Hideki Ito

Spin distributions and excitation spectra of optically generated polarons in poly(p-phenylenevinylene) derivatives

Abstract Light-induced electron spin resonance (LESR) measurements have been performed on two dialkoxy derivatives (MEH-PPV and CN-PPV) of poly(p-phenylenevinylene) where cyano groups are attached at the vinylic carbon sites in CN-PPV. The transient response and excitation spectra of the LESR signals indicate that the observed spins are optically generated polarons. A clear reduction of ESR linewidth has been observed in CN-PPV compared with MEH-PPV, providing direct evidence that the polaron spin density resides predominantly on the vinylic carbons. Linewidth analysis based on a theoretical model for the spin distribution yields an extension of the polaron over approximately four phenyl rings.

Hybrid versus open repair of aortic arch aneurysms: comparison of postoperative and mid-term outcomes with a propensity score-matching analysis

OBJECTIVESnOperative strategies for repairing aortic arch aneurysms should be re-evaluated following recent technical advances.nnnMETHODSnOf 364 patients who underwent aortic arch repair between 2002 and 2014, 58 were high-risk subjects who received isolated hybrid arch repair (HAR) via median sternotomy (type I n = 32, type II n = 1 and type III n = 25). During this period, excluding patients with type A dissection or extensive aneurysms, 124 patients received isolated open arch repair via median sternotomy. The patients in the HAR and open arch repair groups were compared. A propensity score-matching analysis was applied to adjust for baseline risk factors.nnnRESULTSnThe patients in the HAR group were older (77 years ± 6 vs 69 ± 9, P < 0.0001), exhibited a greater rate of malignancy (21 vs 4.8%, P = 0.0022) and had higher logistic EuroSCORE values (31 ± 18 vs 20 ± 15, P < 0.0001) than those in the open arch repair group. Following propensity score matching creating 38 matched pairs, the differences in preoperative risk diminished. Operative complications, including the mortality rate (2.6 vs 0%), were similar between the groups. Apart from the lower rates of cardiopulmonary bypass (CPB) and circulatory arrest, there was no apparent superiority of HAR with respect to patient recovery. The mean follow-up duration was 52.5 months, during which the rate of freedom from aortic events in the HAR and open arch repair groups was 79 and 99% at 24 months, respectively (P < 0.0001).nnnCONCLUSIONSnHAR achieves equivalent short-term results to standard open arch repair, with a decreased need for CPB. However, considering the inferior mid-term outcomes of this procedure, its indications should be limited to high-risk patients.

Two-stage operation for isolated pulmonary valve infectious endocarditis with Candida parapsilosis

We report a case of isolated pulmonary infectious endocarditis (IE) with Candida parapsilosis. A 66-year-old man presented with fever and cough. Echocardiography showed severe pulmonary regurgitation and vegetations on the pulmonary valves. Initially, antibiotics were prescribed against bacterial IE, and the vegetations disappeared; however, the pulmonary vegetations relapsed, and C. parapsilosis was grown from blood cultures. We performed a debridement without a pulmonary valve replacement. There was no recurrence of IE for 3 years, and then the patient developed right ventricular enlargement and severe tricuspid regurgitation due to severe pulmonary regurgitation. Pulmonary valve replacement was performed. Now the patient is free from infection.

Cervical aortic arch with multiple aortic aneurysms that required two aortic replacements with a 34-year interval

A 57-year old female was referred to our hospital after symptoms of hoarseness and dysphagia for a few years. She was diagnosed with a cervical vessel anomaly during childhood and had undergone surgery for a right-sided thoracic descending aortic aneurysm through a right thoracotomy at the age of 23 years. Now, enhanced computed tomography revealed newly developed multiple aneurysms in the aorta between the left carotid artery and the proximal descending aorta in the left hemithorax. A successful aortic surgical repair was accomplished via a left posterolateral thoracotomy. To our knowledge, this is the first case of a cervical aortic arch with formation of multiple aneurysms that required multiple surgeries via bilateral thoracotomies. This case suggests the inherent fragility and possibility of later aneurysmal formation in malformed vessels, thereby emphasizing the importance of periodical imaging tests in this rare congenital anomaly.

ESR Observation of Optically-Generated Polarons in Conjugated Electroluminescent Polymers

Abstract Light-induced ESR (LESR) has been employed to study optically-generated polarons in two dialkoxy derivatives of poly(p-phenylene vinylene) (PPV), MEH-PPV and CN-PPV. A clear reduction of LESR linewidth is observed in CN-PPV compared with MEH-PPV and also with PPV previously reported, providing direct evidence that the polaron spin density predominantly reside on vinyl sites. This feature can be reproduced by the linewidth analysis based on a theoretical spin distribution of a polaron extending over approximately 4 phenyl rings.

Extended total arch replacement via the L-incision approach: single-stage repair for extensive aneurysms of the aortic arch

OBJECTIVESnTotal arch replacement via the L-incision approach (a combination of left anterior thoracotomy and upper median sternotomy) can be used to achieve more extensive replacement.nnnMETHODSnIn the period between 2002 and 2014, 279 total arch replacement procedures were performed. After excluding cases of acute aortic dissection and cases involving concomitant, hybrid or frozen elephant trunk procedures, patients who underwent isolated total arch replacement via an L-incision (n = 29) and via median sternotomy (n = 143) were identified and the data pertaining to their cases were analysed.nnnRESULTSnOperative mortality was higher in the L-incision group than in the median sternotomy group (6.9 vs 2.1%); however, the difference was not statistically significant. The L-incision group displayed a higher rate of respiratory complications, including pneumonia (28 vs 7.0%, P = 0.0034), the need for tracheostomy (17 vs 2.1%, P = 0.0038) and pulmonary haemorrhage (6.9 vs 0%, P = 0.028). The rate of paraplegia was similar between the groups (0 vs 1.4%, P = 1.00), despite the wider range replaced via the L-incision approach (7.3 ± 1.5 vs 4.7 ± 0.8 anatomical zones, P < 0.001). The rates of other complications and functional recovery were similar. The long-term survival (73 vs 84% at 5 years) and aortic event-free rates (94 vs 96% at 5 years) were similar in both groups.nnnCONCLUSIONSnA combination of left anterior thoracotomy and upper median sternotomy can be applied to the single-stage repair of extended aneurysms with acceptable results in appropriately selected patients.

Strategy of Cardiovascular Surgery for Patients With Dementia as Evaluated by Mini-Mental State Examination

BACKGROUNDnThe strategy for cardiovascular surgery in dementia patients is controversial, so we aimed to investigate whether preoperative dementia and its severity might affect the outcomes of cardiovascular surgery by evaluating with the Mini-Mental State Examination (MMSE). Methodsu2004andu2004Results: The study group comprised 490 patients undergoing cardiovascular surgery. Their preoperative cognitive status was evaluated using the MMSE, and analysis was performed to compare the patients with MMSE score <24 (dementia group, n=51) or MMSE score 24-30 (non-dementia group, n=439). Furthermore, the effect of the severity of dementia was analyzed with a cut-off MMSE score of 19/20. Risk factors for surgical outcomes were explored using multivariate logistic regression analysis. Hospital mortality was 11.8% in the dementia group and 2.1% in the non-dementia group (P=0.002). Regarding the postoperative morbidities, the incidence of cerebrovascular disorder (P=0.001), pneumonia (P=0.039), delirium (P=0.004), and infection (P=0.006) was more frequent in dementia group. Among the patients with MMSE <20, hospital mortality was as high as 25%, and the rate of delirium was 58%. Multivariate logistic regression analysis revealed that MMSE score <24 (P=0.003), lower serum albumin (P=0.023) and aortic surgery (P=0.036) were independent risk factors for hospital death.nnnCONCLUSIONSnPreoperative dementia affects the outcomes of cardiovascular surgery with regard to hospital death and delirium. The surgical indication for patients with MMSE <20 might be difficult, but surgery with an appropriate strategy should be considered for patients with MMSE <24.

Early and Late Outcomes of Thoracic Aortic Surgery in Hemodialysis Patients

BACKGROUNDnThe number of cardiovascular surgeries among hemodialysis patients is increasing according to the growing population of hemodialysis patients; however, the clinical outcome has not yet been clarified, especially in thoracic aortic surgery. The purpose of this study was to assess the early and late outcomes of thoracic aortic surgery in hemodialysis patients.nnnMETHODSnWe retrospectively analyzed the outcomes of 700 consecutive open thoracic aortic surgeries from 2002 to 2014. We identified 21 patients receiving preoperative hemodialysis (group HD) and 679 patients not receiving preoperative hemodialysis (group N). The patients were predominantly male, had diabetes mellitus and cardiogenic shock, and had less hyperlipidemia and elective surgery in group HD. The early and late outcomes were compared between 21 patients in each group using a propensity-score matched analysis.nnnRESULTSnThe hospital stay and intensive care unit stay were significantly longer in group HD even after matching. The 30-day mortality and inhospital mortality showed no significant differences, whereas the rate of postoperative pneumonia was significantly higher in group HD compared with the matched group N (pxa0=xa00.0067). The 1-year, 3-year, and 7-year survival ratesxa0in group HD were 73.4%, 45.7%, and 30.5%, respectively, which were significantly poorer than that ofxa0group N both in the prematched (p < 0.001) and matched analyses (pxa0=xa00.0027).nnnCONCLUSIONSnConsidering the various operative risks associated with hemodialysis patients, the early mortalityxa0rate is acceptable, even after the association with manyxa0respiratory complications. Although hemodialysis patients have a compromised prognosis after surgery, excessive hesitation to perform thoracic aortic surgery may be avoided.

Nonbacterial Thrombotic Endocarditis Associated With Crohn Disease

This report describes an atypical case of nonbacterial thrombotic endocarditis in a mitral valve. The patient suffered repeated emboli after achieving remission of Crohn disease in the acute phase. Echocardiography revealed mitral valve leaflet and subvalvular thickening. This initially was considered indicative of infective endocarditis or a cardiac tumor; however, pathologic and laboratory examinations showed nonbacterial thrombotic endocarditis without antiphospholipid syndrome or a malignant tumor. We report a rare case of nonbacterial thrombotic endocarditis complicated with Crohn disease.

Usefulness of lymphography and computed tomography for detecting the site of chyle leakage

Chylothorax is a rare but serious complication following aortic surgery. Our patient was a 68-year-old man who underwent descending aortic replacement for a chronic dissected aortic aneurysm and in whom chylothorax postoperatively developed due to a thoracic duct injury. Although adequate medical treatment was immediately initiated at diagnosis, chyle leakage persisted. Lipiodol lymphography followed by computed tomography showed the accurate site of the leakage. Surgical repair was performed via a repeat thoracotomy with smaller incision. We were able to detect the laceration of the thoracic duct. The patient recovered and was uneventfully discharged.