Combined Reparative Approaches for Dilated Failing Ventricles.
(J Card Surg 2005;20:S1-S2).
Journal Article↗
Biomedical subjects
Akira T Kawaguchi
Publications and source records attributed to Akira T Kawaguchi.
Novel proximal and distal anastomotic devices for coronary artery bypass surgery.
Explore the source record for details and available documents.
Anastomosis, Surgical↗
Heparin dose, transfusion rates, and intraoperative graft patency in minimally invasive direct coronary artery bypass.
BACKGROUND: Many investigators have demonstrated the short-term and midterm efficacy of minimally invasive direct coronary artery bypass (MIDCAB). However, the influence of heparin dosing during MIDCAB on postoperative and immediate graft patency is less well defined. This report outlines our experience with MIDCAB employing a variety of heparinization protocols. METHODS: The traditional MIDCAB approach was used in 152 patients who underwent single-vessel off-pump coronary artery bypass. Before the left internal mammary artery was divided, a 150-U/kg bolus of heparin sodium was given to 76 patients (group 1), and 300 U/kg was given to another 76 patients (group 2). Additional heparin was given during the procedures to maintain an activated clotting times of greater than 300 seconds for group 1 and greater than 400 seconds for group 2. RESULTS: On average, patients in group 1 required more boluses of heparin during treatment than patients in group 2. A larger standard deviation from the mean was observed for the activated clotting time in group 1 at any time during treatment than for patients in group 2. The number of revised grafts was smaller in group 2 (1/76, 1.3%) than in group 1 (4/76, 5.2%). All of these revisions revealed thrombus at the site of anastomosis. In addition, noncoronary thrombotic complications were seen in 5 patients in group 1, and none were seen in group 2. CONCLUSION: Coronary artery surgery without cardiopulmonary bypass does not trigger the systemic inflammatory response, but surgical tissue trauma remains a constant. The preserved hemostasis theoretically may lead to a procoagulant state. This study demonstrates that insufficient anticoagulation therapy can lead to intracoronary thrombosis following MIDCAB as well as increased noncoronary thrombotic complications.
Anticoagulants↗
[Partial left ventriculectomy. Past, present and future].
Although discouraging clinical results and a lack of scientific evidence decreased the initial interest in partial left ventriculectomy (PLV), factors contributing to its success and failure have now been identified by clinical observation, theoretical analyses, and data from an international registry, which are herein reviewed to outline the current status and future role of this procedure as a treatment for heart failure. Based on the same concept, new and less-invasive approaches are now being developed to reduce the diameter of the left ventricle. While PLV has been practically abandoned, these experimental approaches appear promising because they can be applied for many more patients with better cardiac condition and preserved myocardial viability, factors associated with benefits of cardiac volume reduction.
Cardiac Surgical Procedures↗
Partial left ventriculectomy--The Third International Registry Report 2002.
BACKGROUND: An international registry of partial left ventriculectomy (PLV) has been expanded, updated, and refined to include 440 cases voluntarily reported from 51 hospitals in 11 countries. RESULTS: Gender, age, ventricular dimension, etiology, ethnology, myocardial mass, operative variation or presence or absence of mitral regurgitation as well as transplant indication had no effects on event-free survival, which was defined as either absence of death or ventricular failure requiring ventricular assist device or listing for transplantation. Preoperative patient condition such as NYHA functional class IV, depressed contractility, and decompensation requiring an emergency procedure were associated with reduced event-free survival. Other risk factors included early date of surgery, lack of experience, and extended myocardial resection. Performance of PLV reached a peak by 1998 and was largely abandoned by 2000 except in Asia, where experienced institutes continue to perform PLV in patients in better condition with preserved myocardial contractility. CONCLUSION: Avoidance of delineated risk factors appears to improve recent survival and may help stratify high- or low-risk patients for PLV. An integrated approach with mechanical and biological circulatory assist may improve prognosis for patients with dilated failing hearts. While frequency of PLV has decreased, the concept of ventricular volume reduction has been extended to other volume reduction procedures and less invasive procedures now under clinical trial.
Adolescent↗
Does repair of mitral regurgitation eliminate the need for left ventricular volume reduction?
BACKGROUND: Effects of partial left ventriculectomy (PLV) remain ill-defined because mitral regurgitation (MR) repair by isolated annuloplasty alone has been reported to improve patients with dilated left ventricle and severe MR. METHODS: Among patients undergoing PLV, 120 had paired pre- and postoperative (<1 week) Doppler echocardiograms. Effects of preoperative MR were studied by comparing 45 patients with no preoperative MR (MR-) and 75 patients with significant MR (MR+; MR = 1.51 when MR is enumerated as none = 0, mild = 1, moderate = 2). RESULTS: MR- patients as compared with the MR+ group were older (53.8 vs. 49.2 years, P = 0.047), had less frequent dilated cardiomyopathy (33.3% vs 49.3%,P <0.01), similar ventricular dimension (72.3 mm vs 73.0 mm), septal thickness (9.5 mm vs 9.6 mm), posterior wall, fractional shortening (15.9% vs 16.8%) and ventricular mass (330 g vs 345 g), resulting in comparably reduced functional capacity (NYHA 3.40 vs 3.67). Although the MR- group required significantly less frequent mitral procedure (64.4% vs 84.0%, P < 0.01) and shorter cardiac arrest time, they had similar postoperative MR (0.22 vs 0.39), highly significant parallel reduction in ventricular dimension (P < 0.001 in either group), and improved %FS (P <0.001 in either group), resulting in similar hospital survival (87.1% vs 86.4%) and 90-day survival (71.1% vs 78.7%) with significantly comparable improvement in functional class (P = 0.011 in both groups). Histological severity of interstitial fibrosis (P = 0.80), weight (P = 0.93), and thickness (P = 0.76) of excised myocardium was comparable between the two groups. CONCLUSION: Patients with no preoperative MR were found to benefit from PLV as did patients with significant MR. Beneficial effects of PLV appeared to derive mainly from volume reduction rather than abolished MR in this study.
Adolescent↗
Ventricular volume reduction procedures.
Although partial left ventriculectomy (PLV) has been abandoned in many institutions, a few hospitals continue to perform it with a relatively favorable outcome. Other volume reduction procedures have become popular with renewed interest in ventricular reshaping to improve function. Although recent refined selection criteria have improved survival with PLV, earlier unpredictable results prompted less invasive procedures based on the same physiologic concept of reducing radius or wall tension by wrapping, piercing, or clasping. These new techniques are not only less invasive but also reversible and adjustable and appear safer for less symptomatic patients at risk of progressive heart failure. Nonetheless, mechanisms of action and degrees of volume reduction and/or restriction need to be delineated before widespread clinical application.
Cardiac Surgical Procedures↗
Factors affecting ventricular function and survival after partial left ventriculectomy.
BACKGROUND: Partial left ventriculectomy (PLV) helps some patients but is deleterious in others. Selection of patients who will benefit from PLV, and exclusion of those who will not is necessary for safe and effective application of the procedure. METHODS: Sixty-nine consecutive patients who underwent PLV were monitored with pressure-volume relationship analyses, Doppler echocardiography, and histopathologic studies of excised myocardium. These parameters were correlated with postoperative stroke volume (SV, ml), cardiac output (CO, L/min), ventricular function (improved, no change, or deteriorated), and postoperative course (duration of survival and/or hospital discharge). RESULTS: Positive responders (n = 36) with increased SV at reduced end diastolic pressure had significantly larger preoperative end-systolic dimension, smaller SV, and less stroke work with milder fibrosis than non- or negative responders (n = 33). In multivariate analyses, poor preoperative hemodynamics were associated with increased SV and CO, but these improvements did not lead to improved survival. Postoperative survival was negatively affected by larger preoperative left ventricular end-diastolic volume and larger excised-muscle-weight. Milder fibrosis and thicker excised wall were consistently related to improved ventricular function and survival. CONCLUSION: Although effects of PLV are related to preoperative status, factors affecting postoperative ventricular function and survival were often discordant. While poor preoperative ventricular function was associated with functional improvement without survival benefit, milder fibrosis, thicker excised wall and less myocardial resection were positive contributors to improved ventricular function, discharge, and survival. Preoperative evaluation with more cases and variables are needed to identify patients more likely to benefit from PLV.
Adult↗
Left ventricular volume reduction surgery: The 4th International Registry Report 2004.
BACKGROUND AND METHODS: An international registry of left ventricular volume reduction (LVVR) procedures, including partial left ventriculectomy, has been expanded, updated, and refined to include 568 cases voluntarily reported from 52 hospitals in 12 countries. RESULTS: Gender, age, ventricular dimension, ethnology, myocardial mass, presence or absence of mitral regurgitation, as well as transplant indication, had little effect on event-free survival, which was defined as either absence of death or ventricular failure requiring mechanical assist or transplantation. Poor preoperative patient condition such as New York Heart Association classification IV, depressed contractility and decompensation requiring an emergency procedure were associated with reduced event-free survival. Other risk factors included an early surgery date, lack of experience, dilated cardiomyopathy as the underlying pathology and extended myocardial resection. Performance of LVVR reached a peak by 1998, but was largely abandoned by 2001, except in Asia, where experienced institutes continue to perform it in patients in better condition with preserved myocardial contractility. CONCLUSION: Avoidance of risk factors appears to have contributed to the recent survival improvement and may help stratify patients for LVVR. While performance has been decreasing, the concept has been extended to other LVVR and less invasive procedures, which are now under clinical trials.
Adolescent↗
Static cardiomyoplasty with synthetic elastic net suppresses ventricular dilatation and dysfunction after myocardial infarction in the rat: an acute study.
BACKGROUND: Wrapping around the heart (static cardiomyoplasty) may help prevent a failing left ventricle (LV) from dilatation but may also interfere with diastolic relaxation, resulting in restrictive hemodynamics and diastolic heart failure. We developed a synthetic net with a dual elasticity and tested its effect early after induced myocardial infarction (MI) in the rat. METHODS: In rats undergoing occlusion of the left anterior descending artery (LAD) with and without cardiac wrapping, pressure-volume (PV) relationships were successively analyzed before, after intravenous volume load (saline 1% of body weight over 30 sec), and 10 to 40 minutes after LAD occlusion. In each situation, end-diastolic and end-systolic PV relationships were defined and LV size and function compared under standardized loading conditions. RESULTS: Ischemic increase in LV end-diastolic and end-systolic volumes was suppressed in a similar magnitude in NET with rats, resulting in preserved stroke volume and ejection fraction early after MI. While the presence of the net yielded a significant hemodynamic difference in response to acute volume load before ischemia, the difference was no longer apparent in the ischemic heart after LAD ligation. CONCLUSION: Static cardiomyoplasty using a synthetic elastic net significantly suppresses ischemic LV dilatation and dysfunction without restriction immediately after MI in the rat. The long-term result is pending. Net material and elasticity needs to be adjusted for optimal girdling effect, or greatest benefits with least functional compromise.
Animals↗
Partial left ventriculectomy in elderly patients not suitable for heart transplantation.
BACKGROUND: Although donor scarcity and intolerance to immunosuppression tend to exclude elderly patients from transplantation, partial left ventriculectomy (PLV) has been performed without bias against advanced age. METHODS: Among 392 patients undergoing PLV, 61 elderly patients aged 65 or older (> or =65) were compared with the rest of the patients in terms of underlying disease, postoperative course, and survival time. RESULTS: The aged patients (> or =65) compared to younger patients (<65), had ischemic disease (37.7% vs. 19.3%, p < 0.05) more frequently than cardiomyopathy (34.4% vs. 43.2%) or valvular disease (23.9% vs. 16.4%) and underwent lateral PLV (74% vs. 79%) more frequently than extended PLV (26% vs. 21%). Although the elderly patients required coronary bypass grafting more frequently (39.3% vs.17.2%, p < 0.05), surgical complexity was similar in terms of bypass time (63 minutes vs. 63 minutes) and percentage requiring cardiac arrest (31% vs. 44%). Despite advanced age, they required comparable ICU care (6.6 days vs. 5.4 days) and postoperative hospital stay (12 days vs. 11 days), resulting in a low but similar hospital survival (57% vs. 62%) and functional capacity after discharge (NYHA class 1.5 vs. 1.4). CONCLUSION: The results suggest that PLV can be performed in elderly patients (> or =65 years) with comparable risks and benefits with the younger patients, promoting its application in patients disqualified for heart transplantation because of age criteria.
Adolescent↗
Angiographic and hemodynamic follow-up of patients after partial left ventriculectomy.
Angiographic, Doppler-echocardiographic and hemodynamic studies early (+6 days) and late (+180 days) after partial left ventriculectomy (PLV) on 24 patients revealed that PLV decreased end-systolic volume (or dimension) more than the end-diastolic volume (or dimension), improving stroke volumes (or contractile excursion), and doubling ejection fraction (or fractional shortening). Results of PLV appeared to depend on a balance between improved systolic contractility and reduced diastolic performance. All these survivors had improved diastolic relaxation, suggesting myocardial viability is a prerequisite for PLV to be successful.
Adult↗
Combined reparative approaches for dilated failing ventricles.
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Cardiac Surgical Procedures↗