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Dive into the research topics where Shiro Hazama is active.

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Featured researches published by Shiro Hazama.


Journal of Endovascular Therapy | 2003

Chronic Aortic Dissection Complicated by Disseminated Intravascular Coagulation: Successful Treatment with Endovascular Stent-Grafting

Ichiro Sakamoto; Naohiro Matsuyama; Aya Fukushima; Hideyuki Hayashi; Akifumi Nishida; Shiro Hazama; Manabu Noguchi; Kiyoyuki Eishi; Kuniaki Hayashi

PURPOSE To report endovascular repair of a chronic aortic dissection complicated by disseminated intravascular coagulation (DIC). CASE REPORT A 61-year-old man developed DIC associated with a chronic Stanford type B aortic dissection that occurred during cardiac catheterization 12 years earlier. At the current admission, computed tomography showed a partially thrombosed false lumen extending from the aortic arch to the left common iliac artery. On angiography, entry and re-entry tears were identified at the right subclavian and left common iliac arteries, respectively. After stent-graft implantation at the entry and re-entry sites, not only was the false lumen completely thrombosed but the DIC also resolved. The patient is doing well with no complication at 16 months after treatment. CONCLUSIONS Endovascular stent-grafting is an acceptable alternative to surgical repair for aortic dissection accompanied by DIC.


The Japanese Journal of Thoracic and Cardiovascular Surgery | 2000

Successfully treated descending necrotizing mediastinitis through mediansternotomy using a pedicled omental flap

Motoharu Narimatsu; Hisamichi Baba; Shiro Hazama; Manabu Noguchi; Hiroshi Yamaguchi; Katsuo Nishi

A 21-year-old man with an oropharyngeal abscess admitted to our institution was initially treated with systemic antibiotics but was referred to our department when his condition rapidly deteriorated. His respiratory insufficiency required circulatory support. A computed tomographic scan showed a parapharyngeal abscess descending into the mediastinum with multiple right-side capsulized empyema and pericardial effusion. We conducted emergency surgery through a mediansternotomy using a pedicled omental flap. Postoperative clinical and radiologic assessment showed a normal chest X-ray and primary wound healing without sternal dehiscence. Mediansternotomy using a pedicled omental flap offers excellent exposure for a complete one-stage operation with debridement of all affected tissues of the subauricular region, the mediastinum, and both pleural cavities. We conclude that this method yields good results for patients with acute widespread descending necrotizing mediastinitis.


The Japanese Journal of Thoracic and Cardiovascular Surgery | 2011

Systolic anterior motion after mitral valve repair: predicting factors and management

Takashi Miura; Kiyoyuki Eishi; Shiro Yamachika; Kouji Hashizume; Shiro Hazama; Tsuneo Ariyoshi; Shinichiro Taniguchi; Kenta Izumi; Wataru Hashimoto; Tomohiro Odate

PurposeThe aim of this study was to determine the mechanism of systolic anterior motion (SAM) after mitral valve (MV) repair by analyzing the clinical data of patients with MV repair.MethodsA total of 104 MV repairs were performed for patients with isolated degenerative posterior leaflet prolapse. Eight patients (7.7%) developed SAM with severe mitral regurgitation. We compared the preoperative and intraoperative findings of the two groups (8 patients in the SAM group, 96 in the non-SAM group) and reported the clinical courses of the SAM patients.ResultsPreoperative left ventricular end-diastolic and end-systolic diameters were significantly smaller and the preoperative left ventricular ejection fraction was significantly greater in the SAM group than in the non-SAM group. The number of patients with a sigmoid septum and the number with anterior leaflet-septal contact (LSC) during diastole were significantly larger in the SAM group. Incidence of billowing posterior leaflet, prolapsed segments, and operative techniques were comparable for the two groups. SAM improved with correction of hemodynamic status in four patients. In four other patients secondary cardiopulmonary bypass was required to resolve SAM. SAM resolved with additional repairs in two patients, whereas the other two required MV replacement. Of the six patients in whom conservative treatment or re-repair was successful, one had recurrent SAM 3 months after surgery.ConclusionThe sigmoid septum and LSC may predict SAM after MV repair. A strict follow-up is imperative for patients with persistent or recurrent SAM.


Heart and Vessels | 2003

Thrombus removal with a temporary vena caval filter in patients with acute proximal deep vein thrombosis.

Manabu Noguchi; Kiyoyuki Eishi; Ichiro Sakamoto; Satoru Nakamura; Shiro Yamachika; Shiro Hazama; Miyoko Iwamatsu; Yoichi Hisada; Kenta Izumi; Kazuyoshi Tanigawa

Between September 1999 and January 2001 we performed thrombus removal with the use of a temporary vena caval filter in 11 patients who had acute iliofemoral venous thrombosis. To facilitate thrombus removal, 5 patients initially received catheter-directed thrombolytic therapy (thrombolysis group), and the other 6 received surgical thrombectomy (thrombectomy group). Residual thrombus was confirmed after initial catheter-directed thrombolysis in all patients in the thrombolysis group, and thrombolysis was continued in the ward. Bleeding complications subsequently occurred in 2 patients. In the thrombectomy group, 1 patient had residual thrombus just below the temporary filter, and a permanent vena caval filter was deployed for removal. Another patient had a residual thrombus in the superficial femoral vein, and rethrombectomy was performed. One patient in the thrombectomy group died of pneumonia. All other patients were discharged. There were no deaths from pulmonary thromboembolism in this series. Post-thrombotic syndrome occurred in 2 of the 5 patients in the thrombolysis group (40%) and in 3 of the 6 patients (50%) in the thrombectomy group. We conclude that a temporary vena caval filter is useful for the management of acute proximal deep vein thrombosis, especially when aggressive treatment is required.


Heart and Vessels | 2004

Iatrogenic pseudoaneurysm in a hemodialysis patient: the hidden hazard of a high radial artery origin.

Manabu Noguchi; Shiro Hazama; Shyoko Tsukasaki; Kiyoyuki Eishi

High origin of the radial artery is the most common variation in the arterial network of the upper extremities in humans. A 36-year-old Japanese woman undergoing chronic hemodialysis presented with a pseudoaneurysm originating from the brachial portion of the radial artery and associated with a high radial artery origin. Recognition of variants of the arterial network in the upper extremities is crucial for clinicians because their superficial position at the elbow joint may make these vessels vulnerable to injury.


Journal of Endovascular Therapy | 2003

Coil embolization of iliac artery aneurysms developing after abdominal aortic aneurysm repair with a conventional bifurcated graft.

Ichiro Sakamoto; Masakazu Mori; Akifumi Nishida; Aya Fukushima; Eijun Sueyoshi; Shiro Hazama; Kiyoyuki Eishi; Kuniaki Hayashi

PURPOSE To evaluate the efficacy of embolizing iliac artery aneurysms (IAAs) developing after abdominal aortic aneurysm (AAA) repair. METHODS The records of 6 patients (5 men; mean age 79 years, range 61-87) with unilateral (n=3) or bilateral (n=3) IAAs that had developed after AAA repair were reviewed. In all patients, the limbs of the bifurcated graft were anastomosed end-to-end or end-to-side with the external iliac arteries during AAA repair. Before embolization, superior mesenteric artery (SMA) arteriography was done in all patients to evaluate collateral pathways to the inferior mesenteric artery (IMA). RESULTS The unilateral IAAs were treated by proximal and distal embolization. In 2 patients with bilateral IAAs, SMA angiography showed sufficient collateral flow to the IMA, so the aneurysms were treated by proximal embolization and packing. In the other bilateral IAA case, the left 6-cm IAA was treated by proximal and distal embolization, while the contralateral 3-cm IAA was not embolized because angiography demonstrated inadequate collateral flow to the IMA, indicating a possible risk of colon ischemia if both IAAs were embolized. Immediate postprocedural angiography in all patients showed complete exclusion of the IAAs. Mild buttock claudication occurred in 1 patient. There were no episodes of rupture over a mean 46-month follow-up. CONCLUSIONS Embolization is a safe and effective alternative to open surgery for the treatment of IAAs that develop after AAA repair. However, before embolization, angiographic evaluation of collateral pathways to the IMA is essential to reduce the risk of colon ischemia.


Heart and Vessels | 2004

Three cases of ischemic ulcer due to arteriosclerosis obliterans responding to basic fibroblast growth factor spray.

Manabu Noguchi; Kiyoyuki Eishi; Shiro Yamachika; Shiro Hazama

The management of the chronically ischemic leg with ulcer formation that is not suitable for either surgical or interventional treatment is still a matter of controversy. We describe three cases of ischemic ulcer treated with basic fibroblast growth factor spray. Ulcer healing was accelerated and complete epithelialization was achieved in all cases. Basic fibroblast growth factor spray is useful in the treatment of the ischemic ulcer in patients with arteriosclerosis obliterans, especially in high-risk surgical patients.


Journal of Biomedical Optics | 1999

CORRELATION BETWEEN CEREBRAL OXYGEN METABOLISM AND CEREBRAL BLOOD FLOW SIMULTANEOUSLY MEASURED BEFORE AND AFTER ACETAZOLAMIDE ADMINISTRATION

Hiroichiro Yamaguchi; Hideto Yamauchi; Shiro Hazama; Hirotsugu Hamamoto; Nobuhiro Inoue

The cerebral circulation and metabolism of ten preoperative cardiac surgery patients were assessed. Alterations in regional cerebral blood flow (rCBF), measured by 123I-N-isopropyl-p-iodo-amphetamine single-photon emission computed tomography, and in cerebral oxygen metabolism, simultaneously detected by near-infrared spectroscopy (NIRS) before and after acetazolamide administration, were investigated. The rCBF (ml/min/100 g) increased significantly from 40.21±7.65 to 56.24±13.69(p<0.001), and a significant increase in oxyhemoglobin (Oxy-Hb) of 13.9% (p=0.0022) and total hemoglobin (Total-Hb) of 5.7% (0.0047) along with a significant decrease in deoxyhemoglobin (Deoxy-Hb) of 8.9% (p=0.0414) were observed concomitantly. Thus, the Oxy-Hb/Total-Hb ratio (%Oxy-Hb) rose significantly from 67.26±9.82% to 72.98±8.09%(p=0.0022). Examination of the relationships between individual parameters showed that the percentage changes in rCBF and Oxy-Hb were significantly correlated (r=0.758,p=0.011). The percentage changes in rCBF and %Oxy-Hb were also correlated significantly (r=0.740,p=0.014). In conclusion, this evidence suggested that NIRS is able to detect relative changes in cerebral hemodynamics and reflect luxury perfusion induced by acetazolamide.


The Japanese Journal of Thoracic and Cardiovascular Surgery | 2010

Double patch technique for closing acute ventricular septal perforation

Kazuki Hisatomi; Kiyoyuki Eishi; Masayoshi Hamawaki; Koji Hashizume; Shiro Hazama; Tsuneo Ariyoshi; Shinichiro Taniguchi; Takashi Miura; Wataru Hashimoto; Seiji Matsukuma

PurposeVentricular septal perforation (VSP) is a rare but life-threatening complication of acute myocardial infarction (AMI). Even with assisted circulation heart failure often progresses quickly, and urgent surgical intervention is required to close the VSP. For several years, we have been performing a double patch closure technique using an equine pericardial patch. In this report, we present details of our patch closure technique and the VSP surgical results; we also examine the problems we encountered.MethodsThe present study was a review of nine patients who underwent our patch closure of VSP secondary to AMI. We used a large double-layered equine pericardial patch to close the VSP and did not exclude the infarction area from the left ventricular cavity. No necrotic myocardium was excised to avoid simultaneous excision of stunned myocardium.ResultsNo patients died within 30 days of the surgery, and there were no in-hospital deaths. Over a mean clinical follow-up period of 4.5 years, no residual shunts were detected, and all patients were alive and had New York Heart Association functional class II.ConclusionOur patch closure technique was effective for closing VSPs securely. The operating times and cardiopulmonary bypass times were short, and blood loss was minimal. Our patch closure technique may improve the prognosis of VSP.


Journal of Artificial Organs | 2005

Consideration of prosthesis-patient mismatch and left ventricular mass regression after implantation of the Carpentier-Edwards pericardial valve in elderly Japanese patients: body surface area may be irrelevant.

Hideaki Takai; Shiro Yamachika; Shiro Hazama; Tsuneo Ariyoshi; Tomohiro Odate; Seiji Matsukuma; Makoto Yanatori; Daisuke Onohara; Kiyoyuki Eishi

The assessment of prosthesis patient mismatch (PPM) for small aortic annulus is important for prognosis after aortic valve replacement (AVR). Recent investigations have demonstrated that PPM occurs in AVR patients with an indexed effective orifice area (iEOA) of less than 0.85 cm2/m2. We investigated hemodynamic performance and left ventricular mass (LVM) regression after AVR. Eighteen patients who underwent AVR using a 19-mm Carpentier-Edwards pericardial (CEP) valve without annular enlargement were studied by echocardiography and Doppler examination 4 months after AVR. Patients were divided into two groups on the basis of their body surface area (BSA); the smaller BSA (group S, 1.14–1.36 m2, nine patients) and the larger BSA (group L, 1.40–1.83 m2, nine patients). Of these 18 patients, ten underwent isolated AVR, and five underwent AVR with coronary artery bypass graft; (i.e., double valvular replacement, AVR with maze procedure, and AVR with mitral valvulophasty. There were no statistically significant differences between the two groups, except for age (group S, 78.3 ± 2.5 years; group L, 73.6 ± 2.4 years). There was no significant difference for the iEOA during the late phase at rest (group S, 1.10 ± 0.26 cm2; group L, 1.02 ± 0.28 cm2). However, there was a significant difference for the LVM regression between the preoperative and postoperative values (group S, 243 ± 23.6 mg/cm2 [pre], 190 ± 16.9 mg/cm2 [post]; group L, 302 ± 13.7 mg/cm2 [pre], 199 ± 16.7 mg/cm2 [post]). In elderly Japanese patients with a BSA of less than 18 m2, we demonstrated LVM regression and avoidance of PPM after implantation of the aortic 19-mm CEP valve.

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