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Updated: Sep 25, 2026
Microsurgical Clip Obliteration of Middle Cerebral Aneurysm Using Intraoperative Flow Assessment
Published on: September 25, 2009
Failed coronary artery bypass anastomosis detected by intraoperative coronary flow measurement
B H Walpoth1, A Bosshard, B Kipfer
1Clinic for Thoracic and Cardiovascular Surgery, University of Berne, Switzerland. beat.walpoth@insel.ch
Insights
Intraoperative flow measurement of coronary grafts, particularly the left internal mammary artery (IMA), aids in early detection and correction of low flow during minimally invasive coronary bypass surgery (MIDCAB). This monitoring ensures optimal graft function post-myocardial revascularization.
Area of Science:
- Cardiovascular Surgery
- Vascular Surgery
- Surgical Technology
Background:
- Myocardial revascularization aims to restore blood flow to the heart muscle.
- Minimally invasive coronary bypass surgery (MIDCAB) offers advantages but requires precise graft assessment.
- Early detection of suboptimal graft flow is crucial for successful outcomes.
Observation:
- Transit time flowmetry was used to measure intraoperative flow in arterial (left internal mammary artery - IMA) and venous coronary grafts.
- Initial low flow and high resistance were observed in IMA grafts to the left anterior descending artery (LAD).
- Manual assessment of IMA grafts did not reveal technical issues initially.
Findings:
- Re-exploration and pharmacological treatment (papaverine/adenosine) significantly improved IMA graft flow and coronary flow reserve (CFR).
- IMA grafts demonstrated improved flow from 0-1 ml/min to 26 ml/min (CFR=3.7) and 46 ml/min (CFR=3.3) after intervention.
- Intraoperative flow assessment identified and facilitated correction of previously undetected graft dysfunction.
Implications:
- Intraoperative flow monitoring of coronary grafts is recommended, especially for MIDCAB procedures.
- This technique allows for immediate technical problem-solving, enhancing graft patency.
- Improved graft flow assessment can lead to better long-term outcomes for patients undergoing myocardial revascularization.
Objectives:
To assess intraoperative flow of arterial and venous coronary grafts after myocardial revascularization which may allow early detection of low flow situations, especially during minimally invasive coronary bypass surgery (MIDCAB), and lead to immediate correction of technical problems.
Methods:
In two patients with severe and diffuse multi-vessel disease the left internal mammary artery (IMA) was connected to the left anterior descending artery (LAD). During reperfusion, the flow was measured in the IMA and vein grafts using a transit time flow meter.
Results:
In both cases the IMA showed only a systolic pendulating flow curve with a mean flow of 0-1 ml/min and a high resistance. Manual IMA assessment revealed an adequate pulsation. Both distal IMA anastomoses were re-explored on cardiopulmonary bypass yielding an initial flow of 7 and 14 ml/min, respectively. After treatment with papaverine/adenosine the IMA flow increased from 7 to 26 ml/min (coronary flow reserve (CFR) = 3.7) and from 14 to 46 ml/min (CFR = 3.3), respectively.
Conclusion:
Intraoperative flow assessment of IMA and venous bypass grafts can be recommended to monitor flow; especially during MIDCAB procedures.
