Invasive and Non-Invasive Diagnosis of Pancreatic Fibrosis in Patients with Complicated Forms of Chronic Pancreatitis

Abstract

The purpose of the study was to identify the patterns of changes in the state of the parenchyma of the pancreas in patients with complicated forms of chronic pancreatitis with evaluation of the diagnostic effectiveness of shear wave elastometry (graphy). Materials and methods. For the period from 2006 to 2018 58 patients with complicated forms of chronic pancreatitis were examined. The average age of patients is (47.1±3.2) years old. The medical history ranged from 3 to 15 years. The basis of morphological studies were biopsies of the pancreas obtained during surgery. Ultrasound elastometry and pancreatic parenchymal elastography were performed by transcutaneous shear wave approach in Shear Wave Elastography. Software consistency was assessed by the nature of the color mapping. Results and discussion. The morphometry of the volume parts of the structural components of the pancreas showed that with the development of complicated chronic pancreatitis there is an increase in the area of fibrous tissue and a decrease in the area of acinar components. The proof of this is the strong inverse relationship between the degree of fibrosis and the volume fraction of acinar tissue (r= -0.83; р <0.05), as well as the direct relationship between the degree of fibrosis and the volume fraction of connective tissue (r=0.61; р <0.05). If at a fibrosis of the III degree acinar tissue occupied (25.39±2.01)%, connective – (64.33±3.85)%, fatty – (6.42±4.48)%, at a fibrosis of the IV degree noted the following: the proportion of acinar tissue was only (2.86±0.76)%, connective – (74.11±4.17)%, and (20.14±4.29)% was adipose tissue. Such manifestations indicated severe irreversible changes in the external secretory function of the pancreas. When assessing changes in the stiffness of the pancreatic parenchyma with the deepening of fibrosis processes and data from transcutaneous shear wave elastography, it was found that the degree of fibrosis according to morphological data correlated with the degree of fibrosis according to shear wave elastography, r = 0.71; p <0.05. The following patterns were noted. Grade II pancreatic fibrosis was characterized by intralobular fibrosis, which covered 26-50% of the gland area, which corresponded to the shear wave elastography data in green-blue color (5.98-7.05 kPa). Grade III pancreatic fibrosis corresponded to intralobular fibrosis, which covered 51-75% of the gland area in shear wave elastography in green-yellow color (7.06-9.06 kPa). Grade IV pancreatic fibrosis was characterized by intralobular fibrosis, which covered 76-100% of the gland area, which corresponded to shear wave elastography data in yellow-red color (> 9.07 kPa). Conclusion. Thus, the objectification of shear wave elastography indicators of the pancreas based on the correlation of histological evaluation and morphometric indicators of structural changes in the pathological process allows to consider transcutaneous shear wave elastography as a promising and reliable method of non-invasive diagnosis of fibrosis in chronic pancreatitis