title: A follow-up study of the fate of small asymptomatic deep venous thromboses.
abstract: BACKGROUND
  Postoperative asymptomatic deep venous thromboses (ADVT) can give rise to posttthrombotic syndrome (PTS), but there are still many unresolved issues in this context. For example, there is a lack of knowledge regarding the fate of small ADVT following minor orthopedic surgery. This follow-up study evaluates postthrombotic changes and clinical manifestations of PTS in a group of patients with asymptomatic calf vein DVT after surgery for Achilles tendon rupture.
  
  
  METHODS
  Forty-six consecutive patients with distal ADVT were contacted and enrolled in a follow-up consisting of a single visit at the hospital at a mean time of 5 years postoperatively, including clinical examination and scoring, ultrasonography and venous plethysmography. All patients had participated in DVT-screening with colour duplex ultrasound (CDU) 3 and 6 weeks postoperatively and 80% of them were treated with anticoagulation.
  
  
  RESULTS
  With CDU postthrombotic changes and deep venous reflux were detected at follow-up in more than 50% of the patients, more commonly in somewhat larger calf DVT:s initially affecting more than one vessel. However, only about 10% of the patients had significant venous reflux according to venous plethysmography. No patient had plethysmographic evidence of remaining outflow obstruction, but presence of postthrombotic changes shown with CDU negatively influenced venous outflow capacity measured with plethysmography. A clinical entity of PTS was rarely found and occurred only in two patients (4%) and then classified by Villalta scoring as of mild degree with few clinical signs of disease. Distal ADVT:s detected in the early postoperative period (3 weeks) showed DVT-progression in 75% of the limbs that were still immobilized and without anticoagulation.
  
  
  CONCLUSIONS
  Asymptomatic postoperative distal DVT:s following surgery for Achilles tendon rupture have a good prognosis and a favourable clinical outcome. In our material of 46 patients the general appearance of the clinical entity of PTS at 5 years follow-up was low (<5%). Morphological and functional abnormalities were mainly seen in those patients that initially had somewhat larger distal DVT:s involving more than one deep calf vein segment.
authors.affiliation: Department of Clinical Science and Education, Karolinska Institutet, Södersjukhuset, SE-118 83 Stockholm, Sweden. stefan.rosfors@sodersjukhuset.se.
authors.forename: Stefan
authors.initials: S
authors.lastname: Rosfors
authors.forename: Lena M
authors.initials: LM
authors.lastname: Persson
authors.forename: Gerd
authors.initials: G
authors.lastname: Lärfars
authors.forename: Lasse J
authors.initials: LJ
authors.lastname: Lapidus
references.citation: J Thromb Haemost. 2009 May;7(5):879-83
references.pmid: 19175497
references.citation: Clin Sci (Lond). 2000 Apr;98(4):449-54
references.pmid: 10731480
references.citation: Ann Intern Med. 2008 Nov 18;149(10):698-707
references.pmid: 19017588
references.citation: Eur J Vasc Endovasc Surg. 2006 Aug;32(2):217-21
references.pmid: 16546415
references.citation: J Vasc Surg. 1995 Nov;22(5):558-67
references.pmid: 7494356
references.citation: J Orthop Trauma. 2007 Jan;21(1):52-7
references.pmid: 17211270
references.citation: Blood Rev. 2002 Sep;16(3):155-65
references.pmid: 12163001
references.citation: Thromb Haemost. 2005 Feb;93(2):236-41
references.pmid: 15711738
references.citation: Angiology. 1992 Mar;43(3 Pt 1):219-28
references.pmid: 1533497
references.citation: J Orthop Surg (Hong Kong). 2005 Aug;13(2):113-9
references.pmid: 16131671
references.citation: Arch Intern Med. 2004 Jan 12;164(1):17-26
references.pmid: 14718318
references.citation: Am J Orthop (Belle Mead NJ). 2006 Oct;35(10):469-72
references.pmid: 17131737
references.citation: J Thromb Haemost. 2006 Apr;4(4):807-12
references.pmid: 16634750
references.citation: Eur J Vasc Endovasc Surg. 2005 Oct;30(4):404-14
references.pmid: 16009579
references.citation: Clin Sci (Lond). 1999 Mar;96(3):271-7
references.pmid: 10029563
references.citation: J Vasc Surg. 2004 Dec;40(6):1248-52
references.pmid: 15622385
references.citation: Int Angiol. 1992 Jul-Sep;11(3):160-4
references.pmid: 1460348
references.citation: Chest. 2004 Sep;126(3 Suppl):338S-400S
references.pmid: 15383478
references.citation: J Vasc Surg. 1995 Nov;22(5):524-31
references.pmid: 7494350
references.citation: J Vasc Surg. 1998 Jul;28(1):67-73; discussion 73-4
references.pmid: 9685132
references.citation: J Thromb Haemost. 2009 May;7(5):884-8
references.pmid: 19320818
references.citation: Circulation. 1992 Aug;86(2):414-9
references.pmid: 1638710
references.citation: Haematologica. 1995 Mar-Apr;80(2 Suppl):42-8
references.pmid: 7628770
references.citation: Int Angiol. 1992 Apr-Jun;11(2):127-31
references.pmid: 1402216
references.citation: Eur J Vasc Endovasc Surg. 2001 Nov;22(5):448-55
references.pmid: 11735184
references.citation: Ann Intern Med. 2004 Aug 17;141(4):249-56
references.pmid: 15313740
references.citation: Eur J Vasc Endovasc Surg. 1995 Nov;10(4):398-404
references.pmid: 7489207
references.citation: J Vasc Surg. 1996 Nov;24(5):738-44
references.pmid: 8918317
references.citation: Semin Vasc Surg. 2001 Sep;14(3):215-21
references.pmid: 11561283
references.citation: J Vasc Surg. 2003 Oct;38(4):793-8
references.pmid: 14560232