Three-Dimensional (3D) Microcatheter Shaping Using Touch Screen Devices for Cerebral Aneurysm Coil Embolization

OBJECTIVE

In cerebral aneurysm coil embolization, proper microcatheter shaping is crucial to reduce complications and achieve sufficient embolization. Shaping a microcatheter in 3 dimensions (3D) is often required but can be challenging. We assessed the usefulness of a novel shaping on screen (SOS) method that displays real-size 3D rotational angiography (RA) images on a touch screen device during cerebral aneurysm embolization to facilitate 3D microcatheter shaping.

METHODS

In this study, 18 patients with cerebral aneurysm treated with this technique were included. Real-size 3D-RA images obtained during the embolization procedure were displayed on the touch screen device, which allowed for real-time manipulation. The shape of the microcatheter was adjusted to conform to the curvature of the vessel by swiping the touch screen device and bending the mandrel accordingly. We assessed the clinical and angiographic results, along with the accuracy and stability of the microcatheter.

RESULTS

No procedure-related complications were observed. The mean packing density was 41% ± 12%. In all but 1 case, microcatheters were inserted into the aneurysms without guidewire assistance. After coiling, all microcatheter forms were stable.

CONCLUSIONS

Three-dimensional (3D) microcatheter shaping using touch screen devices during cerebral aneurysm coil embolization may be simple and safe and can achieve high packing density of aneurysms.

Aortic Arch Debranching and Thoracic Endovascular Aortic Repair (TEVAR) for Type B Aortic Dissection

BACKGROUND

Since its introduction, thoracic endovascular aortic repair (TEVAR) has revolutionized the treatment of type B aortic dissections (TBADs). However, the proximal aspect of the aortic pathology treated may infringe on the origin of the left subclavian artery or even more proximally. Hence, to ensure durable outcomes, the origin of these vessels needs to be covered, but an extra-anatomical bypass is required to perfuse vital branches, known as aortic arch debranching. This series aims to describe and delineate the disparities of aortic arch debranching during TEVAR for TBAD.

METHODS

A retrospective review and analysis of a multicenter international database was conducted to identify patients with TBAD treated with TEVAR between 2005 and 2021. Data analyzed included patient demographics, disease characteristics, operative characteristics, and postoperative outcomes with follow-up on mortality and reintervention. All statistical analyses were carried out using IBM SPSS 26. Patient survival was calculated using a Kaplan-Meier survival analysis, and a P value of less than 0.05 was considered statistically significant.

RESULTS

A total of 58 patients were included in the analysis, of which 27 (46.6%) presented with complicated disease and 31 were uncomplicated, of which 10 (17.2%) were classed as high risk and 21 (36.2%) low risk. Zone 2 was the most common proximal landing zone for the stent graft. Left subclavian artery bypass was performed selectively (26%), with 1 stroke occurring, likely due to embolic reasons. A further 6 underwent more proximal aortic debranching before TEVAR (10%) and was a significant risk factor for mortality and the number of stents deployed. The overall rates of reintervention and mortality were 17.2% (n = 10) and 29.3% (n = 17).

CONCLUSIONS

Aortic arch debranching and TEVAR for TBAD is associated with significant mortality. Future developments to treat aortic arch pathology could incorporate branched graft devices, eliminating the need for debranching, improving stroke rates, and reducing future reinterventions.

Outcomes of Zone 1 Thoracic Endovascular Aortic Repair With Fenestrated Surgeon-Modified Stent-Graft for Aortic Arch Pathologies

OBJECTIVES

This study evaluated the feasibility and safety of zone 1 thoracic endovascular aortic repair (TEVAR) with fenestrated surgeon-modified stent-graft (SMSG) for aortic arch pathologies.

METHODS

Between March 2016 and November 2020, 34 consecutive patients underwent zone 1 TEVAR with fenestrated SMSG for aortic arch pathologies. Outcomes included technical success, perioperative, and follow-up morbidity and mortality.

RESULTS

During the study period, 34 patients were treated with zone 1 TEVAR with fenestrated SMSG. Twenty-four (70.6%) patients presented with type B aortic dissections, 9 (26.5%) patients presented with aneurysms (7 located on the lesser curvature side of aortic arch), 1 (2.9%) patient presented with type Ia endoleak after previous TEVAR owing to traumatic aortic dissection. The proximal landing zone for all patients were in zone 1, and all supra-aortic trunks were reconstructed, except for one left subclavian artery. Technical success was achieved in all cases. The 30-day estimated survival (±SE) was 90.9% ± 5.0% [95% confidence interval (CI): 77.0%-97.0%]. The 30-day estimated freedom from reintervention (±SE) was 87.9% ± 5.7% (95% CI: 73.4%-95.3%). At a median follow-up of 48 months (range, 12-68 months), 2 patients died, including 1 aortic-related death and 1 non-aortic-related death. One patient had reintervention 13 months after the operation owing to type Ia endoleak. All supra-aortic trunks were patent. The estimated survival (±SE) during follow-up was 85.1% ± 6.2% (95% CI: 69.9%-93.6%). One (2.7%) patient had stroke. The estimated freedom from reintervention (±SE) during follow-up was 84.2% ± 6.5% (95% CI: 69.9%-93.5%).

CONCLUSIONS

Zone 1 TEVAR with fenestrated SMSG is an alternate option for treatment of aortic arch pathologies in experienced centers.

Endovascular repair combined with in situ fenestration for new-onset or residual arch dissection in patients underwent aortic replacement

INTRODUCTION

Ascending aorta or hemi-arch replacement is a frequently used treatment for patients with acute type A thoracic aortic dissection, particularly those who are elderly or have multiple comorbidities. However, in cases where there are secondary entry tears in the aortic arch or descending aorta, this procedure may not fully resolve the issue. The true lumen may remain compressed due to perfusion of the false lumen and usually require reoperation.

METHODS

Between January 2019 and July 2022, 18 patients underwent endovascular total aortic arch repair and fenestration technique without requiring median re-sternotomy. Aortic stent grafts were implanted via the femoral approach, utilizing prosthetic vessels as an appropriate proximal landing zone for aortic stent graft deployment. Based on the debranching conditions of the arch in previous surgery, single, double or triple in situ fenestrations (ISFs) were performed, respectively.

RESULTS

All 18 cases were technically successful, with a median follow-up period of 20 months (range: 18-31 months). All patients had a favourable postoperative course, with no deaths within 30 days or during their hospital stay. There were no instances of disabling stroke, paraplegia, endo-leak, stent graft migration or stent graft-induced new entry. In addition, all patients exhibited complete thrombosis of the false lumen at the level of the aortic arch.

CONCLUSION

Our preliminary experience suggests that endovascular total arch repair combined with ISF technique is a viable, effective and safe option for treatment. Our mid-term results have been promising, but we acknowledge the need for further evaluation to assess long-term outcomes and durability.

Towards biomechanics-based pre-procedural planning for thoracic endovascular aortic repair of aortic dissection

BACKGROUND AND OBJECTIVE

Although thoracic aortic endovascular repair (TEVAR) has shown promising outcomes in the treatment of patients with complicated type B aortic dissection, complications still occur after TEVAR that can lead to catastrophic events. Biomechanical interactions between the stent-graft (SG) and the local aortic tissue play a critical role in determining the outcome of TEVAR. Different SG design may cause different biomechanical responses in the treated aorta, but such information is not known at the time of pre-procedural planning. By developing patient-specific virtual stent-graft deployment tools, it is possible to analyse and compare the biomechanical impact of different SGs on the local aorta for individual patients.

METHODS

A finite element based virtual SG deployment model was employed in this study. Computational simulations were performed on a patient-specific model of type B aortic dissection, accounting for details of the SG design and the hyperelastic behaviour of the aortic wall. Based on the geometry reconstructed from the pre-TEVAR CTA scan, the patient-specific aortic dissection model was created and pre-stressed. Parametric models of three different SG products (SG1, SG2 and SG3) were built with two different lengths for each design. The SG models incorporated different stent and graft materials, stent strut patterns, and assembly approaches. Using our validated SG deployment simulation framework, virtual trials were performed on the patient-specific aortic dissection model using different SG products and varying SG lengths.

CONCLUSION

Simulation results for different SG products suggest that SG3 with a longer length (SG3-long) would be the most appropriate device for the individual patient. Compared to SG1-short (the SG deployed in the patient), SG3-long followed the true lumen tortuosity closely, resulted in a more uniform true lumen expansion and a significant reduction in peak stress in the distal landing zone. These simulation results are promising and demonstrate the feasibility of using the virtual SG deployment model to assist clinicians in pre-procedural planning.

Novel conformable stent-graft repair of abdominal aortic aneurysms with hostile neck anatomy: A single-centre experience

OBJECTIVES

Abdominal aortic aneurysms (AAAs) demonstrating hostile neck anatomy (HNA) are associated with increased perioperative risk and mortality. A number of these patients are not suitable for standard endovascular aneurysm repair (EVAR) and are high risk for open surgery. We present our experience with the first implantations in Scotland of a novel conformable aortic stent-graft designed to overcome some of the challenges of HNAs.

METHODS

From May 2018 to March 2022, 24 consecutive patients with non-ruptured AAAs demonstrating HNAs (neck length < 15 mm, or angulation > 60°) were treated with GORE Excluder Conformable AAA endoprosthesis (CLEVAR) (CEXC Device, W.L. Gore and Associates, Flagstaff, AZ, USA) at a Scottish vascular centre. We assessed clinical outcomes and technical success of CLEVAR during deployment, primary admission and the post-operative period at 3- and 12-month clinical follow-up alongside CT angiography.

RESULTS

Twenty-four patients (20 males, mean age 75.6) were included. Primary technical success of proximal seal zones and CLEVAR deployment (no type 1/3 endoleaks, no conversion to open repair, AAA excluded and patient leaving theatre alive) was achieved in 100% of patients. All patients were alive and clinically stable at 3- and 12-month follow-up. There were five patients requiring re-intervention; at the 3-month follow-up, one patient (4.2%) developed a type 1b endoleak requiring graft limb extension, one patient developed a right common femoral artery dissection requiring open repair and one patient required a limb extension of the right iliac limb due to risk of developing a type 1b endoleak. At the 12-month follow-up, two patients required embolization of type 2 endoleaks and no patients demonstrated type 1 or type 3 endoleaks.Conclusions: In-hospital and post-operative 3- and 12-month clinical and angiographic outcomes demonstrate safety and efficacy with CLEVARs in treating unruptured AAAs with HNA. Further research involving larger heterogenous sample sizes is warranted to determine long-term clinical outcomes.

Systematic review of the results of fenestrated endovascular aortic repair in octogenarians

INTRODUCTION

With the increasing life expectancy of Western populations, more octogenarians are presenting with large abdominal aortic aneurysm (AAA). Endovascular repair offers a less invasive alternative and older patients who may not have been offered open repair in the past are now being considered for elective repair with this approach. Age in isolation may not be the only consideration in recommending elective aneurysm repair. We aimed to review the literature on complex endovascular AAA repairs (mainly fenestrated endovascular aortic repair [FEVAR]) in octogenarians.

METHODS

A literature search was conducted using the Ovid Medline®, Embase® and Cochrane Library databases for articles published up to January 2022. All English language publications from 1995 onwards were eligible for inclusion. Search terms included: "FEVAR", "F-EVAR", "fenestrated EVAR", "fenestrated endovascular aortic repair", "fenestrated endovascular aneurysm repair", "fenestrated AAA repair", "fenestrated endograft", "fenestrated stent graft", "fenestrated", "endograft", "EVAR", "octogenarian", "elderly", "above 80" and "over 80".

METHODS

The literature search identified 134 potential articles. Following qualitative assessment by two independent appraisers, this was refined to 11 studies, in accordance with the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) statement.

RESULTS

The primary outcome measure was 30-day mortality, which was highly variable, ranging from 0% to 9% in octogenarians and from 0% to 5% in non-octogenarians. However, these differences were only found to be statistically significant in two studies. The secondary outcome measures included technical success rates, major adverse events, reintervention rates, freedom from reintervention, target vessel patency, freedom from target branch instability, and length of hospital and intensive care unit stay. No statistically significant differences were found between octogenarians and non-octogenarians. Long-term survival was significantly lower for octogenarians in two studies.

CONCLUSIONS

The perioperative outcomes of FEVAR in octogenarians are comparable with those of younger patients. FEVAR therefore appears to be an acceptable option for complex endovascular aneurysm repairs in carefully selected octogenarians. Nevertheless, this review highlights the paucity of published data on the outcomes of endovascular repair of complex aneurysms in octogenarians.

Thoracic Endovascular Repair after Total Aortic Arch Replacement with Frozen Elephant Trunk for Type a Aortic Dissection

BACKGROUND

The management of residual aortic dissection after initial type A repair with the Frozen elephant trunk technique remains mostly unexplored. This work aimed to evaluate endovascular second-stage surgery for patients with residual aortic dissection.

METHODS

A retrospective analysis of consecutive patients that underwent Type A aortic repair with Frozen elephant trunk, followed by a second-stage endovascular procedure was done from March 2016 to December 2021. The primary outcome was aortic-related adverse events or mortality, and secondary outcomes were aortic remodeling and perioperative complications. Remodeling was assessed by comparing the difference in ratios for true lumen/total aortic diameters on pre-operative and follow-up scans.

RESULTS

Thirty-four patients underwent second-stage surgery after Type A repair during the study period (7 thoracic endovascular aortic repair extensions, 1 STABLE/PETTICOAT, and 26 STABILISE). Median follow-up was 23 months (range 2-66 months). There were no perioperative deaths or major complications and 1 reoperation for left subclavian re-embolization. At the last follow-up, there was no aortic-related mortality. There were 5 aortic-related adverse events, including another subclavian re-embolization and a preplanned open conversion. Risk factors were connective tissue disorders (P = 0.01) and aortic aneurysms >55 mm (P = 0.03). Distal remodeling reached statistical significance in all segments (P < 0.01) and was greater for patients treated with the STABILISE technique when compared to extended thoracic endovascular aortic repair (P = 0.01).

CONCLUSIONS

Second-stage endovascular management of residual aortic dissection after initial Frozen elephant trunk repair showed excellent perioperative and good midterm outcomes and induced significant remodeling of the entire aorta in most cases, particularly with the STABILISE procedure.

Anatomical suitability for branched endovascular aortic arch repair and balloon-expandable bridging stent grafts in a cohort of patients previously treated with a hybrid approach

OBJECTIVE

We assessed the suitability of two triple branch arch devices (aBranch) (Terumo aortic and Cook Medical) and a balloon-expandable covered stent (VBX, W. L. Gore & Associates, Johnson & Johnson) to incorporate the brachiocephalic trunk (BCT) in a cohort previously treated with hybrid thoracic endovascular repair (TEVAR).

METHODS

This is a single-center, retrospective, all-comers, preclinical suitability study. We conducted an analysis of preoperative computed tomography scans in surgical patients between 1999 and 2022 in a single vascular surgery unit. The primary outcome was the aortic suitability of aBranch devices and VBX as mating stent for BCT in previous hybrid TEVAR. Hybrid repair of the aortic arch included TEVAR, fenestrated or branched TEVAR associated with any surgical debranching of the supra-aortic trunks and chimney TEVAR with proximal landing in zones 0 to 2. Secondary outcomes included (i) suitability assessment when excluding minor instruction for use (IFU) criteria, (ii) a comparison of suitable and nonsuitable patients, (iii) risk factors analysis for nonsuitability, and (iv) a description of the exclusion causes.

RESULTS

During the study period, 120 patients were treated. Among elective patients (n = 73), the suitability of any aBranch was 82.2% (60/73) and VBX was suitable in 64.4% of BCTs (47/73). The aBranch suitable patients had a significantly longer sinotubular-BCT length (P = .017) and smaller distal ascending aorta (P = .043) as compared with nonsuitable ones. The suitability of Terumo Aortic and Cook Medical devices was 52.1% (38/73) and 46.6% (34/73), respectively. When minor IFU criteria were ignored, suitability increased to 82.2% (60/73) and 63.0% (46/73), respectively. Left common carotid artery diameter and sinotubular-BCT length were significant nonsuitability risk factors for Terumo Aortic aBranch in multivariable analysis. No associations were found for Cook Medical device. The outcomes were tested in the entire cohort demonstrating a global suitability of 82.9%, increasing to 86.3% when ignoring minor IFUs. VBX was anatomically suitable to use in BCT in 73.2% of patient BCTs.

CONCLUSIONS

aBranch devices are anatomically suitable in a vast majority of patients (86%) undergoing hybrid TEVAR. The innominate artery seems eligible for incorporation with VBX in almost two-thirds of patients. This mating stent may help to overcome some minor IFU restrictions.

Outcomes of the Gore Excluder Iliac Branch Endoprosthesis for Japanese Patients With Aortoiliac Aneurysms: A Study Based on J-Preserve Registry

PURPOSE

To evaluate the clinical utility of the Gore Excluder iliac branch endoprosthesis (IBE) for Japanese patients with aortoiliac aneurysms.

MATERIALS AND METHODS

This was a multicenter retrospective cohort study (J-Preserve Registry). Patients undergoing endovascular aortic repair using the Gore Excluder IBE for aortoiliac aneurysms between August 2017 and June 2020 were enrolled. Data pertaining to the baseline and anatomical characteristics, technical details, and clinical outcomes were collected from each institution. The primary endpoints were technical success, IBE-related complications, and reinterventions. Secondary endpoints were mortality, aneurysm size change, and reintervention during follow-up. Technical success was defined as accurate deployment of the IBE without type Ib, Ic, or III endoleaks on the IBE sides on completion angiography. A change in aneurysm size of 5 mm or more was taken to be a significant change.

RESULTS

We included 141 patients with 151 IBE implantations. Sixty-five IBE implantations (43.0%) had at least one instruction for use violation. Twenty-two patients (15.6%) required internal iliac artery (IIA) embolization for external iliac artery extension on the contralateral side. Of 151 IBE implantations, 19 exhibited IIA branch landing zones due to IIA aneurysms. Mean maximum and proximal common iliac artery (CIA) diameters were 32.9±9.9 mm and 20.5±6.9 mm, respectively. The mean CIA length was 59.1±17.1 mm. The IIA landing diameter and length were 9.0±2.3 mm and 33.8±14.6 mm. The overall technical success rate was 96.7%. There were no significant differences in IBE-related complications (2.3% vs 5.3%, p=0.86) or IBE-related reinterventions (1.5% vs 5.3%, p=0.33) between the IIA trunk and IIA branch landing groups. The mean follow-up period was 635±341 days. The all-cause mortality rate was 5.0%. There were no aneurysm-related deaths or ruptures during the follow-up. Most patients (95.7%) had sac stability or shrinkage.

CONCLUSION

The Gore Excluder IBE was safe and effective for Japanese patients in the midterm. Extending the IIA device into the distal branches of the IIA was acceptable, which may permit extending indications for endovascular aortic aneurysm repair of aortoiliac aneurysms to more complex lesions.

CLINICAL IMPACT

This study suggests clinical benefits of the Gore Excluder IBE for Japanese patients, despite 43% of the IBE implantations having at least one IFU violation.

Bacteriophages for the treatment of pseudomonas-infected vascular prosthesis

We present a case report detailing therapeutic application of two lytic antipseudomonal bacteriophages to treat a chronic relapsing Pseudomonas aeruginosa infection of a prosthetic aortic graft. As there are currently no Danish laboratories offering phages for clinical therapy, and this case, to our knowledge represents the first applied phage therapy in Denmark, the practical and regulatory aspects of offering this treatment option in Denmark is briefly reviewed along with the clinical case.

Effect of the pipeline embolization device placement on branching vessels in anterior circulation: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Pipeline embolization device (PED) is widely used in intracranial aneurysms, and the scope of applications for the PED, which is frequently used to treat cerebral aneurysms, is also growing. It has some effect on branching vessels as a result of its inherent properties. The effects of PED on the complications rate and branching vessels blockage have not yet been thoroughly investigated.

OBJECTIVE

We conducted a systematic review searching reports from multiple databases on PED use for intracranial aneurysms, and analyzed the influence of PED on the occlusion rate of different branching vessels, and the influence of the amount of PED on the occlusion rate of branching vessels by meta-analysis.

METHODS

We searched the literature using PUBMED, Web of Science, and OVID databases until August 2023. Inclusion criteria were that the study used only PED, included at least 10 patients, and recorded branching vessels occlusion rates, mortality, and neurological complications.

RESULTS

Nine studies were analyzed consisting of 706 patients with 986 side branches. The results of the meta-analysis showed that application of more than one PED did not significantly elevate the rate of branching vessels occlusion compared to application of one PED (OR = 0.70; 95% CI: 0.34 to 1.43; P = 0.33). In the comparison of branching vessels occlusion rates in the anterior circulation, the anterior cerebral artery (ACA) had a significantly higher occlusion rate compared to the ophthalmic artery (OphA) (OR = 6.54; 95% CI: 3.05 to 14.01; P < 0.01), ACA also had a higher occlusion rate compared to the anterior choroidal artery (AchA) (OR = 15.44; 95% CI: 4.11 to 57.94 P < 0.01), ACA versus posterior communicating artery (PcomA) occlusion rate difference was not statistically significant (OR = 2.58; 95% CI: 0.63 to 12.82; P = 0.17), OphA versus AchA occlusion rate difference was not statistically significant (OR = 2.56; 95% CI: 0.89 to 7.38; P = 0.08), and the occlusion rate was significantly higher for PcomA compared to AchA (OR = 7.22; 95% CI: 2.49 to 20.95; P < 0.01) and lower for OphA compared to PcomA (OR = 0.33; 95% CI: 0.19 to 0.55; P < 0.01).

CONCLUSION

The meta-analysis shows that use of multiple PEDs did not significantly increase the occlusion rate of branching vessels, and the larger the diameter of branching vessels covered by PED, the higher the occlusion rate of branching vessels. However, the incidence of complications is low after branching vessels occlusion in anterior circulation, which is related to the collateral circulation compensation of the branching vessels.

Temporal Changes in the Surface Chemistry and Topography of Reactive Ion Plasma-Treated Poly(vinyl alcohol) Alter Endothelialization Potential

Synthetic small-diameter vascular grafts (<6 mm) are used in the treatment of cardiovascular diseases, including coronary artery disease, but fail much more readily than similar grafts made from autologous vascular tissue. A promising approach to improve the patency rates of synthetic vascular grafts is to promote the adhesion of endothelial cells to the luminal surface of the graft. In this study, we characterized the surface chemical and topographic changes imparted on poly(vinyl alcohol) (PVA), an emerging hydrogel vascular graft material, after exposure to various reactive ion plasma (RIP) surface treatments, how these changes dissipate after storage in a sealed environment at standard temperature and pressure, and the effect of these changes on the adhesion of endothelial colony-forming cells (ECFCs). We showed that RIP treatments including O2, N2, or Ar at two radiofrequency powers, 50 and 100 W, improved ECFC adhesion compared to untreated PVA and to different degrees for each RIP treatment, but that the topographic and chemical changes responsible for the increased cell affinity dissipate in samples treated and allowed to age for 230 days. We characterized the effect of aging on RIP-treated PVA using an assay to quantify ECFCs on RIP-treated PVA 48 h after seeding, atomic force microscopy to probe surface topography, scanning electron microscopy to visualize surface modifications, and X-ray photoelectron spectroscopy to investigate surface chemistry. Our results show that after treatment at higher RF powers, the surface exhibits increased roughness and greater levels of charged nitrogen species across all precursor gases and that these surface modifications are beneficial for the attachment of ECFCs. This study is important for our understanding of the stability of surface modifications used to promote the adhesion of vascular cells such as ECFCs.

Endothelium-Mimicking Bilayer Vascular Grafts with Dual-Releasing of NO/H2S for Anti-Inflammation and Anticalcification

Vascular complications caused by diabetes impair the activities of endothelial nitric oxide synthase (eNOS) and cystathionine γ-lyase (CSE), resulting in decreased physiological levels of nitric oxide (NO) and hydrogen sulfide (H2S). The low bioavailability of NO and H2S hinders the endothelialization of vascular grafts. In this study, endothelium-mimicking bilayer vascular grafts were designed with spatiotemporally controlled dual releases of NO and H2S for in situ endothelialization and angiogenesis. Keratin-based H2S donor was synthesized and electrospun with poly(l-lactide-co-ε-caprolactone) (PLCL) as the outer layer of the graft to release H2S. Hyaluronic acid, one of the major glycosaminoglycans in endothelial glycocalyx, was complexed with Cu ions as the inner layer to mimic glutathione peroxidase (GPx) and maintain long-term physiological NO flux. The synergistic effects of NO and H2S of bilayer grafts selectively promoted the regeneration and migration of human umbilical vascular endothelial cells (HUVECs), while inhibiting the overproliferation of human umbilical artery smooth muscle cells (HUASMCs). Bilayer grafts could effectively prevent vascular calcification, reduce inflammation, and alleviate endothelial dysfunction. The in vivo study in a rat abdominal aorta replacement model for 1 month showed that the graft had a good patency rate and had potential for vascular remodeling in situ.

Development of tissue-engineered vascular grafts from decellularized parsley stems

Cardiovascular diseases are mostly associated with narrowing or blockage of blood vessels, and it is the most common cause of death worldwide. The use of vascular grafts is a promising approach to bypass or replace the blocked vessels for long-term treatment. Although autologous arteries or veins are the most preferred tissue sources for vascular bypass, the limited presence and poor quality of autologous vessels necessitate seeking alternative biomaterials. Recently, synthetic grafts have gained attention as an alternative to autologous grafts. However, the high failure rate of synthetic grafts has been reported primarily due to thrombosis, atherosclerosis, intimal hyperplasia, or infection. Thrombosis, the main reason for failure upon implantation, is associated with damage or absence of endothelial cell lining in the vascular graft's luminal surface. To overcome this, tissue-engineered vascular grafts (TEVGs) have come into prominence. Alongside the well-established scaffold manufacturing techniques, decellularized plant-based constructs have recently gained significant importance and are an emerging field in tissue engineering and regenerative medicine. Accordingly, in this study, we demonstrated the fabrication of tubular scaffolds from decellularized parsley stems and recellularized them with human endothelial cells to be used as a potential TEVG. Our results suggested that the native plant DNA was successfully removed, and soft tubular biomaterials were successfully manufactured via the chemical decellularization of the parsley stems. The decellularized parsley stems showed suitable mechanical and biological properties to be used as a TEVG material, and they provided a suitable environment for the culture of human endothelial cells to attach and create a pseudo endothelium prior to implantation. This study is the first one to demonstrate the potential of the parsley stems to be used as a potential TEVG biomaterial.

Surgical management of abdominal aortic graft infection: network meta-analysis

BACKGROUND

A paucity of evidence exists regarding the optimal management for abdominal aortic graft infection. The aim of this paper was to assess short- and long-term outcomes following different surgical options in aortic graft infection patients.

METHODS

Medline, Embase and the Cochrane Library were searched from inception to February 2023. Network meta-analysis was performed using a frequentist method. Patients were divided into four treatment groups: complete graft removal with in situ repair, complete graft removal with extra-anatomic repair, partial graft removal with in situ repair and partial graft removal with extra-anatomic repair. The mortality rate at 30-days and 1-year was the primary outcome. Secondary outcomes were longer-term mortality rate, primary patency and reinfections. For included RCTs, the Cochrane risk-of-bias tool was utilized to assess the risk of bias. The methodological quality of cohort studies was evaluated using the Newcastle-Ottawa scale.

RESULTS

Among 4559 retrieved studies, 22 studies with 1118 patients (11 multi-arm and 11 single-arm studies) were included. Patients received complete graft removal with in situ repair (N = 852), partial graft removal with in situ repair (N = 36), complete graft removal with extra-anatomic repair (N = 228) and partial graft removal with extra-anatomic repair (N = 2). Both network meta-analysis results and pooled results of multi- and single-arm cohorts indicated that partial graft removal with in situ repair has the lowest 30-day and 1-year mortality rates (0% and 6.1% respectively), followed by complete graft removal with in situ repair (11.9% and 23.8% respectively) and complete graft removal with extra-anatomic repair (16.6% and 41.4% respectively). In addition, complete graft removal with in situ repair had a lower 3-year (complete graft removal with in situ repair versus complete graft removal with extra-anatomic repair: 32.1% versus 90%) and 5-year (complete graft removal with in situ repair versus complete graft removal with extra-anatomic repair: 45.6% versus 67.9%) mortality rate when compared with complete graft removal with extra-anatomic repair. Patients in the complete graft removal with in situ repair group had the lowest reinfections (8%), followed by partial graft removal with in situ repair (9.3%) and complete graft removal with extra-anatomic repair (22.4%).

CONCLUSION

Partial graft removal with in situ repair was associated with lower 30-day and 1-year mortality rates when compared with complete graft removal with in situ repair and complete graft removal with extra-anatomic repair. Partial graft removal with in situ repair might be a feasible treatment for specific aortic graft infection patients.

Optimal stent length and distal positioning of frozen elephant trunks deployed from the aortic zone 0 for type A acute aortic dissection

OBJECTIVES

To investigate the optimal stent length and distal positioning of frozen elephant trunks (FETs) in patients with type A acute aortic dissection (TAAD).

METHODS

Between October 2014 and April 2021, 191 patients (FET-150 group: 37 patients; stent length, 150 mm; 66.3 ± 12.6 years and FET-non-150 group: 154 patients; 60, 90, or 120 mm; 64.1 ± 12.5 years) underwent total arch repair with FETs for TAAD using the "zone 0 arch repair" strategy. In the FET-150 group, the proximal stent end was positioned at the innominate artery origin of the arch. In the FET-non-150 group, the distal stent end was to be positioned just proximal to the aortic valve level using transesophageal echocardiography. The proximal end of the non-stented FET part was sutured to an arch graft together with the aortic wall at 1 to 2 cm proximal to the innominate artery origin.

RESULTS

Distal stent ends were positioned at the thoracic vertebrae (Th) 4-5, 6-7, 8-9, and 10 levels in 0 (0%), 12 (32.4%), 25 (67.6%), and 0 (0%) patients, respectively, in the FET-150 group, and in 6 (3.9%), 98 (63.6%), 49 (31.8%), and 1 (0.7%), respectively, in the FET-non-150 group. No between-group difference in postoperative mortality was noted. The incidence of postoperative residual distal malperfusion and new-onset spinal cord ischemia in the FET-150 versus FET-non-150 groups were 2.7% versus 6.5% (P = .62) and 0% versus 1.9% (P = 1.00), respectively.

CONCLUSIONS

FET positioning with the distal stent end at around Th 8 can reduce residual distal malperfusion when a FET with a 150-mm stent is deployed from the aortic zone 0 in patients with TAAD undergoing total arch repair.

Novel Technique for Intentional Occlusion of Directional Branches During Complex Endovascular Aortic Repair Using Microvascular Plugs

PURPOSE

To demonstrate the feasibility and outcomes of using the microvascular plug (MVP) for intentional occlusion of directional branches (DB) during complex endovascular aortic procedures.

CASE REPORT

Two patients were treated with the off-the-shelf four-branched Zenith t-Branch thoracoabdominal stent-graft (Cook Medical, Bloomington, Ind). In both cases, the renal arteries (on one side in patient #1 and on both sides in patient #2, respectively) were occluded at time of index intervention. Preoperative planning included the intentional occlusion of each DB with one 7Q-MVP. Technical success was achieved in all cases and maintained at mid-term follow-up (12 months and 36 months, respectively).

CONCLUSIONS

Use of the MVP appears to be feasible and effective for intentional occlusion of DB during complex endovascular aortic repair. This novel and simple technique may present some unique technical advantages, allowing precise placement of the device while avoiding extension using a bridging stent and DB cannulation with larger sheaths.

Development of heparinized and hepatocyte growth factor-coated acellular scaffolds using porcine carotid arteries

Tissue-engineered blood vessel substitutes have been developed due to the lack of suitable small-diameter vascular grafts. Xenogeneic extracellular matrix (ECM) scaffolds have the potential to provide an ideal source for off-the-shelf vascular grafts. In this study, porcine carotid arteries were used to develop ECM scaffolds by decellularization and coating with heparin and hepatocyte growth factor (HGF). After decellularization, cellular and nucleic materials were successfully removed with preservation of the main compositions (collagen, elastin, and basement membrane) of the native ECM. The ultimate tensile strength, suture strength, and burst pressure were significantly increased after cross-linking. Pore size distribution analysis revealed a porous structure within ECM scaffolds with a high distribution of pores larger than 10 μm. Heparinized scaffolds exhibited sustained release of heparin in vitro and showed potent anticoagulant activity by prolonging activated partial thromboplastin time. The scaffolds showed an enhanced HGF binding capacity as well as a constant release of HGF as a result of heparin modification. When implanted subcutaneously in rats, the modified scaffolds revealed good biocompatibility with enzyme degradation resistance, mitigated immune response, and anti-calcification. In conclusion, heparinized and HGF-coated acellular porcine carotid arteries may be a promising biological scaffold for tissue-engineered vascular grafts.

AneuGuide™ software-assisted vs. manual measurements in sizing for pipeline embolization device: An agreement study

Sizing of flow diverters (FDs) is a challenging task in the treatment of intracranial aneurysms due to their foreshortening behavior. The purpose of this study is to evaluate the difference between the sizing results from the AneuGuide™ software and from conventional 2D measurement. Ninety-eight consecutive patients undergoing pipeline embolization device (PED) treatment between October 2018 and April 2023 in the First Medical Center of Chinese PLA General Hospital (Beijing, China) were retrospectively analyzed. For all cases, the optimal PED dimensions were both manually determined through 2D measurements on pre-treatment 3D-DSA and computed by AneuGuide™ software. The inter-rater reliability between the two sets of sizing results for each methodology was analyzed using intraclass correlation coefficient (ICC). The degree of agreement between manual sizing and software sizing were analyzed with the Bland-Altman plot and Pearson's test. Differences between two methodologies were analyzed with Wilcoxon signed rank test. Statistical significance was defined as p < 0.05. There was better inter-rater reliability between AneuGuide™ measurements both for diameter (ICC 0.92, 95%CI 0.88-0.95) and length (ICC 0.93, 95%CI 0.89-0.96). Bland-Altman plots showed a good agreement for diameter selection between two methodologies. However, the median length proposed by software group was significantly shorter (16 mm versus 20 mm, p < 0.001). No difference was found for median diameter (4.25 mm versus 4.25 mm). We demonstrated that the AneuGuide™ software provides highly reliable results of PED sizing compared with manual measurement, with a shorter stent length. AneuGuide™ may aid neurointerventionalists in selecting optimal dimensions for FD treatment.

Heparin-Bonded Expanded Polytetrafluoroethylene Is a Solution for Infrapopliteal Revascularization in the Absence of an Adequate Autologous Vein Graft

BACKGROUND

To analyze the outcomes of heparin-bonded expanded polytetrafluoroethylene (HePTFE) graft as an alternative conduit in infrapopliteal revascularization of chronic limb-threatening ischemia (CLTI) in the absence of an autologous vein conduit.

METHODS

A single-center retrospective analysis of patients with CLTI submitted to infrapopliteal bypasses with autologous vein graft (VEIN group) or HePTFE graft (HePTFE group) was implemented. Primary end points were freedom from CLTI at 12 months and recurrence of CLTI at 3 years. Secondary end points included freedom from major amputation, amputation-free survival (AFS), survival, and primary (PP) and secondary patency (SP) rates at 3 years of follow-up.

RESULTS

A total of 348 limbs submitted to infrapopliteal bypasses, 214 with venous graft and 134 with HePTFE graft, were followed-up for a median of 25 months. Most patients of the HePTFE group were male (69%), with a median age of 76 years (interquartile range [IQR] 15). Fifty-nine percent of the limbs of the HePTFE group had Wound grade ≥2, being 46% of them infected. Eighty-eight percent were GLASS stage III. Freedom from CLTI was not significantly different between HePTFE and VEIN groups (75% vs. 84%, adjusted hazard ratio [aHR] 0.88, confidence interval [CI] 0.66-1.18, P = 0.401). Recurrence of CLTI was higher in the HePTFE group (42% vs.18% at 3 years; aHR 2.82, CI 1.59-5.00, P < 0.001). The VEIN group achieved higher rates of freedom from major amputation (87% vs.69% at 3 years; aHR 2.21, CI 1.31-3.75, P = 0.003) and AFS (59% vs. 37% at 3 years; aHR 1.39, CI 1.02-1.88, P = 0.036), but no significance in survival (aHR 1.10, CI 0.72-1.66, P = 0.667). Patency rates were inferior in the HePTFE group, with 2-year PP and SP rates of 52% vs. 74%, and 76% vs. 90%, respectively (PP: aHR 1.70, CI 1.11-2.59, P = 0.014; SP: aHR 2.51, CI 1.42-4.42, P = 0.001).

CONCLUSIONS

Infrapopliteal bypass with autologous vein graft is the gold standard to treat CLTI limbs. HePTFE graft should be regarded as an alternative for complex infrapopliteal revascularization when lacking an autologous vein conduct.

National UK Survey of Radiation Doses During Endovascular Aortic Interventions

PURPOSE

Endovascular aortic repair (EAR) interventions, endovascular abdominal aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR), are associated with significant radiation exposures. We aimed to investigate the radiation doses from real-world practice and propose diagnostic reference level (DRL) for the UK.

MATERIALS AND METHODS

Radiation data and essential demographics were retrospectively collected from 24 vascular and interventional radiology centres in the UK for all patients undergoing EAR-standard EVAR or complex, branched/fenestrated (BEVAR/FEVAR), and TEVAR-between 2018 and 2021. The data set was further categorised according to X-ray unit type, either fixed or mobile. The proposed national DRL is the 75th percentile of the collective medians for procedure KAP (kerma area product), cumulative air kerma (CAK), fluoroscopy KAP and CAK.

RESULTS

Data from 3712 endovascular aortic procedures were collected, including 2062 cases were standard EVAR, 906 cases of BEVAR/FEVAR and 509 cases of TEVAR. The majority of endovascular procedures (3477/3712) were performed on fixed X-ray units. The proposed DRL for KAP was 162 Gy cm2, 175 Gy cm2 and 266 Gy cm2 for standard EVAR, TEVAR and BEVAR/FEVAR, respectively.

CONCLUSION

The development of DRLs is pertinent to EAR procedures as the first step to optimise the radiation risks to patients and staff while maintaining the highest patient care and paving the way for steps to reduce radiation exposures.

Physicochemical, in vitro and in vivo evaluation of VEGF loaded PCL-mPEG and PDGF loaded PCL-Chitosan dual layered vascular grafts

The present study has attempted to evaluate the endothelialization and smooth muscle regeneration efficiency of a novel dual-layer small-diameter vascular graft. Two types of layers (PCL-mPEG-VEGF and PCL-Chitosan-PDGF) were fabricated to find out the best layer giving endothelialization support for the lumen and unique contractile function for outer layer of blood vessels. Platelet-derived growth factor (PDGF) and chitosan were immobilized onto PCL surface by aminolysis-based surface modification technique. Besides, Poly (ethylene glycol) methyl ether (mPEG) and vascular endothelial growth factor (VEGF) were directly blended with PCL. Morphological analysis of membranes ensured consistency of average fibers diameter with native extracellular matrix. A favorable interaction of PCL-mPEG-VEGF with cow pulmonary endothelial cells (CPAEs) and PCL-Chitosan-PDGF with rat bone marrow mesenchymal stem cells (RBMSCs) was obtained during in vitro study. Controlled growth factor release patterns were found from both layers. Further, PCL-mPEG-VEGF exhibited endothelial markers expression properties from RBMSCs. Up-regulation of SMCs markers expression was significantly ensured by the PCL-Chitosan-PDGF membrane. Thus, PCL-mPEG-VEGF and PCL-Chitosan-PDGF were preferred as inner and outer layers respectively of a finally prepared tubular hybrid tissue engineered small diameter vascular graft. Finally, the dual-layer vascular graft was implanted onto a rat abdominal aorta model for 2 months. The extracted samples exhibited the presence of endothelial marker (ICAM 1) in the inner layer and smooth muscle cell marker (αSMA) in the outer layer as well as substantial amount of collagen deposition was observed in the both layers.

Long Term Outcomes and Durability of Fenestrated Endovascular Aneurysm Repair: A Meta-analysis of Time to Event Data

OBJECTIVE

Despite widespread use, long term outcomes for fenestrated endovascular aneurysm repair (FEVAR) are uncertain. This meta-analysis reports long term survival, freedom from re-intervention, target vessel patency, and one year sac regression after FEVAR.

DATA SOURCES

Systematic review and meta-analysis to pool time to event data according to PRISMA guidelines. The study was registered with the international prospective register of systematic reviews (PROSPERO) (ID: CRD42023401468).

REVIEW METHODS

Medline, Embase, and Cochrane databases were searched from 1992 - 2023; articles were independently screened by two authors. Publication of complete time to event data for any outcome of interest was an inclusion criterion. Raw Kaplan-Meier probabilities were directly extracted from published curves and pooled by random effects. Risk of bias was assessed using ROBINS I and certainty with GRADE.

RESULTS

A total of 3 569 records were retrieved, 2 869 screened after duplicate removal, yielding 37 included studies (n = 4 371). The pooled mean age was 73.2 years (interquartile range [IQR] 72.2, 73.7) and 87.4% were male (95% confidence interval [CI] 85.8 - 88.9). Pooled Kaplan-Meier estimated probabilities of survival (n = 34 studies, n = 4 192 patients) at one, three, and five years were 91.6% (95% CI 90.2 - 92.9), 80.8% (95% CI 78.0 - 83.2), and 65.1% (95% CI 60.9 - 69.1). For freedom from re-intervention (n = 24, n = 3 211 patients) at one, three, and five years these were 90.2% (95% CI 87.3 - 92.7), 80.9% (95% CI 76.5 - 84.9), and 73.8% (95% CI 67.1 - 79.6). For target vessel patency (n = 13, n = 5805 target vessels) at one, three, and five years, these were 96.6% (95% CI 94.9 - 98.0), 94.5% (95% CI 91.7 - 96.7), and 93.1% (95% CI 89.3 - 96.0). Pooled estimate of sac regression (n = 8, n = 560) at one year was 40.2% (95% CI 28.9 - 52.7). Risk of bias was judged as moderate in 11 studies and low for the remaining 26.

CONCLUSION

There are moderate to low certainty data supporting reasonable long term outcome estimates following fenestrated endovascular aneurysm repair. Beyond five years there is a lack of data in the literature.

Impact of post-implantation syndrome on outcomes in acute type B aortic syndrome patients undergoing endovascular repair

Background: The aim of this study was to explore the impact of post-implantation syndrome (PIS) on prognosis outcomes in individuals with type B acute aortic syndrome (AAS) undergoing thoracic endovascular aortic repair (TEVAR). Patients and methods: Data from type B AAS individuals who underwent TEVAR from January 2014 to April 2021 were retrospectively reviewed. Study subjects were divided into PIS and non-PIS (nPIS) groups and postoperative clinical outcomes were analyzed. Results: Our study cohort of 74 individuals with type B AAS included 40 aortic dissection (AD), 30 intramural hematoma (IMH), 4 penetrating aortic ulcer (PAU). The incidence of PIS was 14.9%. No statistically significant differences were found in baseline characteristics. The left subclavian artery (LSCA) reconstruction was performed more frequently among the PIS group (45.5% vs 9.5%, p=.008). Major adverse events (MAE) tended to be more frequent in the PIS group, but the difference was not significant (27.3% vs 22.2%, p=.707). At 2-year follow-up, results were comparable between the two groups. Kaplan-Meier analysis showed that PIS was not associated with a higher incidence of mortality, endoleak, new-onset AD, or stroke. A baseline neutrophil-to-lymphocyte ratio (NLR) >10.3 was associated with greater incidence of MAE. In individuals with IMH, better aortic remodeling evaluated by lower total aortic diameter/true lumen diameter (TAD/TLD) was achieved in the nPIS group (1.23±0.10 vs 1.43±0.07, p<.001), and a TAD/TLD ratio >1.32 was associated with significantly more MAE. Cox multivariate regression analysis also showed that a postoperative TAD/TLD ratio >1.32 was an independent risk factor for MAE (OR, 11.36; 95% CI, 1.53-84.26; p=.017). Conclusions: PIS was associated with a trend toward a higher incidence of MAE after TEVAR. In individuals with IMH, a TAD/TLD ratio >1.32 was an independent predictor of postoperative MAE.

Current Medicare reimbursement for complex endovascular aortic repair is inadequate based on results from a multi-institutional cost analysis

OBJECTIVE

Complex endovascular juxta-, para- and suprarenal abdominal aortic aneurysm repair (comEVAR) is frequently accomplished with commercially available fenestrated (FEVAR) devices or off-label use of aortoiliac devices with parallel branch stents (chEVAR). We sought to evaluate the implantable vascular device costs incurred with these procedures as compared with standard Medicare reimbursement to determine the financial viability of comEVAR in the modern era.

METHODS

Five geographically distinct institutions with high-volume, complex aortic centers were included. Implantable aortoiliac and branch stent device cost data from 25 consecutive, recent, comEVAR in the treatment of juxta-, para-, and suprarenal aortic aneurysms at each center were analyzed. Cases of rupture, thoracic aneurysms, reinterventions, and physician-modified EVAR were excluded, as were ancillary costs from nonimplantable equipment. Data from all institutions were combined and stratified into an overall cost group and two, individual cost groups: FEVAR or chEVAR. These groups were compared, and each respective group was then compared with weighted Medicare reimbursement for Diagnosis-Related Group codes 268/269. Median device costs were obtained from an independent purchasing consortium of >3000 medical centers, yielding true median cost-to-institution data rather than speculative, administrative projections or estimates.

RESULTS

A total of 125 cases were analyzed: 70 FEVAR and 53 chEVAR. Two cases of combined FEVAR/chEVAR were included in total cost analysis, but excluded from direct FEVAR vs chEVAR comparison. Median Medicare reimbursement was calculated as $35,755 per case. Combined average implantable device cost for all analyzed cases was $28,470 per case, or 80% of the median reimbursement ($28,470/$35,755). Average FEVAR device cost per case ($26,499) was significantly lower than average chEVAR cost per case ($32,122; P < .002). Device cost was 74% ($26,499/$35,755) of total reimbursement for FEVAR and 90% ($32,122/$35,755) for chEVAR.

CONCLUSIONS

Results from this multi-institutional analysis show that implantable device cost alone represents the vast majority of weighted total Medicare reimbursement per case with comEVAR, and that chEVAR is significantly more costly than FEVAR. Inadequate Medicare reimbursement for these cases puts high-volume, high-complexity aortic centers at a distinct financial disadvantage. In the interest of optimizing patient care, these data suggest a reconsideration of previously established, outdated, Diagnosis-Related Group coding and Medicare reimbursement for comEVAR.

Results of the Chimney Technique in a Community Hospital

BACKGROUND

The chimney technique, fenestrated or branched endovascular aortic repair are endovascular options in patients with a juxtarenal, suprarenal or type IV thoraco-abdominal aneurysm. The chimney technique has specific advantages and disadvantages. A retrospective single center study was performed to describe the results.

PATIENTS AND METHODS

All consecutive patients in whom the chimney technique was used between 1th January 2011 and 31th December 2020 were included. We excluded patients who needed a revision of an existing EVAR and patients with a para-anastomotic aneurysm. Outcomes were reported in accordance with the reporting standards.

RESULTS

38 Patients were included in the study, a total of 59 chimney grafts were deployed. At a median follow-up duration of 26.6 months, there were 9 patients with occlusion of the chimney graft. In 1 patient an iliac renal bypass was performed. In the other patients the renal function stabilized and no further therapy was necessary. All chimneys in the mesenteric arteries remained patent. Gutter endoleak was seen in 5 patients, 3 patients were successfully treated and in the other 2 patients the gutter endoleak disappeared spontaneously.

CONCLUSIONS

Conclusions should be drawn carefully as this is a retrospective non-comparative study. Results from 38 patients treated with the chimney technique are presented. Chimney graft occlusion rate was 15.3% at the end of follow-up. However, the majority (77.8%) of the occluded stents were self-expandable stents, stressing the importance of selecting the right devices.

Aneurysm Sac Shrinkage After EVAR Can Lead to Complications: A Case Report of Complete Endograft Thrombosis Due to Kinking

BACKGROUND

Bilateral limb occlusion after endovascular repair of abdominal aortic aneurysms (EVAR) is an uncommon entity. The relationship between graft kinking and unilateral limb occlusion is widely described in the literature. Our aim is to report a case of complete endograft thrombosis due to bilateral limb kinking secondary to aneurysm sac shrinkage, treated by endovascular means.

CASE REPORT

A 67 year-old male with history of EVAR with an Incraft® endograft (Cordis, Bridgewater, NJ, USA) four years before, presented at the emergency department with disabling claudication of the right lower extremity and a better tolerated 10-month left extremity claudication. Complete endograft thrombosis with bilateral limb kinking and a remarkable reduction of the aneurysm sac was observed in the computed tomography angiography. An endovascular repair was performed, through bilateral open femoral access and with angiographic control through percutaneous left brachial access. Bilateral recanalization was achieved and the endograft was re-lined with two 10x150 mm Viabahn (WL Gore & Ass., Flagstaff, AZ, USA). Both sides were extended with a 11 × 50 mm Viabahn (WL Gore & Ass., Flagstaff, AZ, USA). The final angiographic control showed bilateral patency with no residual stenosis and the patient recovered distal pulses. Follow-up showed complete patency and no complications at 17 months.

CONCLUSIONS

Bilateral limb occlusion is a rare complication with technically challenging treatment options. Aneurysm sac shrinkage can affect the endograft configuration, leading to limb distortion and occasionally to bilateral limb occlusion after EVAR. Special attention should be put on imaging follow-up to detect these complications before occlusion occurs.

Intravascular Ultrasound in the Detection of Bridging Stent Graft Instability During Fenestrated and Branched Endovascular Aneurysm Repair Procedures: A Multicentre Study on 274 Target Vessels

OBJECTIVE

The use of intravascular ultrasound (IVUS) reduces contrast medium use and radiation exposure during conventional endovascular aneurysm repair (EVAR). The aim of this study was to evaluate the safety and efficacy of IVUS in detecting bridging stent graft (bSG) instability during fenestrated and branched EVAR (F/B-EVAR).

METHODS

This was a prospective observational multicentre study. The following outcomes were evaluated: (1) technical success of the IVUS in each bSG, (2) IVUS findings compared with intra-operative angiography, (3) incidence of post-operative computed tomography angiography (CTA) findings not detected with IVUS, and (4) absence of IVUS related adverse events. Target visceral vessel (TVV) instability was defined as any branch or fenestration issues requiring an additional manoeuvre or re-intervention. Any IVUS assessment that detected stenosis, kinking, or any geometric TVV issue was considered to be branch instability. All procedures were performed in ad hoc hybrid rooms.

RESULTS

Eighty patients (69% males; median age 72 years; interquartile range 59, 77 years) from four aortic centres treated with F/B-EVAR between January 2019 and September 2021 were included: 70 BEVAR (21 off the shelf; 49 custom made), eight FEVAR (custom made), and two F/B-EVAR (custom made), for a total of 300 potential TVVs. Two TVVs (0.7%) were left unstented and excluded from the analysis. The TVVs could not be accessed with the IVUS catheter in seven cases (2.3%). Furthermore, 17 (5.7%) TVVs could not be examined due to a malfunction of the IVUS catheter. The technical success of the IVUS assessment was 91.9% (274/298), with no IVUS related adverse events. Seven TVVs (2.5%) showed signs of bSG instability by means of IVUS, leading to immediate revisions. The first post-operative CTA at least 30 days after the index procedure was available in 268 of the 274 TVVs originally assessed by IVUS. In seven of the 268 TVVs (2.6%) a re-intervention became necessary due to bSG instability.

CONCLUSION

This study suggests that IVUS is a safe and potentially valuable adjunctive imaging technology for intra-operative detection of TVV instability. Further long term investigations on larger cohorts are required to validate these promising results and to compare IVUS with alternative technologies in terms of efficiency, radiation exposure, procedure time, and costs.

Patency and Durability of Stent Grafts Placed in the Dialysis Circuit Cannulation Zone

PURPOSE

To investigate the safety, durability, and patency rates of stent grafts (SGs) placed in the cannulation zone of hemodialysis access circuits.

MATERIALS AND METHODS

From April 2020 to April 2023, all procedures with SGs placed in the cannulation zone were retrospectively analyzed. A total of 40 patients (25 men and 15 women) with SGs placed in the cannulation zone were included in the study. Mean age of the patients was 70 years. The Covera covered stent (BD, Franklin Lakes, New Jersey) was used in all cases. Of these, 26 were arteriovenous (AV) fistulae and 14 were AV grafts. SGs were placed for residual stenosis, perforation, aneurysm, and thrombosis. Follow-up outcomes were determined using follow-up angiographic images and included primary patency, primary-assisted patency, and secondary patency.

RESULTS

The primary patency of the target lesion was 89% (SD ± 5) and 74% (SD ± 8.4) at 6 and 12 months, respectively. The primary-assisted patency was 89% (SD ± 5.2) and 78% (SD ± 7.6) at 6 and 12 months, respectively. Secondary patency of the access circuit was 97% (SD ± 2.5) at both 6 and 12 months. Mean follow-up was 332 days (range, 28-661 days). All SGs were successfully cannulated for hemodialysis. No cases of stent fracture or stent infection were observed during follow-up.

CONCLUSIONS

SGs placed for cannulation zone pathologies can be safely cannulated for dialysis and have adequate short- and mid-term patency rates.

Prosthetic Conduit Use Does Not Adversely Impact Outcomes after Open Repair of Popliteal Artery Aneurysms

BACKGROUND

Single segment, greater saphenous vein (GSV) conduit is considered the optimal bypass conduit among patients undergoing bypass surgery for peripheral artery disease (PAD). While this data has been extrapolated to patients undergoing bypass for popliteal artery aneurysms (PAAs), the pathophysiology of PAA is inherently different when compared to PAD, and the impact of conduit type on long-term outcomes after open repair of PAA remains unclear.

METHODS

A multicenter database of five regional hospitals was retrospectively reviewed for all patients with PAA undergoing open surgical repair. Data were collected on demographic information, operative details, medications, and postoperative outcomes. Kaplan-Meier curves were used to compare freedom from major adverse limb events (MALE) following GSV versus prosthetic bypass. Cox proportional hazards model was used to identify patient-level characteristics associated with MALE, which was defined as major ipsilateral limb amputation or reintervention for graft patency.

RESULTS

From 1999 to 2020, a total of 101 patients with PAA underwent open exclusion and bypass surgery. Median follow-up period was 4.2 years (interquartile range, 1.3-7.4 years), and complete data were available for 99 (98.0%) patients. The majority of patients were male (99.0%) and Caucasian (93.9%). Only 11.1% of procedures were emergent, with the remainder (88.9%) being elective. All patients underwent medial exposure with a below-knee popliteal bypass target (100%). Bypass conduits included GSV (69.7%), prosthetic conduit (28.3%), and 2 (2.0%) alternative conduits (one spliced arm vein, one cryopreserved vein). Patients undergoing prosthetic bypass were older (72 vs. 66 years, P = 0.001) and had similar rates of medical comorbidities. Compared with the GSV group, patients with prosthetic conduits were more frequently placed on postoperative anticoagulation (60.7% vs. 23.2%, P < 0.001). Conduit type did not impact postoperative complication rates (P = NS each). MALE rates were low overall (19.2% at 2 years), and similar when stratified by conduit type (log rank P = 0.47). On multivariable analysis, emergent bypass was associated with MALE (hazard ratio [HR] 5.73, 95% confidence interval [CI] 2.07-15.85, P < 0.001). Prosthetic conduit usage (HR 1.00, 95% CI, 0.40-2.51, P = 0.99) and postoperative anticoagulation (HR 1.02, 95% CI 0.42-2.50, P = 0.97) were not associated with MALE.

CONCLUSIONS

Open repair of PAA is associated with excellent long-term outcomes. Prosthetic bypass is a comparable alternative to autogenous conduit for below-knee popliteal bypass targets, and lack of suitable GSV should not prohibit open surgical repair when indicated.

Mid-term efficacy of castor stent and in situ fenestration stent in the treatment of type B aortic dissection involving the left subclavian artery: A retrospective single-center study

To evaluate the midterm efficacy of the Castor stent (CS) versus in situ fenestration (ISF) for reconstructing the left subclavian artery (LSA) in patients with type B aortic dissection (TBAD). Between July 2017 and July 2022, a total of 247 patients with TBAD were enrolled. One hundred thirty-seven patients were treated using CSs (group A), while the remaining 110 patients received ISFs (group B). Data of the two groups were retrospectively analyzed. The success rates of surgery were 99.3% and 95.5% in groups A and B (p = .053), There were no deaths during hospitalization. During surgery, group B showed a longer surgical duration [68.0 (66.0, 77.0) vs. 62.0 (59.0, 66.0) min, p < .001] and intraoperative fluoroscopy time [18.0 (16.0, 20.0) vs. 16.0 (14.0, 18.0) min, p < .001] than group A. The follow-up duration was similar for both groups (44.0 vs. 43.0 months, p = .877), and no patient died. Stent-related complications were significantly lower in group A than in group B (1.5% vs. 8.4%, p = .009). Group A had fewer instances entry flow (0.7% vs. 4.7%, p = .048) and stent stenosis (0.7% vs. 2.8%, p = .206) than group B. All reintervention cases (4.7%) were from group B (p = .011). The rate of false aortic lumen thrombosis was significantly higher in group A than in group B (84.6% vs. 72.9%, p = .024). Both CSs and ISFs are evidently safe, feasible, and effective in achieving positive early outcomes in patients undergoing treatment for TBAD. Notably, at midterm follow-up, CSs appeared to be superior to ISF in terms of reducing stent-related complications and minimizing the need for reintervention.

Outcomes of Fenestrated and Branched Endografts for Partial and Total Endovascular Repair of the Aortic Arch - A Systematic Review and Meta-Analysis

OBJECTIVE

Fenestrated and branched thoracic endovascular aortic repair (F/B-TEVAR) of the aortic arch is a viable approach in patients unsuitable for open repair. The aim was to summarise the published results of manufactured F/B-TEVAR devices for partial and total repair of the aortic arch, and to compare fenestrated with branched configurations.

DATA SOURCES

PubMed, Scopus and The Cochrane Library were searched for articles (2018 - 2021) about patients with elective, urgent, or emergency aortic requiring a proximal landing zone in the aortic arch (zone 0 - 1 - 2) and treated by F/B-TEVAR.

REVIEW METHODS

The systematic review and meta-analysis were performed according to the PRISMA guidelines. Open repair, supra-aortic trunk (SAT) debranching + standard TEVAR, and in situ physician modified and parallel grafts were excluded. Primary outcomes were technical success and 30 day mortality rate. Secondary outcomes were 30 day major adverse events, and overall survival and procedure related endpoints during follow up.

RESULTS

Of 458 articles screened, 18 articles involving 571 patients were selected. Indications for intervention were chronic dissections (50.1%), degenerative aneurysms (39.6%), penetrating aortic ulcers (7.4%), and pseudoaneurysms (2%). F-TEVAR, B-TEVAR, and F+B-TEVAR were used in 38.4%, 54.1%, and 7.5% of patients, respectively. Overall, technical success was 95.9% (95% confidence interval [CI] 0.93 - 0.97; I2 = 0%; p for heterogeneity (Het) = .77) and the 30 day mortality rate was 6.7% (95% CI 0.05 - 0.09; I2 = 0%; p Het = .66). No statistical differences were found comparing fenestrated with branched endografts, except for a higher rate of type I - III endoleaks in F-TEVAR (9.8% vs. 2.6%; p = .034). The overall survival rate and freedom from aortic related death at the one year follow up ranged between 82 - 96.4% and 94 - 94.7%, respectively. Thirteen and five studies were considered at moderate and high risk of bias, respectively.

CONCLUSION

F/B-TEVAR for the treatment of the aortic arch, according to experience in dedicated centres, now enjoys a satisfactory level of technical success together with a progressively reduced early mortality rate. There are several limitations, and further studies are needed to reach clearer conclusions.

Fabrication of heparinized bi-layered vascular graft with PCL/PU/gelatin co-electrospun and chitosan/silk fibroin/gelatin freeze-dried hydrogel for improved endothelialization and enhanced mechanical properties

Fabricating a biocompatible small-diameter vascular graft (< 6 mm) with mechanical properties similar to the natural vein and adding good anti-thrombogenic, endothelialization, and hyperplasia properties remains a challenge. To this end, we fabricated a heparinized bilayer graft to address this problem. The proposed bilayer sample consisted of a heparinized polycaprolactone (PCL), polyurethane (PU), and gelatin (G) co-electrospun inner layer and chitosan, gelatin, and silk fibroin freeze-dried hydrogel crosslinked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) outer layer. The samples exhibited great ultimate stress, Young's module, and suture retention of 4.16±0.25MPa, 8.24±2.59MPa and 4.83±0.31N, respectively. The heparin release assay indicated a sustained release profile of around 70% after 4weeks, which can be attributed to the excellent control via emulsion. Furthermore, the heparinized samples demonstrated good anti-thrombogenic properties investigated in the platelet adhesion assay. For the outer layer, the hydrogel crosslinked with non-toxic materials was prepared through the freeze-drying method to achieve high porosity (64.63%), suitable for smooth muscle cell activity. Moreover, inner and outer layers showed high cell viability toward endothelial (78.96%) and smooth muscle cells (57.77%), respectively. Overall, the proposed heparinized graft exhibited excellent potential for vascular graft regeneration.

Electrospun compliant heparinized elastic vascular graft for improving the patency after implantation

The low patency rate after artificial blood vessel replacement is mainly due to the ineffective use of anticoagulant factors and the mismatch of mechanical compliance after transplantation. Electrospun nanofibers with biomimetic extracellular matrix three-dimensional structure and tunable mechanical strength are excellent carriers for heparin. In this work, we have designed and synthesized a series of biodegradable poly(ester-ether-urethane)ureas (BEPU), following compound with optimized constant concentration of heparin by homogeneous emulsion blending, then spun into the hybrid BEPU/heparin nanofibers tubular graft for replacing rats' abdominal aorta in situ for comprehensive performance evaluation. The results in vitro demonstrated that the electrospun L-PEUUH (LDI-based PEUU with heparin) vascular graft was of regular microstructure, optimum surface wettability, matched mechanical properties, reliable cytocompatibility, and strongest endothelialization in situ. Replacement of resected abdominal artery with the L-PEUUH vascular graft in rat showed that the graft was capable of homogeneous hybrid heparin and significantly promoted the stabilization of vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs), as well as stabilizing the blood microenvironment. This research demonstrates the L-PEUUH vascular graft with substantial patency, indicating their potential for injured vascular healing.

Highly compliant biomimetic scaffolds for small diameter tissue-engineered vascular grafts (TEVGs) produced via melt electrowriting (MEW)

Biofabrication approaches toward the development of tissue-engineered vascular grafts (TEVGs) have been widely investigated. However, successful translation has been limited to large diameter applications, with small diameter grafts frequently failing due to poor mechanical performance, in particular mismatched radial compliance. Herein, melt electrowriting (MEW) of poly(ϵ-caprolactone) has enabled the manufacture of highly porous, biocompatible microfibre scaffolds with physiological anisotropic mechanical properties, as substrates for the biofabrication of small diameter TEVGs. Highly reproducible scaffolds with internal diameter of 4.0 mm were designed with 500 and 250µm pore sizes, demonstrating minimal deviation of less than 4% from the intended architecture, with consistent fibre diameter of 15 ± 2µm across groups. Scaffolds were designed with straight or sinusoidal circumferential microfibre architecture respectively, to investigate the influence of biomimetic fibre straightening on radial compliance. The results demonstrate that scaffolds with wave-like circumferential microfibre laydown patterns mimicking the architectural arrangement of collagen fibres in arteries, exhibit physiological compliance (12.9 ± 0.6% per 100 mmHg), while equivalent control geometries with straight fibres exhibit significantly reduced compliance (5.5 ± 0.1% per 100 mmHg). Further mechanical characterisation revealed the sinusoidal scaffolds designed with 250µm pores exhibited physiologically relevant burst pressures of 1078 ± 236 mmHg, compared to 631 ± 105 mmHg for corresponding 500µm controls. Similar trends were observed for strength and failure, indicating enhanced mechanical performance of scaffolds with reduced pore spacing. Preliminaryin vitroculture of human mesenchymal stem cells validated the MEW scaffolds as suitable substrates for cellular growth and proliferation, with high cell viability (>90%) and coverage (>85%), with subsequent seeding of vascular endothelial cells indicating successful attachment and preliminary endothelialisation of tissue-cultured constructs. These findings support further investigation into long-term tissue culture methodologies for enhanced production of vascular extracellular matrix components, toward the development of the next generation of small diameter TEVGs.

The Rate of Postoperative Complications in Complicated Acute, and Subacute Type B Aortic Dissections after TEVAR vs. PETTICOAT Procedures: Systematic Review and Meta-Analysis

Background and Objectives: Provisional extension to induce complete attachment (PETTICOAT) is suggested as being associated with a lower incidence of aorta-related events and fewer reinterventions compared to thoracic endovascular aortic repair (TEVAR) in patients with complicated acute, and subacute type B aortic dissections. Materials and Methods: This article is a systematic review and meta-analysis following the PRISMA guidelines. The Medline, PubMed, Embase, and Cochrane databases were searched, starting on 21 February 2022 and ending on 22 June 2022, to identify studies that investigated the rate of postoperative complications in patients treated with the PETTICOAT compared to the TEVAR. A random effects meta-analysis was performed. Of 2350 studies, 5 studies involving 360 patients were included: 143 patients after the PETTICOAT procedure and 217 after the TEVAR. Results: The meta-analysis of all studies showed that the rate of secondary endovascular reinterventions was smaller in patients treated with the PETTICOAT (n = 3 studies; OR, 0.30; 95% CI, 0.10 to 0.94; p = 0.04). The results of other postoperative complications (30-day mortality, mortality during follow-up, paraplegia, stroke, and occurrence of endoleak) were lower in the PETTICOAT group but were not statistically significant. The rate of postoperative renal failure was lower in patients treated with the TEVAR (n = 4; OR, 1.08; 95% CI, 0.46 to 2.51; p = 0.86). Conclusion: This meta-analysis suggests that the PETTICOAT procedure is related to the lower rate of secondary endovascular reinterventions for complicated acute, and subacute type B aortic dissections.

Bio-Bentall and hybrid arch frozen elephant trunk repair for acute type A aortic dissection with malperfusion

The extent of repair in patients with acute type A aortic dissection is often determined by factors such as entry tear location, aortic anatomy, malperfusion and team expertise. The hybrid arch frozen elephant trunk, which has become an established technique to extend the distal acute type A aortic dissection repair, is particularly useful in malperfusion; however, it remains technically challenging and is associated with increased duration of circulatory arrest and risks of spinal cord ischaemia. Proximal dissection flap extension often determines repairability versus replacement of the aortic root. We present a case report highlighting the proximal and distal extent of repair in a patient with a known ascending aortic aneurysm presenting with an acute type A aortic dissection, with malperfusion, undergoing a successful bio-Bentall procedure and hybrid arch frozen elephant trunk repair.

A hemodynamic analysis of fenestrated physician-modified endograft repair for complicated aortic dissections involving the visceral arteries

OBJECTIVE

The aim of this study is to perform patient-specific hemodynamic simulations of the patients with complicated aortic dissection underwent Physician-modified endograft (PMEG) and evaluate the treatment outcome.

METHOD

12 patient-specific models were reconstructed from computed tomography angiography (CTA) data of 6 patients with complicated aortic dissection before and after the PMEG. Hemodynamic simulations were conducted with the same time-varying volumetric flow rate extracted from the literature and 3-element Windkessel model (3 EWM) boundary conditions were applied at the aortic outlet. Hemodynamic indicators such as time-averaged wall shear stress (TAWSS), relative residence time (RRT) and endothelial cell activation potential (ECAP) were obtained to evaluate the postoperative effect of PMEG.

RESULTS

Comparing with the preoperative models, the flow rates of most visceral arteries were increased in the postoperative models (PSMA = 0.012, PRRA = 0.013, and PLRA = 0.005). Pressure and TAWSS in visceral regions were significantly reduced (PP = 0.003 and PTAWSS = 0.017). With the false lumens (FL) covered by the stent grafts, the average TAWSS level increased in the regions of postoperative abdominal aorta (P = 0.002), and the average RRT and ECAP values decreased significantly (PRRT = 0.02 and PECAP = 0.003).

CONCLUSION

This study shows that PMEG, as a new technique for the treatment of complicated aortic dissection involving the distal tears in the visceral region, can effectively restore the abnormal blood supply of the visceral arteries, reduce the risk of aortic rupture, the formation of aortic dissection aneurysm (ADA), and thrombosis. This corresponds well with clinical retrospective studies and 1-year follow-up outcomes. The findings of this study are of great significance for the development of PMEG.

Development, comparative structural analysis, and first in vivo evaluation of acellular implanted highly compacted fibrin tubes for arterial bypass grafting

The generation of small-caliber vascular grafts remains a significant challenge within the field of tissue engineering. In pursuit of this objective, fibrin has emerged as a promising scaffold material. However, its lack of biomechanical strength has limited its utility in the construction of tissue engineered vascular grafts. We have previously reported about the implementation of centrifugal casting molding to generate compacted fibrin tubes with a highly increased biomechanical strength. In this study, we conducted a structural analysis of compacted fibrin tubes using the open-source software Fiji/BoneJ. The primary aim was to validate the hypothesis that the compaction of fibrin leads to a more complex structure characterized by increased crosslinking of fibrin fibers. Structural analysis revealed a strong correlation between fibrin's structure and its biomechanical strength. Moreover, we enhanced fibrin compaction in a subsequent dehydration process, leading to a significant increase of biomechanical strength. Thus, the presented method in combination with an adequate imaging, e.g., micro-CT, has substantial potential as a powerful tool for quality assurance in the development of fibrin-based vascular grafts. To validate this concept, acellular highly compacted fibrin tubes were implanted as substitutes of a segment of the carotid artery in a sheep model (n = 4). After 6 months explanted segments exhibited distinct remodeling, transitioning into newly formed arteries.

Effectiveness of the Rotarex Excisional Atherectomy System in Both Subacute and Chronic Aortoiliac Endograft Thrombosis: An Innovative Option for the Modern Endovascular Surgeon Toolkit

PURPOSE

To report a successful revascularization case using the Rotarex™S atherothrombectomy system in a recent iliac limb thrombosis, and chronic hypogastric stent obstruction after previous aortoiliac aneurysm endovascular repair (EVAR).

CASE REPORT

A 72-year-old patient was treated for recent right iliac limb thrombosis and left iliac branch chronic hypogastric stent occlusion, 5 years after EVAR. A total endovascular approach, using both upper extremity and femoral vascular access, was settled with 2 Rotarex™S (6Fr and 10Fr) devices. The Rotarex™S catheters removed most of the intraluminal material, allowing additional endografts and bare metal stents to be deployed to support a new healthy lumen surface.

CONCLUSION

The total endovascular approach provided by the Rotarex™S device appears to be safe and effective in treating aortoiliac endografts occlusions, both in subacute and chronic phases. Larger studies could highlight differences and eventual advantages compared with more traditional solutions.

Frozen elephant trunk technique for aortic arch surgery: the Bordeaux University Hospital experience with Thoraflex hybrid prosthesis

BACKGROUND

Aortic arch surgery still represents a challenge, and the frozen elephant trunk (FET) allows a one-step surgery for complex aortic diseases. The aim of the study was to analyze the results of patients undergoing FET procedure for aortic arch surgery at Bordeaux University Hospital.

METHODS

Patients undergoing FET procedure for multisegmented aortic arch pathologies were analyzed in this single-center retrospective study. Further subgroup analyses were performed according to the degree of urgency of the operation (elective versus emergent surgery) and cerebral protection technique: bilateral selective antegrade cerebral perfusion (B-SACP) versus the unilateral one (U-SACP), regardless of the degree of urgency.

RESULTS

From August 2018 to August 2022, 77 consecutive patients (64.1±9.9 years, 54 males) were enrolled: 43 (55.8%) for elective surgery and 34 (44.2%) in emergency. Technical success was 100%. 30-day mortality was 15.6% (N.=12, 7% elective vs. 26.5% emergent, P=0.043). Six (7.8%) non-disabling strokes occurred (1.9% B-SACP vs. 20% U-SACP, P=0.021). Median follow-up was 1.11 years (interquartile range, 0.62-2.07). The 1-year overall survival was 81.6±4.45%. The elective group showed a survival trend when compared to the emergency one (P=0.054). However, further examination at landmark analysis elective surgery showed a better survival trend compared to emergency surgery up to 1.78 years (P=0.034), after which significance was lost (P=0.521).

CONCLUSIONS

Thoraflex hybrid prosthesis for FET technique demonstrated feasibility and satisfactory short-term clinical outcomes, even in emergent settings. In our practice B-SACP seems to offer better protection and less neurological complications compared to U-SACP, nevertheless further analyses are warranted.