Introduction

Santorinicele and wirsungocele are rare anomalies characterized by the cystic dilatation of the terminal portion of the dorsal (santorini) or ventral (wirsung) pancreatic duct. Pancreas divisum (PD) is the lack of fusion between the dorsal and ventral pancreatic anlagen. Previous studies explored the association between pancreatitis and santorinicele/PD; however, the conclusions were contradictory. Also, a systematic evaluation on wirsungocele was lacking (1-3).The purpose of this study was to investigate the potential associating association among pancreatitis, pancreas divisum (PD), and santorinicele or wirsungocele (two types of pancreatic ductal variations) based on three-dimensional magnetic resonance cholangiopancreatography (3D-MRCP).

Materials and Methods

This retrospective study was approved by the local ethics review and comprised 75 participants according to the flow chart. The magnetic resonance imaging examinations were performed on either 1.5T (Signa, General Electric, Japan) or 3.0T (Ingenia, Philips Healthcare, Best, Netherlands) unit. The MR protocols included three-dimensional magnetic resonance cholangiopancreatography (3D-MRCP). For the 1.5T scanner, the 3D-MRCP sequencing was performed with T2-weighted fast recovery fast spin-echo under breath-triggering conditions. For the 3T scanner, the 3D-MRCP sequencing was performed with T2-weighted turbo spin-echo sequences after breath holding. All images were obtained in oblique coronal planes, and maximum intensity projection (MIP) image was reconstructed. All participants were divided into two groups: (1) santorinicele (n = 57); and (2) wirsungocele (n = 18). The 3D-MRCP sequence was acquired. Images were evaluated for the presence of santorinicele, wirsungocele, and PD. The states of pancreatitis were assessed according to the clinical and imaging instructors (4,5). The diagnostic sensitivity of MRCP was calculated. ERCP/EUS served as the reference standard. The chi-square and correlation tests were used to evaluate two groups with PD and pancreatitis. Subsets (a: patients with santorinicele developed pancreatitis; b: patients with santorinicele and PD did not develop pancreatitis; c: patients with santorinicele and PD developed pancreatitis) within the santorinicele group were assessed using the least significant difference (LSD) t test. An estimate of the relative risk of acquiring pancreatitis was calculated.

Results

A total of 57 patients were included in the santorinicele group (14 men, 43 women; age range, 11–82 years; average age, 53.96 years), and 18 patients were included in the wirsungocele group (5 men, 13 women; age range, 23–78 years; average age, 56.39 years). As shown in Table1, the sensitivity of MRCP combined with MIP in detecting santorinicele and wirsungocele showed no difference (70.2% and 77.8%). PD is more common in patients with santorinicele than in those with wirsungocele（78.9% and 11.1%, P < 0.05, r = 0.599）. Pancreatitis accounted for 59.6% in the santorinicele group, which was higher than that in the wirsungocele group (59.6% and 11.1%, P < 0.05, r = 0.416), and for those with santorinicele, the relative risk of pancreatitis was 5.368 (95%CI: 1.428–20.176). Patients with santorinicele tended to be younger than patients with santorinicele and PD after developing pancreatitis.

Discussion

Previous studies acknowledged the value of MRCP in depicting ductal systems (6). In this study, MRCP showed relatively good sensitivity, but was still inferior to ERCP. The accuracy of MRCP has improved a lot with increasingly advanced techniques. Thus, it was assumed that MRCP could be comparable with continuous technique advancement. Many patients with pancreatitis were found to be santorinicele and PD variants, and still a part of them only had santorinicele. The result of this study supported previous findings that santorinicele and PD both had a high correlation with pancreatitis. Besides, this study demonstrated that compared with PD, santorinicele was more likely to induce pancreatitis in the early stage. Unlike santorinicele, wirsungocele might not cause pancreatitis directly but might leave people in a susceptible state.

Conclusions

MRCP displayed potential in diagnosing subtle duct-related abnormalities. Patients with santorinicele had higher risks of developing pancreatitis than those with wirsungocele. In addition, santorinicele itself was associated more closely with pancreatitis than with PD. Clinically, when patients have recurrent idiopathic pancreatitis, it is of great importance to check for santorinicele as a potential cause.

Acknowledgements

No acknowledgement found.

References

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