“Global vascular guidelines on the management of chronic limb-threatening ischemia” is an important milestone, but some questions remain

Abstract

We have read with great interest the very much needed and expected guidelines on the management of chronic limb-threatening ischemia (CLTI).1Conte M.S. Bradbury A.W. Kolh P. White J.V. Dick F. Fitridge R. et al.Global vascular guidelines on the management of chronic limb-threatening ischemia.J Vasc Surg. 2019; 69: 3S-125S.e40Abstract Full Text Full Text PDF PubMed Scopus (268) Google Scholar Knowledge on how to serve best the CLTI patients lacked joint expert update and guidelines set forward by the Authors deserve deep appreciation. However, in our opinion, some of the recommendations provided by the authors require further refinement. Our first concern is the way the global limb anatomic staging grade is performed for infrapopliteal (IP) arteries. As the authors rightfully state, in very advanced femoropopliteal disease, some of the patent IP arteries may not become opacified when the dye is injected at the level of proximal arteries. It may be necessary to recanalize the femoropopliteal segment first and inject the dye into the distal popliteal artery to obtain a candid picture of the IP arteries. Accordingly, IP global limb anatomic staging evaluation based on preprocedural angiographic imaging may overestimate the grade and even lead to an erroneous conclusion that the patient is technically unsuitable for any revascularization. Also, some aspects of the presented concept of the IP target artery pathway (TAP) revascularization may be difficult to accept. The article states that the “TAP is generally selected on the basis of the least diseased crural artery providing runoff to the foot.” The fibular artery is often the least affected IP vessel and usually provides some branches to the foot. A guideline might be understood the way that the fibular artery should be preferentially chosen for IP revascularization. Most patients with CLTI, however, feature forefoot ischemic lesions and, in these cases, the hemodynamic effects of fibular artery revascularization will in most instances not equate with tibial artery revascularization. Usually, the diameter of the distal tibial artery is 2.5 mm. The cross-sectional area of a 2.5 mm tube equals almost three 1.5-mm tubes, more than six 1.0-mm tubes, and twenty-five 0.5-mm tubes. Because distal branches of the fibular artery are usually scarce and relatively narrow, even optimal revascularization of the fibular artery might be insufficient to provide sufficient blood flow to the ischemic forefoot. We acknowledge the fact of various approaches to foot revascularization. Additionally, the available evidence is not adequate to back any one of these. We only stress the fact that hemodynamics is essential, and that the number and size of distal fibular branches should be taken into account when choosing the TAP in forefoot lesions. Finally, how should we proceed if we fail to recanalize the IP artery initially chosen to become the IP part of the TAP, but succeed to open another artery and eventually provide sufficient inflow to the foot arteries? It is quite frequent that we are unable to recanalize our first-choice artery, but can recanalize our second or even third choice IP artery, although in our initial assessment we thought they were less suitable for recanalization for being more diseased or with lesions more challenging to cross. Should we then regrade the patient or stick to the primary grade? We think this issue requires additional clarification to obtain comparable results between different centers involved in endovascular revascularization. Global vascular guidelines on the management of chronic limb-threatening ischemiaJournal of Vascular SurgeryVol. 69Issue 6PreviewChronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Full-Text PDF Open ArchiveReplyJournal of Vascular SurgeryVol. 71Issue 1PreviewWe thank the correspondents for their review of the Global Vascular Guidelines document and their thoughtful questions on the application of the new anatomic staging system (Global Limb Anatomic Staging System [GLASS]) proposed for chronic limb-threatening ischemia (CLTI). Indeed, the authors of the guideline acknowledge the need for prospective critical evaluation of the new staging systems (both clinical and anatomic) to improve data comparisons and evidence-based treatment approaches. In the case of GLASS, the key element in this advance is the integration of lesion complexity across the limb from groin to foot, which we believe is central to the selection of an optimal revascularization strategy in CLTI. Full-Text PDF Open Archive