Getting to the heart of the matter Glower, Donald, MD
The Journal of thoracic and cardiovascular surgery,
03/2015, Volume:
149, Issue:
3
Journal Article
Purpose: Sivelestat, a neutrophil elastase inhibitor, attenuates global ischemia-induced myocardial damage and coronary endothelial dysfunction. Here, we investigated whether sivelestat exerts the ...cardioprotective effects against cardioplegic arrest in rat hearts.Methods: Isolated Langendorff-perfused rat hearts were randomly allocated to three groups and subjected to 2-min infusions with St. Thomas’ Hospital cardioplegic solution No. 2 (STH2) and 30-min global ischemia followed by 60-min reperfusion as follows: (i) control (STH2 treatment only), (ii) sivelestat (19 μmol/L) infusion for the first 10 min of reperfusion, and (iii) sivelestat (19 μmol/L) infusion for 10 min before ischemia and for the first 10 min of reperfusion. Left ventricular developed pressure (LVDP) recovery and troponin T leakage were measured at the end of reperfusion. Coronary flow response to acetylcholine (ACh) was assessed.Results: Single and multiple doses of sivelestat significantly improved LVDP recovery (69 ± 15 and 69 ± 14 vs 48 ± 15 control; p <0.05) and decreased troponin T leakage (0.4 ± 0.3 and 0.7 ± 0.5 vs 1.7 ± 0.6 control; p <0.05). Multiple doses of sivelestat significantly improved coronary flow response to ACh (121 ± 9 vs 105 ± 4; p <0.05).Conclusions: Addition of sivelestat to STH2 attenuates myocardial injury after cardioplegic arrest in rat hearts. This cardioprotective effect was achieved even when sivelestat was administered during early reperfusion.
Background. The pig has become an increasingly popular model for the study of cerebral protection during cardiothoracic surgery in recent years, but little information is available concerning ...hypothermic porcine physiology. Because the efficacy of cerebral protection depends largely upon metabolic suppression, we studied cerebral oxygen metabolism at various temperatures using two different methods to assess cerebral blood flow (CBF).
Material and Methods. Twelve pigs (7 to 13 kg) underwent cooling on cardiopulmonary bypass to 8°C as recorded by an electrode placed deep in the parenchyma of the brain. CBF was measured in 6 animals using radioactive microspheres and in the other 6 using fluorescent microspheres. CBF, cerebral oxygen consumption, and cerebral vascular resistance were determined at 37°C, 28°C, 18°C, and 8°C.
Results. Both methods produced very similar data. CBF fell steadily with decrease in temperature to 18°C but failed to drop further with more profound hypothermia. With both groups combined, mean cerebral oxygen metabolism was 2.63 mL/100 g per minute at 37°C. Metabolic activity was 50% of base line values at 28°C, 19% at 18°C, and 11% at 8°C. The Q
10 value in the pig—the degree of metabolic suppression achieved by a 10°C drop in temperature—is 2.46 (95% confidence interval 2.1 to 2.9); this value is consistent with similar studies in humans.
Conclusions. The presence of significant residual metabolic activity at 18°C suggests that this degree of hypothermia may provide incomplete cerebral protection during prolonged interruption of CBF. This study demonstrates that cooling to temperatures below 18°C in the pig can achieve greater metabolic suppression although it may be associated with loss of cerebral autoregulation.
Restrictive fluid management may protect organ function and improve postoperative outcome in elderly coronary artery bypass grafting (CABG) patients.
We assessed organ-specific biomarker release to ...study the contribution of a fluid restrictive closed circuit concept to organ protection in elderly CABG patients. Cardiac, respiratory and abdominal organ injury was measured during and following minimal fluid coronary artery bypass grafting (mCABG), off-pump coronary artery bypass (opCAB) surgery and conventional CABG with high volume prime and cold crystalloid cardioplegia (cCABG). The results were related to differences in clinical outcome.
Prospective randomised trial.
Dutch tertiary single centre study.
Sixty patients over 70 years of age (38 men and 22 women) were randomised to one of the three different techniques. Inclusion criteria were as follows: first time CABG, elective surgery, ejection fraction more than 30% and multivessel disease. Acetylsalicylic acid and clopidogrel administration or requiring less than three distal anastomoses were an exclusion.
Organ-specific markers of the heart--heart fatty acid binding protein (HFABP), troponin T, pro-brain natriuretic peptide (pro-BNP) and creatinine phosphokinase (CPK), lung clara cell 16 protein, pneumoprotein (CC16), intestinal fatty acid binding protein (IFABP) and liver glutathione S-transferase (α-GST)--were measured perioperatively. Postoperative PaO2 levels, ventilation time, blood product consumption and adverse events were noted.
Myocardial organ-specific biomarker troponin T showed significantly lower median levels during mCABG compared with the cCABG and opCAB groups troponin 0.25 mg l(-1) (interquartile range, IQR 0.18 to 0.40), 0.39 mg l(-1) (IQR 0.23 to 0.49) and 0.36 mg l(-1) (IQR 0.23 to 0.50), respectively (P<0.003). HFABP, IFABP and α-GST levels were significantly higher during cCABG compared with opCAB and mCABG HFABP 38.6 mg l(-1) (IQR 29.6 to 47.1), 23.3 mg l(-1) (IQR 16.5 to 31.0) and 21.1 mg l(-1) (IQR 15.7 to 28.8; P<0.001), IFABP 0.57 mg l(-1) (IQR 0.37 to 1.11), 0.44 mg l(-1) (IQR 0.16 to 0.74) and 0.37 mg l(-1) (IQR 0.13 to 1.05; P<0.02) and α-GST 11.5 mg l(-1) (IQR 7.7 to 15.7), 7.0 mg l(-1) (IQR 4.5 to 13.8) and 7.3 mg l(-1) (IQR 6.2 to 11.2), respectively (P<0.009). There was a trend towards higher median CC16 levels in the cCABG group (P<0.07). CPK and pro-BNP were not significantly different. On the first postoperative day, PaO2 levels and duration of mechanical ventilation were significantly improved, and there was lower use of blood products in the mCABG group than in the cCABG and opCAB groups (P<0.05).
Following mCABG with low volume myocardial preservation and restrictive fluid management, early respiratory performance was improved and consumption of blood products reduced compared with opCAB and cCABG.
Aortic arch repair: let it beat Rüffer, A; Klopsch, C; Münch, F ...
The Thoracic and cardiovascular surgeon,
04/2012, Volume:
60, Issue:
3
Journal Article
Peer reviewed
Objective aortic arch repair (AAR) on the beating heart may reduce cross-clamping times and offer improved postoperative cardiac function.Methods A single-center review of all patients (n = 24) who ...underwent surgical AAR during biventricular repair between 01/2006 and 01/2008 was done. All patients were operated on under cardiopulmonary bypass (CPB) with antegrade cerebral perfusion (ACP). During AAR, 13 patients (group 1) received cardioplegic arrest, and were compared to 11 patients (group 2) who underwent a beating-heart modification with selective myocardial perfusion. Seventeen patients had additional intracardiac lesions and underwent simultaneous correction during the procedure.Results Durations of CPB, AAR and ACP did not differ statistically between groups. Cardioplegic arrest time was significantly lower in group 1 (34 ± 13 vs. 76 ± 11 min, p = 0.02) and resulted in a subsequent reduction of myocardial ischemic damage as borne out by lower postoperative levels of troponin T and CK-MB (2.5 ± 0.7 vs. 7.1 ± 1.4 ng/mL, p = 0.02; 68.7 ± 11.5 vs. 149.1 ± 27.2 U/l, p = 0.03). We observed an enhanced patient recovery with shorter inotropic and ventilatory support times (p < 0.05).Conclusion Pediatric aortic arch correction on a CPB beating heart with selective myocardial perfusion is technically feasible and safe. The reduction of the myocardial ischemic time is effective and results in less myocardial damage.
Background:
Cardioplegic solutions are the standard in myocardial protection during cardiac surgery, since they interrupt the electro-mechanical activity of the heart and protect it from ischemia ...during aortic cross-clamping. Nevertheless, myocardial damage has a strong clinical impact. We tested the hypothesis that the short-acting beta-blocker esmolol, given immediately before cardiopulmonary bypass and as a cardioplegia additive, would provide an extra protection to myocardial tissue during cardiopulmonary bypass by virtually reducing myocardial activity and, therefore, oxygen consumption to zero.
Materials and methods:
This was a single-centre, double-blind, placebo-controlled, parallel-group phase IV trial. Adult patients undergoing elective valvular and non-valvular cardiac surgery with end diastolic diameter >60 mm and ejection fraction <50% were enrolled. Patients were randomly assigned to receive either esmolol, 1 mg/kg before aortic cross-clamping and 2 mg/kg with Custodiol® crystalloid cardioplegia or equivolume placebo. The primary end-point was peak postoperative troponin T concentration. Troponin was measured at Intensive Care Unit arrival and at 4, 24 and 48 hours. Secondary endpoints included ventricular fibrillation after cardioplegic arrest, need for inotropic support and intensive care unit and hospital stay.
Results:
We found a reduction in peak postoperative troponin T, from 1195 ng/l (690–2730) in the placebo group to 640 ng/l (544–1174) in the esmolol group (p=0.029) with no differences in Intensive Care Unit stay 3 days (1-6) in the placebo group and 3 days (2-5) in the esmolol group and hospital stay 7 days (6–10) in the placebo group and 7 days (6–12) in the esmolol group. Troponin peak occurred at 24 hours for 12 patients (26%) and at 4 hours for the others (74%). There were no differences in other secondary end-points.
Conclusions:
Adding esmolol to the cardioplegia in high-risk patients undergoing elective cardiac surgery reduces peak postoperative troponin levels. Further investigation is necessary to assess esmolol effects on major clinical outcomes.
Abstract Background We measured the functional and metabolic status of hearts submitted to normothermic ischemia before preservation through the use of an ex vivo pig heart model to assess the ...feasibility of donation after cardiac death (DCD) in heart transplantation. Methods Ten pigs were separated into 2 groups: control ( n = 6, brain-dead group) and DCD ( n = 4, heart donation after cardiac death). In the control group, hearts were excised 20 minutes after the brachiocephalic trunk cross-clamping and were immediately reperfused. In DCD, hearts were excised 20 minutes after exsanguination and asphyxia, stored in the Centre de Résonance Magnétique Biologique et Médicale (CRMBM) solution for 2 hours, and then were reperfused. Cardioplegic arrest was induced with the use of 1 L of CRMBM solution (4°C) and the heart was reperfused for 60 minutes through the use of an ex vivo perfusion system in Langendorff mode with normothermic autologous blood. During reperfusion, functional parameters were analyzed. Biochemical assays were performed in myocardial effluents and freeze-clamped hearts. Results No electromechanical activity was found in DCD compared with control. Creatine kinase (CK) was higher at 2 minutes of reperfusion in DCD versus control ( P = .005). Adenosine triphosphate was lower in DCD versus control ( P = .0019). Malondialdehyde, an oxidative stress index, was present only in DCD. The nitric oxide (NO) pathway was impaired in DCD versus control, with lower eNOS expression ( P < .0001) and total nitrate concentration content ( P = .04). Conclusions We reported no cardiac functional and metabolic recovery in the DCD group after normothermic ischemia and reperfusion, which indicates that a single immersion of the cardiac graft during storage does not provide an optimal protection. New strategies in heart preservation are necessary for recruiting heart donation after cardiac death.
Intravenous extension of benign uterine leiomyomata ('fibroids'), in the absence of discrete metastatic disease has rarely been reported. 'Fibroids' remain one of the most common premenopausal ...uterine pathologies.
We report the diagnosis and multidisciplinary led operative management of a 52-year-old woman with a histologically benign, but biologically aggressive, uterine leiomyoma with intravenous extension to the inferior vena cava (IVC), right heart and pulmonary arteries.
Total abdominal hysterectomy and bilateral salpingo-oophorectomy combined with exploration of the sub-hepatic IVC and heart under deep hypothermic circulatory arrest achieved its successful macroscopic clearance.
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