En Bloc Celiac Axis Resection for Pancreatic Cancer: Classification of Anatomical Variants Based on Tumor Extent

Abstract

En bloc celiac axis resection (CAR) for pancreatic cancer is considered increasingly after modern neoadjuvant chemotherapy (NAC). Appleby and distal pancreatectomy with CAR are anatomically inaccurate terms, as tumors can extend beyond celiac axis proper, requiring concurrent resection of the proper hepatic artery and/or superior mesenteric artery. A 3-level classification for CAR (class 1, 2, or 3) was developed after retrospective review of an arterial resection database describing anatomical variants that dictate pancreatectomy-type, formal arterial revascularization, and gastric preservation. Perioperative and oncologic outcomes were assessed. Of 90 CARs for pancreatic cancer, 89% patients received NAC, 35% requiring chemotherapeutic switch. There were 41 class 1, 33 class 2, and 16 class 3 CARs, with arterial and venous revascularization performed 62% and 66%, respectively. Ninety-day mortality decreased to 4% in the last 50 cases (p= 0.035); major morbidity was unchanged (55%). Any hepatic or gastric ischemia occurred in 20% and 10% patients, respectively, and arterial revascularization was protective. R0 resection rate (88%) was associated with chemoradiation (p= 0.004). Median overall survival was 36.2 months, superior with NAC (8.0 vs. 43.5 months). Predictors of survival after NAC included chemotherapy duration, carbohydrate antigen 19-9 response, pathologic response, and lymph node status. Major pathologic response (p= 0.036) and extended duration NAC (p= 0.007) were independent predictors on multivariate analysis. Current terminology for CAR inadequately describes all operative variants. Our classification, based on the largest single-center series, allows complex operative planning and standardized reporting across institutions. Extent of arterial involvement determines pancreatectomy type, need for arterial revascularization, and likelihood of gastric preservation. Operative mortality has improved, morbidity remains significant, and survival favorable after extended NAC with associated pathologic responses; given these factors, CAR should only be considered in fit patients with objective NAC responses at specialized centers.