Prediction of Pancreatogenic Diabetes After Partial Resection of the Pancreas

Research Protocol:

At the first preoperative examination in the Abdominal Surgery Outpatient Clinic of the University Medical Centre Ljubljana, inclusion and exclusion criteria for the study will be considered and the suitable patients will recieve oral and written explanation about the purpuse, course and nature of the study (day 0). After obtaining written consent from patients, the investigators will collect demographic data (gender, age), data from each participant's medical records (associated diseases, list of regular therapies, etc.) and clinical data on the underlying pancreatic disease (including abdominal CT findings). The anthropometric measurements (body weight and hight), vital sign measurements (blood pressure, pulse) and laboratory markers, that are routinely analyzed before the PRP, will be determined. Additionally, HbA1c, serum fasting insulin and C-peptide will be measured and an oral glucose tolerance test (OGTT) administered,according to a standardized procedure with a standard fasting period. The degree of insulin resistance (HOMA-IR and CGR) will be assessed. Blood analyses will be conducted at the Laboratory of the Clinical Institute of Clinical Chemistry and Biochemistry and the Clinic of Nuclear Medicine of the University Medical Centre Ljubljana.

According to clinical indications, the participants will then be called for the PRP (e.g., distal pancreatectomy, pancreatoduodenectomy, or other form of partial resection), which will be carried out at the Clinical Department of Abdominal Surgery at the University Medical Center in Ljubljana. The pathological examination of the removed part of the pancreas will be undertaken as part of the routine postoperative analysis at the Institute of Pathology, Faculty of Medicine, University of Ljubljana. In the removed pancreatic tissue the proportion of β cells, fat, and fibrous tissue will be assessed during patohistological analysis.

Three months after PRP, which coincides with the regular postoperative check-up with the abdominal surgeon, there will be a follow-up examination in Abdominal Surgery Outpatient Clinic of the University Medical Centre Ljubljana. The same data will be collected as before PRP and HOMA-IR and CGR recalculated. Likewise, patients will undergo a follow-up abdominal CT as part of routine clinical practice, where using a computer program, the volume of tissue removed, as well as the fat and fibrous tissue will be compared to the examination before the PRP. This time point after the PRP was chosen as clinically feasible and methodologically suitable for assessing early postoperative endocrine dysfunction of the pancreas, as it allows monitoring of metabolic changes after resection with minimal additional burden on the patients. The three-month follow-up also reduces the impact of long-term confounding factors, such as the progression of malignant disease, cachexia, prolonged systemic oncological treatment, and loss of patients from follow-up. When interpreting the results, the investigators will nevertheless take into account postoperative complications, the introduction of chemotherapy, the use of glucocorticoids, nutritional status, and other factors that can affect glucose metabolism.

All the obtained data will be statistically analyzed, and a statistical predictive model for the occurrence of pancreatogenic diabetes after partial pancreatic resection will be constructed.To reduce the possibility of variability between different observers, histopathological analyses will be performed by one pathologist and CT analyses by one radiologist.