Left innominate vein stenosis in an asymptomatic population: a retrospective analysis of 212 cases.

BACKGROUND: Although left innominate vein (LIV) stenosis has been demonstrated to be attributed to compression by adjacent anatomical structures, most of the studies are focusing on hemodialysis patients with clinical symptoms compatible with LIV stenosis. The goal of this study was to retrospectively investigate the incidence of LIV stenosis and its influencing factors in an asymptomatic, non-hemodialysis population, which has rarely been performed.

METHODS: From Jan 2013 to Dec 2014, 212 consecutive cases undergoing a chest multi-detector computed tomography (MDCT) angiography were enrolled. LIV stenosis was defined as loss of the area of the LIV (that is, 1 - compression degree) >25%. Multivariate logistic regression analysis was performed to explore the independent risk factors associated with LIV stenosis.

RESULTS: LIV stenosis occurred in 35.4% of cases (75/212), with the median loss of the area of the LIV of 36.2% (interquartile range 30.2-49.8%). There were significant differences in age (62.5 ± 11.7 vs. 58.6 ± 14.3 years; P = 0.041), BMI (23.9 ± 2.9 vs. 23.0 ± 3.3, P = 0.036), the frequency of crossing site of LIV over the origin of the aortic arch (54.7 vs. 24.8%, P < 0.001), and the space between aortic arch and sternum [mean ± SD, 11.6 ± 4.2 mm vs. median, 14.1 (interquartile range 11.9-16.3) mm, P < 0.001] between patients with and without LIV stenosis, but only the latter two were confirmed as independent factors by the multivariate logistic regression analysis [crossing site of LIV over the aortic arch, OR (95% CI) = 2.632 (1.401, 4.944), P = 0.003; space between the aortic arch and sternum, OR (95% CI) = 0.841 (0.770, 0.919), P < 0.001].

CONCLUSION: The patients with an older age, high BMI, LIV crossing over the origin of the aortic arch, or smaller space between aortic arch and sternum may have high risks for LIV stenosis. They should be paid more attention to exclude LIV stenosis preoperatively using MDCT angiography to prevent venous access dysfunction and symptomatic development by fistula creation when hemodialysis is required.