Jan Spillner

Objectives: Acute intermediate–high-risk pulmonary embolism (PE) is associated with right-ventricular (RV) dysfunction, biomarker elevation, and risk of early clinical deterioration. Ultrasound-assisted catheter-directed thrombolysis (USAT) using the Eko Sonic Endovascular System (EKOS) system is increasingly used in selected patients; however, real-world data on physiological response and clinically relevant in-hospital outcomes remain limited. Methods: We conducted a retrospective single-centre analysis of 128 consecutive patients with acute intermediate–high-risk PE treated with EKOS-guided USAT within a structured Pulmonary Embolism Response Team (PERT) pathway between August 2017 and December 2023. Changes in RV/LV ratio, B-type natriuretic peptide (BNP), and cardiac troponin before and after intervention were assessed. A composite end-point of death, extracorporeal membrane oxygenation (ECMO), renal replacement therapy, or invasive mechanical ventilation captured clinically meaningful deterioration. Multivariable logistic regression identified determinants of the composite end-point. Results: RV/LV ratio and biomarkers improved significantly after intervention. Median RV/LV ratio decreased from 1.6 to 1.0, and BNP declined from 2365 to 877 pg/mL (both P < .001). Clinically meaningful in-hospital deterioration requiring escalation of organ support occurred in a subset of patients and was predominantly associated with baseline disease severity. Short-term survival remained favourable (60-day probability 96.9%). Conclusions: In this real-world, PERT-guided cohort, EKOS was associated with rapid physiological improvement and favourable short-term survival in patients with intermediate–high-risk PE. These findings should be interpreted as descriptive single-centre experience.

Introduction: Pulmonary artery (PA) cannulation is emerging as a method for concurrent cardiac and respiratory failure, but limited data exists on how cannula positioning, particularly cannula tip angle, affects perfusion symmetry. Due to varying pulmonary bifurcation geometry between patients, ensuring even distribution of oxygen-saturated blood becomes critical. This computational fluid dynamics (CFD) study investigated the effects of cannula positioning and angles on oxygen delivery within the PA using 6 different configurations. Method: An idealized PA geometry based on a CT scan was constructed including the 6 different cannula configurations: two straight (short and long) and four angled (5° and 10° toward either pulmonary branch). Simulations assumed laminar, steady-state flow at 6 L/min total (50% ECMO contribution). Oxygen transport was modeled as a passive scalar with 75% saturation from the heart and 100% from the cannula. Perfusion symmetry was quantified using the absolute difference in mean oxygen saturation (ΔSaO ₂ ) and partial pressure (ΔpO ₂ ) between the right (RPA) and left pulmonary arteries (LPA). Results: Cannula positioning and angulation influences oxygen distribution within the PA. Straight-tipped cannulas favored LPA-sided flow due to the natural geometry of the pulmonary artery (ΔSaO ₂ = 12.9–15.1%). A 5° RPA directed angulation achieved the most symmetric distribution (ΔSaO ₂ = 9.2%, ΔpO ₂ = 14.2 mmHg), whereas greater or opposite angulations increased flow asymmetry. Conclusion: Minor cannula tip angulation, specifically 5° deflection towards the RPA, enhances bilateral PA oxygenation without increasing ECMO flow, providing a simple yet effective strategy for optimizing pulmonary ECMO perfusion.

Purpose: Medical societies around the globe are searching for ways to decrease the environmental impacts of patient care. This pilot project aims to identify potentials for more sustainability in clinical routine by investigating the resource consumption of thoracic surgery patients. Methods: This single-centre, observational, prospective pilot project was conducted at the RWTH Aachen University Hospital, Germany, from May 2023 to August 2023. Five patients with planned video-assisted-thoracoscopic surgery for removal of (suspected) lung cancer were included and followed throughout their treatment at the hospital. We recorded resource consumption for their direct care and investigated the share of disposable and reusable products and the packaging of disposable products. Additionally, we conducted a PubMed literature search on available life cycle assessments of the utilised products and investigated manufacturers’ online information on sustainability aspects of their products. Results: An average of 1254 disposable (75%) and reusable (25%) products were used per patient throughout their hospital journey. Most disposable products’ packaging contained plastic. We identified 30 publications that reported life cycle assessments. Manufacturers provided information on sustainability aspects for 10% of the products utilised. Conclusions: In-hospital patient care is resource intensive. Disposable products outnumbered reusable products at every stage of the patient’s journey and were mostly packaged in materials containing plastic. For the majority of products, no information concerning their environmental impact was accessible hampering informed purchasing choices by clinicians. Further efforts are essential to make environmental data available, leverage circular-economy systems, and ultimately decrease the environmental impacts of the healthcare sector.

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.

Introduction: In peripheral percutaneous (VA) extracorporeal membrane oxygenation (ECMO) procedures the femoral arteries perfusion route has inherent disadvantages regarding poor upper body perfusion due to watershed. With the advent of new long flexible cannulas an advancement of the tip up to the ascending aorta has become feasible. To investigate the impact of such long endoluminal cannulas on upper body perfusion, a Computational Fluid Dynamics (CFD) study was performed considering different support levels and three cannula positions. Methods: An idealized literature-based- and a real patient proximal aortic geometry including an endoluminal cannula were constructed. The blood flow was considered continuous. Oxygen saturation was set to 80% for the blood coming from the heart and to 100% for the blood leaving the cannula. 50% and 90% venoarterial support levels from the total blood flow rate of 6 l/min were investigated for three different positions of the cannula in the aortic arch. Results: For both geometries, the placement of the cannula in the ascending aorta led to a superior oxygenation of all aortic blood vessels except for the left coronary artery. Cannula placements at the aortic arch and descending aorta could support supra-aortic arteries, but not the coronary arteries. All positions were able to support all branches with saturated blood at 90% flow volume. Conclusions: In accordance with clinical observations CFD analysis reveals, that retrograde advancement of a long endoluminal cannula can considerably improve the oxygenation of the upper body and lead to oxygen saturation distributions similar to those of a central cannulation.

Long‐Term Cardiac Neurostimulation. Introduction: The right inferior ganglionated plexus (RIGP) selectively innervates the atrioventricular node. Temporary electrical stimulation of this plexus reduces the ventricular rate during atrial fibrillation (AF). We sought to assess the feasibility of chronic parasympathetic stimulation for ventricular rate control during AF with a nonthoracotomy intracardiac neurostimulation approach. Methods and Results: In 9 mongrel dogs, the small endocardial area inside the right atrium, which overlies the RIGP, was identified by 20 Hz stimulation over a guiding catheter with integrated electrodes. Once identified, an active‐fixation lead was implanted. The lead was connected to a subcutaneous neurostimulator. An additional dual‐chamber pacemaker was implanted for AF induction by rapid atrial pacing and ventricular rate monitoring. Continuous neurostimulation was delivered for 1–2 years to decrease the ventricular rate during AF to a range of 100–140 bpm. Implantation of a neurostimulation lead was achieved within 37 ± 12 min. The latency of the negative dromotropic response after on/offset or modulation of neurostimulation was Conclusion: Chronic parasympathetic stimulation can be achieved via a cardiac neurostimulator. The approach is safe, effective, and well tolerated in the long term. The atrioventricular nodal selectivity and the opportunity to adjust the negative dromotropic effect within seconds may represent an advantage over pharmacological rate control. (J Cardiovasc Electrophysiol, Vol. 21, pp. 193‐199, February 2010)

A novel magnetic navigation system allows remote steering of guidewires and catheters. This system may be used for left ventricular lead placement for cardiac resynchronization therapy (CRT). We sought to evaluate the feasibility and safety of magnetic guidewire navigation for CRT procedures. 123 consecutive patients underwent CRT implantation/revision procedures (including pacemaker upgrades in n=22 and left ventricular lead placement after dislocation in n=4 patients). Left ventricular lead placement in a coronary sinus side branch was performed either conventionally or using magnetic navigation. The magnetic navigation system (Niobe) consists of two permanent magnets creating a steerable magnetic field. Guidewires with integrated magnets align to the magnetic field and were used for over-the-wire implantation of pacemaker leads in the coronary sinus. Patients were assigned to conventional (n=93) or magnetic (n=30) navigation according to room availability. Venography of the coronary venous system was performed to select a target vessel for lead implantation. Guidewire access to the target vessel was achieved in 100% using magnetic navigation compared to 87% with the conventional approach (P < 0.05). Implantation success rates, total procedure and fluoroscopy times did not differ significantly between groups. No periprocedural death and no intraoperative device dysfunction occurred in either group.The magnetic guidewire ruptured in one patient. Left ventricular lead placement using magnetic guidewire navigation to engage the desired coronary sinus side branch can be successfully performed for CRT.