Radio-anatomic study of the pancreatic duct by MR cholangiopancreatography

Exploring the variations of the pancreatic ductal system: a systematic review and meta-analysis of observational studies

The exocrine part of the pancreas has a duct system called the pancreatic ductal system (PDS). Its mechanism of development is complex, and any reorganization during early embryogenesis can give rise to anatomical variants. The aim of this study is to collect, classify, and analyze published evidence on the importance of anatomical variants of the PDS, addressing gaps in our understanding of such variations. The MEDLINE, Web of Science, Embase, and Google Scholar databases were searched to identify publications relevant to this review. R studio with meta-package was used for data extraction, risk of bias estimation, and statistical analysis. A total of 64 studies out of 1,778 proved suitable for this review and metanalysis. The meta-analysis computed the prevalence of normal variants of the PDS (92% of 10,514 subjects). Type 3 variants and "descending" subtypes of the main pancreatic duct (MPD) predominated in the pooled samples. The mean lengths of the MPD and accessory pancreatic duct (APD) were 16.53 cm and 3.36 cm, respectively. The mean diameters of the MPD at the head and the APD were 3.43 mm and 1.69 mm, respectively. The APD was present in only 41% of samples, and the long type predominated. The pancreatic ductal anatomy is highly variable, and the incorrect identification of variants may be challenging for surgeons during ductal anastomosis with gut, failure to which may often cause ductal obstruction or pseudocysts formation.

Clinical importance of main pancreatic duct variants and possible correlation with pancreatic diseases

Background: Except for pancreas divisum (PD), the prevalence of anatomic variants of the main pancreatic duct (MPD) seems to be insufficiently investigated. To date, their role in the occurrence of pancreatic exocrine insufficiency (PEI) and morphological changes suggestive of chronic pancreatitis (CP) has remained unclear.Methods: A systematic review was performed, searching MEDLINE and Web of Science, limited to articles published between 1960 and 1 June 2019.Results: Our review included a total number of 3234 subjects. The most common variant of MPD was type 3, followed by type 1, indicating MPD drainage pattern into major papilla (MP) as the most frequent. A sub-variant of type 3, known as 'reverse pancreas divisum' had a prevalence of 2.2%. Type 4 variant- PD, was found in 6.4% of all cases. The most common sub-variant of PD was complete PD, followed by incomplete PD and variant with MPD as only pancreatic duct. Type 5 variant (including ansa pancreatica) was present in 2.9% of subjects. Apart from one study with a significantly higher frequency of morphological changes suggestive of CP in patients with ansa pancreatica, the studies stated no significant association between pancreatic disease and MPD variants. Furthermore, only one study examined the influence of MPD variants on exocrine pancreatic function. Although equivocal, this association is most likely found to be insignificant.Conclusion: To elucidate linkage between MPD variants and the occurrence of chronic pancreatitis and impairment of pancreatic exocrine function, further clinical investigations are warranted.

Imaging of the pancreatic duct by linear endoscopic ultrasound

The current gold standard investigation for anatomic exploration of the pancreatic duct (PD) is endoscopic retrograde cholangiopancreatography. Magnetic resonance cholangiopancreatography is a noninvasive method for exploration of the PD. A comprehensive evaluation of the course of PD and its branches has not been described by endoscopic ultrasound (EUS). In this article, we describe the techniques of imaging of PD using linear EUS.

Pancreatic duct patterns in acute pancreatitis: a MRI study

OBJECTIVES

To study the MRI findings of the pancreatic duct in patients with acute pancreatitis.

MATERIALS AND METHODS

A total of 239 patients with acute pancreatitis and 125 controls were analyzed in this study. The severity of acute pancreatitis was graded using the MR severity index (MRSI) and the Acute Physiology And Chronic Healthy Evaluation II(APACHE II) scoring systems. The number of main pancreatic duct (MPD) segments visualized, and both MPD diameter and pancreatic duct disruption were noted and compared with the severity of acute pancreatitis.

RESULTS

The frequency of MPD segment visualization in the control group was higher than that in the acute pancreatitis group (p<0.05). The number of MPD segments visualized was negatively correlated with the MRSI score (p<0.05) and the APACHE II score (p<0.05). There was no difference in the MPD diameter between the acute pancreatitis and control groups or among the patients with different severities of acute pancreatitis (p>0.05). The prevalence of pancreatic duct disruption was 7.9% in the acute pancreatitis group. The prevalences of pancreatic duct disruption were 4.8% and 15.3% in the mild and severe acute pancreatitis groups based on the APACHE II score, respectively, and were 0%, 5.7% and 43.5% in the mild, moderate and severe acute pancreatitis groups according the MRSI score, respectively. The prevalence of pancreatic duct disruption was correlated with the severity of acute pancreatitis based on the APACHE II score (p<0.05) and MRSI score (p<0.05).

CONCLUSION

The pancreatic duct in acute pancreatitis patients was of normal diameter. The number of MPD segments visualized and visible pancreatic duct disruption on MRI may be supplementary indicators for determining the severity of acute pancreatitis.

Pancreatic duct diversity

OBJECTIVES

The formation of the pancreatic duct system is the result of the fusion of 2 embryonic buds, the ventral and dorsal primordia. Frequently, this fusion process is localized in the pancreatic head; variations, however, may account for the structural diversity of the duct system. Pancreatic duct anomalies and diversity of body and tail are thought to be casuistic.

METHODS

Ninety-nine consecutive adult autopsies with reference to macroscopic anomalies in the distal part of the gland were evaluated. Pancreatograms were performed after large duodenal papilla cannulation. Ducts parallel to gland axis with a diameter of at least one third of the main pancreatic duct at the junction point and aberrant duct with different shapes and/or abnormal third-degree ductuli architecture were noted.

RESULTS

Our study revealed a 9.9% frequency of main pancreatic duct diversity in the pancreatic corpus and tail. Eleven atypical ducts were visible, 9 cranially and 2 caudally from the main pancreatic duct.

CONCLUSIONS

The pancreatic duct system in the body and the tail presents abnormal configuration not described in the past.

Assessment of the main pancreatic duct using computed tomography with multiplanar reconstructions

The aim of this study was to assess the morphology of the main pancreatic duct (MPD) using multiplanar reconstructions and to compare this with the morphology of the MPD of anatomic subjects.

MATERIALS AND METHODS

The morphology of the MPD was studied by means of multiplanar reconstructions obtained on the one hand from thin tomodensitometric slices and on the other hand from the dissection of anatomic subjects. This study involved 15 subjects in each group.

RESULTS

Full multiplanar reconstruction was obtained in 13 cases. In 2 cases, the isthmus did not appear in the reconstructions. The morphology of the MPD was similar in both groups. The length of the MPD was identical at the head and isthmus of the pancreas in both groups but was greater in the dissection group than in the reconstruction group in the body and tail areas of the pancreas. The diameter of the MPD was greater at the head of the pancreas in the dissection group and was identical in both groups for the other segments of the MPD.

CONCLUSIONS

Multiplanar tomodensitometric reconstruction of the main pancreatic duct is feasible. This new technique, currently under evaluation, could allow the study of canalar pathologies of the pancreas through tomodensitometry.

Aspects du pancréas normal. Variantes et malformations

Major advances have occurred with regards to imaging of the pancreas. In spite of harmonic imaging, US remains limited. Multi-detector CT allows excellent evaluation of the pancreatic parenchyma with multiplanar ductal and vascular reformations. MRI provides excellent evaluation of the pancreatic parenchyma using fat suppressed T1W images and excellent evaluation of the biliary tract and pancreatic duct using T2W images. Senile pancreas is characterized by atrophy and ductal dilatation, sometimes microcystic. Fatty infiltration of the pancreas could be focal or diffuse. Pancreas divisum is characterized by the absence of fusion of the pancreatic ducts with several anatomic variants. Annular pancreas results from malrotation of the pancreatic buds. MRI is the best technique to diagnose these malformations.