Pancreatoduodenectomy With Mesopancreas Dissection.A Prospective Study Comparing Artery-first Approach Versus Standard Approach

Overview

The definitions for R0 and R1 margin status after resection for pancreatic cancer are controversial.Various studies showed the rate of noncurative resections of 15- 35 % but with modified pathological examination (R1/R2) revealed the rate of R1 resection was higher ranging from 76-85 % . Verbeke CS etal. * Whether this discrepancy was caused by incomplete lymphnode dissection, perineural dissection and improper pathological examination was not yet known. * Perineural invasion was detected in 77 % of specimens of resected pancreatic cancers. So the researchers emphasized the need of new surgical classification involving mesopancreas. It can be considered as an anatomical space bounded anteriorly by the the posterior surface of the pancreatic neck, posteriorly by the pancreaticoduodenal coalescence fascia, medially by the mesenteric vessels with -nerves, lymphatics and vessels as its contents.

A Controlled clinical trial of pancreatoduodenectomy with mesopancreas dissection.A Prospective study comparing artery-first versus standard approach. * Target population: -All cases of malignant obstructive jaundice within the above criteria. * Sample size: * It will be conventional sample size of about 40 cases minimum about 20 case for each group of the both procedures * Techniques: * The procedure at Assiut university hospital consists of artery-first with l dissection at the origin of the superior mesenteric artery and the celiac trunk all along their right side of the vessels versus standard approach. * This allows a complete clearance of retro- pancreatic tissues. * -En bloc resection of the primary tumor and regional lymph nodes through complete excision of the mesopancreatic plane, utilizing the artery-first approach. * -The mesopancreatic plane consists of the pancreas head, the uncinate process of the pancreas, and the meso-pancreatoduodenum. * All the tissues that lay in this triangular space (SMA down, CT up, and SMV-PV anterior) is cleared. Then the investigators continue the dissection along the right then anterior surface of the SMV and PV until reaching the dissected posterior surface the neck of the pancreas . * Last step is the division of the neck of the pancreas. * After the specimen is removed and before it is sent to the pathology the investigators put mark on each boundary of the specimen one towards SMA, another towards PV/SMV area and the last towards the posterior surface of the mesopancreas. * This can guide the pathologist to identify the retro pancreatic margins and define whenever there is an R1 resection the exact area of invasion. Microscopic margin involvement (R1) will be defined as tumor within 1 mm of resection margin. While in standard approach at first kocharization of the duodenum ,then starting to asses the tunnel under the neck of the pancreas whether tumor infilterating PV/SMV axis and if not the investigators cut the neck of pancreas early in the procedure then continue to dissect the uncinate process and control pancreatoduodenal vessels and draining lymph nodes and LNS around portal vein and up to hepatic artery and we will add to the standard procedure the previously defined mesopancreatic triangle dissection which lies between SMA caudal, Coeliac artery cranial and PV/SMV axis anterior and the specimen will be marked and sent as previous to pathology.