416 A Single-Centre Evaluation of Pre-Operative and Post-Operative Staging Concordance in Patients Undergoing Combined Pancreatic and Vascular Resection for Borderline Resectable Pancreatic Adenocarcinoma

Abstract Introduction Borderline-resectable pancreas cancer(BRPC) is defined by extent of peri-pancreatic vascular involvement. BRPC patients have been demonstrated to have improved survival outcomes when treated with neo-adjuvant systemic chemotherapy(NAC). Pre-operative anatomical interpretation to define those likely to benefit from NAC is a crucial step in ensuring patients undergo optimal treatments. Method A prospectively maintained surgical database was reviewed between 1/1/2020 and 31/12/2023. Patients with incomplete data were excluded. We reviewed pre-operative radiological(CT) and endoscopic ultrasound(EUS) reports to compare with intra-operative findings and post-operative histology. Results 19 patients underwent combined Whipple/Total Pancreatectomy and vascular(SMV/PV) resection: 8 underwent NAC, 1 was deemed physiologically inappropriate for NAC and 10 were intra-operatively diagnosed with vascular involvement. Of 8 patients undergoing NAC, pre-operative radiology described vessel abutment/contact in 100% and deformity in 63%; whereas, EUS identified vessel involvement in 63%. Histological vein involvement was confirmed in 7/8. The patient deemed physiologically inappropriate for NAC was reported as having vessel contact at CT and contour deformity on EUS; however, post-operative histology reported no venous involvement. All 10 operatively diagnosed patients were assessed as having no vessel involvement at pre-operative radiology/EUS; histology confirmed venous involvement in only 1. Conclusions Pre-operative anatomical interpretation and staging of BRPC remains crucial but challenging. In this subset of patients undergoing combined pancreatic/vascular resection, the optimum sensitivity/specificity was defined by pre-operative radiological assessment. Intra-operative diagnoses of vessel involvement were more likely due to inflammation/desmoplastic change. A multi-modal approach may improve accuracy of pre-operative assessment of vascular involvement.