Deep Venous Thrombosis (DVT) – Overview

Discussion

• thromboembolism is among the most serious complications in orthopedics
• classic "Vichow's" triad
  • damage to venous endothelium
  • venous stasis
  • hypercoagulable states and conditions

Prevalence

• varies depending on the sensitivity of the study and the degree of prophylaxis
• theoretically every surgery patient probably develops microscopic thrombi which embolize to the lungs, but these may not be clinically relevant
• in the literature, the prevalence varies between 30-50% of patients will develop DVT following major orthopaedic procedures
• in one study of 100 TKR patients, there was a 7% occurance of proximal DVT, and a 20% occurance of distal DVT (Grady-Benson, et al (1994))
• in a total hip arthroplasty study by Colwell, et al (1999), the overall rate of throboembolic disease was 3.6% for patients receiving lovenox versus 3.7 % for patients receiving adjusted dose Coumadin
• about 8% of patient will develop some signs of PE (depending on extent of prophylaxis)
  • note that in patients that receive some form of DVT prophylaxis, the majority of DVT which do occur, will form in the calf vessels, and only 5% will form in the proximal veins
• note that ultrasound is very poor at picking up popliteal clots
• thrombi develop at the time of surgery in most cases, and the risk of PE is directly related to the the size of the clot and clot extension into the proximal vessels
  • about 20% of calf thrombi can be expected to propagate into the proximal vessels
  • mortality for pulmonary embolism may approach 10%
• the precise features and prognosis of DVT is dependent on the cause
• references
  • Postoperative surveillance for deep venous thrombosis with duplex ultrasonography after total knee arthroplasty.
  • Comparison of enoxaparin and warfarin for the prevention of venous thromboembolic disease after total hip arthroplasty. evaluation during hospitalization and three months after discharge.

Is prophylaxis necessary following major procedures?

• risk of postphlebitic syndrome
  • post thrombotic syndrome occurs due to vein dilitation and damage to vein valves
  • even patients with asymptomatic DVT may develop symptomatic venous congestion (58% of patients vs 38% of patients w/o DVT)
  • patients who develop postphlebitic syndrome may complain of venous congestion years after surgery
  • clinical signs of post thrombotic syndrome include leg swelling, pain, and venous stasis ulcers
• risk of PE
  • the answer seems obvious, but there is surprisingly little data to document that prophylaxis against DVT actually prevents fatal PE
  • this is especially true, now that more recent studies have documented that the mortality from postoperative DVT is rare
  • reference Prevention of venous thromboembolism
• without prophylaxis
  • 45-57% of THA will have DVT (23-36% proximal)
  • up to 30% of THA will have PE
  • 40-84% of TKA will have DVT (9-20% proximal)
  • up to 7% of TKA will have PE
  • mortality of PE in total joint population 3-6%
  • references
    • Thrombophylaxis in elective orthopaedic surgery - what is the purpose?
    • Long term clinical observations and venous functional abnormalities after asymptomatic venous thrombosis following total hip and knee arthroplasty.
    • Does total hip arthroplasty predispose to chronic venous insufficiency?
    • Postphlebitic syndrome after hip arthroplasty: 43 patients followed at least 5 years.

References

• A non-interventional comparison of rivaroxaban with standard of care for thromboprophylaxis after major orthopaedic surgery in 17,701 patients with propensity score adjustment.
• The use of novel oral anticoagulants for thromboprophylaxis after elective major orthopedic surgery.
• Benefit-to-harm ratio of thromboprophylaxis for patients undergoing major orthopaedic surgery. A systematic review.
• Complication rates after hip or knee arthroplasty in morbidly obese patients.
• New anticoagulants for thromboprophylaxis after total knee arthroplasty.
• Comparative safety and efficacy of antithrombotics in the management of venous thromboembolism after knee or hip replacement surgery: focus on rivaroxaban.
• The efficacy and safety of rivaroxaban for venous thromboembolism prophylaxis after total hip and total knee arthroplasty.
• Incidence of neuraxial haematoma after total hip or knee surgery: RECORD programme (rivaroxaban vs. enoxaparin).
• Elective hip and knee arthroplasty and the effect of rivaroxaban and enoxaparin thromboprophylaxis on wound healing.
• Efficacy and safety of rivaroxaban or fondaparinux thromboprophylaxis in major orthopedic surgery: findings from the ORTHO-TEP registry.
• Cost and outcomes associated with rivaroxaban vs enoxaparin for the prevention of postsurgical venous thromboembolism from a US payer's perspective.
• Oral rivaroxaban for the prevention of symptomatic venous thromboembolism after elective hip and knee replacement.
• Antithrombotic prophylaxis in major orthopaedic surgery: an historical overview and update of current recommendations.

Risks based on specific procedures

• total hip replacement (THA)
• total knee replacement (TKA)
• trauma and fractures
• hip fracture and surgery
  • in elective hip surgery there is three-fold decrease in thromboembolic complications from the use of regional anesthesia and graded compression stockings
• elective spine surgery
  • risk of DVT may be less than is seen w/ other orthopaedic procedures
  • consider use of intermittent compression stockings w/o use of anticoagulant agents

Prognosis of cancer with venous thromboembolism

• in the study by Sorensen HT, et al, the authors studied the prognosis of survival of patients who received a diagnosis of cancer at the same time as or after an episode of venous thromboembolism
  • their survival was compared w/ that of patients with cancer who did not have DVT (control patients), who were matched in terms of type of cancer, age, sex, and year of diagnosis
  • of 668 patients who had cancer at the time of an episode of DVT, 44.0 % of those with data on the spread of disease (563 patients) had distant metastasis, as compared with 35.1 % of 5371 control patients
  • in the group with cancer at the time of DVT, the one-year survival rate was 12 %, as compared with 36 % in the control group (P<0.001), and the mortality ratio for the entire follow-up period was 2.20 (95 % CI, 2.05 to 2.40)
  • patients in whom cancer was diagnosed within one year after an episode of venous thromboembolism had a slightly increased risk of distant metastasis at the time of the diagnosis (prevalence ratio, 1.23 and a relatively low rate of survival at one year (38% vs. 47% in the control group; p < 0.001)
  • cancer diagnosed at the same time as or within one year after an episode of venous thromboembolism is associated with an advanced stage of cancer and a poor prognosis
  • reference Prognosis of Cancers Associated with Venous Thromboembolism

(see also: Coagulation Cascade; Pulmonary Embolus)

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