Does the Global Limb Anatomic Staging System Inframalleolar Modifier Influence Long Term Outcomes of Chronic Limb Threatening Ischaemia after Distal Bypass?
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Published on: September 22, 2020
Taira Kobayashi1, Masaki Hamamoto1, Takanobu Okazaki1
1Department of Cardiovascular Surgery, JA Hiroshima General Hospital, Hatsukaichi-shi, Japan.
Insights
The Global Limb Anatomic Staging System Inframalleolar (GLASS IM) modifier impacts long-term outcomes for chronic limb-threatening ischemia (CLTI) patients undergoing distal bypass. While limb salvage remains high across all GLASS IM categories, patency and wound healing are notably lower in P2 cases.
Area of Science:
- Vascular Surgery
- Interventional Cardiology
- Limb Revascularization
Background:
- Chronic limb-threatening ischemia (CLTI) poses a significant risk of amputation.
- Distal bypass surgery is a key revascularization strategy for CLTI.
- The Global Limb Anatomic Staging System Inframalleolar (GLASS IM) modifier stratifies disease severity in the inframalleolar region.
Purpose of the Study:
- To assess the impact of the GLASS IM modifier on long-term outcomes after distal bypass in CLTI patients.
- To compare limb salvage, graft patency, and wound healing rates across different GLASS IM categories (P0, P1, P2).
Main Methods:
- Retrospective review of 254 distal bypass procedures in 206 CLTI patients (2012-2019).
- Patients were classified into GLASS IM groups: P0 (intact pedal arch), P1 (absent/severely diseased pedal arch), and P2 (no target artery crossing the ankle).
- High-quality pre- and intra-operative angiography was used for classification. Primary endpoint: limb salvage; secondary endpoints: graft patency and wound healing.
Main Results:
- Limb salvage rates at 3 years were high across all groups (P0: 94%, P1: 89%, P2: 93%) with no significant differences.
- Three-year primary patency rates varied: P0 (49%), P1 (38%), and P2 (24%), with significantly lower patency in P2 vs. P0.
- Twelve-month wound healing rates were 97% (P0), 93% (P1), and 79% (P2), with significantly lower rates in P2.
Conclusions:
- Distal bypass for CLTI patients demonstrates acceptable long-term outcomes across all GLASS IM modifiers.
- However, the P2 modifier (no target artery crossing the ankle) is associated with significantly reduced graft patency and wound healing.
- These findings highlight the importance of the GLASS IM classification in predicting specific outcomes beyond limb salvage.
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.
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