Keywords

Anatomic Classifications

Joint Endovascular and Noninvasive Assessment of Limb Perfusion (JENALI ) Classification

JENALI scoring system divides each tibial vessel (anterior tibial artery, posterior tibial artery, and peroneal artery) into proximal, mid-, and distal segments [1]. The segment is considered patent and assigned a score of 1 if contrast is visualized within the vessel. If the segment is occluded, it is assigned a score of 0. The segment will be considered patent, so long as there is constant contrast line regardless if it fills through direct antegrade flow or indirect retrograde flow. A maximum score of 9 signifies that all the tibial vessels are patent, and a minimum score of 0 signifies that none of the segment is angiographically patent. The strength of the scoring system lies in its simplicity [1].

Angiosomes

In 1987, Dr. Taylor, the anatomist and plastic surgeon, introduced the angiosome concept, separating the body into distinct three-dimensional blocks of tissue fed by source arteries [2]. Angiosomes of the foot are defined by different branches of the three main arteries (Fig. 3.1) [3, 4]. The anterior tibial artery supplies the anterior ankle which turns into the dorsalis pedis and subsequently supplies the dorsum of the foot. The posterior tibial artery supplies the heel through the calcaneal artery, instep through the medial plantar artery, while the lateral plantar artery supplies the lateral midfoot and forefoot. The peroneal artery breaks off into two segments which are the anterior perforating branch which supplies lateral anterior portion of the ankle and calcaneal branch which supplies the plantar portion of the heel .

Fig. 3.1
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Angiosome defined by arterial supply

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TransAtlantic Inter-Society Consensus (TASC ) Document II Classification

The foundations for TASC were laid in 2000 in an attempt to discuss how to treat arterial disease [5]. In an attempt to discuss key aspects of diagnosis and management, update the research, and provide more emphasis on management for the population with diabetes, the TASC group reconvened and updated the guideline in 2007 (TASC II system) [6]. TASC II system has graphically presented and thus is more easily and uniformly applied. Classifications of aortoiliac lesions and femoral-popliteal lesions are summarized in Figs. 3.2 and 3.3, respectively.

Fig. 3.2
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TASC classification of aortoiliac lesions . CIA common iliac artery, EIA external iliac artery, CFA common femoral artery, AAA abdominal aortic aneurysm. From Norgren et al. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II). Journal of Vascular surgery 45:1 Supplement 2007. With permission from Elsevier Science and Technology Journals

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Fig. 3.3
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TASC classification of femoral-popliteal lesions . CFA common femoral artery, SFA superficial femoral artery. From Norgren et al. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II). Journal of Vascular surgery 45:1 Supplement 2007. With permission from Elsevier Science and Technology Journals. For the tibial lesions, the unshaded region is the target stenosis/occlusion. The artery within the shaded rectangle is the associated, “background,” disease. Permission granted from Wiley

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Endovascular therapy is the treatment of choice for type A lesions, and surgery is the treatment of choice for type D lesions. Endovascular treatment is the preferred treatment for type B lesions, and surgery is the preferred treatment for good-risk type C lesions. The patient’s comorbidities, the fully informed patient preference, and the local operators’ long-term success rates must be considered when making treatment recommendations for TASC B and C lesions .

Symptom Classifications

Critical limb ischemia (CLI ) is a manifestation of peripheral artery disease that describes patients with typical chronic ischemic pain [6]. The Rutherford and Fontaine symptom classification systems are the most widely used [7, 8]. The walking distance that defines mild, moderate, and severe claudication is not specified in the Rutherford classification but is part of the Fontaine classification.

Rutherford Classification

Grade 0

Category 0: Asymptomatic

Category 1: Mild claudication

Grade I

Category 2: Moderate Claudication

Category 3: Severe Claudication

Grade II

Category 4: Rest pain

Grade III

Category 5: Ischemic ulceration not exceeding ulcer of the digits of the foot

Category 6: Severe ischemic ulcers or frank gangrene

Fontaine Classification

Stage 1: No symptoms

Stage 2: Intermittent claudication subdivided into:

Stage 2a: Claudication at a distance greater than 200 m

Stage 3b: Claudication at a distance less than 200 m

Stage 3: Nocturnal and/or rest pain

Stage 4: Tissue necrosis and/or gangrene in the limb

Wound, Ischemia, and Foot Infection (WIfI ) Classification

Rutherford and Fontaine classifications are based on symptom severity from perfusion. However, perfusion is only one determinant of outcome. Wound extent and the presence and severity of infection also greatly impact the threat to a limb. Therefore, a new classification was implemented by the Society for Vascular Surgery Lower Extremity Guidelines Committee [9]. The estimated risk of amputation of each stage is summarized in Fig. 3.4.

Fig. 3.4
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Risk/benefit : clinical stages by expert consensus . IDSA Infectious Diseases Society of America, PAD peripheral artery disease, PEDIS perfusion, extent/size, depth/tissue loss, infection, sensation, UT University of Texas. From Mills et al. Society for Vascular Surgery Document J. Vasc Surg 2014;59:220–34. With permission from Elsevier Science and Technology Journals

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Wound

Grade 0: Rest pain; no wound, no ulcer, no gangrene

Grade 1: Small shallow ulcer(s) on the distal leg or foot, any exposed bone is only limited to distal phalanx (i.e., minor tissue loss: limb salvage possible with simple digital amputation [one or two digits] or skin coverage)

Grade 2: Deeper ulcer on distal leg or foot with exposed bone, joint, or tendon or shallow heel ulcer without involvement of the calcaneus (i.e., major tissue loss: salvageable with >3 digital amputations or standard transmetatarsal amputation plus skin coverage)

Grade 3: Extensive deep ulcer of the forefoot and/or midfoot or full-thickness heel ulcer with or without involvement of the calcaneus (i.e., extensive tissue loss: salvageable only with complex foot reconstruction or nontraditional TMA [e.g., Chopart or Lifranc amputation])

Ischemia

Grade 0: ABI ≥ 0.8, ankle systolic pressure > 100 mmHg, toe pressure (TP)/transcutaneous oxygen (TcPO2) ≥ 60

Grade 1: ABI 0.6–0.79, ankle systolic pressure 70–100 mmHg, TP/TcPO2 40–59

Grade 2: ABI 0.4–0.59, ankle systolic pressure 50–70 mmHg, TP/TcPO2 30–49

Grade 3: ABI ≤ 0.39, ankle systolic pressure <50 mmHg, TP/TcPO2 < 30

Foot Infection

Grade 0: No symptoms or signs of infection

Grade 1: Infection is present and at least two of the following are present: local swelling or induration, erythema >0.5 to ≤2 cm around ulcer, local tenderness or pain, local warmth, or purulent discharge. Other causes of inflammatory response of the skin have been excluded

Grade 2: Local infection is present as defined for Grade 1, but extends >2 cm around ulcer, or involves the structures deeper than the skin and subcutaneous tissues (e.g., abscess, osteomyelitis, septic arthritis, fasciitis). No clinical signs of systemic inflammatory response

Grade 3: Local infection is present as defined for Grade 2, but clinical signs of systemic inflammatory response are present as manifested by two or more of the following: temperature >38 °C or <36 °C; heart rate >90 beats per minute, respiratory rate >20 breaths per minute or PaCO2 < 32 mmHg; white blood cell count >12,000 or <4000 (cu/mm) or >10 % immature band forms present

Wagner Ulcer Classification System

Grade 1: Superficial diabetic ulcer

Grade 2: Ulcer extension involving the ligament, tendon, joint capsule, or fascia with no abscess or osteomyelitis

Grade 3: Deep ulcer with abscess or osteomyelitis

Grade 4: Gangrene to the portion of the forefoot

Grade 5: Extensive gangrene of the foot

Peripheral Academic Research Consortium (PARC ) Classification

The goal of the PARC group was to develop standardized definitions for patients with lower extremity PAD allowing for clinical characterization and evaluation of therapies on the basis of imaging or clinical outcomes [10]. The Fontaine and Rutherford classifications were modified to use descriptive, rather than numeric, terms to classify the severity of PAD limb symptoms (Table 3.1). The limitation of current Rutherford classification system in part was felt to be due to the changing demographics of critical limb ischemia (CLI) patients with increased rates of diabetes and renal disease. PARC has also presented hemodynamic definition for CLI patients in the same article (Table 3.2).

Table 3.1 Proposed clinical symptom classification by PARC grou p
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Table 3.2 Hemodynamic definitions of critical limb ischemia
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ORC Classification

Finally, in an effort to combine anatomy, physiology, and patient comorbidities, the “ORC” scheme, initially proposed by Dr. Raymond Dieter, Jr. for oncological surgery: “O” is for operability (from a physiological stress standpoint (including renal function), which is best for patient—open surgery or endovascular therapy); “R” is for resectability, but here it would indicate the ability to revascularize either with open bypass (conduits/distal, vasculature/infection, etc.) or perform endovascular therapy; and “C” is for curability (if the patient has life-threatening gangrene or an ulceration that ultimately will never heal, then amputation rather than revascularization may be preferred). Table 3.3 summarizes ORC classification modified for CLI treatment .

Table 3.3 ORC classifications modified for CLI treatment
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