Protocol for an independent patient data meta-analysis of prophylactic mesh placement for incisional hernia prevention after abdominal aortic aneurysm surgery: a collaborative European Hernia Society project (I-PREVENT-AAA)

INTRODUCTION

Incisional hernia (IH) is a prevalent and potentially dangerous complication of abdominal surgery, especially in high-risk groups. Mesh reinforcement of the abdominal wall has been studied as a potential intervention to prevent IHs. Randomised controlled trials (RCTs) have demonstrated that prophylactic mesh reinforcement after abdominal surgery, in general, is effective and safe. In patients with abdominal aortic aneurysm (AAA), prophylactic mesh reinforcement after open repair has not yet been recommended in official guidelines, because of relatively small sample sizes in individual trials. Furthermore, the identification of subgroups that benefit most from prophylactic mesh placement requires larger patient numbers. Our primary aim is to evaluate the efficacy and effectiveness of the use of a prophylactic mesh after open AAA surgery to prevent IH by performing an individual patient data meta-analysis (IPDMA). Secondary aims include the evaluation of postoperative complications, pain and quality of life, and the identification of potential subgroups that benefit most from prophylactic mesh reinforcement.

METHODS AND ANALYSIS

We will conduct a systematic review to identify RCTs that study prophylactic mesh placement after open AAA surgery. Cochrane Central Register of Controlled Trials, MEDLINE Ovid, Embase, Web of Science Core Collection and Google Scholar will be searched from the date of inception onwards. RCTs must directly compare primary sutured closure with mesh closure in adult patients who undergo open AAA surgery. Lead authors of eligible studies will be asked to share individual participant data (IPD). The risk of bias (ROB) for each included study will be assessed using the Cochrane ROB tool. An IPDMA will be performed to evaluate the efficacy, with the IH rate as the primary outcome. Any signs of heterogeneity will be evaluated by Forest plots. Time-to-event analyses are performed using Cox regression analysis to evaluate risk factors.

ETHICS AND DISSEMINATION

No new data will be collected in this study. We will adhere to institutional, national and international regulations regarding the secure and confidential sharing of IPD, addressing ethics as indicated. We will disseminate findings via international conferences, open-source publications in peer-reviewed journals and summaries posted online.

PROSPERO REGISTRATION NUMBER

CRD42022347881.

Evaluation of Hemodynamic Properties After Chimney and Fenestrated Endovascular Aneurysm Repair

BACKGROUND

Fenestrated (FEVAR) and chimney (ChEVAR) endovascular aortic repair have been applied in anatomically suitable complex aortic aneurysms. However, local hemodynamic changes may occur after repair. This study aimed to compare FEVAR's and ChEVAR's hemodynamic properties, focusing on visceral arteries.

METHODS

Preoperative and postoperative computed tomography angiographies have been used to reconstruct patient-based models. Data of 3 patients, for each modality, were analyzed. Following geometric reconstruction, computational fluid dynamics simulations were used to extract near-wall and intravascular hemodynamic indicators, such as pressure drops, velocity, wall shear stress, time averaged wall shear stress, oscillatory shear index, relative residence time, and local normalized helicity.

RESULTS

An overall improvement in hemodynamics was detected after repair, with either technique. Preoperatively, a disturbed prothrombotic wall shear stress profile was recorded in several zones of the sac. The local normalized helicity results showed a better organization of the helical structures at postoperative setting, decreasing thrombus formation, with both modalities. Similarly, time averaged wall shear stress increased and oscillatory shear index decreased postoperatively, signaling nondisturbed blood flow. The relative residence time was locally reduced. The flow in visceral arteries tended to be more streamlined in ChEVAR, compared to evident recirculation regions at renal and superior mesenteric artery fenestrations (P = 0.06).

CONCLUSIONS

ChEVAR and FEVAR seem to improve hemodynamics toward normal values with a reduction of recirculation zones in the main graft and aortic branches. Visceral artery flow comparison revealed that ChEVAR tended to present lower recirculation regions at parallel grafts' entries while FEVAR showed less intense flow regurgitation in visceral stents.

Transition from Open Repair to Endovascular Aneurysm Repair for Rupture Aortic Aneurysms throughout a 16-Year Period of Time in a Single Tertiary Center

BACKGROUND

Endovascular aneurysm repair (EVAR) is recommended as the first option for both elective and ruptured abdominal aortic aneurysms (rAAAs) with suitable anatomy. The aim of this study was to evaluate the outcomes of the gradual adoption of ruptured EVAR (rEVAR) as first option in the management of rAAAs in a reference tertiary center over a 16 year-period.

METHODS

A retrospective analysis of prospectively collected clinical data was undertaken, including all patients that were treated for rAAA infrarenal or juxtarenal either with open surgical repair (OSR) or EVAR from 2006-2023. Three periods were identified and analyzed: Initial (2006-2011); intermediate (2012-2017); and current (2018-2023). The primary outcomes were the 30-day mortality rate in relation to the changing pattern of treatment. Secondary outcomes were re-intervention and mortality during the follow up period.

RESULTS

Two hundred patients were treated for rAAA; 52% by endovascular means [EVAR (94), Ch-EVAR (9), and branched endovascular aneurysm repair (1)] and 48% by OSR (96). In the initial period, 61 patients were treated for rAAA (21% EVAR vs. 79% OSR), 68 in intermediate patients (47% EVAR vs. 53% OSR), and 71 in current period (83% EVAR vs. 17% OSR). Only in the current period juxta -renal rAAAs were treated by endovascular means (14%). The 30-day mortality rate was 46% in initial period (31% for EVAR vs. 50% for OSR), 64% in second period (46% in EVAR vs. 80% for OSR), and 35% in third period (25% for EVAR vs. 83% for OSR). The mean follow up did not differ between the groups, (EVAR 28.3 ± 2 months, vs. OSR 33.1 ± 3 months, P = 0.56). The survival rate did not differ between the groups; in rEVAR was 82% (SE 5%), 74% (SE 6%), 68% (SE 6.5%), and 63% (SE 7.7%) at 12, 24, 36, and 48 months, respectively, and in OSR was 76% (SE 7%), 66% (SE 8%), and 56% (SE 9.5%) at 6, 24, and 48 months, respectively (P = 0.544).

CONCLUSIONS

Through a 16-year period, the implementation of EVAR as treatment of choice for rAAAs over OSR resulted in a noticeable reduction in the 30-day mortality. rEVAR was feasible in over 80% of rAAA patients.

Risk Factors for Postdischarge Major Thromboembolism and Mortality in Hospitalized Patients with COVID-19 with Cardiovascular Comorbidities: Insights from the CORE-19 Registry

BACKGROUND

 Coronavirus disease 2019 (COVID-19) is associated with venous and arterial thromboembolism (VTE and ATE) and all-cause mortality (ACM) in hospitalized patients. High-quality data are needed on postdischarge outcomes in patients with cardiovascular disease.

OBJECTIVES

 To analyze outcomes and identify risk factors for ATE, VTE, and ACM in a high-risk subgroup of hospitalized COVID-19 patients with baseline cardiovascular disease.

METHODS

 We investigated postdischarge rates and associated risk factors of ATE, VTE, and ACM in 608 hospitalized COVID-19 patients with coronary artery disease, carotid artery stenosis (CAS), peripheral arterial disease (PAD), or ischemic stroke.

RESULTS

 Through 90 days postdischarge, outcome rates were: ATE 27.3% (10.2% myocardial infarction, 10.1% ischemic stroke, 13.2% systemic embolism, 12.7% major adverse limb event); VTE 6.9% (4.1% deep vein thrombosis, 3.6% pulmonary embolism); composite of ATE, VTE, or ACM 35.2% (214/608). Multivariate analysis showed significant association between this composite endpoint and age >75 years (odds ratio [OR]: 1.90, 95% confidence interval [CI]: 1.22-2.94, p = 0.004), PAD (OR: 3.23, 95% CI: 1.80-5.81, p ≤ 0.0001), CAS (OR: 1.74, 95% CI: 1.11-2.75, p = 0.017), congestive heart failure (CHF) (OR: 1.84, 95% CI: 1.02-3.35, p = 0.044), previous VTE (OR: 3.08, 95% CI: 1.75-5.42, p < 0.0001), and intensive care unit (ICU) admission (OR: 2.93, 95% CI: 1.81-4.75, p < 0.0001).

CONCLUSION

 COVID-19 inpatients with cardiovascular disease experience high rates of ATE, VTE, or ACM through 90 days postdischarge. Age >75 years, PAD, CAS, CHF, previous VTE, and ICU admission are independent risk factors.

Predictors of 30-Day Postoperative Outcome after Elective Endovascular Abdominal Aortic Aneurysm Repair: A Tertiary Referral Center Experience

BACKGROUND

We evaluated the 30-day postoperative outcome after elective endovascular aneurysm repair (EVAR) and the possible predictors for the 30-day postoperative outcome.

MATERIALS

Demographics, medical history, laboratory values, intensive care unit (ICU) admission and 30-day complications classified as major (major adverse cardiovascular events (MACEs), acute kidney injury (AKI) and death of any cause) and minor (postimplantation syndrome (PIS), postoperative delirium (POD), urinary tract infection (UTI) and technical graft failure) were documented (March 2016 to February 2019).

RESULTS

We included 322 patients. The majority were managed under general anesthesia (83%) with femoral cutdown (98.1%). Overall, 121 (37.5%) complications, mostly minor (n = 103, 31.9%), were recorded. In total, 11 patients (3.4%) developed MACEs, 5 (1.6%) experienced AKI and 2 (0.6%) died in the ICU. Moreover, 77 patients (23.9%) suffered from PIS, 11 from POD, 11 from UTI and 4 from technical graft failure. The multivariate logistic regression analysis revealed that aneurysm diameter (p = 0.01) and past smoking (p = 0.003) were predictors for complications. PAD was an independent predictor of MACEs (p = 0.003), preoperative neutrophil to lymphocyte ratio (NLR) of AKI (p = 0.003) and past smoking of PIS (p = 0.008), respectively.

CONCLUSIONS

Our study showed that the 30-day morbidity after EVAR exceeded 35%. However, the majority of complications were minor, and the associated mortality was low. Aneurysm diameter and past smoking were independent predictors for postoperative outcome.

Appraisal of the Clinical Practice Guidelines for the Use of Antithrombotic Therapy in Elective Spinal Procedures: Do We AGREE (II)?

The perioperative management of patients medicated with antithrombotic agents who require elective spinal surgery is extremely challenging because of the increased risk of surgical bleeding and the concurrent need to minimize the thromboembolic risk. The aims of the present systematic review are to: (1) identify clinical practice guidelines (CPGs) and recommendations (CPRs) on this topic and (2) assess their methodological quality and reporting clarity. An electronic systematic search of the English Medical Literature up to January 31, 2021 was conducted using PubMed, Google Scholar, and Scopus. Two raters assessed the methodological quality and reporting clarity of the gathered CPGs and CPRs using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) tool. The agreement between the two raters was assessed using Cohen's kappa. Of the initially gathered 38 CPGs and CPRs, 16 fulfilled our eligibility criteria and were evaluated using the AGREE II instrument. The reports published by "Narouze 2018" and "Fleisher 2014" were scored as being of "high-quality" and having an adequate interrater agreement (Cohen's kappa ≥0.60). Overall, the AGREE II domains of "clarity of presentation" and "scope and purpose" yielded the highest scores (100%), whereas the domain "stakeholder involvement" scored the lowest score (48.5%). The perioperative management of antiplatelet and anticoagulant agents in elective spine surgery may be challenging. Because of the lack of high-quality data in this field, uncertainty remains regarding the optimal practices to balance the risk of thromboembolism against that of bleeding.

Complete Vascular Replacement of the Infrarenal Inferior Vena Cava and Abdominal Aorta during Post-Chemotherapy Retroperitoneal Lymph Node Dissection for a Non-Seminomatous Germ Cell Tumor

Testicular germ cell tumors (TGCTs) are the leading cause of cancer-related death in males between the ages of 20 and 40. In the advanced stages, the combination of cisplatin-based chemotherapy and surgical excision of the remaining tumor can cure many of these patients. Vascular procedures may be required during retroperitoneal lymph node dissection (RPLND) in order to achieve the complete excision of all residual retroperitoneal masses. Careful assessment of pre-operative imaging and the identification of patients who could benefit from additional procedures are important for minimizing peri- and postoperative complications. We report on a case of a 27-year-old patient with non-seminomatous TGCT, who successfully underwent post-chemotherapy RPLND with additional infrarenal inferior vena cava (IVC) and complete abdominal aorta replacement using synthetic grafts.

Conical Aortic Neck as a Predictor of Outcome after Endovascular Aneurysm Exclusion: Midterm Results

BACKGROUND

Conical neck may affect endovascular aneurysm repair (EVAR) outcomes. The aim of this study was to present EVAR neck adverse events [endoleak type Ia (ET Ia) and graft migration], in patients with conical neck morphology compared to patients with non-conical necks. An additional analysis of the factors that may affect neck adverse events in patients with conical necks, during the first postoperative year, was executed.

METHODS

A retrospective analysis of prospective data was conducted, including patients that underwent elective EVAR, between 2017 and 2019. All patients completed the clinical and imaging follow-up of the initial 12 months. Regarding imaging, all cases underwent computed tomography angiography (CTA), preoperatively, at the 1st and 12th month of follow-up. Preoperative and postoperative aneurysm anatomic characteristics (supra-renal and infra-renal aortic diameters, aneurysm diameter, neck angle, thrombus, and calcification) were recorded. Proximal neck was defined as the infrarenal aortic segment, with a diameter less than 30 mm. Conical neck was any neck with a diameter increase ≥2 mm per cm of length (from outer-to-outer aortic wall). The proximal 15 mm of the neck length were considered the zone of endograft sealing. Migration was any ≥10 mm caudal movement of the endograft, relative to its position detected at the CTA of the first month. Neck adverse events were defined as the composite event of ET Ia and migration.

RESULTS

The cohort included 150 patients; 66 (44%) presented conical neck morphology. No significant difference was detected regarding the preoperative anatomic characteristics between the conical and non-conical groups. Only distal (15 mm) neck diameter was wider in the conical group (P < 0.001). Supra-renal active fixation was used in 63.3% of the total cohort; 59.5% in patients with non-conical necks and 68.2% in patients with conical morphology (P = 0.275). Graft oversizing was 18.2% and 18.7% in the non-conical and conical group, respectively (P = 0.248). Oversizing >20% was equal between groups [37.8% vs. 33.3%% (P = 0.608) while oversizing ≥30% was more common among patients with conical necks (3.5% vs. 10.6%, P < 0.001, 3.2 odds ratio, 95% confidence interval: 0.79, 12.91). Regarding ET Ia and migration, no difference was recorded between the groups. In a subanalysis among patients with conical necks, a lower graft migration rate was detected among patients with higher oversizing rate (P = 0.037).

CONCLUSIONS

EVAR may offer similarly good midterm outcomes in patients with conical and non-conical neck anatomy. An oversizing to the higher suggested rate may be preventive of graft migration during the first postoperative year in necks with conical morphology. Aggressive oversizing (>20%) do not offer any benefit regarding the prevention of adverse events among patients with conical necks.

Risk factors and adverse events related to supra- and infra-renal aortic dilation at twelve months after endovascular abdominal aortic aneurysm repair

BACKGROUND

Aortic remodeling and its effect on adverse events after endovascular abdominal aneurysm repair (EVAR) remain under investigation. This study aimed to assess aortic diameter alterations after EVAR, related risk factors and consequences to proximal sealing at 12 months.

METHODS

A single-center retrospective analysis of consecutive EVAR patients was undertaken. All patients underwent computed tomography angiography, preoperatively, at 1^st and 12^th month. The infrarenal diameter was measured just below the inferior renal artery, at 7 mm and 15 mm while the suprarenal, just above the superior renal artery (SRA), superior mesenteric artery (SMA) and just below the celiac trunk. Neck-related adverse events included migration and endoleak Ia.

RESULTS

A hundred fifty patients were included. At 1^st month, no significant diameter alteration was recorded at any level. At 12^th month, all infra-renal diameters increased (P<0.001) and diameters at SRA and SMA also augmented (P=0.024 and P=0.007, respectively). Neck diameter >29 mm, supra-renal fixation and oversizing >20% were associated to dilation at 12^th month. Neck adverse events were related to diameter alterations below the inferior renal artery (P=0.017), SRA (P=0.007) and SMA (P=0.05).

CONCLUSIONS

During the 12-month follow-up, aortic dilation may be detected from the supra-renal aorta to the total neck length. Neck dilation may be attributed to large neck diameter, supra-renal fixation, and aggressive oversizing. Neck-related adverse events are more common in patients with aortic dilation at 12 months.

COVID-19 related peripheral arterial thrombotic events in intensive care unit and non-intensive care unit patients: A retrospective case series

OBJECTIVES

COVID-19 associated arterial thrombosis has been attributed to multiple inflammation and coagulation mechanisms. The aim of this study was to report the experience of a tertiary center on COVID-19 patients managed for acute peripheral arterial thrombosis.

METHODS

A single-center case series was conducted, including retrospectively collected data from all COVID-19 patients presenting arterial thrombosis, from March 2020 to February 2022. Intensive care unit (ICU) and non-ICU cases were included. The primary outcomes were mortality, successful revascularization, and amputation at 30 days.

RESULTS

Twenty patients presented peripheral arterial thrombosis (90% males, mean age 65 years (16-82 years)). Eighteen were diagnosed with the Delta variant and none was previously vaccinated. All cases presented acute lower limb ischemia; in 20% with bilateral involvement. Nine patients were hospitalized in the ward while 11 in the ICU. From the non-ICU cases, five presented Rutherford IIb and four cases, Rutherford's IIa ischemia. Six cases underwent revascularization (67%). Two of them were finally amputated (33%) and two died during hospitalization (33%). Two revascularizations were considered successful (33%). The ICU group presented mainly with Rutherford's III ischemia (54.5%). The mortality in the ICU cohort was 72.7%. Only one patient underwent successful revascularization and two were amputated in this subgroup. Early mortality was 50% for the total cohort while the type of management was not related to mortality.

CONCLUSIONS

Covid-19 related arterial thrombosis in non-vaccinated population is associated with 50% early mortality; increased up to 72% in the ICU patients. The amputation rate was 20% while only 40% of the revascularizations were considered successful.

Editor's Choice - Endovascular Aneurysm Repair in High Risk Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

To investigate outcomes of endovascular aneurysm repair (EVAR) in high risk patients.

METHODS

Bibliographic sources (MEDLINE, EMBASE, CINAHL, and CENTRAL) were searched using combinations of thesaurus and free text terms. The review protocol was registered in PROSPERO (CRD42021287207) and reported according to PRISMA 2020. Pooled estimates were calculated using odds ratio (OR) or hazard ratio (HR) and 95% confidence interval (CI) applying the Mantel-Haenszel or inverse variance method. EVAR peri-operative mortality in high risk patients over time was examined with mixed effects meta-regression. The GRADE framework was used to rate the certainty of evidence.

RESULTS

The pooled peri-operative mortality in 18 416 high risk patients who underwent EVAR was 3% (95% CI 2.3 - 4%) and has significantly reduced over time (year of publication p = .003; median study point p = .023). The peri-operative mortality was significantly lower in high risk patients treated with EVAR compared with open repair (OR 0.64; 95% CI 0.45 - 0.92), but no significant difference was found in overall (HR 1.06; 95% CI 0.76 - 1.49) or aneurysm related mortality (HR 0.57; 95% CI 0.21 - 1.55). No significant difference was found in overall mortality between high risk patients treated with EVAR vs. no intervention (HR 0.42; 95% CI 0.14 - 1.26), but the aneurysm related mortality was significantly lower in the former (HR 0.30; 95% CI 0.14 - 0.63). The peri-operative mortality was higher in high risk than normal risk patients treated with EVAR (OR 2.33; 95% CI 1.75 - 3.10), as was the overall mortality (HR 3.50; 95% CI 2.55 - 4.80). The certainty of evidence was very low for EVAR vs. open surgery or no intervention and low for high vs. normal risk patients.

CONCLUSION

The EVAR peri-operative mortality in high risk patients has improved over time. Even though the aneurysm related mortality of EVAR is lower compared with no intervention, EVAR may confer no overall survival benefit.

Update in combined musculoskeletal and vascular injuries of the extremities

Combined musculoskeletal and vascular injuries of the extremities are conditions in which a multidisciplinary approach is a sine qua non to ensure life initially and limb viability secondarily. Vascular injuries as part of musculoskeletal trauma are usually the result of the release of a high energy load in the wound site so that the prognosis is determined by the degree of soft-tissue damage, duration of limb ischemia, patient’s medical status and presence of associated injuries. The management of these injuries is challenging and requires a specific algorithm of action, because they are usually characterized by increased morbidity, amputation rate, infection, neurological and functional deficits, and they could be life threatening. Although vascular injuries are rare and occur either isolated or in the context of major combined musculoskeletal trauma, the high index of suspicion, imaging control, and timely referral of the patient to organized trauma centers ensure the best functional outcome of the extremity in such challenging cases. Even after a successful initial treatment of a combined trauma pattern, long-term follow-up is crucial to prevent and detect early possible complications. The purpose of this manuscript is to provide an update on diagnosis and treatment of combined musculoskeletal and vascular injuries of the extremities, from an orthopedic point of view.

Characteristics and outcomes of cancer patients who develop pulmonary embolism: A cross‑sectional study

Pulmonary embolism (PE), along with deep vein thrombosis, are collectively known as venous thromboembolism (VTE). Predisposing factors for PE include post-operative conditions, pregnancy, cancer and an advanced age; of note, a number of genetic mutations have been found to be associated with an increased risk of PE. The association between cancer and VTE is well-established, and cancer patients present a higher risk of a thrombotic event compared to the general population. In addition, PE is a significant cause of morbidity and mortality among cancer patients. The aim of the present study was to illustrate the clinical characteristics, laboratory findings, radiology features and outcomes of cancer patients who developed PE, collected from an anticancer hospital. For this purpose, adult cancer patients diagnosed with PE by imaging with computed tomography pulmonary angiography were enrolled. The following data were recorded: Demographics, comorbidities, type of cancer, time interval between cancer diagnosis and PE occurrence, the type of therapy received and the presence of metastases, clinical signs and symptoms, predisposing factors for PE development, laboratory data, radiological findings, electrocardiography findings, and the type of therapy received for PE and outcomes in a follow-up period of 6 months. In total, 60 cancer patients were enrolled. The majority of the cancer patients were males. The most common type of cancer observed was lung cancer. The majority of cases of PE occurred within the first year from the time of cancer diagnosis, while the majority of patients had already developed metastases. In addition, the majority of cancer patients had received chemotherapy over the past month, while they were not receiving anticoagulants and had central obstruction. A large proportion of patients had asymptomatic PE. The in-hospital mortality rate was 13.3% and no relapse or mortality were observed during the follow-up period. The present study demonstrates that elevated levels of lactic acid and an increased platelet count, as well as low serum levels of carcinoembryonic antigen, albumin and D-dimer, may be potential biomarkers for asymptomatic PE among cancer patients.

Management of Ascending Aorta and Aortic Arch: Similarities and Differences Among Cardiovascular Guidelines

BACKGROUND

Ascending aorta and aortic arch diseases have an increasing interest among cardiovascular specialists regarding diagnosis and management. Innovations in endovascular surgery and evolution of open surgery have extended the indications for treatment in patients previously considered unfit for surgery. The aim of this systematic review of the literature was to present and analyze current cardiovascular guidelines for overlap and differences in their recommendations regarding ascending aorta and aortic arch diseases and the assessment of evidence.

METHODS

The English medical literature was searched using the MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases from January 2009 to December 2020. Recommendations on selected topics were analyzed, including issues from definitions and diagnosis (imaging and biomarkers) and indications for treatment to management, including surgical techniques, of the most important ascending aorta and aortic arch diseases.

RESULTS

The initial search identified 2414 articles. After exclusion of duplicate or inappropriate articles, the final analysis included 5 articles from multidisciplinary, cardiovascular societies published between 2010 and 2019. The definition of non-A-non-B aortic dissection is lacking from most of the guidelines. There is a disagreement regarding the class of recommendation and level of evidence for the diameter of ascending aorta as an indication. The indication for treatment of aortic disease may be individualized in specific cases while the growth rate may also affect the decision making. The role of endovascular techniques has not been established in current guidelines except by 1 society. Supportive evidence level in the management of aortic arch diseases remains limited.

CONCLUSION

In current recommendations of cardiovascular societies, the ascending aorta and aortic arch remain a domain of open surgery despite the introduction of endovascular techniques. Recommendations of the included societies are mostly based on expert opinion, and the role of endovascular techniques has been highlighted only from 1 society. The chronological heterogeneity apparent among guidelines and the inconsistency in evidence level should be also acknowledged. More data are needed to develop more solid recommendations for the ascending aorta and aortic arch diseases.

Clinical effect of accessory renal artery coverage after endovascular repair of aneurysms in abdominal and thoracoabdominal aorta

BACKGROUND

The aim of our systematic review and meta-analysis was to assess the effect of accessory renal artery (ARA) coverage on renal function in terms of acute kidney injury (AKI), renal infarction, chronic renal failure (CRF), and mortality in patients undergoing standard endovascular aortic aneurysm repair (EVAR) or endovascular repair of complex aneurysms.

METHODS

An electronic search of the English language medical literature from 2000 to September 2020 was conducted using the MEDLINE, EMBASE, and Cochrane databases with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) method for studies reporting on ARA management in patients undergoing endovascular repair of aneurysms in the abdominal and thoracoabdominal aorta. The patients were divided into two groups: group 1, patients with ARA coverage; and group 2, patients without an ARA or without coverage of the ARA. Each group included two arms, one of patients who had undergone standard EVAR and one of patients who had undergone endovascular treatment of a complex aortic aneurysm. The GRADE (grading of recommendations assessment, development, evaluation) approach was used to evaluate the quality of evidence and summary of the findings. The primary outcomes included the incidence of AKI, renal infarction, CRF, and mortality.

RESULTS

Ten retrospective, nonrandomized, control studies were included in the systematic review reporting on 1014 patients (302 with a covered ARA vs 712 without an ARA or without ARA coverage). In six studies, the mean diameter of the covered ARA was <4 mm (range, 2.7-3.4 mm). The mean follow-up was 22.74 months (range, 1-42 months). In the standard EVAR subgroup, the risk of AKI (odds ratio [OR], 0.72; 95% confidence interval [CI], 0.21-2.51; I² = 0%] in the early period, and CRF (OR, 4.44; 95% CI, 0.46-42.61; I² = 87%) and death (OR, 0.91; 95% CI, 0.36-2.31; I² = 0%) during follow-up were similar between groups 1 and 2. Only the risk of renal infarction was greater in group 1 than in group 2 (OR, 93.3; 95% CI, 1.48-5869; I² = 92%). In the complex aneurysm repair subgroup, the risk of AKI (OR, 1.85; 95% CI, 0.61-5.64; I² = 42%) in early period and CRF (OR, 1.64; 95% CI, 0.88-3.07; I² = not applicable) and death (OR, 3.63; 95% CI, 0.14-96.29; I² = 56%) during follow-up were similar between groups 1 and 2. Only the risk of renal infarction was greater for group 1 compared with group 2 (OR, 8.58; 95% CI, 4.59-16.04; I² = 0%).

CONCLUSIONS

ARA (<4 mm) coverage in patients undergoing standard EVAR or endovascular repair of complex aneurysms is associated with an increased risk of renal infarction. However, we found no clinical effects of ARA coverage on renal function or mortality in early postoperative and follow-up period. Preservation of an ARA >4 mm should be considered.

Modeling and Computational Comparison of the Displacement Forces Exerted between the AFX Unibody Aortic Stent Graft and its Hybrid Combination with a Nitinol-based Proximal Aortic Cuff

BACKGROUND

The bifurcated AFX (Endologix, Inc, Irvine, CA, USA) aortic stent-graft is the sole unibody endograft for the management of Abdominal Aortic Aneurysms (AAA). In order to improve the AFX central sealing and clinical efficacy in challenging cases, a replacement of the central chromium-cobaltium AFX extension with a Nitinol-based proximal aortic cuff has been suggested. Yet, comparative data regarding the hemodynamic performance of this design is missing. Aim of this study was to compare the displacement forces (DF) acting on the hybrid AFX-Endurant design, with the classic AFX and Endurant endografts, in angulated and non-angulated cases based on patient-specific Computational Fluid Dynamics (CFD) simulations.

METHODS

3D endograft models of 11 treated AAA cases were reconstructed from Computed Tomography Angiography (CTA) imaging data: 5 cases of AFX, 3 cases of the combination AFX-Endurant and 3 cases of the classic Endurant design. The DF on the main-body, the iliac limbs, and the entire stent-graft was calculated by processing the velocity and pressure fields generated by pulsatile CFD simulations.

RESULTS

The range of total DF (acting on the whole endograft structure) in the AFX, hybrid AFX-Endurant and Endurant group was 2.5-5.2N, 2.0-5.9N and 1.9-2.9N respectively, with the maximum total DF being lower for Endurant. The DF on the main-body of the classic and hybrid AFX cases were higher than the right and left iliac limbs (2.5-4.9N vs. 0.6-5.3N and 0.7-3.6N respectively). Conversely, the DF on the main-body of the Endurant cases was comparable to the force exerted on the right and left limbs. When separating the cases with respect to their neck angulation, the DF on all endograft parts (main-body, limbs) and on the endograft as a whole were lower for the hybrid AFX-Endurant group compared to the classic AFX and Endurant groups, for cases with almost straight neck.

CONCLUSION

The off-label use of the hybrid AFX-Endurant stent-graft does not seem superior to the conventional AFX or Endurant endografts in angulated cases but was associated with lower DF than AFX or Endurant in non-angulated cases. The clinical value and utility of these findings remain to be elucidated.

Ten-year single center experience in elective standard endovascular abdominal aortic aneurysm repair

BACKGROUND

Endovascular aneurysm repair (EVAR) has become the treatment of choice for abdominal aortic aneurysm (AAA), demonstrating excellent early outcomes. However, EVAR durability has been questioned in the long-term period. The aim of this study was to assess EVAR outcomes in terms of survival and freedom from re-intervention during a long-term period.

METHODS

All consecutive patients being treated, with elective standard EVAR, in a single tertiary center, were included between 2008 and 2018. Outcomes were defined as survival and freedom from re-intervention and were reported using Kaplan-Meyer lifetables. In subgroup analyses, sex, age (threshold at 65 and 80 years), neck diameter>28mm and type of fixation were also analyzed. Type of re-intervention and endoleak type I (ETIa) were also reported.

RESULTS

Five hundred and eight patients (94% males, mean age 72±7.3, mean AAA diameter 59±9mm) were included. The median follow-up was 3 years (range 0-10 years). The survival rate was 92.8% (SE 1.5%), 76.5% (SE 3.1%) and 41.6% (SE 6%), at 2, 5 and 10 years of follow-up, respectively. In total, 78 patients died; 8 deaths (8/75, 10%) were aneurysm related. In multivariate regression analysis, age (CI. 1.02-1.14; p=0.006) and ever tobacco use (CI. 1.02-6.12, P=0.045) were associated with the long-term mortality. Freedom from re-intervention was 96% (SE 1.1%), 93% (SE 1.8%), 85.5% (SE 5%) at 2, 5 and 9 years of follow-up. Limb occlusion was a common complication (n/n; 30% of re-intervention), particularly within the first 2 postoperative years. Six patients presented with rupture and were treated with open conversion. EVAR cases with supra-renal fixation graft presented lower rates of ETIa (CI. 76-87.27, P<0.001).

CONCLUSIONS

Elective standard EVAR is associated with good long-term survival showing low aneurysm-related mortality. Common risk factors such as advanced age and smoking are associated to higher mortality. The procedure presents low re-intervention rates, while limb occlusion is a complication presented within the first 2 postoperative years.

Association of Neutrophil-Lymphocyte and Platelet-Lymphocyte Ratio with Adverse Events in Endovascular Repair for Abdominal Aortic Aneurysm

The association of chronic inflammatory markers with the clinical outcome after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) was investigated. We included 230 patients, treated electively with EVAR. The values of neutrophil–lymphocyte ratio (NLR) and platelet–lymphocyte ratio (PLR) were measured pre- and postoperatively. Any major adverse cardiovascular event (MACE) and acute kidney injury (AKI) were recorded. Adverse events occurred in 12 patients (5.2%). Seven patients suffered from MACE and five from AKI. Median NLR and PLR values were significantly increased after the procedure (NLR: from 3.34 to 8.64, p < 0.001 and PLR: from 11.37 to 17.21, p < 0.001). None of the patients or procedure characteristics were associated with the occurrence of either a MACE or AKI. Receiver operating characteristic curve analysis showed that postoperative NLR and PLR were strongly associated with AKI. A threshold postoperative NLR value of 9.9 was associated with the occurrence of AKI, with a sensitivity of 80% and specificity of 81%. A threshold postoperative PLR value of 22.8 was associated with the occurrence of AKI, with a sensitivity of 80% and specificity of 83%. Postoperative NLR and PLR have been associated with the occurrence of AKI after EVAR for AAA.

Early Outcomes of Carotid Revascularization in Retrospective Case Series

Background: Most data in carotid stenosis treatment arise from randomized control trials (RCTs) and cohort studies. The aim of this meta-analysis was to compare 30-day outcomes in real-world practice from centers providing both modalities. Methods: A data search of the English literature was conducted, using PubMed, EMBASE and CENTRAL databases, until December 2019, using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement (PRISMA) guidelines. Only studies reporting on 30-day outcomes from centers, where both techniques were performed, were eligible for this analysis. Results: In total, 15 articles were included (16,043 patients). Of the patients, 68.1% were asymptomatic. Carotid artery stenting (CAS) did not differ from carotid endarterectomy (CEA) in terms of stroke (odds ratio (OR) 0.98; 0.77–1.25; I² = 0%), myocardial ischemic events (OR 1.03; 0.72–1.48; I² = 0%) and all events (OR 1.0; 0.82–1.21; I² = 0%). Pooled stroke incidence in asymptomatic patients was 1% (95% CI: 0–2%) for CEA and 1% for CAS (95% CI: 0–2%). Pooled stroke rate in symptomatic patients was 3% (95% CI: 1–4%) for CEA and 3% (95% CI: 1–4%) for CAS. The two techniques did not differ in either outcome both in asymptomatic and symptomatic patients. Conclusion: Carotid revascularization, performed in centers providing both CAS and CEA, is safe and effective. Both techniques did not differ in terms of post-procedural neurological and cardiac events, both in asymptomatic and symptomatic patients. These findings reiterate the importance of a tailored therapeutic strategy and that “real-world” outcomes may only be valid from centers providing both treatments.

Management of Descending Thoracic Aortic Diseases: Similarities and Differences Among Cardiovascular Guidelines

Cardiovascular societies have developed recommendations regarding the management of thoracic aortic diseases. While improvements in treatment have been observed during the past decade in regard to patient selection, thoracic endovascular aortic repair (TEVAR) and associated techniques, and high-volume centralization, the broad expansion of TEVAR has raised considerations about its indications, appropriateness, limitations, and application. The aim of this systematic review was to assess the similarities and differences among current cardiovascular societies' guidelines for the management of thoracic aortic diseases. The MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were searched from January 2009 to May 2020. The initial search identified 990 articles. After exclusion of duplicate or inappropriate articles, the final analysis included 5 articles from cardiovascular societies published between 2010 and 2020. Selected controversial topics were analyzed, including diagnosis, imaging, spinal cord ischemia prevention, and management of the most important thoracic aortic pathologies. The analysis included data concerning the therapeutic approach in acute and chronic type B aortic dissection, penetrating aortic ulcer, intramural hematoma, thoracic aortic aneurysm, and traumatic aortic injury, as well a discussion of inflammatory aneurysms, aortitis, and genetic syndromes. The review presents consistent and controversial recommendations, as well as "gray zone" issues that need further investigation. There was significant overlap and agreement among the 5 societies regarding the management of thoracic aortic diseases. Especially in dissection and aneurysm management, TEVAR has established its role as the treatment of choice. However, robust evidence is still needed in many aspects of the management of thoracic aortic pathologies.

The TAXINOMISIS Project: A multidisciplinary approach for the development of a new risk stratification model for patients with asymptomatic carotid artery stenosis

INTRODUCTION

Asymptomatic carotid artery stenosis (ACAS) may cause future stroke and therefore patients with ACAS require best medical treatment. Patients at high risk for stroke may opt for additional revascularization (either surgery or stenting) but the future stroke risk should outweigh the risk for peri/post-operative stroke/death. Current risk stratification for patients with ACAS is largely based on outdated randomized-controlled trials that lack the integration of improved medical therapies and risk factor control. Furthermore, recent circulating and imaging biomarkers for stroke have never been included in a risk stratification model. The TAXINOMISIS Project aims to develop a new risk stratification model for cerebrovascular complications in patients with ACAS and this will be tested through a prospective observational multicentre clinical trial performed in six major European vascular surgery centres.

METHODS AND ANALYSIS

The risk stratification model will compromise clinical, circulating, plaque and imaging biomarkers. The prospective multicentre observational study will include 300 patients with 50%-99% ACAS. The primary endpoint is the three-year incidence of cerebrovascular complications. Biomarkers will be retrieved from plasma samples, brain MRI, carotid MRA and duplex ultrasound. The TAXINOMISIS Project will serve as a platform for the development of new computer tools that assess plaque progression based on radiology images and a lab-on-chip with genetic variants that could predict medication response in individual patients.

CONCLUSION

Results from the TAXINOMISIS study could potentially improve future risk stratification in patients with ACAS to assist personalized evidence-based treatment decision-making.

Multicenter Mid-term Results After Endovascular Aortic Aneurysm Repair with the Incraft® Device

OBJECTIVES

Durability after endovascular aortic aneurysm repair (EVAR) is considered an ongoing topic of investigation and was always a point of concern with smaller profile devices. Recently released five-year clinical trial results using the Incraft® ultralow profile device are encouraging. However, additional real-life experience will need to assist these initial findings. Herein, we investigated the outcomes after EVAR, in real world practice using the Incraft® endograft (EG).

MATERIAL AND METHODS

Seventy-seven patients with infrarenal abdominal aortic aneurysms (AAA) ≥50 mm in diameter treated with the Incraft® device in three vascular centers were enrolled from November 2015 to July 2018. Follow-up was completed in August 2020. Selection of EVAR using the Incraft® device was individualized according to aorto-iliac morphologic features, comorbidities, history of previous abdominal surgery and preference of the patient. At the early phase of the study, we specifically opted for preferential use of this low profile EG mainly in cases of small and tortuous iliac vessels (more challenging access routes). At later stages, it was used according to surgeon preference and not specifically in complex anatomies (real-world conditions). End-points included technical success, perioperative complications, 30-day survival, endoleg patency, presence of endoleaks, sac enlargement >5 mm and clinical success.

RESULTS

The primary technical success rate was 97.4% before the addition of an aortic cuff and iliac extension for a type Ia and type Ib endoleak respectively, and the repair of a maldeployment iliac component (primary-assisted and secondary technical success, 100%). Intraoperative small type II endoleaks (visible in final angiogram) were noted in 19 patients (24.7%). There were no intraoperative deaths from AAA rupture, primary conversions or conversions to aortounilateral grafts. Two complications occurred, necessitating hybrid techniques for repair (replaced of a dislodged endoleg and distal external iliac artery hemostasis). No deaths were reported within 30 days. Occlusion of an endoleg, was observed in two patients, 6 and 14 months respectively after implantation (2.6%), and were treated by femoral-femoral PTFE bypass after unsuccessful endovascular recanalization. The latter required open conversion, 3 mo later, to repair compromised flow to the inflow iliac axis. Three patients (3.9%) experienced sac enlargement >5 mm in diameter compared with the 1-month CT scan. All of these had type II endoleaks and two received embolization procedures. Eleven patients died from causes unrelated to AAA repair. Clinical success was 97.3%, 92.8% and 89.4% through 1, 2 and 3 years respectively.

CONCLUSIONS

EVAR with the Incraft® device might be considered a reliable option in real-world conditions and not specifically only in complex iliac anatomies.

Management of Abdominal Aortic Aneurysm Disease: Similarities and Differences Among Cardiovascular Guidelines and NICE Guidance

The development of endovascular techniques has improved abdominal aortic aneurysm (AAA) management over the past 2 decades. Different cardiovascular societies worldwide have recommended the endovascular approach as the standard of care in their currently available guidelines. While endovascular treatment has established its role in daily clinical practice, a new debate has arisen regarding the indications, appropriateness, limitations, and role of open surgery. To inform this debate, the MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases were searched from 2010 to May 2020; the systematic search identified 5 articles published between 2011 and 2020 by 4 cardiovascular societies and the National Institute of Health and Care Excellence (NICE). Four debatable domains were assessed and analyzed: diagnostic methods and screening, preoperative management, indications and treatment modalities, and postoperative follow-up and endoleak management. The review addresses controversial proposals as well as widely accepted recommendations and "gray zone" issues that need to be further investigated and analyzed, such as screening in women, medical management, and follow-up imaging. While the recommendations for AAA management have significant overlap and agreement among international cardiovascular societies, the NICE guidelines diverge regarding the role of open repair in aortic disease, recommending conventional surgery in most elective cases.

Frequency and predictors of chemotherapy-associated venous thromboembolism: the prospective PREVENT study

BACKGROUND

Our knowledge on the burden of symptomatic and asymptomatic venous thromboembolism (VTE) in patients with cancer undergoing chemotherapy is limited. The aim of our study was to prospectively investigate the frequency of symptomatic VTE and asymptomatic deep vein thrombosis of the lower limbs among cancer patients undergoing chemotherapy.

METHODS

We studied 231 patients (164 men) with pancreatic (N.=36), lung (N.=136), ovarian (N.=32) or prostate (N.=27) cancer receiving first line (N.=192, 83.1%) or adjuvant chemotherapy, followed-up for 3-6 months.

RESULTS

Some 17 patients were diagnosed with VTE, either asymptomatic detected on leg ultrasound (N.=7) or symptomatic (N.=10). The total frequency of VTE was 10.3% (17/165 with follow-up). Pancreatic cancer had the highest frequency of VTE (4/25, 16%) followed by ovarian (3/26, 11.5%) and lung cancer (10/94, 10.6%). There was no statistically significant difference in VTE rates among cancer types (P=0.36). VTE occurred more frequently in the presence of metastases (13/85, 15.3% vs. 4/80, 5.0%, for the remainder, P=0.03, OR 3.4). In the subgroup of patients receiving first line treatment, VTE occurred more frequently in patients with metastases (13/84, 15.5% vs. 2/53, 3.8%, for the remainder, P=0.033). In patients with pancreatic, lung or ovarian cancer receiving first line treatment, VTE occurred more frequently in patients with metastatic disease (19.1% vs. 4.0%, for the remainder, P=0.015).

CONCLUSIONS

VTE occurrence in this real-world patient cohort was high, reaching almost 20% in certain groups, like those with disseminated pancreatic, lung or ovarian cancer receiving first-line chemotherapy. Furthermore, VTE occurs mostly as a symptomatic event, being likely a result of the prothrombotic state of malignancy.

The effect of Endovascular Aneurysm Repair on Renal Function in Patients Treated for Abdominal Aortic Aneurysm

Aim:

The effect of endovascular aneurysm repair in patients treated for abdominal aortic aneurysm has not been clearly defined. The objective of the present article was to provide a contemporary literature review and perform an analysis to determine the effect of EVAR on renal function in the early post-operative period and during follow-up.

Methods:

A systematic review of the literature was undertaken to identify all studies reporting the effect of EVAR on renal function. Outcome data were pooled and combined overall effect sizes were calculated using fixed or random-effects models.

Results:

Thirty-two studies reporting on 24846 patients were included. Acute renal failure after EVAR occurred with an estimated frequency of 9% (95%CI: 5-16%; I2=97%). Median follow-up period was 19.5 months (range 1-60 months). The estimated frequency of chronic renal failure during follow-up was 7% (95%CI: 3-17%; I2=98%). Hemodialysis was required in 2% (1-3%; I2=97%) of the cases.

Conclusion:

High-level evidence demonstrating the effect of EVAR on the incidence of acute and chronic renal failure is lacking. Based on the current available data, nearly 10% of patients undergoing EVAR for AAA have an increased risk for renal dysfunction after the procedure. Whether this deterioration may lead to a worse outcome has not been adequately proved.

Anatomical Differences Between Intact and Ruptured Large Abdominal Aortic Aneurysms

Purpose: To compare different anatomical characteristics between intact and ruptured large abdominal aortic aneurysms (rAAA >80 mm) with the goal of refining the process of estimating rupture risk. Materials and Methods: A retrospective study involving 62 male patients with large (>80 mm) aneurysms matched for age and smoking produced a 31-patient elective group with a mean maximum aneurysm diameter of 92±9.7 mm and a 31-patient rAAA group (mean maximum aneurysm diameter 95.7±12 mm). Preoperative computed tomography angiography scans were analyzed with a dedicated workstation, and anatomical characteristics of the aortic neck, iliac arteries, and aneurysm were compared in multivariable regression analyses; the outcomes are given as the odds ratio (OR) with 95% confidence interval (CI). The prognostic utility of several characteristics as predictors of rupture occurrence was examined with receiver operating characteristic (ROC) curves. Results: Anatomical characteristics differing significantly between elective and ruptured aneurysms were the infrarenal aortic neck diameters at 5 mm, 10 mm and 15 mm; the neck length and calcification; the common iliac artery (CIA) lengths; the iliac artery indexes; the left CIA and external iliac artery diameters; and the total and true lumen aneurysm volumes. Intraluminal thrombus (ILT) volume did not differ (p=0.76), although its distribution in elective vs ruptured cases did [absent: 0% vs 19%, respectively (p=0.025); circumferential: 61% vs 35%, respectively (p=0.04)]. Total aneurysm volume was higher in rAAA (442±140 mL) vs intact AAA (331±143 mL, p=0.014), while the ILT/total aneurysm volume rate was lower in rAAA (55%) vs intact AAA (70%, p=0.02). Multivariate analysis determined that a shorter left CIA (OR 1.07, 95% CI 1.01 to 1.1, p=0.016) and a smaller total aneurysm volume (OR 1.007, CI. 1.001 to 1.014, p=0.016) were associated with intact AAA. After a ROC curve analysis, left CIA length <50 mm demonstrated a lower incidence of rupture (sensitivity 60% and specificity 78%), while total aneurysm volume <380 mL had 60% sensitivity and specificity. Conclusion: Large rAAAs seem to have different anatomical characteristics than similarly sized intact AAAs. Large intact AAAs have lower total aneurysm volumes and shorter left CIAs, with higher ILT/aneurysm volume rates.

Perioperative Management of DOACs in Vascular Surgery: A Practical Approach

BACKGROUND

Approximately 10-15% of patients on DOACs have to interrupt their anticoagulant before an invasive procedure every year. The perioperative management and monitoring of DOACs have proved to be challenging, as differences in patients' status and in the invasiveness of each procedure develop different situations that need a tailored therapeutic approach to each patient's needs.

METHODS

This review aims to summarize current evidence on the perioperative management of DOACs in patients undergoing a vascular surgical procedure focusing with a practical approach on three key clinical questions: (i) can we stop DOAC therapy before the vascular procedure? (ii) is bridging therapy necessary? and (iii) which is the best perioperative strategy for interruption and resumption of the anticoagulant therapy?

RESULTS

No specific data exist for the perioperative management of vascular surgery patients on DOACs, as most studies include low number of such patients. Therapeutic strategy on how to handle DOACs perioperatively must be based on their half-life, the bleeding risk of the invasive procedures, and on the thromboembolic risk of the patient. Renal function plays a crucial role in such situations, increasing thromboembolic and bleeding risk. In general, DOACs should be stopped 2 days for high bleed risk, 1 day for low risk and should be resumed 48-72 hrs after high risk, 24 hrs after low-risk procedure. Bridging is almost never needed.

CONCLUSION

Further perioperative research studies on patients undergoing vascular surgery are needed to confirm whether currently accepted therapeutic perioperative strategy is appropriate for these patients.

Endograft Specific Haemodynamics After Endovascular Aneurysm Repair: Flow Characteristics of Four Stent Graft Systems

OBJECTIVES

The implication of haemodynamics in the occurrence of complications after endovascular aneurysm repair (EVAR) has been raised in the literature. Different aortic stent graft configurations may lead to different haemodynamic properties. The current study deals with the post-operative haemodynamic variability between four stent graft systems with different structure, material, and type of fixation.

METHODS

Computed tomography data of 32 patients were used, equally distributed among the four endograft groups, namely the AFX, Endurant, Excluder, and Nellix. Velocity, wall shear stress (WSS), and helicity statistics were calculated, in regions around the flow division where disturbances are expected. The haemodynamic data were compared between and within the groups.

RESULTS

The morphology of AAAs pre-operatively did not vary significantly among the four groups. Before the flow division, lowest velocity was observed in Endurant cases and highest in Nellix cases. Endurant induced the lowest peak WSS and Nellix the highest (p = .03). The helicity levels were low in AFX and Nellix cases and high in Endurant and Excluder cases. After the flow division, the trend in the results was preserved. Nellix induced the highest velocity and WSS, followed closely by Excluder and AFX. There was a significant increase of helicity before and after flow division in AFX (p <0.001, R² = 0.09) and Nellix (p <0.001) cases.

CONCLUSIONS

It has been shown that different types of endografts induce variable haemodynamic conditions around the flow division. The parallel limb structure, featured by Nellix, seems to induce favourable flow conditions in terms of velocity and WSS, while helical flow before the flow division is suppressed. High WSS is generally considered to be a desirable flow characteristic in endovascular devices, whereas helicity extremes (very low or high) are potentially a negative sign. Endurant, with the stiffer material and the short neck structure, was associated with the lowest blood velocity and WSS values but preserved high helicity levels. The AFX and Excluder, which include the same material, induced similar haemodynamic conditions.

Suprarenal Aortic Remodeling after Endovascular Aortic Aneurysm Repair among Three Endografts with Different Types of Proximal Fixation System

BACKGROUND

Remodeling of suprarenal aorta after endovascular aortic aneurysm repair (EVAR) in relation to different endograft designs has not been thoroughly investigated. The aim of this study is to assess the anatomical configuration of the suprarenal aorta after using endografts with different proximal fixation during the first post-EVAR year.

METHODS

A retrospective study including EVAR patients using 3 types of endografts with different proximal fixation systems according to Instructions for Use was undertaken (50: Ovation, Endologix, Irvin, CA; 25: Endurant IIs, Medtronic, Santa Rosa, CA; 25: Excluder C3, W. L. Gore & Associates, Flagstaff, AZ). Comorbidities were recorded. Anatomic variables of the supra-aortic anatomy, abdominal aortic aneurysm (AAA) maximum diameter, and neck angulation were analyzed. Computed tomography angiography was obtained preoperatively at 1 and 12 months post-EVAR, while a duplex scan was undertaken at 6 months.

RESULTS

Comorbidities were not different across the 3 groups. Presence and amount of neck calcification (P = 0.139) and thrombus (P = 0.116) was similar among groups. Maximum aortic diameter showed significant reduction from preoperative measurements to 12-month postoperative ones, for all groups. (Ovation: 56.5 to 53 mm, P < 0.001; Endurant: 57 to 51 mm, P < 0.001; Excluder: 55 to 50 mm, P < 0.001). Suprarenal angulation was decreased significantly in the Ovation (P < 0.001) and Excluder groups (P = 0.05), while the infrarenal angulation was decreased in all groups. Among endografts, the decrease in AAA maximum diameter was similar (P = 0.99), while the suprarenal aortic diameter was significantly increased in Ovation patients in comparison to the other 2 endografts at the level of 5 mm (P = 0.02) and 25 mm (P = 0.01). Suprarenal angulation reduction was similar (P = 0.7), while infrarenal angulation was significantly more decreased in Ovation endograft than the other 2 systems (P < 0.001).

CONCLUSIONS

Proximal endograft configuration appears to have different impact on supra-aortic anatomy. Longer follow-up is needed to clarify future remodeling and clinical impact of these observations.

Large Diameter (≥29 mm) Proximal Aortic Necks Are Associated with Increased Complication Rates after Endovascular Repair for Abdominal Aortic Aneurysm

BACKGROUND

The aim of this study is to investigate the impact of proximal aortic diameter on outcome after endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysms (AAAs).

METHODS

This is a case-control (1:1) retrospective analysis of prospectively collected data on 732 AAA patients treated with EVAR in 2 university centers. Patients with an infrarenal neck diameter of 29-32 mm (wide neck, WN group) were compared with patients with a neck diameter of 26-28.9 mm (control group) matched for age, gender, and maximum aneurysmal sac diameter. Any patients treated outside the instructions for use of each endograft or with no adequate follow-up were excluded. The primary end point was any neck-related adverse event (a composite of type Ia endoleak, neck-related secondary intervention, and endograft migration) during follow-up.

RESULTS

Sixty-four patients with a proximal neck diameter of 29-32 mm (WN group) were compared with a matched control group of 64 patients with a neck diameter of 26-28.9 mm (control group). Oversizing was significantly higher in the study group (17.9% vs. 15.5%, P = 0.001). Overall median available follow-up was 24 months (range 12-84) (WN group 24 months vs. control group 18.5 months, P = 0.943). Primary end point was recorded in 8 patients (12.5%) of the WN group and in 1 patient (1.6%) of the control group. Freedom from the primary end point at 36 months (standard error <10%) was 87.3% for the study versus 98.4% for the control group (log rank = 4.66, P = 0.03). On multiple regression analysis, the presence of a proximal aortic neck >29 mm was the only independent risk factor for neck-related adverse events (odds ratio 7.4, 95% confidence interval 1.2-47.1).

CONCLUSIONS

EVAR in the presence of a wide proximal aortic neck is likely to be associated with higher adverse neck-related event rates and thus, in such cases closer follow-up may be required.

Haemodynamic performance of AFX and Nellix endografts: a computational fluid dynamics study

OBJECTIVES

The objective of this study is to analyse the flow conditions in the AFX and Nellix endografts (EGs) accounting for their postimplantation configuration in patients with an endovascular aneurysm repair-treated abdominal aortic aneurysm.

METHODS

We reconstructed post-endovascular aneurysm repair computed tomography scans of patients treated with an AFX or Nellix EG creating post-implantation EG models. We examined 16 patients, 8 in each group. The blood flow properties were obtained by computational fluid dynamics simulations and were subsequently compared with physiological infrarenal blood flow properties measured in 5 healthy subjects. Specifically, pressure drop, maximum velocity and wall shear stress were measured at peak systole and mean helicity at mid-diastole.

RESULTS

Our statistical analyses showed that the haemodynamic properties in both control regions did not vary statistically after the implantation of either the AFX or the Nellix EG, except for helicity that was significantly lower in the abdominal part of the Nellix EG compared with the expected physiological measurement. Regardless of the overall blood flow restoration, it is important to note that low pressure drop was detected along the limbs of the AFX and suppressed blood helical motion was detected at the entrance of the Nellix device.

CONCLUSIONS

It is observed from the results that the AFX EG has achieved absolute restoration of blood flow after endovascular aneurysm repair, although the development of secondary flow in the upper part of the EG and the low pressure drop in its limbs should be acknowledged. The Nellix EG also seems to be haemodynamically efficient. However, the suppression of helical flow before blood enters the device might raise concerns about its clinical application.

Endovascular aneurysm repair in patients with a wide proximal aortic neck: a systematic review and meta-analysis of comparative studies

INTRODUCTION

The aim was to investigate the impact of wide proximal aortic diameter on outcome after standard endovascular repair (sEVAR) of infrarenal abdominal aortic aneurysms.

EVIDENCE ACQUISITION

A systematic search of the literature was undertaken using the PUBMED, EMBASE, and Cochrane databases for articles comparing outcome after sEVAR in patients with large versus small diameter aortic neck. The prognostic factor of interest was large diameter proximal aortic neck and the results were reported as odds ratio (OR) or mean difference (MD) and 95% confidence interval (CI). A time-to-event data meta-analysis for late outcomes was performed using the inverse-variance method and reported the results as summary hazard ratio (HR) and 95% CI.

EVIDENCE SYNTHESIS

We identified 6 observational studies reporting on a total of 6602 patients (1616 with large and 4986 with small diameter neck). Patients with large proximal aortic neck were older (MD 0.87, 95% CI: 0.35-1.39; P=0.001). The prevalence of male gender (OR=1.63, 95% CI: 1.34-1.98; P<0.001), coronary artery disease (OR=1.20, 95% CI: 1.06-1.36; P=0.004), chronic obstructive pulmonary disease (OR=1.18, 95% CI: 1.03-1.36; P=0.02) and chronic kidney disease (OR=1.43, 95% CI: 1.23-1.66; P<0.001) was higher in the wide neck group. Patients with large diameter proximal neck had shorter proximal neck (MD=-1.91, 95% CI: -2.04 to -1.77; P<0.001) and a larger aneurysm diameter compared to those with small diameter neck (MD=3.40, 95% CI: 2.71-4.10; P<0.001). Patients with small diameter proximal neck had significantly higher freedom from aneurysm-related reintervention (HR=2.06, 95% CI: 1.23-3.45; P=0.006), freedom from type Ia endoleak (HR=6.69, 95% CI: 4.39-10.20; P<0.001), freedom from sac expansion (HR=10.07, 95% CI: 1.80-56.53; P=0.009), freedom from aneurysm rupture (HR 5.10, 95% CI: 1.40-18.58; P=0.01), and survival (HR=1.55, 95% CI: 1.08-2.24; P=0.02).

CONCLUSIONS

Patients with a wide proximal aortic neck undergoing standard EVAR were found to have worse outcome, as indicated by a lower freedom from aneurysm-related reintervention, type Ia endoleak, sac expansion and aneurysm rupture, and a higher overall survival. This anatomic characteristic should be considered in decision making. In such patients, closer imaging surveillance after EVAR in the long term may be required to identify early and treat timely the complications.

Abdominal aortic aneurysm endovascular repair: profiling post-implantation morphometry and hemodynamics with image-based computational fluid dynamics

Endovascular aneurysm repair (EVAR) has disseminated rapidly as an alternative to open surgical repair for the treatment of abdominal aortic aneurysms (AAAs), because of its reduced invasiveness, low mortality and morbidity rate. The effectiveness of the endovascular devices used in EVAR is always at question as postoperative adverse events can lead to re-intervention or to a possible fatal scenario for the circulatory system. Motivated by the assessment of the risks related to thrombus formation, here the impact of two different commercial endovascular grafts on local hemodynamics is explored through 20 image-based computational hemodynamic models of EVAR-treated patients (N=10 per each endograft model). Hemodynamic features, susceptible to promote thrombus formation, such as flow separation and recirculation, are quantitatively assessed and compared with the local hemodynamics established in image-based infrarenal abdominal aortic models of healthy subjects (N=10). The hemodynamic analysis is complemented by a geometrical characterization of the EVAR-induced reshaping of the infrarenal abdominal aortic vascular region. The findings of this study indicate that: (1) the clinically observed propensity to thrombus formation in devices used in EVAR strategies can be explained in terms of local hemodynamics by means of image-based computational hemodynamics approach; (2) reportedly pro-thrombotic hemodynamic structures are strongly correlated with the geometry of the aortoiliac tract postoperatively. In perspective, our study suggests that future clinical follow up studies could include a geometric analysis of the region of the implant, monitoring shape variations that can lead to hemodynamic disturbances of clinical significance.

Hostility of proximal aortic neck anatomy in relation to abdominal aortic aneurysm size and its impact on the outcome of endovascular repair with the new generation endografts

BACKGROUND

To assess the relation of abdominal aortic aneurysm (AAA) diameter with the proximal neck anatomy (PNA) hostility and to evaluate its impact on the endovascular aneurysm repair (EVAR) outcomes with the use of newer generation endografts.

METHODS

Retrospective analysis of single institution's recorded data from February 2009 to April 2016. Patients' characteristics, comorbidities, aortic morphology, perioperative characteristics and outcomes were analyzed. In relation to AAA diameter 2 groups were identified: group A (50-55 mm) and group B (>55 mm). Hostile PNA was defined based on: neck diameter >28 mm, length <15 mm, angulation >60o, and circumferential thrombus and/or calcification >50%. The aortic neck scoring system was calculated. Multiple logistic regression analysis with a forward likelihood ratio method adjusted for age and gender was undertaken.

RESULTS

Three hundred seventeen patients (96% males, mean age 72.4±9 years, 80% elective) were follow-up for a mean of 23.4 months (range, 3-86 months). No differences were observed in demographics and co-morbidities between the two groups (group A: 134, 42% vs. group B: 183, 58%). Hostile PNA was present in 147/317 (46%) patients and significantly more likely to be present in group B (P<0.001). In group B the aortic neck score was higher (P<0.001), the likelihood for having hostile PNA increased for neck diameter by 2.2-fold (OR 2.2, P=0.013, 95% CI: 1.18-4.03), length by 2.3-fold (OR 2.3, P=0.012, 95% CI: 1.20-4.51), angle by 4.8-fold (OR 4.8, P=0.002, 95% CI: 1.79-13.24) and presence of thrombus by 1.5-fold (OR 1.5, P=0.037, 95% CI: 1.45-10.34). No association existed for neck calcification (P=0.071). Technical success, adjunctive procedures, perioperative characteristics and outcomes were comparable in friendly and hostile PNAs.

CONCLUSIONS

PNA hostility is more likely in AAA with diameter >55 mm but with the use of newer generation endografts this did not influence the short- and mid-term EVAR outcomes. Longer follow-up is needed for a more definite conclusion.

Renal Function Impairment in Patients Undergoing Elective EVAR vs. Elective Open Repair During Follow up Period: A Systematic Review of the Literature

BACKGROUND

Endovascular (EVAR) or open surgical (OSR) repair are current treatment options for abdominal aortic aneurysm (AAA).

OBJECTIVE

To produce a systematic review comparing the impact of these 2 treatment options on renal function during mid- and long term follow up.

METHODS

The MEDLINE, EMBASE and Cochrane databases and key references were searched.

RESULTS

Six studies were included from 2000 to 2016, (4 retrospective and 2 RCT studies) reporting on 2,102 patients (54%; 1096 EVAR, 46%; 1006 OSR). The mean age in EVAR group ranged from 69.4 to 73.8 years (91% males), and in OSR group from 68 to 73.6 years (91% males). The data were too heterogeneous to perform a meta-analysis. All studies used GFR (Glomerular Filtration Rate) or estimated GFR (eGFR) to record renal function. The commonest risk factors were the presence of hypertension (77.5%), hyperlipidaemia (48.3%), coronary artery disease (42%) and smoking (37.8%). During follow up, new events of renal impairment (increase >20% in GFR) in EVAR patients and in OSR patients were 58 (5.3%) and 52 (5.2%), respectively. The mean GFR was decreased during follow up period in both types of the procedure.

CONCLUSION

There is lack of definitive evidence to prove the superiority of OSR over EVAR regarding renal function in the post-operative follow up period. It appears that renal impairment may occur after both interventions. Further prospective research is needed to clarify the issue.

Current status of endovascular treatment of aortoenteric fistula

Aortoenteric fistula (AEF) is one of the most challenging diagnostic and therapeutic entities in vascular surgery. AEF can occur either primarily involving the aorta and the gastrointestinal tract or, more commonly, secondary to previous aortic reconstructive surgery. Traditionally, the treatment of AEF includes graft excision and extra-anatomic bypass surgery or in situ graft replacement. However, recently endovascular repair has emerged as an alternative therapeutic option. In this article, we present published and current evidence for endovascular repair of primary and secondary AEF. When endovascular treatment is applied where appropriate, early outcomes seem to be superior compared to open surgery. This benefit may be lost during long-term follow-up, implying that a staged approach with early conversion to in situ grafting may realize the best patient survival and morbidity. Lifelong administration of antibiotics is associated with a reduction in re-infection. An endovascular approach used as a bridging procedure in unstable patients is recommended, followed by definitive open therapy, if feasible, in patients with good life expectancy.