Nellix Device Failure Mechanisms Analysis on Explanted Grafts.

OBJECTIVE: To understand possible reasons for poor durability of the Nellix (Endologix Inc., Irvine, USA) endovascular aneurysm sealing (EVAS) device. MATERIALS AND METHODS: 21 Nellix endoprostheses explanted for endoleaks and migration underwent visual examinations of stent structures and instrumental examinations of the polymer endobags on 4 devices. We harvested 2.0-gram polymer slices out of each of them and tested the samples in an in vitro implantation replication that included wet and dry exposures. During the wet phase, we placed samples in a beaker with saline, mimicking the filling of the endobags during implantation. An exposure to a 37°C environment with 60% humidity during the dry phase replicated the postimplantation conditions inside the aneurysmal sac. RESULTS: Iatrogenic defects affected 16 (76%) metal stents and 20 (95%) endobags. The polymer was disintegrated owing to degradation in 15 (71%) cases. The polymer could lose more than 70% of its initial weight when partially dehydrated and regain 80% when placed in saline. We observed volume decrease and polymer fragmentation during these study phases. CONCLUSIONS: The polymer can lose weight and volume while it dehydrates. This structural degradation of the polymer could lead to the development of endoleaks and/or migration of the device. CLINICAL IMPACT: Based on the results of previous investigations, due to possible endovascular device degradation, patients with endografts should be offered life-long surveillance, and the Nellix device is no exception. Herein we suggest polymer degradation as one of the possible reasons for the device failure. Although Nellix has been withdrawn from the market, there are numerous patients with this type of endograft. Due to its unpredictable performance in the medium and long term, these patients should be recommended enhanced life-long surveillance every 6 months. Any suspicious conditions during the follow-up must be taken seriously and explantation should be considered.

Fundamental Technical Skills of Endovascular Surgery: A Preliminary Study on Its Impact on Skills and Stress during Procedures.

BACKGROUND: Our objective is twofold: determining if simulation allows residents to reach proficient surgeons' performance concerning fundamental technical skills of endovascular surgery (FEVS) while investigating effects of the program on surgeons' stress. METHODS: Using a FEVS training simulator, 8 endovascular FEVS were performed by vascular surgery residents (simulator-naive or simulator-experienced residents [SER]) and seniors. Total time needed to complete the 8 tasks, called total completion time (TCT), was the main evaluation criterion. Analgesia Nociception Index (ANI) was monitored during simulation. Likert scale questionnaire was filled out after each simulation. RESULTS: For each task, TCT was significantly lower for SER and seniors than simulator-naive residents (P = 0.0163). After only 5 simulations, SER were able to reach and even exceed the seniors' level in terms of TCT, with a median time of 10.8 min for SER and 11.9 min for seniors, and wire's movements with a median distance during cannulation of 4.44 m for SER and 4.17 m for seniors. Seniors remained better than SER in terms of precise wire manipulation (wire movement after cannulation), 4.17 m against 4.44 m (3.72-5.96), respectively. Based on the Likert scale stress analysis, seniors felt less stressed than both residents' groups (P = 0.0618). Seniors' initial ANI and mean ANI over the session were significantly lower than those of the residents, P = 0.0358 and P = 0.0250, respectively. CONCLUSIONS: We showed that 5 simulation sessions allowed residents to reach experienced surgeons' capacities on FEVS concerning TCT. Subjectively, seniors felt less stressed than residents, contrary to the results of our objective measures of stress.

Objective Methods to Assess Aorto-Iliac Calcifications: A Systematic Review.

Vascular calcifications in aorto-iliac arteries are emerging as crucial risk factors for cardiovascular diseases (CVDs) with profound clinical implications. This systematic review, following PRISMA guidelines, investigated methodologies for measuring these calcifications and explored their correlation with CVDs and clinical outcomes. Out of 698 publications, 11 studies met the inclusion criteria. In total, 7 studies utilized manual methods, while 4 studies utilized automated technologies, including artificial intelligence and deep learning for image analyses. Age, systolic blood pressure, serum calcium, and lipoprotein(a) levels were found to be independent risk factors for aortic calcification. Mortality from CVDs was correlated with abdominal aorta calcification. Patients requiring reintervention after endovascular recanalization exhibited a significantly higher volume of calcification in their iliac arteries. Conclusions: This review reveals a diverse landscape of measurement methods for aorto-iliac calcifications; however, they lack a standardized reproducibility assessment. Automatic methods employing artificial intelligence appear to offer broader applicability and are less time-consuming. Assessment of calcium scoring could be routinely employed during preoperative workups for risk stratification and detailed surgical planning. Additionally, its correlation with clinical outcomes could be useful in predicting the risk of reinterventions and amputations.

Evolutionary trends and innovations in cardiovascular intervention.

Cardiovascular diseases remain a global health challenge, prompting continuous innovation in medical technology, particularly in Cardiovascular MedTech. This article provides a comprehensive exploration of the transformative landscape of Cardiovascular MedTech in the 21st century, focusing on interventions. The escalating prevalence of cardiovascular diseases and the demand for personalized care drive the evolving landscape, with technologies like wearables and AI reshaping patient-centric healthcare. Wearable devices offer real-time monitoring, enhancing procedural precision and patient outcomes. AI facilitates risk assessment and personalized treatment strategies, revolutionizing intervention precision. Minimally invasive procedures, aided by robotics and novel materials, minimize patient impact and improve outcomes. 3D printing enables patient-specific implants, while regenerative medicine promises cardiac regeneration. Augmented reality headsets empower surgeons during procedures, enhancing precision and awareness. Novel materials and radiation reduction techniques further optimize interventions, prioritizing patient safety. Data security measures ensure patient privacy in the era of connected healthcare. Modern technologies enhance traditional surgeries, refining outcomes. The integration of these innovations promises to shape a healthier future for cardiovascular procedures, emphasizing collaboration and research to maximize their transformative potential.

Intraoperative Staff Radiation Exposure During Aortic Endovascular Procedures.

BACKGROUND: The risk of radiation exposure in the surgical operating room (OR) and/or catheterization laboratory is now well established. Complex endovascular procedures often require multiple approaches and different positioning of the staff members around the patient, potentially increasing the levels of radiations exposure. Our goal was to evaluate the levels of radiation exposure of the members of the staff during endovascular aortic procedures in order to propose radioprotection optimization. METHODS: We included 41 aortic endovascular procedures out of 114 procedures performed between January 12, 2014, and August 31, 2015, including 24 standard endovascular aortic aneurysm repair (EVAR), 7 EVAR with iliac branch (EVARib), 8 complex fenestrated/branched EVAR (F/B EVAR), and 2 thoracic EVAR (TEVAR). Procedures were performed in an OR equipped with a carbon fiber table and a mobile fluoroscopy C-arm. We collected the usual dosimetry data given by the C-arm as well as the patient's peak skin dose (PSD). In all staff members, radiation exposure was measured with thermoluminescent chip dosimeters placed on both temples, on posterior sides of both hands, and on both lower legs. RESULTS: PSD levels were low for EVAR because 24 patients had values below the reading threshold. PSD significantly increased with more complex procedures. Main operator (MO) received the higher level of irradiation on whole body, hands, and ankles. Eye lenses irradiation was higher on both assistant operators (AOs). Other members received low levels of irradiation. We found a high ranges of radiation exposure with a high risk of exposure for the AO, mainly for F/B EVAR and EVARib. CONCLUSIONS: Even if all personal protections are used, staff positioning is a major point that must be considered. If MO is supposed to be the most exposed to X-rays, specific conditions of positioning of the AO may be at risk of exposure.

Targeting Mitochondrial Dynamics during Lower-Limb Ischemia Reperfusion in Young and Old Mice: Effect of Mitochondrial Fission Inhibitor-1 (mDivi-1).

Peripheral arterial disease (PAD) strikes more than 200 million people worldwide and has a severe prognosis by potentially leading to limb amputation and/or death, particularly in older patients. Skeletal muscle mitochondrial dysfunctions and oxidative stress play major roles in this disease in relation with ischemia-reperfusion (IR) cycles. Mitochondrial dynamics through impairment of fission-fusion balance may contribute to skeletal muscle pathophysiology, but no data were reported in the setting of lower-limb IR despite the need for new therapeutic options. We, therefore, investigated the potential protective effect of mitochondrial division inhibitor-1 (mDivi-1; 50 mg/kg) in young (23 weeks) and old (83 weeks) mice submitted to two-hour ischemia followed by two-hour reperfusion on systemic lactate, muscle mitochondrial respiration and calcium retention capacity, and on transcripts specific for oxidative stress and mitochondrial dynamics. At the systemic levels, an IR-related increase in circulating lactate was still major despite mDivi-1 use (+305.9% p < 0.0001, and +269.4% p < 0.0001 in young and old mice, respectively). Further, IR-induced skeletal muscle mitochondrial dysfunctions (more severely impaired mitochondrial respiration in old mice (OXPHOS CI state, -68.2% p < 0.0001 and -84.9% p < 0.0001 in 23- and 83-week mice) and reduced calcium retention capacity (-46.1% p < 0.001 and -48.2% p = 0.09, respectively) were not corrected by mDivi-1 preconditioning, whatever the age. Further, mDivi-1 treatment did not oppose superoxide anion production (+71.4% p < 0.0001 and +37.5% p < 0.05, respectively). At the transcript level, markers of antioxidant enzymes (SOD 1, SOD 2, catalase, and GPx) and fission markers (Drp1, Fis) remained unchanged or tended to be decreased in the ischemic leg. Fusion markers such as mitofusin 1 or 2 decreased significantly after IR in both groups. In conclusion, aging enhanced the deleterious effects or IR on muscle mitochondrial respiration, and in this setting of lower-limb IR, mDivi-1 failed to protect the skeletal muscle both in young and old mice.

What We Know From Reports on Type III Endoleak in the Literature.

Objective: To analyse case reports published on the latest generations of endograft (EG) and understand the mechanisms of type III endoleak (EL) development. Methods: A literature review was undertaken of English language case reports and series that concerned modular junction or component disconnection (type IIIa EL) and fabric perforations (type IIIb EL) after endovascular aneurysm repair. Results: Of the 2 785 studies, 56 full texts were chosen to review 73 cases. Type III EL was diagnosed with computed tomography angiography in 67.1% and digital subtraction angiography in 12.3%; the rest were identified during surgery. Of the 73 EG, 65 (89.0%) were made of polyethylene terephthalate and seven (9.6%) were polytetrafluoroethylene. The type of material was not mentioned in one (1.4%) case report. There were 25 (34.2%) type IIIa and 48 (65.8%) type IIIb EL. The most frequent were trunk-trunk in nine (12.3%) and trunk-limb overlap separations in 14 (19.2%). Type IIIb EL in the trunk area was identified in 27 (37.0%) cases, while 21 (28.8%) defects were found in the limbs. Stent fractures were recognised as an underlying mechanism of type IIIb EL development in one report. A combination of fabric lesions in the trunk and limb area was found in one case. Seven type IIIb EL were related to suture disruption or suture-fabric abrasions. Four cases were related to stent-fabric abrasions, and two developed as a result of fabric fatigue owing to kinking. Information on the mechanisms of degradation was only occasionally and scarcely presented. Given the small number of reports and lack of detailed analysis, no definitive conclusions could be drawn. Conclusion: The available information is scarce and does not allow any definitive conclusions to be drawn on the mechanisms that lead to the development of type III EL. Further explant analyses would be beneficial.

A Tubular Vena Cava Conduit Used to Lengthen a Kidney Transplant Renal Artery Injured During Organ Procurement.

Introduction: Organ transplantation is limited by the supply of transplantable organs, and the supply of organs cannot meet the needs of patients on the waiting list. Ensuring transplantation of any procured organ is therefore mandatory. Organ injury, mostly to the organ's vasculature, can occur during multi-organ procurement, preventing subsequent transplantation. In such a context, vascular reconstructions of arterial or venous organ injuries can be useful. Report: This report describes the case of an obese 64 year old female with a history of diabetic nephropathy who underwent a cadaveric kidney transplant (right kidney with one main renal artery, one inferior polar artery, one vein, and one ureter). The ex situ preparation of the graft revealed that the main renal artery was injured and cut close to the renal hilum (0.8 cm length, 6 mm diameter), not allowing graft implantation. In order to increase the length of the main renal artery, the donor inferior vena cava was used to create a tubular conduit, allowing subsequent graft implantation. Cold and warm ischaemic times were respectively 12 hours and 36 minutes, with immediate graft function. The patient was discharged on day 8 (serum creatinine level was 95 µmol/L). Twelve month follow up was uneventful (serum creatinine level was 108 µmol/L and duplex ultrasonography showed homogeneous blood flow throughout the graft). Discussion: This case report highlights the possibility of overcoming an injured kidney graft artery by creating a tubular vena cava conduit in order to allow subsequent transplantation. Vascular reconstructions of organs injured during procurement should be considered.

Aortobifemoral Bypass in Kidney Transplant Candidates: A Ten-Year Experience.

In patients with severe aorto-iliac calcifications, vascular reconstructions can be performed in order to allow kidney transplantation. The aim of this study was to analyze the outcomes of kidney transplant candidates who underwent an aortobifemoral bypass (ABFB) for aorto-iliac calcifications. A retrospective study including all kidney transplant candidates who underwent an ABFB between 2012 and 2022 was performed. Primary outcome was 30-day morbidity-mortality after ABFB. Secondary outcome was accessibility to kidney transplant waiting list. Twenty-two ABFBs were performed: 10 ABFBs in asymptomatic patients presenting severe aorto-iliac circumferential calcifications without hemodynamic consequences, and 12 ABFBs in symptomatic patients in whom aorto-iliac calcifications were responsible for claudication or critical limb threatening ischemia. Overall 30-day mortality was 0%. Overall 30-day morbidity was 22.7%: 1 femoral hematoma and 1 retroperitoneal hematoma requiring surgical drainage in the asymptomatic group, and 2 digestive ischemia requiring bowel resection and 1 femoral hematoma requiring surgical drainage in the symptomatic group. Among the 22 patients, 20 patients could access to kidney waiting list and 8 patients underwent a kidney transplantation, including 3 living-donor transplantations. Aorto-iliac revascularization can be an option to overcome severe calcifications contraindicating kidney transplantation.

Editor's Choice -- Type IIIb Endoleaks: Fabric Perforations of Explanted New Generation Endoprostheses.

OBJECTIVE: To analyse explanted endografts (EGs) and describe fabric degradation responsible for type IIIb endoleaks. METHODS: As part of the European collaborative retrieval programme, 32 EGs with fabric defects on macroscopic evaluation were selected. The explanted EGs were processed and studied based on the ISO 9001 certified standard protocol. It includes instructions on the collection, transportation, cleaning, and examination of explanted material. The precise analysis was performed with a digital microscope of 20 - 200 times magnification. Possible perforation mechanisms were assessed in stress tests. RESULTS: The median time to explantation of the 32 EGs was 54 months. The explants included 65 separate EG modules, with 46 (70.8%) having a combined 388 fabric perforations. Each EG had a median of 4.79 mm2 (interquartile range [IQR] 9.86 mm2) of cumulated hole area (an average of 0.13% of an EG's area). There were 239 (61.6%) expanded polytetrafluoroethylene (ePTFE; 11 EGs) and 149 (38.4%) polyethylene terephthalate (PET; 21 EGs) fabric ruptures, with no difference in hole distribution between these types of material. Overall, 126 (32.5%) stent related and 262 (67.5%) non-stent related fabric perforations were identified. Perforations caused by fabric fatigue in ePTFE (151, 63.2%) and material kinking in PET (41, 27.5%) were the most common. The stent related perforations were larger in size (0.80 mm2) than non-stent related perforations (0.19 mm2); p < .001. Wider interstent spaces and prolonged implantation duration were associated with an increased risk of stent related perforation development; p < .001 and p = .004, respectively. Large stent related perforations were also detected in the short term, suggesting mechanical issues as underlying causes. CONCLUSION: The fabric of EGs may degrade and lead to the development of perforations. The largest perforations are stent related. Their occurrence and size depend on the implantation time and the EG shape affected by arterial tortuosity. The conclusions are limited to the samples from a select explant group.

Autologous mitochondrial transplantation in male mice as a strategy to prevent deleterious effects of peripheral ischemia-reperfusion.

Ischemia-reperfusion (IR) is known to induce severe tissue damage, notably through mitochondrial dysfunction. Mitochondrial transplantation has emerged as a promising therapeutic strategy in cardiac IR; however, few studies have previously assessed its efficacy in the context of peripheral IR. Therefore, the objective of this study was to assess the effect of mitochondrial transplantation in a hindlimb model of IR injury. Thirty-six SWISS mice were divided into three groups: control (CTL, n = 12), ischemia-reperfusion (IR, n = 12), and IR with mitochondrial transplantation (MT, n = 12). Ischemia (2 h) was induced using the tourniquet model around the right hind limb in the IR and MT groups. In MT group, mitochondria isolated from the right rectus muscle, a nonischemic region, were injected shortly before reperfusion. Mitochondrial respiration, calcium retention capacity, and Western blotting analysis were performed 2 h after reperfusion. Compared with the CTL group, IR led to a decrease in the mitochondrial respiratory capacity, particularly for the basal state (-30%; P = 0.015), oxidative phosphorylation (-36%; P = 0.024), and calcium retention capacity (-45%; P = 0.007). Interestingly, mitochondrial transplantation partially restored these functions since no differences between MT and CTL groups were found. In addition, the administration of healthy mitochondria resulted in a positive regulation of redox balance and mitochondrial dynamics within the skeletal muscle. Although further investigations are needed to better characterize underlying mechanisms, mitochondrial transplantation represents a promising strategy in the setting of IR-induced muscular damage.NEW & NOTEWORTHY Ischemia-reperfusion injury leads to severe muscular damage. Even if prompt revascularization is the treatment of choice, muscular alterations can lead to severe sequalae as mitochondrial dysfunction. Accordingly, adjunctive strategies are needed to overcome the muscular damage. Mitochondrial transplantation has shown beneficial effects in cardiac ischemia-reperfusion, but its role in peripheral muscle is not well established. In this study, we found that mitochondrial transplantation partially restored muscular function when submitted to ischemia reperfusion.

Do Not Forget the Oncovascular: Acute Limb Ischaemia Due to Aortic Epithelioid Angiosarcoma.

Introduction: Aortic epithelioid angiosarcoma (AEA) is a rare malignant tumour and can cause acute limb ischaemia. Report: A 66 year old man was admitted with acute pulmonary oedema due to bilateral renal artery stenosis. An incidental osteolytic left sacral lesion was found on computed tomography angiography, and extensive work up revealed an AEA. Follow up was marked by acute left lower limb ischaemia 13 months later and right chronic limb threatening ischaemia 15 months later. Discussion: Physicians need to consider AEA as an aetiology for acute or chronic limb ischaemia in patients with altered general status but mostly with intra-aortic irregular vegetations without any calcification and parietal involvement on computed tomography angiography.

Calcium in the (Big) Pipes: Intra-TEVAR Calcifications!

Introduction: Calcification of a vascular endograft and adjacent tissues (adventitia, media, and neointima) can result in graft failure. This report shows a rare case of intraluminal calcifications in the distal end of a thoracic endovascular aortic repair (TEVAR) endograft implanted 11 years previously for grade IV blunt traumatic aortic injury (BTAI) in a young patient. Report: A 24 year old man required TEVAR for a BTAI caused by a motorcycle accident. The procedure consisted of TEVAR and an emergency left carotid subclavian venous bypass. Eleven years after the procedure, he had severe hypertension. Intra-TEVAR calcifications appeared, gradually increasing on computed tomography angiography (CTA). Calcifications in the distal luminal end of the TEVAR were responsible for a 60% stenosis on CTA. An open approach was indicated after multidisciplinary discussion, based on the gradient value. The patient underwent explantation, with total replacement of the aortic arch and descending thoracic aorta with re-implantation of the supra-aortic vessels, under extracorporeal circulation. Macroscopic analysis showed no device degeneration but revealed a solid mass at the distal end of the TEVAR. Both microcomputed tomography and histopathology confirmed the calcific nature of the lesions. Conclusion: This case highlights a rare long term graft failure due to calcified neo-atherosclerosis in a TEVAR.

Case Report and Literature Review of Prosthetic Cardiovascular Mucormycosis.

We report a rare case of aorto-bi-iliac prosthetic allograft mucormycosis in a 57-year-old immunocompetent patient in France. Outcome was favorable after surgery and dual antifungal therapy with liposomal amphotericin B and isavuconazole. In a literature review, we identified 12 other cases of prosthetic vascular or heart valve mucormycosis; mortality rate was 38%.

Calcification of Synthetic Vascular Grafts: A Systematic Review.

Objective: Calcification of vascular grafts, including polyethylene terephthalate (PET) and expanded polytetrafluoroethylene (ePTFE) grafts may contribute to graft failure, but is under reported. The aim of this study was to review the literature to assess whether vascular graft calcification is deleterious to vascular graft outcomes. Data sources: The Medline and Embase databases were searched. Review methods: A systematic literature search according to PRISMA Guidelines was performed using a combined search strategy of MeSH terms. The MeSH terms used were "calcification, physiologic", "calcinosis", "vascular grafting", "blood vessel prosthesis", "polyethylene terephthalates", and "polytetrafluoroethylene". Results: The systematic search identified 17 cases of PET graft calcification and 73 cases of ePTFE graft calcification over a 35 year period. All cases of PET graft calcification were reported in grafts explanted for graft failure. The majority of cases of ePTFE graft calcification were unexpectedly noted in grafts used during cardiovascular procedures and subsequently removed. Conclusion: Calcification of synthetic vascular grafts is under reported but can compromise the long term performance of the grafts. More data, including specific analysis of radiological findings as well as explant analysis are needed to obtain a more sensitive and specific analysis of the prevalence and incidence of vascular graft calcification and the impact of calcification on synthetic graft outcomes.