Long-term follow-up of neoplastic pancreatic cysts without high-risk stigmata: how often do we change treatment strategy because of malignant transformation?

Abdominal ultrasound in the characterization of branch-duct intraductal papillary mucinous neoplasms: A new tool for surveillance of low-risk patients?

BACKGROUND

Magnetic resonance imaging (MRI) is regarded as gold-standard for intraductal papillary mucinous neoplasms (IPMNs) follow-up. Given the low risk of transformation and the increasing population under surveillance, there is growing interest in identifying optimal follow-up strategies.

AIM

To evaluate reliability of abdominal ultrasound (US) for characterization of low-risk IPMN, compared to MRI.

METHODS

Prospective monocentric study among 79 consecutive patients with a suspected BD-IPMN on US. Each patient underwent confirmatory MRI. We evaluated Cohen's kappa statistic and concordance rate (CR) between MRI and US.

RESULTS

Of 79 suspected IPMNs on US, MRI confirmed 71 BD-IPMNs. There was high agreement for cyst location and number (CR and kappa of 77.5 % and 81.7 % and 0.66±0.08 and 0.62±0.11 respectively). We found high agreement for cyst size (CR=96.5 %, kappa=0.93±0.05) and main pancreatic duct (MPD) dilatation (CR=100 %, kappa=1). There was a good agreement for thickened septa (CR=80.3 %, kappa=0.38±0.12). US seems inferior to MRI for the identification of mural nodules < 5 mm (CR=97.2 %, kappa=0).

CONCLUSIONS

In a cohort of low-risk BD-IPMN, US presented high agreement rate with MRI regarding location, number, and size. There was a good agreement for MPD dilatation and thickened septa, while US underperform for detection of mural nodules < 5 mm.

Pancreatic cyst characterization: maximum axial diameter does not measure up

BACKGROUND

Unidimensional size is commonly used to risk stratify pancreatic cysts (PCs) despite inconsistent performance. The current study aimed to determine if unidimensional size, demonstrated by maximum axial diameter (MAD), is an appropriate surrogate measurement for volume and surface area.

METHODS

Patients with cross-sectional imaging of PCs from 2012 to 2013 were identified. Cyst MAD, volume, and surface area were measured using quantitative imaging software. Non-pseudocystic PCs >1 cm were selected for inclusion to assess MAD correlation with volume and surface area. Cysts imaged twice >1 year apart were selected to evaluate volumetric growth rate.

RESULTS

In total, 195 cysts were included. Overall, MAD was strongly correlated with volume (r = 0.83) and surface area (r = 0.93). However, cysts 1-2 cm and 2-3 cm were weakly correlated with volume and surface area: r = 0.78, 0.57 and 0.82, 0.61, respectively. Cyst volumes and surface areas varied widely within unidimensional size groups with 51% and 40% of volumes and surface areas overlapping unidimensional size groups, respectively. Estimated changes in volume poorly predicted measured changes in volume with 42% of cysts having >100% absolute percent difference.

CONCLUSIONS

Pancreatic cyst volume and surface area may be useful adjunct measurements to risk stratify patients and surveil cyst changes and deserves further study.

Role of abdominal ultrasound for the surveillance follow-up of pancreatic cystic neoplasms: a cost-effective safe alternative to the routine use of magnetic resonance imaging

BACKGROUND

Patients with pancreatic cystic neoplasms (PCN), without surgical indication at the time of diagnosis according to current guidelines, require lifetime image-based surveillance follow-up. In these patients, the current European evidenced-based guidelines advise magnetic resonance imaging (MRI) scanning every 6 mo in the first year, then annually for the next five years, without reference to any role for trans-abdominal ultrasound (US). In this study, we report on our clinical experience of a follow-up strategy of image-based surveillance with US, and restricted use of MRI every two years and for urgent evaluation whenever suspicious changes are detected by US.

AIM

To report the results and cost-efficacy of a US-based surveillance follow-up for known PCNs, with restricted use of MRI.

METHODS

We retrospectively evaluated the records of all the patients treated in our institution with non-surgical PCN who received follow-up abdominal US and restricted MRI from the time of diagnosis, between January 2012 and January 2017. After US diagnosis and MRI confirmation, all patients underwent US surveillance every 6 mo for the first year, and then annually. A MRI scan was routinely performed every 2 years, or at any stage for all suspicious US findings. In this communication, we reported the clinical results of this alternative follow-up, and the results of a comparative cost-analysis between our surveillance protocol (abdominal US and restricted MRI) and the same patient cohort that has been followed-up in strict accordance with the European guidelines recommended for an exclusive MRI-based surveillance protocol.

RESULTS

In the 5-year period, 200 patients entered the prescribed US-restricted MRI surveillance follow-up. Mean follow-up period was 25.1 ± 18.2 mo. Surgery was required in two patients (1%) because of the appearance of suspicious features at imaging (with complete concordance between the US scan and the on-demand MRI). During the follow-up, US revealed changes in PCN appearance in 28 patients (14%). These comprised main pancreatic duct dilatation (n = 1), increased size of the main cyst (n = 14) and increased number of PNC (n = 13). In all of these patients, MRI confirmed US findings, without adding more information. The bi-annual MRI identified evolution of the lesions not identified by US in only 11 patients with intraductal papillary mucinous neoplasms (5.5%), largely consisting of an increased number of very small PCN (P = 0.14). The overall mean cost of surveillance, based on a theoretical use of the European evidenced-based exclusive MRI surveillance in the same group of patients, would have been 1158.9 ± 798.6 € per patient, in contrast with a significantly lower cost of 366.4 ± 348.7 € (P < 0.0001) incurred by the US-restricted MRI surveillance used at our institution.

CONCLUSION

In patients with non-surgical PCN at the time of diagnosis, US surveillance could be a safe complementary approach to MRI, delaying and reducing the numbers of second level examinations and therefore reducing the costs.

Endoscopic ultrasound-through-the-needle biopsy in pancreatic cystic lesions: A multicenter study

BACKGROUND AND AIM

Tissue acquisition in pancreatic cystic lesions (PCL) is the ideal method for diagnosis and risk stratification for malignancy of these lesions. Direct sampling from the walls of PCL with different devices has shown better results than cytology from cystic fluid. We carried out a retrospective, multicenter study to evaluate the feasibility, safety, and diagnostic yield of a micro-forceps, specifically designed to be used through a 19-gauge needle after endoscopic ultrasonography (EUS)-guided puncture of PCL.

METHODS

We retrospectively collected data from patients who underwent EUS-through-the-needle biopsy (EUS-TTNB) in PCL at six referral centers.

RESULTS

The sampling procedure was carried out in 56 patients (mean age 57.5 ± 13.1 years, M:F 17:39), and was technically successful in all of them (100%; 95% confidence interval [CI], 94-100%). Adverse events occurred in 9/56 (16.1%; 95% CI, 8-28%) patients, with self-limited intracystic hemorrhage the most common (7/56, 12.5%; 95% CI, 5-24%). All adverse events were mild, and resolved without any specific intervention. Specimens were considered adequate for histological diagnosis in 47/56 (83.9%; 95% CI, 72-92%). In two of these patients, despite the histological adequacy, a diagnosis could not be reached. In two other cases, a specimen sufficient for a cytological diagnosis was obtained. Overall diagnostic yield by combining cytological and histological samples was 47/56 (83.9%; 95% CI, 72-92%).

CONCLUSION

EUS-TTNB with micro-forceps in PCL is feasible, safe, and has a high diagnostic yield. Future prospective studies are needed to better assess the clinical impact of EUS-TTNB on the management of PCL.

Clinical outcomes of endoscopic ultrasound-guided ethanol ablation for pancreatic cystic lesions compared with the natural course: a propensity score matching analysis

BACKGROUND

Endoscopic ultrasound-guided ethanol ablation (EUS-EA) is a recently introduced treatment for pancreatic cystic lesions (PCLs). However, clinical benefits such as survival gain and maintenance of quality of life (QOL) have not been fully established. The aim of this study was to evaluate the clinical benefits of EUS-EA compared with the natural course (NC) of PCLs.

METHODS

This retrospective comparative study of patients with PCLs investigated an EUS-EA group (n = 118) and an NC group (n = 428). Propensity score matching (PSM) analysis was applied to minimize the effects of selection bias. The overall survival as the primary outcome and the surgical resection rate and complete remission (CR) rate as the secondary outcomes were evaluated.

RESULTS

Between 84 matched pairs of both groups, there were no significant differences in the baseline clinical characteristics and the mean follow-up duration (78.88 ± 38.86, 75.90 ± 57.46 months, p = 0.694). Overall survival did not differ significantly (194.12 ± 5.60, 247.54 ± 12.70 months, p = 0.235). The surgical resection rate (4.8% versus 26.2%, p < 0.001) was significantly lower in the EUS-EA group. CR was observed only in the EUS-EA group and the CR rate was 32.1%.

CONCLUSIONS

EUS-EA for PCLs with low risk of malignancy might not be able to obtain a survival benefit, but showed maintenance of QOL by avoidance of unnecessary surgery, and a certain level of CR when compared to the NC. EUS-EA could be considered a useful treatment option for these, but careful application is needed because of the limited effects in some types of PCLs.