Management of Chronic Venous Insufficiency

Epidemiology and Risk Factors of Chronic Venous Disease

Chronic venous disease (CVD) is a condition that affects the superficial and deep venous systems resulting in venous hypertension and a cascade of biochemical and vessel wall changes that lead to a spectrum of pathologies ranging from telangiectasias to venous stasis ulcerations. Chronic venous insufficiency (CVI) is an advanced form of CVD, generally presenting with lower extremity edema, trophic skin changes, and venous ulcerations. This chronic condition has often been neglected by providers because of its chronic and subtle progression and the lack of emphasis on its clinical presentation and pathophysiology within the general medical education curriculum. Unfortunately, CVI has a major impact on society, negatively affecting the quality of life of patients and consuming large health care dollars and resources.

CVD is highly prevalent in the United States and western Europe but its true prevalence is unknown because of variability in the definition of the disease and methodology of evaluation. An estimated 25 million people in the United States have chronic venous disease, with 2 million to 6 million having CVI, and nearly 500,000 have venous stasis ulceration. In the Edinburgh Vein Study, a cross-sectional study of a random sample of 1566 subjects, the prevalence of telangiectasias and reticular veins was approximately 80% and 85%, varicose veins 40% and 16%, and ankle edema 7% and 16% in men and women, respectively. Various studies have shown that the prevalence of varicose veins ranged from 2% to 56% in men and 1% to 60% in women. This prevalence increases with age. In the Edinburgh study, the overall prevalence of venous reflux by duplex ultrasound was 9.4% of men and 6.6% of women but rose to 21.2% in men and 12.0% in women over the age of 50. Similarly trophic skin changes seem to increase with age with a prevalence of 1.8% in young women 30 years to 39 years of age, and 20.7% in women over the age of 70 years. Finally, venous ulcers occur in approximately 1% of the general population and also increase with age.

The incidence of CVD or its occurrence within a defined period of time has been evaluated in the Framingham Study. Every second year and over a period of 16 years, subjects were examined for the appearance of varicose veins. The 1-year incidence rate of varicose veins was found to be 1.97% for men and 2.6% for women. In the Edinburgh Vein Study the annual incidence rate in developing varicose veins was 1.4%, with incidence rates similar in men and women.

Several studies have suggested that women have a higher incidence of CVD but this has not been shown in more recent studies. Women are likely to be more aware of their varicose veins and therefore are more likely to participate in studies leading to a selection bias. Also, age-adjusted prevalence of CVD in females has not been consistently performed in studies. In addition, pregnancy is a risk factor for CVD and is likely to bias the overall prevalence of CVD against women. Race has also been linked to CVD. In the San Diego Population Study, CVD was less prevalent in Blacks and Asians when compared with subjects of European origin. Another study showed that English women are five times at risk of CVD than Egyptian women. Furthermore, other risk factors have been linked to CVD and they include obesity, standing occupation, pregnancy, heredity, and prior history of limb trauma. In the Edinburgh Vein Study subjects with a family history of venous disease were more likely to develop varicose veins (odds ratio [OR] 1.75). Also, in the same study obesity was associated with an age-adjusted OR of 3.58 with the development of CVI. In another study, multivariate logistic regression analysis showed that female gender (OR 2.2), increasing age (OR 2.2 to 2.8), a reported positive family history for varicose veins (OR 4.9), increasing number of births (OR 1.2 to 2.8), standing posture at work (OR 1.6), and higher weight (OR 1.2) and height (OR 1.4) were independent predictors of varicose veins.

CVI has a significant direct and indirect socioeconomic burden on society. In the United States, venous ulcerations resulted in a loss of 2 million workdays per year. In France and Sweden, 2.24 billion euros and 73 million euros were spent per year for the treatment of CVI, respectively. A study from Germany found that inpatient and outpatient direct costs were 250 million euros and 234 million euros, respectively, loss of working days costs were 270 million euros, and drug costs were 207 million euros. The presence of venous ulcerations also impacted on quality of life substantially with more than 20% of ulcers remained not healed within 2 years follow-up. These ulcers have been responsible for early retirement of 12.5% of workers with this condition.

Venous Anatomy and Physiology

Treatment of chronic venous insufficiency requires a good understanding of normal venous anatomy and physiology. The veins of the lower limbs are divided into the superficial venous system, the deep venous system, and the perforator veins, connecting the superficial and deep veins at various levels from the foot to the gluteal area ( Figure 27-1 ). The superficial venous system is located within the superficial compartment surrounded anteriorly by the hyperechoic saphenous fascia and posteriorly by the muscular fascia. Within the saphenous compartment reside the saphenous veins, accompanying arteries, and saphenous nerves. A saphenous vein exiting the saphenous compartment is better described as a tributary. The superficial veins of the lower limbs are numerous and interconnected in a network that eventually empties into two primary trunks that feed into the deep venous system: the great saphenous vein (GSV), and the small saphenous vein (SSV). These superficial veins connect to the deep system at the level of the common femoral vein for the GSV and quite often the popliteal vein for the SSV. Also, several perforators connect these superficial systems and their tributaries to the deep system. When discussing anatomy of the venous system, it is important to adhere to the current international nomenclature that has been adopted by the Union Internationale de Phlebologie (UIP) and is currently in use. Below is an anatomic description of the venous system of the lower limbs from this consensus meeting.

Superficial Veins of the Lower Limb

Great Saphenous Vein

The great saphenous vein (GSV) is the longest and main superficial vein of the lower limb. It begins at the medial end of the arch as a continuation of the medial marginal vein of the foot. It ascends slightly anteriorly to the medial malleolus and continues anteromedially in the lower leg before it takes a short posterior course behind the medial condyle of the tibia at the level of the knee. In the lower thigh it ascends anterolaterally, then takes a medial course to below the inguinal ligament, passing through the cribriform fascia that covers the fossa ovalis to join the common femoral vein (CFV) at the saphenofemoral junction (SFJ). The GSV is located within the saphenous compartment. The latter has been compared with the “Egyptian eye” when seen on a transverse scan by B-mode ultrasound ( Figure 27-2 ). The superficial fascia is the upper eyelid, the deep fascia is the lower eyelid, and the lumen of the GSV is the iris. Outside the “eye,” the saphenous trunk is called a superficial tributary even though it can still play the role of a main axial superficial vein. There are several anatomic variations to the GSV; it can be a single GSV within the “eye” and no large tributary, rarely two parallel GSV within the same compartment (true duplication), or a single GSV in the proximal thigh, and at various distances exit the “eye” to become a large subcutaneous tributary (present in about 30% of the time). Large tributaries running parallel to the entire length of the GSV outside the saphenous compartment can also be present and enter the GSV at different levels.

There are several valves in the GSV ranging from 8 to 20 in number. They are mostly located at the junctions with other veins. A constant terminal valve in the GSV is located 1 mm to 2 mm distal to the SFJ. Often, a preterminal valve is seen 2 cm distal to the terminal valve and delineates the distal limit of the SFJ area. At the SFJ, a confluence of proximal veins is seen and includes the superficial epigastric vein, superficial circumflex iliac vein, and external pudendal vein ( Figure 27-3 ). Their clinical importance is in their ability to transmit retrograde flow into the GSV despite a competent terminal valve. Also, the GSV receives many tributary veins; some may be large, including the anterior accessory saphenous vein (AASV) (present in 41% of subjects and entering the GSV within 1 cm of the SFJ), and posterior accessory saphenous vein (PASV), often entering the GSV distal to the preterminal valve at variable distance. In addition, the anterior thigh circumflex vein ascends obliquely into the anterior thigh and enters either the GSV or the AASV; the posterior thigh circumflex vein ascends obliquely into the posterior thigh and may originate from the thigh extension of the small saphenous vein (SSV), directly from the SSV, or from the lateral vein plexus, and enters the GSV. The lateral extension of the SSV into the thigh that connects with the posterior circumflex vein is often called the vein of Giacomini ( Figure 27-4 ).

Anterior Accessory Saphenous Vein

The AASV enters laterally the GSV just below the SFJ. Close to the SFJ both AASV and GSV often share the same saphenous compartment. The AASV, however, has its own saphenous eye more distally and can be distinguished from the GSV by the “alignment” sign where it runs anterior and parallel to the GSV and in line with the femoral artery and femoral vein.

Posterior Accessory Saphenous Vein

The PASV ascends parallel and posterior to the GSV within its own fascial compartment. It is not always easily found and it connects at various lengths with the GSV below the SFJ area. The PASV can be present above or below the knee. The below-the-knee segment that connects to the GSV is called Leonardo's vein, or posterior arch vein, and is present in approximately 27% of subjects.

Small Saphenous Vein (SSV)

The small saphenous vein (SSV) is a continuation of the lateral marginal foot vein and ascends behind the lateral malleolus to the posterior aspect of the calf in between the medial and lateral heads of gastrocnemius muscle. The SSV lies within the interfascial compartment across its length. On transverse duplex ultrasound, the SSV appears within the “eye,” similar to the GSV. Proximally, it is within a triangular compartment outlined by the superficial fascia anteriorly, and the lateral and medial heads of the gastrocnemius muscle laterally and medially, respectively. The SSV generally terminates in the popliteal vein at the saphenopopliteal junction (SPJ) but not always ( Figure 27-5 ). The SPJ is mostly located within 2 cm to 4 cm above the knee crease but this can significantly vary. The SSV continues into the thigh as the thigh extension (TE). TE is present in 95% of subjects and is intrafascial in position within a triangular compartment defined by the superficial fascia anteriorly, the semitendinous muscle medially, and the biceps femoris muscle laterally. The TE may end in the inferior gluteal vein, connected via a sciatic perforator or posterolateral thigh perforator to the femoral vein, or connected to the GSV via the posterior thigh circumflex vein. Both the TE of the SSV together with the posterior thigh circumflex vein that empties into the GSV are described as the vein of Giacomini. The gastrocnemius veins may merge with the SSV to empty into the popliteal vein or they could empty directly into the popliteal vein near the SPJ. Like the GSV, there is a terminal valve in the SSV close to the popliteal vein and a preterminal valve generally located below the TE of the SSV.

Perforators of the Lower Limb

The superficial veins are connected to the deep veins via the perforator veins ( Table 27-1 ) that penetrate the deep fascia. More than 40 perforator veins have been described. The perforators are located at several levels in the lower limb: foot, ankle, lower leg, knee, thigh, and gluteal area ( Figure 27-6 ). From a historic point of view, they have been named after individuals who described them. Descriptive terms to their location are preferred and have been widely adopted, as follows:

• The perforators of the foot (venae perforantes pedis) are described into dorsal, medial, lateral, and plantar foot perforators.

• The ankle perforators (venae perforantis tarsalis) are the medial, anterior, and lateral ankle perforators.

• The perforators of the leg (venae perforantes cruris) are separated into four main groups:

  • Medial leg perforators (paratibial and posterior tibial). The paratibial perforators connect the GSV or its tributaries to the posterior tibial vein (PTV) and the posterior tibial perforators connect below the knee PASV to the PTV. These perforators are indicated by their location as upper, middle, and lower.

  • Anterior leg perforators connect the anterior tributaries of the GSV to the anterior tibial veins (ATV).

  • Lateral leg perforators connect veins of the lateral venous plexus to the peroneal veins.

  • Perforators of the posterior leg (medial gastrocnemius perforators, lateral gastrocnemius perforators, intergemellar perforators (connecting the SSV to the soleal veins) and para-Achillean perforators (connecting the SSV to the peroneal veins).

• The perforators of the knee (venae perforantes genus) are designated as medial, lateral, suprapatellar, infrapatellar, and popliteal fossa knee perforators.

• The perforators of the thigh (venae perforantes femoris) are separated into the following:

  • Medial thigh (perforators of the femoral canal and inguinal perforators) connecting the GSV or its tributaries to the femoral vein

  • Anterior thigh

  • Lateral thigh

  • Posterior thigh (posteromedial, sciatic perforators, posterolateral) and pudendal perforators

• The perforators of the gluteal muscles (venae perforantes glutealis) are divided in superior, mid, and lower perforators.

TABLE 27-1

Perforator Groups and Subgroups in the Lower Limb

PERFORATOR GROUPS	SUBGROUPS
Foot	Dorsal, plantar, lateral, medial
Ankle	Anterior, medial, and lateral
Leg	Medial (paratibial and posterior tibial) [GSV or tributaries to PTV] Anterior [GSV tributaries to ATV] Lateral [lateral venous plexus to peroneal] Posterior (medial and lateral gastrocnemius, intergemellar [SSV to soleal]) Para-achillean [SSV to peroneal]
Knee	Medial, lateral, suprapatellar, infrapatellar, popliteal fossa
Thigh	Medial (femoral canal, inguinal), anterior, lateral, posterior (posteromedial, sciatic, posterolateral, pudendal)
Gluteal	Superior, mid, lower

ATV, Anterior tibialis vein; GSV, greater saphenous vein; PTV, posterior tibialis vein; SSV, small saphenous vein; […] indicates the superficial to deep vein connections of the perforator veins.

Physiology of the Venous System

The venous system functions as a large reservoir storing about 70% of the blood in a subject. It also serves as a low-flow, low-pressure conduit moving venous blood to the heart. Flow into the venous system travels against gravity and therefore a series of muscle pumps and valves are built in to assist in this flow. Predominantly calf muscle contraction and to a lesser extent foot and thigh muscles increase fascial compartment pressures, compressing the intramuscular veins and venous plexi in the calf and driving venous flow upward against gravity. Negative intrathoracic pressure also assists in the process of forward flow. A series of unidirectional bicuspid valves are present in the lower limb and superficial venous systems that continue to ensure a forward flow of blood to the heart against gravity. Valves are also present at the perforators that prevent flow from the deep system back into the superficial system. The CFV typically has one valve. The inferior vena cava and common iliac veins have no valves. Infrequently, a valve can be seen in the external iliac vein. The infrainguinal veins have several valves located at different levels but most seem to concentrate at the knee level and below.

The resting standing venous pressure is approximately 80 to 90 mm Hg. Following ambulation, the muscle contraction moves the venous flow forward emptying the venous system and dropping the pressure to 15 to 30 mm Hg. When muscle relaxation occurs the venous system refills slowly (more than 20 seconds) from arterial inflow into the superficial and deep veins, distending the veins and allowing the valves ( Figure 27-7 ) to open, creating a single pipe of fluid with a pressure at the ankle equal to the height of the column of blood. In a competent valve system, contraction of the muscle leads to quick emptying of the veins with no refluxing of flow backward, and a quick drop of pressure in the venous system typically more than 50% decrease from the resting standing pressure.