Retrospective Validation of Global Limb Anatomic Staging System with Respect to Technical Failures in Endovascular Infrainguinal Revascularization for Critical Limb Threatening Ischemia

Introduction: The Global Vascular Guidelines proposed the Global limb anatomic staging system (GLASS) to overcome the shortcomings of previous multiple classification system. It grades the infrainguinal disease into three stages with a specific algorithm to score the femoropopliteal and tibial segments. We aim to retrospectively validate the GLASS staging in primary endovascular therapy with respect to immediate technical failures (ITFs). Materials and Methods: Retrospective data from November 2017 to September 2021 were collected from the existing clinical database. All patients who underwent primary infrainguinal endovascular intervention for critical limb-threatening ischemia were included in the study. The patient who had isolated infrapopliteal disease without a named tibial outflow and only inframalleolar disease were excluded. The GLASS scoring was applied to the angiographic details in the database. The ITFs from the database were compared to the predicted technical failure according to GLASS staging. Statistical analysis was done. Results: Hundred thirty-two patients were studied from clinical database. We had 13 (9.8%) ITFs. None of those in GLASS Stage I had failure. Among 26 patients in Stage II, 1 (4%) had failure, against the predicted failure rate of lesser than 20%. Among 89 patients in GLASS Stage III, only 12 (13.5%) had failures against the predicted failure rate of more than 20%. The majority of failures had occurred in higher GLASS staging. Conclusion: Higher failures in higher GLASS staging have been validated by our study. However, it is limited considering the small cohort and retrospective analysis.