Comparison of a New Miniaturized Extracorporeal Membrane Oxygenation System With Integrated Rotary Blood Pump to a Standard System in a Porcine Model of Acute Lung Injury.

Extracorporeal membrane oxygenation (ECMO) is used for severe acute respiratory distress syndrome. However, available ECMO systems are large and not well designed for fast delivery, emergency implantation, and interhospital transfer. Therefore, a new miniaturized oxygenator with integrated rotary blood pump (ILIAS) was developed and compared with a standard ECMO system in a large animal model. Acute lung injury was induced with repeated pulmonary saline lavage in 14 pigs until PaO2 /FiO2 -ratio was <100 mm Hg with a positive-end-expiratory-pressure of 5 mbar. Pigs were assigned to the following three groups: group 1 (n = 4): control group with conventional ventilation; group 2 (n = 5): standard vv-ECMO; group 3 (n = 5): vv-ILIAS. Gas exchange, hemodynamics, hemolysis, and coagulation activation were examined over a period of 8 h. No device failed during the observation period. PaCO2 decreased from 59.40 ± 4.14 mm Hg to 48.62 ± 4.50 mm Hg after 1 h in the ILIAS group compared with an improvement of PaCO2 from 48.86 ± 7.45 to 40.10 ± 6.02 in the conventional ECMO group (P = not significant [n.s.]). ARDS-induced respiratory acidosis was controlled promptly with a pH of 7.2 ± 0.1 at baseline increasing to 7.4 ± 0.1 in both study groups after 60 min of ECMO support. Mean carbon dioxide transfer was comparable between the conventional ECMO and ILIAS (211.36 ± 78.39 mL/min vs. 219.99 ± 76.72 mL/min, P = n.s.). PaO2 /FiO2 increased from 118.4 ± 15.5 mm Hg to 179.1 ± 72.4 mm Hg in the ILIAS group compared with an improvement of oxygenation from 107.1 ± 24.9 mm Hg to 179.0 ± 45.7 mm Hg in the standard ECMO group (P = n.s.). Mean oxygen transfer was calculated with 136.09 ± 30.25 mL/min for the ILIAS and 129.05 ± 36.28 mL/min for the standard ECMO. Hemodynamic instability or significant activation of the plasmatic coagulation was not observed. However, hemolysis was significantly higher in the ILIAS group compared with the conventional ECMO. As the ILIAS prototype provided excellent gas exchange with hemodynamic stability comparable with a standard ECMO system, we believe this study serves as a proof of concept. Further development and design modifications (optimized rotation speed and surface coating of rotor) are already done and another experiment is projected to reduce hemolysis and platelet consumption for clinical application.

Massive alterations of the left internal thoracic artery late after repair for aortic coarctation.

Adhesions or unattended injury are known but are seldom reasons to prevent withdrawing the use of the left internal thoracic artery during coronary artery bypass grafting. The patient in this case report was a 68-year-old man, who had undergone repair for aortic coarctation 34 years prior to coronary artery bypass grafting. After left internal thoracic artery harvesting, a no-flow situation of the graft was present. Transection of the graft revealed massive atherosclerotic alterations. To avoid unnecessary left internal thoracic artery harvesting, preoperative imaging in terms of a left internal thoracic artery angiography during coronary angiography is mandatory. The fact of finding massive alterations decades after pressure reduction indicates that relief from shear stress is not necessarily combined with remodeling of vascular alterations.

[Video-assisted cardiac valve surgery]. / Videoskopisch assistierte Herzklappenchirurgie: Schmerzfreiheit durch Vermeidung der Thoraxspreizung bei unveränderter Ergebnisqualität.

BACKGROUND AND PURPOSE: Advances in the development of video-assisted systems for minimally invasive surgery now allow to perform cardiac surgery via a smaller anterolateral thoracotomy in order to reduce trauma, pain and improve cosmetics. In addition, due to sternal sparing, pulmonary function should improve resulting in reduced hospital stay and costs. However, only few centers worldwide abstain from spreading the ribs thus accepting considerable pain and reduced patient comfort. The minimally invasive approach described here uses a right-sided anterolateral incision (4-5 cm), a soft-tissue retractor and femorofemoral perfusion with endoclamping under continuous TEE (transesophageal echocardiography) control. It was the aim of this retrospective analysis to determine feasibility, safety and effectiveness of the method. PATIENTS AND METHODS: At the West German Heart Center Essen, 47 patients were operated using minimally invasive endoscopic techniques between January 2004 and April 2006 on the mitral valve (n = 31), mitral and tricuspid valve (n = 9), including mini-Maze procedure in two cases, as well as atrial septal defects (n = 5) and myxomas (n = 2). Mean age was 58 +/- 15.2 years (range 29-87 years), NYHA II-III, 20 patients were male. RESULTS: All but one patient survived (2.1%). Conversion to median sternotomy was necessary in three of the first twelve patients. After a mean follow-up period of 18 months all reconstructions and valves were competent, freedom from cardiac reoperation was 100%. On a visual analog scale 91% ot the patients reported no or mild postoperative pain, 96% felt they had an aesthetically pleasing scar. All but one patients would choose the same operation again. CONCLUSION: Videoscopically assisted, endoscopic cardiac surgery can be performed safely, but requires a learning curve and intense training. After evaluation of efficacy and safety it is now the authors' exclusive approach to isolated atrioventricular valve disease with an ideal pain-free and cosmetic result.