Proposed Chaoyang vascular classification for superior mesenteric-portal vein invasion, resection, and reconstruction in patients with pancreatic head cancer during pancreaticoduodenectomy - A retrospective cohort study

Background: Patients with pancreatic head cancer involving the superior mesenteric-portal vein can benefit from vascular resection and reconstruction. We aimed to propose our vascular classification and assess its effect in this study. Material and methods: Data of consecutive patients, who were diagnosed with pancreatic head cancer, and underwent radical pancreaticoduodenectomy combined with superior mesenteric-portal vein resection and reconstruction at our institute between October 2013 and August 2016, were retrospectively collected. On a scale of one to four, our classification was proposed. Perioperative parameters were then analyzed among the four types. Results: There were a total of 52 patients with 11 in type I, 15 in type II, 18 in type III, 8 in type IV. The respective operative time and estimated blood loss of types III (425-990 min, 265-1820 mL) and IV (480-1036 min, 330-1690 mL) were greater than those of types I (300-824 min, 200-1255 mL) and II (369-875 min, 305-1400 mL) (p < 0.05). Type IV had larger tumors (4-7 cm) than type I (1.5-4 cm) (p < 0.05). Percentage of tunica intima involvement and the median survival time of type I (9.1%, 22 months) were lower and longer than those of types II (46.7%, 17 months) and III (44.4%, 16 months; p < 0.05), and even lower and longer than those of type IV (87.5%, 10 months; p < 0.01), respectively. Conclusions: Our classification can provide a system to grade patients with venous invasion in order of surgical difficulty and survival.