Therapeutic Options for Thromboprophylaxis
Depending on the level of patient risk for thromboembolism, the following therapies can be used alone or in combination as options for the prevention of deep vein thrombosis (DVT) in the surgical setting:
- Mechanical (nonpharmacologic) therapies – early ambulation, graduated compression stockings (GCS), and intermittent pneumatic compression (IPC)
- Pharmacologic agents – low-dose unfractionated heparin (LDUH) and low molecular weight heparin (LMWH)
Defining Risk Levels
Patient-specific predisposing factors increase the risk of DVT in patients undergoing urologic surgery. These factors are wide ranging and include immobility, trauma, malignancy, previous cancer therapy, past history of DVT, increasing age, pregnancy, estrogen therapy, obesity, smoking, and venous varicosities; these as well as additional factors increasing the risk of DVT are listed in Table 1 below.
Table 1: Risk Factors for Increased Development of Deep Vein Thrombosis
Surgery
Trauma (major or lower extremity)
Immobility, paresis
Malignancy
Cancer therapy (hormonal, chemotherapy, or radiotherapy)
Previous Venous Thromboembolism
Increasing age
Pregnancy and the postpartum period
Estrogen-containing oral contraception or hormone replacement therapy
Selective estrogen receptor modulators
Acute medical illness
Heart or respiratory failure
Inflammatory bowel disease
Nephrotic syndrome
Myeloproliferative disorders
Paroxysmal nocturnal hemoglobinuria
Obesity
Smoking
Varicose veins
Central venous catheterization
Inherited or acquired thrombophilia
|
Adapted with permission from Geerts, W.H., Pineo, G.F., Heit, J.A., et al.: Prevention of venous thromboembolism. Chest 2004; 126: 338S-400S.
When assessing the risk of DVT for an individual patient, both the procedure, with its inherent risk, and the patient's specific, predisposing factors must be considered. The appropriate DVT prophylaxis for a low-risk procedure may be more complex in a patient with a high-risk profile. A risk stratification table has been constructed to provide guidance in choosing the appropriate preventative measures (see Table 2 below).
Table 2: Patient Risk Stratification
| Low Risk |
Minor* surgery in patients <40 years with no additional risk factors |
| Moderate Risk |
Minor* surgery in patients with additional risk factors
Surgery in patients aged 40-60 years with no additional risk factors
|
| High Risk |
Surgery in patients >60 years
Surgery in patients aged 40-60 years with additional risk factors (prior venous thromboembolism, cancer, hypercoagulable state, see Table 1 in the original guideline document)
|
| Highest Risk |
Surgery in patients with multiple risk factors (age >40 years, cancer, prior venous thromboembolism) |
* For the purposes of this paper, minor surgery is defined as a procedure with a relatively short operating time in which the patient is rapidly ambulatory. Adapted with permission from Geerts, W.H., Pineo, G.F., Heit, J.A., et al.: Prevention of venous thromboembolism. Chest 2004; 126: 338S-400S.
Transurethral Surgery
For the vast majority of transurethral procedures, early ambulation is recommended for DVT prophylaxis. For patients at increased risk of DVT undergoing transurethral resection of the prostate (TURP), the use of GCS, IPC, postoperative LDUH or LMWH may be indicated.
Anti-Incontinence and Pelvic Reconstructive Surgery
The prevention of DVT in patients undergoing anti-incontinence and pelvic reconstructive surgeries should be dictated by preoperative individual patient risk factors and procedure-specific risk factors for DVT formation.
- For low-risk patients undergoing minor procedures the use of early postoperative ambulation appears to be sufficient.
- For moderate-risk patients undergoing higher risk procedures, the use of IPC, LDUH, or LMWH should be utilized.
- For high-risk and highest-risk patients undergoing higher-risk procedures, combination therapy with IPC plus LDUH or LMWH should be utilized unless the bleeding risk is considered unacceptably high.
Urologic Laparoscopic and/or Robotically Assisted Urologic Laparoscopic Procedures
In view of the lack of large randomized controlled trials (RCTs) addressing this issue as well as the concerns for increased retroperitoneal bleeding at the time of urologic laparoscopic procedures, the Panel recommends the use of IPC devices at the time of the laparoscopic procedure. High-risk groups which may require the use of LDUH and LMWH may be identified.
Open Urologic Surgery
The Panel recommends the use of IPC in patients undergoing open urologic procedures. Given the increased risk factors within this patient population, in many patients undergoing open urologic procedures, more aggressive regimens combining the use of IPC with pharmacologic prophylaxis may be considered.
Venous Thromboembolism (VTE) Prophylaxis Recommendations
| Level of Risk |
Prophylactic Treatment |
| Low Risk |
No prophylaxis other than early ambulation |
| Moderate Risk |
- Heparin 5000 units every 12 hours subcutaneous starting after surgery
- OR *Enoxaparin 40 mg (Cr Cl < 30 ml/min = 30 mg) subcutaneous daily
- OR Pneumatic compression device if risk of bleeding is high
|
| High Risk |
- Heparin 5000 units every 8 hours subcutaneous starting after surgery
- OR *Enoxaparin 40 mg (Cr Cl < 30 ml/min = 30 mg) subcutaneous daily
- OR Pneumatic compression device if risk of bleeding is high
|
| Very High Risk |
- *Enoxaparin 40 mg (Cr Cl < 30 ml/min = 30 mg) subcutaneous daily and adjuvant pneumatic compression device, or
- Heparin 5000 units every 8 hours subcutaneous starting after surgery and adjuvant pneumatic compression device
|
*Guidelines and Cautions for Enoxaparin Use
- In patients with a body weight > 150 Kg consider increasing prophylaxis dose of Enoxaparin to 40 mg subcutaneous every 12 hours.
- Withhold Enoxaparin generally for at least 2 to 3 days after major trauma, and then only consider use after review of current patient condition and risk benefit ratio.
- For planned manipulation of an epidural or spinal catheter (insertion, removal), Enoxaparin should be avoided/held for 24 hours BEFORE planned manipulation and should be resumed no earlier than 2 hours FOLLOWING manipulation.
- Special testing may be indicated for Enoxaparin in a patient with a history of heparin-induced thrombocytopenia.
- The risks of bleeding must be weighed against the benefits of prophylaxis in determining the timing of initiation of DVT pharmacologic prophylaxis in combination with mechanical prophylaxis.
In selected very high-risk patients, clinicians should consider post-discharge Enoxaparin or Warfarin.
Abbreviations: mg, milligram; Cr Cl, creatinine clearance; ml, milliliter; min, minute; Kg, kilogram
Conclusion
DVT prophylaxis should be considered in all patients undergoing urologic surgical procedures. In many patients undergoing low-risk procedures, early ambulation may be the only DVT prophylactic measure that is indicated. However, in patients with a high-risk profile undergoing a high-risk procedure, an assessment of all risk factors inherent to the patient and planned procedure should dictate the appropriate DVT prophylaxis. Future randomized trials comparing the different pharmacologic interventions would be useful and should be developed; the economics of thromboprophylaxis also should be evaluated.
