Decreasing sternum microcirculation after harvesting the internal thoracic artery

Area of Science:

• Cardiovascular Surgery
• Thoracic Surgery
• Surgical Research

Background:

• Internal thoracic artery (ITA) harvesting is a common procedure in coronary artery bypass grafting (CABG).
• The impact of ITA harvesting on sternal blood supply and microcirculation remains incompletely understood.
• Maintaining sternal viability is crucial for preventing complications like sternal dehiscence and infection.

Purpose of the Study:

• To evaluate the effect of ITA harvesting on sternal microcirculation using a novel laser Doppler flow meter.
• To compare the impact of skeletonized versus pedicled ITA harvesting techniques on sternal blood supply.
• To assess changes in presternal and retrosternal blood flow at different sternal levels.

Main Methods:

• A prospective study involving 46 patients undergoing CABG, divided into skeletonized (n=23) and pedicled (n=23) left ITA groups.
• Right ITA were harvested using the skeletonized method.
• Sternal blood flow was measured using a novel laser Doppler flow meter (1-mm depth, 780-nm laser) at presternal and retrosternal sites (upper, middle, lower) before and after ITA harvesting.

Main Results:

• A significant decrease in retrosternal microcirculation was observed in the middle sternal region across all patients (p < 0.05).
• No significant changes in blood flow were noted in other sternal regions or presternal areas.
• Both skeletonized and pedicled left ITA harvesting resulted in decreased middle retrosternal blood flow, with no significant difference between the techniques. Right ITA harvesting also affected middle and lower retrosternal flow.

Conclusions:

• ITA harvesting negatively impacts sternal microcirculation, specifically in the retrosternal middle section.
• The skeletonized harvesting technique offers no discernible advantage over the pedicled technique in preserving sternal microcirculation.
• Further research may explore strategies to mitigate sternal hypoperfusion following ITA harvesting.