Minimizing the risk of perioperative stroke by clampless off-pump bypass surgery: a retrospective observational analysis.

OBJECTIVES: Stroke is a devastating complication after coronary artery bypass grafting, occurring in 1.4% to 4.3% of patients. A major cause of stroke is cerebral embolization of aortic atheromatous debris or calcified plaques. This report analyzes the incidence of stroke in patients treated according to the clampless concept, i.e. avoiding side-clamping of the aorta, by means of off-pump coronary artery bypass surgery (OPCAB) in combination with the HEARTSTRING device. METHODS: During a period of 43 months (2005-2008), 412 consecutive patients were treated with the above-mentioned method by one single surgeon. A minimum of one proximal aortal anastomosis was performed in each patient. Altogether, 542 proximal anastomosis were applied, each created by means of the HEARTSTRING device. RESULTS: The mean age of patients was 67+9.7 years, the predicted mortality 5.2% (logistic EuroSCORE) and the observed mortality 1.9%. Histories of preoperative neurological disorders or cerebrovascular diseases were documented in 15% of patients. The overall incidence of postoperative stroke was 0.48% in contrast to 1.3% according to the stroke risk score. CONCLUSIONS: In accordance to previously published data, our results show that avoiding aortic side-clamping during OPCAB reduces postoperative stroke rates. The HEARTSTRING device is a safe option for creating proximal aortic anastomosis.

Switch from venoarterial extracorporeal membrane oxygenation to arteriovenous pumpless extracorporeal lung assist.

BACKGROUND: Extracorporeal membrane oxygenation is an effective rescue tool to treat cardiopulmonary failure. Pumpless systems treat lung failure only; they require adequate cardiac output. METHODS: We report on 18 patients initially provided with venoarterial extracorporeal membrane oxygenation and then downgraded to a pumpless arteriovenous shunt with a membrane oxygenator by removal of the pump from the circuit after hemodynamic stabilization in the face of persisting pulmonary failure. Main underlying diseases were adult respiratory distress syndrome (44%) and pneumonia (28%). Mean patient age was 44 years, and mean body mass index was 25.7 kg/m(2). Anticoagulation, hemodynamic, and respiratory variables were analyzed. RESULTS: All patients exhibited severe cardiopulmonary failure with a mean oxygenation ratio (partial pressure of oxygen to fraction of inspired oxygen ratio) of 74 +/- 43 mm Hg (mean partial pressure of oxygen, 70 +/- 33 mm Hg) and a mean partial pressure of carbon dioxide of 68 +/- 32 mm Hg despite maximal (ventilatory) conservative therapy (fraction of inspired oxygen, 0.98 +/- 0.08). Initial serum lactate was 51 +/- 43 mg/dL. The sequential organ failure assessment score averaged 11.8 +/- 2.47, and the lung injury score was 3.1 +/- 0.58. Total mechanical respiratory support was performed for a mean of 13.6 +/- 15.7 days. After 24 hours an improvement in oxygenation and a decrease in carbon dioxide was achieved with a mean partial pressure of carbon dioxide of 40 +/- 11 mm Hg (p < 0.001) and a partial pressure of oxygen of 86 +/- 26 mm Hg (p = 0.031). After 6 +/- 3 days of extracorporeal membrane oxygenation, patients were hemodynamically stabilized. Extracorporeal membrane oxygenation was downgraded to pumpless extracorporeal lung assist for another 10 +/- 15 days (range, 2 to 71 days). Twelve patients (66.7%) could be weaned, with a 30-day mortality of 55.6%. Norepinephrine dosage could be reduced significantly within 24 hours (3.2 +/- 1.8 versus 1.5 +/- 1.5 mg/h; p = 0.008). CONCLUSIONS: Respiratory support by an extracorporeal device used as last resort therapy allows rapid stabilization of patients with acute lung failure. Early replacement of extracorporeal membrane oxygenation by pumpless extracorporeal lung assist minimizes the negative side effects of extracorporeal circulation.