Risk Factors Analysis Of Pancreatic Fistula After Pancreaticoduodenectomy And Study Of A New Method Of Pancreatogastrostomy

Objective:To analyze the risk factors of postoperative pancreatic fistula(POPF)after pancreaticoduodenectomy(PD)through newly issued definition and grading system of International Study Group of Pancreatic Surgery 2016(ISGPS 2016)and to reduce the incidence rate accordingly through applying a new method of pancreatogastrostomy.Methods:In the first phase,we collected 276 consecutive patients who underwent open pancreaticoduodenectomy between January 2009 and March 2014 in our hospital for retrospectively univariate and multivariate analysis of possible factors related to POPF.158 cases of pancreatic head carcinoma were analyzed,especially for the influence of PD combined with portal vein resection on postoperative complications including pancreatic fistula.In addition,we performed a subgroup analysis of patients undergoing pancreaticoduodenectomy for pancreatic carcinoma aged over 65 years old,and analyzed curative effect and security of portal vein resection and reconstruction among them.In the second phase,we applied a new method of pancreatogastrostomy,the inserting pancreaticogastrostomy(IPG),and retrospectively analyzed it from January 2010,the time when first applying IPG,to September 2015.A total of 309 patients undergoing open PD in the hospital were divided into pancreaticogastrostomy group(PG)and pancreaticojejunostomy group(PJ)for analysis.The incidence rates of postoperative complications,especially pancreatic fistula,were compared between two groups.The subgroup analysis was performed in the PG group and it was divided into conventional pancreaticoduodenectomy group(CPD)and pylorus-preserving pancreaticoduodenectomy(PPPD),majorly for analyzing the incidence rate of POPF.Results:Between January 2009 and March 2014,the pancreatic fistula rate among all 276 cases of PD was 15.9%(44 cases)with 26 biochemical leak(BL)cases,13 grade B cases and 5 grade C cases of pancreatic fistula.4 patients died within perioperative period and the mortality rate was 1.4%.1 of them had intra-abdominal infection after pancreatic fistula.After rejecting a re-operation,the patient died of multipale organ dysfunction syndrome(MODS).1 died of serious intra-abdominal infection after the re-operation of pancreatic fistula.1 died of acute liver failure and another died of intra-peritoneal hemorrhage.According to the univariate analysis,POPF was related with pancreatic texture,pancreatic duct size and extended resection.From the perspective of multivariate analysis,the diameter of the pancreatic duct less than 3mm and extended resection were two independent risk factors of POPF.66 cases of 98 cases(67.3%)of extended resection were excised by portal vein resection and reconstruction.No significant differences of post-operative complications rate were there between portal vein resection and reconstruction group and non-resection and reconstruction group.In the subgroup of patients over 65,the nutritional status of non-resection and reconstruction group was better than resection and reconstruction group.No significant differences were there of overall postoperative complications and survival rate.But the efractory diarrhea rate of resection and reconstruction group was higher than non-resection and reconstruction group.Among all the 309 patients undergoing PD between January 2010 and September 2015.the total pancreatic fistula rate was 20.4%.The pancreatic fistula rate in the PG group(16.4%)was significantly lower than that in the PJ group(25.8%).No significant differences of BL rate were there between two groups,yet there were significant differences of grade B and C grade pancreatic fistula.POPF rate in the PPPD group was significantly higher than the CPD group in the PG group(29.4%vs 11.9%,P=O.008).1 case died of severe pancreatic fistula in the PPPD group.Conclusion:The diameter of the pancreatic duct less than 3mm and extended resections were independent risk factors of POPF.Extended portal vein resection and reconstruction is recommended when the tumor has invaded portal vein and radical resection can be achieved,for it will not increase the POPF rate.Besides that,IPG is a safe and reliable method of pancreas digestive tract anastomosis.However,it is not recommended to preserve pylorus when applying IPG,as it will increase the incidence rate of POPF.