Evaluation of Systemic Microcirculatory Vessel Density in the Early Postoperative Period of Heart Valve Surgery: an...

The present study evaluated systemic microcirculatory alterations occurring in the early postoperative period of cardiopulmonary bypass-assisted heart valve surgery compared to preoperative parameters through noninvasive point-of-care microcirculatory imaging of the sublingual area using incident dark field imaging.

This was a single-center cross-sectional observational study that included 23 patients aged 49 ± 13 years. Sublingual microcirculatory density and perfusion were evaluated using a handheld camera based on incident dark field imaging before surgery and in the early postoperative period.

The total number of capillary vessels (1029 ± 13, P=0.0006), total length of capillary vessels (29.4 ± 3.2 mm, P=0.0005), and capillary vessel density (16.8 ± 1.8 mm/mm2, P=0.0005) were all higher after surgery. On the other hand, the total number of noncapillary vessels (85 ± 34, P=0.05), total length of noncapillary vessels (1.9 ± 0.8 mm, P=0.07), and noncapillary vessel density (1.1 ± 0.5 mm/mm2, P=0.07) were similar before and after surgery. The total number of capillary vessels was higher after surgery (1109 ± 92) in patients who received milrinone infusion (P=0.002) but not in patients who did not receive milrinone (986 ± 129, P=0.05).

After cardiac valve surgery, there was an improvement in microvascular parameters concerning capillary vessels and in the total number of microvessels. Moreover, significant positive correlations were found between the use of milrinone and these parameters. The study demonstrated the usefulness of handheld cameras for bedside evaluation of the microcirculation.