Angiosome revascularization improves limb salvage
Because of variations in the arterial anatomy of the foot,5 inconsistencies in the extent of an angiosome and the collateral connections between angiosomes are frequent, suggesting that the angiosome that needs to be revascularized may not be perfused by the predicted artery. This helps explain why technical success may not always equate directly with clinical success, as corroborated by indocyanine green (ICG) imaging and white-light tissue spectrophotometry.6 It is also important to emphasize that in their initial publication, Taylor and Palmer emphasized that the basis of their proposed angiosome concept was on the structural anatomy of the feeder vessel territory. They did not and could not assess the perfusion levels and extent of the feeder vessel with their corresponding choke vessels.
Forefoot procedures, such as trans-metatarsal amputations, frequently interrupt this foot arch. Likewise, a large proportion of patients with renal insufficiency and/or diabetes mellitus present with extensive foot wounds with deep infection that may result in compartmentalization within the foot. In one series, only one third of patients had a single angiosome involved in the tissue loss, 45% of patients had two angiosomes involved and more than 20% of patients had three angiosomes involved.7 Patients with more than one angiosome affected by extensive tissue loss are not easily analyzed using the angiosome-oriented concept and so attempts at classifying the intervention as being direct or indirect is problematic.
Studies analyzing the utility of the angiosome concept need to be careful in analyzing the extent of the territories encompassed by the wounds. More importantly, many interventionalists equate tibial or peroneal revascularization with angiosomal revascularization. This may not be the case if the terminal branches are diseased and pedal loop interventions may still be necessary.
In summary, the angiosome model should not be used as an absolute strategy for interventions on critical limb ischemia patients but should be a guide to assist with a patient-specific strategy for revascularization. Further well-structured prospective studies are needed to assess the value of integrating the interangiosome concept, the status of the pedal arch, and the anatomic-physiologic perfusion angiosome model.
Dr. Sumpio is a professor of surgery and radiology, Yale University, New Haven, Conn.
References
1. J Vasc Surg. 2010 Jun;51:1419-24.
2. J Vasc Surg. 2013 Sep;58:814-26.
3. J Vasc Surg. 2013 May;57:1219-26.
4. J Vasc Surg. 2013 Jan;57:44-9.
5. Am J Surg. 1993 Aug;166:130-5.
