Minimally invasive mitral valve surgery is associated with a low rate of complications.

Minimally invasive mitral valve surgery is generally performed through a right minithoracotomy, in contrast to the traditional full median sternotomy approach. Minimally invasive mitral valve surgery is performed with increasing frequency, and by reducing surgical trauma, several observational studies suggest potential benefits with decreased bleeding and postoperative pain, reduced incidence of sternal wound infections, reduced length of hospital stay and shortened recovery period after surgery. In this review, we present an overview of mitral valve surgery, summarize the available evidence regarding the minimally invasive approach and report our experiences from introducing a minimally invasive mitral valve surgery programme at the Karolinska University Hospital in Stockholm, Sweden.

Does CO(2) flushing of the empty CPB circuit decrease the number of gaseous emboli in the prime?

Twenty (20) CPB-circuits were randomized to a CO(2) group or a control group. In the CO( 2) group, each circuit was flushed with CO(2) (10L/min) at the top of the venous reservoir for 5 minutes, after which priming fluid was added without interruption of the CO(2) inflow. Control group circuits were not flushed and contained air. A perfusionist, blinded to the study, started the pump (5L/min), ventilated the oxygenator (3L O(2)/min), and knocked on the oxygenator 20 times during the first and 14(th) minutes. Arterial line microemboli counts were registered with a Doppler for 15 minutes. In both groups, the median number of microemboli was highest during the first minute, 380.5 (288.75/422.25, 25(th)/75(th) percentile) counts in the control group versus 264.5 (171.75/422.25) counts in the CO( 2) group (p=0.01). Throughout the experiment, the median microembolic count minute by minute in the CO(2) group remained lower (p < or = 0 .004) than in the control group. Knocking on the reservoir (14(th) minute) increased the microemboli counts in both groups (p<0.01). The median values during the 15(th) minute were 15.5 and 0.5 in the control and the CO(2) groups, respectively, which were 9% (15.5/173) and 0.5% (0.5/87), respectively, of the values registered after 14 minutes. In conclusion, CO( 2) flushing of the empty circuit decreases the number of gaseous emboli in the prime compared with a conventional circuit that contains air before being primed with fluid. Knocking of the oxygenator releases gaseous emboli and the duration of re-circulating the circuit with prime influences the number of microemboli.

Long-term survival after surgery for acute coronary syndromes in relation to perioperative troponin T release and angina class - a prospective study in 200 patients.

OBJECTIVE: Patients with acute coronary syndrome have an increased risk of cardiac death or myocardial infarction after urgent coronary artery bypass surgery (CABG). Symptoms and signs of ongoing ischemia, such as elevated cardiac troponin T and angina at rest at the time of the operation identify patients at particular risk of early death, but the impact of these parameters on long-term survival is poorly investigated. METHODS: Two hundred patients, 100 with acute coronary syndrome and 100 with stable angina pectoris, underwent primary isolated CABG. Troponin T levels were assayed immediately before the operation and at 64 hours after the aortic cross-clamp had been removed. The severity of the patients' unstable symptoms was classified according to Braunwald. Early outcome and long-term survival were analyzed. RESULTS: Among the unstable patients 3 deaths occurred within 30 days of the operation, and there were 12 late deaths. In the control group there were no early and 19 late deaths. The patients were followed up for 6.5 years (0-7.7 years), a total of 1 294 patient years. The cumulative long-term survival was 85 % for the unstable and 81 % for the stable patients ( P = 0.75). Freedom from cardiac death was 92 % in unstable and 94 % in stable patients. Five unstable and one of the stable patients suffered postoperative myocardial infarction ( P = 0.01). A troponin T level > 0.1 microg/L immediately prior to the operation was associated with an increased need for postoperative pharmacological inotropic support ( P < 0.001) and intra-aortic balloon counterpulsation ( P = 0.004). Symptoms and signs of ongoing ischemia (angina at rest and elevated troponin T immediately prior to the operation) had no predictive value for long-term survival. CONCLUSION: In patients with acute coronary syndrome, parameters such as elevated troponin T and angina at rest herald an increased risk of postoperative myocardial infarction and indicate the need for pharmacological and mechanical inotropic support but have no bearing on long-term survival.

Carbon dioxide inhibits the growth rate of Staphylococcus aureus at body temperature.

BACKGROUND: Since the 1930s, carbon dioxide (CO(2)) has been combined with cold storage for the preservation of food. However, its use for the prevention of surgical wound infection was long considered to be impractical. Now CO(2) is widely used during laparoscopic procedures, and a method has been developed to create a CO(2) atmosphere in an open wound. The aim of this study was to investigate the effect of CO(2) on the growth of Staphylococcus aureus at body temperature. METHODS: First, S. aureus inoculated on blood agar were exposed to pure CO(2) (100%), standard anaerobic gas (5% CO(2), 10% hydrogen, 85% nitrogen), or air at 37 degrees C for a period of 24 h; then a viable count of the bacteria was made. Second, S. aureus inoculated in brain-heart infusion broth and kept at 37 degrees C were exposed to CO(2) or air for 0, 2, 4, 6, and 8 h; then the optical density of the bacteria was measured. RESULTS: After 24 h, the number of S. aureus on blood agar was about 100 times lower in CO(2) than in anaerobic gas (p = 0.001) and about 1,000 times lower than in air (p = 0.001). Also, in broth, there were fewer bacteria with CO(2) than with air (p < 0.01). After 2 h, the number of bacteria was increased with air (p < 0.001) but not with CO(2) (p = 0.13). After 8 h, the optical density had increased from zero to 1.2 with air but it had increased only to 0.01 with CO(2) (p = 0.001). CONCLUSION: Pure CO(2) significantly decreased the growth rate of S. aureus at body temperature. The inhibitory effect of CO(2) increased exponentially with time. Its bacteriostatic effect may help to explain the low infection rates in patients who undergo laparoscopic procedures.

Effect of CO2 insufflation on the number and behavior of air microemboli in open-heart surgery: a randomized clinical trial.

BACKGROUND: The risks that the presence of air microemboli implies in open-heart surgery have recently been emphasized by reports that their number is correlated with the degree of postoperative neuropsychological disorder. Therefore, we studied the effect of CO2 insufflation into the cardiothoracic wound on the incidence and behavior of microemboli in the heart and ascending aorta. METHODS AND RESULTS: Twenty patients undergoing single-valve surgery were randomly divided into 2 groups. Ten patients were insufflated with CO2 via a gas diffuser, and 10 were not. Microemboli were ascertained by intraoperative transesophageal echocardiography (TEE) and recorded on videotape from the moment that the aortic cross-clamp was released until 20 minutes after end of cardiopulmonary bypass (CPB). The surgeon performed standard de-airing maneuvers without being aware of TEE findings. Postoperatively, a blinded assessor determined the maximal number of gas emboli during each consecutive minute in the left atrium, left ventricle, and ascending aorta. The 2 groups did not differ in the usual clinical parameters. The median number of microemboli registered during the whole study period was 161 in the CO2 group versus 723 in the control group (P<0.001). Corresponding numbers for the left atrium were 69 versus 340 (P<0.001), left ventricle 68 versus 254 (P<0.001), and ascending aorta 56 versus 185 (P<0.001). In the CO2 group, the median number of detectable microemboli after CPB fell to zero 7 minutes after CPB versus 19 minutes in the control group (P<0.001). CONCLUSIONS: Insufflation of CO2 into the thoracic wound markedly decreases the incidence of microemboli.

[Electrical conversion of atrial fibrillation. Superior effects of biphasic transthoracic method when compared with the conventional monophasic method]. / Elektrisk konvertering av förmaksflimmer. Bifasisk transtorakal metod överlägsen konventionell monofasisk.

Can biphasic electrical conversion of atrial fibrillation replace the standard monophasic method? This report reviews factors facilitating the electrical conversion of atrial fibrillation and describes a clinical trial, showing superior effects of biphasic versus monophasic electrical conversion of atrial fibrillation. We conclude that the most important factors for successful electrical conversion of atrial fibrillations are 1) a biphasic impulse, 2) low transthoracic impedance and 3) a short history of atrial fibrillation.