The role of non-invasive preoperative imaging techniques in predicting the risk of pancreatic fistula development in pancreaticoduodenal tumours

Abstract

Background. In pancreaticoduodenal tumours, pancreaticoduodenectomy (PDE) is a radical surgical intervention. The most important stage of the operation is the pancreaticojejunoanastomosis (PEA), the admissibility of which depends on many factors: the degree of fibrous changes in the pancreatic parenchyma, the degree of mechanical jaundice, and the operating surgeon’s technique. Identification of factors that reflect changes in the structure of the pancreatic parenchyma and its ductal system, which are important predictors in predicting the risk of developing pancreatic fistula (PF) after PDE, is of great scientific importance. Purpose. Evaluation of changes in the structure of the pancreatic parenchyma and its ductal system using non-invasive preoperative imaging methods in predicting the risk of pancreatic fistula development during pancreaticoduodenectomy. Materials and Methods. This study included 302 patients who underwent pancreaticoduodenectomy. Mechanical jaundice was detected in 246 (81.5%) patients, 56 (18.5%) patients had no jaundice, the age of patients ranged from 31 to 77 years, 178 (58.9%) were men and 124 (41.1%) were women. Ultrasound elastography and multidetector computed tomography were used for preoperative non-invasive visualisation of the degree of changes in the pancreatic parenchyma and its ductal system. The following parameters of visualisation of the pancreatic parenchyma with an assessment of the anatomical features of the isthmus and the duct of Wirsung were identified: diameter and cross-sectional area of the duct of Wirsung (at the level of the isthmus), width and thickness of the pancreas (at the level of the isthmus), cross-sectional area of the pancreatic isthmus (without the area of the duct of Wirsung), native density, and stiffness of the pancreatic parenchyma. Results and discussion. The ROC analysis of the parameters for assessing the state of the parenchyma of the pancreas and the duct of Wirsung obtained from computed tomography made it possible to determine the validity of these indicators in predicting the risk of developing PF. According to the results of the ROC analysis, the following indicators were identified as markers of moderate risk of developing PF: the diameter of the duct of Wirsung is less than 4 mm, the cross-sectional area of the duct of Wirsung is less than 0.23 cm2 , the thickness of the isthmus of the pancreas is greater than 15 mm, the width of the isthmus of the pancreas is greater than 19 mm, the cross-sectional area of the isthmus of the pancreas (without the area of the duct of Wirsung) is greater than 3 cm2 , and the native density is greater than 24 HU. To assess the high risk of developing PF, the use of ROC analysis allowed us to establish the high quality of diagnostic models for such computed tomography parameters as the diameter of the duct of Wirsung – the area under the ROC curve is 0.965, the cross-sectional area of the duct of Wirsung – AUC is 0.894, the cross-sectional area of the isthmus of the pancreas (without the area of the duct of Wirsung) – AUC is 0.873, the width of the isthmus of the pancreas – the area under the ROC curve is 0.859, the native density – AUC is 0.844. Determination of the parameter of stiffness of the pancreatic parenchyma by shear wave elastography in predicting high and moderate risk of developing PF also corresponded to the high quality of the diagnostic model. Conclusions. The use of non-invasive imaging methods allows changes in the structure of the pancreatic parenchyma, anatomical features of the pancreatic isthmus and the duct of Wirsung to be detected at the preoperative stage, the risk of developing a pancreatic fistula to be predicted and the number of complications during pancreaticoduodenectomy to be reduced.