Hajime Imura

One-stage coronary and abdominal aortic operation with or without cardiopulmonary bypass: early and midterm follow-up

BACKGROUND The aim of this study was to compare hospital, early, and late clinical outcomes for patients undergoing one-stage, coronary and abdominal aortic surgical intervention with and without cardiopulmonary bypass. METHODS From March 1990 to September 1999, 42 consecutive patients underwent combined operations at a single institution. Cardiopulmonary bypass and cardioplegic arrest were used during coronary revascularization in the first 20 patients (on-pump group), and the next 22 patients received the one-stage operations on the beating heart (off-pump group). RESULTS Baseline characteristics were similar between groups. Three cardiac-related hospital deaths occurred in the on-pump group and one such death in the off-pump group (p = 0.25). Cardiac-related events, pulmonary complications, inotropic support, blood loss and transfusion requirements, intensive care unit stay, and hospital stay were significantly reduced in the off-pump group (all, p < 0.05). The actuarial survival rates in the on-pump and off-pump groups were 80% and 95%, respectively, at 1 year (p = 0.13) and 75% and 89%, respectively, at 3 years (p = 0.22). Freedom from cardiac-related events at 1-year follow-up was 91% in the off-pump group and 65% in the on-pump group (p < 0.05). No difference in cardiac-related events between groups was observed at 3 years. CONCLUSIONS Off-pump coronary surgical procedures decrease postoperative complications in high-risk patients undergoing simultaneous coronary and abdominal aortic operations compared with the conventional one-stage procedure. The early benefits achieved with off-pump surgical intervention are not at the expense of the long-term clinical outcome.

Wavelength and Conduction Inhomogeneity in Each Atrium in Patients with Isolated Mitral Valve Disease and Atrial Fibrillation

AF in Mitral Valve Disease. Introduction: Patients with mitral valve disease frequently have atrial fibrillation (AF), and the left atrium is presumed to be the primary atrium that develops AF. However, it is still not clear whether the electrophysiologic abnormalities responsible for AF are confined to the left atrium in this subset of patients.

Simultaneous surgical correction of a common atrium and impure flutter

We performed surgical correction and treatment of a common atrium and chronic impure flutter using a computerized mapping system in a 49-year-old man. A reentrant circuit was observed to exist around the left atrial appendage. In contrast to the regular activation in the left atrium, the activation sequence of the right atrium was extremely chaotic. Cryolesions were applied to the area of the reentrant pathway. After the operation, sinus rhythm was restored.

Haemolytic anaemia due to stenosed double-reinforced grafts after surgical repaired aortic dissection

Haemolytic anaemia due to a stenosed graft is a rare complication after surgery for aortic dissection. We present the case of a patient with haemolytic anaemia and heart failure, who had undergone emergent ascending aorta replacement for type A acute aortic dissection 5 years earlier. Chest computed tomography revealed severe graft stenosis of the proximal anastomosis and transthoracic echocardiography showed severe aortic regurgitation. Surgical treatment was necessary because of heart failure and myocardial ischaemia due to haemolytic anaemia and aortic regurgitation. During the operation, we found an inner graft surrounded by an outer graft and a dilated lumen between the double-reinforced grafts compressing the inner graft. We successfully reconstructed the aortic root with a total arch replacement. To the best of our knowledge, there are no cases in which haemolytic anaemia and AR developed in a patient with acute aortic dissection surgically treated by such a mechanism.

Repair of an Abdominal Aortic Aneurysm with a Remarkably Dilated Meandering Artery: Report of a Case

A 73-year-old man on dialysis for chronic renal dysfunction was referred to our hospital for surgical treatment of an abdominal aortic aneurysm (AAA). Preoperative angiography showed a remarkably developed meandering artery branching from the inferior mesenteric artery (IMA). The superior mesenteric and celiac arteries were occluded at the origin, and all blood flow to the abdominal organs was apparently supplied by collateral circulation from the IMA. Considering the risk of mesenteric ischemia after aortic clamping in conjunction during surgery, we used a perfusion catheter with a 12-F balloon to create a shunt to the IMA from the subclavian artery. The operation was successful and the patient recovered uneventfully. We describe this surgical procedure for its effectiveness in preventing postoperative mesenteric ischemia in a rare case of an AAA with complex branching lesions.

Restoration of sinus rhythm and atrial transport function after the maze procedure: U lesion set versus box lesion set

OBJECTIVE In a U lesion set, the left atrium (LA) roof between the right and left superior pulmonary veins is not ablated, to allow activation to propagate across the posterior LA and to recruit this segment as a contractile atrial component. In contrast, the box lesion set isolates the entire posterior LA. METHODS To compare the two lesion sets, postoperative freedom from atrial fibrillation (AF) and LA transport function were examined in 402 patients who underwent surgery for AF with a U lesion (n = 329) or box lesion (n = 73) set. Patients who underwent pulmonary vein isolation alone or other simplified procedures were excluded from the study. LA transport function was quantified at 20 ± 33 months postoperatively by the ratio of peak velocity of the A wave to the E wave (peak A/E) of the transmitral Doppler flow. RESULTS In patients with long-standing persistent AF, freedom from AF was 85% with the U lesion set and 77% with the box lesion set at 5 years after the maze procedure, and 82% and 77%, respectively, at 10 years after the procedure. There was no significant difference between the U lesion set and box lesion set in patients with long-standing persistent AF (P = .30) and those with paroxysmal or persistent AF (P = .90). Proportional hazards analysis identified increased LA diameter (P = .003) and long-standing persistent AF (P = .03), but not the type of lesion set (P = .51), as predictive of postoperative AF recurrence. The postoperative peak A/E was significantly greater after the U lesion set than after the box lesion set (0.42 ± 0.22 vs 0.23 ± 0.17), and multiple regression analysis demonstrated that the type of lesion set and preoperative LA diameter significantly affected postoperative A/E. CONCLUSIONS The U lesion set restores sinus rhythm frequently as the box lesion set and provides better LA transport function. A dilated LA is a risk factor for postoperative recurrence of AF and poor postoperative LA transport function.

Acute Type-A aortic dissection with patent false lumen through to the abdominal aorta: effects of a conventional elephant trunk on malperfusion syndromes and narrowed true lumen

Background: Narrowed true lumen and patent false lumen through to the terminal aorta is a high-risk condition for malperfusion syndromes (MS) in acute type-A aortic dissection. It is important to ascertain how the true and false lumens behave after surgery. Patients and Methods: We retrospectively investigated 45 patients with this pathology. The true lumen sizes at the narrowest levels above and below the superior mesenteric artery were followed by computed tomography after surgery (0-36 months). Results: Thirty-seven MS were seen in 23 patients. Hospital mortality was 8.9%. The narrowed true lumen was not enlarged in the first 6 months with a patent false lumen. The elephant trunk procedure did not improve the true lumen size. An extremely narrowed (≤3mm) true lumen was associated with a significantly high incidence of MS and mortality. Conclusions: High incidences of MS were observed in this particular pathology. An extremely narrowed true lumen was accompanied by a high incidence of MS and mortality.

Preoperative evaluation of the saphenous vein by 3-D contrastless computed tomography

Volume-rendering computed tomography (CT) without contrast medium has clearly demonstrated the 3-D mapping of the saphenous vein (SV). Contrastless volume-rendering CT was used to preoperatively evaluate the SV anatomy before coronary artery bypass grafting (CABG). This technique was useful for atypical anatomical variations, such as partial duplication of SV (Case 1) or varicose veins (Case 2). Volume-rendering CT may also help with redo CABG (to determine remaining SV) or during endoscopic SV harvesting with restricted view. Volume-rendering CT is an objective, less time-consuming modality to evaluate the SV preoperatively and may be less invasive in terms of avoiding unnecessary skin incision.

Two-Patch Repair for Atrioventricular Septal Defect With Mitral Aneurysm

We experienced an unusual case of partial atrioventricular septal defect in an elderly patient. A preoperative ultrasonic cardiogram revealed the mitral leaflet pouching toward the right atrium and suggested the presence of a ventricular septal defect underneath the atrioventricular valve. The mitral aneurysm was diagnosed as a septal aneurysm on preoperative ultrasonic cardiogram. A crescent-shaped Dacron patch (InterVascular S. A., La Ciotat Cedex, France) was placed beneath the atrioventricular valve to prevent rupture of the mitral aneurysm and support the anterior mitral leaflet by creating a new annulus. We believe that this is the first report describing this type of mitral aneurysm and its surgical repair.

Cardioprotection during Adult and Pediatric Open Heart Surgery

Myocardial reperfusion damage following cardioplegic ischemic arrest is a key determinant of postoperative organ functional recovery, morbidity, and mortality in adult and pediatric patients undergoing open heart surgery. The vulnerability of the diseased heart to ischemia and reperfusion is different for different pathologies or associated disease (e.g., coronary disease, hypertrophy, diabetes, etc.) and different age (e.g., neonate, infant, children, and adult). These differences and the changing nature of adult patients (e.g., aging population) present a major challenge in translating novel interventions. Thus far, hyperkalemic cardioplegic solutions, which by arresting the heart preserve substrates and delay the onset of the ischaemic insult, remain the corner stone for cardioprotection during open heart surgery. Ongoing strategies to improve myocardial protection include the inclusion of various additives that aim at reducing the damaging effects of ischemia and reperfusion (e.g., calcium overload, metabolic derangement, and accumulation of reactive oxygen species). Recent and novel strategies have also included gene and cell therapies. In this special issue, several reviews and research articles have provided novel interpretations and data to help in the search for designing an optimal strategy to reduce myocardial injury during cardiac surgery and thus improve long term cardiac functional recovery. For example, a strong argument has been made for the potential role of inhibiting monoamine oxidases (MAOs) in cardioprotective strategies (O. M. Duicu et al.). The activity of this enzyme is linked to oxidative stress and the central role of mitochondria in disease and death. It is therefore recommended to test this in a prospective study in cardiac patients with and without diabetes undergoing heart surgery. In their review, A. Habertheuer et al. point out the importance of the changing characteristics of cardiac surgery patients and propose that better understanding of the associated molecular changes could offer new directions for the design of new more appropriate cardioprotective regimens. N. Lakusic et al. address the very interesting topic linking changes in heart rate variability after coronary artery bypass grafting to postoperative morbidity. There is clearly an important role of the autonomic nervous system in the consequences of ischemia/reperfusion injury. They emphasize the fact that several studies have shown a reduction in heart rate variability after coronary artery bypass grafting surgery. They point out the need for a study investigating the link between decreased heart rate variability and the outcome of coronary artery bypass graft surgery patients. R. Wagner et al. focus on myocardial conditioning and its therapeutic cardioprotective potential. In this respect, they point out that despite the extensive experimental studies, almost all cardioprotective therapies have failed in the third phase of clinical trials. They propose that the evolutionary young cellular mechanisms of protection against oxygen handling are not very robust. An experimental study by T. Sato et al. suggests that insulin activated survival pathways facilitate preservation of cardiac contractility during ischemia-reperfusion injury in the isolated rat heart in a way that could be similar to conditioning-induced protection. E. W. Kuhn et al. present data from a pilot trial investigating the effect of cardioplegia temperature on endothelial injury in patients undergoing on-pump coronary artery bypass graft surgery. They demonstrate perioperative endothelial injury and showed that cold is better than warm blood cardioplegia. A relevant review by Q. Yang et al. points out that coronary endothelial dysfunction occurring during cardiac surgery could be due to functional alteration of endothelial channels and that these channels could be potential targets for endothelial protection during cardiac surgery. The developing heart and myocardial protection during pediatric cardiac surgery is an area in need of more research. A. Mokhtari and M. Lewis address the very important issue of controlled reoxygenation in cyanotic paediatric patients undergoing open heart surgery. The finding that cardiopulmonary bypass triggers cardiac injury prior to cardioplegic arrest [1] highlights the need for controlling reoxygenation during cardiopulmonary bypass. Recent studies have successfully demonstrated the benefits of this approach [2]. M. Cherif et al. investigated the involvement of Gab1 (Grb2 associated binding protein 1), a protein required for fibroblast cell survival and in maintaining cardiac function. They showed that this protein was upregulated in hearts of cyanotic children possibly as part of survival signaling response to hypoxia. Finally, M. Shirakawa et al. have provided evidence showing that propofol at a clinically relevant concentration is cardioprotective in the immature heart. This anesthetic has already been shown to be protective in adult models when used in cardioplegia [3] and has been included in cardioplegic solutions during surgery in patients with isolated coronary artery bypass grafting or aortic valve replacement using cardiopulmonary bypass [4]. We hope that this special issue provides the readers with new insights into different approaches used to protect the adult and the pediatric heart against the damaging effects of ischemic and reperfusion injury. If anything, the work described emphasizes the need for a more comprehensive strategy taking into account pathologies and age. M-Saadeh Suleiman Malcolm Underwood Hajime Imura Massimo Caputo