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

## TL;DR

This study found that microvascular density improves after heart valve surgery, with milrinone use linked to better outcomes.

## Contribution

The study demonstrates improved microvascular parameters post-surgery and the effectiveness of milrinone using noninvasive imaging.

## Key findings

- Capillary vessel density and perfusion increased significantly after surgery.
- Milrinone infusion was associated with higher capillary vessel counts post-surgery.
- Handheld cameras proved useful for noninvasive microcirculatory evaluation.

## Abstract

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.