Evaluation of central vein sizes in patients with autogenous hemodialysis fistulas

Purpose: To quantify diameters of central vein segments in patients with autogenous hemodialysis fistulas. Materials and Methods: A retrospective review of patients within the last year who underwent arterial venous fistula assessment identified 218 patients. Of these, 32 also had computed tomography (CT) of the thorax performed from which venous sizes could be ascertained. Measurements in the axial plane (diameter) of the central veins were obtained from calibrated DICOM images. Additional demographic information including age, sex, and location of the fistula were also acquired to determine whether there was any correlation of these factors with the vein diameters. Variables were compared using the unpaired t test. Results: There were 21 and 11 patients with left-sided and right-sided fistulas, respectively, with a mean age of 61.1 years. There was no statistically significant difference (P<.05) found between the diameter when comparing men to women (P=.93 to .22) or patient ages less than or greater than 70 years old (P=.95 to .11). The only statistically significant difference observed was when the fistula was located in the left arm, with the left axillary vein being larger than the right (11.4 +/- 0.6 and 8.4 +/- 0.6 respectively P=.003). The remaining vessels showed no statistically significant difference in size with respect to the fistula location (P=.75 to .07). Conclusions: The left axillary vein is significantly larger in patients who have a fistula located in the left arm compared to the right. Central vein sizes measured by CT correlate with sizes measured angiographically in prior retrospective studies.