Speziali, Giovanni

Objective Functional tricuspid regurgitation (TR) is recognized as a significant cause of morbidity and mortality in cardiothoracic surgery. We hypothesized that a variably expandable, transvalvular balloon mounted on a catheter could be percutaneously inserted and fixed to the right ventricle apex. This novel approach could provide a minimally invasive way to eliminate clinically relevant TR caused by annular dilatation. This study was performed to test the ex vivo hemodynamic effects and the feasibility of the “balloon plug concept.” Methods Twenty harvested calf tricuspid valves were placed in a mechanical simulator. Tricuspid regurgitation was created by annular stretching and displacement of the papillary muscles so as to create central TR. A flexible catheter with a 4-cm–long, soft, fusiform balloon was positioned across the valve so that the balloon was suspended centrally across the valve annular plane. After activating the mechanical ventricle, data were collected with balloon inflation volumes of saline from 5 to 20 mL. Transvalvular pressure gradients and leaflet mechanics were evaluated with incremental inflation. Results In all cases, 5-mL inflation did not significantly reduce TR and 20-mL inflation caused obstruction to antegrade flow (mean transvalvular gradient > 4 mm Hg). Inflation between 10 and 15 mL caused significant reduction in TR with acceptable transvalvular gradients (<3 mm Hg). Conclusions The balloon plug concept showed promising ex vivo hemodynamic results. In vivo investigations are warranted to evaluate percutaneous techniques, thrombogenicity, and effects of repeated balloon-leaflet contact on valve integrity.

Background Recently, various studies have questioned the efficacy of intraoperative acute normovolemic hemodilution (ANH) in reducing bleeding and the need for allogeneic transfusions in cardiac surgery. The aim of the present study was to reevaluate the effects of a low-volume ANH in elective, adult open-heart surgery. Methods Two hundred four consecutive adult patients undergoing cardiac surgery were prospectively randomized in a nonblinded manner into two groups: ANH group (103 patients), where 5-8 ml/kg of blood was withdrawn before systemic heparinization and replaced with colloid solutions, and a control group, where no hemodilution was performed (101 patients). Procedures included single and multiple valve surgery, aortic root surgery, coronary surgery combined with valve surgery, or partial left ventriculectomy. The purpose of the study was to evaluate the efficacy of ANH in reducing the need for allogeneic blood components. Routine hematochemical evaluations, perioperative blood loss, major complications, and outcomes were also recorded. Results No differences were found between the groups regarding demographics, baseline hematochemical data, and operative characteristics. There was no difference in the amount of transfusions of packed red cells, fresh frozen plasma, platelet concentrates, total number of patients transfused (control group, 36% vs. ANH group, 34.3%; P = 0.88), and amount of postoperative bleeding (control group, 412 ml [313-552 ml] vs. ANH group, 374 ml [255-704 ml]) (median [25th-75th percentiles]); P = 0.94. Further, perioperative complications, postoperative hematochemical data, and outcomes were not different. Conclusions In patients undergoing elective open-heart surgery, low-volume ANH showed lack of efficacy in reducing the need for allogeneic transfusions and postoperative bleeding.