Current Status of Off-Pump Coronary Artery Bypass.

PURPOSE: Off-pump coronary arterial bypass grafting (OPCAB) has become a common practice for coronary artery bypass grafting (CABG) in Japan, with approximately 65% CABG procedures currently being performed using OPCAB. However, it is unclear whether OPCAB is superior in terms of associated mortality, incidence of complications, graft patency rate, and long-term outcomes compared with conventional CABG (CCABG). METHODS: Literature consideration was performed, mainly based on observational studies involving large samples and randomized controlled trials (RCTs). RESULTS: Many RCTs indicated that the acute-phase and long-term mortality rates were comparable between CCABG and OPCAB or that OPCAB was inferior to CCABG. In contrast, many observational studies indicated that OPCAB was superior to CCABG. CONCLUSION: CABG is a delicate procedure, the outcomes of which vary in accordance with the patient's condition as well as the level of expertise of the associated institution and surgeon. In the future, we hope that reports will emerge with excellent results, including long-term results, from Japanese institutions experienced in performing OPCAB.

Randomized clinical trial of an elastomeric sealant for hemostasis in thoracic aortic surgery.

OBJECTIVES: This study aimed to demonstrate the efficacy and safety of a newly developed elastomeric sealant, which does not require any blood coagulation system to exert its effect, during thoracic aortic surgery. METHODS: This is a multicenter, randomized study conducted in six hospitals in Japan. A total of 81 patients undergoing replacement surgery of a thoracic aortic aneurysm using cardiopulmonary bypass were randomized with a ratio of 2-:1 for those patients designated to receive the sealant (Group S, 54 patients) or those without the usage of the sealant (Group C, 27 patients). The primary endpoints were bleeding from each anastomosis at two time points: (1) immediately before applying protamine and (2) 15 min after applying protamine. The patients were followed for 6 months. RESULTS: The number of anastomoses checked for bleeding was 196 in Group S and 117 in Group C. Before protamine sulfate administration, complete hemostasis was obtained in 155 anastomoses (79%) in Group S compared to 45 anastomoses (38%) in Group C (p < 0.001). Fifteen minutes after the administration of protamine sulfate infusion, bleeding stopped completely in 173 anastomoses (88%) in Group S and in 71 anastomoses (61%, p < 0.001) in Group C. Between the two groups, there were no marked differences in the patient background or in the incidence of major adverse events. CONCLUSIONS: The sealant is effective in achieving hemostasis, even under fully heparinized conditions. The novel sealant is safe and effective in thoracic aortic surgery, one of the most demanding surgical situations for hemostasis.

Clinicopathological study on penetrating atherosclerotic ulcers and aortic dissection: distinct pattern of development of initial event.

An intimal tear is responsible for the development of aortic dissection (AD). Plaque rupture is thought to progress to a penetrating atherosclerotic ulcer (PAU). However, the influences of mechanical stress and atherosclerosis on the intimal tear of AD and plaque rupture of PAU have not been fully understood. We enrolled 27 patients with AD [67.6 ± 11.2 years, female/male (F/M) 12/15] and 10 patients with PAU (71.0 ± 8.64 years, F/M 2/8) who underwent aortic reconstructive surgery in our hospital between 2007 and 2011. We analyzed the clinical data and morphological features of these patients and discuss the role of mechanical stress in the initial event. On clinical examination, hypertension was frequently observed in the patients of both the AD (77.8 %) and PAU groups (90.0 %), while hypercholesterolemia was significantly more prevalent in the PAU group (90.0 %) than in the AD (22.2 %) group. Most lesions of AD (96.3 %) were found in the ascending aorta up to the aortic arch, while those of PAU (90.0 %) were found in the descending and abdominal aortas. On pathological examination, the entrance tear was found in 21 (77.8 %) of the 27 patients with AD, and histologically comprised nonatherosclerotic intima and media. In contrast, the entrance tear was considered as plaque ulcer in 8 (80.0 %) of the 10 patients with PAU. The patients with PAU showed a significantly higher prevalence of soft plaque, complicated lesions, and medial fibrosis than those with AD, whereas patients with AD showed no complicated lesions and had a significantly higher prevalence of cystic medial necrosis than those with PAU. The present study suggests that less atherosclerosis and impairment of media could proceed to intimal tear formation in AD and that the disruption of the fibrous cap could cause the plaque ulcer of PAU.

[Coronary Artery Bypass Grafting and Biventricular Pacing for Severe Heart Failure due to Dilated Cardiomyopathy].

A 57-year-old man was diagnosed with dilated cardiomyopathy and coronary stenosis. His electrocardiogram showed a complete left bundle branch block and a prolonged QRS interval. As appropriate medical therapy improved his symptoms, he did not visit out-patient clinic after discharge. A year later, he presented with exertional chest oppression and was readmitted with severe heart failure. Although medical therapy was provided, his condition did not improve. Left ventricular systolic dysfunction and stenosis of the left anterior descending artery were aggravated. We performed coronary artery bypass grafting and biventricular pacing with surgical epicardial leads, which led to improvement in left ventricular systolic function. We consider that biventricular pacing with surgical epicardial leads is a potential option in cases of open heart surgery requiring cardiac resynchronization therapy for severe left ventricular systolic dysfunction.

Age-related distensibility and histology of the ascending aorta in elderly patients with acute aortic dissection.

Degradation and fragmentation of elastic fibers in the media dilate the aortic wall excessively in patients with acute Stanford type A aortic dissection (AD). Such dilatation occurs not via aortic stiffening, which is diagnosed using imaging under physiological loading, but due to the abovementioned intrinsic changes in elastic fibers, which can be detected at the low-stress region of the stress-strain relationship. Our objective is to determine an age-related correlation between distensibility and histology. We conducted uniaxial stretching tests and a histological evaluation of the ascending aorta (AA) using AD samples obtained at surgery from 9 elderly patients (aged 52-85 yr), with no heritable connective tissue disorders, and control (CN) samples from 10 subjects at autopsy (aged 56-86 yr). We compared the distensibility, or an increase in strain for the uniaxial tensile stress of 0-50 kPa, between the AD and CN groups, and correlated it with age and histology. Distensibility was significantly greater in the AD than that in the CN group (p=0.030), but elastin content was significantly lower (p=0.0025). The positive correlation between distensibility and elastin content in CN samples suggests that the distensibility increases with elastic fiber histological abnormalities. The age-matched collagen content decreased with the age of the patients, and did not differ between the AD and CN groups. The age-matched distensibility in the AD and CN groups decreased and became closer with aging. Such intrinsic properties should be considered during imaging to assess distensibility in patients with AD.

Four-stitch side-to-side anastomosis for sequential coronary artery bypass grafting.

Sequential bypass (SB) is an effective method of implementing complete myocardial revascularization of complex coronary stenoses. The SB allows a single graft to be used for bypass in several locations, which facilitates multi-branch revascularization. We have developed a simple SB technique, four-stitch side-to-side anastomosis, and report its clinical effectiveness in 428 patients.

[Surgical excision of left atrial myxoma shortly after cerebral embolism;report of a case].

A 48-year-old male visited the emergency room suffering from acute dysarthria and right hemiplegia. Brain magnetic resonance imaging (MRI) revealed multiple cerebral infarctions. Echocardiography showed a mass in the left atrium. He was diagnosed with cerebral embolism due to left atrial myxoma. Open heart surgery immediately after the attack is generally considered contraindicated because of such problems as hemorrhagic infarction or brain edema. However, relapse of embolism may make the condition worse and miss the timing of surgery. Eventually, we electively performed excision of the myxoma 20 days after the onset of cerebral infarction. The postoperative course was uneventful. This is a report about a rare case of open heart surgery shortly after the attack. The indication and the appropriate timing of open heart surgery following cerebral embolism were discussed.

Preventive effect of intraoperative landiolol administration on atrial fibrillation after off-pump coronary artery bypass grafting.

INTRODUCTION: Postoperative atrial fibrillation (AF) is a common complication of cardiac surgery that is associated with an increased incidence of other complications. This study evaluated the safety and efficacy of landiolol hydrochloride--an ultrashort-acting ß1-selective blocker and highly regulated drug, positioned as a class 1 antiarrhythmic in Japan guidelines--for the prevention of AF after off-pump coronary artery bypass grafting (CABG). METHODS: Between January 2011 and November 2013, 116 patients underwent CABG at Fukuoka University Hospital. They were divided into two groups: group L consisted of patients who were administered landiolol hydrochloride at 2 µg/kg/min after completion of all distal anastomoses; group C was the control group consisting of patients who were not administered landiolol. Patient backgrounds, intraoperative variables and incidence of postoperative complications were compared. RESULTS: No significant between-group differences were observed in patient backgrounds or incidence of complications other than postoperative AF, which occurred significantly less frequently in group L. After administration of landiolol, heart rate decreased but no change was observed in arterial pressure or other parameters, and patient hemodynamics remained stable. CONCLUSION: Intraoperative and perioperative administration of low-dose landiolol has a preventive effect on the development of AF after CABG surgery.

Direct and transapical central cannulation for acute type a aortic dissection.

OBJECTIVE: The choice of cannulation site for the treatment of acute Stanford type A aortic dissection is much debated. We believe that central cannulation is quick to perform, easy to use, and safe to manage acute type A aortic dissection. MATERIALS AND METHODS: We retrospectively investigated 26 cases of acute aortic dissection performed using two different central cannulation methods between April 2011 and March 2012. Direct ascending aortic cannulation was performed using the Seldinger technique in 20 patients, and transapical ascending aortic cannulation was performed in six patients in whom puncture was difficult. RESULTS: Patients were 21-86 years old (mean age, 67 years). The surgical techniques used to treat aortic dissection were hemiarch repair in 21 patients and total arch replacement in 5 patients. The mean length of surgery was 393 min. One death (3.8%) was attributed to intestinal ischemia. CONCLUSION: During surgery for acute aortic dissection, central cannulation using either transapical or direct puncture can be performed quickly and safely, and satisfactory short-term outcomes can be obtained. Because acute aortic dissection can present with various conditions, there is no single perfect surgical or cannulation method; therefore, the choice of surgical procedure should be individualized for each patient.

GM-CSF treated F4/80+ BMCs improve murine hind limb ischemia similar to M-CSF differentiated macrophages.

Novel cell therapy is required to treat critical limb ischemia (CLI) as many current approaches require repeated aspiration of bone marrow cells (BMCs). The use of cultured BMCs can reduce the total number of injections required and were shown to induce therapeutic angiogenesis in a murine model of hind limb ischemia. Blood flow recovery was significantly improved in mice treated with granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent BMCs that secreted inflammatory cytokines. Angiogenesis, lymphangiogenesis, and blood flow recovery ratio were significantly higher in the GM-CSF-cultured F4/80+ macrophage (GM-Mø)-treated group compared with controls. Furthermore, Foxp3+ cell numbers and tissue IL-10 concentrations were significantly increased compared with controls. There was no significant difference in blood flow recovery between GM-Mø and M-CSF-cultured F4/80+ macrophages (M-Mø). Thus, GM-Mø were associated with improved blood flow in hind limb ischemia similar to M-Mø. The selective methods of culturing and treating GM-Mø cells similar to M-Mø cells could be used clinically to help resolve the large number of cells required for BMC treatment of CLI. This study demonstrates a novel cell therapy for CLI that can be used in conjunction with conventional therapy including percutaneous intervention and surgical bypass.

A case of type-2 endoleak from a bronchial artery after endovascular aortic repair for Kommerell diverticulum.

We describe a case of type-2 bronchial artery endoleak after endovascular aortic repair of Kommerell diverticulum (KD) involving right-sided aortic arch and aberrant left subclavian artery (LSA). A 68-year-old woman underwent an endovascular repair of KD with an aberrant LSA in our hospital. Follow-up computed tomography (CT) at 6 months after the procedure showed an endoleak. Digital subtraction angiography revealed a type-2 endoleak from a bronchial artery, but no type-1 or type-2 endoleak from the aberrant left subclavian artery. We performed coil embolization of the KD and the left subclavian artery. The endoleak disappeared in the postoperative CT.

Safety and efficacy of ascending aorta cannulation during repair of acute type A aortic dissection (PA29-04): "Presented at the 65th Annual Scientific Meeting of the Japanese Association for Thoracic Surgery".

OBJECTIVE: Antegrade central perfusion for acute Stanford type A aortic dissection prevents malperfusion and retrograde cerebral embolism during cardiopulmonary bypass. Prompt establishment of antegrade perfusion via the ascending aorta may improve surgical results of type A dissections, especially in situations of hemodynamic instability. Thus, we evaluated the safety and efficacy of cannulation of the dissected ascending aorta in acute type A dissection. METHODS: We reviewed the medical charts of patients undergoing repair of acute ascending aortic dissection (n = 52) from April 2010 to April 2013. Cannulation was accomplished in 29 patients via the ascending aorta (central) and in 23 patients via the femoral or axillary artery (peripheral). The ascending aorta was routinely cannulated using Seldinger technique under epiaortic ultrasound guidance. Comorbidities, mortality, complications, and durations of hospital stays were compared for the groups. RESULTS: In all cases, routine cannulation of the ascending aorta was safely performed with no resultant malperfusion or thromboembolism. Mean operative duration, cardiopulmonary bypass time, intubation time, and intensive care unit stay were significantly shorter in the central group. Two patients (6.8 %) in the central group died compared with four patients (17.3 %) in the peripheral group (P = 0.005). CONCLUSIONS: Antegrade central perfusion via the ascending aorta, a simple and safe technique that enables rapid establishment of antegrade systemic perfusion, was as safe as peripheral cannulation in patients with type A acute aortic dissection.

Off-pump coronary artery bypass: techniques, pitfalls, and results.

In coronary artery bypass grafting (CABG), coronary artery anastomosis is generally performed under cardiac arrest using cardiopulmonary bypass (CPB). To avoid the invasiveness of CPB, off-pump coronary artery bypass (OPCAB) is currently also used. In Japan, in particular, OPCAB now accounts for 60 % of all CABG operations and has become a standard surgical procedure. We herein provide a discussion of OPCAB. The goals of coronary artery bypass surgery are to achieve complete revascularization and maintain a high rate of graft patency for the long term. This requires stable exposure of the coronary arteries, including those located on the posterior surface of the heart and the formation of good-quality anastomoses. Achieving this depends not only on the competency of the individual surgeon, but also on smooth and effective teamwork among everyone involved, including the other surgeons, anesthetists, clinical technicians, and nurses. It is important for surgeons and surgical teams to examine their own outcomes and engage in self-scrutiny in an endeavor to improve these outcomes.

Vascular endothelial growth factor-C derived from CD11b+ cells induces therapeutic improvements in a murine model of hind limb ischemia.

OBJECTIVE: The use of bone marrow cells (BMCs) in therapeutic angiogenesis has been studied extensively. However, the critical paracrine effects of this treatment are still unclear. Therefore, we studied autotransfusable cells that produce vascular endothelial growth factor (VEGF), especially VEGF-C. METHODS: Male C57BL/6 mice with hind limb ischemia were administered intramuscular injections of phosphate-buffered saline as controls, or unsorted BMCs, sorted CD11b(+), or CD11b(-) cells from BMCs, and recombinant VEGF-C. To evaluate the treatments, perfusion was measured by laser Doppler scanning performed on days 0, 1, 3, 7, 14, 21, and 28. A functional assay was performed in parallel, with mice traversing an enclosed walkway. Capillary density was determined by directly counting vessels stained positive with von Willebrand factor at individual time points. Lymphangiogenesis was assessed by LYVE-1 positive cells. RESULTS: Postischemic recovery of hind limb perfusion significantly improved in BMC, CD11b(+), and VEGF-C treatment groups compared with the control groups, as assessed by laser Doppler scanning. On early operative days 1 and 3, the blood flow recovery ratio was higher in the CD11b(+)-treated group compared with BMC and VEGF-C treatment groups. In the functional assay, the VEGF-C group dramatically recovered compared with the control group. The capillary/myofiber ratio in the thigh muscle and number of LYVE-1 positive cells was higher in the CD11b(+) and VEGF-C groups than in controls. Furthermore, expression of VEGF-A, VEGF-C, and VEGF receptor messenger ribonucleic acid and protein was observed in CD11b(+) cells. CONCLUSIONS: The VEGF-C derived from CD11b(+) cells play a critical role in angiogenesis and lymphangiogenesis in a murine model of hind limb ischemia. Consequently, treatment with self-CD11b(+) cells accelerated recovery from ischemia and may be a promising therapeutic strategy for peripheral arterial disease patients.

Effects of gender and aging in patients who undergo coronary artery bypass grafting: from the FU-Registry.

BACKGROUND: It is unclear whether gender and aging influence the characteristics of patients who undergo coronary artery bypass grafting (CABG). METHODS: We retrospectively reviewed a clinical database of 1,498 patients (male/female = 1133/365, age 67 ± 9 years) who underwent CABG at Fukuoka University Hospital from 1994 to 2010. RESULTS: Male showed significantly younger, higher percentages (%) of smoking and hyperuricemia (HU), higher levels of serum creatinine, and lower % hypertension (HT) and diabetes mellitus (DM), and lower levels of left ventricular ejection fraction than female. In multivariate analysis, all parameters identified independent variables associated with the gender difference. Next, we divided the patients into 5 groups according to age, and each group was then separated by gender. The % of males significantly decreased with aging, whereas % female significantly increased. Although % smoking and estimated glomerular filtration rate (eGFR), and body mass index (BMI) in all patients, males and females significantly decreased with aging, HU, left ventricular end diastolic pressure and the number of significantly stenosed coronary vessels were not associated with gender or aging. Interestingly, % HT in all patients and males significantly increased with aging, whereas that in females was not associated with aging. Serum low-density lipoprotein cholesterol levels in males significantly decreased with aging, while those in all patients and females were not associated with aging. In this contemporary data set, the decreases in % smoking and eGFR with aging were common characteristics in male and female patients. In addition, there were gender and aging differences in % smoking, % HT, BMI and eGFR, whereas no differences were observed in % DM, % dyslipidemia or % HU. CONCLUSIONS: Before CABG, high-risk patients with coronary artery disease who is going to undergo CABG may need to be managed more strictly considering to gender and age to avoid CABG.

[Ischemic stroke induced by a left atrial myxoma].

We reported a case of ischemic stroke induced by a left atrial myxoma. A 76-year-old man was found unconscious and transferred to the emergency ward in our hospital. He experienced consciousness disturbance, motor dominant aphasia, and severe right hemiparesis. His neurological and radiological findings indicated that he had ischemic stroke and was eligible to undergo intravenous thrombolysis. Alteplase was administrated 155 min after the onset of stroke. Intracerebral hemorrhage was not seen 24h after thrombolysis. A tumor in the left atrium was detected on transthoracic echocardiography, and this finding suggested that the tumor was a myxoma. Although cardiac surgery was scheduled, hemorrhagic transformation was found on day 11, which made us postpone the surgery. After the hemorrhage was disappeared, the tumor was resected by open-heart surgery and it was confirmed to be a myxoma. Neither his neurological symptom nor intracerebral hemorrhage was not deteriorated after the operation. Thrombolytic treatment seemed a safe option for ischemic stroke caused by left atrial myxoma. However, we should carefully monitor the extent of anticoagulation therapy because hemorrhagic transformation might alter the timing of surgery for tumor resection.

Safety and efficacy of an ultrashort-acting ß1-blocker on left ventricular dysfunction.

Landiolol hydrochloride, an ultrashort-acting ß1-selective blocker, is a highly regulated drug. This study evaluated the safety and efficacy of this drug for cases of coronary artery bypass grafting (CABG) with left ventricular dysfunction. Between September 2006 and August 2009, 32 patients with a left ventricular ejection fraction of <40% underwent CABG. Two groups of patients, a group administered landiolol hydrochloride and a control group not administered this drug, were compared. The administration of landiolol hydrochloride was initiated at 1 µg/kg per minute (γ) after cardiopulmonary bypass in on-pump cases and after completion of all the distal anastomoses in off-pump cases. We observed no significant differences between the groups with respect to preoperative patient background or incidences of complications, except for postoperative atrial fibrillation. The heart rate decreased significantly 30 minutes after landiolol hydrochloride administration, but no change was observed in arterial pressure. No change was observed in other parameters; the hemodynamics were stable. The occurrence of atrial fibrillation during the intensive care unit stay (during landiolol hydrochloride administration) was significantly lower in the administration group. The difference remained significant after multiple logistic regression analysis; landiolol hydrochloride was the sole inhibitory factor.