SLR - April 2018 - Timothy D. Greene
Pilot Assessment of the Angiosome Concept by Intraoperative Fluorescence Angiography After Tibial Bypass Surgery
Reference: Rother U, Lang W, Horch RE, Ludolph I, Meyer A, Gefeller O, Regus S. Pilot Assessment of the Angiosome Concept by Intraoperative Fluorescence Angiography After Tibial Bypass Surgery. European Journal of Vascular & Endovascular Surgery. 2018 Feb; 55(2):215–221.
Scientific Literature Review
Reviewed By: Timothy D. Greene, DPM
Residency Program: Temple University Hospital, Philadelphia, PA
Podiatric Relevance: The angiosome concept has been described in the foot and ankle by Dr. Attinger et al in cadaveric studies as a way to discuss arterial blood supply to distinct anatomic areas of the foot and ankle. This concept has further been utilized to predict wound healing in patients with primarily ischemic wounds. Conventional wisdom suggests that direct revascularization of the angiosome in which a wound resides would promote the highest likelihood of wound healing. However, this concept has not been fully studied in terms of endovascular and open revascularization techniques. This study aimed to further develop the angiosome concept by demonstrating the effects of tibial bypass revascularization on the microcirculation of the foot using fluorescence angiography.
Methods: Forty patients who underwent tibial bypass surgery were enrolled in this study. Fluorescence angiography was utilized before skin incision as a baseline measurement and then repeated at the conclusion of the procedure (wound closure) to measure changes in the microcirculation as a result of successful tibial bypass.
Results: Quantitative measures of perfusion were recorded as ingress (the maximum measured fluorescence intensity minus the ambient fluorescence intensity) and ingress rate (increase in fluorescence intensity over time, therefore, a parameter of arterial inflow). The perfusion parameters were measured in each of the following angiosomes: 1: Dorsal foot (anterior tibial artery), 2: Plantar-medial foot (medial plantar artery), 3: Plantar-lateral foot (lateral plantar artery), 4: Lateral ankle (peroneal artery). Statistically significant differences arose in the postoperative perfusion characteristics of all angiosomes except the peroneal angiosome, which showed a tendency toward improvement but was not statistically significant. A comparison was then made between the angiosomes that were directly revascularized to the angiosomes that were indirectly revascularized. No statistically significant difference was noted between these groups. However, there was a tendency toward improved microcirculation parameters in the directly revascularized angiosomes of a small subgroup of patients living with diabetes compared to the indirectly revascularized angiosomes, although this difference was not statistically significant. As a secondary outcome measure, wound healing parameters were assessed in the postoperative period. There was no statistically significant difference in wound healing between directly and indirectly revascularized wounds.
Conclusions: Statistically significant improvements in the microcirculatory parameters were evident in the medial plantar, lateral plantar and dorsal foot angiosomes after tibial bypass, regardless of whether the angiosome was revascularized directly or indirectly. These findings can possibly help demonstrate the importance of collateral and retrograde flow to the foot. There was not a statistically significant difference in wound healing between the direct and indirect groups. Fluorescence angiography seems to carry with it the potential of providing a surgical “road map” that provides foot and ankle surgeons with critical information regarding the microvascular circulation of the foot for perioperative management of patients presenting with difficult-to-heal wounds.