1. Nakeeb A, Pitt HA, Sohn TA, et al. Cholangiocarcinoma. A spectrum of intra- hepatic, perihilar, and distal tumors. Ann Surg. 1996;224:463e473.
2. Ebata T, Kamiya J, Nishio H, Nagasaka T, Nimura Y, Nagino M. The concept of perihilar cholangiocarcinoma is valid. Br J Surg. 2009;96:926e934.
3. DeOliveira ML, Cunningham SC, Cameron JL, et al. Cholangiocarcinoma: thirty- one-year experience with 564 patients at a single institution. Ann Surg. 2007;245:755e762.
4. Lee SG, Song GW, Hwang S, et al. Surgical treatment of hilar chol- angiocarcinoma in the new era: the Asan experience. J Hepatobiliary Pancreat Sci. 2010;17:476e489.
5. van Gulik TM, Kloek JJ, Ruys AT, et al. Multidisciplinary management of hilar cholangiocarcinoma (Klatskin tumor): extended resection is associated with improved survival. Eur J Surg Oncol. 2011;37:65e71.
6. Nagino M, Ebata T, Yokoyama Y, et al. Evolution of surgical treatment for perihilar cholangiocarcinoma: a single-center 34-year review of 574 consecu- tive resections. Ann Surg. 2013;258:129e140.
7. Jarnagin WR, Ruo L, Little SA, et al. Patterns of initial disease recurrence after resection of gallbladder carcinoma and hilar cholangiocarcinoma: implications for adjuvant therapeutic strategies. Cancer. 2003;98:1689e1700.
8. Kobayashi A, Miwa S, Nakata T, Miyagawa S. Disease recurrence patterns after R0 resection of hilar cholangiocarcinoma. Br J Surg. 2010;97:56e64.
9. Nuzzo G, Giuliante F, Ardito F, et al. Improvement in perioperative and long- term outcome after surgical treatment of hilar cholangiocarcinoma: results of an Italian multicenter analysis of 440 patients. Arch Surg. 2012;147:26e34.
10. Song SC, Choi DW, Kow AW, et al. Surgical outcomes of 230 resected hilar cholangiocarcinoma in a single centre. ANZ J Surg. 2013;83:268e274.
11. Dumitrascu T, Chirita D, Ionescu M, Popescu I. Resection for hilar chol- angiocarcinoma: analysis of prognostic factors and the impact of systemic inflammation on long-term outcome. J Gastrointest Surg. 2013;17:913e924.
12. Jung SJ, Woo SM, Park HK, et al. Patterns of initial disease recurrence after resection of biliary tract cancer. Oncology. 2012;83:83e90.
13. Groot Koerkamp B, Wiggers JK, Allen PJ, et al. Recurrence rate and pattern of perihilar cholangiocarcinoma after curative intent resection. J Am Coll Surg. 2015;221:1041e1049.
14. Komaya K, Ebata T, Yokoyama Y, et al. Recurrence after curative-intent resection of perihilar cholangiocarcinoma: analysis of a large cohort with a close postoperative follow-up approach. Surgery. 2017;163:732e738.
15. Kawashima H, Itoh A, Ohno E, et al. Preoperative endoscopic nasobiliary drainage in 164 consecutive patients with suspected perihilar chol- angiocarcinoma: a retrospective study of efficacy and risk factors related to complications. Ann Surg. 2013;257:121e127.
16. Nagino M, Kamiya J, Nishio H, Ebata T, Arai T, Nimura Y. Two hundred forty consecutive portal vein embolizations before extended hepatectomy for biliary cancer: surgical outcome and long-term follow-up. Ann Surg. 2006;243:364e372.
17. Ebata T, Yokoyama Y, Igami T, Sugawara G, Takahashi Y, Nagino M. Portal vein embolization before extended hepatectomy for biliary cancer: current tech- nique and review of 494 consecutive embolizations. Dig Surg. 2012;29:23e29.
18. Ebata T, Yokoyama Y, Igami T, et al. Hepatopancreatoduodenectomy for chol- angiocarcinoma: a single-center review of 85 consecutive patients. Ann Surg. 2012;256:297e305.
19. Nagino M, Nimura Y, Nishio H, et al. Hepatectomy with simultaneous resection of the portal vein and hepatic artery for advanced perihilar chol- angiocarcinoma: an audit of 50 consecutive cases. Ann Surg. 2010;252: 115e123.
20. Wakai T, Shirai Y, Moroda T, Yokoyama N, Hatakeyama K. Impact of ductal resection margin status on long-term survival in patients under- going resection for extrahepatic cholangiocarcinoma. Cancer. 2005;103: 1210e1216.
21. Igami T, Nagino M, Oda K, et al. Clinicopathologic study of cholangiocarcinoma with superficial spread. Ann Surg. 2009;249:296e302.
22. Zhang XF, Squires MH, Bagante F, et al. The impact of intraoperative re- resection of positive bile duct margin on clinical outcomes for hilar chol- angiocarcinoma. Ann Surg Oncol. 2018;25:1140e1149.
23. Ribero D, Amisano M, Lo Tesoriere R, Rosso S, Ferrero A, Capussotti L. Addi- tional resection of an intraoperative margin-positive proximal bile duct im- proves survival in patients with hilar cholangiocarcinoma. Ann Surg. 2011;254: 776e781.
24. Shingu Y, Ebata T, Nishio H, Igami T, Shimoyama Y, Nagino M. Clinical value of additional resection of a margin-positive proximal bile duct in hilar chol- angiocarcinoma. Surgery. 2010;147:49e56.
25. Chatelain D, Farges O, Fuks D, Trouillet N, Pruvot FR, Regimbeau JM. Assess- ment of pathology reports on hilar cholangiocarcinoma: the results of a nationwide, multicenter survey performed by the AFC-HC-2009 study group.J Hepatol. 2012;56:1121e1128.
26. Shinohara K, Ebata T, Shimoyama Y, et al. A study on radial margin status in resected perihilar cholangiocarcinoma [e-pub ahead of print]. Ann Surg. https:// doi.org/10.1097/SLA.0000000000003305. Accessed April 2, 2019.
27. Ebata T, Hirano S, Konishi M, et al. Randomized clinical trial of adjuvant gemcitabine chemotherapy versus observation in resected bile duct cancer. Br J Surg. 2018;105:192e202.
28. Takahashi Y, Ebata T, Yokoyama Y, et al. Surgery for recurrent biliary cancer: a single-center experience with 74 consecutive resections. Ann Surg. 2015;262: 121e129.
29. Groot VP, Rezaee N, Wu W, et al. Patterns, timing, and predictors of recurrence following pancreatectomy for pancreatic ductal adenocarcinoma. Ann Surg. 2018;267:936e945.
30. Lee KF, Chong CCN, Fong AKY, et al. Pattern of disease recurrence and its im- plications for postoperative surveillance after curative hepatectomy for hepa- tocellular carcinoma: experience from a single center. Hepatobiliary Surg Nutr. 2018;7:320e330.