The Dilemma of the Dilated Main Pancreatic Duct in the Distal Pancreatic Remnant After Proximal Pancreatectomy for IPMN

International evidence-based Kyoto guidelines for the management of intraductal papillary mucinous neoplasm of the pancreas

This study group aimed to revise the 2017 international consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, and mainly focused on five topics; the revision of high-risk stigmata (HRS) and worrisome features (WF), surveillance of non-resected IPMN, surveillance after resection of IPMN, revision of pathological aspects, and investigation of molecular markers in cyst fluid. A new development from the prior guidelines is that systematic reviews were performed for each one of these topics, and published separately to provide evidence-based recommendations. One of the highlights of these new "evidence-based guidelines" is to propose a new management algorithm, and one major revision is to include into the assessment of HRS and WF the imaging findings from endoscopic ultrasound (EUS) and the results of cytological analysis from EUS-guided fine needle aspiration technique, when this is performed. Another key element of the current guidelines is to clarify whether lifetime surveillance for small IPMNs is required, and recommends two options, "stop surveillance" or "continue surveillance for possible development of concomitant pancreatic ductal adenocarcinoma", for small unchanged BD-IPMN after 5 years surveillance. Several other points are also discussed, including identifying high-risk features for recurrence in patients who underwent resection of non-invasive IPMN with negative surgical margin, summaries of the recent observations in the pathology of IPMN. In addition, the emerging role of cyst fluid markers that can aid in distinguishing IPMN from other pancreatic cysts and identify those IPMNs that harbor high-grade dysplasia or invasive carcinoma is discussed.

Surveillance after resection of non-invasive intraductal papillary mucinous neoplasms (IPMN). A systematic review

BACKGROUND

The ideal surveillance strategy after partial pancreatectomy for non-invasive IPMN remains undefined and existing guidelines provide conflicting recommendations. The present study was developed in anticipation of the joint meeting of the International Association of Pancreatology (IAP) and the Japan Pancreas Society (JPS) held in Kyoto in July 2022.

METHODS

An international team of experts developed the four clinical questions (CQ) to operationalize issues pertaining to surveillance of patients in this context. A systematic review was designed following the PRISMA guidelines and registered in PROSPERO. The search strategy was executed in PubMed/Medline (Ovid), Embase, the Cochrane Library and Web of Science databases. Four investigators individually extracted data from the selected studies and drafted recommendations for each CQ. These were subsequently discussed and agreed upon that the IAP/JPS meeting.

RESULTS

From a total of 1098 studies identified through the initial search, 41 studies were included in the review and informed the recommendations. No studies providing level one data were identified in this systematic review, all studies included were cohort or case-control studies.

CONCLUSIONS

There is a lack of level 1 data addressing the issue of surveillance of patients following partial pancreatectomy for non-invasive IPMN. The definition of remnant pancreatic lesion in this setting is largely heterogeneous across all studies evaluated. Herein we propose an inclusive definition of remnant pancreatic lesions to guide future prospective efforts for reporting the natural history and long-term outcomes of these patients.

Should non-invasive diffuse main-duct intraductal papillary mucinous neoplasms be treated with total pancreatectomy?

BACKGROUND

Main-duct (MD) intraductal papillary mucinous neoplasm (IPMN) is associated with malignancy risk. There is a lack of consensus on treatment (partial or total pancreatectomy) when the MD is diffusely involved. We sought to characterize the pancreatic remnant fate after partial pancreatectomy for non-invasive diffuse MD-IPMN.

METHODS

Consecutive patients with partial pancreatectomy for non-invasive MD-IPMN from 2004 to 2016 were analyzed. Diffuse MD-IPMN was defined by preoperative imaging as dilation of the MD in the head of the pancreas more than 5 mm and involving the whole gland.

RESULTS

Of 127 patients with resected non-invasive MD-IPMN, 47 (37%) had diffuse MD involvement. Eleven of 47(23%) patients developed imaging evidence of progression or new cystic disease in the pancreatic remnant. Patients with diffuse MD-IPMN were older (73yrs vs 67yrs, p = 0.009), more likely to receive a pancreaticoduodenectomy (96% vs 56%, p < 0.001) and have high-grade dysplasia (51% vs 31%, p = 0.025) than those with focal MD involvement. Diffuse MD involvement was not associated with shorter PFS following partial pancreatectomy (p = 0.613).

CONCLUSION

Partial pancreatectomy is an appropriate surgical approach for diffuse MD-IPMN, and is not associated with earlier progression after surgery as compared to partial pancreatectomy for focal dilation.

The management of intraductal papillary mucinous neoplasms of the pancreas

Intraductal papillary mucinous neoplasms (IPMN) of the pancreas are one of the most common preneoplastic entities among pancreatic cystic neoplasms (PCN). Their incidence is increasing due to an extensive use of cross-sectional imaging, but management still remains controversial. Among IPMNs, the main duct (MD-IPMN) and mixed (MT-IPMN) types harbor a high risk of malignant degeneration requiring resection in most of cases. The branch duct type (BD-IPMN), on the other side, can be safely surveilled as surgical resection is limited to selected cases deemed at high risk of malignant progression according to specific clinical and radiological features. An accurate diagnosis and a correct assessment of malignant potential are often hard to achieve, and clinical management still relies on the experience of the gastroenterologist/surgeon that is called to choose between a major pancreatic resection burdened by high morbidity and mortality rates and a life-long surveillance. The purpose of this report is to summarize the available evidence supporting the current practice for the management of IPMN and to offer a useful practical guide from first observation to postoperative follow-up.