The radial artery as a conduit for coronary artery bypass grafting: review of current knowledge.

The effect of coronary artery bypass grafting (CABG) lasts as long as the grafts are patent. The internal mammary artery has been considered the "golden" graft due to the superb long-term patency, exceeding 90% at 10 years. The saphenous vein grafts, unfortunately, tend to occlude with a rate of 10-15% within a year after surgery, and eventually, at 10 years after the operation, as much as 60-70% of these vein grafts are either occluded or have angiographic evidence of atherosclerosis. The search for another "arterial conduit", the radial artery, has intensified through the last 15 years in hope to provide a better graft than the saphenous vein for CABG. This article reviews the current knowledge for the radial artery as a conduit in CABG.

Prospective randomized evaluation of stentless vs. stented aortic biologic prosthetic valves in the elderly at five years.

OBJECTIVES: Randomized trials comparing stentless to stented bioprostheses for aortic valve replacement in elderly are scarce. The aim of this study was early and mid-term evaluation of these bioprostheses, with regards to clinical outcome and hemodynamic performance. METHODS: Between September 1999 and January 2001, 40 patients with aortic stenosis, over the age of 75 years, were randomly assigned to receive either the stented Perimount (n=20) or the stentless Prima Plus (n=20) bioprosthesis. Clinical outcomes, left ventricular mass regression, effective orifice area, ejection fraction and mean gradients were evaluated at discharge, six months, one year and five years after surgery. RESULTS: At five years, there were 5/20 (25%) deaths in the stentless group and 6/20 (30%) deaths in the stented group (all non-valve-related). There was one case of endocarditis in each group, early postoperatively. Overall, a significant decrease in left ventricular mass was found five years postoperatively. However, there was no significant difference in the rate and completeness of LV-mass regression between the groups (LV mass index 114+/-34.1 vs. 120+/-27.2). Furthermore, hemodynamic performance of the valves (mean gradient of 9.9+/-4.8 mmHg vs. 10.2+/-4.2 mmHg) did not differ significantly between the groups. CONCLUSIONS: At five years, stentless valves were not superior to the stented valves, with regards to hemodynamic performance, regression of left ventricular mass and clinical outcome.

Two hundred forty minimally invasive mitral operations through right minithoracotomy.

BACKGROUND: This study reports of our 7-year experience with minimally invasive mitral valve operations using the transthoracic clamp technique, reviewing morbidity and mortality as well as echocardiographic follow-up results. METHODS: Between 1997 and 2004, 241 patients (121 male; aged 56 +/- 14 years) underwent minimally invasive mitral valve surgery through right thoracotomy using the transthoracic clamp technique. Reconstructions were done in 199 patients, and 42 valves were replaced. Mean length of incision was 7.0 +/- 1.2 cm. Mean preoperative New York Heart Association functional class was 2.6 +/- 0.9. RESULTS: Thirty-day mortality was 3.3% (n = 8). Operating, bypass, and cross-clamp times averaged 241 +/- 52, 142 +/- 40, and 84 +/- 26 minutes, respectively. Seven patients (2.9%) had conversion to sternotomy. Nine patients (3.7%) underwent reexploration for bleeding. Mean intensive care unit and hospital stay were 18 hours and 8.1 days, respectively. Mean follow-up was 30 +/- 18 months (range, 3 to 76). Echocardiographic follow-up documented persistently competent valve function in all but 6 patients who had grade III regurgitation. Five of them underwent mitral valve re-reconstruction and 1 underwent transplantation. At 76 months, freedom from nontrivial recurrent mitral regurgitation and reoperation were 92.3% and 96.2%, respectively. Actuarial survival at 76 months, including early mortality, was 90.7%. Thoracic wounds were free from infection in all patients. CONCLUSIONS: This study demonstrates that the direct vision, transthoracic clamp technique for minimally invasive mitral valve surgery is reproducible with low mortality and morbidity rates. It results in excellent cosmesis and abolished the risk of thoracic wound infection. Results are comparable to midterm outcomes of conventional operations.

Echocardiographic assessment in minimally invasive mitral valve surgery.

BACKGROUND: Due to limited exposure, removal of intracavitary air and visual assessment of cardiac function during minimally invasive procedures are not always possible. We analysed the utility of intraoperative transesophageal echocardiography (TEE) and postoperative transthoracic echocardiographic (TTE) in minimally invasive mitral valve (MV) procedures. MATERIAL/METHODS: We evaluated data from 163 consecutive patients undergoing isolated minimally invasive MV replacement (n=40) or repair (n=123) via small right anterolateral thoracotomy (121 complex mitral procedures). Cardioplegic arrest was achieved using either endoaortic (n=23) or transthoracic aortic clamp (n=140). In addition to preoperative TTE, TEE was used intraoperatively before and after cardiopulmonary bypass (CPB). Postoperative TTE was performed to monitor valve function at 3 and 12 months, and at 5-year follow-up. RESULTS: Pre-CPB TEE was useful to assess valve dysfunction and assist in placement of the arterial and venous cannulas. During CPB, placement and positioning of the endoclamp were guided effectively in all but 4 patients, in whom recurrent balloon migration necessitated secondary transthoracic aortic clamping. TEE detected one acute retrograde aortic dissection and one circumflex artery occlusion. After 18.7+/-10.6 months follow-up, all patients except three improved symptomatically and had consistently good valve function. CONCLUSIONS: Intraoperative TEE is essential for minimally invasive MV surgery, because it allows immediate control of valve function before and after surgery. It is useful to detect unexpected complications requiring immediate remedy. Postoperative echocardiographic results show that minimally invasive MV surgery is a good alternative to conventional surgery even in complex MV repairs.

Minimally invasive port access versus conventional mitral valve surgery: prospective randomized study.

BACKGROUND: We compared the port access mitral valve surgery with the conventional procedure through median sternotomy in a prospective randomized study. METHODS: Forty elective patients with mitral valve disease were prospectively randomized to undergo minimally invasive (group I) or conventional (group II) mitral valve operation. The patients of group I had limited access through right small anterior thoracotomy and a femorofemoral cardiopulmonary bypass system using the endoclamp technique. To assess the efficiency and safety of the procedure, intraoperative and postoperative clinical data and markers of myocardial, cerebral, and lower limb ischemia were collected. Pulmonary function tests were performed to compare the preservation of pulmonary function. Neuropsychological tests were conducted for quantification of neurological and cognitive disorders. RESULTS: Mitral valve reconstructions were performed in 28 patients (70%) in both groups. Intraoperative procedure-associated problems were experienced in 9 patients (45%) in group I, and 6 of them (30%) had to be converted to direct transthoracic aortic clamping. Markers of myocardial and cerebral damage as well as pulmonary and neuropsychological tests did not show statistically significant difference between groups. CONCLUSIONS: The minimally invasive port access technique for mitral valve surgery can be done with similar clinical safety as procedures through median sternotomy. The problems with endoclamping have forced us to change our practice to the more simple and economic transthoracic aortic clamping technique.

Initial experience with a minimized extracorporeal bypass system: is there a clinical benefit?

BACKGROUND: Drawbacks of conventional cardiopulmonary bypass (CPB) are increased inflammatory response, deteriorated coagulation and systemic organ dysfunction. A closed extracorporeal circuit (CorX) features reduced foreign surface area and priming volume. Potential benefits were studied in comparing the CorX system with conventional CPB in arrested heart coronary artery bypass grafting (CABG). METHODS: Two hundred and four patients were randomly assigned either to CorX system (n = 101, group A) or a standard CPB with cardiotomy reservoir (n = 103, group B). Besides evaluation of perioperative data and routine blood samples, we focused on lung function and perioperative bleeding. Polymorphonuclear elastase (PMNE) and terminal complement complex (TCC) served to assess inflammatory response. RESULTS: Patient demographics and operative data did not differ between groups. Postoperative lung function was not significantly impaired comparing groups A and B. Intraoperative blood loss was significantly higher in group A compared with group B (1245 +/- 947 mL vs 313 +/- 282 mL, p < 0.0001) as well as the need of fresh frozen plasma. Postoperative chest drainage did not differ significantly between groups. Two patients in each group required re-exploration due to bleeding. One hour after CPB, PMNE as well as TCC were significantly lower in group A compared with group B (PMNE: 76 +/- 44 ng/mL vs 438 +/- 230 ng/mL, p < 0.0001; TCC: 16 +/- 8 IU/mL vs 29 +/- 19 IU/mL, p < 0.0001). CONCLUSIONS: The CorX system is safe and feasible in patients undergoing CABG. Despite of markedly reduced inflammatory reaction, no clinical benefit was observed.