Publications by authors named "Mitsuhiro Yamamura"

Postoperative intimal hyperplasia is the major cause of the vein graft occlusion. It is very important to establish an animal model for the start of research. After my vascular surgery residency in Japan, I started my research work on postoperative intimal hyperplasia at the University of Wisconsin-Madison.

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Optimal timing of open-heart surgery for the treatment of patients with cerebral hemorrhage remains controversial because systemic heparinization may lead to catastrophic bleeding. Several recent reports have shown that patients who undergo open-heart surgery .within a few weeks of cerebral hemorrhage have a much lower risk of exacerbated bleeding than previously considered.

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In patients with a narrow sinotubular junction, small sinus of Valsalva, or extensibility loss in the aortic root, aortic valve replacement (AVR) with a standard valve is challenging due to limited surgical field. Detailed preoperative measurements of the aortic root render performing AVR using the Perceval valve easy.

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Cardiac perforation is a rare but serious and life-threatening complication of permanent pacemaker implantation, with an incidence of 0.1-6%. Surgery is usually performed through a median sternotomy; however, sternotomy-related morbidity remains a concern.

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Background: This study was aimed to evaluate the outcomes of performing open repair or thoracic endovascular aortic repair for chronic type B dissecting aortic aneurysm.

Methods: From July 2004 to February 2019, 52 patients underwent surgery as open repair (n = 32) or endovascular repair (n = 20) for chronic type B dissecting aortic aneurysm. Replacement of the aorta was limited to the aneurysmal portion with or without reconstructing the visceral arteries or the segmental arteries.

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A 25-year-old man presented with palpitations and subsequently received a diagnosis of a large epicardial cyst (6.8 × 3.8 cm) originating from the left ventricle.

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Article Synopsis
  • A 76-year-old woman was hospitalized for an ascending aortic aneurysm, which caused obstruction in her left ventricular outflow tract and issues with her mitral valve.
  • Echocardiography revealed high flow velocity in the outflow tract, a warped septum, and some mitral valve regurgitation due to these issues.
  • After replacing the ascending aorta with a graft, both the outflow tract obstruction and mitral valve problems were resolved, likely due to the graft alleviating pressure on nearby structures.
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Systolic anterior motion (SAM) of the mitral valve is a well-known complication in mitral valve repair. Because excessive leaflet tissue is an important mechanism, surgical correction is sometimes required to reduce leaflet height or mobility. However, a different approach may be necessary in cases of normal leaflet height.

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Objective: The aim of this study was to compare outcomes of the full maze procedure with left atrial appendage closure (LAAc) as concomitant procedures for atrial fibrillation (AF) in patients undergoing cardiovascular surgery.

Methods: A total of 151 patients (88 men, 62 women) underwent elective AF surgery concomitantly with cardiovascular surgery from April 2005 to December 2019. The mean age at time of operation was 70 years and the mean follow-up period was 5.

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Hypo-attenuated leaflet thickening (HALT) is gaining attention as a relatively common issue after surgical or transcatheter aortic valve replacement (AVR). However, only a few reports have described HALT in sutureless bioprosthesis, which has emerged as a promising tool with excellent hemodynamics and enhanced implantability. We herein report a 75-year-old woman who underwent quintuple coronary artery bypass grafting and sutureless AVR with a Perceval S bioprosthesis (LivaNova PLC, London, UK).

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A 78-year-old woman diagnosed with an infected descending aortic aneurysm underwent graft replacement through a left rib-cross thoracotomy. She developed shock suddenly on the postoperative day 3 owing to cardiac tamponade. We performed emergent surgery and identified a small myocardial laceration in the left ventricular obtuse marginal area and a small perforation on the pericardium.

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Article Synopsis
  • * An 82-year-old woman with severe aortic insufficiency and a prior endoleak underwent successful combined surgery that included a sutureless AVR using the Perceval valve.
  • * Despite her frail condition and high surgical risk, the patient had a smooth recovery, suggesting that sutureless AVR can be a viable option for high-risk elderly patients needing both aortic arch reconstruction and valve surgery.
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Background: Perioperative stroke is a major complication after debranching thoracic endovascular aortic repair (TEVAR), with a reported incidence of 7.0-26.9%.

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Article Synopsis
  • A study evaluated the effectiveness of abdominal duplex ultrasound (DUS) in detecting endoleaks after endovascular aneurysm repair (EVAR) in 286 patients, with 241 receiving follow-up DUS. !* -
  • Endoleaks were found in 31% of patients, divided into enlarged and nonenlarged sac groups, with significant differences in aneurysm size and endoleak characteristics between the two groups. !* -
  • Measurements of endoleak velocity and width are crucial for determining the need for reintervention, with specific cutoff values identified as 83.4 cm/s for velocity and 4.0 mm for width. !*
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Blood glucose management is important for cardiovascular surgery using cardiopulmonary bypass. The usefulness of an artificial pancreas apparatus (STG-55) to control blood glucose in patients undergoing cardiopulmonary bypass was investigated. Subjects comprised 44 patients using the artificial pancreas during cardiopulmonary bypass between June 2016 and March 2017; 55 were initially enrolled, but 11 were excluded because of blood removal failure.

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: We have previously shown that pretreatment with the free radical scavenger edaravone (Radicut, Mitsubishi Tanabe Pharma Co., Japan) mitigated skeletal muscle damage due to ischemia reperfusion. In this study, we sought to validate its use in an experimental model of myonephropathic-metabolic syndrome (MNMS).

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Objective: Mitral annular structure and dynamics after mitral ring annuloplasty using transesophageal echocardiography during the operation have been reported. We evaluated mitral annular structure and dynamics of three different rings in the mid-term period postoperatively.

Methods: Thirty-one patients underwent mitral valve repair for degenerative mitral insufficiency.

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Objective: This study aimed to evaluate the efficacy of the Functional Independence Measure to assess preoperative frailty for elderly patients undergoing surgical aortic valve replacement.

Methods: Eighty-five patients >65 years who survived elective isolated aortic valve replacement from January 2008 to October 2015 were included. The mean age at the operation was 78 ± 6 years old (n = 28 males, n = 57 females).

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Debranching thoracic endovascular aortic repair for aortic arch pathology is an important alternative to total arch replacement. However, the problem of intraoperative stroke due to atherosclerotic changes in the aorta remains. We apply our minimally invasive mini-cardiopulmonary bypass system to prevent intraoperative stroke during the endovascular procedure.

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An 81-year-old woman developed severe hemolytic anemia after aortic valve replacement. The anemia was not caused by paravalvular leakage, as in most cases. Instead, it occurred secondary to left ventricular outflow tract obstruction that had not been seen preoperatively and was induced by afterload reduction following aortic valve replacement.

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We treated a 57-year-old female patient with an atrial tumor that was widely attached to the atrial septum. The tumor was diagnosed as a cystic tumor of the atrioventricular node (CTAVN). This type of tumor is rare, and its antemortem diagnosis is difficult because it is usually asymptomatic.

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The purpose of this study was to evaluate whether edaravone (Radicut(®), Mitsubishi Tanabe Pharma Co., Osaka, Japan) injected at the start of reperfusion can suppress myonephropathic-metabolic syndrome (MNMS). MNMS models were made by clamping the bilateral common femoral arteries for 5 hours.

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Aim: to evaluate the strategy for open heart surgery after renal transplantation performed in a single institution in Japan.

Methods: we reviewed 6 open heart surgeries after renal transplantation in 5 patients, performed between January 1992 and December 2012. The patients were 3 men and 2 women with a mean age of 60 ± 11 years (range 46-68 years).

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It is well known that free radicals cause reperfusion injury following leg ischemia. We showed that the free radical scavenger, edaravone (Radicut, Mitsubishi Tanabe Pharma Co., Osaka, Japan), might suppress reperfusion injury in rat.

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