medwireNews: Coagulation tests are warranted in young women undergoing surgery for subclavian vein thrombosis (SVT), especially patients with Paget-Schroetter syndrome unrelated to physical activity, say US clinicians.
"We believe that the correlation between young small females is significant, as the thoracic inlet is smaller and more prone to thrombosis if a hypercoagulable state or disorder is present," explain Julie Freischlag (Johns Hopkins University, Baltimore, Maryland) and co-authors.
Identification of patients at greatest risk for hypercoagulability could help avoid unnecessary use of expensive clotting tests, they say.
The team reviewed medical records for 143 patients (79 female), aged an average of 32 years, who presented with SVT between 2003 and 2011. Hypercoagulation test results were available for 43 women and 12 men.
Overall, 14 (25.5%) of 55 patients with STV who underwent first rib resection and scalenectomy (FRRS) were found to have a hypercoagulable profile. Twelve were female and patients with thrombophilic disorders were significantly more likely to be younger than those without (27 vs 34 years). Hypercoagulable patients were also less likely to present after rigorous upper arm activity than those without.
Six patients were diagnosed with a factor V Leiden mutation, four with protein S deficiency, and two with plasminogen-activator inhibitor-1 (PAI-1) deficiency. In addition, one case each of protein C deficiency, anticardiolipin antibodies, factor VII mutation, factor II mutation, and antiphospholipid antibodies were identified.
Patients with deficiencies in PAI-1, protein C or protein S began a life-long course of anticoagulation therapy, the researchers note.
Of note, there was no significant difference in the outcome of FRSS between patients with and without a hypercoagulable profile with regard to venograms taken 2 weeks after surgery and all achieved long-term patency.
Fresichlag et al conclude that while hypercoagulability is a "rare finding" in patients with Paget-Schroetter syndrome associated with exertion, it should be considered in younger patients without activity before thrombosis.
"Consideration of this condition and judicious testing may yield improved outcomes and prevent future venous thromboembolic events in this subset of patients," they say.
By Lynda Williams, Senior medwireNews Reporter