An injectable hydrogel was applied to regenerate a myocardial infarction and functional recovery of the heart. A myocardial infarction was induced in rat by circumflex artery ligation. A hyaluronic acid-based hydrogel was injected into the epicardium of the infarcted area. Then, cardiac functions and regeneration of the myocardium in sham-operated (SHAM), myocardial infarction (MI), and gel-injected group (GEL) (n = 6) were evaluated 4 weeks after the injection. Measurements of the thickness of the wall showed that the thickness in the GEL group increased by up to 200% compared with that in the MI group (p < 0.001). The infarcted area of the left ventricular in the GEL group decreased by 53% compared with the MI group (p < 0.001). The number of arterioles and capillaries in the border zone of the GEL group increased by 152% and 148%, whereas the apoptotic index decreased by 42% (p < 0.05). Measurement of the heart functions, such as ejection fraction, arterial elastance (Ea), dP/dt max, and dP/dt min, indicated that the injection of a hydrogel significantly facilitated the functional recovery compared with the MI group. Because of its simplicity, easy applicability, and a great regenerating potential, this injectable hydrogel promises as a treatment for myocardial infarction.

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This study was conducted to directly compare the effects of pulsatile and nonpulsatile blood flow in the extracorporeal circulation upon renal tissue perfusion by using a tissue perfusion measurement system. A total cardiopulmonary bypass circuit was constructed to accommodate twelve Yorkshire swine, weighing 20 approximately 30 kg. Animals were randomly assigned to group 1 (n = 6, nonpulsatile centrifugal pump) or group 2 (n = 6, pulsatile T-PLS pump). A tissue perfusion measurement probe (Q-Flow 500) was inserted into the renal parenchymal tissue, and the extracorporeal circulation was maintained for an hour at a pump flow rate of 2 L/min after aortic cross-clamping. Tissue perfusion flow in the kidney was measured before bypass and every 10 minutes after bypass. Renal tissue perfusion flow was substantially higher in the pulsatile group throughout bypass (ranging 48.5-64.1 ml/min/100 g in group 1 vs. 51.0-88.1 ml/min/100 g in group 2). The intergroup difference was significant at 30 minutes (47.5 +/- 18.3 ml/min/100 g in group 1 vs. 83.4 +/- 28.5 ml/min/100 g in group 2; p = 0.026). Pulsatile flow achieves higher levels of tissue perfusion of the kidney during short-term extracorporeal circulation. A further study is required to observe the effects of pulsatile flow upon other vital organs and its long-term significance.

BackgroundWith improvements in cardiopulmonary resuscitation (CPR) techniques, the quality and the effectiveness of CPR have been established; nevertheless, the survival rate after cardiac arrest still remains poor. Recently, many reports have shown good outcomes in cases where extracorporeal membrane oxygenation (ECMO) was used during prolonged CPR. Accordingly, we attempted to evaluate the impact of extracorporeal cardiopulmonary resuscitation (ECPR) on the survival of patients who experienced a prolonged cardiac arrest and compared it with that of conventional CPR (CCPR).MethodsBetween March 2009 and April 2014, CPR, including both in-hospital and out-of-hospital CPR, was carried out in 955 patients. The ECPR group, counted from the start of the ECPR program in March 2010, included 81 patients in total, and the CCPR group consisted of 874 patients. All data were retrospectively collected from the patients’ medical records.ResultsThe return of spontaneous circulation (ROSC) rate was 2.24 times better in CPR of in-hospital cardiac arrest (IHCA) patients than in CPR of out-of-hospital CA (OHCA) patients (p=0.0012). For every 1-minute increase in the CPR duration, the ROSC rate decreased by 1% (p=0.0228). Further, for every 10-year decrease in the age, the rate of survival discharge increased by 31%. The CPR of IHCA patients showed a 2.49 times higher survival discharge rate than the CPR of OHCA patients (p=0.03). For every 1-minute increase in the CPR duration, the rate of survival discharge was decreased by 4%. ECPR showed superiority in terms of the survival discharge in the univariate analysis, although with no statistical significance in the multivariate analysis.ConclusionThe survival discharge rate of the ECPR group was comparable to that of the CCPR group. As the CPR duration increased, the survival discharge and the ROSC rate decreased. Therefore, a continuous effort to reduce the time for the decision of ECMO initiation and ECMO team activation is necessary, particularly during the CPR of relatively young patients and IHCA patients.