Naoki Masaki

Differential diagnosis and management of a mural mass in the aortic arch

From the Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, Seiryocho, Aoba-ku, Sendai; and Department of Cardiovascular Surgery, Hachinohe City Hospital, 1 Bishamontai, Tamukai, Hachinohe-city, Aomori, Japan. Disclosures: Authors have nothing to disclose with regard to commercial support. Received for publication Oct 21, 2016; revisions received Dec 5, 2016; accepted for publication Dec 18, 2016. Address for reprints: Naoki Masaki, MD, Seiryocho, Aoba-ku, Sendai 980-8574, Japan (E-mail: n.masaki@med. tohoku.ac.jp). J Thorac Cardiovasc Surg 2017;-:e1-3 0022-5223/

Evidence of Pulmonary Vascular Reverse Remodeling After Pulmonary Artery Banding Performed in Early Infancy in Patients With Congenital Heart Defects

36.00 Copyright 2017 by The American Association for Thoracic Surgery http://dx.doi.org/10.1016/j.jtcvs.2016.12.037

Aortic Valve Replacement for Patients with Functioning Internal Mammalian Artery Grafts

BACKGROUND Histomorphometric evidence of the effect of pulmonary artery banding (PAB) in infancy on pulmonary vascular reverse remodeling has not been fully described.Methods and Results:We retrospectively reviewed 34 patients who underwent serial lung biopsies before and after PAB.Index of pulmonary vascular disease (IPVD) as a measure of the degree of progression of pulmonary arteriopathy significantly decreased after PAB (1.22±0.25 at 1st and 1.13±0.21 at 2nd biopsy, P=0.04). Additionally,DR=100 µmas an indicator of medial thickness of pulmonary arteries significantly decreased after PAB (15.6±3.7 at 1st and 11.4±2.6 at 2nd biopsy, P<0.0001). Patients were divided into 3 groups by age at PAB: <3 months (Group 1), between 3 and 6 months (Group 2), and >6 months (Group 3). The average secondDR=100 µmof groups 1 and 2 was significantly lower than that of group 3 (11.1±2.2 and 9.8±2.0 vs. 14.9±2.8, respectively; P<0.0001). Additionally, the second IPVD was also significantly lower in groups 1 and 2 than in group 3 (1.1±0.2 and 1.1±0.2 vs. 1.3±0.4, respectively; P=0.02). CONCLUSIONS Histomorphometric evidence of post-PAB pulmonary vascular reverse remodeling is robust. The magnitude of vascular reversibility is pronounced when PAB is performed before 6 months of age.

Oesophageal mucosal blood flow changes after thoracic endovascular stent graft implantation using a novel sensor probe

Aortic valve replacement (AVR) for patients with functioning internal mammalian artery (ITA) grafts is technically challenging, and the optimal treatment strategy for these situations remains controversial. Here, we report five cases of AVR with ITA graft using continuous retrograde cardioplegia in addition to moderate hypothermia without the clamping of ITA and discuss the management of these cases.

Aortic Valve Infective Endocarditis with an Annular Abscess

OBJECTIVES Secondary aorto-oesophageal fistula is a rare, lethal complication occurring after thoracic endovascular aneurysmal repair. The cause of secondary aorto-oesophageal fistula is unknown, but a reduction in local oesophageal mucosal blood flow (OMBF) may be a basis for such a devastating sequela. Our study aims to develop a novel blood flow sensor probe to detect changes in OMBF after thoracic stent graft implantation in an experimental swine model. METHODS A novel laser Doppler flowmetry sensor probe incorporating an optical fibre sensor within a nasogastric tube was developed using microelectromechanical system technology. OMBF was measured at various levels using this sensor probe, to test its feasibility before and after thoracic endovascular stent graft implantation covering Th4-Th8 vertebral levels in 6 swine. RESULTS In the middle oesophagus (Th5-Th7), where the aorta was covered with a stent graft, the measured OMBFs were significantly decreased after thoracic endovascular stent graft implantation than those of baseline (8.6 ± 2.7 vs 18.4 ± 7.9 ml/min/100 g, P < 0.0001), followed by a plateau period for at least 2 h after stent grafting (8.7 ± 3.3 ml/min/100 g, P < 0.0001 vs baseline). OMBFs in the upper (Th1-Th3) and lower (Th9-Th11) oesophagus, where the aorta was not covered with a stent graft, were unaffected by thoracic endovascular stent grafting. CONCLUSIONS The novel laser Doppler flowmetry sensor probe was useful to monitor precise changes of OMBF in a swine model, demonstrating a significant reduction in OMBF after thoracic endovascular stent graft implantation.

Native aortic valve thrombosis in patient with protein S deficiency

A 45-year old man was referred to our hospital because of a fever. His blood culture revealed a Streptococcus pneumoniae infection; ultrasound cardiography recorded vegetation at the aortic valve. Infective endocarditis was diagnosed, and antibiotic therapy was initiated. Although the infection and heart failure were controlled, at approximately two weeks after the antibiotic therapy initiation, a seconddegree atrioventricular block was observed. Transesophageal echocardiography revealed an annular abscess extending to the non-coronary cusp annulus (Picture 1, 2) that also communicated with the left atrium (Picture 3). We performed abscess debridement, annulus and defect reconstruction with a bovine pericardium patch, and aortic valve replacement using a mechanical valve. The patient recovered without any recurrent infective endocarditis or heart failure symptoms. Even today, annular abscesses are serious complications of infective endocarditis (1). It is important to select an appropriate treatment strategy, including surgical planning, in order to precisely diagnose the existence and extension of the abscess preoperatively.

Adventitial Cystic Disease Communicating with the Knee Joint: A Case Report with Histopathological Study of the Connection

Native aortic valve thrombosis is an extremely rare condition, the causes of which include previous aortic valve diseases, endocarditis, valvular injury by a catheter intervention and an underlying hypercoagulative state. Its diagnosis is important for preventing life-threatening embolic complications. Here, we report a case of native aortic valve thrombosis and recurrent systemic embolism in a patient with protein S deficiency, a disorder associated with a hypercoagulative state.

Contraction support for the right ventricle by a shape memory alloy fibered artificial myocardium

Adventitial cystic disease is a rare nonatheromatous cause of popliteal artery disease. Here, we present a case of a 51-year-old male patient who presented with right calf claudication caused by adventitial cystic disease. Preoperative magnetic resonance imaging and intraoperative findings revealed the presence of a connection between the cyst and adjacent knee joint. In addition, histopathological examination revealed that the tissue structure of the connection was similar to that of adventitial cysts. The tissue composed of 2 types of cells, namely macrophages and fibroblast-like cells, and lesional cells expressed D2-40. These findings supported the ganglion theory as the underlying physiopathology of this disease and were helpful in deciding the management of this case.

A novel biodegradable external mesh stent improved long-term patency of vein grafts by inhibiting intimal–medial hyperplasia in an experimental canine model

Mechanical cardiac support by using artificial organs improves the circulatory condition in the patients with heart failure. However, the thrombotic and bleeding complications might be caused by the use of these artificial prosthetic internal organs because of their direct attachment with blood. We have been developing an implantable artificial myocardial assist device that can support the natural ventricular contraction from outside of the heart. A shape memory alloy fiber was employed for the implantable design of the myocardial assistance. In this study, we focused on the right ventricular assist by the artificial myocardium using shape memory alloy fibers. We fabricated a prototype of the right ventricular contraction support based on the hinge mechanism design with shape memory fibered actuators. Fundamental characteristics of the contractile effects of the design, as well as its deformation, were examined, and the hemodynamic changes were investigated in the acute animal experiments. As a result, the supporting depth from the ventricular wall increased to be 35 mm, and the volumetric assistance showed around 50 mL incremental assist by the changes in the displacement of the actuator.