Mikio Ninomiya

Influence of PMEA-coated bypass circuits on perioperative inflammatory response.

BACKGROUND Poly(2-methoxyethylacrylate) (PMEA) is a new coating material, and several experimental studies have revealed excellent biocompatibility of PMEA-coated cardiopulmonary bypass circuits. The clinical utility of the PMEA-coated circuits was compared with that of uncoated circuits, focusing on perioperative inflammatory response. METHODS Twenty-two patients were randomized to PMEA-coated (group P; Capiox RX25; n = 11) or uncoated (group U; Capiox SX10; n = 11) circuit group, and underwent coronary artery bypass grafting and/or valve operations. The following markers, as well as clinical outcomes, were analyzed perioperatively: (a) complement activation by C3a (including C3a-desArg) concentrations; (b) leukocyte activation by polymorphonuclear-elastase concentrations; (c) acute phase inflammatory response by interleukin-6 concentrations; and (d) platelet preservation by number of platelets. RESULTS The maximal values of C3a and polymorphonuclear-elastase were significantly lower in group P than in group U. The intergroup difference of interleukin-6 was not significant. Although preservation of platelets was significantly better in group P until 1 hour after initiating cardiopulmonary bypass, no significant intergroup difference was observed thereafter. The duration of postoperative mechanical ventilation revealed no significant intergroup difference. CONCLUSIONS The PMEA-coated circuits exhibited better suppression of perioperative complement and leukocyte activation than the uncoated circuits. In addition, the price of the PMEA-coated circuits is the same as that of the uncoated circuits. Therefore, we judged that the clinical utility of the PMEA-coated circuits is superior to those of the uncoated circuits.

Local delivery of synthetic prostacycline agonist augments collateral growth and improves cardiac function in a swine chronic cardiac ischemia model.

AIMS It was reported that administration of angiogenic growth factors can augment collateral growth in ischemic tissues. It is assumed that angiogenic effects of cell transplantation may be mainly mediated by secretion of angiogenic cytokines. We tested feasibility of clinical use of ONO-1301, a synthetic small molecule that stimulates secretion of growth factors from various cell types, to treat patients with chronic myocardial ischemia. MAIN METHODS Effects of ONO-1301 on fibroblasts and endothelial cells were evaluated in vitro. We examined the efficacy of local delivery of ONO-1301 in models of rat hindlimb ischemia and swine chronic ischemic myocardium. KEY FINDINGS ONO-1301 stimulated hepatocyte growth factor secretion from human fibroblasts. ONO-1301 promoted vascular-like tube formation by endothelial cells in vitro. Direct injection of a slow-release form of ONO-1301 (SR-ONO) to rat hindlimb ischemic muscle enhanced perfusion recovery. In a swine cardiac ischemia model, direct injection of SR-ONO into the ischemic myocardium significantly augmented collateral formation (SR-ONO vs. control; 1.7+/-0.2 vs. 1.0+/-0.2 Rentrop score), with improved local ventricular wall motion, reduced enlargement of left ventricular diastolic volume (49.5+/-1.9 mL vs. 59.7+/-4.2 mL) and increased cardiac index (4.2+/-0.1 vs. 3.4+/-0.2 L/min/m(2)). Histological analysis revealed that SR-ONO suppressed fibrosis in ischemic tissue (collagen volume fraction; 7.5+/-1.1% vs. 12.8+/-2.2%) and enhanced neovascularization (capillary density, 275.6 vs. 159.3/mm(2); arterioles 36.6 vs. 25.5 /mm(2)). SIGNIFICANCE Local delivery of SR-ONO might be effective for therapeutic angiogenesis and propose that local administration of slow-release of synthetic small molecules represents new strategy for therapeutic angiogenesis.

Indication and Perioperative Management for Cardiac Surgery in Patients With Liver Cirrhosis : Our Experience With 3 Patients

Three patients with noncardiac Child A cirrhosis underwent cardiac surgery. All survived surgery, but 2 died during follow-up periods. A 61-year-old woman who underwent successful double valve replacement died of diabetic coma and severe acidosis due to intestinal necrosis 18 months later. A 57-year-old woman who underwent successful mitral valve replacement died of liver failure induced by heart failure 9 years later. A 45-year-old man who underwent coronary artery bypass grafting is doing well 18 months after discharge. Proper perioperative management, including high-flow cardiopulmonary bypass, pharmacological and mechanical circulatory support, and mechanical respiratory support prevented further, potentially lethal, hepatic dysfunction, leading to good early surgical results. We concluded that patients with Child A cirrhosis could tolerate cardiac surgery. Subsequent surgical results, however, were unsatisfactory, and more careful follow-up is necessary to obtain better late results.

Effects of lung metastasectomy on respiratory function.

OBJECTIVE The effects of lung metastasectomy on respiration were evaluated. SUBJECTS From 1961 to 1999, 203 patients underwent lung metastasectomy. Of these, 102 patients who had undergone only partial lung resection, had undergone sufficient respiratory function testing, and had not suffered from other lung disease were included. RESULTS Unilateral thoracoscopic surgery caused less decrease in percent vital capacity than surgery through a posterolateral thoracotomy, in both the early (rate of decrease: 16.2 +/- 9.1 vs. 33.0 +/- 12.0%, p < 0.01), and the late postoperative period (2.0 +/- 4.5 vs. 17.8 +/- 6.0%, p < 0.0001). Two thoracoscopic operations caused less decrease in percent vital capacity than 2 operations through a posterolateral thoracotomy (21.3 +/- 13.8 vs. 61.1 +/- 8.1%, p = 0.02). Bilateral metastasectomy through a median sternotomy caused less decrease in percent vital capacity than that through posterolateral thoracotomies (45.5 +/- 13.7 vs. 60.8 +/- 8.8%, p < 0.05). Four (36%) of 11 patients who had undergone 3 or more metastasectomies exhibited dyspnea of degree 3 or higher on the Hugh-Jones classification. CONCLUSIONS Thoracoscopic metastasectomy and metastasectomy through a median sternotomy caused less restrictive respiratory dysfunction than metastasectomy through a posterolateral thoracotomy. Since metastatic lung disease often necessitates repeated metastasectomy, and repeated metastasectomy often causes severe restrictive respiratory dysfunction, metastasectomy should be performed with a less invasive procedure.

Left atrial dissection after double valve replacement

Left atrial dissection, a rare complication occurring mainly after mitral repair, is reported after double valve replacement in a patient with a connective tissue disease. A 63-year-old woman with systemic sclerosis underwent double valve replacement. Laceration of the tissue between the two mechanical prostheses and dissection of the left atrial wall emerged postoperatively and regurgitation through the dissection caused heart failure, which later improved without surgery. The possible causes of the dissection were thought to be shear forces against the tissue between the two prostheses and tissue fragility due to systemic sclerosis and corticosteroid therapy.

Ischemic heart disease associated with protein C deficiency

Three patients of ischemic heart disease associated with protein C deficiency are reported. Although delayed diagnosis of protein C deficiency resulted in the failure of repeated interventions, coronary artery bypass grafting performed after making the correct diagnosis has led to satisfactory mid-term results under strict anticoagulation therapy. The level of protein C should be measured more frequently in the field of ischemic heart disease and earlier diagnosis of its deficiency should be made, because measurement of protein C does not cost much.

Conventional repair and operative stent-grafting for acute and chronic aortic dissection

Conventional graft replacement of the ascending aorta and surgically endovascular stent-grafting of the proximal descending aorta were performed concomitantly in a 82-year-old woman with an acute DeBakey type II aortic dissection and a chronic DeBakey type IIIb aortic dissection. Postoperative computed tomography and angiography showed the adequately replaced ascending-aortic prosthesis, the well-expanded stent-graft, and the thrombosed false lumen in the descending aorta.

Valve-sparing operation for aortic root aneurysm in patients with bicuspid aortic valve

Aortic root aneurysms are not rare in patients with bicuspid aortic valve, but valve-sparing operations to treat them remain challenging. We describe our surgical method of reconstructing only two commissures, which is extremely simple and easy to reproduce without aortic stenosis.

Hypertrophic obstructive cardiomyopathy associated with mitral regurgitation due to infective endocarditis.

A 25-year-old woman treated for hypertrophic obstructive cardiomyopathy and suffering from mitral regurgitation due to infective endocarditis was referred to our department for surgery. Preoperative examinations revealed asymmetric septal hypertrophy, a large left ventricular outflow gradient (100 mmHg), and perforation of the anterior mitral leaflet resulting in severe mitral regurgitation. The entire mitral complex was resected and septal myectomy conducted to dilate the left ventricle. A bioprosthetic valve was then implanted. Although postoperative heart failure was severe, cardiac function has gradually recovered. The left ventricular outflow gradient has decreased to 8 mmHg, the diastolic left ventricular diameter has increased from 26 to 30 mm, and her New York Heart Association classification has improved from IV to I.

Needle-guided mini-entry in video-assisted coronary artery bypass

In minimally invasive coronary artery bypass (MICAB), a video-assisted needle-guided technique was used to make a mini-thoracotomy or an access-port just above the target site in the left anterior descending coronary artery (LAD). After thoracoscopic preparation of the left internal thoracic artery (LITA) and pericardiotomy, a 7-cm, 23-gauge needle was used to examine the skin-point where the needle vertically penetrated the chest wall and thoracoscopically indicated the target site in the LAD. This point was used as the mid-point of the skin incision for a 6-cm thoracotomy (six cases) or a 33-mm access-port (four cases). Consequently, there was no conversion of approach except in the patient with pulmonary dysfunction, and each LITA-LAD anastomosis was completed directly through the mini-entry. There was no mortality and no procedure-related morbidity. Patency of each graft was confirmed within a week after surgery. After a mean follow-up period of 12.5+/-7.8 months, all of the patients except one, who died of stroke 1 year after surgery, are alive with no ischemic events. Although our experience is limited, the present video-assisted needle-guided technique can be a simple method to facilitate appropriate positioning of a mini-entry in MICAB to the LAD with a thoracoscopically prepared LITA graft.