**5.1. Angiography**

A fundamental prerequisite of providing angiosome-directed revascularization is pro‐ found knowledge of the anatomy of the pedal vasculature as well as adequate imaging technique including intraprocedural angiography of both tibial and pedal arteries. Manzi and coworkers have recently reported their experience from more than 2500 antegrade interventional procedures in patients with critical limb ischemia and diabetes [10]. For imaging of the pedal arteries they stress that prolonged filming is often necessary to re‐ cord delayed enhancement of of pedal vessels from retrograde or collateral circulation and that both standard anteroposterior and lateral oblique projections should be ob‐ tained. They have established the following two criteria for correct positioning of the im‐ age intensifier: 1) The base of the fifth metatarsal bone must be seen to project outward from the base of the foot in the lateral oblique view and 2) the first proximal metatarsal interspace must be clearly visualized in the anteroposterior view. These two views tend to give a good overview of the pedal arteries and collaterals.

Recordings of the diabetic feet showed a lower proportion of feet with a "bilateral butterfly pattern" (13.9%), higher proportions of even distribution of temperature (39.1%) and a gen‐ erally more diverse distribution of patterns in the rest. Although interesting, the study did not provide comparisons with angiographic findings that could confirm a correlation be‐ tween the distribution of skin temperature and the distribution of lesions of feed arteries to

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A number of studies have been performed comparing the results of direct revascularization to the relevant angiosome with those of indirect revascularization either through collaterals

In 2009, Neville and coworkers published a retrospective analysis of 43 patients undergoing bypass surgery for tissue loss due to ischemia [12]. Twenty-two were directly revascularized to the relevant agniosome while 21 were indirectly revascularized. Healing occurred in 91% of the directly revascularized patients and only 62% of the indirectly revascularized patients (p=0.03]. Major patient characteristics such as diabetes, tobacco use, and renal failure were evenly distributed between the directly revascularized and indirectly revascularized groups,

On the other hand, Azuma and coworkers [13] reviewed the results of 249 consecutive distal bypasses for critical limb ischemia. 218 limbs were included in the initial analysis which proved significantly lower wound healing rate in the indirect revascularization group than in the direct revascularization group. This was especially the case in a subgroup of patients with end stage renal failure. This finding was, however, compromised by significant base‐ line differences between the groups especially characterized by a higher proportion of pa‐ tients with heel ulcers and gangraene in the indirect revascularization group. After applying propensity scored analysis including only 48 pairs of limbs, the healing rate between the two groups did not reach statistical significance (p=0.185). The authors concluded that the angiosome concept was not relevant for open surgical treatment of critical limb ischemia in patients without end stage renal failure. This conclusion may be questioned in view of the

Iida and coworkers reviewed the results of endovascular treatment of 203 limbs in 177 con‐ secutive patients with critical limb ischemia, Rutherford 5 or 6 [14]. During up to 4 years fol‐ low up, they found significantly higher limb salvage rate in patients with the directly revascularized than indirectly revascularized wounds. Interestingly, the total number of ti‐ bial vessels with run off did not influence the limb salvage rate in neither group, indicating that it is not important how much blood can be provided to the foot but rather whether i t reaches the ischemic area. In a later review by the same group [15], including 369 limbs from 329 consecutive patients, including only patients with isolated below-the-knee lesions, pa‐ tients who had received direct revascularization experienced significantly higher levels of amputation-free survival and freedom from major adverse limb events than patients in

**6. Results from direct versus indirect revascularization**

but wound characteristics and infection were not reported.

limited statistical strength of the propensity scored analysis.

the relevant angiosomes.

or choke vessels.

#### **5.2. Doppler ultrasound**

Attinger and coworkers have described in detail how to map the arterial-arterial connec‐ tions using a Doppler device [7].

As an example, the Doppler signal is located from the posterior tibial artery over the tar‐ sal tunnel. If the signal persists when occluding (by digital compression) the artery dis‐ tally, there is antegrade flow along the posterior tibila artery. If the signal disappears, the flow is retrograde from the anterior tibial artery via the dorsalis pedis and lateral plantar arteries. Similarly, Doppler signal can be obtained from the anterior perforating branch of the peroneal artery in the lateral soft area between the tibia and fibula just above the ankle joint. When the anterior tibial artery is occluded at the takeoff of the lat‐ eral malleolar branch, the Doppler signal will persist if there is antegrade flow along the anterior perforating branch of the peroneal artery. If the Doppler signal disappears, fill‐ ing of the anterior perforating branch must be retrograde from the anterior tibial artery through the lateral malleolar branch. The authors describe how the competence of these connections can have profound significance for the healing potential of an amputation wound.

#### **5.3. Thermography**

Nagase and coworkers [11] reported the results of plantar thermography of skin tempera‐ ture in 129 non-ulcer diabetic patients and 32 normal volunteers. From the pattern of four different plantar angiosomes originally described by Attinger [7], they defined twenty dif‐ ferent patterns of temperature distribution. The most common pattern in normal subjects was a "bilateral butterfly pattern" in which the medial arch showed the highest temperature (46.9%) or an even distribution of temperature across the entire planta of the feet (20.3%). Recordings of the diabetic feet showed a lower proportion of feet with a "bilateral butterfly pattern" (13.9%), higher proportions of even distribution of temperature (39.1%) and a gen‐ erally more diverse distribution of patterns in the rest. Although interesting, the study did not provide comparisons with angiographic findings that could confirm a correlation be‐ tween the distribution of skin temperature and the distribution of lesions of feed arteries to the relevant angiosomes.
