SVS Launches Mobile Apps for Staging of Chronic Limb-Threatening Ischemia

January 18, 2021—The Society for Vascular Surgery (SVS) recently introduced three new mobile apps to guide physicians in the treatment and management of chronic limb-threatening ischemia (CLTI) that can be downloaded online at the Apple App store.

The apps are available on the SVS interactive practice guideline (iPG) mobile platform, which delivers evidence-based SVS clinical practice guidelines in one single app containing guideline recommendations, clinical calculators, and access to the full-text guidelines. The apps require iOS 11.0 or later and is compatible with iPhone and iPad.

The latest apps help facilitate translating the Global Vascular Guidelines on managing CLTI. The guidelines, edited by Michael S. Conte, MD, Andrew W. Bradbury, MD, and Philippe Kolh, MD, et al were published in 2019 as a joint effort of the SVS (Journal of Vascular Surgery [2019;69:3S-125S]), the European Society for Vascular Surgery (European Journal of Vascular and Endovascular Surgery [2019;58:S1-S109]), and the World Federation of Vascular Societies.

“The SVS is excited to offer these new tools for all practicing vascular specialists who care for patients with CLTI,” commented Dr. Conte, SVS editor for the Global Vascular Guidelines, in the SVS announcement. “Broad dissemination and use of these calculators will increase the quality of patient and provider discussions about prognosis and treatment, provide opportunity for validation and future refinement of the tools, and promote evidence-based care for patients with this challenging disease.”

According to SVS, these guidelines highlight the importance of individualized clinical decision-making based on the assessment of PLAN: patient risk, limb severity, and anatomic pattern of disease. PLAN provides an organized framework for provider-patient discussions as well as outcomes assessment and evidence-based practice.

SVS advised that the three new apps feature calculators that are simple to use and meant for everyday practice settings. The apps allow for (1) real-time estimation of patient risk; (2) severity of limb threat; and (3) anatomic complexity of disease:

1. The VQI CLTI Mortality Prediction Model was developed from a cohort of 38,470 unique patients who underwent infrainguinal revascularization (open or endovascular) for CLTI and had data available in the Vascular Quality Initiative registry. Using baseline patient demographics, comorbidity, ambulatory status, and medication use this model estimates both 30-day (periprocedural) and 2-year patient survival. Risk groups are summarized as low (> 97% 30-day and > 70% 2-year survival), medium (95%-97% 30-day, 50%-70% 2-year survival), or high (< 95% 30-day or < 50% 2-year survival).
2. The SVS Threatened Limb Classification [WIfI] calculator uses the consensus scheme for estimating the risk of major amputation that has since been validated across multiple institutional studies and registries. The target population for WIfI staging is any patient referred for possible CLTI, excluding those with purely venous or traumatic wounds, acute limb ischemia, embolic or nonatherosclerotic disease. Wound, ischemia, and infection are each graded on a 0 to 3 scale. The combination of grades is then grouped into four clinical stages based on the estimated 1-year risk for major amputation. WIfI staging is recommended for all patients at initial presentation, and over time to monitor response to interventions or disease progression.
3. The Global Limb Anatomic Staging System [GLASS] calculator allows the treating vascular specialist to estimate the complexity of infra-inguinal arterial disease from an angiogram. A high-quality study including the ankle and foot is required. The treating physician first decides on the preferred Target Artery Path (TAP), which is the primary infrapopliteal artery selected for establishing in-line flow for the case at hand. Grades are then defined for the femoropopliteal and infra-popliteal segments based on lesion location, length, and severity. These grades are then combined into three overall GLASS Stages for the limb that corresponds to low-, intermediate-, and high-complexity disease. These disease patterns are expected to correlate with both immediate technical success and 1-year limb-based patency for an endovascular approach.

The SVS IPG app includes the following guidelines:

• Global Vascular Guidelines on Chronic Limb-Threatening Ischemia (2019)
• SVS Follow-up After Arterial Procedures (2018)
• SVS Abdominal Aortic Aneurysm (2018 update)
• SVS Lower Limb PAD - Asympt. & Claudication (2015)
• SVS/AVF Venous Leg Ulcers (2014)
• SVS Threatened Lower Limb (WIfI) (2014)
• SVS/AVF Acute DVT (2012)
• SVS Carotid Disease Update (2011)
• SVS/AVF Varicose Veins & CVI (2011)
• SVS Thoracic Aortic Trauma (2011)
• SVS L. Subclavian Artery & TEVAR (2009)
• SVS AV Hemodialysis Access (2008)