Hemolysis at different vacuum levels during vacuum-assisted venous drainage: a prospective randomized clinical trial.

BACKGROUND: There are several reports on the application of variable degrees of vacuum pressure to hardshell venous reservoirs. The aim of the current study was to compare the hemolytic effects of vacuum-assisted venous drainage (VAVD) at two different vacuum levels with the classical gravity siphon method. METHODS: A prospective, equally randomized (1: 1: 1), parallel group study was performed in elective coronary artery bypass grafting (CABG) operations. PATIENTS: (n = 162) were divided into three groups: gravity siphon (group 1, n = 55), VAVD at -40 mmHg (group 2, n = 55) and VAVD at -80 mmHg (group 3, n = 52). Hemolysis tests were performed at 2, 24 and 48 h following the operations. RESULTS: There were no deaths in this study. Plasma-free hemoglobin (PfHb) levels showed a difference at 2 h (p < 0.001) compared to 24 h (p = 0.02) between the groups. Haptoglobin (Hp) levels also revealed hemolysis in groups 2 and 3 at all sampling times. CONCLUSIONS: Constant negative suction at -80 mmHg during elective coronary bypass operations caused more hemolysis. We do not recommend a constant suction of -80 mmHg for VAVD.

Different CABG methods in patients with chronic obstructive pulmonary disease.

BACKGROUND: Pulmonary dysfunction is still a major problem in coronary artery bypass grafting (CABG). The purpose of this randomized study was to determine the effect of different CABG techniques on pulmonary function. METHODS: Fifty eight patients with severe obstructive pulmonary disease had elective isolated coronary surgery. The surgical methods for the patients with chronic obstructive pulmonary disease (COPD) were standard CABG in 18 patients (group 1), beating heart surgery in 19 patients (group 2), and minimally invasive direct coronary artery bypass grafting (MIDCABG) in 21 patients (group 3). RESULTS: The earliest extubation time was from group 3 (p < 0.001). The average stay in the intensive care unit was significantly longer in group 1 (2.6 +/- 1.5 days) than in groups 2 (1.4 +/- 0.8 days) and 3 (1.1 +/- 0.8 days) (p < 0.05). The most prevalent respiratory morbidity was atelectasis that developed in 6 patients from group 1, in 2 patients from group 2, and in 3 patients from group 3. Forced expiratory volumes in 1 second (FEV1) obtained in the second postoperative month were significantly lower than preoperative values only in group 1 (p < 0.05). Forced vital capacity (FVC) values were significantly lower than the preoperative values in all three groups (p < 0.05). CONCLUSIONS: Off-pump bypass surgical procedures are more advantageous than on-pump methods for patients with COPD. These patients can be operated on using the beating heart technique or by using MIDCABG to prevent side effects of CPB on pulmonary function and effects of sternotomy.

Midterm angiographic assessment of coronary artery bypass grafting without cardiopulmonary bypass.

BACKGROUND: Coronary bypass surgery that provides good long-term graft patency can be performed on the beating heart as a viable alternative to conventional coronary artery bypass grafting (CABG). METHODS: From September 1993 to December 1996, 696 patients underwent CABG on the beating heart at the Kosuyolu Heart and Research Hospital in Istanbul. Among them, 70 patients were chosen randomly for angiographic assessment of off-pump coronary artery bypass grafting. RESULTS: The interval from operation to angiography varied from 24 to 61 months (mean, 36.1+/-10.9 months). The patency rate of left internal mammary-left anterior descending artery anastomoses was 95.59% (patency achieved in 65 of 68 patients) and of vein grafts was 47.06% (patency achieved in 16 of 34 patients) (p < 0.0001). The patency rates of grafts anastomosed to the left anterior descending artery were significantly higher than the rates of the grafts anastomosed to the other coronary arteries (95.71% versus 45.45%, p < 0.0001). Multivariate analysis showed that graft type (p < 0.0001) and hyperlipidemia (p = 0.023) were significant predictors for graft occlusion. Left ventricular function improved significantly after CABG (p = 0.04). Reintervention (using percutaneous transluminal cardiac angioplasty) and reoperation rates were 0.97% and 1.4%, respectively. CONCLUSIONS: Off-pump coronary artery bypass grafting appears to produce midterm and long-term patency rates that are comparable to those of conventional techniques; that is especially true in cases of arterial conduits and of conduits anastomosed to the left anterior descending artery.

Paravalvular leakage after mitral valve replacement: is left atrial enlargement an additional indication for reoperation?

BACKGROUND AND AIM OF THE STUDY: Prostheses used to treat heart valve disease improve patient survival, but have certain disadvantages. Paravalvular leakage (PVL) is a rare complication after mitral valve replacement (MVR), and can impair cardiac function and reduce the patient's functional capacity, depending on the degree of periprosthetic regurgitation. METHODS: Between 1985 and July 1999, 2,502 patients underwent MVR with or without concomitant cardiac procedures. Of these patients, 33 (18 males, 15 females; mean age 39.8+/-15.3 years; range: 12-62 years) had PVL of differing degree. The interval between MVR and observation of PVL was 30.5+/-31.5 months (range: 1-126 months), and the period after diagnosis was 22.6+/-31.5 months (range: 2-114 months). Fourteen patients (42.4%) underwent reoperation (RO group), and 19 (57.6%) were followed medically (ME group). Indications for reoperation were reduction of functional capacity, echocardiographically proven serious mitral regurgitation, and hemolysis. RESULTS: Reoperative mortality was 3.0% (1/33), and late mortality 3.1% (1/32) for all patients. Cumulative survival after PVL was 90.2+/-6.7% at both five and ten years. Annular calcification (33.0%) and infective endocarditis (18.2%) were important predictive factors for development of PVL. Only one patient required second re-do surgery. Univariate and forward stepwise logistic regression analyses showed that there was no predictor for the development of severe PVL requiring a second reoperation. No difference was observed between left ventricular dimensions before and after periprosthetic regurgitation. The only significant finding between groups was an increase in left atrial diameter in RO patients after the development of PVL (p <0.05). CONCLUSION: Among patients undergoing MVR there are no clinical features to distinguish who will develop severe PVL during follow up. If PVL reduces the patient's functional capacity or causes serious hemolysis, or if severe PVL is evaluated echocardiographically, then reoperation must be performed. Mild or moderate mitral regurgitation without impairment of functional capacity may be followed medically. In asymptomatic patients, enlargement (>5%) of the left atrial diameter following development of moderate PVL may be a valuable criterion for deciding when to reoperate.

Mechanical versus biological valve prosthesis in the mitral position: a 10-year follow up of St. Jude Medical and Biocor valves.

BACKGROUND AND AIM OF THE STUDY: During the past 30 years, the development of mechanical and biological valves has led to major improvements in patient survival. Here, we present long-term results obtained with both types of prosthesis. METHODS: At our institution, between 1985 and 1989, 158 patients received a Biocor porcine bioprosthesis, and 100 patients a St. Jude Medical (SJM) mechanical valve. Preoperatively, mean age, male:female ratio, NYHA functional class and pathology of mitral valve disease were similar in both groups. RESULTS: The 30-day mortality was 4.4% in the Biocor group and 4% in the SJM group, the major cause being congestive heart failure. Late mortality was 17.9% and 15.6% respectively in the two groups, but valve-related mortality was very low in both (1.3% versus 4.2%). Ten-year survival was similar in each group (77.8+/-3.4% versus 81.0+/-3.9%; p = 0.538). Ten-year freedom from anticoagulant-related hemorrhage was higher with Biocor prostheses (99.3+/-0.7% versus 90.9+/-3.1%; p = 0.007). Valve thrombosis was seen only in the SJM group, and structural valve degeneration (SVD) only in the Biocor group. Ten-year freedom from reoperation was lower in the Biocor group (84.9+/-3.2% versus 92.2+/-2.8%; p = 0.206). The significant causes of reoperation were SVD in the Biocor group and valve thrombosis in the SJM group. Freedom from prosthetic valve endocarditis was similar in both groups (96.3+/-1.6% versus 95.5+/-2.2%). CONCLUSION: As no difference was seen in survival and reoperation rates between patients receiving either bioprostheses or mechanical valves, the valve used will depend on the surgeon's choice and the type of patient, notably elderly patients who are intolerant of anticoagulation, and young women wishing to have children.