Superficial Thrombophlebitis

Etiology

A hypercoagulable state, prolonged immobilization, or vessel wall trauma may increase the risk of SVT. Superficial thrombophlebitis accounts for 5.4% of the adjusted population attributable risk for initial DVT or PE. SVT has been the presenting symptom in certain inheritable thrombophilias. According to several studies, it occurs in 11% to 15% of patients with protein C or S deficiency and approximately 40% with factor V Leiden mutation.[5] However, another study showed that these results were not statistically significant.[6] In pregnancy, the risk of SVT is akin to that of DVT, most commonly in the postpartum period. Advanced age, exogenous estrogens, autoimmune or infectious diseases, obesity, recent trauma or surgery, active malignancy, history of venous thromboembolic disease, and respiratory or cardiac failure also increase the risk of SVT.[2][3][4][6] Prior occurrences increase the risk of subsequent ones. As noted in 75% to 88% of cases, varicose veins are considered the most important clinically identifiable predisposing factor for SVT.[2][3][4][5][6]

Epidemiology

The true incidence of superficial thrombophlebitis is unclear. In France, 1 community-based study noted the incidence of SVT to be 0.64%, while a different community-based study found the incidence to be half that of DVT and similar to PE.[3][6] Other studies suggest its prevalence in the general population is 2 to 6 times higher than the incidence of DVT and PE.[2][4][6] SVT is commonly seen in the outpatient population, usually, women, who made up 50% to 70% of the affected patients in 1 study; 60 years mean age; a body mass index that exceeds 25 kg/m2; and those with varicose veins.[2][3][6] For people who have a history of SVT, the lifetime risk of DVT or PE increases 4 to 6 times. While the 3-month mortality is about 5% in patients with DVT or PE, it is less than 1% for those with SVT. One suggested reason for the lower mortality in patients with SVT is the younger age of the patients with fewer associated comorbidities.[3] The migration of the thrombus towards the deep veins at the saphenofemoral junction, the saphenopopliteal junction, or from a perforating vein during a hypercoagulability state may cause the association between SVT and DVT or PE.[3][6] 

Pathophysiology

Superficial thrombophlebitis starts with microscopic thrombosis. When venous turbulence or stasis, vessel wall injuries, abnormal coagulability, or vessel wall injuries, microthrombi could propagate and subsequently form macroscopic thrombi. Vascular endothelial injury reliably results in thrombus formation by triggering an inflammatory response that results in immediate platelet adhesion. Platelet aggregation is mediated by thrombin and thromboxane A2.

History and Physical

Patients with superficial thrombophlebitis typically present with a reddened, warm, inflamed, tender area overlying the track of a superficial vein. There is often a palpable cord. Some surrounding edema or associated pruritis may occur. Significant swelling of the limb is more commonly associated with DVT and should only be attributed to SVT after DVT has been excluded.[1][2][3][6][7] Patients may have a history of antecedent trauma, which can include intravenous cannulation or infusion of irritants, such as recent sclerotherapy for varicose veins.[2][8] A careful history is critical to identify risk factors for venous thromboembolism. Initial presentation in patients older than 40 without other risk factors should prompt consideration of underlying malignancy.[2][6] Patients with migratory thrombophlebitis, a well-documented paraneoplastic phenomenon, should also be further evaluated for underlying malignancy.[2][6][9] Migratory thrombophlebitis is usually associated with pancreatic or other visceral malignancies and is often called Trousseau syndrome. It can be the presenting complaint in 5% to 15% of pancreatic cancer, particularly of the body and tail.[6][9][10]

Evaluation

Traditionally, superficial thrombophlebitis was a clinical diagnosis. However, with the increased realization of association with concomitant DVT or PE, compressive ultrasonography is recommended.[2][5][6] Physical examination does not adequately identify the extent of the disease; it has been shown to underestimate it in up to 77% of instances. Compressive ultrasonography can identify concomitant DVT, evaluate the extent of the thrombus, and confirm the diagnosis.[2][6] The Prospective Observational Superficial Thrombophlebitis (POST) study reviewed venous duplex screening of the affected lower limb and showed that 23.5% of patients had concurrent DVT. More than half of these DVTs were not contiguous with the SVT; 17% were noted to affect the contralateral lower extremity, while only 1% had an isolated DVT in the contralateral limb. These findings support the regular use of ultrasound to evaluate SVT. The POST study also sought to establish the ultrasonic findings that increased the likelihood of associated DVT. It found that the risk substantially increased if a perforating vein was involved, with an odds ratio of 8.1, or if an SVT was present less than 3 cm from the saphenofemoral junction, which had an odds ratio of 3.3.[6] D-dimer testing is of limited utility in detecting SVT. It is variably elevated in SVT and cannot be used to distinguish isolated SVT from DVT.[2]

Experts debate whether patients who present with extensive superficial thrombophlebitis without an apparent inciting reason should have an evaluation for thrombophilia, given that hypercoagulability is associated with SVT. However, to date, no conclusive studies have identified causation between hypercoagulability and SVT.[2] As previously mentioned, migratory thrombophlebitis warrants evaluation for visceral neoplasm. Patients older than 40 years with their first episode of thrombophlebitis should also be evaluated for underlying neoplasm.[6][9] Superficial thrombophlebitis of the superficial breast veins is referred to as Mondor disease. A case series from 1992 noted a 12.7% risk of associated breast cancer, but it was a limited study, so it is argued that the incidence could have been overrepresented. Therefore, mammography could be considered in patients with this presentation.[6]

To help establish the pretest probability for the presence of DVT in patients with SVT, the Internal Carotid Artery Occlusion (ICARO) Study Group has outlined the following 5 variables: 

• Active malignancy (1.5 points)
• Limb edema (1.5 points)
• Age of fifty years or more (1 point)
• A ropelike sign (-1 point)
• Unprovoked SVT (-1 point)[11]

The ICARO Study Group suggested this scoring system to help when assessing such patients for coexisting DVT:

• Low probability (less than zero points): 1.1% likelihood
• Intermediate probability (score of 0 to 1): 12.0% likelihood
• High probability (scored 1.5 or more points): 32.3% likelihood[11]

However, a recent study using this scoring system does not support its validity.[12]

Treatment / Management

Despite the number of studies performed, there is still debate on the appropriate treatment for superficial thrombophlebitis. Multiple strategies have been proposed to control symptoms and decrease the extension of thrombosis and risk for PE in low-risk superficial thrombophlebitis.[2] Low-risk thromboses are those not associated with the presence of or predisposition to other thromboembolic diseases. In these cases, the consensus is that nonsteroidal anti-inflammatory agents, heat, and anticoagulants are all reasonable.[7] Those who are at higher risk include patients with an SVT in the lower extremity that is at least 5 cm in length; SVT proximal to the knee, especially within 10 cm of the saphenofemoral junction; the presence of severe symptoms; greater saphenous vein involvement; previous SVT/venous thromboembolic disease; active malignancy; or recent surgery.[6] Based on the Cochrane review published in 2018, these patients should receive fondaparinux 2.5 mg/day subcutaneously for 45 days.[1](A1)

This Cochrane review also evaluated topical and surgical treatments. Still, it noted that the data regarding these treatments and their effects on venous thromboembolic disease is too limited, so further studies are recommended at this time.[1] Rivaroxaban 10 mg daily for 45 days was found to be non-inferior to fondaparinux in preventing venous thromboembolic complications, with a comparable safety profile in the SURPRISE trial. However, the Cochrane review recommended further research on its use and the other direct oral factor-X or thrombin inhibitors.[1][13] Additionally, further study is recommended on the use of nonsteroidal anti-inflammatory agents and low molecular weight heparins.[1] Multiple agents have been evaluated for treatment in patients who develop superficial thrombophlebitis from an infusion. Per the 2015 Cochrane review of this topic, there is no consensus recommendation on the safety, dose required, or therapy duration for topical treatments, nonsteroidal anti-inflammatory agents, or systemic anticoagulation.[8] Practices in the United Kingdom suggest using compression stockings with or without additional therapies. Still, there is no current recommendation for or against their use in the United States of America.[2][6] Antibiotics are useful only with clear infection.[2](A1)

For Trousseau syndrome, the main priority is to eliminate the underlying malignancy. However, as this is commonly a challenge, heparin is the recommended treatment, given that multiple pathways contribute to developing the thrombus. Low molecular weight heparins have been used, but some have been less effective than heparin; therefore, further studies are recommended. Fondaparinux has also been evaluated but found to be less efficacious than heparin, and the utility of this agent also requires further study.[9] A case report on the topic recommended the initial treatment with heparin followed by oral anticoagulants but did not specify a particular agent or dosing schedule.[10] Mondor disease, discussed separately, is usually self-limited and benign and resolve in 4 to 8 weeks. However, if it is due to vasculitis, malignancy, or a hypercoagulable state, treatment is aimed at the underlying cause.[14](B3)

Differential Diagnosis

When evaluating a patient, it is essential to keep superficial thrombophlebitis on the differential. Other considerations include cellulitis, venous thromboembolic diseases, hematoma, lymphangitis, lymphedema, vasculitis, tendonitis or sports-related injuries, and venous insufficiency.[15][16][17][18][19]

Prognosis

The prognosis for Superficial thrombophlebitis is related to the underlying cause. Low-risk SVT is generally favorable, but there is a definite risk for recurrent disease. In those with higher-risk SVT, the overall prognosis is also positive with appropriate treatment. For those with SVT due to underlying malignancy, the prognosis is related to the causative process.

Complications

DVT and PE are significant complications of superficial thrombophlebitis. Multiple studies have found concomitant DVT with SVT in 6 to 36% of patients. These same studies clinically suspected concomitant PE in 2 to 13%, and regular performance of lung scans revealed the rate of asymptomatic PE approached 33%.[3] Other retrospective studies from both primary and secondary/tertiary centers reported concomitant DVT or symptomatic PE on the initial presentation to be 25 to 30%. About 5 to 7% of these patients had symptomatic PE.[3][4] However, the incidence of coexisting PE increased to 17% with a more rigorous screening process for asymptomatic patients.[4] Patients with thrombus up to 3 cm from the saphenofemoral junction should be treated for DVT, given that 14 to 70% progress to DVT.[4][5]