Contribution of endogenous bradykinin to fibrinolysis, inflammation, and blood product transfusion following cardiac surgery: a randomized clinical trial.

Bradykinin increases during cardiopulmonary bypass (CPB) and stimulates the release of nitric oxide, inflammatory cytokines, and tissue-type plasminogen activator (t-PA), acting through its B2 receptor. This study tested the hypothesis that endogenous bradykinin contributes to the fibrinolytic and inflammatory response to CPB and that bradykinin B2 receptor antagonism reduces fibrinolysis, inflammation, and subsequent transfusion requirements. Patients (N = 115) were prospectively randomized to placebo, ε-aminocaproic acid (EACA), or HOE 140, a bradykinin B2 receptor antagonist. Bradykinin B2 receptor antagonism decreased intraoperative fibrinolytic capacity as much as EACA, but only EACA decreased D-dimer formation and tended to decrease postoperative bleeding. Although EACA and HOE 140 decreased fibrinolysis and EACA attenuated blood loss, these treatments did not reduce the proportion of patients transfused. These data suggest that endogenous bradykinin contributes to t-PA generation in patients undergoing CPB, but that additional effects on plasmin generation contribute to decreased D-dimer concentrations during EACA treatment.

Comparative effects of angiotensin receptor blockade and ACE inhibition on the fibrinolytic and inflammatory responses to cardiopulmonary bypass.

The effects of angiotensin-converting enzyme (ACE) inhibition and angiotensin II type 1 receptor blockade (ARB) on fibrinolysis and inflammation after cardiopulmonary bypass (CPB) are uncertain. This study tested the hypothesis that ACE inhibition enhances fibrinolysis and inflammation to a greater extent than ARB in patients undergoing CPB. One week to 5 days before surgery, patients were randomized to ramipril 5 mg/day, candesartan 16 mg/day, or placebo. ACE inhibition increased intraoperative bradykinin and tissue-type plasminogen activator (t-PA ) concentrations as compared to AR B. Both ACE inhibition and AR B decreased the need for plasma transfusion relative to placebo, but only ACE inhibition decreased the duration of hospital stay. Neither ACE inhibition nor AR B significantly affected concentrations of plasminogen activator inhibitor-1 (PAI -1), interleukin (IL )-6, IL -8, or IL -10. ACE inhibition enhanced intraoperative fibrinolysis without increasing the likelihood of red-cell transfusion. By contrast, neither ACE inhibition nor ARB affected the inflammatory response. ACE inhibitors and ARBs may be safely continued until the day of surgery.

Clinical trial: a randomized controlled study on prevention of variceal rebleeding comparing nadolol + ligation vs. hepatic venous pressure gradient-guided pharmacological therapy.

BACKGROUND: Hepatic venous pressure gradient (HVPG) monitoring of therapy to prevent variceal rebleeding provides strong prognostic information. Treatment of nonresponders to beta-blockers +/- nitrates has not been clarified. AIM: To assess the value of HVPG-guided therapy using nadolol + prazosin in nonresponders to nadolol + isosorbide-5-mononitrate (ISMN) compared with a control group treated with nadolol + ligation. METHODS: Cirrhotic patients with variceal bleeding were randomized to HVPG-guided therapy (n = 30) or nadolol + ligation (n = 29). A Baseline haemodynamic study was performed and repeated within 1 month. In the guided-therapy group, nonresponders to nadolol + ISMN received nadolol and carefully titrated prazosin and had a third haemodynamic study. RESULTS: Nadolol + prazosin decreased HVPG in nonresponders to nadolol + ISMN (P < 0.001). Finally, 74% of patients were responders in the guided-therapy group vs. 32% in the nadolol + ligation group (P < 0.01). The probability of rebleeding was lower in responders than in nonresponders in the guided therapy group (P < 0.01), but not in the nadolol + ligation group (P = 0.41). In all, 57% of nonresponders rebled in the guided-therapy group and 20% in the nadolol + ligation group (P = 0.05). The incidence of complications was similar. CONCLUSIONS: In patients treated to prevent variceal rebleeding, the association of nadolol and prazosin effectively rescued nonresponders to nadolol and ISMN, improving the haemodynamic response observed in controls receiving nadolol and endoscopic variceal ligation. Our results also suggest that ligation may rescue nonresponders.

Successful coronary artery bypass surgery in a patient with AIDS.

We report the case of a 47-year-old man with AIDS who underwent a successful quadruple coronary artery bypass operation. The improving prognosis of patients with HIV/AIDS, in addition to the reported incidence of plasma lipid abnormalities in patients receiving protease inhibitors, are laying the groundwork for a larger population in which premature coronary artery disease develops. Operative risk, immunosuppressive effect of cardiopulmonary bypass, and practical considerations in the care of these patients are discussed.

Axilloaxillary cardiopulmonary bypass: a practical alternative to femorofemoral bypass.

BACKGROUND: Peripheral arterial and venous cannulation for cardiopulmonary bypass is used increasingly for patients undergoing minimally invasive cardiac operations, complex reoperations, or repair of aortic dissection or aneurysm, and for patients with extensive arteriosclerotic aortic disease in whom aortic cannulation is a prohibitive embolic risk. The common femoral artery and vein are most commonly used for peripheral cannulation, but these sites may be predisposed to complications, primarily because the femoral vessels are commonly involved with arteriosclerotic disease. We have recently begun to use the axillary artery and axillary vein as alternative cannulation sites, achieving full cardiopulmonary bypass, providing antegrade aortic flow, and avoiding many of the complications associated with other sites. METHODS: Seven patients with peripheral vascular or aortic disease, or both, prohibiting safe aortic or femoral cannulation underwent cardiopulmonary bypass through axillary artery and axillary vein cannulation, approached through a small single subclavicular incision. RESULTS: All patients were successfully cannulated and axilloaxillary cardiopulmonary bypass was possible without the need for additional cannulas. All axillary vessels were closed primarily without complication. CONCLUSION: For an expanding population of patients with peripheral vascular and aortic disease, axilloaxillary bypass is a safe and practical alternative to aortic or femoral cannulation.

Orthotopic pulmonic valve replacement with a pulmonary homograft as an interposition graft.

Pulmonary regurgitation (PR) following nonvalved reconstruction of the right ventricular outflow tract is usually well tolerated. However, a small percentage of patients develop progressive right ventricular dilatation and failure due to long-standing PR. When this group of patients becomes refractory to medical management, pulmonic valve replacement (PVR) may offer symptomatic relief and hemodynamic improvement. From a cumulative experience, the pulmonary homograft may be the optimal choice for PVR due to its very low transvalvular gradient assuring optimal hemodynamics, the absence of anticoagulation-related and thromboembolic complications, and the excellent mid-term results when compared to other valved conduit, including the aortic homograft. We report our experience in two patients who have been operated upon at the BWH between March and August 1995 for severe pulmonary valve insufficiency and right heart failure, who received cryopreserved pulmonary homografts. We also describe our technique of PVR using a pulmonary homograft as an orthotopic root replacement.

Coronary artery bypass grafting in an achondroplastic dwarf.

To our knowledge, coronary bypass for complications of coronary artery disease in achondroplasia has not previously been described. Achondroplasia, in and of itself, is not a contraindication to coronary bypass. Although the anatomic reserve of saphenous vein is less in achondroplastic dwarfs than in people of normal stature, that vessel and the internal mammary artery can be harvested in routine fashion. A 60-year-old woman with several risk factors for coronary artery disease underwent successful bypass surgery, which included the use of both a saphenous vein and the left internal mammary artery.

Postoperative intramyocardial abscess caused by mucormycosis.

We report the case of an intramyocardial abscess caused by mucormycosis that arose after cardiac operation. Several causes of immunosuppression in a 71-year-old woman were exacerbated after she underwent coronary revascularization. Before she died of multiple organ system dysfunction, a variety of supraventricular and ventricular arrhythmias, as well as complete heart block, developed, but the cause was not clear until autopsy revealed a large septal myocardial abscess due to mucormycosis.