Isolated mitral and aortic valve replacement with the St. Jude Medical valve: a midterm follow-up.

BACKGROUND: In our country, the biological valvular prostheses predominate, considering the difficulties related to anticoagulation, even in young patients, in spite of the need for repeated operations due to the degeneration of the bioprostheses. OBJECTIVES: To report our consecutive series of recipients of isolated St Jude Medical mechanical valve prosthesis in the mitral (MVR) or aortic (AVR) position. METHODS: Data from patients operated between January 1995 and December 2003 were revised in order to determine patient survival and prosthesis-related events up to December 2006. RESULTS: One hundred sixty eight patients had MVR and 117 had AVR. In the MVR cohort, the mean age was 45 years, 75% were 55 years old or younger, and 65% were females. In the ARV cohort, the mean age was 45 years, 66% were 55 years old or younger and 69% were males. Operative mortality for AVR and MVR was 7% and 7.5%, respectively. Freedom from late mortality was 81.8% at 10 years for MVR and 83% for AVR (p=0.752). Freedom from valve-related death at 10 years for the MVR cohort and AVR was 85.6% and 88.7%, respectively (p=0.698). In the MVR cohort, the freedom from reoperation was 97% and 99% in the AVR cohort (p=0.335). Freedom from thromboembolic events was 82% in the MVR cohort and 98% in the AVR cohort (p=0.049). Freedom from bleeding was 71% in the MVR cohort and 86% n the AVR cohort (0.579). Freedom from endocarditis was 98% in the MVR cohort and 99% in the AVR cohort (p=0.534). CONCLUSIONS: This series of predominantly young adult patients undergoing isolated MVR and AVR with the St Jude Medical mechanical prosthesis confirms the good performance of this valve prosthesis in agreement with previous reports.

Blood cardioplegia with N-acetylcysteine may reduce coronary endothelial activation and myocardial oxidative stress.

OBJECTIVES: The aim of this prospective study was to compare the efficacy of intermittent antegrade blood cardioplegia with or without n-acetylcysteine (NAC) in reducing myocardial oxidative stress and coronary endothelial activation. METHODS: Twenty patients undergoing elective isolated coronary artery bypass graft surgery were randomly assigned to receive intermittent antegrade blood cardioplegia (32 degrees C-34 degrees C) with (NAC group) or without (control group) 300 mg of NAC. For these 2 groups we compared clinical outcome, hemodynamic evolution, systemic plasmatic levels of troponin I, and plasma concentrations of malondialdehyde (MDA) and soluble vascular adhesion molecule 1 (sVCAM-1) from coronary sinus blood samples. RESULTS: Patient demographic characteristics and operative and postoperative data findings in both groups were similar. There was no hospital mortality. Comparing the plasma levels of MDA 10 min after the aortic cross-clamping and of sVCAM-1 30 min after the aortic cross-clamping period with the levels obtained before the aortic clamping period, we observed increases of both markers, but the increase was significant only in the control group (P= .039 and P= .064 for MDA; P= .004 and P= .064 for sVCAM-1). In both groups there was a significant increase of the systemic serum levels of troponin I compared with the levels observed before cardiopulmonary bypass (P< .001), but the differences between the groups were not significant (P= .570). CONCLUSIONS: Our investigation showed that NAC as an additive to blood cardioplegia in patients undergoing on-pump coronary artery bypass graft surgery may reduce oxidative stress and the resultant coronary endothelial activation.

Endothelium dysfunction caused by acute pressure distension of human saphenous vein used for myocardial revascularization.

OBJECTIVE: To study morphofunctional alterations induced by brief pressure increases in human saphenous veins utilized in coronary artery bypass grafting. METHOD: Saphenous veins of 20 patients undergoing coronary artery bypass grafting, were distributed into four experimental groups, control, 100 mmHg, 200 mmHg and 300 mmHg, and submitted to pressure distention over 15 seconds using Krebs solution. The evaluation included CD34 immunohistochemistry and an In vitro vascular reactivity study in organ chambers. RESULTS: The main experimental findings were 1) From pressures of 200 mmHg there was a tendency to reduce the CD34 expression which became statistically significant at 300 mmHg; 2) There was no impairment of the contraction and relaxation as evidenced by in vitro vascular reactivity tests. CONCLUSION: Although vascular reactivity impairment was not demonstrated in vitro, the CD34 expression, measured by immunohistochemistry, shows there is endothelium dysfunction at pressures of 300 mmHg.

Efficacy and safety of aprotinin use for reoperative valvular surgery.

BACKGROUND: Preservation of the hemostatic system during cardiac surgery is a main concern, primarily after repeated cardiac operations. METHODS: We compared the outcomes of adult patients undergoing isolated reoperative valvular surgery receiving full-dose of aprotinin (redo group, n = 70) with patients experiencing primary isolated valvular surgery not receiving aprotinin (primary group, n = 135). RESULTS: The mean age was lower in the redo group (45 +/- 14 years vs 50 +/- 17 years, p = 0.036). The redo group had more female patients (73% vs 51%, p = 0.003), patients in functional class IV (15% vs 4% p = 0.009), and patients with chronic atrial fibrillation (48% vs 24%, p = 0.001). The cardiopulmonary bypass duration was longer in the redo group (119 +/- 50 minutes vs 103 +/- 41 minutes, p = 0.014). However, the blood loss was significantly lower (300 +/- 279 mL vs 776 +/- 584 mL, p = 0.001) and fewer patients needed transfusions (3.0% vs 13%, p = 0.023) in the redo group. The postoperative morbidity was similar in both groups. The postoperative in-hospital mortality was 7% in the primary group and 10% in the redo group (p = 0.419). Factors associated with postoperative in-hospital mortality were the following: age greater than 60 years (p = 0.040, odds ratio [OR] 3.0), New York Heart Association class IV (p = 0.022, OR 5.0), preoperative critical state (p < 0.001, OR 12), emergent operation (p = 0.012, OR 7.0), endocarditis (p = 0.004, OR 10.0), and reoperation due to mechanical mitral prosthesis dysfunction (p = 0.009, OR 7). CONCLUSIONS: The mortality and morbidity in redo valve surgery with aprotinin administration was comparable with primary valve surgery without aprotinin. Bleeding and transfusion requirements were significantly lower in redo patients receiving aprotinin.

Extrinsic compression of left main coronary artery from aneurysmal dilation of pulmonary trunk in a adolescent: involution after surgery occlusion of sinus venosus atrial septal defect and pulmonary trunk plasty for reduction.

We report the case of an adolescent referred with initial diagnosis of pulmonary hypertension. Non-invasive investigation disclosed a sinus venous atrial septal defect with pulmonary hypertension. The hemodynamic study confirmed diagnosis, and also showed extrinsic compression of left main coronary artery by pulmonary trunk. Surgical closure of the defect in addition to pulmonary trunk plasty were undertaken. Two years after the surgery the patient is well, with clinical signs of mild pulmonary hypertension, and showing no evidence--also on echocardiogram--of left coronary artery trunk obstruction.

Dorsal minithoracotomy for ductus arteriosus clip closure in premature neonates.

We present a new surgical technique for patent ductus arteriosus (PDA) occlusion in premature neonates (PN). Through a dorsal minithoracotomy the PDA is dissected extrapleurally with q-tips and clipped. The short surgical time, avoidance of pleural drainage, and prevention of late breast deformity are the operation highlights.