Letter Regarding Article by Martinelli et al, “Risk Factors and Recurrence Rate of Primary Deep Vein Thrombosis of the Upper Extremities”
To the Editor:
This letter regards the article by Dr Martinelli et al,1 “Risk factors and recurrence rate of primary deep vein thrombosis of the upper extremities.”
Although the focus of the study published by these authors is in reference to the possible coagulopathy that patients may have as a predominant risk factor to develop upper vein thrombosis, as well as the possible influence of oral contraceptives, there is no reference to the Paget-Schroetter syndrome, also known as “effort thrombosis of the subclavian vein,” that some of their patients seemed to have.
A strenuous muscular effort with the arms was recorded in one fourth of their patients. The current acceptable treatment for that condition is lytic therapy followed by surgery. The patients were followed up to investigate the rate of recurrence. However, if surgery is not done, the problem will invariably recur.2–4 If patients are treated with only anticoagulants and even thrombolytics but no surgery, I expect the recurrence rate to be high. The cause of effort thrombosis is mechanical obstruction and pinching of the subclavian vein at the thoracic outlet. It could be a single episode or chronic from repetitive pinching.5 Most of the patients who suffer this condition do not have any abnormality in their coagulation mechanism. It is caused by a direct injury to the endothelium. The investigators found that there was no difference in thrombophilia between the group of patients who developed thrombosis and the ones who did not. The treatment for Paget-Schroetter syndrome must be implemented as an emergency.4 This entails the use of thrombolytics followed by surgery to decompress the thoracic inlet and widening of the vein, usually using a vein patch. The results of this treatment are quite effective with reestablishment of vein patency and normal flow.1–6 The patients are anticoagulated postoperatively for only 8 weeks, and they are cured on no chronic anticoagulants and fully functional to return to their usual occupations or sport activities. This information may help the authors to become more familiar with this syndrome, which always requires emergency care.
The Paget-Schroetter syndrome, also known as effort thrombosis of the axillary-subclavian vein, usually develops secondary to heavy arm exertions. The underlying mechanisms of thrombosis are thought to be a venous compressive anomaly at the thoracic outlet or intimal damage due to a strain of the subclavian and axillary veins by retroversion or hyperabduction of the arm. These movements are usually done during sport activities, and the Paget-Schroetter syndrome has been frequently reported in athletes.1 Although thrombolysis and surgery are the most common approaches to the treatment of the syndrome, there is no definite consensus on treatment because no randomized trial is available so far.2 None of the patients included in our study3 received treatment with thrombolytic agents or underwent surgery for decompression of the thoracic outlet (resection of the first rib, anterior scalene muscle, or costoclavicular ligament), despite the fact that one fourth of them reported strenuous effort with the arm at the time of thrombosis. One reason for this finding may be that patients with Paget-Schroetter syndrome were not referred to the Thrombosis Center for a thrombophilia screening because the syndrome itself had been considered sufficient to cause thrombosis. This may also explain the low recurrence rate of upper-extremity deep vein thrombosis in our series, which differs from the high recurrence rate reported in patients with Paget-Schroetter syndrome treated with anticoagulants only.4 Whether or not the syndrome itself justifies avoiding thrombophilia screening is questionable, and Dr Molina’s assumption that most patients with the syndrome do not carry thrombophilia abnormalities remains to be demonstrated. The design of our study allowed us only to state that the prevalence of thrombophilia abnormalities was similar in patients with and without a history of strenuous muscular effort. We believe that deep vein thrombosis, being a multifactorial disease, often occurs in the presence of multiple concomitant risk factors of different weight and role.