Anatomic variations of the pancreatic duct and their relevance with the Cambridge classification system: MRCP findings of 1158 consecutive patients

Imaging the pancreas with photon-counting CT - A review of normal pancreatic anatomy

PURPOSE

Compared to conventional energy integrating detector CT, Photon-Counting CT (PCCT) has the advantage of increased spatial resolution. The pancreas is a highly complex organ anatomically. The increased spatial resolution of PCCT challenges radiologists' knowledge of pancreatic anatomy. The purpose of this review was to review detailed macroscopic and microscopic anatomy of the pancreas in the context of current and future PCCT.

METHOD

This review is based on a literature review of all parts of pancreatic anatomy and a retrospective imaging review of PCCT scans from 20 consecutively included patients without pancreatic pathology (mean age 61.8 years, 11 female), scanned in the workup of pancreatic cancer with a contrast enhanced multiphase protocol. Two radiologists assessed the visibility of the main and accessory pancreatic ducts, side ducts, ampulla, major papilla, minor papilla, pancreatic arteries and veins, regional lymph nodes, coeliac ganglia, and coeliac plexus.

RESULTS

The macroscopic anatomy of the pancreas was consistently visualized with PCCT. Visualization of detailed anatomy of the ductal system (including side ducts), papillae, arteries, vein, lymph nodes, and innervation was possible in 90% or more of patients with moderate to good interreader agreement.

CONCLUSION

PCCT scans of the pancreas visualizes previously unseen or inconsistently seen small anatomical structures consistently. Increased knowledge of pancreatic anatomy could have importance in imaging of pancreatic cancer and other pancreatic diseases.

Meandering main pancreatic duct syndrome: a single-center cohort study and aggregated review

Background

Meandering main pancreatic duct (MMPD) refers to an uncommon ductal variant of the normal smooth curvilinear course of the pancreatic duct. More specifically, MMPD is characterized by a hairpin (reverse Z-type) or loop (loop-type) turn in the pancreatic head. It has been suggested as a predisposing factor for the development of pancreatitis. Studies regarding treatment are scarce.

Methods

We conducted a narrative review of the current literature regarding MMPD. Additionally, we present a cohort of 9 symptomatic patients treated endoscopically at our tertiary center.

Results

Seven retrospective cohort studies and 4 case reports were included in our review. Only 1 study focuses on the clinical significance of MMPD and describes a positive association between MMPD and the onset of pancreatitis, especially recurrent acute pancreatitis. Only 1 case reports an endoscopic treatment. In our cohort of 9 MMPD patients, 7 did indeed present with recurrent acute pancreatitis. Endotherapy provided substantial regression of symptoms in 6 patients, all of whom had signs of ductal hypertension.

Conclusions

Our review shows the scarcity of data regarding MMPD, especially concerning treatment, in the current literature. With our cohort, we not only hope to raise awareness of this often-neglected entity of recurrent acute pancreatitis, but also support the case for endotherapy for the first time in 9 symptomatic MMPD patients, especially in the presence of ductal hypertension.

Pancreatic congenital anomalies and their features on CT and MR imaging: a pictorial review

OBJECTIVE

To review the congenital anomalies of the pancreas with their main clinical manifestations and key imaging findings on CT and MRI.

BACKGROUND AND CLINICAL SIGNIFICANCE

Anomalies of pancreatic development are frequent and generally asymptomatic, but can mimic and predispose individuals to pancreatic or peripancreatic pathologies, such as pancreatitis or malignancy. Their correct diagnosis may help avoid unnecessary further investigations and procedures, or establish adequate treatment when they manifest clinically. Differentiating pancreatic congenital anomalies from their main radiological mimics constitutes a challenge for the radiologist and requires familiarity with key imaging findings.

CONCLUSION

The imaging findings of CT and MRI are essential for the correct diagnosis of congenital pancreatic anomalies.

Ansa Pancreatica: A Rare Culprit in Recurrent Acute Pancreatitis

Ansa pancreatica is a rare anatomical variation of the pancreatic duct system, characterized by a reversed S-shaped loop that connects the main pancreatic duct to the minor papilla. Its clinical significance, particularly with recurrent acute pancreatitis, has been a subject of interest, but remains poorly understood due to the rarity of reported cases. We report the case of a 34-year-old female with a history of multiple episodes of acute pancreatitis, diagnosed with ansa pancreatica using magnetic resonance cholangiopancreatography (MRCP). The patient presented with severe epigastric pain radiating to the back, accompanied by vomiting and nausea. Laboratory findings revealed elevated serum amylase and lipase levels. MRCP imaging identified the ansa pancreatica, showing a distinct looping ductal variant terminating near the minor papilla. The patient underwent successful endoscopic treatment with significant improvement in symptoms and no recurrence of pancreatitis at follow-up. In this case, the presence of ansa pancreatica underscores the variant's potential role in predisposing individuals to recurrent episodes of acute pancreatitis. The literature review highlights the anatomical description of ansa pancreatica and its speculated pathophysiological mechanism leading to pancreatitis, primarily due to impaired pancreatic juice drainage. Despite its rarity, recognizing ansa pancreatica is crucial for the appropriate management of idiopathic recurrent pancreatitis, especially in cases where conventional causes are absent. This case report and literature review emphasize the importance of considering ansa pancreatica in the differential diagnosis of recurrent acute pancreatitis. Further research is needed to elucidate the exact mechanism by which this anatomical variant contributes to pancreatitis and to explore potential therapeutic interventions. Awareness and early detection of ansa pancreatica can lead to targeted treatments, reducing the morbidity associated with recurrent pancreatitis episodes.

Genetic Investigations in Turkish Idiopathic Pancreatitis Patients Show Unique Characteristics

BACKGROUND/AIMS

Pancreatitis is one of the leading causes of digestive system-related hospital admissions, and it has a genetic background in a considerable portion of the patients. In this study, we aimed to investigate the genetic risk factors of idiopathic pancreatitis in Turkish patients and the contribution of copy number variations to the pathogenesis.

MATERIALS AND METHODS

Idiopathic pancreatitis is defined as failure to detect risk factors despite comprehensive clinical assessments. Next-generation sequencing and multiple ligand-dependent probe amplification of PRSS1, SPINK1, CTRC, and CFTR were performed. For further genotype-phenotype correlations, patients were also questioned for the age of onset, family history, and pancreatic divisum.

RESULTS

A total of 68 idiopathic pancreatitis cases were enrolled. Variants with potential clinical significance of PRSS1 were identified in 13.4%, SPINK1 in 6.3%, CTRC in 4.7%, and CFTR in 26.5% of the patients. No copy number variants were seen in any of these genes. At least 7.4% of the participants had complex genetic etiology involving 2 genes.

CONCLUSIONS

At least 42.6% of the participants had a potential genetic risk factor. Five novel genetic variants were identified, and distinctive genetic risk factors of Turkish population were shown. The results showed that genetic etiology was frequent in pancreatitis and it was even more prominent in patients with early-onset disease. Considering that genetic risk factors may be informative for decisionmaking in the treatment options in addition to providing extensive prognostic value and familial genetic consultation; clinicians need to be more eager to offer genetic tests to pancreatitis patients.

Incidence and Clinical Implications of Anatomical Variations in the Pancreas and Its Ductal System: A Systematic Review and Meta-Analysis

OBJECTIVE

This systematic review analyzes the anatomical variants in the pancreas and its ductal system to report on their association with pancreatic pathologies.

METHODS

We conducted a search of the MEDLINE, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS databases from their inception to July 2023. The methodological quality was assessed with the Anatomical Quality Assessment (AQUA) tool. Finally, the pooled prevalence was estimated using a random effects model.

RESULTS

55 studies were found that met the eligibility criteria. The overall prevalence of pancreas divisum (PD) was 18% (95% CI = 15-21%). The prevalence of PD associated with pancreatitis was 30% (95% CI = 1-61%).

CONCLUSIONS

An anatomical variant of the pancreas such as PD may be the cause of bile duct obstruction, resulting in various clinical complications, such as pancreatitis. Hence, knowing this variant is extremely important for surgeons, especially for those who treat the gastroduodenal region.

Pancreatic ductal anatomy: more than meets the eye

PURPOSE

Anatomical variations of the pancreas are relatively frequent and often understudied. The ductal system of the pancreas has multiple variations, which are not frequently reported in the literature.

MATERIALS AND METHODS

The anatomy of the pancreas was studied through macroscopic anatomical dissection on 50 organ complexes (the pancreas, spleen, and duodenum) donated to the department of human anatomy, from patients, who died of causes not related to pancreatic diseases.

RESULTS

In type I, the main pancreatic duct (Wirsung's duct, MPD) and the accessory pancreatic duct (Santorini's duct, APD) were merged but most of the head was drained by the MPD (10% of cases). In type II, the MPD and APD were merged but most of the head was drained by the APD (4% of cases). In type III, the APD was absent and the head was drained by the MPD (14% of cases). In type IV, there was an inverted pancreas divisum where the ducts did not merge but each drained a part of the head (6% of cases). Classical pancreas divisum where the ducts did not merge but each drained a part of the head was considered as type V (4% of cases). In type VI, the MPD and APD merged and each drained a part of the head (48% of cases). In type VII, the MPD and APD merged but the upper part of the head was drained by the main pancreatic duct (4% of cases). In type VIII, the MPD and APD merged but the lower part of the head was drained by the main pancreatic duct (4% of cases). In the IX type, the MPD and APD merged but the head was drained by the branches of the MPD (6% of cases).

CONCLUSIONS

There are several drainage patterns of the pancreas. In some cases, one of the ducts provides more drainage of the gland than the other. This is clinically relevant since blockage of the main source of drainage leads to pancreatic juice stasis. It also explains cases when partial or total blockage of the duct results in the pancreatitis of an isolated zone.

Acute pancreatitis secondary to ansa pancreatica: Two new cases and review of the literature

We described two cases of acute pancreatitis secondary to ansa pancreatica. The first patient was diagnosed on MRCP and improved after standard treatment of AP. In the second case, ansa pancreatica was diagnosed on IOP. At the second episode of AP, sphincterotomy of the minor papilla was performed.

Ansa Pancreatica, an Uncommon Cause of Acute, Recurrent Pancreatitis

The pancreatic duct is vulnerable to developmental anomalies which may produce variations in its course and/or its configuration. Ansa pancreatica is the least common anatomic variant. It is characterized by the formation of an “S-shaped loop” from the main pancreatic duct to the minor papilla. Ansa pancreatica has been implicated as a cause of recurrent acute pancreatitis. We review existing literature on pancreatitis secondary to the ansa deformity and present a case of recurrent acute pancreatitis in a patient who was ultimately found to have the ansa deformity on endoscopic ultrasound.

Clinical outcome of endoscopic therapy in patients with symptomatic pancreas divisum: a Dutch cohort study

Background and study aims  Although the majority of patients with pancreas divisum (PDiv) are asymptomatic, a subgroup present with recurrent pancreatitis or pain for which endoscopic therapy may be indicated. The aim of this study was to evaluate success rates and long-term outcomes of endoscopic treatment in patients with symptomatic PDiv. Patients and methods  A multicenter, retrospective cohort study was performed. Patients with symptomatic PDiv presenting with recurrent acute pancreatitis (RAP), chronic pancreatitis (CP), or chronic abdominal pancreatic-type pain (CAP) who underwent endoscopic retrograde cholangiopancreatography (ERCP) between January 2000 and December 2019 were included. The primary outcome was clinical success, defined as either no recurrent episode of acute pancreatitis (AP) for RAP patients, no flares for CP patients, or absence of abdominal pain for patients with CAP after technically successful ERCP. Results  In 60 of 81 patients (74.1 %) a technically successful papilla minor intervention was performed. Adverse events were reported in 30 patients (37 %), with post-ERCP pancreatitis in 18 patients. The clinical success rate for patients with at least 3 months of follow-up was 42.6 %, with higher rates of success among patients presenting with RAP (44.4 %) as compared to those with CP (33.3 %) or CAP (33.3 %). Long-term sustained response was present in 40.9 % of patients with a technically successful intervention. In patients with RAP who did not completely respond to treatment, the mean number of AP episodes after treatment decreased significantly from 3.5 to 1.1 per year, and subsequently the interval between AP episodes increased from 278 to 690 days ( P  = 0.0006). A potential predictive factor of failure of clinical success after technically successful ERCP, at univariate analysis, was male sex (OR = 0.25, P  = 0.02). Conclusions  Endoscopic therapy in patients with symptomatic PDiv is moderately effective, with its highest yield in patients presenting with RAP. Future studies are needed to assess factors predictive for success of endoscopic therapy and potential risk factors for relapse after ERCP.

Ansa pancreatica: a rare cause of acute recurrent episode in chronic pancreatitis

Ansa pancreatica is a rare anatomic variation of pancreatic ducts. It is a predisposing factor of recurrent pancreatitis. In this case report, we describe a case of a 24-year-old male suffering from an ansa pancreatica with a non-patent major papilla, diagnosed on magnetic resonance cholangiopancreatography (MRCP).The ansa pancreatica was revealed by an episode of acute pancreatitis attacks in chronic pancreatitis. Endoscopic retrograde cholangiopancreatography (ERCP) confirmed important abrupt dilation in the main pancreatic duct with an ansa loop in the pancreatic duct in the head of the pancreas, and a sphincterotomy of the minor papilla was performed. The procedure was difficult and the placement of a long-term pancreatic stent during the ERCP was impossible, thus a surgical pancreatico-jejunostomy was proposed as a treatment of an ansa pancreatica with a non-patent major papilla.

Ansa pancreatica: a rare cause of acute recurrent pancreatitis

Acute pancreatitis is an inflammation of the pancreas that can be caused in rare situations by ansa pancreatica, it is a rare anatomic variation of the pancreatic ducts. It is a communication between the main pancreatic duct (Wirsung) and the accessory pancreatic duct (Santorini). We report a case of the patient, in a 44-year-old, non-alcoholic, hospitalized for acute pancreatitis stage C of Baltazar. A magnetic resonance Cholangiopancreatography (MRCP) was performed which showed a gallstone and ansa pancreatica, than an endoscopic retrograde cholangiopancreatography (ERCP) revealed an ansa pancreatica with a common bile duct clear, a sphincterotomy of the major papilla was performed. It is still not clear whether the presence of these two pathologies is a coincidence or if the ansa pancreatica is the cause of acute pancreatitis. New studies are necessary to clarify these points.

Biliary anatomy and pancreatic duct variations: A cross-sectional study

BACKGROUND/AIM

Biliary tree and pancreatic duct can appear in different variations whose proper understanding is obligatory for surgeons. Magnetic resonance cholangiopancreatography (MRCP) is considered a safe and accurate tool for evaluating biliary tree and pancreatic duct. Typical anatomy for right hepatic duct (RHD) and left hepatic duct (LHD) is reported as 57% and 63%, respectively. The most common (4-10%) pancreatic anomaly is divisum. In the present study, we evaluated and determined the prevalence of biliary tree and pancreatic duct variations among patients at a university hospital.

MATERIALS AND METHODS

The MRCP records of 370 patients from 2015 to 2017 were obtained for cross-sectional study. Images were retrospectively reviewed for variations by two independent senior radiologists. Demographic data were obtained for all the patients. Huang et al. classification was used for RHD and LHD variations. The cystic duct was reported based on its course and insertion pattern. The pancreatic duct was observed for the presence of divisum, its course, and configuration.

RESULTS

Three hundred and twenty-five patients were included in the final study. Most commonly observed variant for RHD were A1 (34.2%) and A2 (32.2%). For LHD, B1 (71.4%) was the most common variant. Cystic duct insertion was commonly seen as right lateral insertion (27.7%). Pancreatic divisum was observed in 0.6% of cases. Nationality, origin, and gender-specific variations were obtained.

CONCLUSION

Variations in biliary anatomy and pancreatic duct are very diverse and extend from the intrahepatic biliary system down to the pancreas. Performing a similar study on a larger population is mandatory to illustrate the range of variations present within the community.

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.

Pancreas divisum: a reemerging risk factor for pancreatic diseases

Pancreas divisum (PD) is the most common developmental anatomic variant of pancreatic duct. The attention towards the PD has grown significantly since there are reports that this condition may cause acute relapsing pancreatitis, chronic pancreatitis and chronic abdominal pain syndrome. Furthermore, over the years, there have been multiple reports of PD associated with different types of tumors. There is evidence that PD can be associated with pancreatic tumors (up to 12.5% of cases). The golden standard for diagnosing PD is endoscopic retrograde cholangiopancreatography, but since it is an invasive procedure magnetic resonance cholangiopancreatography with secretin is a good alternative. In case the patient is symptomatic, endoscopic or surgical treatment should be performed. This review describes the key points of the pathophysiology, diagnostic modalities, risks of pancreatitis and tumors, as well as treatment options of PD.

A pancreatic zone at higher risk of fistula after enucleation

Background

To determine predictive factors of postoperative pancreatic fistula (POPF) in patients undergoing enucleation (EN).

Methods

From 2005 to 2017, 47 patients underwent EN and had magnetic resonance imaging available for precise analysis of tumor location. Three pancreatic zones were delimited by the right side of the portal vein and the main pancreatic head duct (zone #3 comprising the lower head parenchyma and the uncinate process).

Results

The mortality and morbidity rates were 0% and 62%, respectively. POPF occurred in 23 patients (49%) and was graded as B or C (severe) in 15 patients (32%). Four patients (8.5%) developed a postoperative hemorrhage, and 5 patients (11%) needed a reintervention. In univariate and multivariate analyses, the pancreatic zone was the unique predictive factor of overall (P = .048) or severe POPF (P = .05). We did not observe any difference in postoperative courses when comparing the EN achieved in zones #1 and #2. We noted a longer operative duration (P = .016), higher overall (P = .017) and severe POPF (P = .01) rates, and longer hospital stays (P = .04) when comparing the EN achieved in zone #3 versus that in zones #1 and #2. Patients who underwent EN in zone #3 had a relative risk of developing a severe POPF of 3.22 compared with patients who underwent EN in the two other pancreatic zones.

Conclusion

Our study identifies the lower head parenchyma and the uncinate process as a high-risk zone of severe POPF after EN. Patients with planned EN in this zone could be selected and benefit from preoperative and/or intraoperative techniques to reduce the severe POPF rate.

Electronic supplementary material

The online version of this article (10.1186/s12957-018-1476-5) contains supplementary material, which is available to authorized users.

The Main Anatomical Variations of the Pancreatic Duct System: Review of the Literature and Its Importance in Surgical Practice

Anatomical variations or anomalies of the pancreatic ducts are important in the planning and performance of endoscopic retrograde cholangiopancreatography (ERCP) and surgical procedures of the pancreas. Normal pancreatic duct anatomy occurs in approximately 94.3% of cases, and multiple variations have been described for the remaining 5.7%. The purpose of this study was to review the literature on the pancreatic duct anatomy and to underline its importance in daily invasive endoscopic and surgical practice. Two main databases were searched for suitable articles published from 2000 to 2017, and results concerning more than 8,200 patients were included in the review. The most common anatomical variation was that of pancreas divisum, which appeared in approximately 4.5% of cases.