Risk factors for postoperative pancreatic fistula: Analysis of 539 successive cases of pancreaticoduodenectomy

AIM To analyze the risk factors for pancreatic fistula after pancreaticoduodenectomy.METHODS We conducted a retrospective analysis of 539 successive cases of pancreaticoduodenectomy performed at our hospital from March 2012 to October 2015. Pancreatic fistula was diagnosed in strict accordance with the definition of pancreatic fistula from the International Study Group on Pancreatic Fistula. The risk factors for pancreatic fistula were analyzed by univariate analysis and multivariate logistic regression analysis.RESULTS A total of 269(49.9%) cases of pancreatic fistula occurred after pancreaticoduodenectomy,including 71(13.17%) cases of grade A pancreatic fistula,178(33.02%) cases of grade B,and 20(3.71%) cases of grade C. Univariate analysis showed no significant correlation between postoperative pancreatic fistula(POPF) and the following factors: age,hypertension,alcohol consumption,smoking,history of upper abdominal surgery,preoperative jaundice management,preoperative bilirubin,preoperative albumin,pancreatic duct drainage,intraoperative blood loss,operative time,intraoperative blood transfusion,Braun anastomosis,and pancreaticoduodenectomy(with or without pylorus preservation). Conversely,a significant correlation was observed between POPF and the following factors: gender(male vs female: 54.23% vs 42.35%,P = 0.008),diabetes(non-diabetic vs diabetic: 51.61% vs 39.19%,P = 0.047),body mass index(BMI)(≤ 25 vs > 25: 46.94% vs 57.82%,P = 0.024),blood glucose level(≤ 6.0 mmol/L vs > 6.0 mmol/L: 54.75% vs 41.14%,P = 0.002),pancreaticojejunal anastomosis technique(pancreatic duct-jejunum double-layer mucosa-to-mucosa pancreaticojejunal anastomosis vs pancreatic-jejunum single-layer mucosa-tomucosa anastomosis: 57.54% vs 35.46%,P = 0.000),diameter of the pancreatic duct(≤ 3 mm vs > 3 mm: 57.81% vs 38.36%,P = 0.000),and pancreatic texture(soft vs hard: 56.72% vs 29.93%,P = 0.000). Multivariate logistic regression analysis showed that gender(male),BMI > 25,pancreatic duct-jejunum double-layer mucosa-to-mucosa pancreaticojejunal anastomosis,pancreatic duct diameter ≤ 3 mm,and soft pancreas were risk factors for pancreatic fistula after pancreaticoduodenectomy.CONCLUSION Gender(male),BMI > 25,pancreatic duct-jejunum double-layer mucosa-to-mucosa pancreaticojejunal anastomosis,pancreatic duct diameter ≤ 3 mm,and soft pancreas were risk factors for pancreatic fistula after pancreaticoduodenectomy.

Integrin αvβ6 sustains and promotes tumor invasive growth in colon cancer progression

AIM: To detect the mechanism by which colon tumor escapes the growth constraints imposed on normal cells by cell crowding and dense pericellular matrices.METHODS: An immunohistochemical study of integrin αvβ6 and matrix metalloproteinase-9(MMP-9) was performed on tissue microarrays of 200 spots, including 100 cases of colon tumors. RESULTS: High immunoreactivity for αvβ6(73.7%; 28/38) and MMP-9(76.5%; 52/68) was observed in invasive tumor portions. Furthermore, the effects of integrin αvβ6 on tumor invasive growth in nude mice were detected. Tumor invasive growth and high expression of both αvβ6 and MMP-9 were only seen in tumors resulting from Wi Dr cells expressing αvβ6 in the tumorigenicity assay. Flow cytometry was applied to analyze αvβ6 expression in colon cancer Wi Dr and SW480 cells. The effects of cell density on αvβ6 expression and MMP-9 secretion were also detected by Biotrak MMP-9 activity assay and gelatin zymography assay. High cell density evidently enhanced αvβ6 expression and promoted MMP-9 secretion compared with low density. CONCLUSION: Integrin αvβ6 sustains and promotes tumor invasive growth in tumor progression via a selfperpetuating mechanism. Integrin ανβ6-mediated MMP-9 secretion facilitates pericellular matrix degradation at high cell density, which provides the basis of invasive growth.

Application of single-layer mucosa-tomucosa pancreaticojejunal anastomosis in pancreaticoduodenectomy

AIM: To investigate the simplicity, reliability, andsafety of the application of single-layer mucosa-tomucosa pancreaticojejunal anastomosis in pancreaticoduodenectomy. METHODS: A retrospective analysis was performed on the data of patients who received pancreaticoduodenectomy completed by the same surgical group between January 2011 and April 2014 in the General Hospital of the People's Liberation Army. In total, 51 cases received single-layer mucosa-to-mucosa pancreaticojejunal anastomosis and 51 cases received double-layer pancreaticojejunal anastomosis. The diagnoses of pancreatic fistula and clinically relevant pancreatic fistula after pancreaticoduodenectomy were judged strictly by the International Study Group on pancreatic fistula definition. The preoperative and intraoperative data of these two groups were compared. χ2 test and Fisher's exact test were used to analyze the incidences of pancreatic fistula, peritoneal catheterization, abdominal infection and overall complications between the single-layer anastomosis group and double-layer anastomosis group. Rank sum test were used to analyze the difference in operation time, pancreaticojejunal anastomosis time, postoperative hospitalization time, total hospitalization time and hospitalization expenses between the single-layer anastomosis group and double-layer anastomosis group.RESULTS: Patients with grade A pancreatic fistula accounted for 15.69%(8/51) vs 15.69%(8/51)(P = 1.0000), and patients with grades B and C pancreatic fistula accounted for 9.80%(5/51) vs 52.94%(27/51)(P = 0.0000) in the single-layer and double-layer anastomosis groups. Although there was no significant difference in the percentage of patients with grade A pancreatic fistula, there was a significant difference in the percentage of patients with grades B and C pancreatic fistula between the two groups. Theoperation time(220.059 ± 60.602 min vs 379.412 ± 90.761 min, P = 0.000), pancreaticojejunal anastomosis time(17.922 ± 5.145 min vs 31.333 ± 7.776 min, P = 0.000), postoperative hospitalization time(18.588 ± 5.285 d vs 26.373 ± 15.815 d, P = 0.003), total hospitalization time(25.627 ± 6.551 d vs 33.706 ± 15.899 d, P = 0.002), hospitalization expenses(116787.667 ± 31900.927 yuan vs 162788.608 ± 129732.500 yuan, P = 0.001), as well as the incidences of pancreatic fistula [13/51(25.49%) vs 35/51(68.63%), P = 0.0000], peritoneal catheterization [0/51(0%) vs 6/51(11.76%), P = 0.0354], abdominal infection [1/51(1.96%) vs 11/51(21.57%), P = 0.0021], and overall complications [21/51(41.18%) vs 37/51(72.55%), P = 0.0014] in the single-layer anastomosis group were all lower than those in the double-layer anastomosis group. CONCLUSION: Single-layer mucosa-to-mucosa pancreaticojejunal anastomosis appears to be a simple, reliable, and safe method. Use of this method could reduce the postoperative incidence of complications.