title: The nonsaphenous vein of the popliteal fossa: prevalence, patterns of reflux, hemodynamic quantification, and clinical significance.
abstract: BACKGROUND
  A large tortuous vein coursing over the posterior aspect of the knee and the upper calf may give rise to a constellation of varicose veins unrelated to the great (GSV) or small (SSV) saphenous veins. Designated the popliteal fossa vein (PFV), it perforates the deep popliteal fascia and empties into the deep system. We examined the prevalence, anatomic reflux patterns, hemodynamic role, and clinical significance of the PFV.
  
  
  METHODS
  We examined 543 patients (818 limbs) with venous disease, aged 14 to 94 years (median, 55 years). The study consisted of group A, comprising limbs with a PFV, and group B, formed by the remaining limbs. The history, clinical examination, and venous duplex scan findings were analyzed retrospectively. Venous clinical severity and venous segmental disease scores of group A were compared with those of an equal number of CEAP-, sex-, and age-matched control limbs. In situ venous hemodynamics of the PFV obtained with duplex scan are reported.
  
  
  RESULTS
  A PFV was found in 24 (2.93%) of 818 limbs (95% confidence interval [CI], 1.8%-4.1%); 24 (4.4%) of 543 subjects (95% CI, 2.7%-6.2%), 12 men and 12 women aged 23 to 82 years (median, 54 years) had a PFV. CEAP clinical classes in limbs with a PFV were as follows: C2, 15 limbs; C3, 5 limbs; C4, 2 limbs; C5, 1 limb; and C6, 1 limb. Proximal and distal (92%), superficial (100%), perforator (87.5%), and complex-pattern (41.7%) reflux occurred more often in group A (P < .01). Incompetence in the GSV (75%), posterior arch, and posteromedial and saphenous tributaries was also more frequent in group A (P < .05). SSV reflux in group A (29%) matched that in group B. The PFV terminated at the deep system (96% in the popliteal vein) above the SSV (median distance, 1.5 cm; 95% CI, 0.5-2 cm). The odds ratio for a PFV in limbs with prior SSV disconnection was 5.68. Deep reflux was evenly distributed in group A (41.7%) and group B (27%). The prevalence of incompetent perforators was 283% (95% CI, 194%-373%) in group A and 96% (95% CI, 95%-98%) in group B (P < .001). PFV tributaries were distributed at the popliteal area (100%); the posterior (87.5%), medial (62.5%), and lateral (37.5%) upper calf; and the posterior distal thigh (17%), often projecting to the posterior GSV arch (50%). The (median) peak velocity of reflux in the PFV was 82.6 cm/s, the mean velocity was 17.7 cm/s, the duration was 2.4 seconds, the volume flow was 231.5 mL/min, and the expelled volume was 9.3 mL. The median diameter of the PFV at the crossing of the fascia was 0.527 cm. Venous clinical severity (range, 2-17; median, 5.5) and venous segmental disease (range, 0.5-8; median, 2.75) scores in limbs with a PFV exceeded (P <or= .04) those of the control limbs.
  
  
  CONCLUSIONS
  With a prevalence of 4.4%, the PFV presents in limbs featuring complex reflux patterns involving all three venous systems proximally and distally. Limbs with a PFV have a higher propensity for GSV and superficial tributary reflux and have perforator vein incompetence three times more often than limbs without this vein. The PFV perforates the deep popliteal fascia terminating at the deep system (ie, the popliteal vein in 96%) distinctly above the SSV. In light of its reflux dynamics, nearing or exceeding those of severely impaired perforator veins, and the complex patterns of reflux (venous segmental disease) and venous clinical severity (high venous clinical severity scores) of the affected limbs, clinical and investigational awareness of the PFV is warranted.
authors.affiliation: St Mary's Hospital, London, United Kingdom. k.delis@ic.ac.uk
authors.forename: Konstantinos T
authors.initials: KT
authors.lastname: Delis
authors.forename: Alison L
authors.initials: AL
authors.lastname: Knaggs
authors.forename: John T
authors.initials: JT
authors.lastname: Hobbs
authors.forename: Marianne A
authors.initials: MA
authors.lastname: Vandendriessche
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007717:Knee / Q000098:blood supply; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D011152:Popliteal Vein / Q000033:anatomy & histology; D012501:Saphenous Vein / Q000033:anatomy & histology; D018615:Ultrasonography, Doppler, Color; D014648:Varicose Veins / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology