Seife,Henok(Consultant General and HPB surgeon)Embiale,Nebiat2026-06-222026-06-222025-07https://etd.aau.edu.et/handle/123456789/8416Background: Segment 3 bypass surgery, which was once the most commonly done procedure, is the construction of biliary enteric anastomosis between segment 3 intrahepatic bile duct and proximal jejunum. Mostly it is done as palliative treatment for Malignant Hilar Biliary Obstruction (MHBO). This procedure has been done worldwide starting from the early 20th century but rarely being done nowadays. The 30- day perioperative mortality of this procedure falls in the range between 0-31%. There is no study in Ethiopia, to the best of author knowledge, assessing clinical profile and 30- day perioperative outcome of segment III bypass surgery. Objectives: The objective of this study was to assess thirty-day perioperative outcomes (effectiveness, morbidity, mortality, complication rates) of patients after Segment 3 bypass surgery and its contributing factors after bypass surgery. Method: Multicenter retrospective cohort study was conducted in Addis Ababa, Ethiopia. Data was collected from medical records of patients with a structured questionnaire and data was entered into SPSS version 27. Descriptive analysis and non-parametric dependent (Wilcoxon) related sample test were done to know the effect of bypass surgery on liver enzymes and serum bilirubin level. Variables with P-value less than 0.05 were considered to know and declare the effect size of bypass surgery. Result: A total of 35 cases has undergone segment III bypass surgery from January 2020 to December 2024. Out of these it was possible to retrieve the data of 25 cases and 2 of the cases were having incomplete data and were not included in the analysis. The mean age of the patients was 52.87 years. More than half of (56.5%) the cases were males. Hilar cholangiocarcinoma accounts for the majority (78.3%) of causes for hilar biliary obstruction followed by gallbladder cancer. The median duration of surgery was 180.0 (70.0) minutes and the median intraoperative bleeding was around 700.0 (600.0) ml. Three patients (13.0%) patients were died within 30-day of operation and 4 (17.4%) patients developed allover morbidity rate within 30 days of operation. Serum bilirubin and ALP level significantly dropped after the bypass surgery (z=3.724 p= <0.001 and z= 2.659 p=0.008 respectively). Only 1 (4.3) patient developed major complication requiring re operation. The common surgical complications identified were bile leak, surgical site infection, and bleeding. Conclusion: Segment III bypass surgery gives effective palliation of cholestatic symptoms with acceptable 30-day perioperative mortality and morbidity rate.en-USSegment III bypass surgeryperioperative outcomeEthiopia.Thesis