Deep Learning-Based Intraoperative Stent Graft Segmentation on Completion Digital Subtraction Angiography During Endovascular Aneurysm Repair

PURPOSE

Modern endovascular hybrid operating rooms generate large amounts of medical images during a procedure, which are currently mostly assessed by eye. In this paper, we present fully automatic segmentation of the stent graft on the completion digital subtraction angiography during endovascular aneurysm repair, utilizing a deep learning network.

TECHNIQUE

Completion digital subtraction angiographies (cDSAs) of 47 patients treated for an infrarenal aortic aneurysm using EVAR were collected retrospectively. A two-dimensional convolutional neural network (CNN) with a U-Net architecture was trained for segmentation of the stent graft from the completion angiographies. The cross-validation resulted in an average Dice similarity score of 0.957 ± 0.041 and median of 0.968 (IQR: 0.950 - 0.976). The mean and median of the average surface distance are 1.266 ± 1.506 mm and 0.870 mm (IQR: 0.490 - 1.430), respectively.

CONCLUSION

We developed a fully automatic stent graft segmentation method based on the completion digital subtraction angiography during EVAR, utilizing a deep learning network. This can provide the platform for the development of intraoperative analytical applications in the endovascular hybrid operating room such as stent graft deployment accuracy, endoleak visualization, and image fusion correction.

Outcomes of Omniflow® II prosthesis used for revascularization in the femoral tract both in infected and non-infected setting

BACKGROUND

Evidence regarding the outcomes of Omniflow® II prosthesis in peripheral arterial revascularization at different anatomical sites and for different indications is scarce. Therefore, the aim of this study was to evaluate the outcomes of the Omniflow® II used at various positions within the femoral tract both in infected and non-infected setting.

METHODS

Patients who underwent reconstructive lower leg vascular surgery with implantation of an Omniflow® II from 2014 until 2021 at five medical centers were retrospectively included (N.=142). Patients were subdivided into the following categories: femoro-femoral crossover (N.=19), femoral interposition (N.=18), femoro-popliteal (above-the-knee [N.=25; AK] or below-the-knee [N.=47; BK]), and femoro-crural bypass grafts (N.=33). Primary outcome was primary patency and secondary outcomes included primary assisted patency, secondary patency, major amputation, vascular graft infection, and mortality. Outcomes were compared according to different subgroups and the surgical setting (infected versus non-infected).

RESULTS

The median follow-up was 35.0 (17.5-54.3) months. Three years primary patency of 58% was observed for femoro-femoral crossover bypass, 75% for femoral interposition graft, 44% for femoro-popliteal above-the-knee bypass, 42% for femoro-popliteal below-the-knee bypass, and 27% in the femoro-crural position (P=0.006). Freedom from major amputation at three years were 84% for femoro-femoral crossover bypass, 88% for femoral interposition bypass, 90% for femoro-popliteal AK bypass, 83% for femoro-popliteal BK bypass, and 50% for femoro-crural bypass (P<0.001).

CONCLUSIONS

This study demonstrates the safety and feasibility of the use of Omniflow® II for femoro-femoral crossover-, femoral interposition-, and femoro-popliteal (AK and BK) bypass. Omniflow® II seems to be less suitable for femoro-crural bypass with a significantly lower patency compared to other positions.

Multicenter Comparison of Aortic Arch Aneurysms and Dissections Zone 0 Hybrid and Total Endovascular Repair

PURPOSE

Comparison of hybrid and total endovascular aortic arch repair at two tertiary vascular surgery centers.

MATERIALS AND METHODS

Consecutive patients undergoing hybrid (HG) or total endovascular (TEG) total aortic arch repair for aneurysms or dissections were included (2008-2022). Primary outcome measure was 30-day mortality. Secondary outcomes were major complications, technical success (defined as absence of surgical conversion/mortality, high-flow endoleaks or branch/limb occlusion), clinical success (defined as absence of disabling clinical sequelae), late and aortic-related mortality/reinterventions, freedom from endoleaks, aortic diameter growth > 5 mm, graft migration and supra-aortic trunks (SAT) patency.

RESULTS

In total, 30 patients were included, 17 in HG and 13 in TEG. TEG presented shorter intervention time (240.5 vs 341 min, p = 0.01), median ICU stay (1 vs 4.5 days, p < 0.01) and median length of stay (8 vs 17.5 days, p < 0.01). No intraoperative deaths occurred. Technical success was 100%; clinical success was 70.6% in HG and 100% in TEG (p = 0.05). Thirty-day mortality was 13.3%, exclusively in HG (p = 0.11). Nine major complications occurred in 8 patients, 5 in HG and 3 in TEG (p = 0.99), among which five strokes, two in HG and three in TEG (p = 0.62). Late mortality was 38.5%, six patients in HG and four in TEG, p = 0.6. Two late aortic-related deaths occurred in HG (p = 0.9). Two aortic-related reinterventions, no graft migration or SAT occlusion was observed.

CONCLUSIONS

Total endovascular repair seems to shorten operative times and provide higher clinical success compared with hybrid solutions, without significant 30-day mortality differences. The most common major complication is stroke.

Self-occluding Candy-Plug: Implantation Technique to Obtain False Lumen Thrombosis in Chronic Aortic Dissections

PURPOSE

To describe the implantation steps of the latest generation of candy-plug device (third CP generation [CP III]) and to illustrate its possible pitfalls by discussing a case in whom this device was employed to occlude the false lumen (FL) of a chronic type B aortic dissection.

TECHNIQUE

A 69 year-old male patient who underwent a frozen elephant trunk arch repair due to residual type A aortic dissection developed a FL aneurysmal degeneration limited to the descending thoracic aorta. Two thoracic stent-grafts were deployed into the true lumen up to the celiac trunk origin. Then, the FL was occluded with a self-occluding CP III device (Cook Medical, Bloomington, Indiana), placed at the same level as the distal thoracic stent-graft. The distal un-stented sleeve was pushed upward to allow immediate occlusion of its central lumen, avoiding interference with reno-visceral arteries arising from the FL. Both intraoperative transesophageal echocardiography and follow-up computed tomographic angiography scan demonstrated complete FL thrombosis.

CONCLUSION

The introduction of CP III with its self-occluding mechanism helped to shorten and standardize the procedure. However, adjunctive steps may be needed to immediately obtain FL occlusion and avoid hampering the perfusion of vessels arising from the FL.

Endovascular maneuvers for contralateral stent graft limb misplacement in endovascular aortic repair

Cannulation and placement of the contralateral stent graft limb during endovascular aortic repair (EVAR) procedure are crucial steps as mispositioning may lead to conversion to open aortic repair. Endovascular bail-out strategies for stent graft relocation in EVAR are underreported though detailed knowledge may facilitate application and prevent conversion. We present three endovascular bail-out strategies for repositioning of a mispositioned contralateral stent graft limb. (1) Retraction of the mispositioned component with an inflated reliant balloon and placement of an interposition stent graft after successful cannulation; (2) Push-maneuver of the mispositioned stent graft into the infrarenal aortic aneurysm with an inflated reliant balloon supported by a large lumen introducer sheath and (3) Parallel placement of a second contralateral stent graft limb displacing the mispositioned one against the atrial wall in cases with adequate vessel diameter. Prevention of stent graft mispositioning by applying recognized tests to ensure correct placement are essential, following the slogan: check twice, deploy once.

Novel repair of acute Stanford type B aortic dissection using combined endovascular graft and transfemoral replacement of vascular plug

We present successful treatment of dissected thoracoabdominal aorta using combined thoracic endovascular aortic repair and transfemoral replacement of Amplatzer™ vascular plug in a 38-year-old patient. Computed tomography angiography revealed a false lumen from the left subclavian artery to the left common iliac trunk, with re-entries connecting it to the true lumen of the aorta. We replaced the prosthetic endovascular graft just below the left subclavian artery to the top of the superior mesenteric artery. Amplatzer™ vascular plug was replaced below the diaphragm in a closed transfemoral procedure to prevent re-entry. The patient was discharged in good condition and 2 years postoperation imaging showed complete pseudoaneurysm closure.

Thoracic Stent Graft Numerical Models To Virtually Simulate Thoracic Endovascular Aortic Repair: A Scoping Review

OBJECTIVE

Pre-procedural planning of thoracic endovascular aortic repair (TEVAR) may implement computational adjuncts to predict technical and clinical outcomes. The aim of this scoping review was to explore the currently available TEVAR procedure and stent graft modelling options.

DATA SOURCES

PubMed (MEDLINE), Scopus, and Web of Science were systematically searched (English language, up to 9 December 2022) for studies presenting a virtual thoracic stent graft model or TEVAR simulation.

REVIEW METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) was followed. Qualitative and quantitative data were extracted, compared, grouped, and described. Quality assessment was performed using a 16 item rating rubric.

RESULTS

Fourteen studies were included. Among the currently available in silico simulations of TEVAR, severe heterogeneity exists in study characteristics, methodological details, and evaluated outcomes. Ten studies (71.4%) were published during the last five years. Eleven studies (78.6%) included heterogeneous clinical data to reconstruct patient specific aortic anatomy and disease (e.g., type B aortic dissection, thoracic aortic aneurysm) from computed tomography angiography imaging. Three studies (21.4%) constructed idealised aortic models with literature input. The applied numerical methods consisted of computational fluid dynamics analysing aortic haemodynamics in three studies (21.4%) and finite element analysis analysing structural mechanics in the others (78.6%), including or excluding aortic wall mechanical properties. The thoracic stent graft was modelled as two separate components (e.g., graft, nitinol) in 10 studies (71.4%), as a one component homogenised approximation (n = 3, 21.4%), or including nitinol rings only (n = 1, 7.1%). Other simulation components included the catheter for virtual TEVAR deployment and numerous outcomes (e.g., Von Mises stresses, stent graft apposition, drag forces) were evaluated.

CONCLUSION

This scoping review identified 14 severely heterogeneous TEVAR simulation models, mostly of intermediate quality. The review concludes there is a need for continuous collaborative efforts to improve the homogeneity, credibility, and reliability of TEVAR simulations.

[Efficacy of Distal Perfusion During Frozen Elephant Trunk Procedure:Continuous Perfusion Versus Intermittent Perfusion]

PURPOSE

To compare the effectiveness of continuous distal perfusion( CDP) with that of intermittent distal perfusion( IDP) during frozen elephant trunk( FET) procedures.

METHODS

There were 54 patients in the CDP group and 15 patients in the IDP group. There were no significant differences in preoperative characteristics between the two groups, but dissection was more common in the IDP group than in the CDP group, and the maximum aneurysmal diameter was larger in the CDP group than in the IDP group.

RESULTS

Emergency surgery was significantly more common in the IDP group than in the CDP group. Operating time, cardiopulmonary bypass time, lower body arrest time, and aortic cross-clamp time were significantly longer in the IDP group. Postoperative paraparesis occurred in one case in each group, and temporary paraparesis occurred in two cases in the CDP group, with no significant differences, including in mechanical ventilation time. There were two in-hospital deaths, one due to respiratory failure and one due to ischemic colitis, in the CDP group and one due to multiple organ failure in the IDP group. Postoperative liver and renal functions did not differ significantly between the two groups.

CONCLUSION

IDP has proven to be almost as effective as CDP during FET for preventing spinal cord ischemia and maintaining respiratory, liver, and renal functions.

Implantation of ascyrus medical dissection stent, our first-hand experience

BACKGROUND

Acute type A aortic dissection is associated with high perioperative morbidity and mortality. Ascyrus Medical Dissection Stent (Cryolife, Kennesaw, USA) is a novel uncovered hybrid stent graft developed to be used as an adjunct to standard surgical approach to promote true lumen expansion and enhance aortic remodeling.

METHODS

From March 2021 to March 2022, four consecutive patients presented with acute Debakey type I aortic dissection and underwent emergent surgical repair with Tirone David procedure and implantation of Ascyrus Medical Dissection Stent. We reviewed patient's files retrospectively and described the perioperative outcomes.

RESULTS

All four device implantations were successful. Overall 30-day mortality was 0%. Malperfusion that was present in two patients pre-operatively improved after Ascyrus Medical Dissection Stent implantation. No aortic reinterventions were needed. No aortic injury related to the device was noted. Favourable changes in aortic true lumen and false lumen dimensions were found in most of our patients but the stent was compressed at the isthmus in one patient.

CONCLUSION

Ascyrus Medical Dissection Stent is a reliable and secure device. However, its benefits remain unclear when it comes to a positive remodeling and seems less likelihood comparable to a frozen elephant trunk. The main reason seems to be an insufficient radial force of the stent.

Treatment with a flow diverter-assisted coil embolization for ruptured blood blister-like aneurysms of the internal carotid artery: a technical note and analysis of single-center experience with pooled data

Treatment of blood blister-like aneurysms (BBAs) of the supraclinoid internal carotid artery (ICA) with flow diverters (FDs) has become widespread in recent years. However, ruptured blood blister-like aneurysm (BBA) of ICA treatment with flow diverter-assisted coil embolization (FDAC) remains controversial. Moreover, limited direct comparative studies have been conducted between the two treatment modalities, FDs and FDAC, for BBAs. The purpose of this study was to document our experience and evaluate the effectiveness and safety of FDAC. We conducted a retrospective analysis of clinical and radiological information from ten patients who experienced ruptured BBAs of the supraclinoid ICA at our center from January 2021 to February 2023. The technical details of FDAC for ruptured BBAs were described, and the technical steps were named "pipeline embolization device (PED)-Individualized shaping(microcatheter)-Semi deploying-Rivet(coils)-Massage(microwire)" as the PEISSERM technique. Clinical outcomes were assessed using the modified Rankin Scale (mRS), whereas radiological results were determined through angiography. A pooled analysis was implemented, incorporating data from literature sources that reported perioperative and long-term clinical and angiographic outcomes of ruptured BBAs treated with FD and FDAC strategies, along with our data. Data in our analysis pool were categorized into FD and FDAC strategy groups to explore the preferred treatment modalities for BBAs. The PEISSERM technique was utilized to treat ten patients, seven males, and three females, with an average age of 41.7 years. A single PED was deployed in conjunction with coils in all ten patients. All PEDs were documented to have good wall apposition. The immediate postoperative angiograms demonstrated Raymond grade I in ten aneurysms. Angiographic follow-up of nine patients at 4-25 months showed total occlusion of the aneurysms. At the most recent follow-up, the mRS scores of nine patients hinted at a good prognosis. Pooled analysis of 233 ICA-BBA cases of FD revealed a technical success rate of 91% [95% confidence interval (CI), 0.88 to 0.95], a rate of complete occlusion of 79% (95% CI, 0.73 to 0.84), a recurrence rate of 2% (95% CI, 0.00 to 0.04), a rebleed rate of 2% (95% CI, 0.00 to 0.04), and the perioperative stroke rate was 8% (95% CI, 0.04 to 0.11). The perioperative mortality was 4% (95% CI, 0.01 to 0.07). The long-term good clinical outcome rate was 85% (95% CI, 0.80 to 0.90). The mortality rate was 6% (95% CI, 0.03 to 0.09). Results from the subgroup analysis illustrated that the FDAC strategy for BBAs had a significantly higher immediate postoperative complete occlusion rate (P < 0.001), total occlusion rate (P = 0.016), and a good outcome rate (P = 0.041) compared with the FD strategy. The FDAC strategy can yield a higher rate of good outcomes than the FD strategy. The PEISSERM technique employed by the FDAC is a reliable and effective treatment approach as it can minimize the hemodynamic burden of BBA's fragile dome, thereby achieving an excellent occlusion rate. The PEISSERM technique in the FDAC strategy contributes to understanding the BBA's treatment and offers a potentially optimal treatment for BBA.

Endovascular treatment of chronic mesenteric ischaemia secondary to a superior mesenteric artery pseudoaneurysm: a modified neurointerventional technique

A man in his late 60s presented with intermittent abdominal pain, nausea, vomiting and approximately 40 pounds of weight loss over the course of a year, most concerning for chronic mesenteric ischaemia. Given a prior negative workup, a CT angiogram was performed and revealed a wide neck mid-superior mesenteric artery pseudoaneurysm (PSA). As PSAs are susceptible to thrombus formation and distal emboli, this incidental finding was considered a possible explanation for his intermittent symptoms and thus required treatment. Anatomical constraints precluded traditional coiling or covered stent placement, so the interventional radiology team used a neurointerventional technique and performed a successful balloon-assisted coil embolisation of the PSA with subsequent resolution of the patient's symptoms. More than 3 years postprocedure, the patient remains asymptomatic with no complications.

Surgical bypass to the left subclavian artery: an extra-anatomical transpleural approach

A distal anastomosis in zone 3 is technically demanding during the frozen elephant trunk procedure. Proximalization of the distal anastomosis to zone 2 with subsequent revascularization of the left subclavian artery is an attractive alternative. This video tutorial describes the technique of an extra-anatomical bypass from the aortic prosthesis to the infraclavicular left subclavian (axillary) artery in arch replacement with the distal aortic graft anastomosis in zone 2.

Double-Barrel Technique With Reversed Gore Excluder Stent Graft Limb for Common Iliac Aneurysm Exclusion in a Patient With Prior Aortic Surgical Repair

Surgical repair of a common iliac artery aneurysm (CIA) after previous open aortic reconstruction is associated with significant morbidity and mortality. Endovascular repair is considered less invasive than surgery. However, if preservation of the internal iliac artery (IIA) is required, the applicability of endovascular techniques may represent a challenge and a limitation to the use of standard aortic endografts or iliac branch devices. In these cases, the off-label use of endovascular devices may be an effective alternative. Herein, we report a successful hybrid approach to treat CIA using a reversed iliac limb endograft coupled with a double-barrel technique with femoro-femoral crossover bypass in a patient who had previously undergone open aortic reconstruction.

Translational tissue-engineered vascular grafts: From bench to bedside

Cardiovascular disease is a primary cause of mortality worldwide, and patients often require bypass surgery that utilizes autologous vessels as conduits. However, the limited availability of suitable vessels and the risk of failure and complications have driven the need for alternative solutions. Tissue-engineered vascular grafts (TEVGs) offer a promising solution to these challenges. TEVGs are artificial vascular grafts made of biomaterials and/or vascular cells that can mimic the structure and function of natural blood vessels. The ideal TEVG should possess biocompatibility, biomechanical mechanical properties, and durability for long-term success in vivo. Achieving these characteristics requires a multi-disciplinary approach involving material science, engineering, biology, and clinical translation. Recent advancements in scaffold fabrication have led to the development of TEVGs with improved functional and biomechanical properties. Innovative techniques such as electrospinning, 3D bioprinting, and multi-part microfluidic channel systems have allowed the creation of intricate and customized tubular scaffolds. Nevertheless, multiple obstacles must be overcome to apply these innovations effectively in clinical practice, including the need for standardized preclinical models and cost-effective and scalable manufacturing methods. This review highlights the fundamental approaches required to successfully fabricate functional vascular grafts and the necessary translational methodologies to advance their use in clinical practice.

Association Between Conduit Type and Outcomes After Open Repair of Popliteal Artery Aneurysms

INTRODUCTION

Prior studies have demonstrated acceptable midterm outcomes with prosthetic conduits for above-knee bypass for occlusive disease in patients with inadequate segment great saphenous vein (GSV). In this study we aimed to investigate whether this holds true for open repair of popliteal artery aneurysms (PAA).

METHODS

We queried the Vascular Quality Initiative data for patients who underwent open PAA repair (OPAR). We divided the cohort into three groups based on the conduit used: GSV, other autologous veins, or prosthetic graft. Study outcomes included primary patency, freedom from major amputation, amputation-free survival, and overall survival at 1 y. Kaplan-Meier survival estimates, log-rank tests and multivariable Cox regression were used to compare outcomes between study groups.

RESULTS

A total of 4016 patients underwent bypass for PAA from January 2010 to October 2021. The three cohorts were significantly different in many demographic and clinical characteristics. The adjusted odds of postoperative amputation among symptomatic patients were 3-fold higher for prosthetic conduits compared to the GSV (odds ratio, 3.20; 95% CI, 1.72-5.92; P < 0.001). For the 1-y outcomes, the adjusted risk of major amputation was almost 3-fold higher for patients with symptomatic disease undergoing bypass with prosthetic conduits (hazard ratio [HR], 2.97; 95% CI, 1.35-6.52; P = 0.007). When compared with GSV, prosthetic conduits were associated with 96% increased risk of death when used for repair in symptomatic patients (adjusted hazard ratio (aHR), 1.96; 95% CI, 1.29-2.97; P = 0.002) but no significant association with mortality in asymptomatic patients (aHR, 0.83; 95% CI, 0.37-1.87; P = 0.652). When compared with GSV, prosthetic conduits were associated with a 2-fold increased risk of 1-y major amputation or death when used for repair in symptomatic patients (aHR, 2.03; 95% CI, 1.40-2.94; P < 0.001) but no significant association with mortality in asymptomatic patients (aHR, 0.91; 95% CI, 0.42-1.98; P = 0.816). Comparing bypass with other veins to the GSV among patients with symptomatic disease, there was no statistically significant difference in major amputation risk (HR; 2.44; 95% CI, 0.55-10.82; P = 0.242) and no difference in the adjusted risk of all-cause mortality (aHR, 0.77; 95% CI, 0.26-2.44; P = 0.653). There were no differences in the adjusted risk of loss of primary patency comparing other veins to GSV (HR, 1.53; 95% CI, 0.85-2.76; P = 0.154) and prosthetic conduits to GSV (HR, 0.85; 95% CI, 0.57-1.26; P = 0.422).

CONCLUSIONS

This large study shows that among patients undergoing OPAR, 1-y primary patency does not differ between conduit types. However, prosthetic conduits are associated with significantly higher risk of amputation and death compared to GSV among symptomatic patients. Though non-GSV autologous veins are less often used for OPAR, they have comparably acceptable outcomes as GSV.

Clinical Study on the Management of Aortic Dissection Involving the Aortic Arch through Endovascular Isolation and In Situ Fenestration with Covered Stent

Objective

This study aimed to investigate the clinical effectiveness of the SilverFlow branch stent through endovascular isolation and in situ fenestration (ISF) for the treatment of aortic dissection (AD) involving the aortic arch.

Methods

A total of 21 patients with AD involving the aortic arch, admitted to our hospital between September 2021 and January 2023, were selected for this prospective study. All patients underwent treatment with an endoluminal isolated ISF-covered stent, with the branch stent being the SilverFlow, developed by Shenzhen Xianjian Company. We assessed the success rate of the ISF procedure stent-related complications and compared the volumes of the true and false cavities before and after treatment. Follow-up evaluations were conducted 1, 3, and 6 months post-operation, focusing on neurological complications, mortality, and the need for secondary interventional treatment.

Results

Among the 21 AD patients with aortic arch involvement, 20 (95.23%) underwent non-emergency surgery, while 1 (4.76%) required emergency surgery due to cardiac ischemia and signs of dissection rupture. All surgeries were successfully completed. After treatment, the average volume of the true lumen significantly decreased compared to pre-treatment levels, while the volume of the false lumen significantly increased (P < .05). The success rate was 100%, with only one case (4.76%) experiencing type I internal leakage. There were no cases of stent displacement, distortion, or fenestration vessel occlusion. One patient (4.76%) succumbed to acute pericardial tamponade, resulting in a mortality rate of 4.76%. Another patient (4.76%) suffered from upper limb ischemia, significantly improving with antithrombotic drug treatment. No occurrences of stroke, visceral ischemia, or other complications were reported, and no secondary interventional treatments were required.

Conclusions

The application of the SilverFlow branch stent for endovascular isolation of ISF in AD cases involving the aortic arch demonstrates a high success rate, low complication and mortality rates, and significant clinical feasibility and value.

Abdominal Penetrating Aortic Ulcer and Endovascular Treatments: A Systematic Review and Meta-Analysis

BACKGROUND

Abdominal penetrating aortic ulcer (aPAU) is defined as an ulceration of the aortic intima and media lamina, even with rupture of the internal elastic lamina. Recently, there have been an increasing number of publications on endovascular treatment for aPAU. This review aimed to assess the efficacy and safety of endovascular treatment and provide clinicians with the latest evidence-based medical data.

METHODS

3 academic databases (Embase, PubMed, and Scopus) were systematically searched for literature reporting on aPAU from 1986 (the earliest appearance of the concept of aPAU) to September 1, 2021, and related data were collected and evaluated. A fixed/random effects model was used to construct the forest plots. Funnel plots and linear regression tests were used to assess the publication bias.

RESULTS

6 articles including 121 patients were included in the analysis. The average age was 71.4 years, with 72.7% of males and 85.6% with hypertension. Saccular aneurysms (SA) were the most prevalent complication (35.5%). Endovascular treatment had a perioperative mortality rate of .24% (95% CI, .00-2.70). The technical success rate was 99.15% (95% CI, 96.49-100). The type-II endoleak rate was 5.69% (95% CI, .00-12.13). The 1-year survival rate was 95.69% (95% CI, 90.49-100). The revascularization rate was 7.20% (95% CI, .07-14.32). Endovascular treatments for aPAU would lead to a high rate of technical success, few complications, and satisfactory 1-year survival.

CONCLUSIONS

aPAU are a common disease that mainly affects elderly males with hypertension and hyperlipidemia. Endovascular treatment is required when an ulcer progresses rapidly or manifests symptoms. Endovascular treatment is associated with high technical success, low complication, and satisfactory 1-year survival. Further investigation into the long-term results of endovascular treatment is necessary.

Thoracic Endovascular Aortic RepairAcutely Augments Left Ventricular Biomechanics in An Animal Model: A Mechanism for Postoperative Heart Failure and Hypertension

BACKGROUND

Thoracic aortic stent grafts are thought to decrease aortic compliance and may contribute to hypertension and heart failure after thoracic endovascular aortic repair (TEVAR). Left ventricular (LV) biomechanics immediately after TEVAR, however, have not been quantified. Pressure-volume (PV) loop analysis provides gold-standard LV functional information. The aim of this study is to use an LV PV loop catheter and analysis to characterize the LV biomechanics before and acutely after TEVAR.

METHODS

Anesthetized Yorkshire swine (N = 6) were percutaneously instrumented with an LV PV loop catheter. A 20 mm × 10 cm stent graft was deployed distal to the left subclavian via the femoral artery under fluoroscopy. Cardiac biomechanics were assessed before and after TEVAR. As a sensitivity analysis, inferior vena cava occlusion with PV loop assessment was performed pre and post-TEVAR in 1 animal to obtain preload and afterload-independent end-systolic and end-diastolic PV relationships (ESPVR and EDPVR).

RESULTS

All animals underwent successful instrumentation and TEVAR. Post-TEVAR, all 6 animals had higher mean LV ESP (106 vs. 118 mm Hg, P = 0.04), with no change in the EDPVR. inferior vena cava occlusion also moved the ESPVR curve upward and leftward, indicating increased LV work per unit time. There was no augmentation of EDPVR following TEVAR (P > 0.05). Postmortem exams in all animals revealed appropriate stent placement and no technical complications.

CONCLUSIONS

TEVAR was associated with an acute increase in LV end-systolic pressure and shift in the ESPVR, indicating increased ventricular work. This data provides potential mechanistic insights into the development of post-TEVAR hypertension and heart failure. Future stent graft innovation should focus on minimizing the changes in cardiac physiology.

Hydrostatic pressure under hypoxia facilitates fabrication of tissue-engineered vascular grafts derived from human vascular smooth muscle cells in vitro

Biologically compatible vascular grafts are urgently required. The scaffoldless multi-layered vascular wall is considered to offer theoretical advantages, such as facilitating cells to form cell-cell and cell-matrix junctions and natural extracellular matrix networks. Simple methods are desired for fabricating physiological scaffoldless tissue-engineered vascular grafts. Here, we showed that periodic hydrostatic pressurization under hypoxia (HP/HYP) facilitated the fabrication of multi-layered tunica media entirely from human vascular smooth muscle cells. Compared with normoxic atmospheric pressure, HP/HYP increased expression of N-myc downstream-regulated 1 (NDRG1) and the collagen-cross-linking enzyme lysyl oxidase in human umbilical artery smooth muscle cells. HP/HYP increased N-cadherin-mediated cell-cell adhesion via NDRG1, cell-matrix interaction (i.e., clustering of integrin α5β1 and fibronectin), and collagen fibrils. We then fabricated vascular grafts using HP/HYP during repeated cell seeding and obtained 10-layered smooth muscle grafts with tensile rupture strength of 0.218-0.396 MPa within 5 weeks. Implanted grafts into the rat aorta were endothelialized after 1 week and patent after 5 months, at which time most implanted cells had been replaced by recipient-derived cells. These results suggest that HP/HYP enables fabrication of scaffoldless human vascular mimetics that have a spatial arrangement of cells and matrices, providing potential clinical applications for cardiovascular diseases. STATEMENT OF SIGNIFICANCE: Tissue-engineered vascular grafts (TEVGs) are theoretically more biocompatible than prosthetic materials in terms of mechanical properties and recipient cell-mediated tissue reconstruction. Although some promising results have been shown, TEVG fabrication processes are complex, and the ideal method is still desired. We focused on the environment in which the vessels develop in utero and found that mechanical loading combined with hypoxia facilitated formation of cell-cell and cell-matrix junctions and natural extracellular matrix networks in vitro, which resulted in the fabrication of multi-layered tunica media entirely from human umbilical artery smooth muscle cells. These scaffoldless TEVGs, produced using a simple process, were implantable and have potential clinical applications for cardiovascular diseases.

Structural numerical analysis of a branched modular stent-graft for aneurysms encompassing all zones of the aortic arch

The development of stent-grafts for the total repair of aneurysms in the aortic arch is still a technical challenge due mainly to the anatomical complexity of this region. Research performed here structurally evaluated a modular branched stent-graft for aneurysms encompassing all zones of the aortic arch by means of numerical simulations using fluid-structure interaction. The geometric domain obtained by means of computed tomography was subjected to physiological boundary conditions. The blood was modelled as non-Newtonian by the Carreau model, and the arterial wall was modelled as anisotropic hyperelastic by the Holzapfel model. The material adopted for the stents was Nitinol, and expanded polytetrafluoroethylene (ePTFE) was used for the graft. A comparison of the structural behaviour of the aneurysmal aortic arch before and after stent-graft implantation was performed. The numerical flow model was experimentally verified in vitro on a representative test bench of blood flow in the aortic arch. The stent-graft was shown to minimally modify arterial wall dynamics and was not susceptible to migration and endoleak. Peak stresses and strains were found in the stents and graft, respectively, while the stresses in the aneurysm sac were significantly reduced, of the order of 97.5%, due to the isolation of the arterial wall by the stent-graft.

Hemodynamics of different configurations of the left subclavian artery parallel stent graft for thoracic endovascular aortic repair

BACKGROUND AND OBJECTIVE

Parallel (chimney and periscope) graft technique is an effective approach for left subclavian artery (LSA) reconstruction in patients treated by thoracic endovascular aortic repair (TEVAR) for the inadequate landing zone. However, certain stent graft (SG) configurations may promote thrombosis and reduce distal blood flow, increasing risks of cerebral infarction and reintervention.

METHODS

In this paper, we first attempt to systematically evaluate the hemodynamic performances of different parallel graft techniques as potential determinants of complication risks. Based on the patient-specific 3D aortic geometry undergoing parallel graft technique, fifteen models in total for five kinds of LSA branched SG configurations (Forward, Backward, Extended, Elliptical and Periscopic) were designed virtually, and the hemodynamic discrepancies between them were analyzed by computational fluid dynamics.

RESULTS

Results show that flow rate of patients undergoing periscope technique reduces by half compared with chimney technique, suggesting that periscope SG may cause more serious flow obstruction to LSA, leading to stroke. For chimney stent structure, the extension length 0has little influence on energy loss and other parameters. Conversely, hemodynamic differences between the retrograde curvature and the antegrade curvature are significant (time average WSS: 47.07%), so the retrograde curvature might prompt SG displacement. Furthermore, the flatter chimney SG induces more aggressive hemodynamic forces, among which the difference of the maximum WSS between the flatter SG and nearly round SG reaches 65.56%, leading to the greater risk of vascular wall damage.

CONCLUSIONS

Results obtained might provide suggestions for physicians to formulate appropriate parallel graft technique schemes in TEVAR.

Cryopreserved Arterial Allografts Versus Rifampin-Soaked Dacron for the Treatment of Infected Aortic and Iliac Aneurysms

BACKGROUND

Infected aortic and iliac artery aneurysms are challenging to treat. Cryopreserved arterial allografts (CAAs) or rifampin-soaked Dacron (RSD) are standard options for in situ reconstruction. Our aim was to compare the safety and effectiveness of CAA versus RSD for these complex pathologies.

METHODS

This is a retrospective review of infected iliac, abdominal, and thoracoabdominal aortic aneurysms treated with either CAAs or RSD between 2002 and 2022 at our institution. The diagnosis was confirmed by intraoperative, radiologic, or microbiological evidence of aortic infection. Perioperative events, 30-day and long-term mortality, reinfection, and reintervention were analyzed.

RESULTS

Thirty patients (17 CAA, 13 RSD) with a mean age of 61 and 68 years, respectively, were identified. The infected aneurysm was most commonly suprarenal or infrarenal. Culture-negative infections were present in 47% of the CAA group and 54% in the RSD group. Early major morbidity was 57% and 54% for the CAA and RSD, respectively. Thirty-day mortality was similar between groups (18% vs. 23% CAA vs. RSD, P ≥ 0.99). Median follow-up was longer in the RSD group (14.5 months vs. 13 months). Overall survival at 1 and 5 years was 80.8% and 64.8% in the CAA group and 69.2% and 57.7% in the RSD group. Reinterventions only occurred with CAA repairs and indications included graft occlusion (2), multiple pseudoaneurysms and reinfection (1), and hemorrhagic shock caused by graft rupture (1). Freedom from reintervention at 1 and 3 years was 87.5% and 79.5% (CAA group) versus 100% and 100% (RSD, P = 0.06). Freedom from reinfection at 1 year was 100% in both groups, while at 3 years it was 90.9% for the CAA group and 100% for the RSD group (P = 0.39).

CONCLUSIONS

Infected aortic and iliac aneurysms have high early morbidity and mortality. CAA and RSD had similar outcomes in our series; CAA trended toward higher reintervention rates. Both remain viable options for complex scenarios but require close surveillance.

Zone 0 TEVAR with femoral artery inflow for an anastomotic pseudoaneurysm

We describe the case of an 89-year-old female with a distal anastomotic pseudoaneurysm of the ascending aorta after an ascending aorta replacement for an acute type A aortic dissection. Initially, we attempted endovascular repair using a semi-custom-made thoracic fenestrated stent graft. However, this treatment failed due to an endoleak. Two weeks later, we performed a total arch vessel debranching using femoral artery inflow and thoracic endovascular repair. Postoperative computed tomography revealed no signs of the endoleak. This hybrid approach could be an effective treatment option for anastomotic pseudoaneurysms of the ascending aorta.

Midterm Outcomes of Primary and Secondary Use of an Endoanchor System for Thoracic and Abdominal Aortic Endovascular Aortic Repair

PURPOSE

To assess the safety, technical success, and midterm outcomes of endoanchor (Heli-FX, Medtronic, Santa Rosa, California) deployment in thoracic endovascular aortic repair (TEVAR) or abdominal endovascular aortic repair (EVAR).

MATERIALS AND METHODS

This single-institution, retrospective study of all endoanchor procedures was performed from February 1, 2017 to March 30, 2021. All procedures were performed percutaneously by interventional radiologists. Clinical information and outcome data were retrieved from electronic medical records. Fifty patients (14% females, n = 7; 86% males, n = 43; median age, 79 years [range, 56-93 years]) underwent Endoanchor procedures, with 349 Endoanchors implanted; 33 procedures were primary deployments (at initial stent deployment) and 17 were secondary deployments (previous stent deployment). For the primary group (4 TEVARs and 29 EVARs), indications were prophylactic (n = 30), hostile neck (n = 28), hostile distal landing zone (n = 2), and intraprocedural type 1a endoleaks (n = 3). For the secondary group (4 TEVARs and 13 EVARs), indications were graft migration (n = 8), seal zone expansion without proven endoleak (n = 7) (proximal [n = 4] or distal seal [n = 3]), and proven type 1a endoleak (n = 2).

RESULTS

Median number of endoanchors deployed per procedure was 7 (range, 3-10). Median time to deploy endoanchors was 22 minutes (range, 8-46 minutes). The technical success rate of Endoanchor was 99.7% (348/349). The 30-day mortality rate was 0%. The overall adverse event rate was 6% (n = 3). Reinterventions were performed in 12% of patients (n = 6). Median follow-up was 38 months (range, 2-71 months). Overall survival at 1 and 3 years was 95% and 85%, respectively. Overall freedom from type 1a endoleak at 1 and 3 years was 96% and 93%, respectively.

CONCLUSIONS

Endoanchor procedures are safe with excellent technical success rate and good midterm clinical outcomes.

Coiling embolization strategy for medium-to-giant-sized intracranial aneurysms treated with pipeline embolization device: a propensity score-weighted study

OBJECTIVES

We aim to investigate associations between different coil strategies and outcomes in the aneurysms treated by a pipeline embolization device (PED).

METHODS

Patients with medium-to-giant-sized aneurysms treated by PED were included. The total cohort was divided into PED-alone and PED-coiling groups, and the PED-coiling group was further divided into loose and dense packing subgroups. Multivariate logistic analyses and stabilized inverse probability of treatment weighting (sIPTW) were performed to investigate the relationships between coiling strategies and outcomes. Restricted cubic spline (RCS) curves were used to describe the coiling degree and angiographic outcome relationship.

RESULTS

A total of 398 patients with 410 aneurysms were included. Aneurysms treated with PED coiling had a lower incomplete occlusion rate (15.3% vs. 30.3%, p = 0.002), higher total perioperative complication rate (14.2% vs. 3.5%, p = 0.001), longer production time (142.14 min vs. 101.26 min, p < 0.001), and higher total cost ($45,158.63 vs. $34,680.91, p < 0.001) than those treated with PED alone. There were no differences in outcomes between the loose and dense packing subgroups. However, the total cost was higher in the dense packing group ($43,787.46 vs. $47,288.32, p = 0.001) than in the loose packing group. The result was still robust in the multivariate and sIPTW analyses. The RCS curves showed "L-shape" relationships between the coil degree and angiographic outcomes.

CONCLUSION

Compared with PED alone, PED coiling could improve aneurysm occlusion. However, it could also increase the total complication risk, prolong procedure time, and increase the total cost. Compared with loose packing, dense packing did not enhance the treatment effectiveness but increased the treatment cost.

CLINICAL RELEVANCE STATEMENT

The additional treatment effect from coiling embolization declines sharply after a certain point. Specifically, the aneurysm occlusion rate is roughly stable when the coil number is greater than 3 or the total coil length is longer than 150 cm.

KEY POINTS

• Compared with pipeline embolization device (PED) alone, PED combined with coiling can improve aneurysm occlusion. • Compared with PED alone, PED combined with coiling increases the total complication risk, cost, and prolongs procedure time. • Compared with loose packing, dense packing did not increase the treatment effectiveness but increased the cost.

Upper Extremity Access Has Worse Outcomes in F/BEVAR Using the VQI Dataset

BACKGROUND

Physician-modified endografts and custom-manufactured devices use branched and fenestrated techniques (F/BEVAR) to repair complex aneurysms. Traditionally, many of these are deployed through a combination of upper and lower extremity access. However, with newer steerable sheaths, you can now simulate upper extremity (UEM) access from a transfemoral approach. Single-institution studies have demonstrated increased risks of access site complications and stroke when UEM access is used. This study compares outcomes after F/BEVAR in a national database between total transfemoral (TTF) access and mixed UEM access.

METHODS

This study is an analysis of the Vascular Quality Initiative for all patients who underwent F/BEVAR from 2014 to 2021. Patients were stratified based on a TTF delivery of all devices versus any UEM access for deployment of target vessel stents. Primary outcomes included stroke, myocardial infarction (MI), and perioperative death. Secondary outcomes included access site hematoma, occlusion or embolization, operative time, fluoroscopy time, and technical success. Multivariable linear and logistic regression analyses were performed.

RESULTS

Three thousand one hundred forty six patients underwent an F/BEVAR: 2,309 (73.4%) TTF and 837 (26.6%) UEM. Logistic regression analysis indicated a two-fold increased risk of death and MI and a three-fold increased risk of stroke in the UEM group. Furthermore, there is decreased operative time (221 vs. 297 min, P < 0.001) and fluoroscopy time (62 vs. 80 min, P < 0.001) in the TTF group and no difference in technical success between groups (96% vs. 97%, P = 0.159). Finally, there was a decrease in access site hematoma 2.54% vs. 4.31% (P = 0.013), access site occlusion 0.61% vs. 1.91% (P = 0.001), and extremity embolization 2.17% vs. 3.58% (P = 0.026) in the TTF versus UEM group.

CONCLUSIONS

This study using Vascular Quality Initiative data demonstrates that patients who undergo an F/BEVAR using UEM access have an increased risk of perioperative MI, death, and stroke compared to TTF access.

Comparison of treatment outcomes and complications of coil embolization in elderly and very elderly patients with cerebral aneurysms: a propensity score matching analysis

PURPOSE

This single center study aims to compare the treatment outcomes and procedure-related complications of coil embolization in elderly patients (60-79 years) and very elderly patients (aged 80 years or older) with cerebral aneurysms.

METHODS

Data was collected from 504 elderly patients aged 60 years or older who underwent coil embolization for intracranial aneurysms from 2018 to 2021. The study evaluated patient-related and anatomical factors and assessed various outcomes, comparing results between groups using statistical analysis and propensity score matching.

RESULTS

A total of 503 cerebral aneurysms were analyzed from individuals aged 60-79 years (n = 472) and those aged 80 years or older (n = 31). The majority of the aneurysms were unruptured with an average size of 3.5 mm in height and 3.4 mm in width. The patients were compared using 1:1 propensity score matching, and no significant differences were found in factors other than age and aortic elongation. Logistic analysis revealed that being over 80 years old and having a severe aortic arch elongation were identified as risk factors for procedure-related events in both total and unruptured cases.

CONCLUSIONS

The study compared coil embolization treatment for cerebral aneurysms in patients aged 60-79 and over 80, finding no significant difference in treatment outcomes except for procedure-related events. Procedure-related events were associated with severe aortic arch elongation and being over 80 years old. Coil embolization can be considered safe and effective for patients over 80, but further trials are needed for accurate conclusions.

Aortic sodium [18F]fluoride uptake following endovascular aneurysm repair

OBJECTIVE

In patients with abdominal aortic aneurysms, sodium [18F]fluoride positron emission tomography identifies aortic microcalcification and disease activity. Increased uptake is associated with aneurysm expansion and adverse clinical events. The effect of endovascular aneurysm repair (EVAR) on aortic disease activity and sodium [18F]fluoride uptake is unknown. This study aimed to compare aortic sodium [18F]fluoride uptake before and after treatment with EVAR.

METHODS

In a preliminary proof-of-concept cohort study, preoperative and post-operative sodium [18F]fluoride positron emission tomography-computed tomography angiography was performed in patients with an infrarenal abdominal aortic aneurysm undergoing EVAR according to current guideline-directed size treatment thresholds. Regional aortic sodium [18F]fluoride uptake was assessed using aortic microcalcification activity (AMA): a summary measure of mean aortic sodium [18F]fluoride uptake.

RESULTS

Ten participants were recruited (76±6 years) with a mean aortic diameter of 57±2 mm at time of EVAR. Mean time from EVAR to repeat scan was 62±21 months. Prior to EVAR, there was higher abdominal aortic AMA when compared with the thoracic aorta (AMA 1.88 vs 1.2; p<0.001). Following EVAR, sodium [18F]fluoride uptake was markedly reduced in the suprarenal (ΔAMA 0.62, p=0.03), neck (ΔAMA 0.72, p=0.02) and body of the aneurysm (ΔAMA 0.69, p=0.02) while it remained unchanged in the thoracic aorta (ΔAMA 0.11, p=0.41).

CONCLUSIONS

EVAR is associated with a reduction in AMA within the stented aortic segment. This suggests that EVAR can modify aortic disease activity and aortic sodium [18F]fluoride uptake is a promising non-invasive surrogate measure of aneurysm disease activity.

Zone 2/3 lesion and emergency repair as potential mortality predictors of TEVAR for thoracic aortic pseudoaneurysm

OBJECTIVE

Thoracic aortic pseudoaneurysm (TAP) is an uncommon but life-threatening condition. The present study aimed to investigate the early and midterm clinical outcome of TAP patients following TEVAR and identify potential mortality predictors.

METHODS

We retrospectively reviewed a series of 37 eligible patients with TAP admitted to our hospital from July 2010 to July 2020. We explored their baseline, perioperative and follow-up data. Fisher exact test and Kaplan-Meier method were applied for comparing difference between groups.

RESULTS

There were 29 men and 12 women, with the mean age as 59.5 ± 13.0 years (range 30-82). The mean follow-up period was 30.7 ± 28.3 months (range 1-89). For early outcome (≤ 30 days), mortality happened in 3 (8.1%) zone 3 TAP patients versus 0 in zone 4 (p = 0.028); postoperative acute arterial embolism of lower extremity and type II endoleak respectively occurred in 1(2.7%) case. For midterm outcome, survival at 3 months, 1 year and 5 years was 88.8%, 75.9% and 68.3%, which showed significant difference between zone 2/3 versus zone 4 group (56.3% vs. 72.9%, p = 0.013) and emergent versus elective TEVAR group (0.0% versus 80.1%, p = 0.049). Previous stent grafting or esophageal foreign body with Aortoesophageal fistula (AEF), and systemic vasculitis, as etiologies, resulted in encouraging immediate outcome but worse midterm prognosis.

CONCLUSION

TAP lesions at zone 2/3 and emergent TEVAR predict worse midterm outcomes compared to zone 4 lesions and elective TEVAR. The outcomes are also mainly restricted by the etiology of the TAP.

Early results of frozen elephant trunk in acute type-A dissection in 1445 patients

BACKGROUND

We aimed to briefly describe the use of total arch replacement with frozen elephant trunk in our center's 12-year treatment of acute type A dissection and the early postoperative results. We summarized the practical experience of this procedure in our center and performed regression analyses to find the independent risk factors for major complications.

METHODS

Consecutive patients with acute type A dissection having surgical total arch replacement with the implantation of a frozen elephant trunk were collected from January 2010 to December 2021 and were included in the analysis. For each major operation-related complication, independent risk factors were identified using both univariate and multivariate regression models.

RESULTS

In our institution, the total arch replacement with frozen elephant trunk procedure is used more frequently each year and makes up 70% of the surgical procedures for acute type A dissection. The overall postoperative mortality rate was 6.2%, which declined as the techniques (including surgical procedures, organ perfusion protection etc.) improved. Other complications include: 11.7% for continuous renal replacement therapy, 5.7% for stroke, 17.8% for ICU stay longer than 7 days, 10.9% for prolonged mechanical ventilation, and so on. According to regression analysis, different major complications had different independent risk factors. Several factors, such as advanced age, impaired renal function, and extended cardiopulmonary bypass time, were found to be implicated in nearly all of the complications.

CONCLUSION

Total arch replacement plus frozen elephant trunk strategy is a safe surgical method for extensive acute type A dissection. Some factors, such as advanced age, impaired renal function, and prolonged cardiopulmonary bypass time, might be associated with poor prognosis.

Extra-anatomical left common carotid and subclavian artery bypass followed by aortic arch replacement with frozen elephant trunk

BACKGROUND

Total arch replacement (TAR) using a frozen elephant trunk (FET) allows for simultaneous treatment of the aortic arch and descending aortic pathology via median sternotomy. In addition, an extra-anatomical bypass performed between the left common carotid artery (CCA) and subclavian artery (SCA) prior to TAR allowed further proximalisation of the FET prosthesis, facilitated distal anastomosis of the TAR and spared the demanding left subclavian artery (LSA) anastomosis in the deep thorax. We investigated the efficacy of this debranching-first technique, followed by TAR using a frozen elephant trunk, as a two-stage operation for extensive thoracic aortic aneurysms in high-risk patients.

METHODS

Forty-nine consecutive patients with diffuse degenerative aneurysms from the aortic arch to the descending aorta or chronic aortic dissection who underwent left common carotid to subclavian artery bypass followed by TAR using a frozen elephant trunk and subsequent thoracic endovascular aortic repair between 2016 and 2021 were analysed. The baseline characteristics and clinical outcomes were assessed. The estimated overall survival, 5-year aortic event-free survival, and aortic reintervention rates were analysed.

RESULTS

The average European System for Cardiac Operative Risk Evaluation (EuroSCORE II) was 4.7 ± 2.5. The operative mortality rate was 4.1%, with no paraplegia events. The estimated 5-year overall survival, cumulative aortic-related mortality rates were 76.8% and 2%, respectively. The estimated 5-year overall cumulative aortic reintervention rate, including the intended intervention, was 31.3%. The estimated 5-year cumulative rate of non-intended reintervention was 4.5%.

CONCLUSIONS

The assessed technique enables a less technically demanding surgery with reasonable outcomes. The estimated 5-year aortic event-free survival and reintervention rates were acceptable, suggesting that multiple stages of alternative open and endovascular interventions, such as this technique, may reduce the morbidity and mortality rates of high-risk patients with diffuse thoracic aortic aneurysm. UMIN-CTR (University hospital Medical Information Network-Clinical Trial Registry) https://center6.umin.ac.jp/cgi-open-bin/ctr_e/index.cgi Clinical registration number: UMIN000051531.

Anatomical feasibility of a 'semi-custom' unibody single-branch endograft in previous zone 2 thoracic endovascular aortic repair

OBJECTIVES

The aim of this study was to evaluate the suitability of a subclavian unibody single-branch endograft among patients treated with thoracic endovascular aortic repair (TEVAR) in landing zone 2 (LZ2).

METHODS

This is a pre-clinical, single-centre, real-world, all-comers, retrospective cohort study. Patients treated with TEVAR in LZ2 with an available preoperative computed tomography angiography were included. The primary outcome was the anatomical feasibility of the Castor endograft in patients receiving endovascular treatment in LZ2 between 1999 and 2022. Secondary outcomes were: a comparison of feasible and unfeasible patients; frequencies and description of exclusion causes; non-feasibility risk factor analysis; and analysis of the stent graft configurations necessary to treat 75% of the patients. A logistic regression model was used to find associations between baseline morphological data and non-feasibility.

RESULTS

A total of 473 procedures were performed and 72 patients fulfilling inclusion criteria were included. The mean distance between the left carotid artery and left subclavian artery (or between innominate artery and bovine trunk) was 12.4 ± 5.2 mm and its average diameter was 33.0 ± 10.6 mm. The pre-vertebral left subclavian artery's diameter and length were 11.3 ± 2.5 and 38.7 ± 10.8 mm. Forty-nine (68.1%) patients were suitable for Castor implantation. Twenty-one configurations were required to treat 75% of feasible patients and might be lowered to 12 configurations applying less strict criteria.

CONCLUSIONS

The Castor endograft was anatomically feasible in several patients requiring TEVAR in LZ2. Three-quarters of feasible patients could be treated with a reasonable number of configurations, paving the path for future off-the-shelf applications.

Preliminary in-silico analysis of vascular graft implantation configuration and surface modification

Vascular grafts are used to reconstruct congenital cardiac anomalies, redirect flow, and offer vascular access. Donor tissue, synthetic, or more recently tissue-engineered vascular grafts each carry limitations spanning compatibility, availability, durability and cost. Synthetic and tissue-engineered grafts offer the advantage of design optimization using in-silico or in-vitro modeling techniques. We focus on an in-silico parametric study to evaluate implantation configuration alternatives and surface finishing impact of a novel silicon-lined vascular graft. The model consists of a synthetic 3D-generic model of a graft connecting the internal carotid artery to the jugular vein. The flow is assumed unsteady, incompressible, and blood is modeled as a non-Newtonian fluid. A comparison of detached eddy turbulence and laminar modeling to determine the required accuracy needed found mild differences mainly dictated by the roughness level. The conduit walls are modeled as non-compliant and fixed. The shunt configurations considered, are straight and curved with varied surface roughness. Following a grid convergence study, two shunt configurations are analyzed to better understand flow distribution, peak shear locations, stagnation regions and eddy formation. The curved shunt was found to have lower peak and mean wall-shear stress, while resulting in lower flow power system and decreased power loss across the graft. The curved smooth surface shunt shows lower peak and mean wall-shear stress and lower power loss when compared to the straight shunt.

Gore thoracoabdominal branched endoprosthesis: early results and impressions

The remarkable advances in technology and devices in the last two decades have made possible the endovascular repair of complex abdominal (cAAA) and thoracoabdominal (TAAA) aortic aneurysms with challenging anatomy. To date, despite the creation of multiple fenestrated/branched endografts intended to treat these difficult cases, in the USA, many of them remain available only under physician sponsored investigational device exemption (PSIDE) protocols in few institutions. The Gore Thoracoabdominal Branched Endoprosthesis (TAMBE; W.L. Gore & Associates, Flagstaff, AZ, USA) investigational device is a four-branched off-the-shelf (OTS) endograft that concluded an early feasibility study in 2016 and is currently finalizing a pivotal trial in pursuit of approval from the Food and Drug Administration. This article discusses the TAMBE early feasibility multicenter study results, the most relevant features of this device, its anatomical feasibility, and the impressions about this endograft as an OTS option for the treatment of CAAA and TAAA.

Computational study of fenestration and parallel grafts used in TEVAR of aortic arch aneurysms

To explore the differences between fenestration technique and parallel grafts technique of thoracic endovascular aortic repair, and evaluate the risk of complications after interventional treatment of aortic arch aneurysms. A three-dimensional aortic model was established from the follow-up imaging data of patient who reconstructed the superior arch vessel by the chimney technique, which was called the chimney model. Based on the chimney model, the geometric of the reconstructed vessel was modified by virtual surgery, and the normal model, fenestration model and periscope model were established. The blood flow waveforms measured by 2D phase contrast magnetic resonance imaging were processed as the boundary conditions of the ascending aorta inlet and the superior arch vessels outlets of the normal model. The pressure waveform of descending aorta was obtained using three-element Windkessel model, and specific pressure boundary conditions were imposed at reconstructed branches for the postoperative models. Through computational fluid dynamics simulations, the hemodynamic parameters of each model were obtained. The reconstructed vessel flow rate of the periscope model and the fenestration model are 33% and 50% of that of the normal model, respectively. The pressure difference between the inner and outer walls of the fenestration stent and periscope stent is 3.15 times and 7.56 times that of the chimney stent. The velocity in the fenestration stent and periscope stent is uneven. The high relative residence time is concentrated in the region around the branch stents, which is prone to thrombosis. The "gutter" part of the chimney model may become larger due to the effect of the stent-graft DF, increasing the risk of endoleak. For patients with incomplete circle of Willis, the periscope technique to reconstruct the supra-arch vessels may affect blood perfusion. It is recommended to use balloon-expandable stent for fenestration stent and periscope stent, and self-expanding stent for chimney stent. For patients with aortic arch aneurysms, the fenestration technique may be superior to the parallel grafts technique.

Outcomes of Elective and Non-elective Fenestrated-branched Endovascular Aortic Repair for Treatment of Thoracoabdominal Aortic Aneurysms

OBJECTIVE

To describe outcomes after elective and non-elective fenestrated-branched endovascular aortic repair (FB-EVAR) for thoracoabdominal aortic aneurysms (TAAAs).

BACKGROUND

FB-EVAR has been increasingly utilized to treat TAAAs; however, outcomes after non-elective versus elective repair are not well described.

METHODS

Clinical data of consecutive patients undergoing FB-EVAR for TAAAs at 24 centers (2006-2021) were reviewed. Endpoints including early mortality and major adverse events (MAEs), all-cause mortality, and aortic-related mortality (ARM), were analyzed and compared in patients who had non-elective versus elective repair.

RESULTS

A total of 2603 patients (69% males; mean age 72±10 year old) underwent FB-EVAR for TAAAs. Elective repair was performed in 2187 patients (84%) and non-elective repair in 416 patients [16%; 268 (64%) symptomatic, 148 (36%) ruptured]. Non-elective FB-EVAR was associated with higher early mortality (17% vs 5%, P <0.001) and rates of MAEs (34% vs 20%, P <0.001). Median follow-up was 15 months (interquartile range, 7-37 months). Survival and cumulative incidence of ARM at 3 years were both lower for non-elective versus elective patients (50±4% vs 70±1% and 21±3% vs 7±1%, P <0.001). On multivariable analysis, non-elective repair was associated with increased risk of all-cause mortality (hazard ratio, 1.92; 95% CI] 1.50-2.44; P <0.001) and ARM (hazard ratio, 2.43; 95% CI, 1.63-3.62; P <0.001).

CONCLUSIONS

Non-elective FB-EVAR of symptomatic or ruptured TAAAs is feasible, but carries higher incidence of early MAEs and increased all-cause mortality and ARM than elective repair. Long-term follow-up is warranted to justify the treatment.

Transatlantic multicenter study on the use of a modified preloaded delivery system for fenestrated endovascular aortic repair

OBJECTIVE

Analyze the outcomes of endovascular complex abdominal and thoracoabdominal aortic aneurysm repair using the Cook fenestrated device with the modified preloaded delivery system (MPDS) with a biport handle and preloaded catheters.

METHODS

A multicenter retrospective single arm cohort study was performed, including all consecutive patients with complex abdominal aortic aneurysm repair and thoracoabdominal aortic aneurysms treated with the MPDS fenestrated device (Cook Medical). Patient clinical characteristics, anatomy, and indications for device use were collected. Outcomes, classified according to the Society for Vascular Surgery reporting standards, were collected at discharge, 30 days, 6 months, and annually thereafter.

RESULTS

Overall, 712 patients (median age, 73 years; interquartile range [IQR], 68-78 years; 83% male) from 16 centers in Europe and the United States treated electively were included: 35.4% (n = 252) presented with thoracoabdominal aortic aneurysms and 64.6% (n = 460) with complex abdominal aortic aneurysm repair. Overall, 2755 target vessels were included (mean ,3.9 per patient). Of these, 1628 were incorporated via ipsilateral preloads using the MPDS (1440 accessed from the biport handle and 188 from above). The mean size of the contralateral femoral sheath during target vessel catheterization was 15F ± 4, and in 41 patients (6.7%) the sheath size was ≤8F. Technical success was 96.1%. Median procedural time was 209 minutes (IQR, 161-270 minutes), contrast volume was 100 mL (IQR, 70-150mL), fluoroscopy time was 63.9 minutes (IQR, 49.7-80.4 minutes) and median cumulative air kerma radiation dose was 2630 mGy (IQR, 838-5251 mGy). Thirty-day mortality was 4.8% (n = 34). Access complications occurred in 6.8% (n = 48) and 30-day reintervention in 7% (n = 50; 18 branch related). Follow-up of >30 days was available for 628 patients (88%), with a median follow-up of 19 months (IQR, 8-39 months). Branch-related endoleaks (type Ic/IIIc) were observed in 15 patients (2.6%) and aneurysm growth of >5 mm was observed in 54 (9.5%). Freedom from reintervention at 12 and 24 months was 87.1% (standard error [SE],1.5%) and 79.2% (SE, 2.0%), respectively. Overall target vessel patency at 12 and 24 months was 98.6% (SE, 0.3%) and 96.8% (SE, 0.4%), respectively, and was 97.9% (SE, 0.4%) and 95.3% (SE, 0.8%) for arteries stented from below using the MPDS, respectively.

CONCLUSIONS

The MPDS is safe and effective. Overall benefits include a decrease in contralateral sheath size in the treatment of complex anatomies with favorable results.

Outcomes and Economic Impact of Hypogastric Artery Management During Elective Endovascular Aortic Repair for Aorto-Iliac Aneurysms

BACKGROUND

To analyze clinical outcomes and perform a macro-costing evaluation of endovascular aortic repair (EVAR) for aorto-iliac aneurysms.

METHODS

This is a retrospective, financially unsupported, physician-initiated observational cohort study. Patients with iliac artery involvement treated with EVAR between January 1st, 2014 and December 31st, 2021 were identified. Inclusion criteria were intact aneurysm, elective EVAR with at least 1 hypogastric artery (HA) treatment, use of bifurcated endograft (EG), and at least 6 months of follow-up. Primary outcomes of interest were overall survival, freedom from aneurysm-related mortality (ARM), freedom from EVAR-related reintervention, and overall EVAR(procedure)-related costs.

RESULTS

We studied 122 (9.1%) patients: 119 (97.5%) were male and 3 (2.5%) females. Median age of patients was 76 years (range, 68.75-81). Overall, 107 (87.7%) patients had both HAs preserved according to following strategy: 45 (36.9%) with flared limbs, 13 (10.6%) with bilateral branched device, and 49 (40.2%) with a combination of flared limb on 1 side and branched device on the contralateral side. Bilateral overstenting was performed in 15 (12.3%) patients. Estimated overall survival was not different between groups of EVAR (Log-rank, P = 0.561). There was only 1 (0.8%) ARM ascertained during the follow-up. Estimated freedom from EVAR-related reintervention was not different among groups (Log-rank, P = 0.464). During the follow-up, 9 (7.4%) patients developed buttock claudication (Society for Vascular Surgery (SVS) grade 1, n = 4, SVS grade 2, n = 5), more frequently in HA overstenting (hazard ratio (HR): 3.6; 95% confidence intervals (CIs): 0.96-13.5, P = 0.058). When all cots were included, branched EVAR still carried the highest burden (P = 0.001) in comparison with the mixed subgroup, the overstenting subgroup, and the flared limbs subgroup.

CONCLUSIONS

Early mortality and pelvic ischemic syndromes rate were acceptably low in all techniques. Hypogastric artery preservation showed lower complication rate in comparison with HA overstenting which, however, appears to be safe an effective for option with similar overall costs for patients who are not candidates for HA preservation based on aortic anatomy.

A pilot study to evaluate a novel localized treatment to stabilize small- to medium-sized infrarenal abdominal aortic aneurysms

OBJECTIVE

There is no proven therapy to reduce growth rates of small- to medium-sized abdominal aortic aneurysms (AAAs). Ex vivo and animal studies have demonstrated that a novel stabilizing agent, 1,2,3,4,6-pentagalloyl glucose (PGG), delivered locally to the aneurysm sac, can bind to elastin and collagen to re-establish strength and resist enzymatic degradation. We aimed to demonstrate that a one-time administration of PGG solution to the aneurysm wall is safe and potentially effective to slow the growth of small- to medium-sized AAAs.

METHODS

Patients with small- to medium-sized infrarenal AAAs (maximum diameter <5.5 cm) were recruited. Via transfemoral access, a 14F or 16F dual-balloon delivery catheter was introduced into the aneurysm sac. A single, 3-minute, localized endoluminal infusion of PGG was delivered via a 'weeping' balloon to the aneurysm wall. Independent core laboratory measurements of maximum aneurysm sac diameter and sac volume measurements based on computed tomography angiography (CTA) were used for assessments at 1, 6, 12, 24, and 36 months. The primary endpoints were technical success and safety (major adverse events at 30 days). The secondary endpoint was growth stabilization, defined as freedom from aneurysm sac enlargement (diameter increase >5 mm per year or volume increase of >10% per year).

RESULTS

Twenty patients (19 male) were enrolled at five centers from May 2019 to June 2022 (mean age, 67.8 years; range, 50-87 years). All procedures were technically successful. The safety profile was consistent with standard interventional procedures. Four patients demonstrated transient elevations of liver enzymes levels that returned to normal by 30 days with no clinical symptoms. Through November 2022, follow-up CTA data is available on the first 11 patients. The average changes in maximum aneurysm diameter from baseline to 6, 12, 24, and 36 months were 0.2 mm, 1.1 mm, 1.2 mm, and 0.8 mm, respectively, and the average changes in volume were 2.0%, 9.6%, 18.1%, and 11.6%, respectively. At 12 months, none of the aneurysms showed growth >5.0 mm, and three had volume growth >10%.

CONCLUSIONS

The early results of this first-in-human, small cohort study demonstrated that a single, localized PGG administration to patients with small- to medium-sized infrarenal AAAs is safe. Longer term follow-up on all 20 treated patients is needed to better assess the potential impact on aneurysm growth.

Anatomic Utility of Single Branched Thoracic Endograft During Thoracic Endovascular Aortic Repair

INTRODUCTION

Single branched thoracic endografts (SBTEs) have been designed for pathology requiring zone 2 seal during thoracic endovascular aortic repair (TEVAR). Numerous criteria must be met to allow for their implantation. Our aim was to analyze anatomic suitability for a next generation SBTE.

METHODS

We reviewed 150 TEVAR procedures between 2015 and 2019. Proximal seal was: zone 0 in 21 (16%), zone 1 in 4 (3%), zone 2 in 52 (40%), zone 3 in 45 (35%), and zone 4 or distal in 7 (5%). We analyzed the Zone 2 patient's angiograms and CT angiograms using centerline software to measure arterial diameters and length in relation to the left common carotid artery (LCCA), left subclavian artery (LSA) and proximal extent of aortic disease to determine if patients met anatomic criteria of a novel SBTE.

RESULTS

Zone 2 average age was 64.4 ± 16.3 years; 34 patients were male (65%). Indications for repair were aneurysm (N = 9, 17%), acute dissection (N = 14, 27%), chronic dissection with aneurysmal degeneration (N = 7, 13%), intramural hematoma (N = 9, 17%), penetrating aortic ulcer (N = 5, 10%), and blunt traumatic aortic injury (BTAI, N = 8, 15%). LSA revascularization occurred in 27 patients (52%). Overall, 20 (38.5%) of the zone 2 patients met anatomic criteria. Patients with dissection met anatomic criteria less frequently than aneurysm (33% [10 of 30] vs 64% [9 of 14]). Patients treated for BTAI rarely met the anatomic criteria (1 of 8, 13%). The main anatomic constraints were an inadequate distance from the LCCA to the LSA takeoff and from the LCCA to the start of the aortic disease process.

CONCLUSION

Less than half of patients who require seal in zone 2 met criteria for this SBTE. Patients with aneurysms met anatomic criteria more often than those with dissection. The device would have little applicability in treating patients with BTAI.

Renovisceral artery alterations due to branched endovascular aortic repair and respiratory-induced deformations

OBJECTIVE

This study quantified respiratory-induced dynamics of branch vessels before and after thoracoabdominal aortic aneurysm (TAAA) branched endovascular aneurysm repair (bEVAR).

METHODS

Patients with TAAA were recruited prospectively and treated with bEVAR, predominantly with Zenith t-Branch and BeGraft Peripheral PLUS bridging stents. Using SimVascular software, three-dimensional geometric models of the vessels and implants were constructed from computed tomography angiograms during both inspiratory and expiratory breath-holds, preoperatively and postoperatively. From these models, branch take-off angles, end-stent angles (transition from distal end of stent to native artery), and curvatures were computed. Paired, two-tailed t tests were performed to compare inspiratory vs expiratory geometry and pre- vs postoperative deformations.

RESULTS

We evaluated 52 (12 celiac arteries [CA], 15 superior mesenteric arteries [SMA], and 25 renal arteries [RA]) branched renovisceral vessels with bridging stents in 15 patients. Implantation of bridging stents caused branch take-off angle to shift inferiorly in the SMA (P = .015) and RA (P = .014) and decreased the respiratory-induced branch angle motion in the CA and SMA by approximately 50%. End-stent angle increased from before to after bEVAR for the CA (P = .005), SMA (P = .020), and RA (P < .001); however, respiratory-induced deformation was unchanged. Bridging stents did not experience significant bending owing to respiration.

CONCLUSIONS

The decrease in respiratory-induced deformation of branch take-off angle from before to after bEVAR should decrease the risk of device disengagement and endoleak. The unchanging respiratory-induced end-stent bending, from before to after bEVAR, means that bEVAR maintains native vessel dynamics distal to the bridging stents. This factor minimizes the risk of tissue irritation owing to respiratory cycles, boding well for branch vessel patency. The longer bridging stent paths associated with bEVAR may enable smoother paths subject to less dynamic bending, and potentially lower fatigue risk, compared with fenestrated EVAR.

Sex different abdominal artery anatomy may induce different displacement force on stent-graft after endovascular aneurysm repair

Women with abdominal aortic aneurysm (AAA) have a higher incidence of complications after Endovascular aneurysm repair (EVAR), most of which are related to the migration of stent-graft. The different force acting on the stent-graft after EVAR caused by different abdominal artery anatomy of male and female AAA patients may be the reason for the sex-different complications. This article aims to explore the possible biomechanical mechanisms of sex differences by making a comparison of displacement force acting on the stent graft of male and female AAA patients. To explore the effect of different vascular anatomy on stent-graft migration, the uniformed models were constructed according to the specific vascular anatomy parameters of AAA patients of different sex, which have been measured before. The computational fluid dynamics method was used to quantitate the pulsatile force acting on the stent-graft after EVAR in a cardiac cycle. Then the displacement force was calculated with the pressure and the wall shear stress, and the total and area-weighted average of displacement force acting on the stent-graft were compared respectively. In one cardiac cycle, the wall pressure for the male model is greater than that of the female model (2.7-4.4 vs. 2.2-3.4 N), and the wall shear force for the female model is slightly greater (0-0.0065 vs. 0-0.0055 N). The displacement force is mainly provided by the wall pressure, which is also greater in the male model. However, the area-averaged displacement force is greater for the female model than that for the male model (180-290 vs. 160-250 Pa). Because of the different vascular anatomies, the impact caused by the pulsating aortic blood flow on the AAA stent-graft of women after EVAR was greater than that of men. Women's vascular anatomy leads to greater area-averaged displacement force after stent-graft implantation, resulting in a greater risk of stent-graft migration, which might be one of the reasons why women had a higher incidence of complications after EVAR.