Safety and Performance of a Cell-Impermeable Endoprosthesis for Hemodialysis Vascular Access Outflow Stenosis: A Brazilian Multicenter Retrospective Study.

PURPOSE: To evaluate the safety and performance of Wrapsody™, a cell-impermeable endoprosthesis (CIE), for treating hemodialysis vascular access outflow stenosis. MATERIALS AND METHODS: Investigators retrospectively analyzed 113 hemodialysis patients treated with a CIE (11/2021-12/2022) across four centers in Brazil. De novo or restenotic lesions were treated. The primary efficacy outcome measure was target lesion primary patency (TLPP) at 1, 3, 6, and 12 months; the primary safety outcome measure was the absence of serious local or systemic adverse events within the first 30 days post-procedure. Secondary outcome measures included technical and procedural success, access circuit primary patency (ACPP), and secondary patency at 1, 3, 6, and 12 months post-procedure. RESULTS: Thirty-nine patients (34.5%) had thrombosed access at the initial presentation, and 38 patients (33.6%) presented with recurrent stenosis. TLPP rates at 1, 3, 6, and 12 months were 100%, 96.4%, 86.4%, and 69.7%, respectively. ACPP rates were 100% at 1 month, 89.2% at 3 months, 70.9% at 6 months, and 56.0% at 12 months. The target lesion secondary patency rates at 1, 3, 6, and 12 months were 100%, 97.3%, 93.6%, and 91.7%, respectively. In the adjusted multivariate Cox regression analysis, male sex and endoprosthesis with diameters of 10, 12, 14, and 16 mm were associated with improved primary patency rates. No localized or systemic serious adverse event was observed through the first 30 days post-procedure. CONCLUSION: The CIE evaluated in this study is safe and effective for treating peripheral and central outflow stenoses in hemodialysis vascular access. LEVEL OF EVIDENCE: Level 2b, cohort study.

Endosutured Aneurysm Repair of Abdominal Aortic Aneurysms with Short Necks Achieves Acceptable Midterm Outcomes-Results from the Peru Registry.

BACKGROUND: The study aims to describe midterm outcomes following treatment of infrarenal abdominal aortic aneurysms (AAAs) with short necks by endosutured aneurysm repair using the Heli-FX EndoAnchor system. METHODS: This is a retrospective study of prospectively collected data from 9 vascular surgery departments between June 2010 and December 2019, including treated AAAs with neck lengths ≤10 mm. The decision for the use of EndoAnchors was made by the treating surgeon or multidisciplinary aortic committee according to each center's practice. There were 2 Groups further assessed according to neck length, A (≥4 and <7 mm) and B (≥7 and ≤10 mm). The main outcomes analyzed were technical success, freedom from type Ia endoleaks (TIaELs), sac size increase, all-cause and aneurysm-related mortality. RESULTS: Seventy-six patients were included in the study, 17 fell into Group A and 59 into Group B. Median follow-up for the cohort was 40.5 (interquartile range 12-61) months. A median of 6 (interquartile range 3) EndoAnchors were deployed in each subject. Technical success was 86.8% for the total group, 82.4% and 88.1% (P = 0.534) for Groups A and B respectively. Six out of 10 (60%) of TIaELs at the completion angiographies showed spontaneous resolution. Cumulative freedom from TIaEL at 3 and 5 years for the total group was 89% and 84% respectively; this was 93% and 74% for Group A and 88% at both intervals in Group B (P = 0.545). In total, there were 7 (9.2%) patients presenting with TIaELs over the entire study period. Two (11.8%) in Group A and 5 (8.5%) in Group B (P = 0.679). There were more patients with sac regression in Group B (Group A = 6-35.3% vs. Group B = 34-57.6%, P = 0.230) with no statistical significance. All-cause mortality was 19 (25%) patients, with no difference (4-23.5% vs. 15-25.4%, P = 0.874) between groups; whereas aneurysm-related mortality occurred in 1 patient from Group A and 3 from Group B. CONCLUSIONS: This study demonstrates reasonable outcomes for patients with short-necked AAAs treated by endosutured aneurysm repair in terms of TIaELs up to 5-year follow-up. EndoAnchor use should be judiciously evaluated in short necks and may be a reasonable option when anatomical constraints are encountered, mainly for those with 7-10 mm neck lengths. Shorter neck length aspects, as indicated by the results from Group A, may be an alternative when no other options are available or feasible.

Aortobifemoral bypass vs covered endovascular reconstruction of aortic bifurcation.

BACKGROUND: Covered endovascular reconstruction of aortic bifurcation (CERAB) is increasingly used as a first line-treatment in patients with aortoiliac occlusive disease (AIOD). We sought to compare the outcomes of patients who underwent CERAB compared with the gold standard of aortobifemoral bypass (ABF). METHODS: The Vascular Quality Initiative was queried for patients who underwent ABF or CERAB from 2009 to 2021. Propensity scores were generated using demographics, comorbidities, Rutherford class, and urgency. The two groups were matched using 5-to-1 nearest-neighbor match. Our primary outcomes were 1-year estimates of primary patency, major adverse limb events (MALEs), MALE-free survival, reintervention-free survival, and amputation-free survival. Standard statistical methods were used. RESULTS: A total of 3944 ABF and 281 CERAB cases were identified. Of all patients with AIOD, the proportion of CERAB increased from 0% to 17.9% between 2009 and 2021. Compared with ABF, patients who underwent CERAB were more likely to be older (64.7 vs 60.2; P < .001) and more often had diabetes (40.9% vs 24.1%; P < .001) and end-stage renal disease (1.1% vs 0.3%; P = .03). In the matched analysis (229 CERAB vs 929 ABF), ABF patients had improved MALE-free survival (93.2% [±0.9%] vs 83.2% [±3%]; P < .001) and lower rates of MALE (5.2% [±0.9%] vs 14.1% [±3%]; P < .001), with comparable primary patency rates (98.3% [±0.3%] vs 96.6% [±1%]; P = .6) and amputation-free survival (99.3% [±0.3%] vs 99.4% [±0.6%]; P = .9). Patients in the CERAB group had significantly lower reintervention-free survival (62.5% [±6%] vs 92.9% [±0.9%]; P < .001). Matched analysis also revealed shorter length of stay (1 vs 7 days; P < .001), as well as lower pulmonary (1.2% vs 6.6%; P = .01), renal (1.8% vs 10%; P < .001), and cardiac (1.8% vs 12.8%; P < .001) complications among CERAB patients. CONCLUSIONS: CERAB had lower perioperative morbidity compared with ABF with a similar primary patency 1-year estimates. However, patients who underwent CERAB experienced more major adverse limb events and reinterventions. Although CERAB is an effective treatment for patients with AIOD, further studies are needed to determine the long-term outcomes of CERAB compared with the established durability of ABF and further define the role of CEARB in the treatment of AIOD.

Stereolithographic (SLA) 3D Printing for Preprocedural Planning in Endovascular Aortic Repair of a Thoracic Aneurysm.

BACKGROUND: When treating aortic aneurysm patients with complex anatomical features, preprocedural planning aided by 3D-printed models offers valuable insights for endovascular intervention. This study highlights the use of stereolithographic (SLA) 3D printing to fabricate a phantom of a challenging aortic arch aneurysm with a complex neck anatomy. CLINICAL CASE: A 75-year-old female presented with a 58 mm descending thoracic aortic aneurysm (TAA) extending to the distal arch, involving the left subclavian artery (LSA) and the left common carotid artery (LCCA). The computed tomography (CT) scans underwent scrutiny by radiology and vascular teams. Nevertheless, the precise spatial relationships of the ostial origins proved to be challenging to ascertain. To address this, a patient-specific phantom of the aortic arch was fabricated utilizing an SLA printer and a biomedical resin. The thoracic endovascular aortic repair (TEVAR) procedure was simulated using fluoroscopy on the phantom to enhance procedural preparedness. Subsequently, the patient underwent a right carotid-left carotid bypass and a right carotid-left subclavian bypass. After a 24-hour interval, the patient underwent the TEVAR procedure, during which a 37 mm × 150 mm stent graft (CTAG, WL Gore and Associates, Flagstaff, AZ, USA) and a 40 mm × 200 mm stent graft (CTAG, WL Gore and Associates, Flagstaff, AZ, USA) were deployed, effectively covering the LSA and LCCA. Notably, the aneurysm exhibited complete sealing, with no indications of endoleaks or graft infoldings. At the 12-month follow-up, the patient remains in good health, with no evidence of endoleaks or any other surgery-related complication. CONCLUSION: This report showcases the successful use of a 3D-printed endovascular phantom in guiding the decision-making process during the preparation for a TEVAR procedure. The simulation played a pivotal role in selecting the appropriate stent graft, ensuring an intervention protocol optimized based on the patient-specific anatomy.

Multilayer Stent for Emergency Treatment of Acute Type B Aortic Dissection: A Case Report.

PURPOSE: We report the case of an acute type B dissection with high-risk features treated with multilayer stent. CASE REPORT: A 50-year-old female patient presented to the emergency department with an acute type B aortic dissection. Conservative medical treatment did control blood pressure but did not alleviate her dissection symptoms. She was treated endovascularly with multilayer stents extensively covering the whole dissected area. HThe aortic arch side branches, visceral arteries and renal arteries remained patent after treatment. The recovery was uneventful, and she was discharged the day after the intervention. At 6- and 12-month follow-up, the patient remained asymptomatic, the true lumen volume increased and all side branches remained patent. CONCLUSION: We present a case of the use of a multilayer stent for acute type B aortic dissection. This technique allows to treat the whole dissection with low risk of paraplegia or side branch occlusion. Long-term results of ongoing clinical studies should confirm the place of the multilayer stent as a treatment option for type B aortic dissection.

Aortoenteric fistulae and their multidisciplinary approach.

Aortoenteric fistula is an uncommun life-threatening condition which remains associated with significant morbidity and mortality. It can be primary (aneurysm, neoplasms, radiation therapy, infection) or secondary to vascular prosthesis. Early diagnosis and aggressive surgical treatment are very important to achieve optimal outcomes in these patients. The aim of this article is to highlight the importance of early diagnosis and multidisciplinary approach of aortoenteric fistula through the presentation of a clinical case.

La fístula aortoentérica es una patología poco frecuente, pero de riesgo vital, asociada a alta morbimortalidad. Puede ser primaria (aneurisma, neoplasia, radioterapia, infección) o secundaria a prótesis vascular. El diagnóstico precoz y el tratamiento quirúrgico agresivo son los pilares fundamentales para lograr buenos resultados en estos pacientes. El objetivo de este trabajo es destacar la importancia del diagnóstico precoz de la fístula aortoentérica y su manejo multidisciplinar, mediante la presentación de un caso clínico.

Braided stent-assisted coil embolization versus laser engraved stent-assisted coil embolization in patients with unruptured complex intracranial aneurysms.

PURPOSES: Braided and laser-cut stents both are efficacious and safe for coiling intracranial aneurysms. The study aimed to compare outcomes following braided stent-assisted coil embolization versus laser engraved stent-assisted coil embolization in 266 patients who were diagnosed with unruptured intracranial aneurysms of different types and locations. METHODS: Patients with unruptured complex intracranial aneurysms underwent braided (BSE cohort, n = 125) or laser engraved (LSE cohort, n = 141) stent-assisted embolization. RESULTS: The deployment success rate was higher for patients of the LSE cohort than those of the BSE cohort (140 [99%] vs. 117 [94%], p = 0.0142). Seventy-one (fifty-seven percentages) and 73 (52%) were coil embolization procedure success rates of the BSE and the LSE cohorts. Periprocedural intracranial hemorrhage was higher in patients of the BSE cohort than those of the LSE cohort (8 [6%] vs. 1 [1%], p = 0.0142). Four (three percentages) patients from the LSE cohort and 3 (2%) patients from the BSE cohort had in-stent thrombosis during embolization. Permanent morbidities were higher in patients of the LSE cohort than those of the BSE cohort (8 [6%] vs. 1 [1%], p = 0.0389). Higher successful procedures (76% vs. 68%) and fewer postprocedural intracranial hemorrhage (0% vs. 5%) and mortality (0% vs. 5%) were reported for patients of the BSE cohort in posterior circulation aneurysmal location than those of the LSE cohort. Laser engraved stent has fewer problems with deployment and may have better periprocedural and follow-up outcomes after embolization. CONCLUSIONS: Braided stent-assisted embolization should be preferred when the aneurysm is present in the posterior circulation.

Avant-Garde Endovascular Stent Graft Insertion in Dissected Ascending Thoracic Aortic Aneurysm.

Current guidelines and regulatory parameters for cardiothoracic surgery in the United States establish that open surgery is the first front line for treating ascending thoracic aortic aneurysms (ATAA). Despite advances in performing endovascular procedures in thoracic aortic aneurysms, there are no approved state-of-the-art techniques that allow endovascular procedures to be performed in ATAA. Thus, thoracic endovascular aortic repair (TEVAR) of the ascending aorta, as we will demonstrate, is a useful and effective technical opportunity for treating high-risk patients with type A dissections, intramural hematomas, and pseudoaneurysms. In this case, an 88-year-old female patient was consulted due to a preliminary diagnosed descending thoracic aortic aneurysm. As a result of uncertainty regarding the initial diagnosis, abdominal-pelvic and chest computed tomography scan tests contradicted the original conclusion and surprisingly yielded a different scenario; in fact, the patient had a dissected ATAA. Using the TEVAR procedure, the patient's ATAA was treated with a thoracic GORE TAG endograft stent (W. L. Gore & Associates, Inc., Newark, DE, USA). Four weeks later, the aneurysm was completely thrombosed, and the stent-graft was properly in place.

Totally Percutaneous Repair of an Aortic Arch Dissection: A Case Report.

Although the endovascular repair of descending thoracic aorta diseases is an already consolidated procedure, this approach is not well-established for ascending aorta and arch pathologies. A 71-year-old male patient who had undergone an open ascending aorta replacement ten years ago presented with a huge dissected aortic arch aneurysm. Vascular accesses were obtained with ultrasound-guided punctures, followed by aortic arch exclusion using aortic endoprostheses and the chimney-graft technique for preserving supra-aortic branches flow. This case demonstrates the feasibility of a totally percutaneous aortic arch repair provided that careful preprocedural planning and a dedicated team are available for such a challenging intervention.

Mid-Term Results of Left Carotid-Subclavian Bypass in Patients Undergoing Zone 2 TEVAR.

INTRODUCTION: The aim of this study was to present the mid-term results of patients who had undergone a carotid-subclavian bypass surgery after a thoracic endovascular aortic repair (TEVAR) stent-graft implantation with proximal landing at zone 2 of the aorta. METHODS: A total of 66 patients had undergone TEVAR and carotid-subclavian bypass between January 2015 and May 2020 at our clinic. Five of these patients were lost to follow-up, so 61 patients were included in this retrospective study. At follow-up visits, patency of the carotid-subclavian bypass grafts was evaluated with physical examination and radiological imaging. RESULTS: The mean follow-up time was 15.11±12.29 months (ranging from 1 to 56 months). There were 3 (4.91%) in-hospital deaths of patients admitted with bilateral lower limb and visceral malperfusion. There were also 2 (3.27%) deaths unrelated to the procedure. Carotid-subclavian graft occlusion occurred in 3 (4.91%) patients. The occlusion was detected with radiological imaging within a period of 12 to 24 months. The graft patency rate was 100% in the first 12 months. The mean graft patency time (survival) was 52.56±2.10 months. CONCLUSION: Periprocedural carotid-subclavian bypass surgery with synthetic grafts is a recommended procedure with high patency and acceptably low mortality and morbidity rates in TEVAR.

In vivo exclusion of giant aortic thrombus: Transesophageal echocardiography in thoracic endovascular aortic repair: A case report: Transesophageal echocardiography in thoracic endovascular aortic repair: A case report.

We present the case of a 53-year-old patient with a giant floating thrombus in the aortic arch associated with proximal stenosis of the left subclavian artery diagnosed by multimodal imaging. Left carotid-subclavian shunt and thoracic endovascular aortic repair (TEVAR) were successful. Transesophageal echocardiography (TEE) played a substantial role in the safety and efficacy of the endovascular procedure and should be considered as an additional guide to fluoroscopy for this type of procedure.

Laboratory "In-vitro" Evaluation of the Parallel Stent Graft Association for the Iliac Sandwich Technique.

OBJECTIVES: The Iliac Sandwich is an off-label technique that uses parallel stent grafts to treat aortoiliac aneurysms. The purpose of this experimental study is to evaluate the conformability and juxtaposition of stent grafts combinations used in this technique through in-vitro mechanical evaluation, computed tomography (CT) analyses, and a controlled pulsatile flow system. METHODS: The combinations of two Viabahn® ("V-V") or Viabahn® and Excluder® iliac extension ("V-E") were analysed using CT imaging with measurement of the gutter area by two independent analysts before and after balloon angioplasty. In a second phase, the parallel stent combinations were also evaluated using CT imaging after being implanted in the aortic aneurysm model with a pulsatile flow system with controlled temperature, viscosity, and density. RESULTS: The "V-E" group had a better conformability when compared to the "V-V" group, ensuring smaller gutter areas (0.0064 cm2 ± 0.01 vs. 0.0228 cm2 ± 0.03, p < 0.001). Post dilatation with two non-compliant balloons resulted in enlargement of the gutter area (Area A, p 0.065; Area B, p 0.071). Conversely, post dilatation with a non-compliant balloon for the internal iliac component and a compliant balloon for the external iliac device reduced the gutter area (Area A, p 0.008; Area B, p 0.010). CONCLUSION: The combination of Viabahn® and Excluder® iliac extension device ("V-E") had a smaller gutter area compared to two Viabahn® parallel stents for the Iliac Sandwich Technique. Post dilatation using a non-compliant balloon for the internal iliac device and a compliant balloon for the external iliac provided superior conformability and juxtaposition.

Tuberculous Aortic Aneurysm - A Review.

INTRODUCTION: Tuberculous aortic aneurysm (TBAA) is an exceedingly rare but severe manifestation of tuberculosis, with a high risk of sudden rupture of the aorta in absence of medical or surgical intervention. This review aimed to provide a detailed understanding of TBAA, including its associated complications, affected population, treatment measures, and outcomes. METHODS: Case studies and relevant research articles were analyzed to understand the recent advances in medical scientific knowledge on TBAA. Recent clinical case reports on TBAA were searched from the year 2010 to 2020. RESULTS: Case reports indicated a higher prevalence of TBAA in the male population. The most affected age group was 15 to 79 years. The most common treatment for TBAA included surgery followed by antituberculous medication. The case reports discussed in this review reflected open surgery, endovascular repair, coil embolization, laparotomy, aortic valve and root replacement as some of the surgical procedures used depending on the complication and type of aneurysm. The treatment outcome was considered effective in most cases. CONCLUSION: Postoperative chemotherapy and medications reduce the risk of severity. Early diagnosis of TBAA is imperative, followed by surgical resection and postoperative antituberculous medication with careful follow-up to prevent relapse.

Follow-up Results of Endovascular Aneurysm Repair Following Abdominal Visceral Debranching.

INTRODUCTION: The aim of this study is to present a series of six cases with thoracoabdominal aneurysm treated with hybrid technique in our center. METHODS: Between May 2015 and December 2018, the data of six patients with thoracoabdominal aneurysms and various comorbidities who underwent visceral debranching followed by endovascular aortic aneurysm repair were reviewed retrospectively. RESULTS: Patients' mean age was 65.3±19.6 years. All of them were male. Comorbidities were old age, congestive heart failure, coronary artery disease, chronic obstructive pulmonary disease, previous surgical interventions, and/or esophageal hemangioma. Except for one patient who underwent coronary artery bypass grafting (inflow was taken from ascending aorta), debranching was performed from the right iliac artery. Debranching of four visceral arteries (superior mesenteric artery, celiac trunk, and bilateral renal right arteries) was performed in three patients, of three visceral arteries (superior mesenteric artery, celiac trunk, right renal artery) was performed in one, and of two visceral arteries (superior mesenteric artery, celiac trunk) was performed in two patients. Great saphenous vein and 6-mm polytetrafluoroethylene grafts were used in one and five patients, respectively, for debranching. Endovascular aneurysm repair was performed following debranching procedures as soon as the patients were stabilized. In total, three patients died at the early, mid, and long-term follow-up due to multiorgan failure, pneumonia, and unknown reasons. CONCLUSION: Hybrid repair of thoracoabdominal aneurysms may be an alternative to fenestrated or branched endovascular stent grafts in patients with increased risk factors for open surgical thoracoabdominal aneurysm repair; however, the procedure requires experience and care.

Extracellular matrix-derived and low-cost proteins to improve polyurethane-based scaffolds for vascular grafts.

Vascular graft surgeries are often conducted in trauma cases, which has increased the demand for scaffolds with good biocompatibility profiles. Biodegradable scaffolds resembling the extracellular matrix (ECM) of blood vessels are promising vascular graft materials. In the present study, polyurethane (PU) was blended with ECM proteins collagen and elastin (Col-El) and gelatin (Gel) to produce fibrous scaffolds by using the rotary jet spinning (RJS) technique, and their effects on in vitro properties were evaluated. Morphological and structural characterization of the scaffolds was performed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Micrometric fibers with nanometric rugosity were obtained. Col-El and Gel reduced the mechanical strength and increased the hydrophilicity and degradation rates of PU. No platelet adhesion or activation was observed. The addition of proteins to the PU blend increased the viability, adhesion, and proliferation of human umbilical vein endothelial cells (HUVECs). Therefore, PU-Col-El and PU-Gel scaffolds are promising biomaterials for vascular graft applications.

Endovascular repair of abdominal and thoracoabdominal aneurysms using chimneys and periscopes is associated with poor outcomes.

OBJECTIVE: Chimneys and periscopes are often used to treat pararenal or thoracoabdominal aneurysms de novo or after failed open or endovascular repair. We sought to describe our institutional experience, given their limited success and questionable long-term outcomes. METHODS: We retrospectively reviewed the electronic records for patients treated with chimneys/periscopes from 1997 through 2020. Baseline characteristics, procedural details, periprocedural complications, reinterventions, and midterm outcomes were collected. RESULTS: Fifty-eight patients (86 vessels) were treated; the median follow-up was 32 months (range, 0.03-104 months). There were 36% (n = 21) juxta-renal, 2% (n = 1) para-visceral, and 21% (n = 12) thoracoabdominal aneurysms, and 41% (n = 24) had pararenal failure of prior endovascular aneurysm repair (n = 17) or open repair (n = 7). Stent configuration for the majority of the 86 vessels (n = 80; 93%) treated were chimney configuration (n = 6 periscopes; 7%). The most common stent graft utilized was Viabahn, and 8.1% (n = 7) were reinforced with a bare metal stent. Although the majority of the cases were elective, 36.2% (n = 21) of the cases were urgent/emergent. At the conclusion of the initial procedure, 16 of 58 patients had an endoleak (gutter, 50% [8/16]; type Ia, 25% [4/16]; and type II, 25% [4/16]). On follow-up, 14 of 58 patients developed one or more endoleaks, with the most common endoleaks being a gutter endoleak (35% [7/20]). Other endoleaks observed included 30% (6/20) type III, 15% (3/20) type Ia, 15% (3/20) type Ib, and 5% (1/20) type II. Eleven of 58 patients underwent interventions for one or more endoleak (gutter, 33% [5/15]; type Ib, 20% [3/15]; type II, 7% [1/15]; and type III, 40% [6/15]). Twelve of 58 patients returned to the operating room for one or more procedures during the index hospitalization (five laparotomies, three dialysis access, three acute limb ischemia, and four chimney/periscope interventions). Ten of 58 patients underwent angioplasty/stenting for chimney/periscope compression or occlusion during the follow-up period. Survival was 61.3% at 1 year by Kaplan-Meier analysis (75% for elective, 37% for urgent/emergent) (aneurysm-related death, 22%). Cox hazard modeling showed that aneurysm diameter (hazard ratio, 1.03; 95% confidence interval, 1.004-1.05; P = .02) and urgent/emergent interventions (hazard ratio, 3.6; 95% confidence interval, 1.33-9.74; P = .01) were predictors of mortality. CONCLUSIONS: Endovascular repair of aortic aneurysms with chimneys/periscopes is associated with poor outcomes, including limited technical success and aneurysm exclusion, as well as high morbidity and mortality, with a high rate of reinterventions both in the immediate postoperative period and on follow-up. They should be used only when other surgical or endovascular options are not possible.

Failure Analysis of TEVG's II: Late Failure and Entering the Regeneration Pathway.

Tissue-engineered vascular grafts (TEVGs) are a promising alternative to treat vascular disease under complex hemodynamic conditions. However, despite efforts from the tissue engineering and regenerative medicine fields, the interactions between the material and the biological and hemodynamic environment are still to be understood, and optimization of the rational design of vascular grafts is an open challenge. This is of special importance as TEVGs not only have to overcome the surgical requirements upon implantation, they also need to withhold the inflammatory response and sustain remodeling of the tissue. This work aims to analyze and evaluate the bio-molecular interactions and hemodynamic phenomena between blood components, cells and materials that have been reported to be related to the failure of the TEVGs during the regeneration process once the initial stages of preimplantation have been resolved, in order to tailor and refine the needed criteria for the optimal design of TEVGs.

Computational Characterization of Mechanical, Hemodynamic, and Surface Interaction Conditions: Role of Protein Adsorption on the Regenerative Response of TEVGs.

Currently available small diameter vascular grafts (<6 mm) present several long-term limitations, which has prevented their full clinical implementation. Computational modeling and simulation emerge as tools to study and optimize the rational design of small diameter tissue engineered vascular grafts (TEVG). This study aims to model the correlation between mechanical-hemodynamic-biochemical variables on protein adsorption over TEVG and their regenerative potential. To understand mechanical-hemodynamic variables, two-way Fluid-Structure Interaction (FSI) computational models of novel TEVGs were developed in ANSYS Fluent 2019R3® and ANSYS Transient Structural® software. Experimental pulsatile pressure was included as an UDF into the models. TEVG mechanical properties were obtained from tensile strength tests, under the ISO7198:2016, for novel TEVGs. Subsequently, a kinetic model, linked to previously obtained velocity profiles, of the protein-surface interaction between albumin and fibrinogen, and the intima layer of the TEVGs, was implemented in COMSOL Multiphysics 5.3®. TEVG wall properties appear critical to understand flow and protein adsorption under hemodynamic stimuli. In addition, the kinetic model under flow conditions revealed that size and concentration are the main parameters to trigger protein adsorption on TEVGs. The computational models provide a robust platform to study multiparametrically the performance of TEVGs in terms of protein adsorption and their regenerative potential.

The revascularization of the left subclavian artery with a cross over axilloaxillary bypass for the hybrid repair of thoracic aortic aneurysms.

AIM: We present our subclavian artery revascularization experiences in the patients with thoracic aortic aneurysm who underwent hybrid repair. MATERAIL AND METHODS: Between May 2015-December 2018,4 patients underwent TEVAR procedure following axilloaxillary bypass grafting.The mean age of the patients was 72.5 ± 3.01 years.One patient was female and 3 patients were male.Patients had thoracic aortic aneurysms including the left subclavian artery or aberrant right subclavian artery. RESULTS: All patients underwent endovascular stent graft repair following axilloaxillary bypass grafting in the same day.Mortality did not occur in the perioperative period.One patient had graft infection at 8th month of the operation and the graft was removed.He was lost due to pneumonia following the operation.The control computed tomographies of the other 3 patients revealed patent grafts together with successful endovascular interventions and they have been following uneventfully a mean of 27±6.2 months (range:24-32,median:29). CONCLUSION: The risk of stroke,spinal cord ischemia, and upper extremity ischemia are found higher in the patients who underwent coverage of the left subclavian artery without revascularization.The axilloaxillary bypass grafting may be performed in the patients with high risk to prevent carotid artery manipulation and clamping during carotid-subclavian bypass with long term promising patency rates.

OBJETIVO: Presentamos nuestras experiencias de revascularización de la arteria subclavia en los pacientes con aneurisma de aorta torácica sometidos a reparación híbrida. MATERIAL Y MÉTODOS: entre mayo de 2015 y diciembre de 2018, 4 pacientes fueron sometidos a TEVAR después de un injerto de derivación axiloaxilar. La edad media de los pacientes fue 72,5 ± 3,01 años. Un paciente era mujer y 3 pacientes eran varones. Los pacientes tenían aneurismas de la aorta torácica incluyendo el arteria subclavia izquierda o arteria subclavia derecha aberrante. RESULTADOS: Todos los pacientes fueron sometidos a reparación endovascular con endoprótesis vascular en el mismo día después de un bypass axiloaxilar, no hubo mortalidad en el perioperatorio, un paciente presentó infección del injerto a los 8 meses de la operación y se retiró el injerto, se perdió por neumonía Las tomografías computarizadas de control de los otros 3 pacientes revelaron injertos permeables junto con intervenciones endovasculares exitosas y han estado siguiendo sin incidentes una media de 27 ± 6,2 meses (rango: 24-32, mediana: 29). CONCLUSIÓN: El riesgo de ictus, isquemia medular e isquemia de la extremidad superior es mayor en los pacientes sometidos a cobertura de la arteria subclavia izquierda sin revascularización; en los pacientes con alto riesgo se puede realizar un bypass axiloaxilar para prevenir la manipulación de la arteria carótida. y pinzamiento durante la derivación carótido-subclavia con tasas de permeabilidad prometedoras a largo plazo.

Multi-Branched Thoracoabdominal Endovascular Aortic Repair With Branch Access Through a Left Thoracotomy and Descending Thoracic Aortic Conduit: A Novel and Effective Alternative Access.

PURPOSE: To demonstrate an alternative access to perform directional branch catheterization during complex endovascular aortic repair. TECHNIQUE: Urgent endovascular aortic repair was indicated to treat a symptomatic post dissection thoracoabdominal aneurysm with large infrarenal dilatation with an off-the-shelf t-Branch endograft (Cook Medical, Bloomington, IN, USA). Traditional proximal arterial accesses were not suitable due to a previous aortic arch endograft. A novel approach was performed through a left postero-lateral thoracotomy, isolation of the descending thoracic aorta and anastomosed a polyester graft conduit to allow sheaths passage to the thoracoabdominal aorta with subsequently directional branch catheterization. CONCLUSION: The descending thoracic aortic conduit technique is an effective alternative for directional branch catheterization and should be considered whenever traditional proximal arterial accesses are not suitable and other endografts configurations not considered due to anatomic limitations.