State of the art in neuroprotection during acute type A aortic dissection repair.

Temporary (TND) or permanent neurologic dysfunctions (PND) represent the main neurological complications following acute aortic dissection repair. The aim of our experimental and clinical research was the improvement and update of the most common neuroprotective strategies which are in present use. HYPOTHERMIC CIRCULATORY ARREST (HCA): Cerebral metabolic suppression at the clinically most used temperatures (18-22°C) is less complete than had been assumed previously. If used as a 'stand-alone' neuroprotective strategy, cooling to 15-20°C with a jugular SO(2) ≥ 95% is needed to provide sufficient metabolic suppression. Regardless of the depth of cooling, the HCA interval should not exceed 25 min. After 40 min of HCA, the incidence of TND and PND increases, after 60 min, the mortality rate increases. ANTEGRADE SELECTIVE CEREBRAL PERFUSION (ASCP): At moderate hypothermia (25-28°C), ASCP should be performed at a pump flow rate of 10ml/kg/min, targeting a cerebral perfusion pressure of 50-60mmHg. Experimental data revealed that these conditions offer an optimal regional blood flow in the cortex (80±27ml/min/100g), the cerebellum (77±32ml/min/100g), the pons (89±5ml/min/100g) and the hippocampus (55±16ml/min/100g) for 25 minutes. If prolonged, does ASCP at 32°C provide the same neuroprotective effect? CANNULATION STRATEGY: Direct axillary artery cannulation ensures the advantage of performing both systemic cooling and ASCP through the same cannula, preventing additional manipulation with the attendant embolic risk. An additional cannulation of the left carotid artery ensures a bi-hemispheric perfusion, with a neurologic outcome of only 6% TND and 1% PND. NEUROMONITORING: Near-infrared spectroscopy and evoked potentials may prove the effectiveness of the neuroprotective strategy used, especially if the trend goes to less radical cooling. CONCLUSION: A short interval of HCA (5 min) followed by a more extended period of ASCP (25 min) at moderate hypothermia (28°C), with a pump flow rate of 10ml/kg/min and a cerebral perfusion pressure of 50 mmHg, represents safe conditions for open arch surgery.

Impact of urgent coronary artery bypass grafting on acute kidney injury : A matched cohort study.

OBJECTIVES: There is limited knowledge regarding the specific interrelationships between urgent coronary artery bypass graft (U-CABG) surgery and postoperative acute kidney injury (AKI). We aimed to (1) analyze the impact of urgent CABG (U-CABG) on the incidence and severity of postoperative AKI, (2) estimate the influence of AKI after U­CABG or elective CABG (E-CABG) on mortality and (3) identify risk factors for AKI depending on the urgency of operation. RESULTS: U­CABG patients showed a higher incidence of AKI (49.8% vs. E­CABG: 39.7%; p = 0.026), especially for higher AKI stages 2 + 3. In-hospital mortality was higher in U­CABG patients (12.6%) compared to E­CABG patients (2.3%; p < 0.001). The impact of AKI on mortality did not differ, but showed a strong coherency between higher AKI stages (2 + 3) and mortality (stage 1: OR 2.409, 95% CI 1.017-5.706; p = 0.046 vs. stage 2 + 3: OR 5.577; 95% CI 2.033-15.3; p = 0.001). Univariate logistic regression analysis revealed that preoperative renal impairment, peripheral vascular disease and transfusion of more than two red blood cell concentrates were predictors for postoperative AKI in both groups. CONCLUSIONS: U­CABG is a risk factor for postoperative AKI and even "mild" AKI leads to a significantly higher mortality. Hence, the prevention of modifiable risk factors might reduce the incidence of postoperative AKI and thus improve outcome.

The acute effect of IABP-induced pulsatility on coronary vascular resistance and graft flow in critical ill patients during ECMO.

AIM: The combination of the two cardiac support mechanisms of intra-aortic balloon pumping (IABP) and non-pulsatile circulatory extracorporeal membrane oxygenation (ECMO) has been confirmed to improve efficacy of the cardiac support as a whole. However, reports on benefits of diastolic augmentation on coronary vascular bed and graft flowmetry during concomitant use of IABP and ECMO are lacking. The aim of this study was to evaluate the acute impact of IABP support on coronary vascular resistance (CVR) and coronary bypass flows (CBF) in high-risk patients with peripheral ECMO following coronary artery bypass grafting (CABG). METHODS: In eight emergency CABG patients (mean age=67.8±1.9 years; gender: six male and two female; EF=25.5±2.4%) requiring mechanical circulatory support with ECMO hemodynamic parameters, CVR, CBF, diastolic filling index (DFI), graft flow reserve (GFR), and pulsatility index (PI) were analyzed with and without diastolic augmentation using a transit time flowmeter. RESULTS: The addition of IABP to ECMO decreased CVR significantly by 6.5%±1.9% compared to baseline with ECMO alone (1.62±0.2 versus 1.78±0.2; P<0.0045). Accordingly, significant higher mean CBF were found during IABP assist, resulting in a 21.6%±2.6% increase (60.7±8.7 mL/min with versus 51.3±7.4 mL/min without IABP; P<0.0001). IABP also significantly increased DFI by 9.8±0.9% (73.2%±1.4% with versus 66.7%±1.3% without IABP; P<0.0001). GFR was recruited during IABP in all grafts (GFR>1). There were no statistically significant differences in PI with and without IABP assistance (2.6±0.1 versus 2.5±0.2). CONCLUSION: IABP-induced pulsatility significantly improves diastolic filling index and mean coronary bypass graft flows by lowering coronary vascular resistance during non-pulsatile peripheral ECMO. The combination of ECMO with IABP may provide more optimal myocardial oxygen conditions resulting in an improved efficacy of the cardiac support as a whole in critical ill patients with postcardiotomy myocardial dysfunction following CABG.

Preliminary results of small arterial substitute performed with a new cylindrical biomaterial composed of bacterial cellulose.

OBJECTIVE: Tissue-engineered blood vessels (TEBVs) represent an innovative approach for overcoming reconstructive problems associated with extended vascular diseases by providing small-calibre vascular grafts. This study aimed to evaluate a novel biomaterial of bacterially synthesised cellulose (BC) as a potential scaffold for TEBV. METHODS: Highly crystalline cellulose was produced by a bacterium (Acetobacter xylinum) using glucose as a source of carbon. Using a patented process, hollow-shaped segments of BC were created with a length of 10mm, an inner diameter of 3.0-3.7mm and a wall thickness of 0.6-1.0mm. These grafts were used to replace the carotid arteries of eight pigs, and after a follow-up period of 3 months, the grafts were removed and analysed, both macro- and microscopically. RESULTS: Seven grafts (87.5%) remained patent, whereas one graft was found to be occluded. Scanning electron microscopic examination revealed rapid re-cellularisation by recipient endothelial cells. Light microscopic examination showed a three-layered wall structure of the BC segments, with cellulose still being present in the media. CONCLUSION: These data indicate that the innovative BC-engineering technique results in the production of stable vascular conduits, which exhibit attractive properties for their use in future TEBV programmes for vascular surgery.

[Cave canulam et dilatationem. Cardiopulmonary resuscitation and surgical repair of a vessel perforation following central venous catheterization]. / Cave canulam et dilatationem. Management einer reanimationsbedürftigen Gefässverletzung nach zentralvenöser Kanülierung.

A 58-year-old female patient was scheduled for minimally invasive cardiac surgery. For drainage of venous blood to the heart-lung machine insertion of a central venous large diameter catheter was a prerequisite. During insertion into the right internal jugular vein by the anesthesiologist a life-threatening perforation of the subclavian artery occurred. The patient suffered hemorrhagic shock and advanced cardiac life support was carried out for approximately 18 min. Immediate surgical repair was successful and the originally planned operation was then performed. Concurrently, mild therapeutic hypothermia was established for 24 h to protect the cerebrum. Within 4 days the patient recovered without any neurological deficits.

Preischemic iloprost application for improvement of graft preservation: which route is superior in experimental pig lung transplantation: inhaled or intravenous?

BACKGROUND: Optimal allograft protection is essential in lung transplantation to reduce postoperative organ dysfunction. Although intravenous prostanoids are routinely used to ameliorate reperfusion injury, the latest evidence suggests a similar efficacy of inhaled prostacyclin. Therefore, we compared donor lung-pretreatment using inhaled lioprost (Ventavis) with the commonly used intravenous technique. METHODS: Five pig lungs were each preserved with Perfadex and stored for 27 hours without (group 1) or with (group-2, 100 prior aerosolized of iloprost were (group 3) or iloprost (IV). Following left lung transplantation, hemodynamics, Po(2)/F(i)o(2), compliance, and wet-to-dry ratio were monitored for 6 hours and compared to sham controls using ANOVA analysis with repeated measures. RESULTS: The mortality was 100% in group 3. All other animals survived (P < .001). Dynamic compliance and PVR were superior in the endobronchially pretreated iloprost group as compared with untreated organs (P < .05), whereas oxygenation was comparable overall W/D-ratio revealed significantly lower lung water in group 2 (P = .027) compared with group 3. CONCLUSION: Preischemic alveolar deposition of iloprost is superior to IV pretreatment as reflected by significantly improved allograft function. This strategy offers technique to optimize pulmonary preservation.

Transcriptomic and proteomic patterns of systemic inflammation in on-pump and off-pump coronary artery bypass grafting.

BACKGROUND: Coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB) provides controlled operative conditions but induces a whole-body inflammatory response capable of initiating devastating morbidity and mortality. Although technically more demanding, deliberate avoidance of CPB in off-pump surgery attenuates the physiological insult associated with CABG. METHODS AND RESULTS: To systematically assess the molecular mechanisms underlying the better-preserved remote organ function, we studied gene expression patterns in leukocytes and plasma proteomic response to on-pump and off-pump CABG. Proteomic analysis confirmed (tumor necrosis factor-alpha, interleukin [IL]-6, IL-10) and expanded (eg, interferon [IFN]-gamma, granulocyte colony-stimulating factor [G-CSF], monocyte chemotactic protein-1, macrophage inflammatory protein-1beta) the mediators released on CPB, whereas blood leukocyte transcriptomics suggested that circulating leukocytes are not primarily responsible for this response. Interestingly, release of some cytokines (eg, IL-6, IFN-gamma, G-CSF) was observed on off-pump surgery to a similar extent but with delayed kinetics. A total of 45 of 4868 transcripts were identified to be significantly altered as a result of initiation of CPB. Systematic analysis of transcriptional activation by CPB revealed primarily genes involved in inflammation-related cell-cell communication (such as L-selectin or intercellular adhesion molecule-2) and signaling (such as IL-1, IL-8, or IL-18 receptors and toll-like receptors 4, 5, and 6), thus confirming a "primed" phenotype of circulating peripheral blood mononuclear cells. CONCLUSIONS: Gene array and multiplex protein analysis, only in concert, can illuminate the molecular mechanisms responsible for systemic sequelae of CPB and indicate that circulating leukocytes overexpress adhesion and signaling factors after contact with CPB, which potentially facilitates their trapping, eg, in the lungs and may promote a subsequent tissue-associated inflammatory response.

University of Wisconsin versus St. Thomas' Hospital solution for human donor heart preservation.

Prolongation of the safe period of ischemia of the heart is an efficient way to overcome donor organ shortage, as demonstrated in renal and hepatic transplantation. We present the results of a prospective, randomized study comparing preservation with University of Wisconsin solution (UWS) versus St. Thomas' Hospital solution (STS) in clinical heart transplantation. A total of 39 patients were enrolled in the study (n = 20 for UWS and n = 19 for STS). Hemodynamic, electron microscopic, and biochemical evaluation did not reveal any significant differences in postoperative myocardial performance. Only the number of intraoperative defibrillations (0.82 for UWS versus 1.7 for STS) and the rhythm stability after reperfusion (13/20 UWS hearts versus 6/19 STS hearts in sinus rhythm) were significantly different. Heart preservation with UWS and STS appears to be of comparable efficacy at mean ischemic times of less than 4 hours.

Redo- extirpation of a cardiac leiomyosarcoma to avoid transplantation.

Cardiac leiomyosarcoma is a very rare entity that is found in less than 0.2 % of all cardiac tumors. At the time of primary diagnosis, it often shows advanced local invasion or may even be metastasized. Thus, complete resection can not easily be achieved. Cardiac transplantation has been reported as a therapeutic option. Here, we report on a case of a leiomyosarcoma reoccurrence arising 2 years after initial surgery. We performed a radical redo-extirpation without the necessity of transplantation.

Myocardial preservation with the UW solution. First European results in clinical heart transplantation.

In recent years, there is a growing body of evidence that the University of Wisconsin (UW) solution offers many advantages in organ preservation with regard to preservation quality and time. We, therefore, conducted the first European prospective, randomized, clinical trial comparing myocardial performance after preservation with UW and St. Thomas Hospital (ST) solution. Preliminary results indicated superior heart function after preservation with UW solution.

Outcome of patients after cardiac surgery transferred to other hospitals following prolonged intensive care stay.

BACKGROUND: The steady rise in complex cardiac procedures as well as the increase in comorbidity often result in a prolonged intensive care unit (ICU) stay. As a consequence, considerable numbers of patients have to be transferred to other hospitals so that the primary institution can maintain its capacity. The purpose of this study was to investigate the outcome of these patients. METHODS: 1,175 consecutive patients underwent various open heart procedures. 115 patients (9.8 %) requiring prolonged ICU treatment were retrospectively analyzed. 74 patients (EuroSCORE 8.1) underwent transferral to either rehabilitation units with ventilation capacity, multidisciplinary ICUs, or cardiac ICUs. 41 patients (EuroSCORE 7.9) remained in our hospital. Morbidity, mortality, and clinical condition were assessed and compared. RESULTS: Transferred patients exhibited an overall mortality of 38 % compared to only 17 % in patients who remained. Mortality was 81 % in rehabilitation units, 30 % in multidisciplinary ICUs, and 16 % in cardiac ICUs. 66 % of the survivors among the transferred patients showed significantly impaired clinical condition (NYHA III-IV) compared to 33 % who showed a good postoperative condition (NYHA I-II). The patients who remained exhibited 44 % NYHA III-IV and 56 % NYHA I-II. CONCLUSION: Transferral of patients after prolonged intensive care stay to external hospitals carries significant risks for early death and impaired outcome. However, transferral to cardiac ICUs appears to be an adequate option. Further studies may identify potential subgroups of patients who do not benefit from transferral.