The study aim was to evaluate a small low-field NMR (nuclear magnetic resonance) scanner, the NMR-MOUSE^®, for detecting changes in intestinal diffusion under different (patho-) physiological perfusion states. Laparotomy was performed on 8 female landrace pigs (body weight 70±6 kg) and the feeding vessels of several intestinal loops were dissected. Successively, the intestinal loops were examined using O2C (oxygen to see, LEA Medizintechnik GmbH, Giessen, Germany) for microcirculatory monitoring and the NMR-MOUSE^® for diffusion measurement (fast and slow components). On each loop the baseline measurement (physiological perfusion) was followed by one of the following main procedures: method 1 –ischemia; method 2 –flow reduction; method 3 –intraluminal glucose followed by ischemia; method 4 –intraluminal glucose followed by flow reduction. Additionally, standard perioperative monitoring (blood pressure, ECG, blood gas analyses) and histological assessment of intestinal biopsies was performed. There was no statistical overall time and method effect in the NMR-MOUSE measurement (fast component: p_time = 0.6368, p_method = 0.9766, slow component: p_time = 0.8216, p_method = 0.7863). Yet, the fast component of the NMR-MOUSE measurement showed contrary trends during ischemia (increase) versus flow reduction (decrease). The slow-to-fast diffusion ratio shifted slightly towards slow diffusion during flow reduction. The O2C measurement showed a significant decrease of oxygen saturation and microcirculatory blood flow during ischemia and flow reduction (p < .0001). The local microcirculatory blood amount (rHb) showed a significant mucosal increase (p_{Clamping(method 1)} = 0.0007, p_{Clamping(method 3)} = 0.0119), but a serosal decrease (p_{Clamping(method 1)} = 0.0119, p_{Clamping(method 3)} = 0.0078) during ischemia. The histopathological damage was significantly higher with increasing experimental duration and at the end of methods 3 and 4 (p < .0001,Fisher-test). Monitoring intestinal diffusion changes due to different perfusion states using the NMR-MOUSE is feasible under experimental conditions. Despite the lack of statistical significance, this technique reflects perfusion changes and therefore seems promising for the evaluation of different intestinal perfusion states in the future. Beforehand however, an optimization of this technology, including the optimization of the penetration depth, as well as further validation studies under physiological conditions and including older animals are required.

Summary: Background: The objective of the study was to analyze mid-term results of unselected patients treated with the TREO (Terumo Aortic, Florida, USA) device at six German hospital sites. Methods: A multicenter, retrospective analysis of patients treated within and outside instructions for use (IFU) from January 2017 to November 2020 was performed. Primary outcomes were technical success, mortality and endograft related complications according to IFU status. Secondary outcomes were aneurysm/procedure related re-interventions. Results: 150 patients (92% male, mean age 73 ±8 years) were treated (within IFU 84% vs. outside IFU 16%) with the TREO device for abdominal aortic aneurysms (n=127 intact, n=17 symptomatic and n=6 ruptured; p=0.30). Technical success was achieved in 147/150 (within IFU 99% vs. outside IFU 92%, p=0.08). 30-day mortality was 2%, one year and overall mortality was 3% and 5%. During a mean follow-up of 28.4 months (range: 1–67.4 months), 35 (25%; within IFU 23% vs. outside IFU 35%, p=0.23) patients suffered from endoleaks. The majority were endoleaks type II (n=33), the remaining type Ia (n=5) and type Ib (n=3). No endoleaks type III-V, migrations or aneurysm ruptures occurred. Overall, 19 patients (13%; within IFU 13% vs. 15% outside IFU, p=0.70) received a secondary intervention: nine endoleak related endovascular procedures, three open conversions, two endograft limb related interventions, four surgical revisions of the femoral access sites and two bowl ischemia related procedures, respectively. Conclusions: This non industry-sponsored, multicenter trial indicates that using the TREO device in a real-world setting (both within and outside IFU) seems feasible in the treatment of patients suffering from AAA. While the rate of complications and secondary interventions is in line with previously published data, the findings highlight the fact that standard EVAR is associated with serious adverse events.

The aim was to analyze small abdominal aortic aneurysm (AAA) morphology during surveillance with regard to standard endovascular aortic repair (EVAR) suitability. This retrospective single-center study included all patients (n = 52, 48 male, 70 ± 8 years) with asymptomatic AAA ≤ 5.4 cm undergoing ≥2 computed tomography angiography(CTA)/magnetic resonance imaging (MRI) studies (interval: ≥6 months) between 2010 and 2018. Aneurysm diameter, neck quality (shape, length, angulation, thrombus/calcification), aneurysm thrombus, and distal landing zone diameters were compared between first and last CTA/MRI. Resulting treatment plan changes were determined. Neck shortening occurred in 25 AAA (mean rate: 2.0 ± 4.2 mm/year). Neck thrombus, present in 31 patients initially, increased in 16. Average AAA diameters were 47.7 ± 9.3 mm and 56.3 ± 11.6 mm on first and last CTA/MRI, mean aneurysm growth rate was 4.2 mm/year. Aneurysm thrombus was present in 46 patients primarily, increasing in 32. Neck thrombus growth and neck length change, aneurysm thrombus amount and aneurysm growth and aneurysm growth and neck angulation were significantly correlated. A total of 46 (88%) patients underwent open (12/46) or endovascular (34/46) surgery. The planned procedure changed from EVAR to fenestrated EVAR in two patients and from double to triple fenestrated EVAR in one. Thus, standard EVAR suitability was predominantly maintained as the threshold diameter for surgery was reached despite morphological changes. Consecutively, a possibly different pathogenesis of infra- versus suprarenal AAA merits further investigation.

Summary: Background: Ruptured juxtarenal aortic aneurysms (RJAAA) represent a special challenge in clinical practice, but the evidence to guide therapeutic decision-making is scarce. The aim of this study was to present two different approaches, open surgical (OAR) and chimney endovascular repair (CHEVAR), for treating patients with RJAAA. Patients and methods: This retrospective two-center study included all patients per center undergoing OAR or CHEVAR for RJAAA between February 2008 and January 2020. Juxtarenal aortic aneurysms were defined as having an infrarenal neck of 2–5 mm, measured after three-dimensional reconstruction of the computed tomography angiography scan. Results: 12 OAR patients (10 male, median age 73 years [58–90 years]) and 6 CHEVAR patients (all male, median age 74 years [59–83 years]) were included. In the OAR group, the proximal aortic clamping was suprarenal in 7 and interrenal in 5 patients. Cold renal perfusion was used in 4 patients, in 2 with suprarenal aortic clamping and in 2 with interrenal aortic clamping. 3 CHEVAR patients received a single renal chimney, the other 3 received double renal chimneys. Technical success was 12/12 in the OAR group 5/6 in the CHEVAR group. In-hospital mortality and 30-day mortality were 3/12 after OAR and 0/6 after CHEVAR. 2 OAR patients required transient dialysis. Median in-hospital stay was 14 (10–63) and 8 (6–21) days and median follow-up (FU) was 20 (3–37) and 30 (7–101) months, respectively. No further deaths occurred during FU. One OAR patient and 4 CHEVAR patients required aortic reinterventions. Conclusions: RJAAAs are rare. Both OAR and CHEVAR can represent adequate treatments for RJAAAs. OAR is the traditional approach, but CHEVAR has - in a high-volume center - promising early results with nonetheless a need for continuous FU to prevent reinterventions. Defining the studied aortic pathology precisely is essential for future research in order to draw valid conclusions.

Purpose: The aim of this study was to present the covered endovascular reconstruction of the iliac artery bifurcation (CERIB) technique as a revascularization option for aorto-iliac occlusive disease (AIOD) involving the iliac artery bifurcation. Methods: This was a retrospective single-center study including all patients undergoing a CERIB procedure from January 2021 until December 2022. Covered endovascular reconstruction of the iliac artery bifurcation procedures were performed percutaneously with bilateral femoral access, excepting cases where simultaneous open femoral artery reconstruction was required due to the extension of peripheral arterial occlusive disease. Standard patient, procedural, and follow-up (FU) data including survival and arterial reinterventions were gathered and analyzed. Results: A total of 13 patients were included (11/13 male, median age=70 [60-76] years). Additional open and/or endovascular procedures included endarterectomy of the femoral bifurcation (n=6), rotational atherectomy (n=2), and 1 axillary artery cutdown for upper limb access (n=1). Median operating time was 2.9 hours (1.5-4.9 hours); median radiation duration and dose were 28.4 (14.3-63.3 minutes) and 4090.6 (384.4-9430.1 cGray/cm ² ), respectively. The stent grafts used for CERIB were BeGraft peripheral n=31, BeGraft Aortic n=4 and BeGraft peripheral plus n=1 (Bentley InnoMed GmbH, Hechingen, Germany). In 2 patients with prior stenting of the common iliac artery (CIA), only the internal and external iliac arteries (IIA and EIA) were treated in this study, and in 2 cases, additional uncovered stents were required for relining. Technical success was 100%. During a midterm FU (median 18 [4-31] months), 2 patients died from cardiovascular reasons and 1 patient with prior iliac stenting required reinterventions for recurring occlusion. Conclusion: Covered endovascular reconstruction of the iliac artery bifurcation is a straightforward option for treating AIOD involving the iliac artery bifurcation that allows preservation of internal iliac artery perfusion and shows good early and midterm results. Prior iliac artery stenting may be a risk factor for early occlusion after CERIB. Clinical impact: Aorto-iliac occlusive disease with involvement of the internal iliac artery is encountered regularly in vascular surgical practice, but the internal iliac artery is often not included in the revascularization strategy. The present article will increase the awareness for the relevance of including the internal iliac artery in revascularization strategies and presents CERIB as another method to be added to the armamentarium of (endo-)vascular surgeons and interventionalists.

The aim of this study was to evaluate our first experience with the use of the artificial intelligence-based Endoleak Risk Index (ERI) in the planning of infrarenal endovascular aortic repair with special regard on its impact on clinical decision-making. This single-center study evaluated two patient groups treated with Endurant endovascular aortic repair (EVAR). Group 1 comprised a retrospective cohort with at least 3 years of follow-up. The ERI was calculated for this group from preoperative computed tomography angiography scans and compared with the actual outcome. The prospective group 2 included patients scheduled for elective EVAR from March 2024 to March 2025, with preoperative AI-based simulations for endograft sizing including ERI calculation for type 1a endoleak (EL1a) risk prediction. The influence of ERI on clinical decision-making was assessed. Patients with noncontrast computed tomography scans or scans with slice thickness greater than 3 mm were excluded. Twenty patients were included, with 10 in each group and a median age of 70 years (range, 59-81 years) in group 1 and 72 years (range, 60-84 years) in group 2. In group 1, the ERI was elevated in six of 10 cases, with four patients experiencing perioperative or late EL1as during follow-up. Notably, two patients with elevated ERI did not develop EL1a over follow-up periods of 93 and 44 months, whereas all patients with low ERI remained free of endoleaks. Two patients in group 2 had low ERI and no EL1a, whereas two had elevated ERI for at least one simulated endograft size, leading to a change in treatment (larger endograft) for one patient. The remaining six patients had elevated ERI for all simulated sizes, with one case being unsuitable for infrarenal EVAR. Despite elevated ERI, the initial treatment plan remained unchanged for four patients, one of whom died due to cardiac reasons before implantation. Overall, no patients in group 2 developed EL1a during a median follow-up of 3 months (range, 1-12 months). This pilot study suggests that ERI calculation can be valuable even in straightforward cases, emphasizing the importance of education in the EVAR planning process. With further validation from larger datasets and advancements in technology, artificial intelligence-based EL1a risk prediction has the potential to significantly enhance EVAR planning in the future, promoting patient safety by providing tailored treatment strategies and supporting the surgeon in his decision-making.