Retrospective review on isolated distal deep vein thrombosis (IDDVT) - A benign entity or not?
BACKGROUND
Isolated distal deep venous thrombosis (IDDVT) is traditionally associated with less severe clinical sequelae, with ongoing debate on multiple aspects of its management. Despite numerous studies evaluating its acute management, there remains a paucity of data evaluating long-term complications such as recurrence and subsequent malignancy. We aim to evaluate the characteristics of IDDVT in institutions that routinely perform whole leg ultrasonography, and the risks of recurrence and complications in comparison to major venous thromboembolism (major VTE; defined as above-knee or proximal DVT and pulmonary embolism (PE)).


METHODS
Retrospective evaluation of consecutive IDDVT and major VTE from July 2011 to December 2012 in a hospital network in Melbourne, Australia. Patients were followed up for a minimum of 24months. Patients with active malignancy were excluded.


RESULTS
Of 1024 VTE cases, there were 164 non-cancer patients (92 males, 72 females, median age of 61years) with IDDVT. Compared to major VTE, IDDVT was more likely to be provoked (73% vs 59%, p<0.01), has shorter duration of anticoagulation (median 3.5months vs 6.0months, p<0.01) and less clinically significant bleeding (2.4% vs 6.7%, p=0.05), independent of duration of therapy. Recurrence was non-inferior compared to major VTE (10% vs 7%, p=0.36) and 60% recurred with major VTE. Three (1.8%) were subsequently diagnosed with cancer (vs 1.9% in major VTE, p=0.97).


CONCLUSIONS
IDDVT has non-inferior rates of recurrence and subsequent cancer detection compared to major VTE and hence, its clinical significance should not differ from major VTE. Further studies are required to determine the adequate length of anticoagulation.
Northern Health, Epping, Melbourne, VIC, Australia; Austin Health, Heidelberg, Melbourne, VIC, Australia; Florey Institute of Neurosciences and Mental Health, Parkville, VIC, Australia; University of Melbourne, Parkville, VIC, Australia. Electronic address: Prahlad.Ho@nh.org.au.
Prahlad
P
Ho
Northern Health, Epping, Melbourne, VIC, Australia; Austin Health, Heidelberg, Melbourne, VIC, Australia.
Hui Y
HY
Lim
Austin Health, Heidelberg, Melbourne, VIC, Australia.
Chong C
CC
Chua
Austin Health, Heidelberg, Melbourne, VIC, Australia.
Matthew
M
Sleeman
Northern Health, Epping, Melbourne, VIC, Australia; University of Melbourne, Parkville, VIC, Australia.
Mark
M
Tacey
Florey Institute of Neurosciences and Mental Health, Parkville, VIC, Australia.
Geoffrey
G
Donnan
Australian Centre for Blood Diseases, Prahran, VIC, Australia; Monash University, Clayton, VIC, Australia.
Harshal
H
Nandurkar
D000925:Anticoagulants / Q000627:therapeutic use; D001315:Australia / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D020246:Venous Thrombosis / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology* / Q000473:pathology*
D000925:Anticoagulants
Bleeding; Deep vein thrombosis; Epidemiological studies; Recurrence