Search

Bartonella henselae is well known as a causative organism of cat scratch disease. Although this bacterium infrequently involves the heart, the diagnosis is difficult to confirm. A 75-year-old woman who had a pet cat presented with pancytopenia, hepatosplenomegaly, and low-grade fever. Echocardiography depicted sessile nodules on the aortic valve. C-reactive protein concentration was low, and leukocytosis was not seen. Two sets of blood culture turned out negative. However, elevated B. henselae immunoglobulin G titer led us to the diagnosis of infective endocarditis. Minocycline was administered orally in combination with intravenous administration of gentamicin as an antimicrobial treatment. The patient underwent aortic valve replacement 2 months after her initial visit. Warthin–Starry silver staining did not show any bacterial bodies. The culture of the vegetation tissue was negative. Polymerase chain reaction testing of the excised valve tissue detected the deoxyribonucleic acid of the organism. The postoperative course was uneventful, and the patient was discharged home.

A bipolar radiofrequency clamp is an attractive alternative to the cut-and-sew technique for surgical ablation of atrial fibrillation. We have been using this device for isolating the posterior left atrium. However, there is a risk of disconnection of the ablation lines as well as perforation of the left atrium by the tip of the radiofrequency clamp. Here, we report our simple contrivance to make the procedure more secure and safe.

The long-term benefits of "free" gastroepiploic artery (GEA) grafts remain unclear. The aim of this study is to investigate the long-term patency and clinical results of en bloc free GEA grafts.Of the 1478 patients undergoing coronary artery bypass graft surgery at our institution between January 1997 and December 2009, 137 patients underwent en bloc free GEA grafting. Graft patency, late survival, and freedom from major adverse cardiovascular events were examined. Propensity score matching was used to compare the patency of free GEA grafts with the saphenous vein grafts, and 134 matched pairs were generated.The early patency rate of free GEA grafts was 98.6%. The long-term patency rates of the free GEA grafts was 96.5% at 5 years, 95% at 10 years, and 86.6% at 15 years. In the 134 matched pairs, the long-term patency rates of free GEA grafts anastomosed to the right coronary artery were significantly higher than those of saphenous vein grafts to the right coronary artery (97% vs 91.8% at 5 years; 95.3% vs 79.6% at 10 years; 85.9% vs 61.7% at 15 years; P.001). Survival was 94% at 5 years, 86.6% at 10 years, and 66.8% at 15 years; and freedom from major adverse cardiovascular events was 93.2% at 5 years, 91.3% at 10 years, and 73.1% at 15 years.En bloc free GEA grafts had favorable long-term performance and can be considered as an effective option for patients who need to receive as many arterial grafts as possible.

In conventional tricuspid valve replacement, there is a risk of valve detachment because stitches are placed on relatively fragile tissues. In the supra-annular implantation technique, stitches are placed lateral to the triangle of Koch and the coronary sinus instead of the anterior and septal leaflets as in conventional tricuspid valve replacement. This procedure relieves stress at the antero-septal commissural area, as well as avoids injury to the conduction system. However, there are a few drawbacks: (1) the valve sits obliquely at the annular surface, (2) the suture line becomes extremely long, and (3) the venous return to the coronary sinus may be impeded. We modified the suture line, which travels lateral to the triangle of Koch and medial to the coronary sinus, to solve these problems. We herein report the technique and results of four cases. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s12055-019-00905-z) contains supplementary material, which is available to authorized users.

Objective Surgical site infection (SSI), particularly deep sternal wound infection (DSWI), is a serious complication after cardiovascular surgery because of its high mortality rate. We evaluated the effectiveness of an SSI bundle to reduce DSWI and identify the risk factors for DSWI. Methods During the period January 2004 to February 2012, 1374 consecutive patients undergoing cardiovascular surgery via sternotomy were included. The cohort was separated into periods from January 2004 through February 2007 (period I, 682 patients) and March 2007 through February 2012 (period II, 692 patients). During period II, all preventive measures for DSWI were completed as an SSI bundle. We compared the DSWI rate between the 2 periods. Univariate and multivariate analyses were performed for the entire period to identify the risk factors for DSWI. Results DSWI occurred in 13 patients (1.9%) during period I and in 1 patient (0.14%) during period II. The DSWI rate during period II was significantly decreased by 93%, compared with period I ( P = .001). Independent risk factors for DSWI included obesity (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.00-11.75; P = .049), the use of 4 sternal wires (OR, 8.2; 95% CI, 1.39-48.14; P = .020), long operative time (OR, 4.4; 95% CI, 1.20-16.23; P = .026), and postoperative renal failure (OR, 9.0; 95% CI, 2.44-33.30; P = .001). Conclusions Complete implementation of simple multidisciplinary prevention measures as a bundle can greatly decrease the incidence of DSWI.

Background The efficacy of retrograde cardioplegia for myocardial protection is still controversial. In our institution, we exclusively use intermittent administration of tepid, undiluted blood supplemented with potassium and magnesium for the cases with aortic insufficiency, requiring aortotomy, or undergoing mitral valve repair. In using this retrograde technique, we make a point of cannulating a retrograde perfusion catheter under direct vision following right atriotomy. The purpose of this retrospective study is to evaluate the clinical outcome of using this technique. Methods This study comprises 49 patients who underwent elective valve surgery using direct-vision retrograde cardioplegia exclusively, requiring more than 3 h aortic cross-clamping. Their clinical outcome was reviewed retrospectively. Results There was no hospital mortality in this study. No patient was noted to have evidence of mediastinitis, myocardial infarction, or cerebral complications in the postoperative period. The case requiring the longest aortic cross-clamping time (380 min) survived the operation without the use of intra-aortic balloon pumping or percutaneous cardiopulmonary support, and the postoperative course was uneventful. Conclusions Our result suggests that direct-vision retrograde cardioplegia is a safe and effective method of cardioplegia delivery, and provides a longer period of myocardial protection than previously thought.

Saphenous vein graft aneurysms are rare but are potentially fatal and their optimal management is not clearly established. Herein, we report a case of a saphenous vein graft aneurysm that was successfully treated with surgical intervention, including aneurysmal resection and re-grafting. The aneurysm, detected 36 years after coronary artery bypass grafting, was located at the proximal part of the saphenous vein graft to the posterolateral branch; the flow of the left anterior descending coronary artery was limited due to compression of the left internal thoracic artery by the adjacent aneurysm. The proximal anastomotic site was reconstructed under deep hypothermic circulatory arrest using a radial artery graft pre-sewn vascular prosthesis patch.

Background Use of the free gastroepiploic artery (GEA) graft for coronary revascularization is not very popular because of its tendency to vasospasm. We hypothesize that the cause of free GEA spasm is graft damage caused by an interruption of venous drainage from the graft. To overcome this problem, we anastomosed the accompanied gastroepiploic vein to the right atrial appendage simultaneously with the GEA grafting in the aortocoronary position. We here assess the clinical result and the angiographic patency of the free GEA graft in our method in the late postoperative period. Methods Between January 1997 and April 2001, 57 patients underwent coronary artery grafting with a free GEA using our method. A total of 169 distal anastomoses (average 2.96) were constructed. The free GEA grafts were anastomosed to the main right coronary artery in 26 patients, right coronary artery branch in 27, left anterior descending artery in 1 patient, high lateral branch in 2 patients, and circumflex branch in 2. The mean clinical follow-up is 77 months (range, 35 to 110) in 57 cases, and the angiographic follow-up averages 77 months (range, 37 to 110) in 46 cases. Results There was no cardiac death, and all patients were in Canadian Cardiovascular Society class II or less. The mean 77-month patency rate of the free GEA in our method was 95.7%. The patency rates of internal thoracic artery, radial artery, and saphenous vein graft in the same period were respectively 93.2%, 100%, and 81.3%. Conclusions Free GEA grafting with venous drainage for myocardial revascularization provided excellent long-term performance.

This paper describes the results on thermal and chemical analysis of polytetrafluoroethylene (PTFE) film stack after high-energy heavy ion beam irradiation under atmospheric fields at room temperature. After high-energy C6+ ion beam irradiation, the PTFE film stack was separated one by one, and then the various measurements such as differential scanning calorimetric (DSC) analysis and solid-state 19F magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy were performed to get information of the chemical reaction and structural change at the localized positions. By ion beam irradiation for PTFE at room temperature, it is suggested that the abnormal phenomena due to the change of morphology could be observed by DSC analysis. In the solid-state 19F-MAS-NMR spectroscopy of ion irradiated PTFE film including Bragg peak region, several new signals were observed besides the intense peak of –CF2– at −124 ppm. The detected new signals in ion irradiated PTFE should be due to the changed chemical structures. The signals, which are assigned, to the tertiary carbon group with branching site (Y-type crosslinking site), perfluoro-propylene site and chain end methyl site were directly detected, though it was under the oxidation condition. Thus, although it was under the oxidation condition, the branching or crosslinking reaction was taken place with the chain scission in the matrix. Moreover, the branched chain length would become short, compared with EB-crosslinked PTFE. Hence, it could be suggested that the irradiation of heavy ion beam induced large amounts of intermediate species, compared with EB or γ-ray irradiation, and then, those would be reacted with each other in the localized area. Especially, in region of the Bragg peak, the ion beam induced more large amounts of intermediate species than in the other region.

Poly (tetrafluoroethylene-co-perfluoroalkylvinylether) (PFA) was irradiated by soft electron beam (soft-EB) under nitrogen gas atmosphere in solid-state and its molten state, respectively. The changes of thermal property and chemical structures of irradiated PFA in solid-state and molten state were studied by differential scanning calorimetric analysis (DSC) and solid-state 19 F magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. By DSC analysis, the melting temperature shifted to lower temperatures, and crystallinity decreased with increasing soft-EB dose. By solid-state 19 F MAS NMR spectroscopy, the new signals was observed and the detected new signals in irradiated PFA at 315 °C and at 30 °C were due to the tertiary carbon group with branching site (Y-type crosslinking site), perfluoro-propylene site and chain end methylene groups, respectively. Moreover, the molar ratio of perfluoroalkylvinylether (FAVE) structure to –CF 2 – units decreased with increasing dose.

Polymer electrolyte fuel cell (PEFC) membranes based on thin film of crosslinked perfluorinated polymer-alloys (RX-FA) have been fabricated by soft electron beam (soft-EB) grafting with styrene monomers using soft-EB irradiation under nitrogen atmosphere at room temperature (RT). The characteristic properties of styrene-grafted materials (GRX-FA) and sulfonated materials (SRX-FA) have been measured by differential scanning calorimetry (DSC) and FT-IR spectroscopy, ionic conductivity and so on. The glass transition temperatures (dry state) of all obtained SRX-FA were about 105 ± 1 °C, which are higher than Nafion®. The ion exchange capacities of SRX-FA have been achieved about 3.3 meq/g (dry). The ionic conductivity of obtained SRX-FA has showed about 0.17 S/cm at 60 °C with relative humidity (RH) of ∼95%. The ionic conductivities of the obtained SRX-FA were higher than that of conventional perfluoro-sulfonic acid membranes (PFSA). Fabricated membrane electrode assemblies (MEAs) based on the obtained SRX-FA have shown encouraging performance in the PEFC, compared with the conventional PFSA. The power density of obtained MEAs based on the SRX-FA was about 330–340 mW/cm2 under 500 mA/cm2 at 60 °C operation. Moreover, the maximum power densities of obtained MEAs based on the SRX-FA shows about 630 mW/cm2 at 60 °C. On the other hand, the power density at 500 mA/cm2 and maximum power density of MEA based on Nafion®112 were about 320 and 590 mW/cm2 at 60 °C. Thus, the power density of the obtained SRX-FA was higher than that of conventional PFSA.

The performance of polymer electrolyte fuel cell (PEFC) is affected by an interfacial property between a proton exchange membrane (PEM) and electrodes. Thus, to develop a well-laminated membrane electrode assembly (MEA), a hybrid PEM (FN) was fabricated by mixing a radiation grafted membrane (sulfonated FEP) with ionomer (Nafion® dispersion) which is applied to coat the interface of the PEM and electrodes. The obtained FN, sulfonated FEP and Nafion®112 were characterized in terms of water uptake, ion exchange capacity (IEC), polarization performance and electrochemical impedance. FN showed high IEC and water uptake, which would induce the highest ionic conductivity (IC) among tested PEMs. In terms of FN, the interface between the PEM and electrodes should have been improved because FN showed the lowest charge transfer resistance than other tested PEMs. The high IC and improved interface between the PEM and electrodes resulted in the best cell performance of FN in tested PEMs.

It remains unclear how cardioplegic arrest affects surgical results after coronary artery bypass grafting surgery (CABG). This study compares early outcomes after on-pump beating-heart CABG and conventional CABG.From 2002 to 2005, 114 patients underwent on-pump beating-heart CABG. Multivariate logistic regression revealed five characteristics according to which technique is liable to be used: history of cerebral infarction, urgent or emergent operation, lower ejection fraction, preoperative creatine kinase, and lower number of diseased vessels. The early clinical outcome for these patients was compared against 114 conventional CABG patients, matched using a propensity score constructed with these five significant variables and with two nonsignificant variables: history of diabetes mellitus and hypertension.On-pump beating-heart CABG significantly reduced the duration of operation and cardiopulmonary bypass, total blood loss, and peak creatine kinase (p0.05). The number of patients requiring additional intra-aortic balloon pump support was significantly lower in the on-pump beating-heart CABG group (2 versus 13, p0.01). No patients required percutaneous cardiopulmonary support after on-pump beating-heart CABG, whereas 4 patients needed it after conventional CABG. Complete revascularization was significantly lower (42.1% versus 77.2%, p0.0001), but in-hospital mortality was less in the on-pump beating-heart CABG group (2.6% versus 9.6%, p0.05). No significant difference was found in morbidity including stroke, renal failure, mediastinitis, and prolonged ventilation.On-pump beating-heart CABG can be performed safely, including on high-risk patients. Use of cardiopulmonary bypass and the elimination of cardioplegic arrest may be of most benefit to hemodynamically unstable patients.

Polymer electrolyte fuel cell (PEFC) membranes based on crosslinked tetrafluoroethylene-co-hexafluoropropylene (FEP) have been fabricated by pre-irradiation grafting method. The chemical structures of crosslinked materials have been analyzed by Differential Scanning Calorimeter (DSC) and 19F solid-state Nuclear Magnetic Resonance (NMR) spectroscopy. The radical yields of irradiated samples were measued by Electron Spin Resonance (ESR), and the mechanism of grafting reaction has been discussed. The styrene grafted materials were sulfonated by chlorosulfonic acid. The ion exchange capacity of the obtained sulfonated crosslinked FEP (S-FEP-X) showed 2.0 to 2.4 meq/g, which were 2.2 to 2.7 times higher than that of Nafion®112. Glass transition temperatures (Tg) of S-FEP-X were almost independent on crosslinking dose of FEP, and show about 96 °C, which are slightly higher than that of Nafion®. The electrochemical properties of the membranes have been measured, and cell performances of them have been evaluated. Ionic conductivities (ICs) of S-FEP-X are 1.2 to 1.6 times higher than that of Nafion®. The higher network densities gave the higher open circuit voltage (OCV). The power density of S-FEP-600kGy was about 10% higher than that of Nafion® at 500mA/cm2. Thus, the obtained sulfonated membranes can be expected to apply for high efficiency PEFC.

The sulfonated poly (tetrafluoroethylene-co-hexafluoropropylene) (s-FEP) membranes were synthesized by electron beam (EB) induced grafting method and then milled to the powder. The s-FEP/Nafion® blended dispersion (fn) was prepared by mixing s-FEP powder with the Nafion® dispersion. The s-FEP/Nafion® blended membrane (FN) was obtained by casting the fn binder into the membrane. The membrane electrode assemblies (MEAs) were fabricated by using the proton exchange membranes (FN or Nafion® 112) and the Pt/C electrodes coated with the binders (fn or Nafion® dispersion) . The fuel cell performances of the MEAs were examined. The maximum power density of the MEA using FN membrane and fn binder (particle size of s-FEP: 48 ± 17 μm) was about 600 mW cm-2. This was higher performance than any other tested MEAs. It is considered that this is because the compatibility at the membrane-binder interfaces is improved and the thermophysical properties of the PEM and the binder are essentially the same due to basically the same material.

Proton exchange membranes (PEMs) were prepared by pre-irradiation induced grafting of styrene (S) or styrene/divinylbenzene (S/DVB) into the radiation-crosslinked polytetrafluoroethylene (RX-PTFE) films and then sulfonated. The thicknesses of the obtained PEMs were lower than 20 μm and the ion exchange capacity (IEC) values were around 2 meq g−1. The surfaces of the PEMs and carbon electrodes were coated with Nafion® dispersion, and then membrane electrode assembles (MEAs) were prepared by hot-pressing them together. A MEA based on a Nafion® 112 membrane was also prepared under same procedure for comparison. The performances of the MEAs in a single cell were tested under different cell temperatures and humidifications. Electrochemical impedance spectra (EIS) were measured with ac frequencies which ranged from 100 kHz to 1 Hz at a dc density of 0.5 A cm−2. The obtained impedance curves in Nyquist representation were semicircular.

レールの頭部に生じる波状摩耗は車両走行に伴って振動や騒音を引き起こすと言われ, その発生メカニズムの解明はこの分野の重要な研究課題とされている. 本研究では, 急曲線を走行する鉄道車両を対象として, 車輪と曲線内軌側のレール間に現れる動的現象を, 複雑な車両モデルによるシミュレーション法と簡便な車輪モデルによる解析法とを用いて調べた. その結果, 先頭車輪に生じるアタック角とレール頭頂面の微小な凹凸が原因となって, 車輪とレール間に粘着・すべりの周期的繰り返し運動が生じ, レールの小返り振動が増大する一方, 特定な波長を持った波状摩耗がレール頭頂面に成長することが明らかになった. また, 幾つかの代表的パラメータの組み合わせによる波状摩耗の成長条件と成長過程を大域的に示し, レールの波状摩耗発生メカニズムに関するいくつかの基礎的な知見を得た.

Various types of assist devices have been developed for severe heart failures. Among them, intra-aortic balloon pumping (IABP) has achieved popularity, mainly in the treatment of patients with either severe cardiac infarction or low cardiac output syndrome (LOS) after open-heart surgery. However, IABP has a limitation in that although it acts as a pressure support, it cannot directly support flow volume. In cases of severe pump failure, stronger pump support would be required. However, there is a limit in the clinical use of temporary mechanical support using a pump because of the costs of the expensive equipment. With this in mind, we came up with a new idea in which the motion of a balloon in IABP system is converted into a power source for creating a one-way stream. In order to realize our idea, we made a J-shaped sample model of pulsating chamber incorporating two ball valves. In the hydrodynamic experiment using our new device, flows over 2500 ml/min (Max. 3475 ml/min) were obtained. The percent changes in parameters such as TTI, DPTI and bypass flows obtained by the experiment of left ventricular bypass have demonstrated that our assist system is effective for reducing cardiac work.

急曲線部を走行する鉄道車両においては, 車輪に大きな横圧が作用し, 出口側の緩和曲線部では軌道の平面のねじれも加わり, 外軌側の車輪のフランジはレールに乗り上がり易くなる. 本研究では, このような場合を想定し, 急曲線を低速で通過する車両の走行安全性を検討することを目的とした数値解析シミュレーション法の開発を行い, 主要なパラメータが車輪のレールへの乗り上がりに対してどのような影響を与えるかを二三の解析例で示した. その結果曲線に沿った車両の回転運動による左右レールの相対移動速度差を解析上無視することはできないこと, 低速走行時に静止輪重のアンバランスが大きな値に保持され, さらに車輪・レール間の摩擦係数がある大きな値に達する場合は, 車輪がレールに完全に乗り上がり, 脱輪に至ること等が明らかになった.

This paper lists the genotype frequencies of 50 polymorphisms of 37 genes(ALDH2, ADRB2, ADRB3, COMT, CD36, CXCR2, CCND1, COX2, CYP2A6, CYP17, CYP19, IGF1, IL-1A, IL-1B, IL1RN, IL-1R1, IL-6, IL-8, IL-10, LEP, Le, L-myc, MPO, MTR, MTHFR, MAO-A, NQO1, OGG1, p53, p73, Se, SRD5A2, TGF-B, TNF-A, TNF-B, XPD, and XRCC1)and 6 sets of combined genotype frequencies for 241 non-cancer Japanese outpatients.Though the genotype frequencies of 25 polymorphisms have already been reported in our previous papers, 15 polymorphisms(CD36 A52C, CXCR2 C785T, CCND1 G870A, IGF1 C/T at intron 2 and G2502T, IL-1A 46-bp VNTR, IL1R1 C-1 16T, IL-6 Ins/Del 17C, IL-8 A-278T and C74T, IL10 T-819C, LEP A-2548G, SRD5A2 2bp VNTR, XPD Lys751GIn, and XRCC1 Arg399Gln)and six sets of combined genotype frequencies(IL-1B C-31T and IL-1A C-889T, IL-1B C-31T and IL-1RN 86-bp VNTR, IL-1B C-31T and IL-1R1 C-1 16T, TNF-A G-308A and TNF-B A252G, SRD5A2 Val89Leu and 2-bp VNTR, and XRCC1 Arg399Gln and XPD Lys751Gln)were reported in this paper for the first time for Japanese.Although microarray technology will produce this kind of information in near future, this is the first document that reports the genotype/allele frequencies among Japanese for an archival purpose.J Epidemiol, 2002;12:229-236

We performed descending thoracic aortic repair via posterolateral thoracotomy using retrograde cerebral perfusion with direct cannulation into the left internal jugular vein. No postoperative neurological dysfunction was observed. This patient was discharged without any adverse events.

A 66-year-old woman presented with cardiac tamponade. Pericardiocentesis revealed purulent pericarditis. Enhanced computed tomography showed a saccular aneurysm of the aortic arch. An irregularly shaped and partially enhanced mass was seen adjacent to the aneurysm, which suggested development of a mycotic pseudoaneurysm. Surgical drainage was performed through a subxiphoid incision, and continuous irrigation was commenced. On the following day, however, massive bleeding was recognized through the drains. The patient was immediately transferred to the operating theater, and extracorporeal circulation was established. A perforation 1 cm in diameter was found on the anterior surface of the pulmonary trunk, and a large amount of pus came out from the tear. The ascending aorta and the arch were found to be infected. Surgical repair was impossible due to extensive infection, and the patient died. Methicillin-resistant Staphylococcus aureus was isolated from the pericardial effusion, blood, and intraluminal thrombus of the aortic aneurysm.

A 51-year-old man who had been suffering from depression stabbed himself in the chest with an ice pick. At presentation, an ice pick lodged in the left fifth intercostal space was moving synchronously with his heartbeat. Echocardiography revealed that the tip was penetrating the anterior wall of the right ventricle. Because the patient was tamponading, an emergency operation was carried out. The ice pick was removed following the establishment of a cardiopulmonary bypass and pericardiotomy. The perforation of the right ventricle was closed with a pledget-reinforced mattress stitch. On postoperative day 12, a holosystolic murmur was detected on auscultation. Transthoracic echocardiography revealed a ventricular septal defect 5 mm in diameter located near the apex. The pulmonary-tosystemic flow ratio was 1.1 by echocardiographic measurement. No sign of heart failure was present. Although it was agreed to manage the ventricular septal defect conservatively, careful echocardiographic follow-up is mandatory.

A practical simulation method for analysing direct derailment limit of running vehicle for high speed train on oscillating track under an earthquake using a 3 dimensional one vehicle model was proposed. In this method, the Kalker's simple theory and a newly introduced 2 point contact algorithm were applied to estimation of wheel/rail contact force. These application carried a possibility of direct derailment estimation which differed from previous indirect derailment estimation. It was clarified that the jumping derailment occurred at lower lateral frequency of track oscillation but the mounting derailment did at higher frequency and that the derailment limit of track amplitude showed larger value than that of indirect previous method.

Objective Our experience with omental flap transposition in the treatment of deep sternal wound infections is reviewed here with an emphasis on efficacy, risk factors for in-hospital mortality rates, and long-term results. Summary Background Data Even with improvements in muscle and omental flap transposition, the timing of closure and the surgical strategy are controversial. Methods Forty-four consecutive patients with deep sternal wound infections were treated using the omental flap transposition from 1985 through 1994. The strategies included debridement with delayed omental flap transposition or single-stage management, which consisted of debridement of the sternal wound and omental flap transposition. Methicillin-resistant Staphylococcus aureus was cultured from more than 50% of the wounds. A logistic regression analysis was used to identify the predictors of in-hospital death after omental flap transposition. Results There were seven (16%) in-hospital deaths. Univariate analysis demonstrated that hemodialysis and ventilatory support at the time of omental flap transposition were significantly associated with in-hospital mortality rates (p = 0.0023 and p = 0.0075, respectively). Thirty-seven patients whose wounds healed well were discharged from the hospital. Two patients with cultures positive for methicillin-resistant Staphylococcus aureus had recurrent sternal infections. Patients without positive methicillin-resistant Staphylococcus aureus cultures had good long-term results after reconstructive surgery. Conclusions Transposition of an omental flap is a reliable option in the treatment of deep sternal wound infections, unless the patients require ventilatory support or hemodialysis at the time of transposition.

Management of the small aortic root is a significant problem for the surgeon with regard to operative technique and selection of the prosthesis. We report on four adults with a small aortic root who underwent aortic valve replacement with a 16-mm CarboMedics bileaflet valve. All patients now lead normal lives. Postoperative Doppler measurements demonstrated an acceptable transprosthetic gradient.

超電導磁気浮上式鉄道の構造物に用いる鋼材には, 超電導磁石を搭載した車両が通過する時, 移動する磁界によって鋼材内部に電流が誘起され, 磁気抗力と言われる走行抵抗やエネルギー損失が発生する. そのため, 磁気抗力をある限度内に抑えることが要求されている. 本研究では, 磁気抗力を定量的に評価しその低減対策を確立する目的で, 実験的および解析的な検討を行った. その結果, 有限要素法を利用して低磁性鋼の磁気抗力を近似的に解析する手法を示した. また, 実験および解析により鋼材の磁気抗力の特性について検討し, 設計上考慮すべき低減対策を示した.

Tricuspid regurgitation arising from chest trauma 46 years earlier was successfully corrected by valve reconstruction in a 67-year-old man. As the merits of valve repair are well established, it can be advocated for traumatic tricuspid regurgitation, regardless of the time from the causal injury.

三次元ばね・マス・ダンパ系の車両モデルと三次元有限要素法による線路構造物モデルを用いた鉄道車両と線路構造物の動的相互作用解析法の構築を行った. 本法では, 車輪・レール間の非線形力を考慮し, 車両の蛇行動運動も解析することができる. このような多自由度の解析を効率的に行うために, モード解析法を非線形問題に適用した解析法を用いた. 本報では, これらの定式過程および数値解法を示す.

During myocardial ischemia, neutrophils and platelets exert negative effects on the myocardium. In this study, we used a leukocyte removal filter during cardioplegia, and investigated its effect on myocardial damage during reperfusion by measuring the plasma levels of granulocyte components, platelet components, and cardiac enzymes [creatinine phosphokinase (CK) and creatinine phosphokinase myocardial band (CK-MB)] in 24 patients who underwent cardiopulmonary bypass. The patients were divided into two groups of 12 according to whether or not a filter was placed in the cardioplegic route. Blood samples were drawn directly from the coronary sinus before aortic cross clamping, and at 1, 5, and 15 min after declamping. Group F, which had the filter, showed better cardiac enzyme and lipid peroxidation results than group N, which did not. The results of this study suggest that the application of a filter during cold blood cardioplegia may reduce myocardial damage.

浮上式鉄道の連接方式5両編成列車の車両運動数値解析モデルを用いて, 橋梁や高架橋の設計許容変位を求めた. 構造物に変位を与えたガイドウェイを走行する浮上式鉄道車両の動的応答解析を行い, 乗り心地および走行安全性の観点からその結果を評価し, 浮上式鉄道の構造物を設計する際に必要となる桁の許容たわみ量と許容不同変位量を提案した.

変状対策や近接施工におけるトンネル覆工の力学的な健全度評価法を確立することを目的として, 覆工模型実験及び骨組解析によるシミュレーションを行った. 地盤と覆工の相互作用が表現でき, 3次元実験が簡易に行える実験装置を開発し, これにより種々の比較実験を行った. 本論文では, 各種のパラメータがトンネル覆工の変形挙動に与える影響について述べる.

従来のトンネル工法で施工されたトンネルの覆工は, 施工上の理由から, 天端部の巻厚不足と背面空洞の存在という構造的欠陥を有することが多い. このような欠陥が覆工の力学挙動に与える影響と, 裏込注入工及び鋼板接着・炭素繊維シート接着による内面補強工の効果を模型実験と骨組解析により検討した.

Aneurysms involving either the aortic arch or the proximal descending thoracic aorta in five patients were resected with the aid of profound hypothermic total body retrograde perfusion. Traditional surgical management of the aortic arch and the descending thoracic aorta necessitates clamping of the aorta. However, this technique may be associated with rupture or atheroembolism. Rupture occurring at the clamping site may be difficult to repair. Atheroembolism to the brain compromises the neurologic system, and multiple organ embolism is associated with disseminated intravascular coagulopathy. Atheroembolism in cardiovascular surgery has become increasingly prevalent. It is necessary to prevent clamp injuries and to preserve the function of the vital organs, such as the brain, heart, and liver, during aortic reconstruction. We applied a total body retrograde perfusion technique to operations for aortic aneurysms. Total body retrograde perfusion consists of cerebral protection by continuous perfusion through the superior vena cava, intermittent retrograde coronary perfusion through the coronary sinus, and continuous abdominal visceral perfusion through the inferior vena cava. It can yield a relatively bloodless operating field without the need for aortic clamping. We believe this new adjunct offers excellent results in the surgical treatment of aneurysms of the aortic arch or adjacent structures.

良好な乗心地の確保のため, 浮上式鉄道のガイドウェイは高い精度で施工されなければならない. 本論文では, 単位施工長, 走行速度および車両の振動特性から定まる「乗心地影響係数」を用いてガイドウェイの施工精度とガイドウェイ狂いのパワースペクトル密度および乗心地レベルとの関係を定式化し, ガイドウェイ狂いの特性について言及した. また, この関係式をもとに乗心地レベルを考慮した施工精度の決定方法を提案する.

Adverse effects of cardiopulmonary bypass on cancer prognosis are expected but have not been confirmed. Seventy-four cancer patients who underwent cardiac surgery before cancer therapy were followed up for 42 ± 37 months; 45 had cardiac surgery with cardiopulmonary bypass. There was no significant difference in cancer recurrence (40.0%) and deaths (26.7%) among patients who had cardiopulmonary bypass and those who underwent off-pump cardiac surgery (27.6% and 24.1%). There were no significant differences in freedom from cancer-related death at 2 and 5 years after cardiac surgery (78.4% and 68.5%) in the cardiopulmonary bypass group compared to the 29 off-pump group (81.8% and 58.3%). Despite some limitations, this study detected no significant adverse effects of cardiopulmonary bypass on cancer prognosis. Although these results do not verify the safety of cardiopulmonary bypass from an oncologic aspect, they suggest it can be applied in cancer patients who require cardiac surgery.

For coronary artery bypass grafting, the use of free gastroepiploic artery is unpopular because of its tendency to vasospasm. We assessed the en-bloc free gastroepiploic artery graft, which has the gastroepiploic vein anastomosed to the right atrial appendage to prevent graft spasm, and compared it to the skeletonized free gastroepiploic artery graft. A retrospective review was conducted in 57 patients who received en-bloc grafts and 29 who had skeletonized grafts. Kaplan-Meier analysis demonstrated the superiority of the en-bloc free gastroepiploic artery graft with an 80-month patency rate of 96.6% compared to 66.7% with skeletonized grafts. We selected 13 cases from each group, using propensity-score matching, and compared the long-term patency rates. Propensity-score matched analysis showed 80-month patency rates of 100% for en-bloc grafts and 60% for skeletonized grafts. Coronary artery bypass using free gastroepiploic artery grafts with venous drainage seems to provide good long-term results.

We report a case of 72-year-old man with severe manifestations of coronary artery spasm immediately after aortic valve replacement (AVR), which was associated with hemodynamic and arrhythmic instability. The AVR was performed under mild hypothermic cardiopulmonary bypass (34 degrees C), and retrograde blood cardioplegia was intermittently delivered at the same temperature. Immediately after the operation, the patient suddenly developed severe bradycardia and hypotension, and repeated ventricular fibrillation. Percutaneous cardiopulmonary support system (PCPS) and intra-aortic balloon pumping (IABP) were required for this circulatory collapse. Echocardiography revealed left ventricular segmental dysfunction, and coronary artery bypass grafting (CABG) to the right coronary artery and the left ascending artery was performed [during CABG, coronary spasm was strongly suspected by repetitive ST elevation and depression on electrocardiogram (ECG) monitor]. Eventually, the spasm subsided with the intravenous infusion of nitrates, nicorandil, and diltiazem. The remaining postoperative course was uneventful and the patient was discharged on the 24th postoperative day in good clinical condition.

The use of profound hypothermia and total circulatory arrest in the surgical treatment of aortic dissection has previously been reported. However, the safe period of prolonged circulatory arrest with hypothermia remains controversial. We have developed a technique of hypothermic total body retrograde perfusion to achieve systemic organ protection: cerebral protection by continuous retrograde perfusion through the superior vena cava, myocardial protection by coronary sinus infusion, and abdominal visceral organ perfusion by continuous retrograde perfusion through the inferior vena cava. Our technique yields a relatively bloodless operating field and avoids hypoperfusion of vital organs through a false lumen.

最近9年間に当院および関連施設で手術を行った感染性心内膜炎37例について治療上の問題点につき検討した. 罹患部位は大動脈弁位17例, 僧帽弁位10例, 大動脈弁+僧帽弁10例, 2例は人工弁感染で, 他の35例は自然弁感染であった. 起炎菌は Streptococcus が最も多く20例, Staphylococcus 5例, グラム陰性桿菌3例で10例は培養陰性であった. 術式に大きな影響を及ぼす弁輪部膿瘍は大動脈弁位で10例に認めた. 弁輪の再建は欠損の小さな4例ではマットレス縫合で縫合し, 欠損の広範な4例では自己心膜パッチを縫着し良好な結果を得た. 人工弁付人工血管で translocation を行ったPVEの2例は救命できなかった. 最近は逆行性冠灌流法を採用し顕著な術後LOSの発生をみていない. 術後早期死亡を4例に, 遠隔死亡を3例に認めたが, 感染性動脈瘤破裂による脳出血が2例であり, 今後の検討を要する課題である.

In this paper, a new point to multipoint communication control scheme via satellite characterized by cyclic turn response control based on a receiving station grouping concept is described. Then data transfer experiments are performed to compare the cyclic turn response control scheme (referred to as the proposed response scheme) with the conventional sequential response and simultaneous response schemes, which results in revealing that the proposed response scheme is the most efficient. Furthermore, through considerations of an analytical equation of transmission time, it is qualitatively shown that the proposed response scheme becomes even more effective when the number of receiving stations becomes larger.

The mixed media network including the terrestrial and the satellite communication links is considered, aiming at the realization of a highly reliable information network. This paper proposes a method of physical level switching control in the highspeed multiplexer between the terrestrial and the satellite links. The following three aspects of the physical level switching control method are described. The high-speed digital network management system instructs the link switching to the high-speed multiplexer according to detected faults. The high-speed multiplexer has a function to handle equally the high-speed digital link and the satellite link. The Earth station has the interface function which enables the high-speed multiplexer to switch the master clock. This paper outlines the switching control method at the physical level using the high-speed multiplexer in the transmission network. It discusses also the technical issues as well as their solutions in the implementation, such as the loss of paths for managing information, management of intermittent faults and switching of the master clock. The link switching experiments actually are made between the earth and the satellite in the “pilot study for use of satellite,” underwritten by the Min. Post & Telecomm. The time from the fault detection to the complete link switching in the proposed network management system is within 30 s, indicating the effectiveness of the proposed switching control method.

A case report of difficult sternal closure is described. Chest closure following cardiac operation in critically ill patients can be a problem. Techniques have been described so that sternal closure can be delayed until the patient is hemodynamically stable and hemostasis has been achieved. However, in some instances, the sternal closure can not be performed because of prolonged cardiopulmonary instability. We describe the use of transposition of an omental flap with skin grafting in a 74-year-old patient with aortic valve stenosis, poor pulmonary function, and a thoracic deformity. This technique enabled incomplete sternal closure which maintained hemodynamic stability.

The aim of this study was to evaluate the cause and treatment of atrial flutter after coronary artery bypass grafting (CABG).Between July 1999 and July 2000, 96 CABGs were performed at the Cardiovascular Center of Aichi Prefectural Owari Hospital. We compared two groups of patients: those with atrial flutter after CABG (group A) and those without atrial flutter (group B).We treated the atrial flutter group with medication, electrical defibrillation, and overdrive pacing. Six of these cases later required radiofrequency catheter ablation (RFCA). These were all with common-type atrial flutter, treated by RFCA for the posterior isthmus, without difficulty. The frequency of direct cannulation to the coronary sinus for retrograde cardioplegia was significantly higher in group A.Incidence of atrial flutter after CABG was influenced by surgical damage arising from direct cannulation to the coronary sinus for retrograde cardioplegia. Preoperative viability of the myocardium (in addition to good myocardial protection during surgery) also seems to be associated with an increased likelihood of postoperative atrial flutter.

A 77-year-old woman was admitted to our hospital with transient dysarthria. The patient had atrial fibrillation without a history of valvular disease. Echocardiographic examination showed evidence of a floating mass going and returning between the left atrium and the mitral orifice. With this finding, the cause of the brain embolic episode was found to be due to the thrombus in the heart. Under surgery, a ball thrombus was removed, the size and weight of which were 40x30x25 mm and 15 g, respectively. The patient's postoperative course was uneventful, and she was discharged from the hospital on the 16th postoperative day.

A 56-year-old man admitted with dyspnea had undergone aortic valve replacement using a Starr-Edwards ball valve to treat aortic regurgitation 28 years earlier. Chest radiography showed moderate cardiomegaly, moderate pulmonary edema, and mild pleural effusion. Echocardiographic examination showed severe mitral regurgitation. The mitral valve was replaced using a St. Jude Medical prosthesis, and the Starr-Edwards aortic valve was replaced using a CarboMedics prosthetic valve. The cloth covering on the Starr-Edwards valve had worn away and pannus had formed. The patient's postoperative course was uneventful, and he was discharged on postoperative day 35.