Risk Factors for Mortality and Promoting Factors for Ambulation After Major Lower Limb Amputation for End-Stage Arterial Disease: A Multicenter Study.

BACKGROUND: Around 1%-2% of patients with peripheral arterial disease will require a lower limb amputation at some point. Despite advancements in prevention and treatment, mortality after major amputation remains high. The aim of this study was to investigate the risk factors related to mortality and promoting factors for ambulation postamputation. METHODS: A multicenter retrospective study of consecutive major lower limb amputation patients performed at the department of thoracic and vascular surgery of the University Hospitals Ghent and Leuven between January 2008 and December 2017. RESULTS: Three hundred and thirteen patients met the inclusion criteria. Overall, 1-year mortality rate was 29.7% with age being the most important risk factor. Above-knee amputations had significantly higher mortality (37%) than below-knee amputations (22%) at 1 year. Diabetes and number of vascular interventions were not linked to higher mortality. Age, amputation level, and presence of hypertension were the most important determining factors for successful ambulation. CONCLUSIONS: Maintaining the independency of patients, whether this is obtained by maximizing limb salvage or primary amputation, is critical. Knowledge about the factors that play a role in the risk of death and the chance of regaining ambulation is important to include in the decision-making conversation with the patient.

Potential therapeutic effect of a ketogenic diet for the treatment of lymphoedema: Results of an exploratory study.

BACKGROUND: Lymphoedema is a chronic and progressive disease characterised by excessive accumulation of lymph in the interstitial compartment, leading to tissue swelling and fibroadipose deposition. Lymphangiogenesis is partly regulated by ketone body oxidation, and a ketogenic diet (KD) has shown therapeutic efficacy in a preclinical mouse tail lymphoedema model. Therefore, we aimed to investigate the potential therapeutic effect of a KD in patients with secondary lymphoedema. METHODS: Nine patients with unilateral stage 2 lymphoedema secondary to lymphadenectomy were included in this quasi-experimental exploratory study consisting of a short run-in phase to gradually induce ketosis, followed by a classic KD (CKD) and modified Atkins diet (MAD) phase during which patients consumed a CKD and MAD, respectively. Lymphatic function and oedema volume, the primary outcomes, were assessed at baseline and at the end of both the CKD and MAD phase. Secondary outcomes included health-related and lymphedema-specific quality of life (QoL). RESULTS: Seven out of nine patients completed the study protocol. Lymphatic function was improved upon consumption of both a CKD (dermal backflow score [mean ± SD]: 7.29 ± 2.98 vs. 10.86 ± 2.19 at baseline; p = 0.03) and MAD (6.71 ± 2.06; p = 0.02), whereas oedema volume did not decrease during the course of the study (excess limb volume [mean ± SD]: 20.13 ± 10.25% at end of CKD and 24.07 ± 17.77% at end of MAD vs. 20.79 ± 12.96% at baseline; p > 0.99 and p > 0.30, respectively). No changes were observed in health-related, nor lymphoedema-specific QoL at the end of CKD and MAD. CONCLUSIONS: The consumption of a KD improved lymphatic function and was associated with a clinically meaningful reduction in oedema volume in some patients (3/7 at end of CKD, 2/7 at end of MAD) with unilateral stage 2 secondary lymphoedema. These results highlight the potential of a KD to improve lymphatic function in patients with lymphoedema. However, further studies are required to substantiate our findings.

Massed Training is Logistically Superior to Distributed Training in Acquiring Basic Endovascular Skills.

OBJECTIVE: A "PROficiency based StePwise Endovascular Curricular Training" (PROSPECT) has proven its superiority over traditional training in a randomised controlled trial to acquire basic endovascular skills outside theatre, but real life adherence is low. This study aimed to compare the original distributed training format, where trainees learn at their own pace, with a massed training format offering the same content within a limited time span while exempt from clinical duties. Secondly, long term skills retention was evaluated. METHODS: A multicentre, prospective study allocated participants to the distributed D-PROSPECT or to a massed, compact version (C-PROSPECT) based on logistics such as travel time, participant and instructor availability. A multiple choice question (MCQ) test (max. score 20) tested cognitive skills. Technical skills were assessed using a global rating scale (GRS) (max. score 55), examiner's checklist (max. score 85), and validated simulator metrics. Data were collected pre- and post-programme and at three, six, and 12 months after programme completion. RESULTS: Over four years and in two countries, D-PROSPECT was implemented in two centres and C-PROSPECT in three. A total of 22 participants completed D-PROSPECT with a 41% dropout rate, and 21 completed C-PROSPECT with 0% dropout rate. All participants showed significant improvement for all performance parameters after programme completion: MCQ test (median 14.5 vs. 18; p < .001), GRS (median 20 vs. 41; p < .001), examiner's checklist (median 49 vs. 78.5; p < .001), and simulation metrics (p < .001). Scores of C- or D-PROSPECT participants were not significantly different. No significant differences were seen between groups during the retention period. CONCLUSION: PROSPECT significantly improves the quality of simulated endovascular performances using a massed or distributed training format. A massed training format of PROSPECT may be preferred to decrease dropout during standardised training to obtain basic endovascular skills in existing surgical curricula.

Editor's Choice - Infective Native Aortic Aneurysms: A Delphi Consensus Document on Terminology, Definition, Classification, Diagnosis, and Reporting Standards.

OBJECTIVE: There is no consensus regarding the terminology, definition, classification, diagnostic criteria, and algorithm, or reporting standards for the disease of infective native aortic aneurysm (INAA), previously known as mycotic aneurysm. The aim of this study was to establish this by performing a consensus study. METHODS: The Delphi methodology was used. Thirty-seven international experts were invited via mail to participate. Four two week Delphi rounds were performed, using an online questionnaire, initially with 22 statements and nine reporting items. The panellists rated the statements on a five point Likert scale. Comments on statements were analysed, statements revised, and results presented in iterative rounds. Consensus was defined as ≥ 75% of the panel selecting "strongly agree" or "agree" on the Likert scale, and consensus on the final assessment was defined as Cronbach's alpha coefficient > .80. RESULTS: All 38 panellists completed all four rounds, resulting in 100% participation and agreement that this study was necessary, and the term INAA was agreed to be optimal. Three more statements were added based on the results and comments of the panel, resulting in a final 25 statements and nine reporting items. All 25 statements reached an agreement of ≥ 87%, and all nine reporting items reached an agreement of 100%. The Cronbach's alpha increased for each consecutive round (round 1 = .84, round 2 = .87, round 3 = .90, and round 4 = .92). Thus, consensus was reached for all statements and reporting items. CONCLUSION: This Delphi study established the first consensus document on INAA regarding terminology, definition, classification, diagnostic criteria, and algorithm, as well as reporting standards. The results of this study create essential conditions for scientific research on this disease. The presented consensus will need future amendments in accordance with newly acquired knowledge.

Long-term outcome results after endovascular aortoiliac aneurysm repair with the bifurcated EXCLUDER Endoprosthesis.

OBJECTIVE: To report the long-term outcome of patients presenting with an aortic, aortoiliac, or isolated common iliac aneurysm treated with the bifurcated EXCLUDER Endoprosthesis. Furthermore, potential differences in late outcome results between the original- and low-permeability endoprosthesis were analyzed. METHODS: A retrospective analysis of prospectively collected data of 182 patients who underwent endovascular aneurysm repair with the EXCLUDER Endoprosthesis between June 1998 and October 2015 in an academic, tertiary care center for aortic disease was performed. Patient follow-up was from 3 to 20 years (mean follow-up of 6.9 years). Primary end points were overall survival and reintervention-free survival. Secondary end points were device-related complications, endoleaks, and reinterventions. RESULTS: Overall survival at 5, 10, and 15 years was 72.8%, 42.1%, and 12.2%, respectively, with no aneurysm-related mortality and no difference in overall survival between the original- vs low-permeability endoprosthesis group (P = .617). Freedom from type I endoleak at 5 years was 94.8%. No new type I endoleak was detected beyond the 5-year follow-up mark. No type III endoleak was identified. Reintervention-free survival was 83.6%, 66.7%, and 66.7% at 5-, 10-, and 15-year follow-up, respectively. There was a significant difference in intervention-free survival between the original- vs low-permeability endoprosthesis group (P = .029) and after the 5-year follow-up mark. In addition, patients with the low-permeability endoprosthesis showed significantly fewer device-related complications (P = .002) and endoleaks (P = .005). CONCLUSIONS: Endovascular aneurysm repair using the EXCLUDER Endoprosthesis is effective and durable on long-term follow-up, with acceptably low device-related complications and reinterventions. The low-permeability endoprosthesis was associated with significantly fewer new device-related complications and endoleaks after 5 years of follow-up.

Clinical Studies Reporting on Vascular Graft Coatings for the Prevention of Aortic Graft Infection: A Systematic Review and Meta-Analysis.

OBJECTIVE: The aim of this study was to investigate the efficacy of vascular graft coatings used in the aortic position to prevent vascular graft infection (VGI). METHODS: A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines using a pre-registered protocol (CRD42020206436). Eligible studies used a vascular graft coating in the aortic position and reported on VGI. A search was performed in MEDLINE (PubMed), Embase, Web of Science, and the Cochrane Library. Primary outcome parameters were VGI, patency, and mortality. Pooled estimates of VGI were calculated using odds ratio (OR) and 95% confidence intervals (CIs) wherever possible. Quality assessment was performed with the Newcastle-Ottawa Assessment Scale and the Revised Cochrane risk of bias tool for randomised trials. RESULTS: In total, 6 873 papers were identified. Only eight studies were included. Six of eight studies (75%) reported on known antimicrobial coating strategies such as antibiotics (n = 3) and silver (n = 3). In the other two studies, polymer coated grafts were used. Only three of eight studies compared coated with uncoated grafts (two antibiotic and one silver). Two randomised controlled trials reported on the effect of rifampicin soaked (1 mg/mL) grafts and showed no significant effect in the early (2 months; OR 0.69, 95% CI 0.29 - 1.62) or late (2 years; OR 0.73, 95% CI 0.23 - 2.32) post-operative periods. A retrospective cohort study focusing on the effect of silver coated grafts did not reveal any advantage (OR 0.19, 95% CI 0.02 - 1.64). Two polymer coated grafts were not considered to have a potential benefit in the prevention of VGIs. CONCLUSION: Clinical studies reporting on the antibacterial effect of vascular graft coatings in the aortic position to prevent VGI are scarce. For silver and antibiotic coatings, no significant protection for VGI was observed. New types of grafts or long acting coating strategies are mandatory to prevent this complication in the future.

Pre-clinical In Vitro Models of Vascular Graft Coating in the Prevention of Vascular Graft Infection: A Systematic Review.

OBJECTIVE: Vascular graft infection (VGI) is a feared complication. Prevention is of the utmost importance and vascular graft coatings (VGCs) could offer a potential to do this, with in vitro research a first crucial step. The aim of this study was to summarise key features of in vitro models investigating coating strategies to prevent VGI in order to provide guidance for the setup of future translational research. DATA SOURCES: A comprehensive search was performed in MEDLINE, Embase, and Web of Science. METHODS: A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. For each database, a specific search strategy was developed. Quality was assessed with the Toxicological data Reliability Assessment Tool (ToxRTool). In vitro models using a VGC and inoculation of the graft with a pathogen were included. The type of graft, coating, and pathogen were summarised. The outcome assessment in each study was evaluated. RESULTS: In total, 4 667 studies were identified, of which 45 papers met the inclusion criteria. The majority used polyester grafts (68.2%). Thirty-one studies (68.9%) included antibiotics, and nine studies (20%) used a commercial silver graft in their protocol. New antibacterial strategies (e.g., proteolytic enzymes) were investigated. A variety of testing methods was found and focused mainly on bacterial adherence, coating adherence and dilution, biofilm formation, and cytotoxicity. Ninety-three per cent of the studies (n = 41) were considered unreliable. CONCLUSION: Polyester is the preferred type of graft to coat on. The majority of coating studies are based on antibiotics; however, new coating strategies (e.g., antibiofilm coating) are coming. Many in vitro setups are available. In vitro studies have great potential, they can limit the use, but cannot replace in vivo studies completely. This paper can be used as a guidance document for future in vitro research.

Vascular Graft Infections With Candida: A Factor for Increased Mortality in in-situ Reconstructions.

BACKGROUND: The empiric antibiotic regimen started after deep cultures and explantation of the graft mostly do not cover antifungals. We retrospectively studied the outcome of candida compared to non-candida VGI and assessed whether these results could justify the addition of antifungals to the empiric antibiotics in the early postoperative period. METHODS: All patients treated for infected aorto(ilio)femoral graft with excision and reconstruction at the vascular department of University Hospitals Leuven between January 2010 and 2017 (n = 56) were studied retrospectively. Patients were allocated to the candida group (n = 10) or non-candida group (n = 46) according to the presence of Candida in deep culture isolates. RESULTS: All-cause mortality was significantly higher in the candida group compared to the non-candida group. All-cause 30-day mortality was 40% and 13% for both groups respectively (P = 0.066). At 5 years this was 90% and 46% respectively (P = 0.014). In the candida group 6 patients (60%) had to be revised in the operating room due to bleeding, compared to 5 patients (11%) in the non-candida group (P = 0.002).  Two patients (20%) and 5 patients (11%) had to be readmitted to the ICU, respectively. CONCLUSION: Survival of candida related VGI is significantly worse, especially in the first 5 postoperative months. This could justify the addition of an antifungal to the early empiric postoperative antibiotic cocktail, especially in patients with an aorto-enteric fistula. A cost-benefit analysis could be useful to evaluate the yield.

A Systematic Review of Strategies for Preventing Delirium in Patients Undergoing Vascular Surgery.

BACKGROUND: Elderly patients undergoing vascular surgery are at a risk of developing postoperative delirium, which is associated with high mortality. Delirium prevention is difficult and is investigated in surgical patients from various specialisms, but little is known about delirium prevention in vascular surgery. For this reason we performed a systematic review on strategies for delirium prevention in patients undergoing elective surgery for peripheral arterial disease or for an aneurysm of the abdominal aorta. METHODS: This systematic review included studies describing strategies for preventing delirium in patients undergoing elective surgery for peripheral arterial disease or for an aneurysm of the abdominal aorta. The search was conducted using the keywords 'vascular surgery,' 'prevention,' and 'delirium' and was last run on October 21, 2021 in the electronic databases PubMed, MEDLINE, Embase, Web of Science, the Cochrane library, and Emcare. Risk of bias was assessed using the Cochrane risk of bias tool for randomized controlled trials and the ROBINS-1 tool for observational studies. RESULTS: Four studies including 565 patients were included in the systematic review. A significant decrease in the incidence of delirium was reported by a study investigating the effect of comprehensive geriatric assessments within patients undergoing surgery for an aneurysm of the abdominal aorta or lower limb bypass surgery (24% in the control group vs. 11% in the intervention group, P = 0.018) and in the total group of a study evaluating the effect of outpatient clinic multimodal prehabilitation for patients with an aneurysm of the abdominal aorta (11.7% in the control group vs. 8.2% in the intervention group, P = 0.043, Odds Ratio = 0.56). A nonsignificant decrease in delirium incidence was described for patients receiving a multidisciplinary quality improvement at the vascular surgical ward (21.4% in the control group vs. 14.6% in the intervention group, P = 0.17). The study concerning the impact of the type of anesthesia on delirium in 11 older vascular surgical patients, of which 3 developed delirium, did not differentiate between the different types of anesthesia the patients received. CONCLUSIONS: Despite the high and continuous increasing incidence of delirium in the growing elderly vascular population, little is known about effective preventive strategies. An approach to address multiple risk factors simultaneously seems to be promising in delirium prevention, whether through multimodal prehabilitation or comprehensive geriatric assessments. Several strategies including prehabilitation programs have been proven to be successful in other types of surgery and more research is required to evaluate effective preventive strategies and prehabilitation programs in vascular surgical patients.

Age-Dependent Outcome of First-Line Endovascular and Surgical Revascularization Strategies in Chronic Limb-Threatening Ischemia.

BACKGROUND: Chronic limb-threatening ischemia (CLTI) has a high mortality and amputation risk even after revascularization. Owing to an aging population the incidence of peripheral arterial disease is rising. However, the current age distribution in patients with CLTI and the impact of age on outcomes remains unclear. For this reason we performed an age-dependent analysis of mortality, morbidity, and amputation-free survival after open surgical revascularization (OSR) and endovascular revascularization therapy (ERT) with identification of risk factors for mortality. Standardized mortality ratios (SMR) were calculated, comparing observed deaths in the study population to expected deaths based on age and gender specific mortality rates of the overall Dutch population. METHODS: Patients revascularized for the first episode of CLTI between 2013 and 2018 were included in this multicenter retrospective cohort study. The cohort was divided into 2 treatment groups (OSR and ERT) who were each stratified in 3 age groups: early age group < 65 years (G1), middle age group 65-74 years (G2), and elderly age group ≥ 75 years (G3). RESULTS: During the study period 274 limbs (43.9%) were treated with OSR and 350 limbs (56.1%) with ERT. The young population (G1) is only a small part of the whole CLTI population, namely for OSR 22% and ERT 18%. The risk profile of the early age group was characterized by male gender and smoking, whereas the elderly age group was characterized by poor arterial runoff, tissue loss, hypertension, hypercholesterolemia, chronic kidney disease, history of heart disease, chronic obstructive pulmonary disease, and cerebrovascular disease. One year amputation rates were similar between the age groups. However, significantly higher one-year mortality rates were observed in patients ≥ 75 years in comparison to the low mortality rates in patients < 75 years (OSR: G3 19.8% vs. G2 7.1% and G1 6.7%, P = 0.006; ERT: G3 30.7% vs. G2 12.7% and G1 7.8%, P = 0.001). The SMR in this elderly group equaled 3.72 after OSR and 4.04 after ERT. Independent risk factors for mortality after OSR were age, hazard ratio (HR) 1.03 (95% confidence interval [CI] 1.01-1.06; P = 0.006), preoperative hemoglobin level (HR 0.79; 95% CI 0.67-0.92; P = 0.003), tissue loss (HR 1.85; 95% CI 1.22-2.79; P = 0.004), cardiac history (HR 1.56; 95% CI 1.06-2.30; P = 0.024), and development of postoperative delirium (HR 2.75; 95% CI 1.61-4.71; P < 0.001). After ERT we identified age, HR 1.06 (95% CI 1.04-1.08; P < 0.001); preoperative hemoglobin level, HR 0.75 (95% CI 0.65-0.87; P < 0.001); tissue loss, HR 1.71 (95% CI 1.15-2.53; P = 0.008); history of chronic obstructive pulmonary disease, HR 1.99 (95% CI 1.43-1.79; P < 0.001); history of cerebrovascular accident (CVA), HR 1.55 (95% CI 1.09-2.21; P = 0.015); the development of postoperative pneumonia, HR 2.27 (95% CI 1.24-4.16; P = 0.008); postoperative acute kidney injury (AKI), HR 2.42 (95% CI 1.29-4.54; P = 0.006); and postoperative CVA, HR 8.17 (95% CI 1.96-34.15; P = 0.004) as risk factors. CONCLUSIONS: The current CLTI population consists mostly of elderly patients and only a small part is younger than 65 years. This shift in the population is important because increasing age is associated with considerable higher one-year mortality rates regardless of the method of revascularization in patients with CLTI. The mortality rates in the elderly group are 3 to 4 times larger than expected in the general population. In relation to the high mortality of the elderly patient, we assume that interventions to prevent postoperative delirium and correct preoperative anemia may be warranted as they appear to be independent risk factors for mortality.

Near infrared spectroscopy to evaluate the effect of a hybrid exercise programme on peripheral muscle metabolism in patients with intermittent claudication: an exploratory PROSECO-IC sub study.

Intermittent claudication (IC) is characterized by decreased blood flow and oxygen delivery to the lower-limb muscles, resulting in pain and impaired functional capacity. This study evaluated the effects of a 12-week hybrid walking intervention on muscle oxygenation and functional capacity in 38 patients with IC (Rutherford I-III). Functional capacity was evaluated by means of two different treadmill test protocols and a six-minute walk test (6MWT). Muscle oxygenation was assessed during the treadmill tests using near-infrared spectroscopy. After the intervention, maximal walking distance was significantly increased (p < 0.001) during the progressive maximal treadmill test (mean (SD): +155 (SD 177) metres) and 6MWT (+18 (SD 29) metres) metres, with concomitant improvements in muscle oxygenation measures. Deoxygenation was slower during the progressive maximal test (p < 0.001) and reoxygenation was faster during recovery (p = 0.045). During the more submaximal test, oxygenated haemoglobin was better preserved (p = 0.040). Slower deoxygenation was more pronounced in the high responders of the progressive maximal treadmill test (p = 0.002). The findings suggest that preserved oxygen availability and slower deoxygenation during exercise could partly explain the improvements in functional capacity.

A systematic review of preclinical data regarding commercial silver-coated vascular grafts.

OBJECTIVE: Vascular graft infection (VGI) is a serious complication with high mortality and morbidity rates. Several measures could be taken to decrease this risk, including the use of silver-containing vascular grafts. However, to date, no clinical advantages have been reported. This study reviews the outcome of preclinical studies focusing on the role of commercially available silver-coated grafts in the prevention of VGI. METHODS: A systematic review was performed with a focus on the preclinical role of commercially available silver-coated vascular grafts in the prevention and treatment of VGI. A comprehensive search was conducted in Medline, Embase, and Web of Science. RESULTS: Nine in vitro and five in vivo studies were included. Two commercial grafts were used (INTERGARD SILVER and Silver Graft). In vitro studies used both gram-positive and gram-negative strains. A positive antimicrobial effect was observed in seven of nine studies (77.8%). A delayed antifungal effect against Candida species was observed in vitro, but disappeared when adding serum proteins. In vivo studies witnessed a microbicidal effect in two out of five studies (40%), but only tested a single causative pathogen (ie, Staphylococcus aureus). CONCLUSIONS: Both in vitro and in vivo studies demonstrated conflicting and mixed results concerning the antimicrobial efficacy of commercially available silver-containing grafts in the prevention of VGI. In general, the study setup was heterogeneous in the different articles. Given the lack of convincing preclinical evidence and their poor performance in clinical studies, more data are needed at this time to guide the appropriate use of silver grafts.

The Use of Near Infrared Spectroscopy to Evaluate the Effect of Exercise on Peripheral Muscle Oxygenation in Patients with Lower Extremity Artery Disease: A Systematic Review.

OBJECTIVE: Near infrared spectroscopy (NIRS) has been suggested as a new diagnostic tool in patients with lower extremity artery disease (LEAD). The aim of this systematic review was to summarise the impact of exercise therapy on lower limb muscle oxygenation, evaluated by NIRS, in patients with LEAD, and to give an overview on NIRS instruments and methodology. DATA SOURCES: MEDLINE and Embase. REVIEW METHODS: A systematic search was conducted in MEDLINE and Embase, from the earliest date available until 16 March 2020, to identify peer reviewed studies involving the use of NIRS in the evaluation of exercise training on muscle oxygenation in patients with LEAD. Primary outcomes were NIRS derived variables during treadmill exercise. Effect sizes were calculated as standardised mean differences. Assessment of methodological quality was done using a combined checklist from the Cochrane bias and the quality assessment tool for before and after studies without a control group. RESULTS: Eleven original trials were included involving 16 exercise groups and four control groups. Tissue saturation index (TSI) at rest remained unchanged following the exercise interventions. Exercise training increased time to minimum TSI during exercise (range effect sizes: +0.172 to +0.927). In addition, exercise training led to a faster recovery to half and full TSI rest values in most intervention groups (range effect sizes -0.046 to -0.558 and -0.269 to -0.665, respectively). Finally, NIRS data reproducibility and analytic methods were under reported in the included studies. CONCLUSION: The available data suggest that exercise training improves de-oxygenation and re-oxygenation patterns, as measured with NIRS, in patients with LEAD. Whereas NIRS is a promising tool in the evaluation of LEAD, the low number of randomised controlled trials, as well as large heterogeneity in NIRS assessment methods, outcome measures, and instrumentation, warrants more research to better understand the role of muscle oxygenation associated with exercise induced improvements in walking capacity.

Pre-clinical in vivo Models of Vascular Graft Coating in the Prevention of Vascular Graft Infection: A Systematic Review.

OBJECTIVE: Vascular graft infection (VGI) remains an important complication with a high mortality and morbidity rate. Currently, studies focusing on the role of vascular graft coatings in the prevention of VGI are scarce. Therefore, the aims of this study were to survey and summarise key features of pre-clinical in vivo models that have been used to investigate coating strategies to prevent VGI and to set up an ideal model that can be used in future preclinical research. DATA SOURCES: A systematic review was conducted in accordance with the Preferred reporting items for Systematic Reviews and Meta-Analysis guidelines. A comprehensive search was performed in MEDLINE (PubMed), Embase, and Web of Science. REVIEW METHODS: For each database, a specific search strategy was developed. Quality was assessed with the Toxicological data Reliability Assessment Tool (ToxRTool). The type of animal model, graft, coating, and pathogen were summarised. The outcome assessment in each study was evaluated. RESULTS: In total, 4 667 studies were identified, of which 94 papers focusing on in vivo testing were included. Staphylococcus aureus was the organism most used (n = 65; 67.7%). Most of the graft types were polyester grafts. Rifampicin was the most frequently used antibiotic coating (n = 43, 48.3%). In the outcome assessment, most studies mentioned colony forming unit count (n = 88; 91.7%) and clinical outcome (n = 72; 75%). According to the ToxRTool, 21 (22.3%, n = 21/94) studies were considered to be not reliable. CONCLUSION: Currently published in vivo models are very miscellaneous. More attention should be paid to the methodology of these pre-clinical reports when transferring novel graft coatings into clinical practice. Variables used in pre-clinical reports (bacterial strain, duration of activity coating) do not correspond well to current clinical studies. Based on the results of this review, a proposal for a complete and comprehensive set up for pre-clinical invivo testing of anti-infectious properties of vascular graft coatings was defined.

Quality Indicators in Vascular Surgery: Toward a National Consensus on 20 Quality Indicators in Belgium.

BACKGROUND: The aim of the present study is to develop relevant quality indicators (QI) to monitor and improve quality of care in vascular surgery. METHODS: The Delphi method was used to incorporate expert opinion to reach consensus on a set of QI. A national expert panel consisting of 52 vascular surgeons was installed on a voluntary basis and endorsed by the Belgian Society of Vascular Surgery and the Flemish Hospital Network KU Leuven. A task force team consisting of 12 surgeons was created to serve as a delegation of the expert panel to discuss and filter the obtained data from the different Delphi rounds. RESULTS: A total of 3 Delphi rounds were needed to reach consensus on a set of 20 QI. Each QI had a content validity index (using a 7-point Likert scale), a feasibility index, and a target level. Twelve outcome indicators and 8 process indicators on several vascular topics were selected: overall for all vascular treatments (n = 1), arterial occlusive disease in general (n = 3), arterial occlusive disease of the lower limbs (n = 4), arterial occlusive disease of the carotid arteries (n = 5), arterial aneurysm disease in general (n = 2), arterial aneurysm disease with endovascular treatment (n = 1), and venous disease (n = 4). CONCLUSIONS: This resulted in the successful identification of 20 validated and relevant vascular QI, focusing on arterial occlusive disease, arterial aneurysm disease, and venous disease. The next step in this project will be the performance of an implementation study.

Predictive Factors of Operative Need in Medically Managed Type B Aortic Dissections.

BACKGROUND: Aneurysmal degeneration of medically managed type B aortic dissection (TBAD) can be a life-threatening condition. Preventive thoracic endovascular aorta repair (TEVAR) in patients at risk could potentially be beneficial. The aim of this study was to examine the predictors for late aneurysmal dilatation after TBAD. METHODS: A retrospective study was conducted on 82 patients with medically managed acute TBAD for a minimum of 14 days. Relevant demographic, biochemical, and radiographic variables at presentation were studied. The aortic dissection risk calculator tool developed by Sailer et al., predicting the risk of adverse events after aortic dissection based on demographic and radiographic variables at presentation, was tested retrospectively. RESULTS: With a median follow-up of 36 months (range 13-68), 25 (30.5%) patients underwent surgery (92% TEVAR). A larger initial aortic and false lumen diameter as well as a greater distal extension of the dissection was associated with higher need for surgery (respectively, P = 0.003, P = 0.004, and P = 0.001). We observed higher growth rates of maximum aortic diameter in patients with a greater distal extension of the dissection, larger false lumen diameters and false lumen outflow, and entry tears located at the inner aortic arch (respectively, P = 0.001, P = 0.005, P = 0.001 and P = 0.014). No significant correlations could be found for the risks provided by the calculator tool. CONCLUSIONS: The initial maximum aortic diameter of TBAD is a key predictor for aortic growth. Furthermore, the distal extension of the dissection also seems to play an important role in late aneurysmal degeneration. However, we were not able to confirm the added value of the risk calculator tool in our study group.

Late hematogenous seeding and infection of a femoropopliteal Omniflow II bypass.

INTRODUCTION: Omniflow II is promoted as an infection-resistant vascular graft. It is used to treat vascular graft infection; nevertheless, early graft infection has been reported.Report: A 71-year-old patient was treated with an Omniflow II bypass for a non-healing diabetic foot ulcer. Seven months postoperatively, late infection occurred secondary to hematogenous spread from a persistent foot infection. CONCLUSION: We report on the first case of late infection of an Omniflow II vascular graft caused by hematogenous spread. Despite promising results of the Omniflow II graft in the treatment of vascular graft infection, late infection may not be avoided.

Factors predicting long-term outcomes of percutaneous angioplasty and stenting of the superior mesenteric artery for chronic mesenteric ischemia.

Background: To analyse the long-term outcomes of percutaneous angioplasty and stenting of the superior mesenteric artery (SMA) in the treatment of chronic mesenteric ischemia (CMI), and to assess predictive factors for a better clinical outcome. Patients and methods: Retrospective analysis of 76 consecutive patients, treated percutaneously for CMI between January 1999 and January 2018 and followed up until the end of 2018. Patients' pre-, peri- and post-interventional clinical and radiological data were gathered from the institutional electronic medical records. The Kaplan Meier method with log rank test or the Cox model were used to analyse overall survival; the cumulative incidence function with Pepe and Mori test or the Fine and Grey model were used to analyse relapse-free survival, considering death as a competing event. Results: Seventy-six consecutive patients with a mean age of 72 years were included in the study. Catheter-angiography revealed an ostial or non-ostial >90% stenosis in n=23 (29.7%) and n=53 (69.7%) of included patients, respectively. Immediate clinical success was achieved in n=68 (89.5%), and procedural complications were observed in n=13 (17.1%) patients. Long-term follow-up revealed relapse of symptoms in n=21 (28.8%) patients, and overall survival estimates are 81.8%, 57.0% and 28.2% after two, five and ten years of follow-up, respectively. A trend towards longer relapse-free survival was found in the circumferential stenosis group (78.2% at five years) compared with the non-circumferential stenosis group (55.5%) (P=0.063). Conclusions: Angioplasty and stenting of the SMA for CMI is relatively safe and effective despite a substantial number of patients experiencing clinical relapse over time. Patients with focal, circumferential stenosis might have longer relapse-free survival than patients with non-circumferential stenosis.

The discovery of the lymphatic system in the seventeenth century. Part VI: the microscopic discovery of the subtle anatomy.

The discovery of chyle and lymph vessels had furthered the dream of understanding the body's structure and functions. Initially it was thought that chyle was sucked from the intestines through the open mouths of chyle vessels, and that lymph vessels were side branches of arterial end branches. In the second half of the 17th century, microscopy became an adjuvant for research into the subtle anatomy of the lymphatic system. In the present paper, we will focus on its initial use for the study of the structure and function of chyle and lymph vessels, and lymph glands.

The discovery of the lymphatic system in the 17th century. Part VII: the rise of vascular injection.

In the second half of the seventeenth century, vascular injection was introduced in anatomy for the study of the mechanism of secretion of bodily fluids, a phenomenon into which the lymphatic system plays an important role. Injection became a routine procedure in the second half of the seventeenth century. Reinier de Graaf developed an appropriate syringe to inject liquid into minuscule tubules. He was the first to observe that water injected into seminiferous tubules was partially repelled by transudation to be absorbed by neighbouring lymph vessels. He also injected lymph vessels in and around the uterus and ovaries. His study friend Johannes Swammerdam developed a coloured hardening wax and Ruysch injected coloured hardening wax into vessels and ducts of lymph nodes and excretory glands. Ruysch introduced combined injection - corrosion procedures which resulted in delicate structures, including capillaries. He denied the presence of glandular structures in organs as described by Malpighi, and made blood vessels inclusive lymph vessels agents instead of aids to fluid secretion. His ideas resulted in the concept of the body being completely vascular, a theory which became commonplace in Dutch medical circles. Antony Nuck, the professor in medicine at the Leiden University, injected an amalgam of quicksilver and tin for further evaluation of the lymphatic system. He thought that lymph vessels originated from distal arteries and sustained that the shape of pores in these arteries determined the mechanisms of secretion in secretory glands and in lymph glands. He introduced lymphography.