Acute abdominal aortic occlusion: A 16-year single-center experience.

BACKGROUND: Acute abdominal aortic occlusion (AAO) is a rare vascular emergency associated with high morbidity and mortality. In the present study, we analyzed the clinical management and outcomes for a consecutive patient series during a 16-year period. METHODS: We included all patients with an acute AAO and bilateral acute limb ischemia who had been treated between 2004 and 2019. Patients with dissection, aneurysm rupture, or chronic occlusive disease were excluded. The patient characteristics, surgical procedures, and outcomes were extracted retrospectively from a prospective aortic database, electronic patient files, and outpatient examination records. The extent of ischemia was classified according to the TASC II (Inter-Society Consensus for the Management of Peripheral Arterial Disease) section on acute limb ischemia. The primary endpoints were 30-day mortality (safety endpoint) and the combined 6-month amputation and/or death rate (efficacy endpoint). The follow-up outcomes, amputation rates, and 30-day complications were evaluated as secondary endpoints. The patient cohort was divided into four 4-year groups (2004-2007, 2008-2011, 2012-2015, 2016-2019) to assess the outcome changes over time. Statistical analysis included χ2 tests and univariate and linear regression analyses. RESULTS: A total of 74 patients (57% male; median age, 64.5 years) with an acute AAO were identified. Arterial thrombosis was the most common etiology (66%). The extent of ischemia was TASC I, IIa, IIb, and III in 7%, 39%, 40%, and 14%, respectively. The patient numbers had increased significantly over time (P = .016). Of the patients, 42% had undergone open transfemoral recanalization (including hybrid procedures), 35% open aortic surgery, 15% extra-anatomic bypass surgery, and 5% (four patients) endovascular therapy alone. The overall 30-day mortality rate was 23%, and the 6-month amputation and/or death rate was 43%. The 30-day mortality rate had declined significantly from 54% for 2004 to 2007 to 10% for 2011 to 2015 (odds ratio [OR], 0.10; 95% confidence interval [CI], 0.001-0.52) and 20% for 2016 to 2019 (OR, 0.21; 95% CI, 0.05-0.90), a statistically nonsignificant trend showing that the relative decline in the use of open aortic procedures was associated with decreased 30-day mortality (P = .06). Univariate analysis indicated that elevated serum lactate on admission (OR, 3.33; 95% CI, 1.06-10.48) and an advanced stage of limb ischemia (OR, 4.33), were strongly associated with an increased 30-day mortality rate. The incidence of severe postoperative systemic complications also indicated a greater incidence of both primary endpoints. The 6-month amputation and/or mortality rates were also affected by the presence of atrial fibrillation (OR, 3.63; 95% CI, 1.34-9.79) and increased patient age (OR, 3.96; 95% CI, 1.49-10.53). CONCLUSIONS: Acute AAO remains a life-threatening emergency. Immediate transfemoral open or endovascular techniques should be preferred, if technically possible and proper intraoperative imaging is available.

A Modern Series of Secondary Aortoenteric Fistula - A 19-Year Experience.

OBJECTIVES: Secondary aortoenteric fistula is a rare and life-threatening condition. Clear evidence on the ideal therapeutic approach is largely missing. This study aims to analyze symptoms, etiology, risk factors, and outcomes based on procedural details. PATIENTS AND METHODS: All patients with secondary aortoenteric fistula admitted between 2003 and 2021 were included. Patient characteristics, surgical procedure details, and postoperative outcomes were analyzed. Outcomes were stratified and compared according to the urgency of operation and the procedure performed. Descriptive statistics were used. The primary endpoint was in-hospital mortality. RESULTS: A total of twentytwo patients (68% male, median age 70 years) were identified. Main symptoms were gastrointestinal bleeding, pain, and fever. From the twentytwo patients ten patients required emergency surgery and ten urgent surgery. Emergency patients were older on average (74 vs 63 years, P = .015) and had a higher risk of postoperative respiratory complications (80% vs 10%, P = .005). Primary open surgery with direct replacement of the aorta or an extra-anatomic bypass with an additional direct suture or resection of the involved bowel was performed in sixteen patients. In four patients underwent endovascular bridging treatment with the definitive approach as a second step. Other two patients died without operation (1x refusal; 1x palliative cancer history). In-hospital mortality was 27%, respectively. Compared to patients undergoing urgent surgery, those treated emergently showed significantly higher in-hospital (50% vs 0%, P = .0033) mortalities. CONCLUSION: Despite rapid diagnosis and treatment, secondary aortoenteric fistula remains a life-threatening condition with 27% in-hospital mortality, significantly increased upon emergency presentation.

Skeletal muscle optoacoustics reveals patterns of circulatory function and oxygen metabolism during exercise.

Imaging skeletal muscle function and metabolism, as reported by local hemodynamics and oxygen kinetics, can elucidate muscle performance, severity of an underlying disease or outcome of a treatment. Herein, we used multispectral optoacoustic tomography (MSOT) to image hemodynamics and oxygen kinetics within muscle during exercise. Four healthy volunteers underwent three different hand-grip exercise challenges (60s isometric, 120s intermittent isometric and 60s isotonic). During isometric contraction, MSOT showed a decrease of HbO2, Hb and total blood volume (TBV), followed by a prominent increase after the end of contraction. Corresponding hemodynamic behaviors were recorded during the intermittent isometric and isotonic exercises. A more detailed analysis of MSOT readouts revealed insights into arteriovenous oxygen differences and muscle oxygen consumption during all exercise schemes. These results demonstrate an excellent capability of visualizing both circulatory function and oxygen metabolism within skeletal muscle under exercise, with great potential implications for muscle research, including relevant disease diagnostics.

The Incidence of IgG4-Related and Inflammatory Abdominal Aortic Aneurysm Is Rare in a 101 Patient Cohort.

Abdominal aortic aneurysms (AAA) are the most frequent aortic dilation, with considerable morbidity and mortality. Inflammatory (infl) and IgG4-positive AAAs represent specific subtypes of unclear incidence and clinical significance. Here, histologic and serologic analyses with retrospective clinical data acquisition are investigated via detailed histology, including morphologic (HE, EvG: inflammatory subtype, angiogenesis, and fibrosis) and immunhistochemic analyses (IgG and IgG4). In addition, complement factors C3/C4 and immunoglobulins IgG, IgG2, IgG4 and IgE were measured in serum samples and clinical data uses patients' metrics, as well as through semi-automated morphometric analysis (diameter, volume, angulation and vessel tortuosity). A total of 101 eligible patients showed five (5%) IgG4 positive (all scored 1) and seven (7%) inflammatory AAAs. An increased degree of inflammation was seen in IgG4 positive and inflAAA, respectively. However, serologic analysis revealed no increased levels of IgG or IgG4. The operative procedure time was not different for those cases and the short-term clinical outcomes were equal for the entire AAA cohort. Overall, the incidence of inflammatory and IgG4-positive AAA samples seems very low based on histologic and serum analyses. Both entities must be considered distinct disease phenotypes. Short-term operative outcomes were not different for both sub-cohorts.

Patients with Acute Limb Ischemia Might Benefit from Endovascular Therapy-A 17-Year Retrospective Single-Center Series of 985 Patients.

Acute lower limb ischemia (ALI) is a common vascular emergency, requiring urgent revascularization by open or endovascular means. The aim of this retrospective study was to evaluate patient demographics, treatment and periprocedural variables affecting the outcome in ALI patients in a consecutive cohort in a tertiary referral center. Primary outcome events (POE) were 30-day (safety) and 180-day (efficacy) combined mortality and major amputation rates, respectively. Secondary outcomes were perioperative medical and surgical leg-related complications and the 5-year combined mortality and major amputation rate. Statistical analysis used descriptive and uni- and multivariable Cox regression analysis. In 985 patients (71 ± 9 years, 56% men) from 2004 to 2020, the 30-day and 180-day combined mortality and major amputation rates were 15% and 27%. Upon multivariable analysis, older age (30 d: aHR 1.17; 180 d: 1.27) and advanced Rutherford ischemia stage significantly worsened the safety and efficacy POE (30 d: TASC IIa aHR 3.29, TASC IIb aHR 3.93, TASC III aHR 7.79; 180 d: TASC IIa aHR 1.97, TASC IIb aHR 2.43, TASC III aHR 4.2), while endovascular treatment was associated with significant improved POE after 30 days (aHR 0.35) and 180 days (aHR 0.39), respectively. Looking at five consecutive patient quintiles, a significant increase in endovascular procedures especially in the last quintile could be observed (17.5% to 39.5%, p < 0.001). Simultaneously, the re-occlusion rate as well as the number of patients with any previous revascularization increased. In conclusion, despite a slightly increasing early re-occlusion rate, endovascular treatment might, if possible, be favorable in ALI treatment.

Biobanking: Objectives, Requirements, and Future Challenges-Experiences from the Munich Vascular Biobank.

Collecting biological tissue samples in a biobank grants a unique opportunity to validate diagnostic and therapeutic strategies for translational and clinical research. In the present work, we provide our long-standing experience in establishing and maintaining a biobank of vascular tissue samples, including the evaluation of tissue quality, especially in formalin-fixed paraffin-embedded specimens (FFPE). Our Munich Vascular Biobank includes, thus far, vascular biomaterial from patients with high-grade carotid artery stenosis (n = 1567), peripheral arterial disease (n = 703), and abdominal aortic aneurysm (n = 481) from our Department of Vascular and Endovascular Surgery (January 2004⁻December 2018). Vascular tissue samples are continuously processed and characterized to assess tissue morphology, histological quality, cellular composition, inflammation, calcification, neovascularization, and the content of elastin and collagen fibers. Atherosclerotic plaques are further classified in accordance with the American Heart Association (AHA), and plaque stability is determined. In order to assess the quality of RNA from FFPE tissue samples over time (2009⁻2018), RNA integrity number (RIN) and the extent of RNA fragmentation were evaluated. Expression analysis was performed with two housekeeping genes-glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and beta-actin (ACTB)-using TaqMan-based quantitative reverse-transcription polymerase chain reaction (qRT)-PCR. FFPE biospecimens demonstrated unaltered RNA stability over time for up to 10 years. Furthermore, we provide a protocol for processing tissue samples in our Munich Vascular Biobank. In this work, we demonstrate that biobanking is an important tool not only for scientific research but also for clinical usage and personalized medicine.