Prospective multicenter evaluation of the Moray™ micro forceps in the management of pancreatic cysts – MOBIDYC trial

Aims The risk stratification of pancreatic cysts (PC) represents a significant challenge for the gastroenterologist. New techniques, such as EUS biopsy sampling using micro forceps that pass through a needle (Moray™ Micro Forceps, EUS-TTNB) remain a topic of debate.

Methods This was a prospective, national, multicentre study that included patients with pancreatic cysts (PC) who required endoscopic ultrasound (EUS) sampling for diagnostic purposes between 2019 and 2022. The primary objective was to ascertain the histological performance of the micro forceps, specifically the ability to obtain analyzable tissue samples. Secondary objectives included technical success, diagnostic performance, and safety (NCT04200131).

Results Of the 100 consecutive patients initially included in the study, micro forceps biopsy was finally performed in 94 patients (mean age 63 years; 61.7% female). The median size of the pancreatic cyst was 33.5 mm (range 18–100 mm). A thickened wall was present in 38.3% of cases (n=36), with a solid nodule present in 14.9% (n=14) of cases. Twenty-seven patients (28.7%) exhibited main pancreatic duct dilation. The technical success rate was 100% for a mean number of biopsies of 3.94 (SD 1.13), and the histological performance was 71.3% (serous PC 25.4%, mucinous PC 14.9%, TIPMP 16.4%, NET 7, 5%, pseudocyst 5.97%, pancreatic acinar cystic transformation 5.97%, pseudopapillary and solid tumor of the pancreas 1.49%, lymphoepithelial cyst 2.99% and undetermined result 19.4%). In univariate and multivariate analysis, the proximal location of the PC (p=0.027), absence of tissue component (p=0.044) and absence of dilatation of main pancreatic duct (p=0.025) were identified as predictive factors for possible histological analysis. Twenty-three patients (24.5%) underwent surgical intervention (gold standard for histological analysis): concordance between micro forceps histology and surgical histology was 91.3%, while it was only 56.5% with the diagnosis evoked on the morphological aspect during EUS. In 22% of cases (5/23), the micro forceps biopsy resulted in a change of the presumptive diagnosis, with surgery being indicated. Two patients exhibited a discrepancy between the histology of the micro forceps and the surgical histology, resulting in the performance of excessive surgery (unilocular macrocystic serous cystadenoma). A total of fifteen complications were recorded, representing 15% of the total cases. Thirteen complications were classified as AGREE I (n=7, containing intracystic haemorrhage; n=4, causing pain; n=2, resulting in pancreatitis). One complication was classified as AGREE II (bacteremia) and one was classified as AGREE V (haemoperitoneum with fatal issue).

Conclusions EUS-TTNB enables histological analysis of PC in 71% of cases, resulting in a change in therapeutic approach in over one-half of cases. Given the associated morbidity and mortality, this technique should be employed only when other methods have been unsuccessful and in high surgical risk patient.