Analysis of the territorial pattern of the azygos venous system and its variations in fixed cadavers

The azygos system has a wide range of anatomical variations and its knowledge is essential for anatomists, thoracic surgeons and radiologists. Thus, the aim of this study was to analyze the main anatomical variations of the azygos system in the main anatomy textbooks available in the literature and in embalmed cadavers. 14 anatomy books available in the literature and 13 embalmed cadavers and previously dissected were analyzed. The data collected both in the literature and in the embalmed cadavers demonstrated that the veins of the azygos system have many variations of origin, course, number of tributaries, anastomoses and termination. Such variations are extremely relevant from a surgical and radiological point of view. The results found will contribute to the education and training of professionals and students in addition to supporting future research. •The azygos system have variations of origin, course, number of tributaries, anastomoses and termination.•Asymptomatic variations of the azygos system.•Clinically relevant variations from a surgical and radiological point of view.