Department of Surgery, National Taiwan University Hospital Pancreaticoduodenectomy with or without systematic Mesopancreas Dissection: Comparison of Morbidity, Mortality and Short-term Outcome 胰十二指腸切除合併系統化胰內緣軟組織廓清：手術併發症、死亡率及短期預後比較 吳健暉、郭庭均、吳經閔、楊卿堯、田郁文 台灣大學附設醫院一般外科 Chien-Hui Wu, M.D., Ting-Chun Kuo, M.D., Jin-Ming Wu, M.D., Ph.D., Ching-Yao Yang, M.D., Ph.D., Yu-Wen Tien, M.D., Ph.D Department of Surgery, National Taiwan University Hospital

Concept of mesopancreas dissection First pancreaticoduodenectomy (Whipple,Ann Surg 1935) Regional pancreatectomy in 1970s failed to improve outcomes (Yeo, Ann Surg 2002)(Nguyen, J Gastrointest Surg 2003)(Pedrazzoli, Ann Surg 1998) Resection margin(R0/R1) impacts long-term survival ISGPS (Surgery 2014) : extensive lymphadenectomy including 16 para-aortic area and complete lymphadenectomy around the superior mesenteric artery (SMA) are not routinely recommended The goal of mesopancreatic resection (area around the SMA) is for the margin (R-factor) rather than to stage or control the nodal spread (N-factor) (Peparini, 2015 and 2016) Neoadjuvant treatment era in the future

Mesopancreas is primary site of R1 resection Prospectively tested , 100 pancreatic head specimens 35 were excluded owing to the pathohistological diagnosis 32 cancer resections were classified R0 (49.2%) 33 cancer resections were classified R1 (50.8%) Mesopancreas was infiltrated in 22 of the 33 R1 resection specimens (66.6%) Gaedcke, Langenbecks Arch Surg, 2010

What is mesopancreas Gockel,2007 WORLD J SURG ONCOL Perineural lymphatic layer located dorsal to the pancreas, extending from the posterior surface of the pancreatic head to behind the mesenteric vessels (SMV and SMA) Gaedcke,2010 Langenbecks Arch Surg Peripancreatic fatty tissue posterior to the pancreatic head and lateral to the SMA Adham,2012 Eur J Surg Oncol Triangle with : posterior surface of the SMV and portal vein; anterior surface of the aorta between the celiac trunk and the origin of the SMA; lateral boundaries limited by the right semicircumferences of the celiac trunk and SMA plexus Kawabata,2012 Cluster of soft connective tissues along the IPDA and the first jejunal artery (FJA) including circumferential tissue of SMA

Systematic mesopancreas dissection plPh-I and plPh-II: first and second nerve plexuses of the pancreas head pl-SMA: nerve plexus around the SMA IPDA: inferior pancreatoduodenal arteries JA: jejunal arteries JV: jejunal veins HGCT: Henle's gastrocolic trunk (Inoue, Ann Surg 2015)

Systematic mesopancreas dissection (Inoue, Ann Surg 2015)

Systematic mesopancreas dissection Level 1 dissection-Simple mesopancreas division without LN dissection preserving pl-SMA, JAs, and JVs no dissection on the left side of SMA mesojejunum can be preserved (Inoue, Ann Surg 2015)

Systematic mesopancreas dissection Level 2 dissection - En bloc LNs dissection in the mesopancreas by the central vessel ligation technique central vessel ligation, IPDA is ligated at its root (common trunk with JA) resection of the corresponding LNs and mesojejunum (Inoue, Ann Surg 2015)

Systematic mesopancreas dissection Level 3 dissection - En bloc mesopancreas resection with right hemicircumferential pl-SMA dissection encompassing the right hemicircle of the pl-SMA (11 to 5 o’clock, peeling off the pl-SMA like a plate) dissection along the SMA, the corresponding mesojejunum is also resected (Inoue, Ann Surg 2015)

Mesopancreas dissection experience in NTUH

Level 1 mesopancreas dissection in NTUH

Level 1 mesopancreas dissection in NTUH

Level 2 mesopancreas dissection in NTUH

Level 2 mesopancreas dissection in NTUH

Level 2 mesopancreas dissection in NTUH

Level 3 mesopancreas dissection in NTUH

Level 3 mesopancreas dissection in NTUH

Level 3 mesopancreas dissection in NTUH

Compare conventional systematic mesopancreas dissection PD Conventional PD Systematic mesopancreas dissection PD Period 2015.10-12 2016.10-12 No. 34 35 Male(%) 61.7 58.3 Age(yr) 65.7 64.2 Operative time(min) 223 240 * Vascular resection(No.) 3 6 Blood loss(cc) 272 308 PDAC(%) 64.7 72.2 IPMN/IPMC(%) 25 13.9 Reoperation(No.) 1 Level I - 10 Level II 16 Level III 9

Compare conventional systematic mesopancreas dissection PD Conventional PD systematic mesopancreas dissection PD PDAC No. 12 LN exam 9.5(5-15) 13.4(11-20) * LN postive No 10 7 R1 No. 9 5 R1 site retroperitonel(7) vascular groove CBD peripancreatic tissue(2) SMA portal vein superior margin pancreatic resection Lymph-Vascular invasion 8 6 Perineural Invasion T3

Compare different level mesopancreas dissection PD Level 1 PD Level 2 PD Level 3 PD No. 10 16 9 Operative time(min) 205 245 273 * Vascular resection(No.) 3 Blood loss(cc) 270 320 Reoperation(No.) 1 PDAC rate(%) 40 56 67 ** Benign rate(%) 30 31 22

Discussion More level 3 diseection in pancreatic cancer(44/52) and PV/SMV vascular resection(32/82) More diarrhea in systematic mesopancreas dissection PDs(14/82) than conventional PDs(8/80) More opioid antidiarrheal agents use(13/14) than conventional PDs (4/8), especially level 3 (12/13) Point of SMA abutment by invasive tumor in 20 patients (Inoue, Ann Surg 2015)

Discussion (NTUH experience) Longer operative time, more vesculaer resection, more blood loss in systematic mesopancreas dissection Systematic mesopancreas dissection increase R0 resection rate and LN exam number Further study issue: Long-term survival effect Definition of level three dissection More frozen pathology exam or more precise preoperative plan Total pancreatectomy or other procedure

吳健暉、郭庭均、吳經閔、楊卿堯、田郁文 台灣大學附設醫院一般外科 Thank you 吳健暉、郭庭均、吳經閔、楊卿堯、田郁文 台灣大學附設醫院一般外科