Complications of endovascular aneurysm repair of the thoracic and abdominal aorta: evaluation and management

Feasibility of ultra-high-resolution abdominal CT angiography in PCCT in outperforming conventional EICT

OBJECTIVE

Photon-Counting Computed Tomography (PCCT) offers significant advancements in aortic imaging, especially for vascular applications. Its Ultra-High-Resolution (UHR) mode enhances the visualization of small vascular structures, aiding surgical planning while reducing radiation exposure. This study assesses whether UHR abdominal aortic angiography with PCCT improves resolution and noise ratio compared to Energy-Integrating Computed Tomography (EICT) without increasing radiation dose.

METHODS

In this retrospective study, 25 patients underwent Ultra-High-Resolution abdominal CT angiography (PCCT) and were compared to 25 patients, who underwent abdominal CT angiography on an EICT scanner. Ethical approval was obtained. Image quality was assessed using Signal-to-Noise Ratio (SNR), Contrast-to-Noise Ratio (CNR), and a five-point Likert scale. Radiation doses were compared using CTDIvol, DLP, and effective dose, with statistical significance set at p < 0.05.

RESULTS

The PCCT group showed significantly lower radiation exposure (CTDIvol: 4.7 mGy vs. 7.3 mGy, p = 0.0081; effective dose: 3.4 mSv vs. 6.5 mSv, p = 0.0057). Although PCCT had higher SNR and CNR, differences were statistically significant only for renal arteries (p = 0.0432). Subjective image quality was significantly better for PCCT (p < 0.0001).

CONCLUSION

This study outlines the feasibility of UHR mode using PCCT in improving the contrast-to-noise and signal-to-noise ratio in patients undergoing abdominal CT angiography in the arterial phase as well as improved image quality of visceral arteries compared to EICT, accompanied by a significant reduction in radiation dose. This supports its recommending PCCT angiography for use in reducing patient exposure while improving image quality.

A Systematic Review of Transcarotid Approach for Endovascular Aortic Repair in Treating Aortic Disease

PurposeThe purpose of this study is to evaluate the feasibility, efficacy, and safety of transcarotid approach endovascular aortic repair (EVAR) in patients where conventional femoral access is not possible.Materials and MethodsA systematic review of all articles discussing transcarotid approach EVAR published in the PubMed, Embase, Ovid, Web of Science, and Cochrane Library databases were conducted. This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.ResultsIn accordance with the inclusion criteria, 17 articles discussing transcarotid approach EVAR were retrieved, encompassing 18 patients. Among these patients, 6 patients were related to ascending aortic disease, including 4 cases of pseudoaneurysms, 1 case of penetrating ulcer, and 1 case of dissection. 9 patients had descending aortic disease, comprising 6 aneurysms, 2 penetrating ulcers, and 1 pseudoaneurysm. There were 3 cases of abdominal aortic disease, including 2 aneurysms and 1 endoleak. Among these patients, 10 cases had access through the left common carotid artery, and 8 cases had access through the right common carotid artery. One patient experienced spinal cord ischemia and subsequently died of multi-organ failure caused by acute pancreatitis. Additionally, there was one case of minor embolization in the nonsurgical carotid supply area. No cerebral infarctions were observed in the vascular territory of the ipsilateral carotid artery at the surgical approach site.ConclusionsResearch on transcarotid approach EVAR is limited and predominantly consists of case reports, with a notable absence of randomized controlled trials. This systematic review suggests that transcarotid approach EVAR may be a viable alternative for selecting patient groups when the conventional femoral artery approach is not feasible. These findings indicate that this method is associated with a relatively manageable perioperative complications and mortality rates.

Predictive factors for size change of aorta in patients with acute blunt traumatic aortic injury

OBJECTIVE

We aimed to investigate the changes in aorta size, the factors affecting size changes in patients with acute blunt traumatic aortic injury and to evaluate the adequacy of the current 120% thoracic endovascular aortic repair graft oversizing policy.

DESIGN AND METHODS

This retrospective review study was conducted using the prospectively collected medical records of 45 patients (mean age: 53.5 years, male: 39 patients) with blunt traumatic aortic injury treated at a level 1 trauma center between 2012 and 2021. Aortic diameter was measured by computed tomography angiographic images at four different levels [ascending aorta (A), isthmus (B), descending thoracic aorta (C), and infrarenal aorta (D)] on arrival and follow-up (median time interval, 13 days). Associated factors including patient characteristics and hemodynamic parameters on arrival and follow-up were collected to determine their influence on changes in the aorta.

RESULTS

The mean diameter of all four aortic levels increased on follow-up computed tomography compared to initial computed tomography (A: + 11.77%, B: + 10.19%, C: + 7.71%, D: + 12.04%). Patient age and injury severity score influenced changes in the diameter of the ascending aorta (P < 0.05). Patient age and blunt traumatic aortic injury grade were significantly associated with changes in the infrarenal aortic diameter (P < 0.05). Three cases of type 1 endoleak were observed at follow-up but all were spontaneously resolved without further intervention at next computed tomography follow-up.

CONCLUSIONS

In patients with acute blunt traumatic aortic injury, aortic diameter is significantly smaller by about 10% under shock and is not considered a basis for oversizing the currently implemented 120% thoracic endovascular aortic repair graft sizing. However, in young patients under the age of 40, the change is significantly large and subsequent computed tomography follow-up is required.

Mechanical Thrombectomy for the Management of Acute Branch Occlusions in Patients who Previously Underwent Fenestrated/Branched Endovascular Repair for Thoracoabdominal Aneurysm

BACKGROUND

Acute thrombosis of visceral artery branch stents represents a rare but potentially devastating complication among patients who have undergone fenestrated and branched endovascular repair (F/BEVAR) for the treatment of thoracoabdominal aortic aneurysm (TAAA). There is limited data regarding the optimal management strategy in these patients. In this study, we describe the management and outcomes of patients who presented with this complication and were subsequently treated with the use of percutaneous mechanical thrombectomy.

METHODS

A retrospective review of all patients enrolled in a single-institution, physician-sponsored investigational device exemption trial for endovascular repair of thoracoabdominal aneurysms (F/BEVAR) from 2012 to 2024 was performed. Patients who presented during the long-term follow-up period with acute graft thrombosis and treated with percutaneous mechanical thrombectomy were identified, and their preoperative course, hospital management, and long-term follow-up are described.

RESULTS

3 patients (1.3%) were identified with acute mesenteric ischemia or acute kidney injury due to branch graft occlusion and were subsequently treated with percutaneous mechanical thrombectomy. All patients were on a statin and an antiplatelet agent at the time of presentation, and the time from symptom onset to presentation was between 11 hr and 1 week. Patient 1 had complete occlusion of all 4 visceral artery branches. Patient 2 had occlusion of the celiac and superior mesenteric arteries (SMA), and patient 3 had occlusion of the right renal artery. All had successful return of vessel patency following mechanical thrombectomy, with an average fluoroscopy time of 15.5 min. All were spared bowel resection or permanent need for dialysis, and in each of the 7 affected vessels, patency was intact on long-term follow-up.

CONCLUSION

Percutaneous mechanical thrombectomy represents a viable treatment modality for patients with acute thrombosis of branch stents following F/BEVAR, including those who present in extremis or with multivessel involvement. Given the rapid rate of flow restoration, this technique may represent the optimal treatment modality for this patient population.

Atherosclerotic Abdominal Aortic Aneurysms on Computed Tomography Angiography: A Narrative Review on Spectrum of Findings, Structured Reporting, Treatment, Secondary Complications and Differential Diagnosis

Atherosclerotic abdominal aortic aneurysms (AAAs) are a common vascular pathology with significant morbidity and mortality risks. Timely diagnosis, accurate characterization, and standardized reporting are critical for effective management and monitoring of atherosclerotic AAAs. Imaging modalities, particularly computed tomography angiography (CTA), play a pivotal role in the detection, treatment planning, and identification of both primary and secondary complications, as well as distinguishing AAAs from other etiologies. This narrative review provides a comprehensive exploration of the spectrum of imaging findings in atherosclerotic AAAs on CTA, underscoring the importance of structured reporting. Additionally, it examines therapeutic approaches and complications, and it differentiates AAAs from inflammatory, mycotic, and traumatic variants, serving as a primer for radiologists in AAA evaluation.

Aortic endograft infection after thoracic endovascular aortic repair: two case reports and literature review

With the maturity of thoracic endovascular aortic repair (TEVAR) technology and its increasing application in clinical practice, complications and long-term management after TEVAR have become issues of concern. Here, we report two cases of TEVAR for thoracic aortic dissection. One patient developed recurrent fever 6 years after TEVAR and underwent multiple courses of antibiotic therapy with a poor response. He came to our hospital 6 months later and presented with gastrointestinal bleeding. Imaging revealed the presence of an aortic abscess around the stent graft involving the esophagus and mediastinum. The patient's condition deteriorated rapidly after admission, and he ultimately succumbed to hemorrhagic shock. Another patient developed recurrent fever 1 year after surgery. Imaging studies suggested an aortic abscess with involvement of the esophagus, and the patient chose conservative treatment. After long-term anti-infective treatment, the infected lesions remained but had decreased in size. Aortic endograft infection complicated by multiple organ involvement is a rare complication of TEVAR and has a high mortality rate. After an extended postsurgical period, patients who have undergone TEVAR often lack regular follow-up and are easily overlooked. Our cases highlight the importance of early prevention, early diagnosis, and appropriate management of late complications following TEVAR.

Effectiveness of single-energy metal artifact reduction algorithm in CT: application to contrast-enhanced CT with EVAR and coil embolization

This study aimed to evaluate the efficacy of the single-energy metal artifact reduction (SEMAR) algorithm in reducing metal artifacts and enhancing image quality in contrast-enhanced computed tomography (CT) for patients undergoing endovascular aneurysm repair (EVAR) with coil embolization. Thirty-eight patients (mean age 81.0 ± 6 years; 31 men, 7 women) who underwent contrast-enhanced CT following EVAR and internal iliac artery coil embolization between September 2022 and May 2023 were retrospectively analyzed. The Artifact Index (AI) quantified metallic artifacts from internal iliac artery aneurysm coils in CT images, calculated from the standard deviation of the artifact-containing region relative to a reference region. CT values of the external iliac artery at the same slice were also evaluated and compared. Two radiologists independently performed qualitative assessments of SEMAR and non-SEMAR images. SEMAR significantly reduced metal artifacts, decreasing the AI from 171.9 ± 74.5 HU to 35.8 ± 16.9 HU (p < 0.001). The mean CT values of the external iliac artery were similar for SEMAR (259.4 ± 63.7 HU) and non-SEMAR (257.1 ± 63.6 HU, indicating no significant difference. Qualitative assessment scores improved significantly with SEMAR (from 1.0 ± 0.0 to 2.5 ± 0.5; p < 0.001), enhancing visualization of internal iliac artery aneurysms. Interobserver agreement was high (κ = 0.83). The SEMAR algorithm effectively reduces metal artifacts in contrast-enhanced CT, significantly enhancing image quality without altering adjacent artery CT values. These improvements enhance the image quality of post-operative assessments in patients undergoing EVAR with coil embolization.

Management of Acute Diverticulitis and Incidental Abdominal Aortic Aneurysm in a 67-Year-Old Male: A Case Report of Balancing Priorities in a High-Risk Patient

Diverticular disease and abdominal aortic aneurysms (AAAs) represent distinct but significant clinical entities often associated with advanced age. Diverticulitis, a common complication of diverticular disease, can result in perforation and systemic complications, while AAAs, frequently asymptomatic, carry substantial morbidity and mortality risks if undetected or untreated. Advances in imaging have improved the early identification of these conditions, yet the simultaneous management of both presents unique challenges requiring multidisciplinary coordination. A 67-year-old male with a history of ST-elevation myocardial infarction, hypertension, hyperlipidemia, and smoking presented with left lower quadrant abdominal pain and abnormal outpatient computed tomography (CT) findings. Imaging revealed Hinchey 1a diverticulitis with a microperforation and an incidental 6.5 cm saccular AAA. The patient received conservative treatment for diverticulitis with intravenous antibiotics and transitioned to oral antibiotics upon clinical improvement. Following resolution, the patient underwent successful endovascular aneurysm repair (EVAR) for the AAA, which was complicated by a type II endoleak identified postoperatively. Blood pressure management and hydration addressed acute kidney injury, and the patient recovered well with a multidisciplinary follow-up planned. This case underscores the importance of imaging in diagnosing coexisting conditions, particularly in high-risk populations. Management required balancing the risks of treating acute diverticulitis with the need for prompt intervention for a large, saccular AAA. The conservative approach to diverticulitis, followed by elective EVAR, reflects a patient-centered strategy consistent with current guidelines. Furthermore, it underscores the critical role of adhering to screening recommendations for high-risk populations, as timely detection of asymptomatic conditions like AAAs can prevent life-threatening complications.

Recurrent peripheral ischemia following endovascular repair of an infrarenal aortic aneurysm: what did we miss?

We document a case of a 75-year-old patient with a history of hypercholesterolemia and hypertension, who underwent endovascular aortic repair (EVAR) for an infrarenal abdominal aortic aneurysm (AAA) with common iliac artery ectasia. Despite an initially successful procedure, the patient experienced recurrent episodes of acute limb ischemia in his right leg. Subsequent imaging revealed thrombus formation distal to the stent graft, constituting a potential source of embolization, which warranted a reevaluation of the treatment strategy. This case highlights some of the complexities associated with managing AAA patients. In the context of EVAR, it emphasizes the significance of careful patient selection, meticulous endograft implantation, and watchful follow-up while tailoring treatment according to individual patient needs and anatomical considerations.

Are current follow-up intervals justified in patients with non-emergent aortic surgeries?

OBJECTIVES

Evidence for different surveillance protocols following aortic treatment is still lacking. The aim of this study was to analyse the clinical relevance of a first follow-up visit after 6 months.

METHODS

Between January 2018 and December 2019, 464 patients treated for non-emergent aortic pathologies were retrospectively analysed. The incidence of aortic events during follow-up (ie, death, reintervention, endoleaks, anastomotic/new aneurysms and diameter progression over time) was investigated. A discrete-time non-homogeneous Markov Chain Model was used to analyse the data and to arrive at the number of skipped 6-month follow-up visits needed to harm a patient.

RESULTS

After 6 months, 2 (1.77%) patients had died, 15 (15.31%) patients suffered from aortic events and a total of 4 (3.67%) patients had undergone reintervention after endovascular surgery, compared to 0 deaths, 2 (0.59%) patients with aortic events and 5 (1.48%) reinterventions after open surgery. In our Markov Chain Model, after 6 months, 4.75% of patients showed aortic events, received a reintervention or died. Sixty patients would need to skip their 6-month follow-up visit for one indication for reintervention to go unnoticed. Only 24 would need to skip it for one complication to go by unnoticed. This number is 55 after open surgery and 9 after endovascular surgery.

CONCLUSIONS

After elective endovascular or open aortic surgery without immediate in-hospital postoperative aortic events, the first follow-up visit after 6 months is important. Extending the first interval to longer time periods might lead to a considerable increase in missed aortic events. The cost and radiation exposure of frequent follow-ups must be balanced against the benefits of early preventative aortic interventions, warranting further research.

Thymidine Phosphorylase Promotes Abdominal Aortic Aneurysm via VSMC Modulation and Matrix Remodeling in Mice and Humans

Background: Thymidine phosphorylase (TYMP) promotes platelet activation and thrombosis while suppressing vascular smooth muscle cell (VSMC) proliferation. Both processes are central to the development and progression of abdominal aortic aneurysms (AAAs). We hypothesize that TYMP plays a role in AAA development. Methods: Male wild-type (WT) C57BL/6J and Tymp-/- mice, fed a Western diet (WD) (TD.88137), were subjected to the 4-week Ang II infusion-induced AAA model. AAA progression was monitored by echography and confirmed through necropsy. Whole-body inflammation was assessed using a plasma cytokine array. Mechanistic studies were conducted using TYMP-overexpressing rat VSMC cell lines and primary VSMCs cultured from WT and Tymp-/- mouse thoracic aortas. Histological studies were performed on human AAA and normal aorta samples. Results: Elevated TYMP levels were observed in human AAA vessel walls. While WT mice exhibited a 28.6% prevalence of Ang II infusion-induced AAA formation, Tymp-/- mice were protected. TYMP enhanced MMP2 expression, secretion, and activation in VSMCs, which was inhibited by tipiracil, a selective TYMP inhibitor. Systemically, TYMP promoted proinflammatory cytokine expression, and its absence attenuated TNF-α-induced MMP2 and AKT activation. WT VSMCs treated with platelets lacking TYMP showed a higher proliferation rate than cells treated with WT platelets. Additionally, TYMP increased activated TGFβ1 expression in cultured VSMCs and human AAA vessel walls. In WT VSMCs, TYMP augmented thrombospondin-1 type 1 repeat domain (TSR)-stimulated TGFβ1 signaling, increasing connective tissue growth factor and MMP2 production. TSR also enhanced AKT activation in WT VSMCs but had the opposite effect in Tymp-/- cells. TSR-enhanced MMP2 activation in WT VSMCs was attenuated by LY294002 (a PI3K inhibitor) but not by SB431542 (a TGFβ1 inhibitor); both inhibitors had indiscernible effects on Tymp-/- VSMC. Conclusion: TYMP emerges as a novel regulatory force in vascular biology, influencing VSMC function and inflammatory responses to promote AAA development.

A bibliometric analysis of abdominal aortic aneurysm (2014-2024)

Background

Abdominal aortic aneurysm (AAA) is a localized bulge of the abdominal aorta, which mainly manifests as a pulsatile mass in the abdomen. Once an abdominal aortic aneurysm ruptures, the patient's life is seriously endangered. Surgery is the preferred treatment for abdominal aortic aneurysm. At present, there has been no comprehensive review of the current status of abdominal aortic aneurysm research. Therefore, this study aimed to identify global trends in abdominal aortic aneurysm research over the last 10 years through bibliometric analysis and to inform clinical practice, research funding allocation, and decision-making.

Methods

We downloaded research articles and reviews on abdominal aortic aneurysm from 1 January 2014, to 1 March 2024, from the Web of Science core collection. CiteSpace (version 6.2.1), RStudio and VOSviewer (version 1.6.18) were used for visual analysis of regional distribution, institutions, authors, keywords and other information.

Results

The number of documents on abdominal aortic aneurysm research increased continuously and has stabilized in recent years. A total of 9,905 publications from 67 countries were published from 1 January 2014, to 1 March 2024. A total of 2,142 (29.52%) studies were from the United States, 1,293 (13.05%) were from China, and 919 (9.28%) were from the United Kingdom. A total of 205 studies were conducted at Stanford University, 172 were conducted at Harvard Medical School, and 165 were conducted at the Mayo Clinic. The top three coauthorship authors were Schermerhorn, Marc L (114); Golledge, Jonathan (102); and De Vries, Jean Paul P.M. (74). The most cocited reference was Chaikof EL, 2018, J Vasc Surg, v67, p. 2; the most cocited journal was the Journal of Vascular Surgery; and the most cocited author was Lederle, FA. "Abdominal aortic aneurysm" was the most frequently used author keyword (2,492). Twenty-five references with strong citation bursts were identified by "CiteSpace". "Artificial intelligence", "clinical outcomes" and "bridging stent" were the primary keywords of emerging research hotspots.

Conclusion

This is the first bibliometric study to comprehensively summarize the research trends in abdominal aortic aneurysm research. This information can help us to identify the current research hotspots and directions. This study will provide extensive help for future research.

Influence of endovascular surgery on abdominal aortic aneurysm management strategies from a national health insurance database survey

BACKGROUND

Abdominal aortic aneurysm (AAA) is a significant global health concern, yet comprehensive population-based studies remain limited. This study aimed to evaluate the hospitalization rates, surgical trends, mortality, and reintervention rates for ruptured (r-AAA) and nonruptured (nr-AAA) AAA using data from a national health insurance database.

METHODS

A population-based retrospective cohort study was conducted utilizing data from the Taiwanese National Health Insurance Research Database from 2007 to 2018. The study included individuals aged 20 years and older with a newly diagnosed AAA.

RESULTS

Among 70 457 patients diagnosed with aortic aneurysm or dissection, 22 538 (32%) adult patients (≥20 years) were identified with AAA. The annual incidence of AAA ranged from 7.7 to 10.3 per 100 000 population, with r-AAA decreasing from 1.3 to 0.8 per 100 000 and nr-AAA from 9.0 to 6.8 per 100 000. Most patients with AAA were older adults (85%), with 15 392 (68%) hospitalized and 4885 (32%) undergoing surgery within 14 days of diagnosis. The use of endovascular aneurysm repair (EVAR) significantly increased from 28% to 96% over the study period. Long-term survival was higher in patients who underwent open surgical repair (OSR) compared to those who received EVAR or conservative management, irrespective of whether they had r-AAA or nr-AAA.

CONCLUSION

AAA predominantly affects older individuals, and the annual incidence shows a declining trend. Since the introduction of EVAR, its use has steadily increased while OSR rates have decreased. Although both EVAR and OSR are associated with reduced mortality in patients with r-AAA, OSR is linked to superior long-term survival outcomes.

Biodesign: Engineering an aortic endograft explantation tool

Endovascular aortic repair (EVAR) graft failure can be as high as 16% to 30% owing to endoleak, graft migration, or infection, often necessitating explantation, leading to potential morbidity (31%) and mortality (6.3%). Graft prongs frequently tear through the endothelium during explantation, leading to endothelial damage and subsequent fatal bleeding. The current standard of care involves different suboptimal techniques such as the syringe technique in which a cylinder is improvised by cutting a syringe in half and pushed over the graft hooks in a rotating motion, until covered for manual explantation. Because there is no commercially available product to address this shortcoming in graft explantation, we engage in the biodesign process to produce a functional explantation device. We designed and prototyped multiple potential solutions to remove EVAR endografts safely. Silicone tubing with EVAR endografts deployed in the lumen were used to simulate a grafted aorta and test each prototype. Prototypes were compared in their ability to meet design criteria including decrease in graft diameter, prevention of arterial dissection, ease of use, and decrease in procedure time. After determining the single best prototype, surgeon feedback was elicited to iteratively improve the original design. The most effective design uses a tapered lumenal geometry that decreases the EVAR graft diameter and uses stainless steel beads to prevent shear stress to the simulated aorta. A distal grip allows for easy single hand manipulation of the device, while a latching mechanism allows for smooth placement and removal over the endograft. After rigorous prototyping, our device proved feasible and effective for safe EVAR explantation, allowing this procedure to be performed safely.

Neuroprotective Effects of Chaperonin Containing TCP1 Subunit 2 (CCT2) on Motor Neurons Following Oxidative or Ischemic Stress

Chaperonin containing TCP1 (CCT) is an essential protein that controls proteostasis following spinal cord damage. In particular, CCT2 plays an important role in neuronal death in various neurological disorders; however, few studies have investigated the effects of CCT2 on ischemic damage in the spinal cord. In the present study, we synthesized a cell-permeable Tat-CCT2 fusion protein and observed its effects on H2O2-induced oxidative damage in NSC34 motoneuron-like cells and in the spinal cord after ischemic injury. Tat-CCT2, but not its control protein CCTs, was delivered into NSC34 cells in a concentration- and incubation time-dependent manner, and a clear cytosolic location of the delivered protein was observed. In addition, the delivered protein gradually degraded, and nearly control levels were observed 24 h after Tat-CCT2 treatment. Tat-CCT2 treatment significantly ameliorated 200 µM H2O2-induced neuronal damage in NSC34 cells at 8.0 µM protein treatment. Additionally, Tat-CCT2 significantly ameliorated H2O2-induced reactive oxygen species formation and DNA fragmentation. In the rabbit spinal cord, Tat-CCT2 was efficiently delivered into the spinal cord 4 h after 0.125 mg/kg protein treatment. In addition, treatment with Tat-CCT2 significantly improved the neurological scores based on the Tarlov criteria 24 and 72 h after ischemia/reperfusion. Moreover, the number of surviving neurons in the ventral horn of the spinal cord was significantly increased in the Tat-CCT2-treated group 3 and 7 days after ischemia compared to vehicle-treated group. Treatment with Tat-CCT2 alleviated the ischemia-induced oxidative stress and ferroptosis-related factor (malondialdehyde, 8-iso-prostaglandin F2α, and high mobility group box 1) and pro-inflammatory cytokine (interleukin-1β, interleukin-6, and tumor necrosis factor-α) releases in the ventral horn of the spinal cord 8 and 24 h after ischemia/reperfusion. In addition, Tat-CCT2 treatment significantly ameliorated ischemia-induced microglial activation in the ventral horn of spinal cord 24 h after reperfusion. These results suggest that Tat-CCT2 mitigates ischemia-induced neuronal damage in the spinal cord.

Real world experience with the TREO device in standard EVAR: Mid-term results of 150 cases from a German Multicenter study

Background: The objective of the study was to analyze mid-term results of unselected patients treated with the TREO (Terumo Aortic, Florida, USA) device at six German hospital sites. Methods: A multicenter, retrospective analysis of patients treated within and outside instructions for use (IFU) from January 2017 to November 2020 was performed. Primary outcomes were technical success, mortality and endograft related complications according to IFU status. Secondary outcomes were aneurysm/procedure related re-interventions. Results: 150 patients (92% male, mean age 73 ±8 years) were treated (within IFU 84% vs. outside IFU 16%) with the TREO device for abdominal aortic aneurysms (n=127 intact, n=17 symptomatic and n=6 ruptured; p=0.30). Technical success was achieved in 147/150 (within IFU 99% vs. outside IFU 92%, p=0.08). 30-day mortality was 2%, one year and overall mortality was 3% and 5%. During a mean follow-up of 28.4 months (range: 1-67.4 months), 35 (25%; within IFU 23% vs. outside IFU 35%, p=0.23) patients suffered from endoleaks. The majority were endoleaks type II (n=33), the remaining type Ia (n=5) and type Ib (n=3). No endoleaks type III-V, migrations or aneurysm ruptures occurred. Overall, 19 patients (13%; within IFU 13% vs. 15% outside IFU, p=0.70) received a secondary intervention: nine endoleak related endovascular procedures, three open conversions, two endograft limb related interventions, four surgical revisions of the femoral access sites and two bowl ischemia related procedures, respectively. Conclusions: This non industry-sponsored, multicenter trial indicates that using the TREO device in a real-world setting (both within and outside IFU) seems feasible in the treatment of patients suffering from AAA. While the rate of complications and secondary interventions is in line with previously published data, the findings highlight the fact that standard EVAR is associated with serious adverse events.

Fatal Acute Limb Ischemia Due to Catastrophic Late Endograft Infection and Adjacent Arterial Infection After Endovascular Aneurysm Repair - A Case Report

Introduction

We present a case of late endograft infection that progressed to the left iliac and femoral arteries, leading to left lower extremity gangrene, and the patient's death.

Case

A 65-year-old male with a history of endovascular abdominal aortic aneurysm repair (EVAR) developed left acute limb ischemia (Rutherford category III) and abdominal pain. A CT scan showed significant gas formation around the endograft and complete occlusion of the left distal iliac artery to the femoral arteries. Despite undergoing hip disarticulation and wound care, aortic endograft removal was not possible due to a lack of replacement grafts. Microbiological cultures from arterial pus and urine identified multiple antibiotic-resistant extended-spectrum beta-lactamases (ESBL) producing Escherichia coli. Histopathological analysis of the common femoral artery specimen indicated chronic medium-sized arteritis characterized by endothelial erosion, fibrotic myocytes in the tunica media, and fibrosis of the adventitial layer with inflammatory cell infiltration. The patient succumbed in the ICU 6 days later due to uncontrolled sepsis.

Discussion

Although the incidence of endograft infection after EVAR is low (20-75% morbidity and mortality), it poses significant risks. Sources are often hematogenous, stemming from urinary or respiratory tract infections, and infections extending to subsequent arteries are very rare; they could cause chronic arterial inflammation and, in the long term, may lead to thrombosis and limb ischemia. This case highlights a low-grade infection that emerged 3 months post-procedure. Diagnosis typically involves CT angiography to detect periaortic gas or fluid. Management of high-grade infections necessitates complete endograft removal and graft replacement with infection-resistant options.

Conclusion

Endograft infections after EVAR, while rare, can have severe outcomes. Early diagnosis based on symptoms and CT-Scan. In high-grade infections, endograft removal is the gold-standard therapy, with ongoing follow-up post-EVAR being essential for prevention.

Soluble glycoprotein VI predicts abdominal aortic aneurysm growth rate and is a novel therapeutic target

ABSTRACT

A common feature in patients with abdominal aortic aneurysms (AAAs) is the formation of a nonocclusive intraluminal thrombus (ILT) in regions of aortic dilation. Platelets are known to maintain hemostasis and propagate thrombosis through several redundant activation mechanisms, yet the role of platelet activation in the pathogenesis of AAA-associated ILT is still poorly understood. Thus, we sought to investigate how platelet activation affects the pathogenesis of AAA. Using RNA sequencing, we identified that the platelet-associated transcripts are significantly enriched in the ILT compared with the adjacent aneurysm wall and healthy control aortas. We found that the platelet-specific receptor glycoprotein VI (GPVI) is among the top enriched genes in AAA ILT and is increased on the platelet surface of patients with AAAs. Examination of a specific indicator of platelet activity, soluble GPVI (sGPVI), in 2 independent cohorts of patients with AAAs is highly predictive of an AAA diagnosis and associates more strongly with aneurysm growth rate than D-dimer in humans. Finally, intervention with the anti-GPVI antibody (JAQ1) in mice with established aneurysms blunted the progression of AAA in 2 independent mouse models. In conclusion, we show that the levels of sGPVI in humans can predict a diagnosis of AAA and AAA growth rate, which may be critical in the identification of high-risk patients. We also identify GPVI as a novel platelet-specific AAA therapeutic target, with minimal risk of adverse bleeding complications, for which none currently exists.

Shockwave for peripheral artery disease: an update on trial data

Intravascular lithotripsy (IVL) is fast becoming the vessel preparation tool of choice given its excellent safety profile and associated positive outcomes. In this review, we aim to summarize the most recent trial data as it applies to IVL's utility within the various peripheral arterial beds, including facilitation of large bore vascular access, and elaborate on future directions of this innovative therapy.

Extended aortic coverage in thoracic aortic endovascular repair is not associated with spinal cord ischemia

Objective

Spinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR) remains a debilitating complication, occurring in 10% of patients. Studies have shown that extended aortic coverage is a risk factor for SCI. This study evaluates whether extended aortic length coverage is a significant risk factor for SCI.

Methods

This study retrospectively reviewed 277 consecutive patients who underwent TEVAR successfully between 2006 and 2021 at a single institution. The patients were classified into 2 groups: ≥205 mm and <205 mm of thoracic aortic coverage. Analysis of variance was used to compare these variables and associated aortic coverage between the 2 groups. Univariable logistical regression was used to compare SCI and associated factors.

Results

Of the 269 patients who underwent successful TEVAR, 127 (47.2%) had ≥205 mm and 142 (52.8%) had <205 mm of aorta coverage. Patients with ≥205 mm of thoracic aorta coverage were more likely to be smokers (P < .01) and to have a history of previous stroke (P < .05). Patients with extended coverage were more likely to receive a preoperative lumbar drain (LD) (P < .01). Extended aortic coverage was not associated with a higher risk of SCI compared to standard aortic coverage (4.7% vs 4.2%; P = .84). Extended aortic coverage with or without a preoperative LD did not have an association with SCI (P = .91). Type II endoleaks were seen more in extended aortic coverage (P < .01).

Conclusions

Extended aortic coverage (compared with the standard approach) was not associated with a higher risk of SCI; however, this may have been mitigated by a higher prevalence of prophylactic lumbar drainage in this population.

Safety and Effectiveness of Brachial Artery Preclosure by Purse-String Suture Technique for Left Subclavian Artery Revascularization in Stanford B Aortic Dissection

OBJECTIVES

To assess the safety and efficacy of the combination of brachial artery (BA) cutdown with purse-string suture (PSS) for BA preclosure during fenestrated thoracic endovascular aortic repair (f-TEVAR).

METHODS

We reviewed the consecutive data in our center from January 2022 to May 2023. Clinical data were analyzed retrospectively, including the baseline characteristics, procedural details, complications, and outcomes. Dichotomous data were summarized as absolute values and percentages. Continuous variables were presented as median values and interquartile ranges (IQRs). All patients underwent arterial cutdown with the PSS technique for BA preclosure. The technique was considered successful when complete hemostasis was achieved and confirmed by ultrasonography 24 h postoperatively. The patients were followed up 30 days postoperatively for access-related complications.

RESULTS

Forty-eight patients who underwent f-TEVAR with 48 BA access sites were included [36 males and 12 females; median age: 62 (IQR: 30-78) years]. The median body mass index was 27.3 (IQR: 21.2-32.7) kg/m2. The median access establishing and closing times were 7.8 (IQR: 6-9.3) min and 3.7 (IQR: 2.5-5) min, respectively. The median operative time and length of stay were 75 (IQR: 63-87) min and 7 (IQR: 5-9) days, respectively. Although the success rate was 100%, partial numbness in the median nerve distribution was noted in 1 patient in the forearm. This resolved spontaneously and no permanent neurological problem was seen. No other access-related complications were noted, and the total complication rate was 2.1% (1/48).

CONCLUSIONS

BA preclosure with the PSS technique is safe and effective for left subclavian artery revascularization in Stanford B aortic dissection and can be another option for access closure during f-TEVAR.

A Cadaveric Case Study on the Abdomen: A Temple of Surprises

Femoro-femoral bypass grafts (FFBG) are performed to connect the major vessels of the lower extremities, such as the femoral arteries, to treat patients who have injured or occluded iliac arteries. Typically, patients with multiple comorbidities, such as heart failure, aneurysms, or diabetes, have a significantly higher risk of complications for open, invasive procedures to correct lower limb ischemia. This graft poses as an effective, less invasive option to treat lower-limb ischemia for higher-risk patients. This case study presents a finding of FFBG in an 82-year-old male cadaver during cadaveric dissection in the gross anatomy lab at Geisinger Commonwealth School of Medicine in Scranton, Pennsylvania. Based on the initial findings of cardiomegaly with a triple coronary artery bypass graft (CABG) and pulmonary hypertension in the thoracic cavity and evidence of massive umbilical hernioplasty involving extensive mesh repair, our initial assumption of an FFBG placement in this cadaver was to increase perfusion to lower limbs, circumventing the need for surgical intervention due to the above-mentioned comorbidities, which act as risk factors. However, the discovery of a massive abdominal aortic aneurysm (AAA) measuring 26 cm in circumference with evidence of dissection of its wall and the presence of a stent within the aorta and common iliac arteries placed there as an endovascular aneurysm repair (EVAR) procedure came as a surprise. Publication of such findings provides awareness to curious individuals about the existence of multiple health concerns an individual suffers and how the medical as well as surgical teams work together to provide optimal treatment care to improve their standard of living and prolong their lifespan.

Realistic Aspects of Cardiac Ultrasound in Rats: Practical Tips for Improved Examination

Echocardiography is a reliable and non-invasive method for assessing cardiac structure and function in both clinical and experimental settings, offering valuable insights into disease progression and treatment efficacy. The successful application of echocardiography in murine models of disease has enabled the evaluation of disease severity, drug testing, and continuous monitoring of cardiac function in these animals. However, there is insufficient standardization of echocardiographic measurements for smaller animals. This article aims to address this gap by providing a guide and practical tips for the appropriate acquisition and analysis of echocardiographic parameters in adult rats, which may also be applicable in other small rodents used for scientific purposes, like mice. With advancements in technology, such as ultrahigh-frequency ultrasonic transducers, echocardiography has become a highly sophisticated imaging modality, offering high temporal and spatial resolution imaging, thereby allowing for real-time monitoring of cardiac function throughout the lifespan of small animals. Moreover, it allows the assessment of cardiac complications associated with aging, cancer, diabetes, and obesity, as well as the monitoring of cardiotoxicity induced by therapeutic interventions in preclinical models, providing important information for translational research. Finally, this paper discusses the future directions of cardiac preclinical ultrasound, highlighting the need for continued standardization to advance research and improve clinical outcomes to facilitate early disease detection and the translation of findings into clinical practice.

Towards a reduced order model for EVAR planning and intra-operative navigation

INTRODUCTION

The pre-operative planning and intra-operative navigation of the endovascular aneurysm repair (EVAR) procedure are currently challenged by the aortic deformations that occur due to the insertion of a stiff guidewire. Hence, a fast and accurate predictive tool may help clinicians in the decision-making process and during surgical navigation, potentially reducing the radiations and contrast dose. To this aim, we generated a reduced order model (ROM) trained on parametric finite element simulations of the aortic wall-guidewire interaction.

METHOD

A Design of Experiments (DOE) consisting of 300 scenarios was created spanning over seven parameters. Radial basis functions were used to achieve a morphological parametrization of the aortic geometry. The ROM was built using 200 scenarios for training and the remaining 100 for validation.

RESULTS

The developed ROM estimated the displacement of aortic nodes with a relative error below 5.5% for all the considered validation cases. From a preliminary analysis, the aortic elasticity, the stiffness of the guidewire and the tortuosity of the cannulated iliac artery proved to be the most influential parameters.

CONCLUSIONS

Once built, the ROM provided almost real-time and accurate estimations of the guidewire-induced aortic displacement field, thus potentially being a promising pre- and intra-operative tool for clinicians.

In situ fenestration (ISF) versus single-branched stent graft (SBSG) implantation in the management of acute Stanford type B aortic dissection involving the left subclavian artery

Background

With the advances in medical technology and materials, thoracic endovascular aortic repair has become the mainstay of treatment for aortic dissection. In situ fenestration (ISF) and single-branch stent graft (SBSG) implantation are commonly used methods, with each having its own advantages and disadvantages. The study aimed to compare the perioperative outcomes and one-year follow-up results of patients who underwent ISF or SBSG in the treatment of acute Stanford type B aortic dissection involving the left subclavian artery (LSA).

Methods

From January 2018 to December 2022, consecutive patients with Stanford type B aortic dissection were retrospectively recruited and divided into ISF group and SBSG group according to the type of surgery. The patient's aortic physiology was evaluated by computed tomography angiography at 1, 3, 6, and 12 months after discharge.

Results

This study included 67 patients in the SBSG group and 21 patients in the ISF group. The baseline and preoperative indices were similar between the groups. The success rate of perioperative treatment was 100%, and no adverse consequences occurred in either group. No spinal cord ischemia, stroke, or paraplegia occurred in either group during the one-year follow-up. The rate of endoleak in the SBSG group was significantly lower (3%, all type I endoleaks) than that in the ISF group (9.5% type I and 14.3% type II endoleaks) (P=0.005). Type II endoleak mainly occurred in the LSA. In addition, complete thrombosis of the false lumen was achieved in 95.5% of the SBSG group versus 81.0% of the ISF group, but this was not a significant difference (P=0.091). The maximum diameter of the true lumen increased significantly in the ISF (P<0.001) and SBSG (P<0.001) groups. Meanwhile, the maximum diameter of the false lumen was significantly reduced in the ISF (P<0.001) and SBSG (P<0.001) groups, but the difference in the maximum diameter change of the true or false lumen between the two groups was not statistically significant (P>0.05).

Conclusions

SBSG was associated with a significantly lower incidence of endoleak than was ISF. However, there were no differences observed in complete thrombosis of the false lumen. Further studies with larger sample sizes are needed to definitively establish which treatment is superior in terms of complete thrombosis of the false lumen.

Administration of an antibody against apoptosis inhibitor of macrophage prevents aortic aneurysm progression in mice

Apoptosis inhibitor of macrophage (AIM) is known to induce apoptosis resistance in macrophages and to exacerbate chronic inflammation, leading to arteriosclerosis. The role of AIM in aortic aneurysm (AA) remains unknown. This study examined the effects of an anti-AIM antibody in preventing AA formation and progression. In apolipoprotein E-deficient mice, AA was induced by subcutaneous angiotensin II infusion. Mice were randomly divided into two groups: (i) AIM group; weekly anti-murine AIM monoclonal antibody injection (n = 10), and (ii) IgG group; anti-murine IgG antibody injection as control (n = 14). The AIM group, compared with the IgG group, exhibited reduced AA enlargement (aortic diameter at 4 weeks: 2.1 vs. 2.7 mm, respectively, p = 0.012); decreased loss of elastic lamellae construction; reduced expression levels of IL-6, TNF-α, and MCP-1; decreased numbers of AIM-positive cells and inflammatory M1 macrophages (AIM: 1.4 vs. 8.0%, respectively, p = 0.004; M1 macrophages: 24.5 vs. 55.7%, respectively, p = 0.017); and higher expression of caspase-3 in the aortic wall (22.8 vs. 10.5%, respectively, p = 0.019). Our results suggest that administration of an anti-AIM antibody mitigated AA progression by alleviating inflammation and promoting M1 macrophage apoptosis.

Jejunal ischaemia following inferior mesenteric artery angioembolisation for type 2 endoleak

We present a rare case of short-segment jejunal infarction following inferior mesenteric artery embolisation for type 2 endoleak in a patient who previously underwent endovascular repair of abdominal aortic aneurysm. Potential causes for the event might include thromboembolism or traumatic thrombosis of a jejunal branch of the superior mesenteric artery (SMA) caused by a buddy guide wire used to maintain the position of the long vascular sheath in the SMA hiatus. The condition was recognised on CT and treated with resection of the infarcted segment of the small bowel followed by primary anastomosis.

Vertebral Body Erosions After Glue Embolization of an Aortic Endograft Type II Endoleak: A Case Report

CASE

We present a case of a 66-year-old man with lumbar vertebral body erosions after glue embolization of a Type II endoleak secondary to endovascular repair of an infrarenal aortic aneurysm. Multiple biopsies of the affected vertebrae were culture-negative confirming no evidence of infection. He underwent posterior spinal fusion from L2 to L5 with complete resolution of mechanical low back pain and improved functional outcomes.

CONCLUSION

Vertebral body osseous erosion is a rare complication of aortic endoleak intervention that can be successfully treated with spinal fusion.

Innovation in pathogenesis and management of aortic aneurysm

Aortic aneurysm (AA) refers to the persistent dilatation of the aorta, exceeding three centimeters. Investigating the pathophysiology of this condition is important for its prevention and management, given its responsibility for more than 25000 deaths in the United States. AAs are classified based on their location or morphology. various pathophysiologic pathways including inflammation, the immune system and atherosclerosis have been implicated in its development. Inflammatory markers such as transforming growth factor β, interleukin-1β, tumor necrosis factor-α, matrix metalloproteinase-2 and many more may contribute to this phenomenon. Several genetic disorders such as Marfan syndrome, Ehler-Danlos syndrome and Loeys-Dietz syndrome have also been associated with this disease. Recent years has seen the investigation of novel management of AA, exploring the implication of different immune suppressors, the role of radiation in shrinkage and prevention, as well as minimally invasive and newly hypothesized surgical methods. In this narrative review, we aim to present the new contributing factors involved in pathophysiology of AA. We also highlighted the novel management methods that have demonstrated promising benefits in clinical outcomes of the AA.

Intravascular lithotripsy supported endovascular aneurysm repair

As the use of endovascular aneurysm repair (EVAR) increases, anatomic constraints remain a challenge. In this case report, we describe the use of intravascular lithotripsy to facilitate EVAR in a patient with a severely calcified and stenotic aortic bifurcation. Future applications of intravascular lithotripsy could help expand the use of EVAR to patients with severely stenotic vasculature and optimize outcomes in the treatment of infrarenal abdominal aortic aneurysms.

Outcomes of post-implantation syndrome after endovascular repair for Stanford type B aortic dissection

OBJECTIVE

The aim of this study was to investigate the correlation between post-implantation syndrome (PIS) and long-term prognosis in patients with Stanford type B aortic dissection (TBAD) undergoing thoracic endovascular aortic repair (TEVAR).

METHODS

This retrospective study included 547 consecutive patients diagnosed with TBAD who underwent TEVAR at our institution between January 2014 and December 2019. Patients were categorized into two groups: the PIS group (patients with post-TEVAR PIS) and the non-PIS group (patients without post-TEVAR PIS). In-hospital and follow-up data were analyzed.

RESULTS

The incidence of PIS was 28.9% (158/547 patients). No baseline differences were observed between the PIS (n = 158) and the non-PIS (n = 389) groups. The proportion of emergency surgery in the PIS group was higher than that in the non-PIS group (44.9% vs 26.0%; P < .001), the operation time was longer (median, 65.0; interquartile range [IQR], 56.0-75.0 minutes vs 56.0; IQR, 45.0-66.0 minutes; P < .001), the volume of contrast medium used (median, 65.0; IQR, 56.0-75.0 mL vs 56.0; IQR, 45.0-66.0 mL; P < .001), and the average number of trunk stents (1.85 ± 0.4 vs 1.34 ± 0.5 pieces; P < .001) and branch stents (0.7 ± 0.7 vs 0.2 ± 0.5 pieces; P < .001) used were more in the PIS group than in the non-PIS group. The incidence of supra-aortic branch procedures was higher in the PIS group than in the non-PIS group. There was no significant difference in device-related complications (DRCs) or 30-day mortality between the two groups (2.5% vs 4.4%; P = .442 and 1.3% vs 1.3%; P = .688, respectively). Univariate and multivariable logistic regression analysis showed that emergency surgery, number of trunk stents >1, operation time >58.5 minutes, and contrast medium volume >75 mL were risk factors for PIS, and the odds ratios of emergency operation, number of trunk stents >1 piece, operation time >58.5 minutes, and contrast medium volume >75 mL were 2.526 (95% confidence interval [CI], 1.530-4.173), 4.651 (95% CI, 2.838-7.624), 3.577 (95% CI, 2.201-5.815), and 7.356 (95% CI, 4.111-13.160), respectively. Follow-up was completed in 98.5% (532/540) of the patients, with a median follow-up of 67 months (IQR, 50-86 months). There was no significant difference in survival between the PIS and non-PIS groups (12.4% vs 10.3%; P = .476) during follow-up. The incidences of DRCs (7.8% vs 11.6%; P = .200) and aortic false lumen thrombosis (75.8% vs 79.2%; P = .399) were comparable between the PIS and non-PIS groups. Univariate logistic regression analysis showed that PIS had no effect on long-term follow-up mortality, DRCs, entry flow, or aortic false lumen thrombosis rate.

CONCLUSIONS

PIS is relatively common after TEVAR and emergency surgery; number of trunk stents >1, operation time >58.5 minutes, and contrast medium volume >75 mL are of high predictive value for the assessment of PIS after TEVAR. However, PIS had little effect on early and late postoperative mortality or DRCs.

Individualizing Surveillance after Endovascular Aortic Repair Using a Modular Imaging Algorithm

OBJECTIVES

Surveillance after endovascular aortic repair (EVAR) and fenestrated EVAR (FEVAR) is mainly directed by one-size-fits-all approaches instead of personalized decision making, even though treatment strategies and often endografts themselves are tailor-made to adjust for individual patients. We propose a modular imaging algorithm that escalates surveillance imaging based on invasiveness and need.

MATERIALS AND METHODS

In this retrospective observational study of single-center data, results of a modular imaging algorithm were analyzed. The algorithm is characterized by initiating the examination with standard B-mode then transitioning to Duplex ultrasound, B-Flow, and CEUS. Additional CT(A) studies are conducted where required. The study population included both patients receiving EVAR or FEVAR. A comparative analysis was conducted regarding endoleak detection.

RESULTS

The study population included 28 patients receiving EVAR and 40 patients receiving FEVAR. They accounted for 101 follow-up visits, which led to 431 distinct imaging studies. CEUS has the highest endoleak detection rate, followed by CTA and B-Flow. Duplex ultrasound and B-Flow resulted in 0 and 1 false positive cases, respectively, considering CEUS the reference standard. In a select group of six patients, CEUS was omitted after endoleaks were displayed by Duplex ultrasound or B-Flow, leading to a successful type II coiling and no aneurysm-related adverse events.

CONCLUSIONS

The proposed modular algorithm showed great potential to incorporate principles of personalized medicine in surveillance after endovascular aortic treatment. Since Duplex ultrasound and B-Flow rarely cause false positive endoleaks, more resource-intensive and invasive imaging studies such as CEUS and CTA can be omitted after positive identification.

In-hospital thromboembolic complications after frozen elephant trunk aortic arch repair

OBJECTIVE

This study evaluated the frequency and clinical impact of thromboembolic complications after frozen elephant trunk aortic arch repair using the Thoraflex device (Terumo Aortic).

METHODS

A total of 128 consecutive patients (mean age 67.9 ± 13.7 years, 31.0% female) underwent frozen elephant trunk aortic arch repair using the Thoraflex device between September 2014 and May 2021 in 4 Canadian centers. Patient baseline characteristics, intraoperative details, and frozen elephant trunk thromboembolic complications were collected retrospectively and analyzed.

RESULTS

Fifteen patients (11.7%) had thrombus visualized within the frozen elephant trunk stent graft on imaging (n = 8; 53.3%) or had a thromboembolic event (n = 9; 60.0%) before hospital discharge. Sites of embolism were mesenteric (n = 8; 88.9%), renal (n = 4; 44.4%), and iliofemoral (n = 1; 11.1%). Patients who experienced thromboembolic complications were more likely to have a history of autoimmune disease (n = 3; 20.0% vs n = 2; 1.8%; P = .01) and implantation of a longer frozen elephant trunk stent graft (150 mm vs 100 mm) (n = 13; 86.7% vs n = 45; 39.8%; P < .001). All patients with thromboembolic complications received therapeutic anticoagulation, and a smaller proportion required an open surgical (n = 5; 33.3%) or an endovascular (n = 2; 13.3%) intervention. Radiographic resolution of thromboembolic complications was observed in 86.7% of patients (n = 13). In-hospital mortality occurred in 1 patient, stroke occurred in 1 patient, and transient spinal cord injury occurred in 1 patient.

CONCLUSIONS

Thromboembolic complications occur more often than previously recognized after frozen elephant trunk aortic arch repair using the Thoraflex device and are associated with increased rates of surgical and endovascular reintervention. Prevention and management of these complications require further study.

Delayed Stanford Type A Aortic Dissection After Endovascular Repair of Abdominal Aortic and Common Iliac Artery Aneurysms Resulting in Stent Graft Collapse: A Case Report

We discuss a rare case of Stanford type A aortic dissection (TAAD) occurring several months after endovascular aneurysm repair (EVAR) of the abdominal aortic and the common iliac artery (CIA) aneurysms. The patient underwent urgent surgery for TAAD treatment but died on the table due to intractable bleeding. We conclude that TAAD was likely unrelated to the initial EVAR procedure but rather to atherosclerosis, hypertension, and prior aortic valve replacement. Only a few cases in the literature report TAAD and total collapse of the abdominal aortic stent graft.

The Rise and Fall of Well-Controlled Blood Pressure: Labile Hypertension Following Repair of a Ruptured Abdominal Aortic Aneurysm

Hypertension is a common pathology with several etiologies. If left uncontrolled, severe and even fatal complications can develop, including heart disease, vascular damage, and stroke. Primary hypertension is most commonly seen without an underlying etiology; however, several contributing factors can lead to the development of hypertension. There have been limited cases reporting the effects of an abdominal aortic dissection treated with endovascular aortic repair (EVAR) on the development of labile hypertension. We report a case of uncontrolled, labile hypertension following an EVAR of an abdominal aortic aneurysm in a patient without prior medical history of hypertension.

Open Surgical Conversion After Endovascular Aortic Aneurysm Repair: A Systematic Review and Meta-Analysis

Endovascular aneurysm repair (EVAR) is a preferred treatment for abdominal aortic aneurysms, though it comes with complications such as endoleaks and graft infections that may necessitate late open conversion (LOC). This systematic review and meta-analysis, drawing on studies from PubMed/MEDLINE, Embase, and the Cochrane Database of Systematic Reviews, aimed to evaluate the incidence, outcomes, and factors leading to LOC after EVAR. The analysis of 11 selected studies revealed a 5.3% incidence of LOC, with a patient cohort predominantly male (79%) and an average age of 73.5 years. The interval between initial EVAR and LOC was 35.1 months on average, with the Excluder device most frequently necessitating LOC. A notable 68% of endovascular salvage attempts before LOC failed. The study highlighted rupture and type I endoleak as the primary reasons for urgent LOC, which exhibited a 10-fold higher mortality rate compared to elective LOC. Elective LOC procedures had a 30-day mortality rate similar to primary elective open aneurysm repairs. These findings underscore the importance of vigilant post-EVAR patient monitoring and suggest that the methodological quality of underlying research should be considered in interpreting these results.

Thymidine Phosphorylase Promotes the Formation of Abdominal Aortic Aneurysm in Mice Fed a Western Diet

Aims

The precise molecular drivers of abdominal aortic aneurysm (AAA) remain unclear. Thymidine phosphorylase (TYMP) contributes to increased platelet activation, thrombosis, and inflammation, all of which are key factors in AAA development. Additionally, TYMP suppresses the proliferation of vascular smooth muscle cells (VSMCs), which are central to the development and progression of AAA. We hypothesize that TYMP plays a key role in AAA development.

Methods and Results

We conducted a histological study using human AAA samples and normal abdominal aortas, revealing heightened levels of TYMP in human AAA vessel walls. To validate this observation, we utilized an Ang II perfusion-induced AAA model in wild-type C57BL/6J (WT) and Tymp-/- mice, feeding them a Western diet (TD.88137) starting from 4 weeks of age. We found that Tymp-/- mice were protected from Ang II perfusion-induced AAA formation. Furthermore, by using TYMP-expressing VSMCs as well as primarily cultured VSMCs from WT and Tymp-/- mice, we elucidated the essential role of TYMP in regulating MMP2 expression and activation. TYMP deficiency or inhibition by tipiracil, a selective TYMP inhibitor, led to reduced MMP2 production, release, and activation in VSMCs. Additionally, TYMP was found to promote pro-inflammatory cytokine expression systemically, and its absence attenuates TNF-α-stimulated activation of MMP2 and AKT. By co-culturing VSMCs and platelets, we observed that TYMP-deficient platelets had a reduced inhibitory effect on VSMC proliferation compared to WT platelets. Moreover, TYMP appeared to enhance the expression of activated TGFβ1 in cultured VSMCs in vitro and in human AAA vessel walls in vivo. TYMP also boosted the activation of thrombospondin-1 type 1 repeat domain-enhanced TGFβ1 signaling, resulting in increased connective tissue growth factor production.

Conclusion

Our findings collectively demonstrated that TYMP serves as a novel regulatory force in vascular biology, exerting influence over VSMC functionality and inflammatory responses that promote the development of AAA.

A rare case of an acute type B aortic dissection contained infrarenal rupture of the false lumen after prior endovascular abdominal aneurysm repair

New-onset acute type B aortic dissection after prior endovascular aneurysm repair is extremely rare. Extension of an aortic dissection can cause destabilization of the previously implanted stent graft, thrombosis of the stent graft, and rupture of the aneurysmal sac, with high mortality without therapy. This report describes the case of a 66-year-old patient complaining of sudden abdominal pain radiating to both flanks. Computed tomography angiography of the aorta revealed acute type B aortic dissection with infrarenal rupture of the false lumen after endovascular abdominal aneurysm repair 5 years prior. The patient underwent infrarenal open surgical conversion with suprarenal aortic clamping and implantation of a bifurcated Dacron graft. Postoperatively, no serious complications resulted from the treatment, except for fascial dehiscence. In such cases, the patients can be treated in an emergency situation with open repair, despite the high risk of complications and mortality.

Computational Study of Abdominal Aortic Aneurysm Walls Accounting for Patient-Specific Non-Uniform Intraluminal Thrombus Thickness and Distinct Material Models: A Pre- and Post-Rupture Case

An intraluminal thrombus (ILT) is present in the majority of abdominal aortic aneurysms, playing a crucial role in their growth and rupture. Although most computational studies do not include the ILT, in the present study, this is taken into account, laying out the whole simulation procedure, namely, from computed tomography scans to medical image segmentation, geometry reconstruction, mesh generation, biomaterial modeling, finite element analysis, and post-processing, all carried out in open software. By processing the tomography scans of a patient's aneurysm before and after rupture, digital twins are reconstructed assuming a uniform aortic wall thickness. The ILT and the aortic wall are assigned different biomaterial models; namely, the first is modeled as an isotropic linear elastic material, and the second is modeled as the Mooney-Rivlin hyperelastic material as well as the transversely isotropic hyperelastic Holzapfel-Gasser-Ogden nonlinear material. The implementation of the latter requires the designation of local Cartesian coordinate systems in the aortic wall, suitably oriented in space, for the proper orientation of the collagen fibers. The composite aneurysm geometries (ILT and aortic wall structures) are loaded with normal and hypertensive static intraluminal pressure. Based on the calculated stress and strain distributions, ILT seems to be protecting the aneurysm from a structural point of view, as the highest stresses appear in the thrombus-free areas of the aneurysmal wall.

BMI-Adapted Double Low-Dose Dual-Source Aortic CT for Endoleak Detection after Endovascular Repair: A Prospective Intra-Individual Diagnostic Accuracy Study

PURPOSE

To assess the diagnostic accuracy of BMI-adapted, low-radiation and low-iodine dose, dual-source aortic CT for endoleak detection in non-obese and obese patients following endovascular aortic repair.

METHODS

In this prospective single-center study, patients referred for follow-up CT after endovascular repair with a history of at least one standard triphasic (native, arterial and delayed phase) routine CT protocol were enrolled. Patients were divided into two groups and allocated to a BMI-adapted (group A, BMI < 30 kg/m2; group B, BMI ≥ 30 kg/m2) double low-dose CT (DLCT) protocol comprising single-energy arterial and dual-energy delayed phase series with virtual non-contrast (VNC) reconstructions. An in-patient comparison of the DLCT and routine CT protocol as reference standard was performed regarding differences in diagnostic accuracy, radiation dose, and image quality.

RESULTS

Seventy-five patients were included in the study (mean age 73 ± 8 years, 63 (84%) male). Endoleaks were diagnosed in 20 (26.7%) patients, 11 of 53 (20.8%) in group A and 9 of 22 (40.9%) in group B. Two radiologists achieved an overall diagnostic accuracy of 98.7% and 97.3% for endoleak detection, with 100% in group A and 95.5% and 90.9% in group B. All examinations were diagnostic. The DLCT protocol reduced the effective dose from 10.0 ± 3.6 mSv to 6.1 ± 1.5 mSv (p < 0.001) and the total iodine dose from 31.5 g to 14.5 g in group A and to 17.4 g in group B.

CONCLUSION

Optimized double low-dose dual-source aortic CT with VNC, arterial and delayed phase images demonstrated high diagnostic accuracy for endoleak detection and significant radiation and iodine dose reductions in both obese and non-obese patients compared to the reference standard of triple phase, standard radiation and iodine dose aortic CT.

Rotational Mechanical Thrombectomy to Treat Iliac Limb Occlusion after Endovascular Aortic Aneurysm Repair: The Rotational Mechanical Thrombectomy Italian Study

PURPOSE

To assess the safety and effectiveness of a rotational mechanical atherothrombectomy device in patients with symptomatic iliac limb occlusion after abdominal endovascular aneurysm repair (EVAR).

MATERIALS AND METHODS

A retrospective analysis was conducted on patients who underwent rotational mechanical thrombectomy using the Rotarex S device for symptomatic acute, subacute, or chronic graft limb thrombosis at 5 vascular centers between 2017 and 2021. This study comprised 23 male patients with a mean age of 74.5 years (SD ± 7.2) at the time of the procedure. The clinical presentation of the patients varied, with 1 patient experiencing acute limb ischemia and 11 patients (47.8%) experiencing disabling intermittent claudication. The remaining patients developed chronic limb-threatening ischemia after iliac limb occlusion. Early outcomes included technical success, postprocedural complications, and periprocedural mortality. Follow-up evaluations encompassed primary patency, patient survival, freedom from reintervention, and the need for surgical conversion.

RESULTS

Technical success was achieved in all cases, with no occurrences of distal embolization during or after the procedure, and no periprocedural deaths were reported. Endograft relining was performed in 82.6% of patients to establish a new, nonthrombogenic surface within the graft. Over a median follow-up period of 8 months (interquartile range, 3-16 months), 2 patients experienced iliac limb reocclusion. No deaths or other reinterventions occurred during the observational follow-up period.

CONCLUSIONS

Rotational mechanical thrombectomy for iliac limb occlusion after EVAR appears to be both safe and effective. This technique may uncover intraluminal defects contributing to graft occlusion and enable their resolution within the same procedure.

Ultrasound Particle Image Velocimetry to Investigate Potential Hemodynamic Causes of Limb Thrombosis After Endovascular Aneurysm Repair With the Anaconda Device

PURPOSE

To identify potential hemodynamic predictors for limb thrombosis (LT) following endovascular aneurysm repair with the Anaconda endograft in a patient-specific phantom.

MATERIALS AND METHODS

A thin-walled flow phantom, based on a patient's aortic anatomy and treated with an Anaconda endograft, that presented with a left-sided LT was fabricated. Contrast-enhanced ultrasound particle image velocimetry was performed to quantify time-resolved velocity fields. Measurements were performed in the same phantom with and without the Anaconda endograft, to investigate the impact of the endograft on the local flow fields. Hemodynamic parameters, namely vector complexity (VC) and residence time (RT), were calculated for both iliac arteries.

RESULTS

In both limbs, the vector fields were mostly unidirectional during the peak systolic and end-systolic velocity phases before and after endograft placement. Local vortical structures and complex flow fields were observed at the diastolic and transitional flow phases. The average VC was higher (0.11) in the phantom with endograft, compared to the phantom without endograft (0.05). Notably, in both left and right iliac arteries, the anterior wall regions corresponded to a 2- and 4-fold increase in VC in the phantom with endograft, respectively. RT simulations showed values of 1.3 to 6 seconds in the phantom without endograft. A higher RT (up to 25 seconds) was observed in the phantom with endograft, in which the left iliac artery, with LT in follow-up, showed 2 fluid stasis regions.

CONCLUSION

This in vitro study shows that unfavorable hemodynamics were present mostly in the limb that thrombosed during follow-up, with the highest VC and longest RT. These parameters might be valuable in predicting the occurrence of LT in the future.

CLINICAL IMPACT

This in-vitro study aimed to identify potential hemodynamic predictors for limb thrombosis following EVAR using ultrasound particle image velocimetry (echoPIV) technique. It was shown that unfavorable hemodynamic norms were present mostly in the thrombosed limb. Owing to the in-vivo feasibility of the echoPIV, future efforts should focus on the evaluation of these hemodynamic norms in clinical trials. Thereafter, using echoPIV as a bedside technique in hospitals becomes more promising. Performing echoPIV in pre-op phase may provide valuable insights for surgeons to enhance treatment planning. EchoPIV is also applicable for follow-up sessions to evaluate treatment progress and avoid/predict complications.

Infected aortic endograft with an unusual microbe, Burkholderia cepacia

With the growing use of endovascular aortic repair for aortic aneurysm pathology, multiple cases have been reported of associated endovascular graft infections. Explantation of the infected endograft and the revascularization procedure performed should be individualized with attention to the offending organism. We present the cases of two patients who underwent endovascular aortic repair with the same endograft and developed a graft infection with Burkholderia cepacia, a gram-negative organism with low virulence. Both endografts cultured Burkholderia cepacia complex; however, the organisms were genetically tested and found to be separate, unrelated strains. Both patients underwent successful explantation and revascularization procedures without any surgical-related complications to date.

Computed tomography defined femoral artery plaque composition predicts vascular complications during transcatheter aortic valve implantation

OBJECTIVE

Vascular and bleeding complications after transcatheter aortic valve implantation (TAVI) are common and lead to increased morbidity and mortality. Analysis of plaque at the arterial access site may improve prediction of complications.

METHODS

We investigated the association between demographic and procedural risk factors for Valve Academic Research Consortium (VARC-3) vascular complications in patients undergoing transfemoral TAVI with use of a vascular closure device (ProGlide® or MANTA®) in this retrospective cohort study. The ability of pre-procedure femoral CT angiography to predict complications was investigated including a novel method of quantifying plaque composition of the common femoral artery using plaque maps created with patient specific X-ray attenuation cut-offs.

RESULTS

23 vascular complications occurred in the 299 patients in the study group (7.7%). There were no demographic risk factors associated with vascular complications and no statistical difference between use of closure device (ProGlide® vs MANTA®) and vascular complications. Vascular complications after TAVI were associated with sheath size (OR 1.36, 95% CI 1.08-1.76, P 0.01) and strongly associated with CT-derived necrotic core volume in the common femoral artery of the procedural side (OR 17.49, 95% CI 1.21-226.60, P 0.03).

CONCLUSION

Plaque map analysis of the common femoral artery by CT angiography reveals patients with greater necrotic core are at increased risk of VARC-3 vascular complications.

ADVANCES IN KNOWLEDGE

The novel measurement of necrotic core volume in the common femoral artery on the procedural side by CT analysis was associated with post-TAVI vascular complications, which can be used to highlight increased risk.

DESIGNING PROGRAMMABLE FERROMAGNETIC SOFT METASTRUCTURES FOR MINIMALLY INVASIVE ENDOVASCULAR THERAPY

Minimally invasive endovascular therapy (MIET) is an innovative technique that utilizes percutaneous access and transcatheter implantation of medical devices to treat vascular diseases. However, conventional devices often face limitations such as incomplete or suboptimal treatment, leading to issues like recanalization in brain aneurysms, endoleaks in aortic aneurysms, and paravalvular leaks in cardiac valves. In this study, we introduce a new metastructure design for MIET employing re-entrant honeycomb structures with negative Poisson's ratio (NPR), which are initially designed through topology optimization and subsequently mapped onto a cylindrical surface. Using ferromagnetic soft materials, we developed structures with adjustable mechanical properties called magnetically activated structures (MAS). These magnetically activated structures can change shape under noninvasive magnetic fields, letting them fit against blood vessel walls to fix leaks or movement issues. The soft ferromagnetic materials allow the stent design to be remotely controlled, changed, and rearranged using external magnetic fields. This offers accurate control over stent placement and positioning inside blood vessels. We performed magneto-mechanical simulations to evaluate the proposed design's performance. Experimental tests were conducted on prototype beams to assess their bending and torsional responses to external magnetic fields. The simulation results were compared with experimental data to determine the accuracy of the magneto-mechanical simulation model for ferromagnetic soft materials. After validating the model, it was used to analyze the deformation behavior of the plane matrix and cylindrical structure designs of the Negative Poisson's Ratio (NPR) metamaterial. The results indicate that the plane matrix NPR metamaterial design exhibits concurrent vertical and horizontal expansion when subjected to an external magnetic field. In contrast, the cylindrical structure demonstrates simultaneous axial and radial expansion under the same conditions. The preliminary findings demonstrate the considerable potential and practicality of the proposed methodology in the development of magnetically activated MIET devices, which offer biocompatibility, a diminished risk of adverse reactions, and enhanced therapeutic outcomes. Integrating ferromagnetic soft materials into mechanical metastructures unlocks promising opportunities for designing stents with adjustable mechanical properties, propelling the field towards more sophisticated minimally invasive vascular interventions.

2022 ACC/AHA guideline for the diagnosis and management of aortic disease: A report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

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.

Detection of Endoleaks Following Thoracic and Abdominal Aortic Endovascular Aortic Repair-: A Comparison of Standard and Dynamic 4D-Computed Tomography Angiography

PURPOSE

Endoleaks are a common complication after endovascular aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR). The detection and correct classification of endoleaks is essential for the further treatment of affected patients. However, standard computed tomography angiography (CTA) provides no hemodynamic information on endoleaks, which can result in misclassification in complex cases. The aim of this study was to compare standard CTA (sCTA) with dynamic, dual-energy CTA (dCTA) for detection and classification of endoleaks following EVAR or TEVAR.

MATERIALS AND METHODS

This retrospective evaluation compared 69 sCTA diagnostic examinations performed on 50 different patients with 89 dCTA diagnostic examinations performed on 69 different patients.

RESULTS

In total, 15.9% of sCTA examinations and 49.4% of dCTA examinations led to the detection of endoleaks. With sCTA, 20.0% of patients were diagnosed with endoleaks, while with dCTA, 37.7% of patients were diagnosed with endoleaks. With sCTA, mainly Type 1 endoleaks were detected, whereas, with dCTA, the types of detected endoleaks were more evenly distributed. In comparison with the literature, the frequencies of endoleak types detected with dCTA better reflect the natural distribution than the frequencies detected with standard CTA.

CONCLUSION

Based on the retrospective comparative evaluation, dCTA could pose a valuable supplementary diagnostic tool resulting in a more accurate and realistic detection and classification of suspected endoleaks.