BackgroundGastric cancer is the second highest cause of morbidity among malignant tumors of the gastrointestinal tract and fifth in overall cancer statistics. Diseases of the cardiovascular system are the leading causes of death in the world. Aneurysm of the abdominal aorta is the most common type of vascular aneurysm, while in 75% of the cases it is asymptomatic. The risk of rupture of aneurysm of the abdominal aorta increases progressively depending on its diameter and the age of the patient.Case presentationA 56-year-old male patient underwent treatment for complaints of pain and discomfort in the epigastric region, general weakness and difficulty in passing food through the esophagus. The neoplasm extended to the esophagus up to 17–20 mm (pT3N3aM0 R0 stage IIIB TNM 8). The aortic diameter at the level of the renal arteries was 18 mm; lower than the main renal arteries, an expansion of up to 60 mm was visualized; the length of aneurysm was 105 mm extending to the bifurcation. A gastrectomy with a resection of the lower thoracic esophagus and application of a manual double-row Roux-en -Y esophagojejunal anastomosis with cholecystectomy and D2 lymphadenectomy was done along with longitudinal aneurysmectomy and thrombectomy. The proximal anastomosis between the aorta and the synthetic linear prosthesis of 18 × 9 × 9 mm in the end-to-end type was formed by a continuous winding suture with the “Prolene” 5-0 thread. The end-to-end distal anastomosis of the prosthesis and aorta branch was formed by continuous winding suture with the “Prolene” 6-0 thread. The postoperative period proceeded without features and complications. On the 7th day after the surgery, the patient was discharged home in satisfactory condition.ConclusionsPerforming a simultaneous operation allowed the patient to undergo rehabilitation after the treatment of two diseases during one hospitalization and, in the shortest possible time, to proceed to the next stage of gastric cancer treatment—chemotherapy, thereby improving the prognosis of life expectancy. Also, one-stage surgical treatment of concomitant aneurysm of the abdominal aorta and gastric cancer is well tolerated and can avoid financial costs, and patient anxiety involved in a second operation.