title: Analysis of 1,338 Patients with Acute Lower Limb Deep Venous Thrombosis (DVT) Supports the Inadequacy of the Term "Proximal DVT".
abstract: OBJECTIVE
  For decades acute lower limb deep venous thrombosis (DVT) has been subdivided into distal DVT (isolated to the calf veins) and proximal DVT (extending above calf vein level). The aim of this study was to analyse the anatomical site and extent of thrombus in a large cohort of patients with acute DVT.
  
  
  METHODS
  A retrospective analysis of all patients aged >18 years, presenting with unilateral DVT according to duplex ultrasound investigation was performed at the University Hospital of Antwerp, Belgium (1994-2012). The anatomical site and extent of thrombus was registered and subdivided into five segments: calf veins (segment 1), popliteal vein (segment 2), femoral vein (segment 3), common femoral vein (segment 4), and iliac veins, with or without inferior vena cava (segment 5).
  
  
  RESULTS
  The median age of the 1,338 patients (50% male) included was 62 years (range 18-98 years). Left sided DVT was predominant (57%). DVT was limited to one segment in 443 patients, of whom 370 had DVT isolated to the calf veins (28% of total cohort). In 968 patients with what was previously called "proximal DVT", the median number of affected segments was three (range 1-5 segments). In this group iliofemoral DVT (at least involving segment four and/or five) was present in 506 patients (38% of total cohort), whereas the remaining patients had femoropopliteal DVT (at least in segment two and/or three but not in four or five). Iliofemoral DVT without thrombus in segments one and two was present in 160 patients (12% of total cohort).
  
  
  CONCLUSIONS
  This study illustrates the large diversity of thrombus distribution in patients previously described as having "proximal DVT". Therefore, this term should be abandoned and replaced with iliofemoral and femoropopliteal DVT. Patients with iliofemoral DVT (38%) could be considered for early clot removal; 12% of all patients with DVT would be ideal candidates for such intervention.
authors.affiliation: Department of Dermatology, Erasmus Medical Centre, Rotterdam, The Netherlands. Electronic address: m.demaeseneer@erasmusmc.nl.
authors.forename: M G R
authors.initials: MG
authors.lastname: De Maeseneer
authors.affiliation: Internal Medicine, University Hospital of Antwerp, Antwerp, Belgium.
authors.forename: N
authors.initials: N
authors.lastname: Bochanen
authors.affiliation: Department of Dermatology, Erasmus Medical Centre, Rotterdam, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: van Rooijen
authors.affiliation: SP Vascular Center, Limassol, Cyprus.
authors.forename: P
authors.initials: P
authors.lastname: Neglén
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005268:Femoral Vein / Q000000981:diagnostic imaging*; D006801:Humans; D007084:Iliac Vein / Q000000981:diagnostic imaging*; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D011152:Popliteal Vein / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D018616:Ultrasonography, Doppler, Duplex / Q000379:methods*; D020246:Venous Thrombosis / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: Deep venous thrombosis (DVT); Duplex ultrasound; Iliofemoral DVT; Proximal DVT thrombus extent; Thrombus location