A Study of Anatomical Compatibility of VAD Using Mahalanobis Distance

Abstract

Body surface area (BSA) is currently used as a standard to determine the anatomical compatibility of a patient with a ventricular assist device (VAD). However, it is difficult to accurately evaluate that of the patient with the threshold limit value of BSA to implant VAD because BSA is only calculated by the patient's height and weight. The purpose of this study is to establish a new quantitative standard which is more accurate than BSA. The parameters which represent anatomical characteristics of chest and abdomen were measured using CT images of 27 subjects. The 17 subjects with BSA of not less than 1.7 were defined as the control group assuming that the threshold limit value of BSA is 1.4. Mahalanobis distance (MD) between the 10 test subjects with BSA of not over 1.5 and the control group were calculated by means of the parameters. MD of the test subjects with BSA from 1.4 to 1.5 ranged from 2 to 44. It is confirmed that the subjects with large MD have incompatible anatomical characteristics to implant VAD in comparison with the subjects with small MD. Results suggested that MD may be able to become a new quantitative index more accurate than BSA.