John M. Murkin

Simultaneous integrated coronary artery revascularization with long-term angiographic follow-up

OBJECTIVE Traditionally integrated coronary artery revascularization has been described as a 2-stage procedure. We evaluated the safety and feasibility of 1-stage, simultaneous, hybrid, robotically assisted coronary artery bypass grafting surgery and percutaneous coronary intervention. METHODS Fifty-eight patients underwent simultaneous, integrated coronary artery revascularization in an operating theater equipped with angiographic equipment. Forty-five patients were men. The mean age was 59 years. All internal thoracic arteries were harvested with robotic assistance. All anastomoses were manually constructed through a small anterior non-rib-spreading incision without cardiopulmonary bypass on the beating heart. Immediately after and within the same operative suite, both angiographic confirmation of graft patency and percutaneous coronary intervention were performed. In 52 patients therapeutic anticoagulation was achieved with the direct thrombin inhibitor bivalirudin. RESULTS There were no deaths or wound infections. There was 1 perioperative myocardial infarction. One patient had a stroke, and 3 patients required re-exploration for bleeding. The median lengths of intensive care and hospital stay were 1 and 4 days, respectively. All patients were alive and symptom free at follow-up (mean, 20.2 months; range, 1.1-40.8 months). Long-term angiographic follow-up in 54 patients showed 49 (91%) patent grafts (mean, 9.0 months; range, 4.3-40.8 months). There were 7 in-stent restenoses and 2 occluded stents. CONCLUSION For multivessel coronary artery disease, simultaneous integrated coronary artery revascularization with bivalirudin is safe and feasible. This approach enables complete multivessel revascularization with decreased surgical trauma and postoperative morbidity. Further studies are necessary to better determine patient selection and long-term outcomes.

Rate of change of cerebral blood flow velocity with hyperventilation during anesthesia in humans.

Purpose: Although it has been suggested that the rate at which the cerebral circulation responds to changes in PaCO2 is different with differing anesthetics, there have been no attempts to measure this. Transcranial Doppler allows the continuous measurement of cerebral blood flow velocity (CBFV) and any changes over time. Our aim was to compare the rate of change of CBFV when end-tidal CO2 (PETCO2) was rapidly altered during halothane or isoflurane anesthesia.Methods: Twenty-eight unpremedicated healthy patients were randomly assigned to receive air/O2 and either 1 – 1.5 MAC halothane or isoflurane as the primary anesthetic. After 15 min of steady state, PETCO2 was rapidly reduced from 45 mmHg to 30 mmHg. CBFV and PETCO2 were recorded every 30 sec for the next 10 min.Results: The rate of change of normalized CBFV (Δ CBFVvs Δ time) was more rapid in the isoflurane group (P<0.0001) especially in the initial few minutes. In all patients anesthetized with isoflurane, and in all but two patients anesthetized with halothane, the reduction in PETCO2 produced a corresponding decrease in CBFV. However, there were no differences in the magnitude of cerebrovascular CO2 reactivity (Δ CBFVvs Δ PETCO2) between the two groups.Conclusions: The rate of change of CBFV was faster in the isoflurane than in the halothane group especially in the initial few minutes. Indeed, for two patients in the halothane group Vmca did not change despite a change in PETCO2. This may be of clinical importance when cerebrovascular tone needs to be changed rapidly.RésuméObjectif: Bien qu’on ait suggéré que la vitesse à laquelle la circulation cérébrale répondant aux changements de PaCO2, varie selon le type d’anesthésique, aucun essai ne l’a mesurée. Le Doppler transcrânien permet la mesure continue de la vitesse du flux sanguin cérébral (VFSC) pour chaque changement dans le temps. Notre but était de comparer la vitesse de changement de la VFSC quand le CO2 de fin d’expiration (la PETCO2) était modifié rapidement pendant l’anesthésie à l’halothane ou à l’isoflurane.Méthode: Vingt-huit patients en santé, sans prémédication, ont été répartis au hasard et ont reçu un mélange air/O2 et 1 – 1,5 CAM d’halothane ou d’isoflurane comme principal anesthésique. Après 15 min de stabilité, la PETCO2 a été réduite rapidement de 45 mmHg à 30 mmHg. La VFSC et la PETCO2 ont été enregistrées toutes les 30 s pendant les 10 min suivantes.Résultats: La vitesse de changement de la VFSC normalisée (Δ VFSCvs Δ temps) a été plus rapide avec l’isoflurane (P<0,0001) surtout pendant les premières minutes. Chez tous les patients anesthésiés avec l’isoflurane, et chez tous sauf deux patients anesthésiés avec l’halothane, la réduction de la PETCO2 a entraîné une baisse correspondante de la VFSC. Toutefois, il n’y a pas eu de différence intergroupe quant à la réactivité du CO2 cérébrovasculaire (Δ VFSCvs Δ PETCO2).Conclusion: Le changement de la VFSC a été plus rapide avec l’isoflurane qu’avec l’halothane, surtout pendant les premières minutes. Il est à noter que pour deux patients qui ont reçu l’halothane, la VFSC n’a pas changé malgré une modification de la PETCO2. Cette constatation a des répercussions cliniques, quand le tonus cérébrovasculaire doit être rapidement modifié.