The effect of the stream direction from an aortic-caval fistula. Experimental angiographic study on vein size.

Using a vascular prosthesis, an aortic-caval fistula was created in dogs. On healing, the prostheses became curved and in consequence the stream from the fistula in three dogs was directed to the peripheral venous limb of the fistula and in four dogs remained directed to the cardial vein. The observation periods were 1–6 months. Surgical intervention alone (implantation of the prosthetic patch graft) caused no changes in the cross-section area of the inferior vena cava. In all the dogs with aortic-caval fistula, a 1–4 cm long un-dilated area beginning from the opening of the fistula was encountered in the cardial venous limb. The greatest variations in the cross-section areas of the vein were seen in the peripheral venous limb. The peripheral vein was significantly dilated in the dogs in which the stream from the fistula was directed to it. When the stream from the fistula was directed to the cardial vein, the peripheral vein was not significantly dilated. It is assumed that even small variations in the d...