Hiroyuki Muranaka

Results of surgical treatment of lung cancer in octogenarians

The treatment of potentially resectable lung cancer in octogenarians has become a frequent clinical problem, due to the increasing number of elderly people maintaining an active daily life. In the present study, we reviewed the clinical records of patients to evaluate the results of the surgical treatment of lung cancer in octogenarians. From 1992 to 1995, 18 patients aged 80 years or older (octogenarians) with primary lung cancer underwent surgical resections including: three (16.7%) sleeve lobectomies, nine (50.0%) lobectomies, one (5.5%) segmentectomy, and five (27.8%) partial resections. The postoperative complication rate was 50% in octogenarians; however, no fatal complications were observed. The 5-year survival rate was 42.6%, which was similar to that obtained in younger patients. Based on our findings, the surgical treatment of lung cancer can thus be performed in selected octogenarians without increasing either morbidity or mortality, while also obtaining long-term survival.

Maximal period of cryopreservation with the bicell biofreezing vessel for rat tracheal isografts

OBJECTIVE The maximal period of cryopreservation for the trachea is still unsolved. We assessed the maximal period of cryopreservation using the Bicell biofreezing vessel as an easy and cheap slow-freezing instrument for viable tracheal grafts in 95 rats. METHODS Each isograft was harvested from 17 donor rats, immersed in the preservative solution, and stored in a Bicell device in a deep freezer at -80 degrees C. The tracheal isografts were then randomly assigned to 9 groups according to cryopreservation periods ranging from 0 to 12 months. Included in the 9 groups were 2 subgroups (n = 6 per subgroup) that were observed immediately after being thawed and 1 month after heterotopic transplantation into the omentum after being thawed. Four subgroups (n = 6 per subgroup) were added according to the cryopreservation period for 1, 3, 6, and 12 months to evaluate the graft morphology 3 months after being thawed and transplanted heterotopically. RESULTS A prolonged period of cryopreservation had a degenerative effect on both the epithelium and cartilage. One month after transplantation, degeneration was more pronounced in the cartilage than in the epithelium, as characterized by the viable chondrocyte ratio and the epithelial score of isografts undergoing cryopreservation for more than 9 months. Three months after transplantation, the morphology of the epithelium and cartilage in isografts undergoing cryopreservation for less than 3 months was better preserved, whereas the morphology of both deteriorated in isografts undergoing cryopreservation for more than 6 months. CONCLUSIONS We conclude that the permissible period of cryopreservation to maintain tracheal isograft viability in this simple system using a Bicell biofreezing vessel is 3 months.

Effect of cryopreservation period on rat tracheal allografts

BACKGROUND The effect of cryopreservation on tracheal allogenicity is still unclear. Therefore, in this study, we assessed the effect of cryopreservation period on tracheal allografts in 62 rats. METHODS Each transplant consisted of a 3-ring segment of the trachea harvested from 8 Lewis rats, immersed in preservation solution, and cryopreserved and stored in a Bicell biofreezing vessel in a deep freezer at -80 degrees C. Six tracheal grafts without cryopreservation that underwent a heterotopically syngeneic transplantation into the omentum served as controls. Forty-eight tracheal segments were randomly assigned to 8 groups according to period of cryopreservation, which ranged from 0 to 12 months (0, 0.5 [2 weeks], 1, 2, 3, 6, 9 and 12 months). The cryopreserved grafts were then thawed and heterotopically implanted into the omentum of recipient Brown-Norway rats. After 28 days, the tracheal segments were then evaluated histologically. RESULTS All isografts in Group 1 were intact, whereas the allografts undergoing a particularly shorter period of cryopreservation showed a more stenotic lumen. Prolonged periods of cryopreservation tended to show decreasing tendencies of viability of chondrocytes, mononuclear cell infiltration and sub-epithelial thickness, whereas all allografts showed a uniformly denuded epithelium, irrespective of the length of cryopreservation. CONCLUSIONS A longer period of cryopreservation may help to maintain a better patency of tracheal allografts by preventing an allogeneic response. Reduced tracheal allogenicity may be associated with a decreased viability of chondrocytes by cryopreservation.

Impact of diabetes mellitus on outcomes in Japanese patients undergoing coronary artery bypass grafting

BACKGROUND AND PURPOSE There have been no large-scale studies on the impact of diabetes mellitus (DM) on outcomes in Japanese patients undergoing coronary artery bypass grafting (CABG). METHODS AND SUBJECTS A multi-institutional retrospective cohort study was conducted in 14 Japanese centers. All adult patients who underwent isolated CABG from 2007 to 2008 were included (n=1522, mean age: 68.5years). The definitions of DM were all patients admitted with diagnosis of DM and preoperative glycated hemoglobin (Hb) A1c≥6.5%. Univariate and multivariate analyses were performed to identify the risk of morbidity and mortality. RESULTS There were 849 DM and 572 non-DM patients. Preoperative mean HbA1c were 7.1% in the DM group and 5.7% in the non-DM group (p<0.0001). Preoperative, intraoperative, and 3-day average postoperative blood glucose (BG) were 146mg/dl, 172mg/dl, and 168mg/dl in the DM group, and 103mg/dl, 140mg/dl, and 136mg/dl in the non-DM group (all p<0.0001). Although there were no significant differences in postoperative cardiovascular events, the incidence of infection was significantly higher in the DM group than in the non-DM group (9.2% vs 6.1%, p=0.036) on the univariate analysis. The all-cause death was also relatively higher in the DM group than in the non-DM group (2.1% vs 1.1%, p=0.12), and this was likely related to infection. CONCLUSION DM patients had worse perioperative BG control, higher incidence of infection, and higher mortality than non-DM patients. These results indicate that perioperative BG control guidelines should be standardized to obtain better surgical outcomes in Japanese DM patients.

The immunomodulatory effect of cryopreservation in rat tracheal allotransplantation

BACKGROUND Cryopreservation is one solution to the problem of donor organ deficit. To investigate the effect of cryopreservation on tracheal allografts, we performed 2 experiments in rats. METHODS In Experiment 1, we assessed second-set graft rejection. Two weeks after primary heterotopic transplantation (Group 1, fresh isografts; Group 2, fresh allografts from Lewis rats; and Group 3, cryopreserved allografts from Lewis rats; n = 5, respectively), each animal underwent secondary heterotopic grafting with isografts and allografts from Lewis and Wistar Furth rats (n = 5, respectively). Four weeks after the secondary transplantation, all grafts were retrieved for histologic analysis. In Experiment 2, we assessed the long-term results of allograft cryopreservation, without immunosuppression therapy. Six months after transplantation of fresh (Group 4) and cryopreserved (Group 5) allografts, the tracheal segments (each group, n = 5) were histologically evaluated. RESULTS In Experiment 1, only the secondary allografts from Lewis rats in Group 2 did not maintain lumen structure and often showed dislocated or destroyed cartilage. Second-set graft rejection was specifically recognized in Group 2, but not in Group 1 or 3. In Experiment 2, the cryopreserved allografts appeared almost normal and lumen rigidity was preserved 6 months after transplantation. These allografts were superior to the fresh allografts in patency and in cartilage dislocation and mononuclear cell infiltration scores, but not in the viable chondrocyte ratio. CONCLUSIONS We conclude that cryopreservation may produce successful long-term results because of its immunomodulatory effect on tracheal allografts.

Limit of warm ischemia time before cryopreservation in rat tracheal isografts

BACKGROUND The viability of cadaveric tracheal grafts undergoing cryopreservation is still unclear. We evaluated the limit of warm ischemia time before cryopreservation in rat tracheal isografts. METHODS Each isograft was harvested from donor rats 0 to 48 hours (0, 6, 12, 18, 24, and 48 hours) after circulatory arrest, immersed in the preservative solution, and stored in a deep freezer until reaching -80 degrees C and then was kept in liquid nitrogen for 3 months. Heterotopic transplantation into the omentum was performed after the isografts were thawed. Graft morphology 3 months after transplantation was assessed. RESULTS The stepwise increase of warm ischemia time significantly reduced graft survival. A prolonged period of warm ischemia had a degenerative effect on both the epithelium and cartilage. The morphology of the epithelium and cartilage in isografts undergoing warm ischemia for less than 18 hours was better preserved, whereas it deteriorated in isografts undergoing warm ischemia for more than 24 hours. CONCLUSIONS We thus conclude that the permissible period of warm ischemia before 3-month cryopreservation to maintain tracheal isograft viability is 18 hours in rats.

Clinical Characteristics and Social Frailty of Super-Elderly Patients With Heart Failure - The Kitakawachi Clinical Background and Outcome of Heart Failure Registry.

BACKGROUND Social background is important in preventing admission/readmission of heart failure (HF) patients. However, few clinical studies have been conducted to assess the social background of these patients, especially elderly patients.Methods and Results:The Kitakawachi Clinical Background and Outcome of Heart Failure (KICKOFF) Registry is a prospective multicenter community-based cohort of HF patients, established in April 2015. We compared the clinical characteristics and social background of the super-elderly group (≥85 years old) and the non-super-elderly group (<85 years old). This study included 647 patients; 11.8% of the super-elderly patients were living alone, 15.6% were living with only a partner, and of these, only 66.7% had the support of other family members. The super-elderly group had less control over their diet and drug therapies than the non-super-elderly group. Most patients in the super-elderly group were registered for long-term care insurance (77.4%); 73.5% of the super-elderly patients could walk independently before admission, but only 55.5% could walk independently at discharge, whereas 94% of the non-super-elderly patients could walk independently before admission and 89.4% could walk independently at discharge. CONCLUSIONS The KICKOFF Registry provides unique detailed social background information of Japanese patients with HF. Super-elderly patients are at serious risk of social frailty; they need the support of other people and their ability to perform activities of daily living decline when hospitalized.

Carvedilol may alleviate late cardiac remodelling following surgical ventricular restoration

OBJECTIVE Surgical ventricular restoration (SVR) can be effective to treat ischaemic cardiomyopathy or left ventricular (LV) aneurysm. However, the initial improvement in LV function does not always last long because of LV remodelling. Beta-blockers prevent LV remodelling of failing hearts; however, their effects following SVR have not been elucidated. Thus, we sought to investigate the effects of a potent beta-blocker, carvedilol, on LV remodelling and function following SVR in rats with myocardial infarction. METHODS Rats, which developed LV aneurysm 4 weeks after coronary artery ligation, underwent SVR. They were orally administered a vehicle (vehicle group), and low or high dose of carvedilol (20 or 50 mg kg(-1)day(-1) for C20 or C50 group) for 4 weeks following SVR (n=7 in each group). RESULTS Four weeks following SVR, late cardiac remodelling was alleviated only in the C50 group (LV end-diastolic area: 65+/-4 mm(2) vs 74+/-11 mm(2) and 76+/-11 mm(2) for C50, C20 and vehicle groups; p=0.039 and p=0.013, respectively). There was no difference in LV systolic function (end-systolic elastance) among the three groups; however, LV diastolic functions (LV end-diastolic pressure and the time constant of isovolumic relaxation) were significantly better in the C20 and C50 groups. Histologically, the percentage of myocardial fibrosis in the C50 group (4.1+/-0.2%) was lower than those in the C20 (6.7+/-0.4%, p<0.0001) and vehicle (7.5+/-0.6%, p<0.0001) groups. The mRNA expression of transforming growth factor-beta1 and brain natriuretic peptide in the C50 group were lower than those in the C20 and the vehicle groups. CONCLUSIONS High-dose carvedilol alleviated LV remodelling and diastolic dysfunction following SVR accompanying with reduction in myocardial fibrosis. Blockade of beta-adrenergic receptor may be a promising adjuvant therapy in patients following SVR.

A syndrome of inappropriate secretion of antidiuretic hormone associated with pleuritis caused by OK-432

We here report a case presenting with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) after having been treated for pleurodesis with OK-432, which is a lyophilized preparation of an attenuated strain of Streptococcus pyogenes. The patient, who had undergone a subtotal esophagectomy 4 years previously, was referred to our department after the diagnosis of a metastatic lung tumor. A right lower lobectomy of the lung was performed, and prolonged air leakage from a pulmonary fistula thereafter developed because of the dissection of severe pleural adhesion. OK-432 (5 klinische einheiten) was administered to the pleural cavity 3 times. On the 13th postoperative day, the patient began to complain of general fatigue and nausea. SIADH was diagnosed based on laboratory findings such as hyponatremia, serum hypo-osmolality and a high excretion of sodium in the urine. A restriction of the fluid intake with a sodium supplement resulted in the return to a normal serum level within 2 weeks. We therefore concluded that the intrapleural instillation of OK-432 had apparently caused SIADH in this case, because no other causes could be found.

Effects of hepatocyte growth factor in myocarditis rats induced by immunization with porcine cardiac myosin

OBJECTIVES Myocarditis is considered one of the major causes of dilated cardiomyopathy. Hepatocyte growth factor (HGF) has pleiotropic activities that promote tissue regeneration and facilitate functional improvement of injured tissue. We investigated whether the epicardial sustained-release of HGF, using gelatin hydrogel sheets, improves cardiac function in a chronic myocarditis rat model. METHODS Six weeks after Lewis rats were immunized with porcine cardiac myosin to establish autoimmune myocarditis, HGF- or normal saline (NS)-incorporated gelatin hydrogel sheets were applied to the epicardium (G-HGF and G-NS, respectively). At either 2 or 4 weeks after treatment, these were compared with the Control myocarditis group. Cardiac function was evaluated by echocardiography and cardiac catheterization. Development of fibrosis was determined by histological study and expression of transforming growth factor-β1 (TGF-β1). Bax and Bcl-2 levels were measured to evaluate apoptotic activity. RESULTS At both points, fractional shortening and end-systolic elastance were higher in the G-HGF group than in the Control and G-NS groups (P < 0.01). Fractional shortening at 2 weeks of each group were as follows: 31.0 ± 0.9%, 24.8 ± 2.7% and 48.6 ± 2.6% (Control, G-NS and G-HGF, respectively). The ratio of the fibrotic area of the myocardium was lower in the G-HGF group than in the Control and G-NS groups at 2 weeks (G-HGF, 8.8 ± 0.9%; Control, 17.5 ± 0.2%; G-NS, 15.6 ± 0.7%; P < 0.01). The ratio at 4 weeks was lower in the G-HGF group than in the G-NS group (10.9 ± 1.4% vs 18.5 ± 1.3%; P < 0.01). The mRNA expression of TGF-β1 in the G-HGF group was lower than in the Control group at 2 weeks (0.6 ± 0.1 vs 1.1 ± 0.2) and lower than that in the G-NS group at 4 weeks (0.7 ± 0.1 vs 1.3 ± 0.2). The Bax-to-Bcl-2 ratios at both points were lower in the G-HGF group than in the Control group. CONCLUSIONS Sustained-released HGF markedly improves cardiac function in chronic myocarditis rats. The antifibrotic and antiapoptotic actions of HGF may contribute to the improvement. HGF-incorporated gelatin hydrogel sheet can be a new therapeutic modality for myocarditis.