Effect of vitamin A injection on healing of anastomosis

Intervention 1: Intervention group: Intramuscular injection of vitamin A at a dose of 50000 international units (One milliliter) , daily, for 3 days after surgery. Intervention 2: Control group: Intramuscular injection of 1ml injectable sterile normal saline , daily , for 3 days after surgery.
Primary outcome(s): Anastomosis Leakage. Timepoint: 5 days after surgery. Method of measurement: Clinical signs including fever, biliary secretion, leukocytosis , Peritonitis and the need for reoperation.
Study Design: Randomization: Randomized, Blinding: Triple blinded, Placebo: Used, Assignment: Factorial, Purpose: Treatment, Randomization description: Persons who will be admitted to the treatment centers that qualify for inclusion will be given priority by the date of surgery of these patients, using a Randomization Lists, set by the Biostatistician, Code A or B, and They will be randomly divided into intervention and control groups, Blinding description: Vitamin A ampoules or injectable sterile normal saline will be administered by a qualified surgical resident in accordance with the Randomization Lists set by the biostatistician. The resident will not be a researcher, outcome assessor, or data analyst in the study. Nurse who dose not participate in the study will inject vitamin A ampoules or normal saline, so that the vitamin A ampoule or normal saline will be drawn into the syringe before presenting to the patient’s bedside and will be injected intramuscularly by the said nurse .Therefor