Assessment of compromised parasternal skin perfusion after left internal mammary artery harvesting with a novel laser Doppler imaging.

BACKGROUND

Our aim was to investigate the impact of the non-skeletonized (pedicled) versus the skeletonized left internal mammary (LIMA) harvesting technique on the postoperative sternal and parasternal skin perfusion in patients undergoing coronary artery bypass grafting (CABG), as compared to patients undergoing non-CABG heart surgery.

METHODS

We included 142 patients who underwent non-bypass (N.=39) or CABG surgery (N.=103). CABG cases were differentiated according to the LIMA harvesting technique: skeletonized (N.=74) or non-skeletonized (N.=29). Parasternal and sternal skin perfusion measurements via a Laser Doppler Imaging tool were performed on the preoperative day and 5-7 days postoperatively, using a grid of 15 spatially segregated measurement points across the chest and normalization to a distinct reference point. Data were analyzed retrospectively.

RESULTS

In the CABG group, the non-skeletonized LIMA harvesting resulted in a near-significant (P=0.057, two-sided Student t-test, 95% CI -[0.111, 0.002]), and the skeletonized LIMA harvesting in a significant (P< 0.001, 95% CI [-0.096, -0.032]) post-surgical decrease of left-sided parasternal skin perfusion in arbitrary perfusion units (APU), as compared to right-sided parasternal skin perfusion. No corresponding differences were found for the non-bypass group (P=0.5, 95% CI [-0.065, 0.033]). The harvesting techniques did not yield significantly different post-surgical parasternal skin perfusion measures in the CABG group (P=0.6).

CONCLUSIONS

Measurement of parasternal skin perfusion using Laser Doppler Imaging is feasible. Both harvesting techniques resulted in a reduced parasternal/sternal skin perfusion upon removal of the internal mammary artery.