Navin Gnanasekaran1, Arunkumar Neelakandan2, Selvakumar Subbaraman3, Thambidurai Lasya4
The study was undertaken with a view to determine various inferior vena cava (IVC) parameters such as diameter in inspiration, in expiration, the mean diameter, and the collapsibility index using transabdominal ultrasound (TAS), and thus define the normal range of values for Indian population and derive nomogram values. The study was also undertaken to highlight the variations in the IVC parameters in accordance with various determinants such as age, gender, height, weight, body surface area and body mass index in the study group.
105 patients comprising of healthy Indian subjects were included in the study. The hepatic portion of the IVC was scanned with ultrasound in axial cross section. The anteroposterior diameter was measured in maximum inspiration and expiration placing the callipers from "inner to inner" wall. The mean diameter and the collapsibility index were then calculated. The resultant data was analysed using student's t test, t test and ANOVA. A 'p value' of less than 0.05 was considered significant.
Males had significantly higher collapsibility index than the females. Maximal IVC diameters were found in males in the age group of 21 to 30 years, and this was statistically significant with respect to mean IVC diameter and IVC diameter on expiration. In general, across all age groups, the IVC diameter in males was found to be higher. IVC parameters did not show any statistically significant variations with changes in the body surface area or body mass index.
TAS is a reliable, cost effective modality to monitor and measure IVC parameters. Variations in IVC parameters across age, gender, height, weight, etc. have been documented. "Nomogram chart of IVC parameters" has been derived for the Indian population and may serve as a standing reference.