Zeitplan Slot

Establishment of a standardized, immunocompetent in vitro 3D wound model incorporating hypoxia and artificial infection for the testing and investigation of regenerative processes.

The model consists of a collagen-based dermal component containing adult fibroblasts (NHDF) and monocytes (THP-1), as well as an epidermis composed of keratinocytes (HaCaT). Within the model, monocytes differentiate into M0 macrophages (precursor), followed by a controllable polarization of the macrophages into specific M1 (proinflammatory) or M2 (antiinflammatory) phenotypes using IFN-g/ LPS for M1 and IL-4/IL-13 for M2. Wounding is performed using a self-developed static device “WuBo-20” composed of commercially available components, allowing for standardized control over wound depth and positioning. The inflammatory milieu of a chronic wound is simulated by artificial (LPS, IFN-g) and hypoxic (3% O₂) stimuli. HE-stainings, immunohistological (CD86/CD206) and secretory profile (CCL-2, VEGF) analyses are used to assess macrophage polarization and activity.

The cells were successfully integrated into a cocultured dermal matrix, differentiated and cultivated for extended periods (21 days). Keratinocytes were successfully seeded onto the dermis. Using WuBo-20, variances in wound depth and position could be minimized. WuBo-20 is reusable, sterilizable by UV light and autoclaving. Analysis of the macrophage secretory profile within the wound model showed consistent results: increased proinflammatory CCL-2 secretion and CD86/CD206-Ratio in M1-models compared to the proregenerative M2-models. Hypoxic and inflammatory conditions delayed wound regeneration and promoted a transient pro-inflammatory response, characterized by elevated CD86/CD206 ratios and increased expression of pro-inflammatory markers such as CCL-2 and stagnated growth factors such as VEGF compared to normoxia.

A standardized 3D human wound model based on commercially available cell lines was successfully established. The model offers ethical, economic and reproducible advantages over animal models and existing in vitro systems, while recapitulating key features of hypoxic chronic wounds, including inflammation and impaired regeneration. It provides a clinically relevant platform for studying wound pathophysiology and evaluating novel therapeutics.

Assess how and to what extent hypoxia and infection can be modeled in-vitro, with the ultimate goal of establishing a realistic in-vitro wound model.

The model consists of a collagen-based dermal component containing fibroblasts (NHDF) and monocytes (THP-1), as well as a layered keratinocyte layer (HaCaT) to generate an epidermal layer. This enables controlled polarization (IFN-gamma/LPS for M1; IL-4/IL-13 for M2) of the macrophages within the model into the M1 (pro-inflammatory) or M2 (anti-inflammatory) phenotype. Wounding is performed using a custom-developed static apparatus that standardizes wounding depth and position. To test the hypoxic stimulus, atmospheric oxygen concentrations ranging from 0.2% to 3% were tested on the model. The goal was to determine the lowest O₂ level suitable for establishing a stable hypoxic wound model. In addition, infectious-inflammatory triggers such as IFN-gamma (20 ng/ml) and LPS (100 ng/ml) were applied either daily or every second/third day to identify the interval at which the infected models remain stable and exhibit a corresponding response. In this context, IFN-gamma and LPS represent artificial infection stimulators intended to mimic the environment of an inflammatory wound.

Under 0.2% O₂, models with the M2 phenotype survive for an extended period (>20 days). Models with the M1 phenotype, however, do not survive even 23 hours under 1% O₂, as the model disintegrates due to a self-amplifying inflammatory response. At 3% O₂, models with all macrophage phenotypes remain stable. A daily infectious stimulus of 20 ng/ml IFN-gamma and 100 ng/ml LPS causes the models with M1-polarized macrophages to disintegrate starting on day 16. With an infectious stimulus every 2–3 days, however, the models do not disintegrate under IFN-gamma and LPS stimulation and exhibit an adequate response to the set trigger.

Our study shows that for the immunocompetent 3D in vitro wound model, the minimum oxygen saturation level required is 3% and the infection interval is 2–3 days, in order to generate stable wound models that accurately replicate a chronic wound environment. This minimal hypoxia also mimics the moderate physiological hypoxia that occurs clinically, meaning that the model now reflects clinical reality and offer advantages for the preclinical testing of new therapeutics in the management of chronically hypoxic infected wounds.

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with vascular graft or endograft infection (VGEI), in succession to the 2020 version, with the aim of assisting physicians and patients in selecting the best management strategy.

The guidelines are based on scientific evidence complemented with expert opinion. By summarising and evaluating the best available evidence, recommendations for the evaluation and management of patients with VGEI have been formulated. The recommendations are graded according to the ESVS grading system, where
the strength (class) of each recommendation is graded from I to III, and the level of evidence from A to C.

Eighty-one recommendations have been issued across the following main topics: definitions, diagnosis, multidisciplinary team management, antimicrobial therapy, management of intracavity or extracavity VGEI, and follow up. A chapter addresses the concept of shared decision making, with supporting information for patients.
A final chapter addresses unresolved issues.

These ESVS clinical practice guidelines provide comprehensive, up to date advice to clinicians and patients on the management of VGEI.

To evaluate the impact of pre-operative aorto-iliac anatomical characteristics on technical success, iliac vessel patency, endoleaks, and reintervention following iliac branched device (IBD) E-liac (Artivion) implantation for aorto-iliac aneurysmal disease.

This retrospective two-center cohort study included all consecutive patients undergoing endovascular repair with off-the shelf IBD E-liacTM (Artivion) between February 2011 and October 2024. Pre-operative computed tomography angiography (CTA) with three-dimensional centerline reconstruction (TeraRecon, Foster City, CA) was used to assess aorto-iliac anatomy. Primary endpoints were 30-day technical success, iliac vessel patency, type I/III endoleaks, and IBD/iliac vessel-related reintervention. Secondary endpoints included follow-up iliac vessel patency and endoleak I/III, overall iliac vessel reinterventions, and mortality. Time-to-event analysis was performed using Kaplan–Meier and multivariable Cox regression models.

A total of 216 patients (mean age 73.0 ± 7.2 years; 93.5% male) with 239 implanted IBDs were included. 213 (98.6%) procedures were elective. Thirty-day technical success was 98.7%. Thirty-day IBD/iliac vessel-related reintervention occurred in 2.5%, and iliac vessel occlusion in 2.5 %. Thirty-day endoleak rate (I/III) was 8.8 %. At a median follow-up of 33.3 months (IQR 16.6 – 66.8), IBD / iliac vessel-related reintervention occurred in 17.2% and overall reintervention in 18.5%. Cumulative incidence of IBD/iliac vessel-related reintervention was 5.8% at 12 months and 16.9% at 84 months. Follow-up IBD occlusion was 1.7%. Overall mortality was 25.5%, with 1.9% aortic-related mortality. On multivariable Cox regression analysis, maximum aortic aneurysm diameter (HR 1.038, 95% CI 1.014–1.063; p = 0.002), external iliac artery (EIA) tortuosity (HR 1.424, 95 % CI 1.031 – 1.968, p = .032) and number of bridging stents (HR 1.722, 95% CI 1.139–2.603; p = 0.010) independently predicted IBD / iliac vessel-related reintervention.

High technical success and durable mid-term outcomes can be expected independently of aorto-iliac anatomy in IBD implantation. Larger aortic aneurysm diameter, EIA tortuosity and increasing bridging stent number are associated with higher IBD/iliac vessel reintervention risk.

Carotid endarterectomy (CEA) is associated with postoperative cervical hematoma, a potentially life-threatening complication that may require surgical re-exploration. Although cervical drainage is frequently used to prevent hematoma formation, the European Society for Vascular Surgery (ESVS) guidelines leave its use to the surgeon's discretion. This study evaluated the impact of cervical drainage on hemorrhagic and 30-day postoperative complications following CEA.

This retrospective single-center observational study included consecutive patients who underwent CEA between January 2020 and December 2024. The primary endpoint was reoperation for postoperative cervical hematoma within 30 days. Secondary endpoints included ipsilateral stroke, cranial nerve injury, surgical site infection, medical complications, and 30-day mortality. Continuous variables were analyzed using Student's t-test, and categorical variables using Fisher's exact or chi-square tests. Statistical significance was defined as p < 0.05.

A total of 153 CEAs were performed in 147 patients. Drainage was used in 118 procedures (77.1%) and omitted in 35 (22.9%). Baseline demographic and clinical characteristics were comparable between groups. Patch angioplasty was performed in 75.4% of patients with drainage and 91.4% without drainage. Reoperation for cervical hematoma occurred in five cases (3.3%) and did not differ significantly between patients without drainage (2.9%) and those with drainage (3.4%; p = 1.0). No significant differences were observed in ipsilateral stroke (2.5% vs. 5.7%; p = 0.322), cranial nerve injury (10.2% vs. 14.3%; p = 0.542), surgical site infection (2.9% vs. 0.8%; p = 0.406), medical complications, or 30-day mortality.

Routine cervical drainage after CEA was not associated with a reduction in postoperative hemorrhagic complications requiring reoperation or in other 30-day medico-surgical complications. These findings support a selective rather than routine use of drainage according to intraoperative judgment. However, the low number of hemorrhagic events may have limited the statistical power to detect small between-group differences. Larger prospective multicenter studies are warranted to confirm these findings.

Arteriovenous fistulas (AVFs) are the preferred vascular access for long-term hemodialysis, whereas tunneled central venous catheters (TDCs) remain necessary in selected patients despite higher complication rates. Patient-reported preferences have received little attention. This study evaluated patients' subjective comparisons of AVFs and TDCs regarding comfort, limitations in daily life, body image, psychological burden, preoperative counselling, and overall access preference.

In this single-center questionnaire study, all chronic hemodialysis patients at the main site of our hospital were invited to participate. Self-reported vascular access history was verified using medical records. Patients indicated which vascular access they perceived as superior in the domains and evaluated preoperative counselling. Patients with experience of both access types provided direct comparisons, whereas those with only one access type reported their perceived preference for the alternative access. Data were analyzed descriptively.

Of 43 patients, 6 were excluded because of insufficient language proficiency. Of the remaining 37 patients, 23 returned the questionnaire and 21 completed it. Nine patients had only a TDC, 6 only an AVF, and 6 had experience with both access types. Among patients with both access types, most preferred the AVF (4/6), although the TDC was more often rated as more comfortable (5/6). Daily-life limitations and psychological well-being were largely comparable, while body image showed no clear preference. Patients with exclusive TDC experience predominantly preferred the TDC and rated is as more comfortable and less restrictive, whereas those with exclusive AVFs predominantly preferred the AVF and perceived advantages regarding body image and psychological well-being. Satisfaction with preoperative counselling was high across all groups.

Although limited by the small sample size and the partly hypothetical assessments from patients with experience of only one access type, the findings suggest an overall trend towards a preference for AVFs, whereas TDCs were predominantly perceived as more comfortable. These findings provide insights into the patient perspective on vascular access that may help inform preoperative counselling and shared decision-making alongside established clinical outcome data.

To compare complication profiles of Cimino (RCAVF) and snuffbox arteriovenous fistulas (SBAVF) for hemodialysis access. Despite differing by only 2 – 4 cm in anastomotic location, anatomical differences may influence access-related complications.

In this retrospective single-center cohort study, all distal radiocephalic AV fistulas created between January 2021 und December 2024 with 12-months follow-up were analyzed. Primary and assisted maturation, reintervention rate - and access-related complications requiring endovascular or surgical intervention were compared.

Sixty-one distal radiocephalic AV fistulas were created. Eight patients were excluded because of loss to follow-up, leaving 23 SBAVFs and 30 RCAVFs for analysis. Primary and assisted maturation rates were 52.2% and 73.9% for SBAVFs versus 63.3% and 83.3% for RCAVFs (p=0.57 and p=0.49 respectively).
15 reinterventions were performed in 12 SBAVF patients (52.2%) and 19 in 14 RCAVF patients (46.7%). The incidence of anastomotic stenosis requiring intervention (SBAVF 17.4%, RCAVF 20.0%), type II venous outflow stenosis (cannulation segment) (SBAVF 8.7%, RCAVF 0%), surgical revision for clinically relevant venous side branches (SBAVF 17.4%, RCAVF 6.7%) - and early (SBAVF 8.7%, RCAVF 3.3%) and late thrombosis (SBAVF 4.3%, RCAVF 3.3%) did not differ significantly between the groups. In contrast type I juxta-anastomotic venous stenosis occurred significantly more frequently in the RCAVF group than in the SBAVF group (40.0% versus 8.7%, p=0.003). Furthermore, steal syndrome occurred only after SBAVF creation (8.7% versus 0%, p=0.18).

Although maturation and overall reintervention rates did not differ significantly, RCAVFs and SBAVFs demonstrated distinct complication profiles. RCAVFs showed a significantly higher incidence of type I juxta-anastomotic venous stenosis, whereas steal syndrome was observed exclusively after SBAVF creation. These findings suggest that anatomical differences between these distal fistula configurations influence the pattern of access-related complications.

To compare the outcome of snuffbox arteriovenous fistulas (SBAVFs) and Cimino fistulas (RCAVFs) for hemodialysis access to evaluate whether a SBAVF-first approach is justified.

One-year outcomes of SBAVFs und RCAVFs (2021 – 2024) created for hemodialysis were analyzed retrospectively. Endpoints included maturation rates (functioning dialysis or ultrasound results for preemptive cases), reinterventions (specifically proximalizations), and ischemic complications. Access site selection was based on preoperative ultrasound vessel diameter assessment.

A total of 61 distal radio-cephalic fistulas were created (25 SBAVFs, 36 RCAVFs). Eight patients were lost to follow-up due to unrelated death or transfer to external care.
In the SBAVF group (n=23), primary maturation was 52.2% (12/23) and assisted 73.9% (17/23). 15 reinterventions were required in 12 patients (52.2%), including 12 surgical revisions — eight of which were proximalizations (34.8%)—and three percutaneous transluminal angioplasties (PTA). Notably, two cases of steal syndrome (8.7 %) were identified.
In the RCAVF group (n=30), primary and assisted maturation rates were 63.3% (19/30) and 83.3% (25/30) respectively. 19 reinterventions were needed in 14 patients (46.7%) including five proximalizations (16.7%) and 11 PTAs. No ischemic complications were observed.

Compared with RCAVFs, SBAVFs showed slightly lower maturation rates and required nearly twice as many proximalization procedures. Furthermore, steal syndrome was observed exclusively in the snuffbox fistula group. Consequently, a SBAVF-first approach may not be justified.