New Intraoperative Techniques to Improve Advanced Aortic Root Surgery

Sammanfattning: Study I: Thirteen patients underwent a modified Ross operation in which the free-standing pulmonary autograft was supported externally by a Dacron vascular prosthetic jacket (DVPJ). The tailor-made DVPJ prevented dilatation of the neo-aortic root significantly following a median follow-up of 47 months compared to a cohort of l3 matched patients undergoing conventional Ross operation. Study II: Acute intraoperative plateletpheresis (APP) with 25% circulating platelet yield was performed in18 young adult patients undergoing Ross operation. APP in combination with 2 million units of aprotinin reduced the combined need of all blood product transfusions by 47% compared to a matched cohort of 19 patients also undergoing the Ross operation and receiving 2 million units of aprotinin alone (p=.036). Study III: Twenty patients undergoing elective open left heart surgery were de-aired alternately and prospectively either with the conventional technique, (pleural cavities unopened, dead space ventilation during cardiopulmonary bypass) or with a new de-airing technique (pleural cavities open, ventilator disconnected during cardiopulmonary bypass, staged perfusion and ventilation of lungs) The new de-airing technique significantly reduced the de-airing time (10 vs 17 minutes, p<.001) and provided significantly greater freedom from residual air emboli (p= <.001). Study IV: The new de-airing technique was modified by applying active suction in the aortic root before release of the aortic cross clamp (Lund technique). Twenty patients undergoing elective open left heart surgery were prospectively randomized to either the Lund technique or to a standardized CO2 insufflation technique. The magnitude of air emboli as observed on a transesophageal echocardiogram and the number of microembolic signals as recorded by transcranial Doppler were significantly lower with the Lund technique during the de-airing period (P=.00634) and in the first 10 minutes (p =.000377) after weaning from the cardiopulmonary bypass (CPB). The de-airing time was also significantly shorter with the Lund technique (9 vs 15 minutes, p=.001). Arterial pH during CPB was significantly lower in the CO2 group (P=.00351) despite significantly higher gas flows (P=.0398) in the oxygenator.