Radiation Exposure and Contrast Agent Use during Endovascular Aortic Repair Using Mobile Versus Fixed Angiography Systems.

BACKGROUND: For (thoracic) endovascular aortic repair ((T)EVAR) procedures, both mobile (standard operating room (SOR)) and fixed C-arm (hybrid operating room (HOR)) systems are available. This study evaluated differences in key procedural parameters, and procedural success for (T)EVAR in the SOR versus the HOR. METHODS: All patients who underwent standard elective (T)EVAR at the Clinic for Vascular and Endovascular Surgery at the University Hospital Duesseldorf, Germany, between 1 January 2012 and 1 January 2019 were included. Data were retrieved from archived medical records. Endpoints were analyzed for SOR versus HOR during (T)EVAR. RESULTS: A total of 93 patients, including 50 EVAR (SOR (n = 20); HOR (n = 30)) and 43 TEVAR (SOR (n = 22); HOR (n= 21)) were included. The dose area product (DAP) for EVAR and TEVAR was lower in the SOR than in the HOR (EVAR, SOR: 1635 ± 1088 cGy·cm2; EVAR, HOR: 7819 ± 8928 cGy·cm2; TEVAR, SOR: 8963 ± 34,458 cGy·cm2; TEVAR, HOR: 14,591 ± 11,584 cGy·cm2 (p < 0.05)). Procedural fluoroscopy time was shorter in the SOR than in the HOR for EVAR and TEVAR (EVAR, SOR: 7 ± 4 min; EVAR, HOR: 18.8 ± 11.3 min; TEVAR, SOR: 6.6 ± 9.6 min; TEVAR, HOR: 13.9 ± 11.8 min (p < 0.05)). Higher volumes of contrast agent were applied during EVAR and TEVAR in the SOR than in the HOR (EVAR, SOR: 57.5 ± 20 mL; EVAR: HOR: 33.3 ± 5 mL (p < 0.05); TEVAR; SOR: 71.5 ± 53.4 mL, TEVAR, HOR: 48.2 ± 27.5 mL (p ≥ 0.05). CONCLUSION: The use of a fixed C-arm angiography system in the HOR results in higher radiation exposure and longer fluoroscopy times but lower contrast agent volumes when compared with mobile C-arm systems in the SOR. Because stochastic radiation sequelae are more likely to be tolerated in an older patient population and, in addition, there is a higher incidence of CKD in this patient population, allocation of patients to the HOR for standard (T)EVAR seems particularly advisable based on our results.

Relative Thrombus Burden Ratio Reveals Overproportioned Intraluminal Thrombus Growth-Potential Implications for Abdominal Aortic Aneurysm.

Background: An intraluminal, non-occlusive thrombus (ILT) is a common feature in an abdominal aortic aneurysm (AAA). This study investigated the relative progression of ILT vs. AAA volume using a novel parameter, the so-called thrombus burden ratio (TBR), in non-treated AAAs. Parameters potentially associated with TBR progression were analyzed and TBR progression in large vs. small and fast- vs. slow-growing AAAs was assessed. Methods: This retrospective, single-center study analyzed sequential contrast-enhanced computed tomography angiography (CTA) scans between 2009 and 2018 from patients with an AAA before surgical treatment. Patients' medical data and CTA scans were analyzed at two given time points. The TBR was calculated as a ratio of ILT and AAA volume, and relative TBR progression was calculated by normalization for time between sequential CTA scans. Spearman's correlation was applied to identify morphologic parameters correlating with TBR progression, and multivariate linear regression analysis was used to evaluate the association of clinical and morphological parameters with TBR progression. Results: A total of 35 patients were included. The mean time between CT scans was 16 ± 15.9 months. AAA volume progression was 12 ± 3% and ILT volume progression was 36 ± 13%, resulting in a TBR progression of 11 ± 4%, suggesting overproportioned ILT growth. TBR progression was 0.8 ± 0.8% per month. Spearman's correlation verified ILT growth as the most relevant parameter contributing to TBR progression (R = 0.51). Relative TBR progression did not differ significantly in large vs. small and fast- vs. slow-growing AAAs. In the multivariate regression analysis, none of the studied factors were associated with TBR progression. Conclusion: TBR increases during AAA development, indicating an overproportioned ILT vs. AAA volume growth. The TBR may serve as a useful parameter, as it incorporates the ILT volume growth relative to the AAA volume, therefore combining two important parameters that are usually reported separately. Yet, the clinical relevance in helping to identify potential corresponding risk factors and the evaluation of patients at risk needs to be further validated in a larger study cohort.

The Comparison of Endovascular and Open Surgical Treatment for Ruptured Abdominal Aortic Aneurysm in Terms of Safety and Efficacy on the Basis of a Single-Center 30-Year Experience.

OBJECTIVE: Ruptured abdominal aortic aneurysm (rAAA) is a critical condition with a high mortality rate. Over the years, endovascular aortic repair (EVAR) has evolved as a viable treatment option in addition to open repair (OR). The primary objective of this study was to compare the safety and efficacy of EVAR and OR for the treatment of rAAA based on a comprehensive analysis of our single-centre 30-year experience. METHODS: Patients treated for rAAA at the Department of Vascular and Endovascular Surgery, University Hospital Düsseldorf, Germany from 1 January 1993 to 31 December 2022 were included. Relevant information was retrieved from archived medical records. Patient survival and surgery-related complications were analysed. RESULTS: None of the patient-specific markers, emergency department-associated parameters, and co-morbidities were associated with patient survival. The 30-day and in-hospital mortality was higher in the OR group vs. in the EVAR group (50% vs. 8.7% and 57.1% vs. 13%, respectively). OR was associated with more frequent occurrence of more severe complications when compared to EVAR. Overall patient survival was 56 ± 5% at 12 months post-surgery (52 ± 6% for OR vs. 73 ± 11% for EVAR, respectively) (p < 0.05). Patients ≥70 years of age showed poorer survival in the OR group, with a 12-month survival of 42 ± 7% vs. 70 ± 10% for patients <70 years of age (p < 0.05). In the EVAR group, this age-related survival advantage was not found (12-month survival: ≥70 years: 67 ± 14%, <70 years: 86 ± 13%). Gender-specific survival was similar regardless of the applied method of care. CONCLUSION: OR was associated with more severe complications in our study. EVAR initially outperformed OR for rAAA regarding patient survival while re-interventions following EVAR negatively affect survival in the long-term. Elderly patients should be treated with EVAR. Gender does not seem to have a significant impact on survival.

Effect of Gelatin-Based Hemostats on Fibroblasts and Relevant Growth Factors in Wound Healing.

Gelatin-based hemostats have been used in various surgical fields and showed advantageous effects on central aspects of wound healing when compared to cellulose-based hemostats. Nevertheless, the influence of gelatin-based hemostats on wound healing has not been fully explored yet. Hemostats were applied to fibroblast cell cultures for 5, 30, 60 min, 24 h, 7 and 14 days and measurements were taken at 3, 6, 12, 24 h and 7 or 14 days, respectively. Cell proliferation was quantified after different exposure times and a contraction assay was conducted to measure the extent of the extracellular matrix over time. We further assessed quantitative levels of vascular endothelial growth factor and basic fibroblast growth factor using enzyme-linked immunosorbent assay. Fibroblast counts decreased significantly at 7 and 14 days independent of the application duration (p < 0.001 for 5 min application). The gelatin-based hemostat did not have a negative impact on cell matrix contraction. After application of gelatin-based hemostat, the basic fibroblast growth factor did not change; yet, the vascular endothelial growth factor significantly increased after a prolonged 24 h application time when compared to controls or to a 6 h exposure (p < 0.05). Gelatin-based hemostats did not impair contraction of the extracellular matrix or growth factor production (vascular endothelial growth factor and basic fibroblast growth factor), while cell proliferation diminished at late time points. In conclusion, the gelatin-based material seems to be compatible with central aspects of wound healing. For further clinical assessment, future animal and human studies are necessary.

Time-dependent effects of cellulose and gelatin-based hemostats on cellular processes of wound healing.

Introduction: Oxidized regenerated cellulose-based (ORC - TABOTAMP), oxidized non-regenerated cellulose-based (ONRC - RESORBA CELL), and gelatin-based (GELA - GELITA TUFT-IT) hemostats are commonly used in surgery. However, their impact on the wound healing process remains largely unexplored. We here assess time-dependent effects of exposure to these hemostats on fibroblast-related wound healing processes. Material and methods: Hemostats were applied to fibroblast cell cultures for 5-10 (short-), 30 and 60 min (intermediate-) and 24 h (long-term). Representative images of the hemostat degradation process were obtained, and the pH value was measured. Cell viability, apoptosis and migration were analyzed after the above exposure times at 3, 6 and 24 h follow-up. Protein levels for tumor necrosis factor α (TNF-α) and transforming-growth factor ß (TGF-ß) were assessed. Results: ORC and ONRC reduced pH values during degradation, while GELA proved to be pH-neutral. Hemostat structural integrity was prolonged for GELA (vs. ORC and ONRC). TGF-ß and TNF-α levels were reduced for ORC and ONRC (vs. GELA and control) (p < 0.05). Further, exposure of ORC and ONRC for longer than 5-10 min reduced cell viability vs. GELA and control at 3 h post-exposure (p < 0.05). Similarly, cell migration was impaired with ORC and ONRC exposure longer than 60 min at 24 h follow-up (p < 0.05). Conclusions: Short-term exposure to ORC and ONRC impairs relevant wound healing-related processes in fibroblasts, and alters protein levels of key mediating cytokines. GELA does not show similar effects. We conclude that GELA may be preferred over ORC and ONRC over short-, intermediate- and long-term exposures. Future validation of the clinical relevance is warranted.

Percutaneous fractionated radiotherapy of the groin to eliminate lymphatic fistulas after vascular surgery.

BACKGROUND: Vascular surgery of the inguinal area can be complicated by persistent lymphatic fistulas. Rapid and effective treatment is essential to prevent infection, sepsis, bleeding, and possible leg amputation. Current data on irradiation of lymphatic fistulas lack recommendation on the appropriate individual and total dose, the time of irradiation, and the target volume. Presumably, a dose of 0.3-0.5 to 1-12 Gy should be sufficient for the purpose. Currently, radiotherapy is a "can" recommendation, with a level 4 low evidence and a grade C recommendation, according to the DEGRO S2 guidelines. As part of a pilot study, we analyzed the impact and limitations of low-dose radiation therapy in the treatment of inguinal lymphatic fistulas. PATIENTS AND METHODS: As a part of an internal quality control project, patients with lymphatic fistulas irradiated in the groin area after vascular surgery for arterial occlusive disease (AOD) III-IV, repair of pseudo aneurysm or lymph node dissection due to melanoma were selected, and an exploratory analysis on retrospectively collected data performed. RESULTS: Twelve patients (10 males and 2 females) aged 62.83 ± 12.14 years underwent open vascular reconstruction for stage II (n = 2), III (n = 1), and IV (n = 7) arterial occlusive disease (AOD), lymph node dissection for melanoma (n = 1) or repair of a pseudoaneurysm (n = 1). Surgical vascular access was obtained through the groin and was associated with a persistent lymphatic fistula, secreting more than 50 ml/day. Patients were irradiated five times a week up to a maximum of 10 fractions for the duration of the radiation period. Fraction of 0.4 Gy was applied in the first 7 cases, while 5 patients were treated with a de-escalating dose of 0.3 Gy. There was a resolution of the lymphatic fistula in every patient without higher grade complications. CONCLUSION: Low-dose irradiation of the groin is a treatment option for persistent lymphatic fistula after inguinal vascular surgery.

Gene Therapy of Chronic Limb-Threatening Ischemia: Vascular Medical Perspectives.

A decade ago, gene therapy seemed to be a promising approach for the treatment of chronic limb-threatening ischemia, providing new perspectives for patients without conventional, open or endovascular therapeutic options by potentially enabling neo-angiogenesis. Yet, until now, the results have been far from a safe and routine clinical application. In general, there are two approaches for inserting exogenous genes in a host genome: transduction and transfection. In case of transduction, viral vectors are used to introduce genes into cells, and depending on the selected strain of the virus, a transient or stable duration of protein production can be achieved. In contrast, the transfection of DNA is transmitted by chemical or physical processes such as lipofection, electro- or sonoporation. Relevant risks of gene therapy may be an increasing neo-vascularization in undesired tissue. The risks of malignant transformation and inflammation are the potential drawbacks. Additionally, atherosclerotic plaques can be destabilized by the increased angiogenesis, leading to arterial thrombosis. Clinical trials from pilot studies to Phase II and III studies on angiogenic gene therapy show mainly a mixed picture of positive and negative final results; thus, the role of gene therapy in vascular occlusive disease remains unclear.

Reconstruction for Symptomatic Vertebral Artery Lesion Using Vertebral Artery to Carotid Artery Transposition: A Retrospective Study.

BACKGROUND: A posterior circulation infarction is caused by a vertebral artery (VA) lesion (stenosis or occlusion). The purpose of this study is to assess early and long-term outcomes after open surgery for a VA lesion at the origin. METHODS: In a retrospective study conducted from January 1, 2000 through March 31, 2020 in a single center, patients were treated with vertebral artery to carotid artery transposition (VCT). RESULTS: A total of 28 patients, with a mean age of 65.29 ± 9.81 years (range 45-84), were screened, including 22 patients with VA stenosis and 6 patients with VA occlusion. The complication rate was 21.4% (n = 6), including Horner syndrome (n = 2), lymphocele (n = 1), respiratory failure (n = 1), embolism of a subclavian artery stenosis (n = 1), and vocal cord paralysis (n = 1). The 30-day mortality rate was 0%. Primary patency was 100%. Overall, improvement in symptoms was 85.7% (n = 24) after surgery and 96.4% after 30 days. In the long-term results, primary patency was 100%, and the cumulative patency rate after 60 months was 85.7%, with 1 occlusion of the VA. Cumulative survival rates were 94%, 87%, 69%, and 59% after 12, 24, 60, and 72 months (n = 5). One of the 3 patients died after 60 months because of VA occlusion and posterior circulation infarction. CONCLUSIONS: VCT is a safe, effective, and durable procedure. It provides good stroke protection, symptomatic relief, and perioperative risk at acceptable levels, in experienced hands.