Falsely normalized ankle-brachial index despite the presence of lower-extremity peripheral artery disease: two case reports

Background The ankle-brachial index measurement is used for screening and diagnosis of lower-extremity peripheral artery disease and cardiovascular risk assessment. However, the value is occasionally unreliable since the oscillometric ankle-brachial index can be elevated and falsely normalized despite the presence of lower-extremity peripheral artery disease because of the incompressibility of infrapopliteal arteries at the ankle, potentially leading to a missed diagnosis of lower-extremity peripheral artery disease or underestimation of cardiovascular risk. Case presentation We report two cases of lower extremity peripheral artery disease with normal ankle-brachial index (a 76-year-old Asian man and a 66-year-old Asian man). In both cases, the ankle-brachial index was within the normal range (1.00–1.40) despite the presence of lower-extremity peripheral artery disease, whereas upstroke time at the ankle calculated from the pulse volume waveform simultaneously obtained by plethysmography during the ankle-brachial index measurement was prolonged (≥ 180 milliseconds). Diagnostic imaging tests revealed the presence of occlusive arterial disease in the lower extremity and severe calcification of infrapopliteal arteries. Conclusions In both cases, the oscillometric ankle-brachial index might have been falsely normalized despite the presence of lower-extremity peripheral artery disease because of calcified incompressible infrapopliteal arteries. Sole reliance on the ankle-brachial index value may lead to a missed diagnosis of lower-extremity peripheral artery disease or underestimation of cardiovascular risk. Upstroke time at the ankle was helpful for suspecting the presence of lower-extremity peripheral artery disease in both patients with normal ankle-brachial index. In addition to history-taking and vascular examination, upstroke time at the ankle should be carefully checked for accurate diagnosis of peripheral artery disease and cardiovascular risk assessment in patients with normal ankle-brachial index.

Prospective Study of Serration Angioplasty in the Infrapopliteal Arteries Using the Serranator Device: PRELUDE BTK Study

Purpose: The purpose was to evaluate the safety and efficacy of the Serranator percutaneous transluminal angioplasty serration balloon catheter in patients with infrapopliteal peripheral artery disease. Materials and Methods: A prospective, multicenter, single-arm feasibility study in 46 patients with claudication or chronic limb-threatening ischemia, Rutherford Clinical Category (RCC) 3 to 5, that required treatment of the infrapopliteal arteries above the tibiotalar joint. The primary efficacy outcome was device success—successful insertion, balloon inflation and deflation, and removal of the device(s) with a final diameter stenosis of <50%. The primary safety endpoint was a composite of major adverse limb events (MALE) and perioperative death (POD) through 30 day postprocedure. Other outcomes were change in RCC and ankle-brachial index, wound healing, and clinically-driven target lesion revascularization (CD-TLR). A subset of 9 patients were further evaluated by optical coherence tomography (OCT) or intravascular ultrasound (IVUS) for the presence of serrations in treated lesions. Patient follow-up occurred at 30 days and 6 months. Results: Forty-six patients received treatment with the Serranator device and 55 lesions were treated. Fifty-three lesions were deemed analyzable by the core lab with data and reported hereafter. Device success was 91.7% and freedom from MALE + POD through 30 days was 95.7%. Pretreatment stenosis of 82% was reduced to 21.8% and only 1 lesion (1.9%) required a bailout stent for a grade D dissection. The average maximum balloon inflation pressure was 6 atmospheres. Serrations were present in all treated lesions (n=10) in 9 patients imaged with OCT/IVUS as reviewed by the core laboratory. The RCC score improved by 1 or more level in 70% of patients at 6 months with 42% having a score of 0. The 6 month freedom from CD-TLR was 97.7%. Conclusion: Serranator treatment of infrapopliteal lesions showed excellent lumen gain with minimal evidence of arterial injury and low 6 month CD-TLR. Imaging by IVUS and OCT showed serrations without significant dissection, supporting the device’s proposed mechanism of action.

Endovascular thrombectomy for critical lower limb ischaemia in a patient with COVID-19

Hypercoagulable and proinflammatory states induced by the novel coronavirus (SARS-CoV-2) lead to thrombotic and embolic events. In this case report, the authors describe how they successfully managed acute critical limb ischaemia in a patient of COVID-19 illness with severe pulmonary disease and high thrombus burden in the infrapopliteal arteries.

Intravascular Lithotripsy for Treatment of Calcified Infrapopliteal Lesions: Results from the Disrupt PAD III Observational Study

Purpose: To evaluate the safety and effectiveness of the Shockwave S4 intravascular lithotripsy (IVL) catheter in an “all-comers” cohort of patients with calcified infrapopliteal lesions. Materials and Methods: The Disrupt PAD III Observational Study (NCT02923193) is a prospective, nonrandomized, multicenter single-arm study designed to assess the “real-world” acute safety and effectiveness of the Shockwave Peripheral IVL System for the treatment of de novo calcified, stenotic peripheral arteries. Patients were eligible for enrollment if they had claudication or critical limb ischemia (CLI) and at least moderate calcification as assessed by angiography. This subanalysis includes consecutive patients enrolled with angiographic core lab-assessed treatment of infrapopliteal arteries using the Shockwave S4 IVL catheter. Results From July 2018 to August 2020, 101 patients with 114 calcified infrapopliteal arteries treated with the S4 IVL catheter were enrolled at 15 sites in 3 countries. CLI was present in 69.3% of patients. The anterior tibial and tiboperoneal trunk were the most commonly treated vessels with an overall mean reference vessel diameter (RVD) of 3.1±0.8 mm, minimum lumen diameter (MLD) of 0.5±0.6 mm, and a corresponding diameter stenosis of 83.4%±15.8% by core lab assessment. Mean lesion length was 64.7±54.7 mm with moderate to severe calcification in 69.3% of lesions by the Peripheral Academic Research Consortium (PARC) criteria. Adjunctive calcium-modifying technology, defined as scoring or cutting balloon and/or atherectomy, was used in 22.7% of procedures. The average acute gain at the end of the procedure was 2.0±0.7 mm with a residual stenosis <50% achieved in 99.0% of lesions and a mean residual stenosis of 23.3±12.5%. There were no flow-limiting dissection, embolization, slow flow/no-reflow, or abrupt closure events at the end of the procedure. Conclusion This subanalysis of the PAD III Observational Study represents the largest report to-date of IVL treatment of heavily calcified below-the-knee (BTK) lesions in a “real-world” patient cohort. The use of S4 IVL demonstrated consistent acute safety and effectiveness outcomes consistent with prior IVL peripheral studies. These consistent outcomes were achieved with the initial use of the S4 IVL catheter for treatment of complex BTK lesions.

Mid-term outcomes of an everolimus-eluting bioresorbable vascular scaffold in patients with below-the-knee arterial disease: A pooled analysis of individual patient data

Previous studies on everolimus-eluting bioresorbable vascular scaffolds (BVS) have shown promising 1-year primary patency rates in infrapopliteal arteries. Literature from large cohorts on long-term outcomes with the infrapopliteal Absorb BVS (Abbott Vascular) is lacking. The aim of this study is to pool published and unpublished data to provide a more precise estimate of the 24-month outcomes of Absorb BVS for the treatment of infrapopliteal disease. For the pooled analysis, updated original and newly collected data from three cohorts on treatment with the Absorb BVS for de novo infrapopliteal lesions were combined. The primary endpoint was freedom from restenosis. Secondary endpoints were freedom from clinically driven target lesion revascularization (CD-TLR), major amputation and survival. The pooled analysis included a total of 121 patients with 161 lesions, treated with 189 Absorb BVS in 126 limbs. The mean age of the patients was 73 years, 57% had diabetes mellitus, and 75% were classified as Rutherford–Becker class 5 or 6. Of the 161 lesions, 101 (63%) were calcified and 36 (22%) were occlusions. Successful deployment was achieved with all scaffolds. Freedom from restenosis was 91.7% and 86.6% at 12 and 24 months, respectively, and freedom from CD-TLR was 97.2% and 96.6%. Major amputation occurred in 1.6% of the limbs. Overall survival was 85% at 24 months. In conclusion, this pooled analysis represents the largest reported analysis of mid-term results of the Absorb BVS for the management of chronic limb-threatening ischemia. At 24 months, the Absorb BVS was safe with promising clinical outcomes for the treatment of infrapopliteal disease.

Role of multidetector computed tomography angiography in evaluation of peripheral arterial disease

Background: Diagnostic imaging plays an important role in the evaluation of peripheral arterial disease. Many imaging modalities are available ranging from conventional modalities to the cross-sectional modalities like Doppler ultrasound, DSA, CT and MRI. The main principles of imaging are to characterize the all lesions detected including type of plaques, no. of lesions, length of stenosis, diameter of vessel in pre-stenotic and post-stenotic segments, degree of wall calcification, assisting in pretreatment planning with respect to route of access, selection of balloon and demonstrates size, extent, neck dimention, and presence of thrombosis in cases with aneurysm.Methods: A Cross-sectional observational study was done in 30 patients. Clinically suspected patients of peripheral arterial disease based on history, sign and symptoms and patients diagnosed with peripheral arterial disease on color doppler were included in our study. Both modalities were compared for detecting the occlusion and stenotic segments.Results: A total of 476 vessel segments were imaged by both modalities. When all arterial segments were considered, MDCTA detected stenosis or occlusion lesions in 30% of arterial segments, versus 18.8% compared to DUS. MDCTA showed 9.8% (95% CI:[4.3%, 15.3%]) more lesions than DUS when all arterial segments were considered together, 11.2% (95% CI: [2.7%, 22.1%]) more lesions when only the iliac arteries were compared, 9.1% (95% CI: [3.2%, 17.2%]) more lesions when only the femoropopliteal arteries were compared, 8.9% (95% CI: [1.5%, 16.3%]) more lesions when only infrapopliteal arteries were compared and 13% (95% CI: [2.6%, 25.4%]) more lesions when only the upper limb arterial segments were compared, (p <0.05 for all comparisons).Conclusions: MDCTA may be used as a screening tool in patients with peripheral arterial disease as it is a non-invasive and more accurate modality when compared to DUS and plays important role in management.

Balloon Angioplasty of Infrapopliteal Arteries: A Systematic Review and Proposed Algorithm for Optimal Endovascular Therapy

Endovascular revascularization has been increasingly utilized to treat patients with chronic limb-threatening ischemia (CLTI), particularly atherosclerotic disease in the infrapopliteal arteries. Lesions of the infrapopliteal arteries are the result of 2 different etiologies: medial calcification and intimal atheromatous plaque. Although several devices are available for endovascular treatment of infrapopliteal lesions, balloon angioplasty still comprises the mainstay of therapy due to a lack of purpose-built devices. The mechanism of balloon angioplasty consists of adventitial stretching, medial necrosis, and dissection or plaque fracture. In many cases, the diffuse nature of infrapopliteal disease and plaque complexity may lead to dissection, recoil, and early restenosis. Optimal balloon angioplasty requires careful attention to assessment of vessel calcification, appropriate vessel sizing, and the use of long balloons with prolonged inflation times, as outlined in a treatment algorithm based on this systematic review. Further development of specific devices for this arterial segment are warranted, including devices for preventing recoil (eg, dedicated atherectomy devices), treating dissections (eg, tacks, stents), and preventing neointimal hyperplasia (eg, novel drug delivery techniques and drug-eluting stents). Further understanding of infrapopliteal disease, along with the development of new technologies, will help optimize the durability of endovascular interventions and ultimately improve the limb-related outcomes of patients with CLTI.