Role of the Global Limb Anatomic Staging System in predicting outcomes of chronic limb-threatening ischemia in patients treated by drug-coated balloons

Background

The Global Limb Anatomic Staging System (GLASS) was proposed to assess the procedural complexity and technical failure rate and stratify the anatomic pattern of chronic limb-threatening ischemia (CLTI). However, more evidence is needed to validate the GLASS in staging outcomes after endovascular therapy in patients with CLTI treated with drug-coated balloons (DCBs). This study aims to evaluate the role of the GLASS in predicting outcomes of CLTI patients treated with DCBs.

Methods

This multicenter, retrospective cohort study enrolled patients with CLTI treated with DCBs from July 2016 to June 2019. GLASS stages were assigned for every limb. The limb-based patency (LBP) rate, clinically driven target lesion revascularization (CD-TLR) rate, clinical improvement, and safety endpoints were analyzed and compared across the GLASS stages over 12 months of follow-up. Risk factors for the loss of LBP were identified using Cox regression analysis.

Results

A total of 90 limbs were enrolled, with 55 (61.1%) having isolated femoropopliteal lesions and 35 (38.9%) having femoropopliteal and infrapopliteal lesions. Of the limbs, 17 (18.9%), 12 (13.3%), and 61 (67.8%) were assigned to GLASS stages I, II, and III, respectively. The Kaplan-Meier estimate of the 12-month LBP was 65.4%, and no difference was found among the different stages (stage I 81.1%; stage II 85.2%; stage III 54.4%; P=0.080). The LBP was lower in stage III than in stages I and II combined (stage I and II 83.5%; stage III 54.4%; P=0.027). Similar results were found for the freedom from CD-TLR rates among the different stages. The ankle-brachial index values improved from 0.42±0.29 to 0.78±0.35 at follow-up (P<0.001). The rates of mortality, any amputation, and major amputation were similar among the groups. GLASS stage III and coronary heart disease were identified as independent risk factors for the loss of LBP at 12 months.

Conclusions

The 1-year LBP and freedom from CD-TLR rates were lower in GLASS stage III than in stages I and II. The GLASS classification could predict the outcomes of CLTI patients with femoropopliteal lesions treated with DCB.

The Infrapopliteal Global Limb Anatomic Staging System Predicts Wound Healing and Pain Relief After Partial Revascularization

OBJECTIVE

Chronic limb-threatening ischemia is frequently associated with crural artery occlusion. Complete revascularization beyond the diseased crural artery is preferable; however, complete revascularization is challenging in many cases for various reasons. On the other hand, partial reconstruction for inflow disease sometimes leads to complete relief of symptoms. It is not elucidated which patients may recover from chronic limb-threatening ischemia with partial revascularization. Therefore, we aimed to evaluate the factors affecting outcomes after partial revascularization.

METHODS

We retrospectively reviewed the medical records of patients who underwent first-attempt partial revascularization, for chronic limb-threatening ischemia, for limb salvage, in our institution, between April 2012 and December 2020. We divided these 103 cases into two groups: the salvage group (who achieved wound healing or relief from rest pain with partial revascularization; n=81) and the non-salvage group (who ended with major amputation or additional distal revascularization; n=22). We evaluated the factors affecting the outcome of partial revascularization in terms of patient risk, limb severity (SVS Lower Extremity Threatened Limb Classification System; WIfI classification), and anatomical pattern (Global Limb Anatomic Staging System; GLASS classification).

RESULTS

Although patient risk between the two groups was not statistically significant, hypoalbuminemia (<3.0 mg/dl) was more prevalent in the non-salvage group without significance (P = 0.068). Regarding limb severity status, there was no significant difference in WIfI grades. Wound grade showed the strongest correlation (P = 0.11) and reduced wound grade suggested future wound healing. In terms of GLASS, infrapopliteal grade was statistically significant (P = 0.033). Upon multivariate analysis, among infrapopliteal grade, hypoalbuminemia and wound grade, infrapopliteal grade (P = 0.0096) and hypoalbuminemia (P = 0.2512) revealed significant differences. Wound grade also showed correlation (P = 0.085).

CONCLUSION

The usefulness of the WIfI classification and GLASS classification to predict wound healing after partial revascularization for chronic limb-threatening ischemia was validated.

Validation of the GLASS Staging Systems in Patients With Chronic Limb-Threatening Ischemia Undergoing De Novo Infrainguinal Revascularization

OBJECTIVES

The Global Limb Anatomic Staging System (GLASS) was proposed for evaluating the anatomic complexity of arterial disease in patients with chronic limb-threatening ischemia (CLTI). We aimed to examine the relationship between GLASS stage and treatment outcomes after infrainguinal revascularization in patients with CLTI.

METHODS

We retrospectively analyzed data of patients undergoing infrainguinal revascularization for CLTI between 2010 and 2018 to examine whether GLASS stage affects the limb salvage, wound healing, and overall survival (OS).

RESULTS

Throughout the study period, 153 CLTI patients and 190 limbs with Fontaine classification III and IV were analyzed for major amputation and OS, and 125 patients and 157 limbs of Fontaine classification IV were analyzed for wound healing. The number of patients with WIfI stage 1, 2, 3, and 4 was 14 (7.4%), 44 (23.2%), 65 (34.2%), and 67 (53.3%), respectively. The number of patients with GLASS stage I, II, and III was 23 (12.1%), 48 (25.3%), and 119 (62.6%), respectively. Among the 190 limbs, the number subject to bypass surgery, endovascular therapy, and hybrid therapy was 132 (69.5%), 39 (20.5%), and 19 (10.0%), respectively. A multivariate analysis showed that only WIfI stage and inframalleolar (IM) disease were risk factors for major amputation and impaired wound healing. There was no relationship between GLASS stage and limb salvage or wound healing. A multivariate analysis revealed that age, geriatric nutritional risk index and GLASS stage were risk factors for 2-year OS (P < 0.01). Patients with all risk factors had a poor prognosis (35.3% at 2 years).

CONCLUSION

WIfI stage and IM disease predicted limb salvage and wound healing after infrainguinal revascularization in patients with CLTI. Although GLASS stage did not affect limb salvage or wound healing, it was a prognostic factor for poor OS. The GLASS staging could be useful for deciding between bypass surgery and endovascular therapy in prediction of prognosis.

Does the Global Limb Anatomic Staging System Inframalleolar Modifier Influence Long Term Outcomes of Chronic Limb Threatening Ischaemia after Distal Bypass?

OBJECTIVE

The purpose of this study was to evaluate the influence of inframalleolar disease (Global Limb Anatomic Staging System Inframalleolar [GLASS IM] modifier) on long term outcomes of patients with chronic limb threatening ischaemia (CLTI) after distal bypass.

METHODS

Patients who underwent distal bypass for CLTI from January 2012 to December 2019 at a single centre were reviewed retrospectively. Comparisons including baseline characteristics, procedural details, and long term outcomes were made between patients with an intact pedal arch (GLASS IM modifier P0), an absent or severely diseased pedal arch (P1), and no target artery crossing the ankle into the foot (P2), diagnosed by pre- and intra-operative high quality angiography. The primary endpoint was limb salvage. The secondary endpoints were graft patency and wound healing.

RESULTS

A total of 254 distal bypasses were performed in 206 patients (139 males; median age, 76 years). The GLASS IM modifier was P0 in 80 (32%) limbs, P1 in 127 (50%), and P2 in 47 (18%). During the follow up period, 22 limbs (9%) required major amputation. The limb salvage rates at three years in P0, P1, and P2 cases were 94%, 89%, and 93%, respectively, with no significant differences among the modifiers. The primary patencies at three years in P0, P1, and P2 cases were 49%, 38% and 24%, respectively. The primary patency in P2 cases was significantly lower than that in P0 cases (p < .050). The respective wound healing rates at 12 months were 97%, 93%, and 79%, and again the wound healing rate in P2 cases was significantly lower than those in other cases (p < .050).

CONCLUSION

Long term outcomes including patency, limb salvage, and wound healing after distal bypass for CLTI patients with an infrapopliteal lesion were acceptable in cases in each GLASS IM modifier.