The role of ultrasonography in determining central venous patency in patients undergoing bowel transplantation

Ultrasonography (US) is an attractive alternative for invasive studies to evaluate venous patency. However, little data exist concerning the usefulness of US in patients undergoing bowel transplantation. Twenty-five adult patients with bowel transplantation were retrospectively identified with both US and contrast venography (VG) performed preoperatively. The median age was 43yr, and the median duration of total parenteral nutrition was 36months. The vessels were evaluated as positive with ≥50% stenosis. Among the internal jugular veins and the subclavian veins examined with US (96% of the all sites) and with VG (69%), 66 venous sites were available for comparison. VG confirmed positive in 42% (28/66), while US found positive in 27% (18/66); US had three false positives and 13 false negatives, giving the sensitivity of 54% (95% confidence interval [CI], 34-72) and the specificity of 92% (CI, 77-98). The positive and the negative likelihood ratios weighted by prevalence (42%) were 5 (CI, 1.7-14.3) and 0.37 (CI, 0.23-0.60), respectively. In addition, VG confirmed stenosis in 32% of the right and 50% of the left brachiocephalic veins and 41% of the superior vena cava. US is not a reliable method for assessing the upper body venous system of patients undergoing bowel transplantation.