Table 5.1.
Key definitions and assumptions in the Global Limb Anatomic Staging System (GLASS)
| Restoration of in-line flow to the ankle and foot is a primary goal. |
| Target arterial path (TAP): the selected continuous route of in-line flow from groin to ankle. The TAP typically involves the least diseased IP artery but may be angiosome based.a |
| Limb-based patency (LBP): maintained patency of the TAP |
| Inflow disease (AI and CFA) is considered separately and assumed corrected when using the infrainguinal staging system for clinical decision-making. |
| Grade within segment is determined by presence of any one of the defined descriptors within that grade (ie, the worst disease attribute within the segment defines grade). |
| Calcification is considered only if severe; increases within segment grade by 1. |
| IM disease (pedal) modifier: describes status of IM vessels (including terminal divisions of the peroneal artery) providing outflow into the foot. |
AI, Aortoiliac; CFA, common femoral artery; IM, inframalleolar; IP, infrapopliteal.
a
The generic case of rest pain is used as a default for defining TAP as the least diseased IP artery, or a specific IP target artery based on clinical circumstances (eg, angiosome directed in setting of wounds) may be selected by the clinician.