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Dive into the research topics where Genta Chikazawa is active.

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Featured researches published by Genta Chikazawa.


Journal of Vascular Surgery | 2015

Clinical outcomes of different approaches to aortic arch disease.

Arudo Hiraoka; Genta Chikazawa; Kentaro Tamura; Toshinori Totsugawa; Taichi Sakaguchi; Hidenori Yoshitaka

OBJECTIVE The aim of this study was to evaluate the midterm clinical outcomes of various approaches, including hybrid procedures, to aortic arch pathologies. METHODS Of 305 consecutive patients who underwent aortic arch repair between 2005 and 2013, 244 underwent conventional open total aortic arch repair (CTAR) with antegrade cerebral perfusion under circulatory arrest, 35 underwent debranching of the arch with thoracic endovascular aortic repair (DTEVAR), and 26 underwent staged TEVAR after TAR with elephant trunk (TARET). We retrospectively evaluated the outcomes of the three groups. RESULTS The DTEVAR group had a greater percentage of patients with preoperative comorbidities. Significant differences were observed in 30-day mortality (DTEVAR, 14.3% [5 of 35] vs TARET TEVAR, 0% [0 of 26] vs CTAR, 5.3% [13 of 244]; P = .045) and stroke (DTEVAR, 28.6% [10 of 35] vs TARET TEVAR, 7.7% [2 of 26] vs CTAR, 8.2% [20 of 244]; P = .001). In overall midterm survival, the DTEVAR group had a lower survival rate (63.9% 3-year survival) compared with the CTAR (90.1% 7-year survival) and the TARET TEVAR (95.5% 2.5-year survival) groups. In elective cases, better midterm results were observed in CTAR and TARET TEVAR groups. An increased number of debranching graft and emergency operations resulted in a much lower follow-up survival rate in the DTEVAR group. Atherosclerotic disease had a great effect on midterm outcomes in the DTEVAR (P = .045) and CTAR groups (P = .002). CONCLUSIONS The clinical feasibility of DTEVAR for high-risk patients requiring zone 0 landing or emergency surgery is still controversial. Atherosclerotic disease of the aorta has a significant negative effect on midterm outcomes in any surgical approach.


The Journal of Thoracic and Cardiovascular Surgery | 2010

The Graft Imaging to Improve Patency (GRIIP) clinical trial results

Steve K. Singh; Nimesh D. Desai; Genta Chikazawa; Hiroshi Tsuneyoshi; Jessica Vincent; Brandon Zagorski; Visal Pen; Fuad Moussa; Gideon Cohen; George T. Christakis; Stephen E. Fremes

OBJECTIVE This trial aimed to determine whether intraoperative graft assessment with criteria for graft revision would decrease the proportion of patients with 1 or more graft occlusions or stenoses or major adverse cardiac events 1 year after coronary artery bypass grafting. METHODS A single-center, randomized, single-blinded, controlled clinical trial was designed. Patients were randomized to either of 2 groups: intraoperative graft patency assessment using indocyanine-green fluorescent angiography and transit-time flowmetry, with graft revision according to a priori criteria (imaging group), or standard intraoperative management (control group). Patients underwent follow-up angiography at 1 year. RESULTS Between September 2005 and August 2008, 156 patients undergoing isolated coronary bypass grafting were enrolled (imaging, n = 78; control, n = 78). Demographic and angiographic characteristics were similar between groups. Operative, crossclamp, and cardiopulmonary bypass times were all nonsignificantly longer in the imaging arm. The number of grafts per patients was similar (imaging, 3.0 +/- 0.7; control, 3.0 +/- 0.7). The frequency of major adverse cardiac events (death, myocardial infarction, repeat revascularization) was not different between groups at 1 year postoperatively (imaging, 7.7%; control, 7.7%). One-year angiography was performed in 107 patients (imaging, 55 patients/160 grafts; control, 52 patients/152 grafts). The proportion of patients with 1 graft occlusion or more was comparable in the imaging (30.9%) and control (28.9%) groups (relative risk [95% confidence interval], 1.1 [0.6-1.9]; P = .82), as were other graft patency end points. The incidence of saphenous vein graft occlusion was high in both groups. CONCLUSIONS Routine intraoperative graft assessment is safe but does not lead to a marked reduction in graft occlusion 1-year after bypass grafting. The incidence of saphenous vein graft failure remains high despite contemporary practice and routine intraoperative graft surveillance.


European Journal of Cardio-Thoracic Surgery | 2016

Re-expansion pulmonary oedema after minimally invasive cardiac surgery with right mini-thoracotomy

Yusuke Irisawa; Arudo Hiraoka; Toshinori Totsugawa; Genta Chikazawa; Kosuke Nakajima; Kentaro Tamura; Hidenori Yoshitaka; Taichi Sakaguchi

OBJECTIVES Re-expansion pulmonary oedema (RPO) sometimes occurs after minimally invasive cardiac surgery (MICS) with single-lung ventilation. However, it has not been widely recognized as a serious complication. The aim of this study is to evaluate the occurrence rate and risk factors of RPO. METHODS A total of 381 consecutive patients who underwent MICS with right mini-thoracotomy from March 2005 to October 2013 were retrospectively reviewed. RESULTS RPO was observed in 8 (2.1%) patients. In the preoperative data, greater percentages of preoperative use of steroid or immunosuppressant were found in patients with RPO (25% [2/8] vs 1% [4/373]; P = 0.0056). In the operative data, significantly longer operation, cardiopulmonary bypass (CPB) and aortic cross-clamping (ACC) times as well as greater percentages of second CPB run were found in patients with RPO (388 ± 80 vs 272 ± 61 min; P < 0.0002, 253 ± 79 vs 158 ± 50 min; P = 0.0009, 162 ± 65 vs 108 ± 38 min; P = 0.020 and 38% [3/8] vs 1.3% [5/373]; P < 0.0003). The overall 30-day mortality rate was 0.8% (3/381) and the 30-day mortality rate of patients with RPO was 12.5% (1/8). Significantly prolonged initial ventilation time, intensive care unit and postoperative hospital stay were observed in patients with RPO (P = 0.0022, <0.0001 and 0.0003, respectively). Multivariate logistic analysis detected preoperative use of steroid or immunosuppressant and prolonged ACC time (≥156 min) as independent risk factors for RPO after MICS (odds ratio [OR]: 87.6 [95% confidence interval, CI: 4.1-2463.8]; P = 0.006 and OR: 36.0 [95% CI: 4.8-731.4]; P < 0.001). CONCLUSIONS RPO should be recognized as one of the most serious complications after MICS with right mini-thoracotomy. More accurate risk factors of prolonged lung malperfusion and steroid use on RPO after MICS should be investigated.


Journal of Cardiac Surgery | 2013

Cut‐Off Values for Transit Time Flowmetry: Are the Revision Criteria Appropriate?

Dai Une; Saswata Deb; Genta Chikazawa; Kamya Kommaraju; Hiroshi Tsuneyoshi; Reena Karkhanis; Steve K. Singh; Jessica Vincent; Hideki Tsubota; Jeri Sever; Fuad Moussa; Gideon Cohen; George T. Christakis; Stephen E. Fremes

Graft Imaging to Improve Patency (GRIIP), a single‐center, randomized blinded clinical trial, reported that intraoperative graft assessment with graft revision according to a priori criteria of transit time flowmetry (TTF) and intraoperative fluorescent angiography did not improve graft patency at one year after coronary artery bypass grafting (CABG) when compared with standard intraoperative management. The objective of this study is to investigate whether other TTF values are more predictive of the saphenous vein graft (SVG) failure and/or clinical outcomes.


Annals of Vascular Diseases | 2014

Influencing Factors for Abdominal Aortic Aneurysm Sac Shrinkage and Enlargement after EVAR: Clinical Reviews before Introduction of Preoperative Coil Embolization

Genta Chikazawa; Arudo Hiraoka; Toshinori Totsugawa; Kentaro Tamura; Atsuhisa Ishida; Taichi Sakaguchi; Hidenori Yoshitaka

BACKGROUND We previously reported effectiveness of coil embolization (CE) to aortic branched vessels before endovascular aortic repair (EVAR) for abdominal aortic aneurysm (AAA) because of significant shrinkage of aneurysmal sac. In this study, we investigated EVAR cases to clarify influential factors of aneurysmal shrinkage and enlargement. METHODS 148 consecutive cases before the introduction of CE were retrospectively reviewed based on the presence of PT2EL (persistent type 2 endoleak) and change in sac diameter after EVAR by multivariate analysis. RESULTS (A) PT2EL risk factors were patent inferior mesenteric artery (IMA) and thinner mural thrombus inside aneurysmal sac. (B) Sac enlargement risk factors were antiplatelet intake, PT2EL, and female gender


Annals of Vascular Diseases | 2013

Preoperative Coil Embolization to Aortic Branched Vessels for Prevention of Aneurysmal Sac Enlargement Following EVAR: Early Clinical Result

Genta Chikazawa; Hidenori Yoshitaka; Arudo Hiraoka; Koyu Tanaka; Norio Mouri; Kentaro Tamura; Toshinori Totsugawa; Atsuhisa Ishida; Taichi Sakaguchi

OBJECTIVE Persistent Type 2 endoleaks (PT2) after endovascular aortic aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) are associated with increased adverse outcomes, including aneurysmal sac enlargement and rupture. The aim of this study was to report early clinical outcomes of coil embolization (CE) to aortic branched vessels prior to EVAR and assess the effectiveness of this strategy in terms of prevention of sac growth due to PT2. MATERIALS AND METHODS Between May 2007 and April 2012, EVAR was performed for 215 cases, divided into two groups (150 cases in Group A, before introduction of CE; 21 in Group B, receiving CE before EVAR). Early clinical outcomes were compared between groups. RESULTS Fifty percent of cases in Group B had a marked reduction of aneurysmal sac diameter based on multi-detector row computed tomographic angiography (MDCTA) findings at the 6-month follow-up after EVAR, whereas, only 25% of cases in Group A had shrinkage of the aneurysmal sac during the same time period after EVAR. CONCLUSION This strategy has the possibility of improving late outcomes of EVAR by reducing endoleak volumes beforehand.


Journal of Physical Therapy Science | 2015

Effect of in-hospital physical activity on cardiovascular prognosis in lower extremity bypass for claudication

Tomohiro Matsuo; Taichi Sakaguchi; Atsuhisa Ishida; Satoshi Yuguchi; Kazuya Saito; Masaharu Nakajima; Takuya Ujikawa; Tomoyuki Morisawa; Genta Chikazawa; Tetsuya Takahashi

[Purpose] This study aimed to evaluate the effect of in-hospital physical activity on patient prognosis after lower extremity bypass surgery for peripheral arterial disease. [Subjects and Methods] A total of 13 patients (16 limbs; 11 males and 2 females; mean age [standard deviation], 72.8 [5.9] years) who underwent lower extremity bypass surgery for Fontaine stage 2 peripheral arterial disease were included in this study and assigned to either an active group (n = 6) to perform increased physical activity after surgery or an inactive group (n = 7) to perform decreased physical activity after surgery. Daily in-hospital physical activity levels were measured continuously with a triaxial accelerometer. The occurrence of adverse cardiovascular events within a 2 year follow-up period was compared between groups. [Results] At discharge, the patients in the active group were able to walk more steps daily than those in the inactive group. The incidence of adverse events was 16.7% in the active group and 71.4% in the inactive group. [Conclusion] A higher in-hospital physical activity level was associated with a better long-term prognosis after lower extremity bypass surgery in patients with peripheral arterial disease.


The Annals of Thoracic Surgery | 2013

Bridge Use of Endovascular Repair and Delayed Open Operation for Infected Aneurysm of Aortic Arch

Kentaro Tamura; Hidenori Yoshitaka; Toshinori Totsugawa; Yoshimasa Tsushima; Genta Chikazawa; Tsukasa Ohno; Taichi Sakaguchi

We present the first clinical report of the successful treatment of an infected thoracic aortic arch aneurysm with the use of endovascular repair as a bridge to second-stage open operation. A 70-year-old patient underwent urgent endovascular repair through the right femoral approach because of a diagnosis of sepsis and impending rupture of an infected thoracic aortic arch aneurysm. After 2 weeks of medical treatment, we successfully performed explantation of the stent graft, wide debridement of the surrounding tissue, and in-situ replacement using a rifampicin-bonded four-branched prosthetic graft with omental flap.


Journal of Cardiothoracic Surgery | 2013

Mitral valve reoperation under ventricular fibrillation through right mini-thoracotomy using three-dimensional videoscope

Arudo Hiraoka; Masahiko Kuinose; Toshinori Totsugawa; Genta Chikazawa; Hidenori Yoshitaka

BackgroundConventional reoperative mitral valve surgery by median sternotomy has several difficulties. We performed mitral valve replacement (MVR) under ventricular fibrillation (VF) through right mini-thoracotomy with three-dimensional videoscope for avoiding the problems.MethodsBetween 2006 and 2011, we performed 257 cases of MVR, in which 125 cases underwent isolated MVR. Ten cases of patients underwent reoperative MVR under VF through thoracotomy with three-dimensional videoscope (Group I), and 27 cases of patients underwent reoperative conventional MVR through median sternotomy (Group II). We retrospectively reviewed the outcomes and compared Group I with Group II. Preoperative left ventricular ejection fraction (LVEF) was significantly lower (50.5 ± 19.8% vs 64.4 ± 12.0%; p = 0.046), and significantly higher Euro SCORE was found in Group I (4.8 ± 2.0 vs 3.8 ± 2.4; p = 0.037).ResultsAlthough Group I required cooling and rewarming time, average operative times was significantly shorter in Group I (262 ± 46 min vs 300 ± 57 min; p = 0.044), and cardiopulmonary bypass times and average VF times in Group I and aortic cross-clamp times in Group II were equivalent. There was no significant difference in the average of postoperative maximum creatine kinase (CK)-MB. In-hospital mortality was 0/10 (0%) and 1/27 (3.7%), and postoperative paravalvular leakage occurred in 0/10 (0%) and 1/27 (3.7%), and stroke occurred in 1/10 (10%) and 1/27 (3.7%) for Groups I and II. Two patients underwent reoperation for bleeding in Group II. Intensive care unit stay in Group I was significantly shorter than in Group II (1.8 ± 0.6 days vs 3.0 ± 1.7 days; p = 0.025).ConclusionsThe higher risk of preoperative background in Group I had no effect on the operation. Mitral valve surgery under VF through right mini-thoracotomy can be an alternative procedure for reoperation after conventional various cardiothoracic surgeries.


The Japanese Journal of Thoracic and Cardiovascular Surgery | 2011

Intraoperative direct hemoperfusion with a polymyxin-B immobilized fiber column for treatment of infective endocarditis

Toshinori Totsugawa; Masahiko Kuinose; Hidenori Yoshitaka; Yoshimasa Tsushima; Atsuhisa Ishida; Genta Chikazawa; Keijiro Katayama; Arudo Hiraoka

PurposeEndotoxin adsorption treatment (direct hemoperfusion using a polymyxin-B immobilized fiber column, or PMX-DHP) is now considered a useful option for treating severe sepsis. However, the efficacy of PMX-DHP for infective endocarditis (IE), in which the causative microorganisms are usually Gram-positive cocci, remains unclear. In the present study, we investigated the impact of intraoperative PMX-DHP on clinical parameters during the treatment of IE.MethodsFrom November 2006 to December 2009, a total of 11 patients with active IE underwent emergent surgery using intraoperative PMX-DHP. The perioperative courses of these patients were compared with those of seven patients who underwent emergent surgery for active IE with the conventional method from January 2003 to October 2006.ResultsPMX-DHP was associated with a significant decrease in the postoperative catecholamine dose and duration. Intubation time and intensive care unit length of stay for the PMX-DHP group was significantly shorter than that for the conventional therapy group. There was also a significant difference in the number of failed organs postoperatively between the two groups.ConclusionIntraoperative PMX-DHP demonstrated several positive effects, such as a drastic decrease in the doses of inotropic agents and shortening of the duration of mechanical ventilation, in patients who underwent emergent surgery for active IE. Intraoperative PMX-DHP can be a useful option for the treatment of critically ill patients with IE.

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Hidenori Yoshitaka

Cardiovascular Institute of the South

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Toshinori Totsugawa

Cardiovascular Institute of the South

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Arudo Hiraoka

University of Pennsylvania

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Yoshimasa Tsushima

Cardiovascular Institute of the South

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Koyu Tanaka

Dokkyo Medical University

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