Christoph H. Schmitz

Transit time flow measurement in on-pump and off-pump coronary artery surgery

OBJECTIVE Transit time flow measurement is frequently used during coronary artery bypass with and without cardiopulmonary bypass to detect graft dysfunction resulting from technical errors. METHODS Intraoperative transit time flow measurement measurements of 896 patients requiring surgery for double- or triple-vessel disease were reviewed retrospectively. Six-hundred and ninety-five patients were operated on-pump (Group A: coronary artery bypass with cardiopulmonary bypass), and 201 patients off-pump (Group B: coronary artery bypass without cardiopulmonary bypass). Transit time flow measurement measurements were analyzed for mean flow (mL/min). In total, measurements of 2247 grafts were analyzed. RESULTS Transit time flow measurement flows were lower in coronary artery bypass without cardiopulmonary bypass patients (left internal thoracic artery to left anterior descending artery: Group A, 37 [31, 40] mL/min vs Group B, 24 [20, 26] mL/min; saphenous vein graft to left anterior descending artery: Group A, 46.5 [40, 56] mL/min vs Group B, 21 [14, 57] mL/min. Troponin I release was reduced in the coronary artery bypass without cardiopulmonary bypass patients, with median values of 7.8 [7.0, 8.3] microg/L in Group A and 1.2 [0.9, 2.3] microg/L in Group B. CONCLUSION Evaluation of transit time flow measurement is valuable in determining coronary graft patency after coronary artery bypass with cardiopulmonary bypass and coronary artery bypass without cardiopulmonary bypass. Decreased troponin I release suggests a myocardial benefit of coronary artery bypass without cardiopulmonary bypass compared to coronary artery bypass with cardiopulmonary bypass, although the intraoperative transit time flow measurement flow measurements are markedly lower.

Micro-Coil-Embolisierung einer Fistel des Ramus circumflexus in den Sinus coronarius Fallbericht, Differentialtherapie und Literaturübersicht

A 45 year old male suffered from typical exercise-induced dyspnoea and angina. Crohn‘s disease treated with glucocorticoids was present for 18 years. Coronary angiography revealed small left anterior descending and right coronary arteries without reference to coronary artery disease, while the main stem and circumflex artery were severely dilated due to a fistula (diameter 5.5 mm) into the coronary sinus with a left/right shunt amounting to 35%. Haemodynamics, significant risk of endocarditis with chronic inflammatory bowel disease and obligatory glucocorticoid treatment were indications for fistula closure. As an alternative to surgical correction, the coronary fistula was totally occluded by antegrade micro-coil embolization. The present report offers a review on differential therapeutic considerations and specific treatment options including novel interventional modalities for coronary fistulas. Ein 45-jähriger Patient entwickelte typische belastungsinduzierte Dyspnoe und Angina pectoris. Seit 18 Jahren bestand ein M. Crohn mit Glukokortikoid-Medikation. Koronarangiographisch stellten sich Ramus interventricularis anterior und rechte Kranzarterie klein und ohne Hinweis auf eine koronare Herzerkrankung dar, während Hauptstamm und Ramus circumflexus aufgrund einer Fistelbildung (Diameter 5,5 mm) in den Sinus coronarius massiv dilatiert waren mit einem Links/Rechts-Shunt von 35%. Hämodynamik, erhöhtes Endokarditisrisiko bei chronisch-entzündlicher Darmerkrankung und Glukokortikoid-Pflichtigkeit waren Indikation für den Fistelverschluss. Als Alternative zur chirurgischen Korrektur wurde die Koronarfistel mittels antegrader Embolisierung mit Micro-Coils komplett verschlossen. Die vorliegende Arbeit gibt einen Überblick über differentialtherapeutische Abwägungen und spezifische Behandlungsoptionen einschließlich neuer interventioneller Verfahren bei koronaren Fistelbildungen.

Simulation and planning of minimally invasive coronary artery bypass surgery

Abstract Minimally invasive coronary artery bypass surgery needs careful planning, as the spatial range is much more restricted than in conventional approaches. We have developed the first steps towards a simulation and planning system for these procedures. Our approach is based on registering a virtual heart model to CT images of the patient. Such a model can embed empirical parameters about the intraoperative movement of elastic tissue to provide estimates for the motion range of target markers.