Long Chronic Total Occlusions: Revascularization Strategies

Importance of Using Angiography for the Early Detection of Chronic Limb Ischemia in Diabetic Foot Wounds

Peripheral artery disease (PAD) affects millions of people worldwide, presenting with varying symptom severity, including chronic total occlusion of arteries, and occasionally, limb amputation. There are various interventions, such as atherectomy and the use of drug-coated balloons and stents, which have been developed to revascularize affected ischemic regions. However, each interventional approach must be individualized due to a patient's unique underlying conditions. Comorbid conditions, especially diabetes, play a significant role in PAD, as poorly controlled diabetes can accelerate PAD progression. For this reason, an early and accurate diagnosis of PAD is crucial, especially when symptoms may present dissimilar to classic PAD symptoms, often leading to misdiagnosis. The presented cases highlight the tailored interventions to revascularize arteries in patients with diabetic foot wounds utilizing catheters, stents, guidewires, and balloons, made possible after early angiogram. These interventions have been promising in treating PAD patients, and highlight the need for early diagnosis and timely and customized interventions to prevent limb amputation and mitigate potential complications.

Differences between Lower Extremity Arterial Occlusion vs. Stenosis and Predictors of Successful Endovascular Interventions

Background and Objectives: In patients with peripheral artery disease, there is insufficient understanding of characteristics that predict successful revascularization of the lower extremity (LE) chronic total occlusions (CTOs) and baseline differences in demographic, clinical, and angiographic characteristics in patients with LE CTO vs. non-CTO. We aim to explore these differences and predictors of successful revascularization among CTO patients. Materials and Methods: Two vascular centers enrolled LE-CTO patients who underwent endovascular revascularization. Data on demographics, clinical, angiographic, and interventional characteristics were collected. LE non-CTO arterial stenosis patients were compared. A total of 256 patients with LE revascularization procedures were studied; among them, 120 had CTOs and 136 had LE stenosis but no CTOs. Results: Aspirin use (Odds ratio, OR: 3.43; CI 1.32-8.88; p = 0.011) was a positive predictor whereas a history of malignancy (OR: 0.27; CI 0.09-0.80; p = 0.018) was a negative predictor of successful crossing in the CTO group. The CTO group had a higher history of myocardial infarction (29.2 vs. 18.3%, p = 0.05), end-stage renal disease (19.2 vs. 9.6%, p = 0.03), and chronic limb-threatening ischemia as the reason for revascularization (64.2 vs. 22.8%, p < 0.001). They were more likely to have advanced TransAtlantic Inter-Society Consensus (TASC) stages, multi-vessel revascularization procedures, longer lesions, and urgent treatment. Conclusions: The use of aspirin is a positive predictor whereas a history of malignancy is a negative predictor for successful crossing in CTO lesions. Additionally, LE-CTO patients have a higher incidence of comorbidities, which is expected given their higher disease burden. Successful endovascular re-vascularization can be associated with baseline clinical variables.

Treatment of Difficult, Calcified Lesions: Plaque Modification Strategies

Endovascular management of peripheral arterial disease is continually evolving. Most changes focus on addressing the challenges that hinder optimal patient outcomes; one of the most significant is how to best treat calcified lesions. Hardened plaque results in a variety of technical issues including impaired device delivery, decreased luminal revascularization, poor stent expansion, heightened risk of in-stent stenosis or thrombosis, and increased procedural time and cost. For this reason, plaque modification devices have been developed to mitigate this issue. This paper will describe these strategies and provide the reader with an overview of devices that can be used to treat chronically hardened lesions.

Endovascular revascularization of multi segment chronically occluded ICA

This case report describes a novel endovascular method for treating chronically occluded internal carotid artery (COICA). The patient is a 55-year-old male with vascular risk factors who presented to an outside institution with right-sided weakness and dysarthria, was diagnosed as having a stroke, and discharged with medical management. The patient's symptoms failed to improve throughout the week prompting him to visit another outside institution, where computed tomography (CT) angiography showed bilateral occlusion of the ICAs at their origins extending intracranially. The patient was then transferred to our hospital, where head CT revealed bilateral acute infarcts predominantly in the left centrum ovale/corona radiata and left temporoparietal region. CT perfusion showed a large area of hypoperfusion in the entire left hemisphere as well as part of the right hemisphere (mismatch volume of 438-526 mL). The patient had significant neurological deficits despite sustained high perfusion pressure, so the following morning, the patient was taken for angiography showing complete occlusion of the left ICA with support mostly from the left external carotid artery (ECA)/ophthalmic collateralization. The microcatheter was able to be advanced to the level of the ophthalmic segment of the left ICA, so the decision was made to proceed with stenting from the left ophthalmic ICA to the cervical ICA. Seven consecutive coronary-carotid stents were placed to essentially reconstruct the left ICA. Post-stenting, the patient was treated with an Integrilin drip and transitioned to Aspirin and Brilinta the following morning. The patient's symptoms markedly improved after the procedure. CT perfusion, as well as diffusion magnetic resonance imaging (MRI), revealed recovery of the patient's penumbra and stability of the existing infarcts despite the delayed nature of revascularization respectively. This is a rarely reported study in literature describing the successful deployment of multiple stents in recreating the ICA from its extracranial to intracranial portion.

A method of characterising the complex anatomy of vascular occlusions and 3D printing biomimetic analogues

Chronic total occlusions (CTOs) occur in approximately 40% of individuals with symptomatic peripheral arterial disease and are indicative of critical limb ischaemia. Currently, few medical devices can effectively treat CTOs long-term, with amputation often required. This is due to a lack of knowledge of CTO anatomy, making device design and testing difficult. This study is a proof-of-concept study, which aimed to develop a workflow for further characterising the complex multi-material anatomy of CTOs and creating 3D models of CTO components, which may be useful in producing a vascular CTO biomimetic for device testing. Here, we establish such a workflow using samples of atheromatous plaques. We focus on a high-resolution, non-destructive microcomputed tomography (μCT) technique which enables visualisation of occlusion anatomy at a greater resolution than computed tomography angiography (CTA), which is the typical modality used for CTO clinical visualisation. Four arteries (n = 2 superficial femoral; n = 2 popliteal) with evidence of atheromatous plaques were cut into 8 cm segments, which were then stained with iodine and scanned at low resolution, with calcified regions rescanned at high resolution. Resulting files were manually segmented to generate 3D models, which were then 3D printed in resin using a stereolithography printer to produce parts suitable for creating a biomimetic. In total, μCT files from three arterial segments (n = 2 high resolution, n = 1 low resolution) were deemed suitably calcified for segmentation, and thus were segmented to produce 3D models. 3D models of the arterial wall, intima and atheromatous calcium deposits from a high-resolution popliteal artery scan were successfully 3D printed at several scales. While this research is at an early stage, it holds great promise. The workflow for segmentation and 3D printing various components of an atheromatous plaque established here is replicable and uses software and equipment which are accessible to research laboratories in both academia and industry. The ability to print detailed models on a desktop 3D printer is unprecedented and can be improved further, which is promising for future development of biomimetics with multi-material detail of both soft tissue and calcified components of a vascular occlusion. Indeed, this workflow provides a solid foundation for future studies of CTO anatomy and the creation of true, multi-material CTO biomimetics. Such biomimetics may enable the development of improved interventional devices, as they would mimic the general in vivo CTO environment. As this method cannot be applied in vivo, we cannot yet produce patient-specific biomimetics, however, these analogues would still be important in device development, which would improve patient outcomes in critical limb ischaemia.

Technical perspectives in the management of complex infrainguinal arterial chronic total occlusions

BACKGROUND

The prevalence and incidence of peripheral arterial disease have been increasing in the general population. Although limited data are available on the epidemiology of chronic limb-threatening ischemia, it likely represents <10% of all patients with peripheral arterial disease. In the general population, its overall prevalence has been 0.74%. This specific subgroup of patients can have severe disease presentations. Their symptoms often correlate with a specific infrainguinal morphologic pattern known as chronic total occlusion (CTO). CTO will often be difficult to cross in a standard endovascular fashion. In previous years, several techniques have been developed to overcome the limitations of standard antegrade endoluminal or subintimal approaches, if these approaches fail.

METHODS

We have described the advanced techniques, including subintimal techniques, such as crush balloon, parallel wire, SAFARI (subintimal arterial flossing with antegrade and retrograde intervention), and double-balloon techniques, in detail. Furthermore, we have described a homemade reentry device, which can be used to provide access to the distal true lumen in extreme, uncrossable cases. Retrograde approaches comprise several techniques developed from interventional cardiology techniques. Finally, we have described transcollateral and pedal-plantar loop techniques in detail.

RESULTS

These techniques allow endovascular surgeons to successfully encounter even complex anatomies, which will be present in ∼80% of all CTOs. In the present report, we have reviewed all these advanced techniques, correlated the effectiveness of each with the proximal and distal cap morphologic features, and discussed the economic consequences of the endovascular approach considering the costs vs the disease progression and the materials used during the procedures.

CONCLUSIONS

Effective use of the advanced techniques we have described is of paramount importance because only 20% of patients will have a CTO that is crossable using standard techniques. Thus, the use of these techniques can help endovascular surgeons increase their success for patients with complex anatomic patterns. Furthermore, the possibility of treating these CTOs using only guidewires and catheters will reduce the costs of the procedures. However, their use in clinical practice still must be standardized.

Endovascular Surgery or Both: A Case Report of Hybrid Procedure in a Patient with Abdominal Aortic Aneurysm and Tasc D Aortoiliac Occlusive Disease

Hybrid procedure, a combination of endovascular and open surgical approach, has emerged as the first-line treatment for patients with severe aortoiliac diseases because of its effectiveness. We report a hybrid procedure in a 72 year old man with an Abdominal Aortic Aneurysm (AAA) and Trans-Atlantic Inter-Society Consensus (TASC) D aortoiliac occlusive disease. After two failed attempts using the intraluminal technique (retrograde and antegrade), we successfully performed an endovascular approach with subintimal and Subintimal Arterial Flossing Antegrade-retrograde Intervention (SAFARI) technique with the help of roadmap technology. The vascular surgeon completed the procedure by creating femorofemoral bypass using a Great Saphenous Vein (GSV) graft. The graft was patent and there were no complications at 1 week, 1 month and 6 months follow-up.

Direct occluded vessel puncture technique as a new access site for complex peripheral artery occlusive disease

A 77-year-old male was admitted to our hospital for severe intermittent claudication of both legs. He was diagnosed with aorto-iliac occlusions and a right femoro-popliteal artery occlusion with a diseased common femoral artery by a computed tomography angiography of the lower limb. We planned endovascular therapy for these multi-level occlusive lesions. The aorto-iliac lesion of the left side was antegradely recanalized via the left brachial artery. That of the right side was recanalized retrogradely by a direct occlusive vessel puncture (DOVP) with a dedicated 20 G needle and the Hi-Torque Command 18 ST. After stenting, his symptoms were completely relieved without revascularization of right femoro-popliteal artery, and he was discharged without any complications. The DOVP may also be used as an alternative option when there is not an appropriate approach site. <Learning objective: The appropriate selection of the access site for peripheral artery occlusive disease (PAOD) is one of the most important factors to obtain a successful guidewire recanalization. We occasionally encounter multi-level PAOD without an appropriate access site. The direct occluded vessel puncture should be considered as an alternative option.>.

Feasibility and Safety of the Direct Occluded Vessel Puncture Technique as a New Access Site for Complex Peripheral Artery Occlusive Disease

Aim: This study aims to describe the feasibility and safety of direct occluded vessel puncture as a new access site for complex peripheral artery occlusive disease.

Methods: Eleven consecutive patients with symptomatic peripheral artery disease underwent endovascular therapy using the direct occluded vessel puncture technique. The occluded vessel was punctured using a dedicated 20 G needle and the Hi-Torque Command 18 ST guidewire under duplex echo or fluoroscopic guidance, and a 6 Fr sheath was then inserted. Hemostasis was achieved with the Exoseal^® Vascular Closure Device.

Results: Direct occluded vessel puncture was achieved in 10 of 11 cases (90.9%), and procedural success was achieved in all cases. There were no in-hospital deaths or any complications, including bleeding, pseudoaneurysms, thrombosis, or surgical conversion.

Conclusion: The direct occluded vessel puncture technique using a 20 G needle and the Hi-Torque Command 18 ST is feasible and safe. This technique may also be used as an alternative option when there are no appropriate approach sites.