DVT / PE

 

Goal

 

Minimize symptomatic DVT / PE while limiting postoperative bleeding

 

Options

 

Mechanical compression - graduated stockings, pneumatic compression, foot pumps

Aspirin

Low molecular weight heparin (LMWH)

Oral factor Xa inhibitors - Rivaroxaban, Apixaban

Warfarin - usually used for treatment

 

Contraindications to chemoprophylaxis

 

Active bleeding

High risk bleeding

- hemophilia

- thrombocytopenia - platelets < 50

- history GI bleeding

Severe hepatic disease (INR < 1.3)

Renal impairment

- must adjust LMWH and oral factor Xa inhibitor doses

History of HITT (heparin induced thrombocytopenia)

Recent neurosurgery or eye surgery

 

Spinal anesthesia

 

Queensland Health Guidelines for Prevention of DVT

 

LMWH

- prophylaxis 12 hours after insertion

- typically withhold for 4 - 6 hours after removal

 

Oral Factor Xa inhibitors

- 24 hours minimum after insertion

- 6 hours after withdrawal

 

Timing

 

Queensland Health Guidelines for Prevention of DVT

 

Onset

 

Hemostasis obtained

 

Heparin / LMWH - 12 hours post op

 

Oral factor Xa inhibitors

- Rivaroxaban 6 - 10 hours post op

- Dabigatran 4 hours postop

- Apixaban 12 - 24 hours post op

 

Duration

 

TKA - 10 - 14 days

THA - 4 - 5 weeks

 

Low Molecular Weight Heparin (LMWH)

 

Definition Types Mechanism Advantage Disadvantage

Fractionated heparin

Molecular weight < 5000

Enoxeparin / Clexane

- 0.5 mg/kg od

- 40 mg od

 

Dalteparin / Fragmin

- 5000IU od

Antifactor Xa

Longer half life than heparin

Decreased bleeding due to reduced platelet effect

No monitoring required

Antidote: Protamine sulfate

Given by injection

Reduce dose with low GFR

Increase dose BMI > 40

Difficult to reverse

HITT

 

Direct oral Factor Xa inhibitors

 

Definition Types Mechanism Advantage Disadvantage
Act directly on Factor X

Rivaroxaban 10 mg od

 

Apixaban 2.5 mg bid

 

Dabigatran 220 mg od

Factor Xa inhibitor

Oral dosing

No monitoring required

Interact with statins

 

Aspirin

 

Definition Types Mechanism Advantage Disadvantage

Acetylsalicyclic acid

Aspirin 80 - 300mg

COX inhibitor

Oral form

No monitoring required

GI bleeding / stomach upset

 

 

Mechanism

- irreversibly inhibits cyclo-oxygenase in platelets

- blocks thromboxane A2 formation

 

Results

 

Mechanical compression

 

Wong et al Hip Pelvis 2024

- 540 THA treated only with graduated stockings and pneumatic compression

- routine ultrasound day 4 and 7

- incidence proximal DVT 1%

 

Warfarin v LMWH

 

Hull et al Arch Int Med 2000

- RCT of 1000 THA of warfarin v dalteparin

- warfarin: DVT 24%, proximal DVT 1%, symptomatic DVT 4.5%

- dalteparin: DVT 13%, proximal DVT 1%, symptomatic DVT 1.5%

 

Aspirin v LMWH

 

CRISTAL study group JAMA 2022

- RCT 100mg aspirin v 40 mg enoxeparin / LMWH in 9711 THA and TKA patients

- symptomatic VTE in aspirin group was 3.5%

- symptomatic VTE in enoxeparin group was 1.8%

- no difference in mortality

 

Oral Factor Xa inhibitors versus LMWH

 

Eriksson et al NEJM 2008

- 4500 THA RCT to either rivaroxaban or enoxeparin

- enoxeparin: DVT/PE 3.7%, major bleeding 0.1%

- rivaroxaban: DVT/PE 1.1%, major bleeding 0.3%

 

Kasina et al CORR 2019

- Swedish registry

- 5,700 THA with oral anticoagulants: symptomatic DVT 0.3%, symptomatic PE 0.1%

- 27,000 LMWH: symptomatic DVT 0.6%, symptomatic PE 0.4%

- reduced risk of DVT / PE with oral factor Xa inhibitor

- no difference in bleeding

 

Lassen et al NEJM 2010

- 5400 THA RCT either apixaban or enoxeparin 35 days

- enoxeparin: DVT/PE 3.9%

- rivaroxaban: DVT/PE 1.4%

 

Aspirin versus Oral Factor Xa inhibitors

 

Anderson et al NEJM 2018

- 3500 patients

- rivaroxaban 5 days + aspirin 9 days TKA or 30 days THA

- rivaroxaban 14 days TKA or 30 days THA

- no difference DVT or major bleeding

 

Preoperative

 

Hull et al Arch Int Med 2000

- RCT of 1500 THA of warfarin v LMWH / dalteparin

- dalteparin given preoperatively had slightly decreased rates of total DVT but increased bleeding

 

Duration

 

Kakkar et al Lancet 2008

- RCT of 2500 THA patients

- 30 days of rivaroxaban v 14 days enoxeparin

- rivaroxaban: DVT 2%, PE 0.1%, bleeding 7%

- enoxeparin: DVT 8%, PE 0.5%, bleeding 6%