Introduction: Veno‐venous extracorporeal membrane oxygenation (V‐V ECMO) is increasingly used in the treatment of severe respiratory failure. Despite a significant increase in the worldwide use of extracorporeal lung assist devices recirculation remains a common complication and is associated with a reduced effectiveness of ECMO support and increased hemolysis. In this observational study we aimed to investigate the impact of cannula configuration and extracorporeal flow on recirculation. Materials and Methods: An observational retrospective study was performed, which included all patients, who received V‐V ECMO and recirculation measurements at the University Medical Center Freiburg between August 2021 and June 2023. Recirculation and extracorporeal flow were determined using ultrasonic indicator dilution technology. Patients were divided into subgroups according to their type of cannulation (dual lumen single‐site vs. bifemoral vs. femoro‐jugular). Results: A total of 215 recirculation measurements in 47 patients were performed. Dual lumen single‐site cannulation was associated with significantly lower recirculation rates (8.7% [0.0; 12.0]) compared to single lumen dual‐site cannulation (femoro‐jugular: 17.6% [0.0; 25.8]; bifemoral: 27.9% ± 13.4%). In addition, a positive linear correlation was observed between extracorporeal flow and recirculation in all subgroups. Recirculation increased significantly with rising extracorporeal flow in all subgroups. Conclusion: Recirculation is a common complication in V‐V ECMO and can lead to a reduction of ECMO effectiveness. Particular attention should be paid to optimal positioning of the cannulas in patients with more than one cannula. The ultrasonic indicator dilution method is a simple and quick method for measuring recirculation in V‐V ECMO and can be used at an early stage if effectiveness decreases.

Background: Our aim was to investigate outcomes and long-term survival in male and female patients after frozen elephant trunk (FET) total arch replacement. Methods: Between March 2013 and January 2023, 362 patients underwent aortic arch replacement via the FET technique. We compared patient characteristics and intra- and postoperative data between male and female patients. Results: Male patients were significantly younger (p = 0.012) but revealed a higher incidence of coronary artery disease (p = 0.008) and preoperative dialysis (p = 0.017). More male patients presented with type A aortic dissections (p = 0.042) while more female patients had aortic aneurysms (p = 0.025). The aortic root was replaced in significantly more male patients (p = 0.013), resulting in significantly longer cardiopulmonary bypass duration (p < 0.001) and operative times (p < 0.001). There were no statistically significant differences in postoperative outcome parameters including in-hospital mortality (p = 0.346). However, new in-stent thrombus formation was significantly more frequent in female patients (p = 0.002). Age in years (odds ratio (OR): 1.026, p = 0.049), an acute pathology (OR: 1.941, p = 0.031) and preoperative dialyses (OR: 3.499, p = 0.010) were predictive for long-term mortality in our Cox regression model, sex (p = 0.466) was not. There was no statistical difference in overall survival (log rank: p = 0.425). Conclusions: Female patients are older but reveal fewer cardiovascular risk factors; aneurysms are more common in female than male patients. As female patients undergo concomitant surgical procedures less often, their operative times are shorter. While survival and outcomes were similar, female patients suffered from postoperative new in-stent thrombus formation significantly more often.

Background and Objectives: The aim of this study was to analyze the influence of mass transfusion on the postoperative outcome and survival in patients presenting with acute Type A aortic dissection. Materials and Methods: Between 2002 and 2020, a total of 505 patients were surgically treated for an acute Type A aortic dissection. Mass transfusion was defined as the peri- and postoperative replacement by transfusion of 10 units. Patient characteristics and outcomes were analyzed and compared between patients with and without mass transfusion. Results: Mass transfusion occurred in 105 patients (20%). The incidences of symptomatic coronary malperfusion (p = 0.017) and tamponade (p = 0.043) were higher in patients with mass transfusion. There was no statistically significant difference in the distal extension of the aortic dissection between the two groups. A valved conduit was significantly more common in patients with mass transfusion (p = 0.007), while the distal aortic repair was similar between the two groups. Cardiopulmonary bypass time (p < 0.001), cross clamp time (p < 0.001) and in-hospital mortality were significantly higher in patients with mass transfusion (p < 0.001), but the survival after discharge (landmark-analysis) showed equal survival between patients with and without mass transfusion (log rank: p = 0.4). Mass transfusion was predictive of in-hospital mortality (OR: 3.308, p < 0.001) but not for survival after discharge (OR: 1.205, p = 0.661). Conclusions: Mass transfusion is necessary in many patients with acute Type A aortic dissection. These patients present sicker and require longer surgery. However, mass transfusion does not influence survival after discharge.

Background: The aim of this retrospective cohort study was to analyze the outcomes and the need for reinterventions following branched iliac artery repair using the Zenith^® Branch Endovascular Iliac Bifurcation (ZBIS; Cook Medical Europe LTD, Limerick, Ireland) graft. Methods: Patient characteristics and follow-up data on 63 patients following branched iliac artery repair using the ZBIS device were evaluated and compared between patients with and without iliac reinterventions. A competing risk regression model was analyzed to identify independent predictors of reinterventions, and to predict the reintervention risk. Results: ZBIS implantation’s technical success rate was 100%, and we observed no in-hospital mortality. Internal iliac artery patency was 93% during a median [first quartile, third quartile] follow-up of 19 [5, 39] months. Thirty-two iliac reinterventions were performed in 23 patients (37%) after a mean time of 3.0 months (IQR: 0.4–6.8) (time to first reintervention). Endoleaks type I and II were the most common indication for reinterventions (n=14, 61%). The internal iliac artery’s diameter [subdistribution hazard ratio (sHR): 1.046; P=0.0015] and a prior abdominal aortic intervention (sHR: 0.3331; P=0.0370) were identified as significant variables in the competing risk regression model for a reintervention. The risk for reintervention was 33% (95% CI: 20–46%), and 46% (95% CI: 28–63%) after 12 and 36 months, respectively. Conclusions: Endovascular repair of degenerative iliac artery aneurysms with Zenith Branch Iliac Bifurcation device is a feasible and safe option. Perioperative morbidity and mortality are low with good graft patency rates. The risk for secondary iliac artery interventions is considerable and highlights the need for patients with iliac disease to undergo continuous follow-up in a dedicated vascular center.