. Statistical Analysis The statistical analyses were performed with SPSS software, version 21 (Armonk, NY, IBM Corp). The descriptive statistics of the data are described as mean&,plusmn SD and frequency. The Chi square test was also applied to analyze the data. P&,lt 0.05 was considered to be statistically significant.ResultsAmong the 350 MRCP reviewed images we could distinguish the cystic duct insertion site to the EHBD in 290 cases (82%). The non-visualization of the cystic duct insertion site was mainly due to the previous history of cholecystectomy and liver transplant, ascitic fluid in the abdomen, adjacent ductal pathology, or the overlapping of structures. Patients had a mean age of 51.2&,plusmn 18.9 years. 144 (49.7%) cases were men, and 146 (50.3%) were women. Approximately, 247 cases (85.1%) showed mid-third insertion, 32 (11.1%) high insertion, and 11 (3.8%) low insertion. The cystic duct&,rsquo s classic insertion site at the middle part of EHBD from lateral was seen in 224 cases (77.2%) (figure 1,). The anatomic variations of the cystic duct are summarized in table 1,.Figure 1. Coronal maximum intensity projection (MIP) reformat illustrates normal lateral insertion of cystic duct to the lateral aspect of the extrahepatic bile duct (EHBD) (arrow)Types of CD insertionN (%)Lateral aspect of middle third of EHBD224 (77.24%)Anterior spiral medial8 (2.76%)Posterior spiral medial14 (4.83%)Low insertion6 (2.07%)Parallel course3 (1.03%)Spiral medial low2 (0.69%)High to proximal EHBD27 (9.31%)High to RHD5 (1.72%)Short CD1 (0.35%)Total290 (100%)EHBD, Extrahepatic bile duct RHD, Right hepatic duct |
| نویسندگان مقاله |
Alireza Taghavi |
Gastroenterohepatology Research Center (GRC), Department of Gastroenterology and Hepatology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Masoud Azizi |
Gastroenterohepatology Research Center (GRC), Department of Gastroenterology and Hepatology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Alireza Rasekhi |
Medical Imaging Research Center (MIRC), Department of Radiology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Zeinab Gholami |
Medical Imaging Research Center (MIRC), Department of Radiology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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