Kiyotaka Imoto

Decreased Tissue Inhibitor of Metalloproteinase-2/Matrix Metalloproteinase Ratio in the Acute Phase of Aortic Dissection

PurposeAortic dissection is characterized by fragility of the tunica media, and matrix metalloproteinases (MMPs) are enzymes that degrade the extracellular matrix of the aorta. This study examines MMPs in patients with acute aortic dissection (AAD) in an attempt to elucidate the mechanisms of their actions.MethodsEnzyme-linked immunosorbent assays were used to measure the quantification of MMP-2, MMP-9, and the tissue inhibitor of metalloproteinase (TIMP)-2 in 30 patients with AAD, 12 patients with abdominal aortic aneurysm (AAA), and 16 control (CON) patients who underwent coronary artery bypass grafting.ResultsMMP-2 and TIMP-2 were significantly lower in the AAD group than in the CON group, at 36 ± 19 vs 58 ± 30 (P ≪ 0.01) and at 21 ± 25 vs 216 ± 130 (P ≪ 0.001), respectively. The TIMP-2/MMP-2 ratio was 3.7 ± 1.7 in the CON group and 0.9 ± 0.8 in the AAD group (P ≪ 0.001 vs CON), and the TIMP-2/MMP-9 ratio was 200 ± 170 in the CON group and 37 ± 80 in the AAD group (P ≪ 0.001 vs CON).ConclusionLow TIMP-2/MMP-2 and TIMP-2/MMP-9 ratios might play an important role in the onset of aortic dissection, when the tunica media becomes fragile with chronic breakage and degradation of the extracellular matrix.

Optimal timing of surgery for active infective endocarditis with cerebral complications: a Japanese multicentre study

OBJECTIVES The aim of this study was to investigate the effect of the timing of valve surgery on the clinical outcomes of patients with active infective endocarditis (IE) accompanied by cerebral complications. METHODS We retrospectively analysed a cohort of 568 patients, comprising 118 with non-haemorrhagic cerebral infarction (CI), 54 with intracranial haemorrhage (ICH) and 396 without cerebral events (C; control), who underwent surgery for left-sided active IE in 15 Japanese institutes from 2000 to 2011. The mean age was 58.4 ± 16.9 years in the CI group; 54.5 ± 17.4 years in the ICH group and 56.9 ± 16.0 years in the C group. Clinical outcomes were analysed according to the timing of surgery after the diagnosis of CI or ICH was made. RESULTS In the CI group, there were 9 (7.6%) hospital deaths, 13 (11%) new cerebral events and 1 (0.8%) redo valve surgery. In the ICH group, there were 3 (5.6%) hospital deaths, 8 (14.8%) new cerebral events and 2 (3.7%) redo valve surgeries. In the C group, there were 36 (9.1%) hospital deaths, 23 (5.8%) new cerebral events and 9 (2.3%) redo valve surgeries. Risk factors for hospital death were prosthetic valve endocarditis (P = 0.045), high C-reactive protein (CRP; P < 0.001) and the elderly (P < 0.001) in the CI group. Delayed surgery (2 weeks after CI) seemed result in a higher incidence of hospital death in the CI group. Patients who had surgery between 15 and 28 days or after 29 days from the onset of CI had higher incidences of hospital death [odds ratio 5.90 (P = 0.107) and 4.92 (P = 0.137), respectively] compared with those who had surgery within 7 days. In the ICH group, risk factors for hospital death were high CRP (P = 0.002) and elderly (P < 0.001). Contrary to CI patients, patients who had surgery between 8 and 21 days or after 22 days after the onset of ICH had lower incidences of hospital death [odds ratio 0.79 (P = 0.843) and 0.12 (P = 0.200), respectively] compared with those who had surgery within 7 days. CONCLUSIONS Although statistically insignificant, early surgery in active IE patients with CI is safe, but very early surgery (within 7 days) should be avoided in patients with ICH.

Remodeling of the Bifurcation Asymmetry of Right Coronary Ventricular Branches in Hypertrophy

AbstractTo document the remodeling of the asymmetric branching pattern of the coronary right ventricular branches (RVBs) in right ventricular hypertrophy (RVH), we computed an asymmetry ratio, S, for the diameters and lengths of all vessels, defined as the ratio of the daughter diameters and lengths, respectively. We have previously induced RVH in pigs by pulmonary stenosis for five weeks. At autopsy, silicone elastomer casts of the right coronary arteries were made and the morphometric data on the branching pattern and vascular geometry of the RVB were collected. Data on smaller vessels were obtained from histological specimens while data on larger vessels were obtained from vascular casts. The results show that the diameter asymmetry ratio was significantly decreased in RVH hearts. The asymmetry ratios of diameters and lengths were used to compute the asymmetry ratios for vascular resistance and flow of the various daughter vessels. It was found that the degree of asymmetry of the resistance and flow were decreased, which implies that the flow heterogeneity at a bifurcation is decreased in the RVH hearts.

Ultrasonography and Lung Mechanics Can Diagnose Diaphragmatic Paralysis Quickly

Diaphragmatic paralysis after cardiovascular surgery requires early diagnosis prior to extubation. The effectiveness of ultrasonography and a lung mechanics assessment was evaluated. Paralysis of the diaphragm was diagnosed when the diaphragm failed to move or moved in a cephalad direction during inspiration. It was diagnosed in 3 of 40 patients (7.5%) who underwent cardiovascular surgery from 1998 to 1999. Patients were extubated when all parameters met the extubation criteria, irrespective of the presence or absence of diaphragmatic paralysis. One patient required prolonged assisted ventilation and died from mediastinitis on the 35th postoperative day. The other 2 patients required assisted ventilation for an additional 1–3 days. Ultrasonography and a lung mechanics assessment are effective tools for the early diagnosis of diaphragmatic paralysis and assessment of respiratory function after cardiovascular surgery.

Distal Aortic Perfusion and Cerebrospinal Fluid Drainage for Thoracoabdominal Aortic Repair

Objective: The purpose of this study was to evaluate the short-term results of thoracoabdominal repair using distal aortic perfusion and cerebrospinal fluid (CSF) drainage.

Sonographic Findings of Preserved Saphenous Veins in Primary Varicose Veins Patients

High ligation of the saphenous vein without stripping (HL) and selective stripping of upper part of the saphenous veins (SS ) have been performed to reduce surgical invasiveness of conventional varicose veins surgery and to preserve possible future graft materials for arterial reconstruction[1,2,3]. Aim of this study is to evaluate morphology and competence of preserved saphenous veins by sonography and Doppler flowmetry or Duplex scanning.