1 General This book describes treatment methods that are used in the vast majority of cases of patients with peripheral arterial occlusive disease. It is not the task of this book to discuss this disease entity in its various manifestations. This chapter is a brief review of what the physician must be aware of when examining and treating a patient with peripheral arterial occlusive disease. Peripheral arterial occlusive disease is in most cases a degenerative disorder that increases in severity with age and is promoted by various risk factors. Risk factors: • Age • Smoking • Diabetes • Hypertension • Hyperlipidemia • Sedentary lifestyle Every invasive therapy must therefore include consultation with the patient about how the further course of the disorder can be favorably influenced by avoiding or reducing these risk factors. Recommendations: • Quit smoking • Reduce weight • Treat hyperlipidemia • Control diabetes • Reduce hypertension • Acetylsalicylic acid (aspirin) • Exercise Quitting smoking and losing weight are probably the most challenging tasks for patients, and most patients must seek professional help. Hyperlipidemia can be very well controlled with medication in many patients, and treatment is inexpensive. It is interesting to note the result of a study on the effect of perfusion-stimulating medications on walking distance. Cholesterol synthesis inhibitors had the best long-term effect (Momsen et al 2009). Diabetes must be rigorously treated. Hypertension is also usually controllable with medications (and by weight loss as well). Small doses of acetylsalicylic acid have long been recognized as prophylaxis against recurrence and possibly for primary prevention. Clopidogrel may be tried in those patients who do not tolerate aspirin. Finally, those who do not enjoy walking or cycling may consider finding a walking companion, adopting a dog, or joining an athletic club that features a coronary sports group. Certainly there are few diseases that can be so extensively clarified by a thorough patient history as can early-stage peripheral arterial occlusive disease. The cardinal symptom is intermittent claudication. Typically this manifests itself as lower leg pain or cramps that occur after the patient walks a certain distance and disappear after a rest. Less often such cramps will occur in the thigh or buttocks. In such cases the cause is usually located in the iliac arteries. Walking distance should be measured on a treadmill. There are numerous noninvasive diagnostic methods. The most important one is measuring systolic blood pressure in all four extremities to determine the ankle-brachial index (ABI), also referred to as the ankle-brachial pressure index (ABPI). Where pressure varies between the right and left arms, the higher value serves as reference. The ABI is determined for each leg. Unreasonably high ABI values are not uncommon in patients with diabetes. This is due to sclerosis of the arterial media, which reduces the compressibility of the arteries of the leg regardless of blood pressure. Normal values for the ABI lie between 1.1 and 1.0. An ABI < 0.90 at rest is regarded as abnormal; after exercise it can decrease by 15–20%. This index is particularly suitable for documenting the success of treatment and evaluating the course of the disorder. The findings detected with the ABI become significantly more apparent with exercise (treadmill). The pressure drop along a stenosis is nearly proportional to the flow according to Poiseuille’s law. Therefore, when blood flow increases with exercise, the pressure gradient must also increase. Standardizing therapy and promptly agreeing on treatment options require that peripheral arterial occlusive disease be classified in defined stages (Table 1.1). For purposes of everyday clinical practice, Fontaine’s classification is sufficient and more practicable: Stage I: No symptoms ＝ no treatment. Usually it is an incidental finding, for example, occlusion of the superficial femoral artery that is fully compensated for by collaterals of the deep femoral artery. Stage IIa: Findings are compensated for at rest so that there is no absolute indication for treatment. Indications depend on lifestyle. A maximum walking distance of 200 m would render a postal delivery worker unfit for employment, whereas it hardly represents a significant restriction for an elderly retired person. Stage IIb: Where the maximum walking distance is < 200 m, one will usually opt for invasive treatment if the anatomical situation so permits. Stage III: Absolute indication for treatment. The leg is acutely at risk, for example, from thromboembolic occlusion of a major vessel. Stage IV: Treatment is clearly indicated and depends on the extent of findings, the vascular situation, and comorbidities (very often diabetes mellitus). Critical limb ischemia (CLI), a common term, is defined as chronic pain at rest, ulceration, or gangrene secondary to peripheral arterial occlusive disease. It is important to distinguish this from acute ischemia (stage III, see below). CLI is a clinical category but should be corroborated by objective examinations (ulcers on the lower leg are usually caused by venous pathology, foot ulcers by arterial). Revascularization is the best therapy. Systemic antibiotic treatment is indicated in cases of infection. Causes: • Arterial thrombosis (thrombosed bypass, thrombosed popliteal artery aneurysm) • Embolism Clinical symptoms: • Pain • Lack of pulse (confirmed by Doppler ultrasonography) • Pallor • Paresthesia • Palsy Important: Cause must be identified immediately as irreparable damage could otherwise result. Angiography wherever possible. Anticoagulation (heparin). Treatment options: • Thrombolysis • Aspiration thrombectomy • Surgery (especially with proximal embolisms and in popliteal aneurysm) In 2007, recommendations for defining the respective indications for open surgical and interventional treatment were published for the second time under the name TASC II (Norgren et al 2007). Interventional treatment is recommended for a constellation of findings of type A and surgical treatment for type D. Findings of types C and D can be treated by surgical or interventional means, depending on the patient’s general health and the experience of the attending physicians. Type A: • Unilateral or bilateral stenoses of the common iliac artery • Unilateral or bilateral short stenoses (< 3 cm) of the external iliac artery Type B: • Short stenoses (< 3 cm) of the infrarenal aorta • Unilateral occlusion of one common iliac artery • Isolated or multiple stenoses of one external iliac artery with a total length of 3 to 10 cm and not extending into the common femoral artery • Unilateral occlusion of the external iliac artery not extending to the origin of the common femoral artery Type C: • Bilateral occlusion of the common iliac arteries • Bilateral stenoses of the external iliac arteries with a total length of 3 to 10 cm and not extending to the origin of the common femoral artery • Unilateral stenosis of the external iliac artery extending into the common femoral artery • Unilateral occlusion of the external iliac artery with involvement of the origin of the internal iliac or common femoral arteries or both • Severely calcified unilateral occlusion of the external iliac artery with or without involvement of the origins of the internal iliac or common femoral arteries Type D: • Infrarenal occlusion of the aorta • Diffuse bilateral disease of the aorta and iliac arteries requiring treatment • Diffuse multiple unilateral stenoses of the common iliac, external iliac, and common femoral arteries • Unilateral occlusion of the common iliac and external iliac arteries • Bilateral occlusion of both external iliac arteries • Stenoses of the iliac arteries in patients with an aortic aneurysm requiring treatment but unsuitable for an endoprosthesis, or with other disorders requiring open surgery of the aorta or iliac arteries Type A: • Isolated stenosis < 10 cm long • Isolated occlusion < 5 cm long Type B: • Multiple stenoses or occlusions, each < 5 cm long • Isolated stenosis or occlusion < 15 cm long without involvement of the distal popliteal artery • Isolated or multiple lesions in the absence of continuous arteries of the lower leg suitable as recipient vessels for a distal bypass • Severely calcified occlusion < 5 cm long • Isolated popliteal artery stenosis Type C: • Multiple stenoses or occlusions > 15 cm total length with or without severe calcification • Recurrent stenosis or occlusion requiring treatment after two endovascular interventions Type D: • Chronic total occlusion of the common femoral artery or superficial femoral artery > 20 cm and involving the popliteal artery • Chronic total occlusion of the popliteal artery and the proximal arteries of the lower leg (trifurcation) However, Sixt et al (2008) demonstrated in a study published in 2008 that the TASC II recommendations are not necessarily to be interpreted as binding guidelines. In 375 patients with aortoiliac disorders, nearly identical results were achieved for the four TASC II classifications (primary patency rates after 1 year were 89, 86, 86, and 85%). The conclusions drawn by Conrad et al (2009) for the arteries of the leg were very similar. Assisted patency after 3 years was 94.3% for TASC II categories A and B, and 89.7% for categories C and D. In everyday practice one should invariably consult one’s surgeon when deciding whether to opt for surgical or interventional treatment. Regular consultations conducted candidly and without regard for personal ambition will quickly give each individual a realistic idea of the other specialist’s skills. This in turn will help one to decide which treatment is indicated. Familiarity with the TASC II recommendations makes it easier to define reasonable limits of one’s capabilities with respect to the surgeon and also with respect to patients’ expectations. It is wise to avoid the pitfall of viewing the surgeon as a rival. When in doubt self-restraint may be the best policy. It is a bitter setback when to fail after having argued in favor of treating a specific patient. The converse is true when one overcomes one’s own hesitation and complies with a colleague’s request that one treat a difficult case. The literature documents the following trends over the last 10 to 15 years: • Even in the arteries of the leg (especially in the thigh), endovascular procedures have become established as the treatment of choice. • They are employed early and are often combined with endovascular interventions at other levels (pelvis and lower leg). This is presumably the reason for a decrease in the rate of amputation by 25 to 38% over 10 years (Egorova et al 2010, Goodney et al 2009). • In the superficial femoral artery the primary patency rates are significantly worse than in the iliac arteries. However, good middle-term results have been achieved with second interventions. • As expected, the results correlate with the TASC categories, although the differences are small (DeRubertis et al 2007). • In contrast to the coronary arteries the processes that lead to recurrent stenosis in the arteries of the leg are not complete within 6 months (Shammas 2009). Optimal results require the following: – Excellent angiographic results of intervention with little dissection and residual stenosis – Protection of the arteries of the lower leg and reduction in the growth of smooth muscle cells by means of pharmacological intervention It is a privilege to be able to conduct the consultation with the patient prior to obtaining informed consent. It is one of the most noble tasks the physician performs. Only this consultation can create the trust the patient needs to believe or even to know for certain that one can help, that one is the right physician to perform this intervention. For the physician as well it is of great importance to know that he has gained the patient’s trust. This person believes in the chances of improvement and is not terrified of all the possible complications described in the patient handout. Naturally the patient must be informed about possible risks, and patient handouts are clearly helpful in listing them comprehensively. Yet one shudders at the thought that patients should simply sign a form relinquishing all control to a physician they have never met. This reflects poorly on those physicians who never took the opportunity to place the long list of risks in perspective and to kindle their patient’s trust in the far greater chance of improvement or healing. Whenever possible, one should not leave it to the family doctor, the attending physician on duty on the ward, or a younger colleague to discuss the procedure with the patient and obtain informed consent. Just do it yourself! One should speak so the patient will understand. And above all, one should listen and have the patient describe his or her complaints. One should ask questions in a way that leads the patient to those details that are of importance. In simple words one should describe what can presumably be done to address these complaints, and describe how it all works. If there is anything left to the patient handout let it be all the rare complications.
Clinical Presentation of Peripheral Arterial Occlusive Disease
Staging According to Fontaine and Rutherford
Other Clinical Definitions
Critical Limb Ischemia
Acute Ischemia (“Cold Leg”), Stage III
Trans-Atlantic Inter-Society Consensus (TASC) II
Aortoiliac Occlusive Disease
Occlusive Disease of the Leg Arteries
Consultation with the Patient
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