Should the aortic valve be replaced in patients with mild aortic stenosis admitted for coronary surgery?

BACKGROUND: The question whether the aortic valve in patients with mild aortic stenosis undergoing coronary artery bypass grafting (CABG) should be replaced or left alone is still controversial. METHODS: Between 01/1995 and 03/2004, 38 patients (30 male, 8 female, mean age 70.9 +/- 7.8 years) required redo AVR 7.1 +/- 4.8 years after primary CABG, while 202 patients (125 male, 77 female, mean age 72.7 +/- 7.8 years) underwent combined AVR and CABG (1.9 +/- 0.8 grafts/patient). To evaluate the different approaches, the data of the redo-AVR group were compared with the data of a propensity-score matched group of AVR + CABG patients. RESULTS: All patients survived the procedure; the 30-day survival was 94.7 % in both groups. The 1- and 5-year survival rates were 94.7 % and 83.8 % in the AVR after CABG group, and 94.7 % and 86.9 % in the AVR + CABG group, respectively. The late mortality was 28.9 % in the AVR after CABG and 25 % in the AVR + CABG group. Statistically, significant differences regarding perioperative mortality and morbidity could not be detected, neither with nor without propensity score analysis. CONCLUSION: Combined AVR and CABG in patients with coronary artery disease and mild to moderate aortic stenosis seems advisable in an institution with an equally low perioperative risk for both procedures, because the patient will need only one surgical procedure instead of undergoing surgery with all the associated risks twice.

X-ray focusing with compound lenses made from beryllium.

We have measured the intensity profile and transmission of x rays focused by a series of biconcave spherical unit lenses fabricated from beryllium. The use of beryllium extends the range of operation of compound refractive lenses, improving transmission, aperture size, and gain. The compound refractive lens was composed of 160 biconcave unit lenses, each with a radius of curvature of 1.9 mm. Two-dimensional focusing with a gain of 1.5 was obtained at 6.5 keV with a focal length of 93 cm. The effective aperture of the compound refractive lens was measured as 600 mum , with 9% peak transmission.

Tetralogy of Fallot: influence of surgical technique on survival and reoperation rate.

BACKGROUND: The influence of different surgical techniques in patients with Tetralogy of Fallot (TOF) on long-term survival and reoperation rate is still a matter of controversy. PATIENTS AND METHODS: The data of 266 patients (152 male, 114 female, mean body weight: 13.4 +/- 11.9 kg, mean age 4.1 +/- 6.0 years) with TOF, including 30 patients (11.2 %) with TOF/pulmonary atresia, were analyzed retrospectively. A palliative surgical procedure preceded definite correction between 1975 and 1999 in 46 patients (17.5 %). The surgical technique consisted of a transannular patch in 103 patients (40.1 %); in 133 patients (51.8 %), a non-transvalvular technique was used. In 33 patients (12.3 %), a conduit was implanted into the right ventricular outflow tract (RVOT). For surgical access to the cardiac defects, a transventricular approach was used in 138 patients, and a transatrial/trans-pulmonary approach in 26 patients. The mean follow-up time of all patients was 6.6 years. RESULTS: Kaplan-Meier survival for the entire group was 86.2 % at one year and remained stable at 85.6 % after 5 years. The 30-day mortality was 10.1 % (27 patients). Fatal risk factors were: previous cardiac surgery, preoperative oxygen saturation (SO(2)) < 80 %, diagnosis of pulmonary atresia, prolonged aortic clamping or bypass time, postoperative infections, and early revisions. Freedom from reoperation was 91.6 % after 5, 84.5 % after 10, and 52.6 % after 20 years. There was no correlation between the different surgical techniques (transannular patch, non-transvalvular techniques, transventricular approach) applied and the mortality or the rate of reoperations. CONCLUSIONS: In our series of TOF patients operated over a period of 25 years, we were unable to assess an influence of the surgical technique used for definite correction on mortality or reoperation rate. Pulmonary atresia in patients with TOF is associated with a higher risk of death and reoperation.

Minimally invasive coronary artery revascularization on the beating heart.

BACKGROUND: The quality of surgical beating heart revascularization is frequently questioned, especially when the surgical access is limited. Nevertheless, the number of off-pump coronary procedures is expanding worldwide. METHODS: Since getting started with minimally invasive direct coronary artery bypass to anterior myocardial vessels in June 1996, 306 patients received left internal mammary artery grafting through an anterior minithoracotomy. Risk increasing comorbidities were present in 168 of them. Particular attention was paid to early postoperative angiographic results and complications. RESULTS: The 30-day mortality summed up at 1.0% and was limited to patients with additional risks for conventional bypass grafting. Early postoperative control angiographies in 232 patients confirmed a global patency rate of 97.8%, revealing in addition four unexpected malinsertions to diagonal branches. In surviving patients major complications like myocardial infarction, stroke, or multiorgan failure were completely absent. CONCLUSIONS: Minimally invasive direct coronary artery bypass grafting appears to allow for a safe and effective revascularization of the left anterior descending artery by use of the left internal mammary artery. Especially patients with risk increasing comorbidities should benefit from this approach, provided the surgical indication based on a dominating left anterior descending artery lesion. Angiographic minimally invasive direct coronary artery bypass results seem to fulfill the expectations generated by results obtained in conventional left internal mammary artery grafting and appear to be superior to interventional means.

Transthoracic fistula with erosion of the ascending aorta along an IMA-protecting graft.

Internal mammary artery (IMA) graft protection with nonbiodegradable material, such as polytetrafluorethylene (PTFE), is recognized as an effective means for preventing overexuberant adhesion development as well as injury of retrosternally crossing arterial grafts in the event of resternotomy and should enable better identification of the IMA graft. It is still uncertain whether the use of PTFE material is suitable for diabetic patients with complete arterial revascularization due to potential infectious complications. We report on a young diabetic patient after arterial T-grafting due to severe coronary disease and readmission with wound infection and retrosternal fistula formation 8 months after operation.

Human cytokine responses to coronary artery bypass grafting with and without cardiopulmonary bypass.

BACKGROUND: Coronary artery bypass grafting (CABG) is associated with a systemic inflammatory response. This has been attributed to cytokine release caused by extracorporeal circulation and myocardial ischemia. This study compares the inflammatory response after CABG with cardiopulmonary bypass and after minimally invasive direct coronary artery bypass grafting (MIDCABG) without cardiopulmonary bypass. METHODS: Cytokine release and complement activation (interleukin-6 and interleukin-8, soluble tumor necrosis factor receptors 1 and 2, complement factor C3a, and C1 esterase inhibitor) were determined in 24 patients before and after CABG or MIDCABG. The maximum body temperature, chest drainage, and fluid balance were recorded for 24 hours after operation. RESULTS: Release of interleukin-6, interleukin-8, and tumor necrosis factor receptors 1 and 2 was significantly higher (p < or = 0.005) in the CABG group than the MIDCABG group just after operation. After 24 hours, a significant increase in interleukin-6 was also found in the MIDCABG group (p = 0.001) compared with preoperative value. Body temperature and fluid balance were significantly higher after CABG (p < or = 0.001). CONCLUSIONS: Minimally invasive direct coronary artery bypass grafting represents a less traumatizing technique of surgical revascularization. The reduction in the inflammatory response may be advantageous for patients with a high degree of comorbidity.

Coronary revascularization without cardiopulmonary bypass in patients with pectus excavatum.

BACKGROUND: Coronary revascularization in patients with pectus excavatum is technically difficult through a median sternotomy secondary to the posterior displacement of the sternum and the asymmetric angulation that it produces. The role of minimally invasive coronary artery bypass grafting (MIDCABG) in this subset of patients was evaluated. METHODS: In 1998, four patients with pectus excavatum underwent revascularization of the left anterior descending artery without cardiopulmonary bypass through a left anterior minithoracotomy. RESULTS: All patients underwent the procedure without intraoperative complications and postoperative angiography demonstrated adequate graft patency. CONCLUSIONS: The advantages of MIDCABG in patients with pectus excavatum is the superior exposure to the LAD and LIMA and avoidance of a median sternotomy and cardiopulmonary bypass. This procedure is deemed safe and effective in patients with such deformities of the chest wall.

Different approaches for minimally invasive closure of atrial septal defects.

BACKGROUND: To improve the acceptance of cosmetic results after closure of atrial septal defects, anterior or lateral thoracotomies are preferred rather than median sternotomies. Along with the availability of minimally invasive techniques, a further reduction in incision length appeared feasible while preserving thoracic stability. METHODS: Various minimally invasive approaches differing in the type of incision and mode of cannulation have been applied under conditions of normothermic ventricular fibrillation. In technique 1 (n = 5), a right parasternal mini-incision was combined with a central aortic and bicaval cannulation. Technique 2 (n = 2) was composed of an anterior submammary mini-incision with femoral arterial and central bicaval cannulation. To optimize the surgical access, the transincisional cannulation of the superior vena cava was replaced by a percutaneous cervical cannulation (technique 3, n = 17). RESULTS: Effective atrial septal defect closure assessed by intraoperative echocardiography was achieved in all patients. Central neurologic complications were completely absent. Besides temporary atrial fibrillation in one case, no other cardiac complications occurred. There were no cases with complicated wound healing. CONCLUSIONS: Along with modified cannulation techniques and intraoperative echocardiography, minimally invasive techniques can be safely applied for atrial septal defect closure. Submammary incisions were highly accepted and allowed for adequate surgical exposure.