Summary
The present investigation attempts to correlate flow measurements made intraoperatively in coronary bypass grafts with clinical outcome.
A total of 352 consocutive paticnts undergoing isolated coronary artery surgery underwent hemodynamic assessment of their bypass grafts (328 internal thoracic artery and 582 saphenous vein grafts) at the end of cardiopulmonary bypass (CPB) by using a 8 MHz pulsed Doppler ultrasound flowmeter. The total patient population was divided into three groups of distinct outcome (A: normal, 228 patients; B: complicated, 106 patients; C: poor, 18 patients) on the basis of a combination of the following parameters: difficult weaning from bypass, use of inotropic drugs, reduced left-ventricular stroke work index, myocardial infarction, intraaortic balloon counterpulsation, and death of cardiac origin.
Univariate analysis has shown clinical outcome to be influenced by preoperative clinical condition and not by flow in bypass grafts (average flow per graft [ml/min] was 60 ± 2 [mean ± SEM) in group A, 58 ± 3 in group B and 43 ± 6 in group C: NS by analysis of variance). Multivariate analysis (Fisher linear discriminant analysis) selected only the two following factors leading to normal (group A) or adverse (groups B and C) outcome: unstable angina (p = 0.026) and duration of additional CPB after unclamping the aorta (p< 10-5 ).
To conclude, clinical outcome was not influenced by flow as measured in well-functioning bypass grafts by pulsed Doppler technique.
Zusammenfassung
In der vorliegenden Untersuchung sollte geklärt werden, ob zwischen intraoperativ gemessenen Flußwerten in Bypass-Gefäßen und den postoperativen Ergebnissenein Zusammen hang besteht.
Bei 352 Patienten mit isolierten koronarchirurgischen Eingriffen (328 art. thoracia interna und 582 ven. saphena magna) wurde nach Beendigung der extrakorporalen Zirkulation (EZK) der Bypass-Fluß mittels eines 8 MHz gepulstem Doppler-Flowmeters gemessen. Das Gesamt-Patienten-Kollektiv wurde entsprechend dem postoperativen Ergebnis (A: normal, 228 Patienten; B: kompliziert, 106 Patienten; C: schlecht, 18 Patienten) basierend auf der Kombination folgender Parameter eingeteilt: schwierige Beendigung der EKZ, Bedarf an inotropen Substanzen, verminderter linksventrikulärer “stroke work index”, Myokardinfarkt, IABP und kardiale Todesursachen.
Die univariate Analyse der Daten zeigte, daß das postoperative Ergebnis vom präoperativen Zustand der Patienten und nicht vom Blutfluß im Bypass beeinflußt wird. Der mittlere Blutfluß pro Bypass (ml/min) betrug 60 ± 2 (mittel ± SEM) in Gruppe A, 58 ± 3 in Gruppe B und 43 ± 6 in Gruppe C (NS).
Key words
Myocardial revascularization - Risk factors - Doppler ultrasound flow measurements - Internal mammary arteries
