myths and facts dvt

THROMBOPROPHYLAXIS IN ARTHROPLASTY – MYTHS AND FACTS

Dr. Sushil Paudel

DVT PREVALENCE General surgery 35% Gynecologic Surgey 16% Hip Surgery 50 – 60% Knee reconstruction 40 – 84% Multi – system/Major trauma 50% Myocardial infarction 24% Neurosurgery 22% Spinal Cord Injury 67 – 100% Stroke 55%

ACCP 2001

MYTH 1DVT is fatal and decrease in incidence

of DVT reduces the chances of PE. Thus, DVT and PE are correlated.

DVT is not fatal(majority of them are asymptomatic). What matters is FATAL PE which may kill the patient.

Paul A Lotke, CORR, 2006

ARE DVT AND PE CORRELATED??

Although prophylactic agents affect the incidence of deep venous thrombosis (DVT), the rate of fatal PE remains the same

Sheth NP, Lieberman JR. DVT prohylaxis in Total joint reconstruction.Orthop .Clin N Am 41 (2010) 273–280.

MYTH 2Incidence of fatal PE after

arthroplasty is more than 1%.

Risk of fatal PE has been consistently reported over the past decade to be approximately 0.06% to 0.6%.

J Bone Joint Surg Br. 2009 May;91(5):645-8Cusick LA, Beverland DE.

Ansari S, Warwick D, Ackroyd CE, Newman JH.J Arthroplasty. 1997 Sep;12(6):599-602.

Coventry MB, Nolan DR, Beckenbaugh RD. J Bone Joint Surg [Am] 1973;55-A:1487-92. Johnson R, Green JR, Charnley J. Clin Orthop 1977;127:123-32.

Rate of fatal PE does not appear to vary with different regimens such as low molecular weight heparins (LMWHs), antithrombins, Coumadin, and aspirin or with compressive stockings

Sheth NP, Lieberman JR. DVT prohylaxis in Total joint reconstruction.Orthop .Clin N Am 41 (2010) 273–280.

MYTH 3Pharmacological prophylaxis

routinely recommended in THA/ TKA.

( ACCP, 2008)

No consensus exists regarding the optimal prophylaxis regimen against thromboembolic disease in orthopaedic patients

( AAOS, 2011)

THE GAP IN PROTECTION

50% of thrombi formation begins intraoperatively

The “Gap” in protection is when the patient is at risk for DVT, but the

administration of pharmacological prophylaxis cannot begin.

1. O’Meara and Kaufman. Prophylaxis for Venous Thromboembolism in Total Hip Arthroplasty: A Review. Orthopaedics. 1990 13(2):173-178

Due to concerns for the development of epidural hematoma, increased drain in TKR & THR patients, LMWH(pharmacological prophylaxis)is generally administered 12-24hrs post-op.

Since the period of highest risk for DVT is the first 24 hr period, this modality is not protecting the patients during the highest period of risk.

ONSET OF ACTIONNot only is LMWH many times not

administered until 12 – 24 hrs post –op, it does not become fully effective for upto 3-5 hrs.

LMWH 3 – 5 hrs Warfarin 72 – 96 hrs Mechanical

Immediate

LMWH – HARMFUL OR BENEFECIALConflicting reportsPro heparin reports have

focused only on presence or absence of DVT not on final outcome

Number of reports against LMWH use are gradually ON RISE with growing experience

There were more soft-tissue side effects in the patients who received enoxaparin than in those who used the foot pump: there was more bruising of the thigh and oozing of the wound (p < 0.001 for each), postoperative drainage (578 compared with 492 milliliters; p = 0.014), and swelling of the thigh (twenty compared with ten millimeters; p = 0.03). They concluded that the foot pump is a suitable alternative to low-molecular-weight heparin forprophylaxis against thromboembolism after total hip replacement and that it produces fewer soft-tissue side effects.

COMPLICATIONS OF PHARMACOLOGICAL PROPHYLAXIS

SystemicLocal

According to Salvati (JBJS Am, 2000): Risk of life threatening complications in Joint replacement are same

WITH or WITHOUT the use of LMWH

SYSTEMIC COMPLICATIONSBleeding Heparin induced thrombocytopeniaCVA – Hemorrh. & Thromb.MIRenal & Hepatic infarction & bleedingSubcutaneous necrosisEpidural hematoma, Poor post-op

analgesia!

LOCAL COMPLICATIONSInfection – 6 to 10 folds↑ Discharge – resulting in

increased wound drainWound hematoma↑ Local pain↑ swellingDelayed healing Marginal necrosisDecreased ROM

Use of anticoagulants requires balancing the risk of clots against the risk of bleeding.

Multimodal approach – closest to an ideal method of prophylaxis

ALTERNATIVES? Pneumatic leg compression

devices Foot compression devices Anti-embolism stockings

DVT PROPHYLAXIS GUIDELINES

GUIDELINES PREFERRED MECHANICAL PROHYLAXIS ONLY

International Consensus Statement (ICS) - 2006

Mechanical Yes

National Institute for Health and Clinical Excellence(NICE) - 2007

Mechanical Yes

American college of Chest Physicians(ACCP) - 2008

Anticoagulants No

Eighth ACCP-TJA

All primary THA and TKA patients are considered ‘‘high risk’’ regardless of patient age, activity level, and comorbidities.

LMWH*, warfarin (INR 2-3)*, fondaparinux*Up to 35 days for THA, hip fx The ACCP recommends against LDUH,

aspirin, dextran, TEDs, or venous foot pumps as only means of prophylaxis

*ACCP grade 1A. Geerts et al. Chest. 2008;133;381-453.

Orthopaedic surgeons response to 8th ACCP Guidelines

AAOS GuidelinesAmerican Academy of Orthopaedic

Surgeons Clinical Guideline on Prevention of Symptomatic Pulmonary Embolism in Patients Undergoing Total

Hip or Knee Arthroplasty

Strictly for PEDo not address DVT

The AAOS guidelines have rejected the use of venographically detected asymptomatic DVT as a valid outcome when assessing the efficacy of thromboprophylaxis in clinical studies, and instead consider fatal PE as only clinically relevant outcome

RECOMMENDATIONSNo routine post-op duplex USG (strong)Discontinue anti-platelet drugs before

surgery (Moderate)Use of neuraxial anaesthesia (moderate)Previous history of VTE should receive

both pharmacologic and mechanical prophylaxis.(consensus)

Assessment of known bleeding disorders like hemophilia, liver disease (Consensus)

Known bleeding disorder or liver disease should receive mechanical prophylaxis only. (consensus)

Early mobilization post surgery(consensus)Unable to recommend for or against IVC

filters(inconclusive)No routine assessment of risk factors other than

previous history (inconclusive)Use of pharmacologic and/or mechanical

compressive devices for prevention of VTE(moderate) but unable to recommend for or against any prophylaxis (Inconclusive)

CURRENT PRACTICE

• Better pain management allowing early mobilization• Less traumatic surgery• Regional aesthesia•Mechanical prophylaxis like foot/ calf pump, stockings in all patients.• Pharmacological prophylaxis in selected patients.

TAKE HOME MESSAGEDVT and PE are not relatedPE is fatal not DVTOptimal prophylaxis for DVT/PE is still

a mysteryLMWH should be used in highly

selected cases(history of VTE).Mechanical methods provides

immediate prophylaxis at the time of highest risk(within 24 hrs of surgery) without any significant complications.

THANK YOU