Deep vein thrombosis, chronic venous insufficiency, and postphlebitic syndrome form a series of pathophysiological events that may be triggered by very common pathologies predisposing for venous thromboembolism.
The vast majority of PS patients has a history of DVT, most likely of recurrent DVT. In most cases, DVT has been diagnosed a few months ago, but latency periods of several years have also been reported. Idiopathic PS, i.e., manifestation of PS-related symptoms without previous diagnosis of DVT, has been described but most likely results from undiagnosed DVT and subsequent CVI.
Patients normally present with unilateral lesions of ankles or calfs. PS-associated symptoms largely resemble those of DVT and CVI. Patients generally claim their legs to feel heavy and tire easily. Their skin is tender, in many cases even painful. If the ankles are affected, pain may be provoked by calf compression since this measure increases venous pressure in more distal regions. Cramps are commonly experienced. Pruritus and paresthesias indicate dermatological lesions and may precede or accompany stasis dermatitis. Leg ulcers are long-term complications of DVT and will not be observable in patients presenting with acute thromboembolism . Further dermatological symptoms that may be observed in PS patients are lipodermatosclerosis, hyperpigmentation and induration.
Patients commonly find relief in elevating their legs while long periods of standing or walking cause an exacerbation of symptoms. Consequently, symptoms tend to worsen over the course of the day.
PS diagnosis is based on the patient's medical history, physical examination and visualization of deep veins draining the affected area.
Both medical history and physical examination may, however, not allow for a clear distinction between DVT, CVI and PS if leg ulcers are not present. A clinical score developed by Villalta and colleagues has been proven very helpful to this end :
Duplex ultrasonography may be applied to rule out DVT and to confirm symptomatic CVI. This technique yields reliable and reproducible results, is of low cost and readily available. Typical findings are venous reflux and lack of compressibility due to fibrotic reorganization of vein walls. Detailed protocols are described elsewhere .
Causative treatment is not available; therapy of PS aims at cure of dermatological lesions, reduction of venous pressure and prevention of relapses. Patients may achieve a state of largely asymptomatic CVI, but the functionality of defective venous valves cannot be restored. Remodeling processes that led to fibrotic remodelling of the vessel's wall is only partially reversible.
The following measures may be taken:
PS is related with significant morbidity and reduces the life quality of affected individuals. Although the life expectancy of PS patients may be reduced, this is likely due to comorbidities predisposing for thromboembolic events like stroke, myocardial or renal infarction.
Currently available treatment options generally provide symptom relief. If patients are willing to take certain lifestyle decisions, e.g., if they are able to reduce weight and take care of their legs, life quality and possible life expectancy will further improve. However, CVI is largely irreversible and venous function may not be restored. Thus, patients may be cured from PS but will continue to suffer from CVI; they will most likely experience symptomatic periods throughout life. An overall improvement can be expected in most cases, though.
PS is the medical term for symptomatic CVI and CVI most commonly results from DVT. Thus, any condition predisposing for DVT should also be considered a risk factor for PS. In this context, the following pathologies should be contemplated as possible etiologic factors:
Patients presenting with recurrent DVT have particularly high risks of CVI and PS.
Additionally, obesity and tobacco consumption have been identified as risk factors for CVI . Traumatic lesions of vessels may also interfere with vein function, particularly if patients are forced to maintain the affected limb immobilized during convalescence.
DVT is a rather common disease and it has been estimated that 20 to 50% of DVT patients develop CVI and PS despite being adequately treated. This results in annual incidence rates of PS of 1 to 3 per 1,000 inhabitants . The individual risk of developing DVT, CVI and PS increases with age.
Gender predilection has been reported differently by various authors.
Venous thrombosis interferes with blood drainage and, consequently, with oxygen and nutrient supply to dependent areas. Ischemia, cell death and an acute inflammatory response occur in those tissues. These events result in edema formation and pressure enhancement. Furthermore, the vessel's wall and valves are damaged. In healthy individuals, venous valves impede reflux and blood stasis, but these structures cannot fulfill their functions in patients suffering from CVI. Blood stasis occurs and leads to pressure-induced fibrotic remodeling of venous walls, surrounding soft tissues and skin. These processes further impede venous return and lead into a vicious circle.
As can be deducted from the aforegiven description of pathophysiological events, venous hypertension in the lower limbs play a major role in PS pathogenesis . In CVI and PS patients, venous return becomes highly dependent on leg elevation and exercise, because both mediate a reduction of venous pressure. However, calf muscle function is increasingly impaired by inflammatory processes taking place in surrounding tissues. Thus, symptoms aggravate over the course of the day and patients only find relieve when elevating their legs over heart level.
Since the majority of PS patients is older than 60 years, prevalence rates of cardiovascular disorders in that patient group is high. Unfortunately, cardiac insufficiency further aggravates disturbance of venous return, edema formation and loss of venous function.
This chain of events can only be interrupted by recanalization - preferentially before irreversible tissue damage occurs - and, if need be, drug therapy of cardiac insufficiency.
Prevention of PS consists in prevention of venous thromboembolism by avoidance of the above mentioned risk factors, and adequate treatment of DVT and CVI. Recent studies suggest that catheter-directed thrombolysis and venous thrombectomy may be superior to conventional anticoagulant therapy of DVT with regards to the conservation of venous function . Long-term drug therapy may still be indicated to avoid relapses. Additionally, DVT and CVI patients should be advised to use compression stockings and to elevate their legs regularly in order to facilitate venous return.
Deep vein thrombosis (DVT) refers to the formation of a blood clot in determined vessels, most commonly in deep veins draining the lower limbs. Preference for these vessels is generally explained by the fact that a human's upright posture complicates venous return from anatomical structures situated far below the heart. Of note, DVT may also affect the upper limbs. DVT is associated with tenderness, pain, swelling and erythema. Patients presenting with DVT often receive anticoagulants, but catheter-directed thrombolysis and venous thrombectomy may also be considered.
Although the aforementioned therapeutic approaches cause significant symptom relief in most patients, affected individuals may continue to experience minor complaints. Their legs may still feel heavy and tire easily, and in some cases pain and swelling persist or reappear intermittently. Such observations suggest chronic venous insufficiency (CVI). Patients suffering from CVI may be asymptomatic at times, but functional impairment of venous valves and venous walls don't resolve spontaneously.
Over prolonged periods of time, CVI-associated symptoms may aggravate significantly. Patients may develop leg ulcers and skin fibrosis, claim pain, swelling and paresthesias. Ulcers may become infected and lead to even more severe dermatological lesions. The entirety of symptoms is referred to as postphlebitic syndrome (PS) or postthrombotic syndrome. Thus, PS describes symptomatic CVI.
Clinically, it is not always easy to distinguish between DVT, CVI and PS. Patients who present with PS have suffered from DVT and CVI previously and these diseases have most likely been triggered by systemic pathologies causing thrombophilia and/or thromboembolism. Genetic disorders, autoimmune diseases and atherosclerosis shall be mentioned as examples at this point. The majority of these disorders persists and thus, it is not unlikely that someone who suffered from DVT once will present with this condition again. In fact, recurrent DVT is a major risk factor for PS. Diagnostic imaging, namely Duplex sonography, is very helpful in diagnosing DVT or ruling out the latter in case of PS.
Causative treatment is not available and compression stockings are still the mainstay of PS therapy. Topical wound care is of utmost importance if patients present ulcers. Even though venous function cannot be restored, the prognosis for symptomatic relief is favorable.
Postphlebitic syndrome (PS), sometimes also referred to as postthrombotic syndrome, is the medical term for a symptom complex that may manifest in patients who previously suffered from deep vein thrombosis (DVT) and chronic venous insufficiency (CVI).
DVT occurs when a blood clot forms within determined vessels or is carried there. Most commonly, the lower legs are affected. The thrombus interferes with blood drainage and oxygen supply to dependent tissues. This leads to ischemia, cell death and an acute inflammatory response that does, in turn, provoke damage to the vessel's wall, venous valves, surrounding soft tissues and skin. Unfortunately, these pathophysiological events further hamper venous function, favor renewed thrombus formation, blood stasis and increased venous pressure.
If this vicious cycle cannot be interrupted, patients develop CVI. In general, CVI-associated symptoms wax and wane. However, severe vascular and dermatological lesions may manifest during symptomatic episodes - and in their entirety, they constitute PS:
Therapy of PS is challenging and the best treatment of this complicated condition is an early, adequate therapy of DVT and CVI. If PS manifests, patients are recommended to wear graduated elastic compression stockings, and to regularly elevate their legs above heart level. Wound care is of utmost importance to cure ulcers and other dermatological lesions.
However, venous function cannot fully be restored and although patients may be cured from PS, they will continue to suffer from CVI and will most likely experience symptomatic periods throughout life.