Summary &Background: Postoperative pancreatic fistula (POPF) is considered to be one of the most serious complications after Pancreaticoduodenectomy increasing costs and hospital stay. Many factors influence pancreatic leakage after PD, including sex, age, jaundice, operative time, intraoperative blood loss, pancreaticojejunal anastomotic technique, texture of the remnant pancreas, pancreatic duct size, use of somatostatin, and surgeons experience. Pancreaticojejunostomy is commonly used in the reconstruction after Pancreaticoduodenectomy, but the incidence of Postoperative pancreatic fistula remains high. Many centers started using an isolated Roux loop of jejunum for PJ to decrease the incidence of POPF. Proponents of this technique believe that diversion of bile away from the PJ minimizes pancreatic enzyme activation and reduces the risk of pancreatic fistula. Another argument in favor of using an isolated loop in PJ relies on the belief that if a pancreatic fistula forms, it will be a pure pancreatic fistula and these fistulae cause less complication when compared with a complex pancreatic fistula in which bile activates pancreatic juice with more morbidity and mortality. Objectives: to compare outcomes of isolated Roux loop pancreaticojejunostomy and single loop pancreatico jejunostomy including the primary outcomes such as the rate of POPF and the secondary outcomes such as hospital stay, time to oral feeding, associated morbidity and mortality. Patients and methods: This non-randomized controlled clinical trial was carried out in General Surgery Department of Zagazig university hospitals during the period from May 2019 to January 2022, and included 36 patients who underwent Pancreaticoduodenectomy for pancreatic head cancer and, periampullary and duodenal carcinoma. Patients were divided non-randomly into two equal groups each is 18 patients. In both groups pancreaticojejunal anastomosis was done using invagination (Dunking) method but one group of them was reconstructed by isolated loop technique (ILPJ) and the other group was reconstructed by single loop technique (SLPJ). The data were recorded including demographic data, intraoperative and postoperative data. Results: there was no statistically significant difference between isolated loop PJ group and single loop PJ group as regarding age, sex, smoking and preoperative comorbidities (p>0.05). The current study showed that there was no statistically significant difference between isolated loop PJ group and single loop PJ group as regard operative time (274.4± 33.3 min. Vs 270.6± 22.9 min) (p>0.05), intraoperative blood loss (1450± 314.9 ml Vs 1444.4± 285.4 ml) (p>0.05) and the need for blood transfusion (4.5± 1.8 units Vs 4.5± 1.1 units) (p>0.05). The incidence of pancreatic leak was comparable in both groups with no significant difference between them (11.1% in ILPJ Vs 33.3% in SLPJ) (p>0.05). Mortality related to POPF was also comparable in both groups with no fistula-related deaths in ILPJ and two fistula-related deaths in SLPJ (0% in ILPJ Vs 11.1% in SLPJ) (p>0.05). Conclusion: this study showed no significant reduction of pancreatic anastomosis leak when the isolated loop technique is performed for the construction of pancreaticojejunal anastomosis instead of the single loop technique, but there is slight improvement in fistula-related morbidity and mortality and the need for re-exploration. Also due to wide use of surgical staplers in reconstruction there is no more prolonged operative time in ILPG, so we recommend it as a safe technique for pancreaticojejunal anastomosis in patients undergoing PD. However, further randomized controlled trials should be undertaken to ascertain these findings

pancreatic fistula, Pancreaticoduodenectomy, isolated loop, single loop