Peripheral vascular diseases are a diverse collection of disorders that affect all organ systems. Although peripheral arterial disease (PAD) is the disease most commonly encountered by the cardiologist, disease of the lymphatics and veins is equally common (globally more so). For the cardiologist or internist with an interest in vascular disorders, a systematic and comprehensive approach is required. This chapter covers commonly encountered areas of vascular disease including lymphedema, venous disease, and PAD. Accompanying chapters on aortic and cerebrovascular disease address those areas in more detail.
Lymphedema is an abnormal buildup of lymphatic fluid in the dermal and subcutaneous tissues. In contrast to the venous system, the fragile and easily damaged lymphatic vessels carry a low volume of flow but do so actively, propelling flow from the periphery centrally via peristalsis. As vessels coalesce, larger and larger conduits form eventually becoming the thoracic duct that empties into the left subclavian vein.
Lymphedema may be primary or secondary in etiology. Primary lymphedema may be congenital (present at birth) or, more commonly, present in the early teen years (lymphedema praecox) and is more common in females presenting around menarche. Lymphedema tarda presents in later years and is a diagnosis of exclusion because a secondary cause of is much more likely in this age group. Trauma, recurrent infection, obstruction, infiltration, and radiation all cause lymphatic vessel damage. Lymph nodes are located along lymphatic vessels. Globally, lymphedema is the most common vascular disease, affecting 90 to 120 million people.1 Mosquito-borne infection with filaria is endemic in tropical countries. However, cases occur within the contiguous United States including "cold weather" states.2 Upper extremity lymphedema may occur after axillary node dissection. Recurrent cellulitis is common in patients with lymphedema and may be an initiating, exacerbating, or complicating event. Streptococcus is the most common organism, entering the skin through a crack in the toe webs caused by tinea pedis. The organism damages the lymphatic channels and the lymph nodes, with repeated infection eventually obliterating the vessel.3
History and physical examination make the diagnosis in the majority of cases. Unlike edema and lipedema, lymphedema involves the toes and often affects them first. The skin is thickened and takes on an orange peel consistency (peau d'orange) (Fig. 109–1). A diffuse, flat, warty consistency may affect the skin over time. Dependent edema spares the toes unless secondary lymphedema is present. Lipedema is caused by excess fatty deposits in the leg and may be difficult to differentiate from lymphedema if the foot is not examined. However, with lipedema, the toes are spared, and there is often a ridge or fold overhanging the ankle.
Left leg lymphedema with typical skin changes. Note the toes are edematous and the skin is thickened in a classic peau d'orange pattern with ...