Chronic Asymptomatic Pancreatic Hyperenzymemia (CAPH): Meta-analysis of pancreatic findings at second-level imaging

Background/objectives: Data estimating the prevalence of significant findings during the investigation of patients with Chronic Asymptomatic Pancreatic Hyperenzymemia (CAPH) are scanty and heterogeneous, and the diagnostic approach is therefore uncertain. The aim of this study was to meta-analyze pancreatic abnormalities detected at second-level imaging in patients with CAPH.

Methods: Pubmed database was searched until September 2018 for articles evaluating CAPH patients through MRI-Cholangio-Pancreatography with/without secretin (MRCP or s-MRCP) or Endoscopic Ultrasound (EUS). The methodology was developed from PRISMA checklist. Pooled prevalences of pancreatic findings were calculated, with subgroup analyses according to imaging modality. Quality of the studies, publication bias and heterogeneity were analyzed.

Results: In 8 articles describing 521 patients with CAPH, pooled prevalence of normal imaging was 56.6% [95%CI (CI) 41.9-70.2; I² = 88.6%). Prevalences of neoplasia, chronic pancreatitis, pancreatic cysts and benign abnormalities were 2.2% [CI1.2-4.1; I² = 0%], 16.2% [CI10.2-24.8; I² = 71.5%], 12.8% [CI8.2-19.3; I² = 64.7%] and 17.2% [CI11.9-24.2; I² = 71.5%] respectively. In sub-analyses, EUS and s-CPRM were less frequently normal and diagnosed more "early" chronic pancreatitis, while neoplastic lesions were still rare.

Conclusions: In CAPH patients, second-level pancreatic imaging is normal in 56% of the cases, neoplastic lesions are rare and the rate of pancreatic cysts is similar to that seen as incidental findings. More than one third of patients are diagnosed with abnormalities whose prognostic significance is uncertain. Despite the superior sensitivity of EUS or s-CPRM, the less costly/invasive and more available contrast-enhanced MRCP does not seem to miss relevant findings in this setting.