The Self-Expandable Impella CP (ECP) as a Mechanical Resuscitation Device.

The survival rate of cardiac arrest (CA) can be improved by utilizing percutaneous left ventricular assist devices (pLVADs) instead of conventional chest compressions. However, existing pLVADs require complex fluoroscopy-guided placement along a guidewire and suffer from limited blood flow due to their cross-sectional area. The recently developed self-expandable Impella CP (ECP) pLVAD addresses these limitations by enabling guidewire-free placement and increasing the pump cross-sectional area. This study evaluates the feasibility of resuscitation using the Impella ECP in a swine CA model. Eleven anesthetized pigs (73.8 ± 1.7 kg) underwent electrically induced CA, were left untreated for 5 min and then received pLVAD insertion and activation. Vasopressors were administered and defibrillations were attempted. Five hours after the return of spontaneous circulation (ROSC), the pLVAD was removed, and animals were monitored for an additional hour. Hemodynamics were assessed and myocardial function was evaluated using echocardiography. Successful guidewire-free pLVAD placement was achieved in all animals. Resuscitation was successful in 75% of cases, with 3.5 ± 2.0 defibrillations and 1.8 ± 0.4 mg norepinephrine used per ROSC. Hemodynamics remained stable post-device removal, with no adverse effects or aortic valve damage observed. The Impella ECP facilitated rapid guidewire-free pLVAD placement in fibrillating hearts, enabling successful resuscitation. These findings support a broader clinical adoption of pLVADs, particularly the Impella ECP, for CA.

Factors Associated with Early Mortality in Acute Type A Aortic Dissection-A Single-Centre Experience.

BACKGROUND: Acute aortic dissection type A (AADA) is a surgical emergency with relevant mortality and morbidity despite improvements in current management protocols. Identifying patients at risk of a fatal outcome and controlling the factors associated with mortality remain of paramount importance. METHODS: In this retrospective observational study, we reviewed the medical records of 117 patients with AADA, who were referred to our centre and operated on between 2005 and 2021. Preoperative, intraoperative, and postoperative variables were analysed and tested for their correlation with in-hospital mortality. RESULTS: The overall survival rate was 83%. Preoperatively, factors associated with mortality were age (p = 0.02), chronic hypertension (p = 0.02), any grade of aortic valve stenosis in the patient's medical history (p = 0.03), atrial fibrillation (p = 0.04), and oral anticoagulation (p = 0.04). Non-survivors had significantly longer operative times (p = 0.002). During the postoperative phase, mortality was strongly associated with acute kidney injury (AKI) (p < 0.001), acute heart failure (p < 0.001), stroke (p = 0.02), focal neurological deficits (p = 0.02), and sepsis (p = 0.001). In the multivariate regression analysis, the onset of postoperative focal neurological deficits was the best predictor of a fatal outcome after adjusting for ARDS (odds ratio: 5.8, 95%-CI: 1.2-41.7, p = 0.04). CONCLUSIONS: In this retrospective analysis, atrial fibrillation, oral anticoagulation, hypertension, and age were significantly correlated with mortality. Postoperatively, acute kidney injury, acute heart failure, sepsis, and focal neurological deficits were correlated with in-hospital mortality, and focal neurological deficit has been identified as a significant predictor of fatal outcomes. Early detection and interdisciplinary management of at-risk patients remain crucial throughout the postoperative phase.

In vitro evaluation of the performance of an oxygenator depending on the non-standard gas content of the inlet blood with special regard on CO2 elimination.

INTRODUCTION: The performance of an oxygenator, as found in literature, is evaluated according to protocols that define standard values of the gas content in the inlet blood. However, when dealing with simulations of lung insufficiency, a more extensive evaluation is needed. This work aims to investigate and assess the gas exchange performance of an oxygenator for different input values of gas content in blood. METHODS: Three commercially available oxygenators with different membrane surfaces were investigated in a mock loop for three blood flow rates (0.5l/min, 1l/min, and 5l/min) and two gas-to-blood ratios (1:1, and 15:1). The initial CO2 and O2 partial pressures (pCO2 and pO2) in blood were set to ≥ 100 mmHg and ≤10 mmHg, respectively. For each ratio, the efficiency, defined as the ratio between the difference of pressure inlet and outlet and the inlet pCO2 (pCO2(i)), was calculated. RESULTS: The CO2 elimination in an oxygenator was higher for higher pCO2(i). While for a pCO2(i) of 100 mmHg, an oxygenator eliminated 80 mmHg, the same oxygenator at the same conditions eliminated 5 mmHg CO2 when pCO2(i) was 10 mmHg. The efficiency of the oxygenator decreased from 76,9% to 49,5%. For simulation reasons, the relation between the pCO2(i) and outlet (pCO2(o)) for each oxygenator at different blood and gas flows, was described as an exponential formula. CONCLUSION: The performance of an oxygenator in terms of CO2 elimination depends not only on the blood and gas flow, but also on the initial pCO2 value. This dependence is crucial for simulation studies in the future.

Oxygenation performance assessment of an artificial lung in different central anatomic configurations.

OBJECTIVES: Aim of this work was to characterize possible central anatomical configurations in which a future artificial lung (AL) could be connected, in terms of oxygenation performance. METHODS: Pulmonary and systemic circulations were simulated using a numerical and an in vitro approach. The in vitro simulation was carried out in a mock loop in three phases: (1) normal lung, (2) pulmonary shunt (50% and 100%), and (3) oxygenator support in three anatomical configurations: right atrium-pulmonary artery (RA-PA), pulmonary artery-left atrium (PA-LA), and aorta-left atrium (Ao-LA). The numerical simulation was performed for the oxygenator support phase. The oxygen saturation (SO2) of the arterial blood was plotted over time for two percentages of pulmonary shunt and three blood flow rates through the oxygenator. RESULTS: During the pulmonary shunt phase, SO2 reached a steady state value (of 68% for a 50% shunt and of nearly 0% for a 100% shunt) 20 min after the shunt was set. During the oxygenator support phase, physiological values of SO2 were reached for RA-PA and PA-LA, in case of a 50% pulmonary shunt. For the same conditions, Ao-LA could reach a maximum SO2 of nearly 60%. Numerical results were congruous to the in vitro simulation ones. CONCLUSIONS: Both in vitro and numerical simulations were able to properly characterize oxygenation properties of a future AL depending on its placement. Different anatomical configurations perform differently in terms of oxygenation. Right to right and right to left connections perform better than left to left ones.

Urea-Creatinine Ratio (UCR) After Aneurysmal Subarachnoid Hemorrhage: Association of Protein Catabolism with Complication Rate and Outcome.

OBJECTIVE: The urea-creatinine ratio (UCR) has been proposed as potential biomarker for critical illness-associated catabolism. Its role in the context of aneurysmal subarachnoid hemorrhage (aSAH) remains to be elucidated, which was the aim of the present study. METHODS: We enrolled 66 patients with aSAH with normal renal function and 36 patients undergoing elective cardiac surgery as a control group for the effects of surgery. In patients with aSAH, the predictive or diagnostic value of early (day 0-2) and critical (day 5-7) UCRs was assessed with regard to delayed cerebral ischemia (DCI), DCI-related infarction, and clinical outcome after 12 months. RESULTS: Preoperatively, UCR was similar both groups. Within 2 days postoperatively, UCRs increased significantly in patients in the elective cardiac surgery group (P < 0.001) but decreased back to baseline on day 5-7 (P = 0.245), whereas UCRs in patients with aSAH increased to significantly greater levels on day 5-7 (P = 0.028). Greater early or critical UCRs were associated with poor clinical outcomes (P = 0.015) or DCI (P = 0.011), DCI-related infarction (P = 0.006), and poor clinical outcomes (P < 0.001) respectively. In multivariate analysis, there was an independent association between greater early UCRs and poor clinical outcomes (P = 0.026). CONCLUSIONS: In this exploratory study of UCR in the context of aSAH, greater early values were predictive for a poor clinical outcome after 12 months, whereas greater critical values were associated with DCI, DCI-related infarctions, and poor clinical outcomes. The clinical implications as well as the pathophysiologic relevance of protein catabolism should be explored further in the context of aSAH.

A New Percutaneous Approach to Treat Combined Right Ventricular and Respiratory Failure: The "Aachen Cannula".

INTRODUCTION: Right ventricular failure (RVF) on its own is a life-threatening condition. Often it manifests as a two-organ failure in the final phase of several lung diseases. Mechanical circulatory support is a proven treatment of RVF but remains challenging. Our objective is to develop a novel, simplified, and minimally invasive cannula approach to treat both RVF and respiratory failure. METHODS: We conceptualized a dual lumen cannula approach to allow oxygenated right-to-left shunting at an atrial level to decompress right-sided circulation. A minimally invasive approach through percutaneous, transjugular insertion and transseptal placement should enable patients to be non-sedated and even ambulatory. In an iterative design, pre-prototyping, prototyping, and anatomic fitting process, such a cannula was generated and tested in both cadaveric and fluid dynamic studies. RESULTS: After various modifications and improvements, a 27-Fr 255-mm-long double-lumen cannula with an inner line (oxygenated blood return to patient into the left atrium) of 18 Fr and an inflatable balloon (with a volume of approximately 1 mL) at the outflow tip was produced - one version with a straight head and another one with a curved head. In our anatomic studies, the "Aachen Cannula" allowed an easy transjugular introduction and advancement into the right atrium by Seldinger technique. Transseptal placement was achieved by puncture (Brockenbrough needle) in combination with dilatation and was then secured in place with the stabilizing balloon, even under slight tension. The cannula prototype enabled a flow of up to 3.5 L/min, at which common pressure drops were observed. CONCLUSION: In conclusion, we successfully conceptualized, designed, and verified a minimally invasive one-cannula approach for the treatment of either isolated right heart failure and even combined RVF and respiratory failure through our transseptal Aachen Cannula. This concept may also be carried out in ambulatory conditions. Moreover, this approach completely avoids recirculation issues and ensures reliable oxygenated coronary as well as cerebral perfusion.

The flutter-by effect: a comprehensive study of the fluttering cusps of the Perceval heart valve prosthesis.

OBJECTIVES: Sutureless aortic valve prostheses are gaining popularity due to the substantial reduction in cross-clamp time. In this study, we report our observations on the cusp-fluttering phenomenon of the Perceval bioprosthesis (LivaNova, London, UK) using a combination of technical and medical perspectives. METHODS: Between August 2014 and December 2016, a total of 108 patients (69% women) with a mean age of 78 years had aortic valve replacement using the Perceval bioprosthesis (34 combined procedures). All patients underwent transoesophageal echocardiography (TOE) intraoperatively. TOE was performed postoperatively to detect paravalvular leakage and to measure gradients, acceleration time, Doppler velocity indices (Vmax and LVOT/Vmax AV) and effective orifice area indices. In addition, a TOE examination was performed in 21 patients postoperatively. Data were collected retrospectively from our hospital database. RESULTS: The retrospective evaluation of the intraoperative TOE examinations revealed consistent fluttering in all patients with the Perceval bioprosthesis. The echocardiographic postoperative measurements showed a mean effective orifice area index of 0.91 ± 0.12 cm2/m2. The overall mean pressure and peak pressure gradients were in a higher range (13.5 ± 5.1 mmHg and 25.5 ± 8.6 mmHg, respectively), whereas acceleration time (62.8 ± 16.4 ms) and Doppler velocity indices (0.43 ± 0.11) were within the normal range according to the American Society of Echocardiography or european association of echocardiography (EAE) guidelines. The 2-dimensional TOE in Motion Mode (M-Mode) that was performed in patients with elevated lactate dehydrogenase (LDH) levels revealed remarkable fluttering of the cusps of the Perceval bioprosthesis. CONCLUSIONS: In our study cohort, we observed the fluttering phenomenon in all patients who received the Perceval bioprosthesis, which was correlated with elevated LDH levels and higher pressure gradients.

Does percutaneous dilatational tracheostomy increase the incidence of sternal wound infection - a single center retrospective of 4100 cases.

BACKGROUND: The impact of percutaneous dilatational tracheostomy (PDT) on the development of post-median sternotomy wound infection (SWI) and mediastinitis is still controversial. We aimed to investigate the frequency of cross-infection and incidence of SWI after PDT. METHODS: In a retrospective design, out of a total of 4100 procedures, all patients who had undergone median sternotomy and postoperative PDT were included from January 2010 to May 2013. For comparison of the pathogens isolated from SWIs, data from all patients who developed an SWI without a PDT during the aforementioned period were also analyzed. Demographical, pre-, peri- and post-operative data were compared. Microbiologic analysis from cultures of sternal and tracheal wounds was performed. Day and duration of tracheostomy were correlated to SWI occurrence. RESULTS: Of the 265 patients who underwent a PDT, 25 (9.4 %) developed an SWI. In this cohort, identical pathogens were isolated from the tracheostomy and SWI in 36 % (9/25) of the patients. Of the pathogens isolated from the SWIs from the PDT + SWI group, 60 % were gram-positive bacteria, 20 % gram-negative bacteria and 20 % Candida spp. In the cross-infection group, the patients developed the following types of SWIs: 11.1 % CDC I, 55.6 % CDC II and 33.3 % mediastinitis (CDC III). The incidence of SWI in the group SWI + PDT was 9.4 % (9.4 % vs. 3.4 %, PDT + SWI and SWI w/oPDT , respectively, p = 0.0001). In group SWI w/oPDT , only 1.5 % (2/131 vs. 5/25; p = 0.001) Candida spp were isolated from SWI. The infection-related in-hospital mortality was high in groups PDT + SWI vs. SWI w/oPDT (20 % vs. 0 %, respectively; p = 0.0001). The statistical analysis did not demonstrate any correlation between time of performing PDT and occurrence of SWI. CONCLUSIONS: There was a high incidence of microbial cross-infection from the PDTs to the sternal wounds in our study. We did not detect any correlation between the time of performing PDT and occurrence of SWI. According to our data, PDT seems to increase the incidence of SWI, especially caused by Candida spp., after cardiac surgery, which results in a prolonged hospital stay. Therefore, early antifungal prophylaxis after a PDT might be reasonable in high-risk patients on long-term mechanical ventilation if there is an impending SWI.