What is the recommended venous thromboembolism (VTE) prophylaxis for patients undergoing radical prostatectomy (RP) without extended lymph node dissection (eLND)?

VTE Prophylaxis After Radical Prostatectomy Without Extended Lymph Node Dissection

For patients undergoing radical prostatectomy without extended lymph node dissection (eLND), mechanical prophylaxis with sequential compression devices and early ambulation is sufficient for most patients, with pharmacologic prophylaxis reserved only for those with additional high-risk factors (age >75, BMI >35, personal history of VTE, or VTE in first-degree relative).

Risk Stratification Framework

The baseline VTE risk after RP without eLND is substantially lower than procedures requiring extended prophylaxis:

• Robotic RP without PLND: 0.2-0.9% VTE risk in low-risk patients 1
• Open RP without extended PLND: 0.4-0.8% VTE risk in low-risk patients 2
• Bleeding risk with pharmacologic prophylaxis: 0.1-1.0% across all RP approaches 1

This contrasts sharply with radical cystectomy (2.6-11.6% VTE risk) where extended prophylaxis is clearly warranted 3.

Evidence-Based Approach by Patient Risk Category

Low-Risk Patients (No Additional Risk Factors)

Mechanical prophylaxis only:

• Sequential compression devices from operating room entry until complete ambulation 4
• Well-fitted graduated compression stockings 5
• Aggressive early mobilization on postoperative day 1 4

A large series of 1,364 RRPs using only mechanical prophylaxis demonstrated a VTE rate of just 0.21% with no pulmonary emboli or VTE-related deaths 4. This supports avoiding routine pharmacologic prophylaxis in standard-risk patients.

High-Risk Patients (≥1 Risk Factor Present)

Add pharmacologic prophylaxis when:

• Age >75 years 2
• BMI >35 2
• Personal history of VTE 2
• VTE in first-degree relative 2

Dosing regimen:

• Enoxaparin 40 mg subcutaneously once daily, starting 6-8 hours postoperatively 6
• Continue during hospitalization (typically 7-10 days) 5
• Do NOT extend beyond hospital discharge for RP without eLND 2, 1

Key Distinctions from Radical Cystectomy

The evidence provided focuses heavily on radical cystectomy, where extended 4-week prophylaxis is standard of care because >50% of VTEs occur post-discharge 3. However, this does NOT apply to RP without eLND:

• RP without eLND has 5-10 times lower VTE risk than cystectomy 1
• The net benefit calculation for extended prophylaxis is "negligible or possibly harmful" in low-risk RP patients 2
• Extended prophylaxis should only be considered when RP includes extended PLND (not the scenario in this question) 2, 1

Safety Considerations for Pharmacologic Prophylaxis

When pharmacologic prophylaxis is used:

Contraindications to LMWH:

• Active major bleeding 3
• Thrombocytopenia with positive antiplatelet antibodies or history of heparin-induced thrombocytopenia 3
• Age ≥90 years with creatinine clearance <60 ml/min 3

Precautions:

• INR >1.5 3
• Uncontrolled hypertension (SBP >200 or DBP >110 mmHg) 3
• Creatinine clearance <30 ml/min: reduce enoxaparin to 30 mg once daily 5

Timing with neuraxial anesthesia:

• Avoid LMWH 12 hours before epidural/spinal catheter manipulation 3
• May administer 2 hours after catheter removal 3

Common Pitfalls to Avoid

• Over-extrapolating cystectomy data to RP: The extensive evidence for 4-week extended prophylaxis in cystectomy 3 does not apply to RP without eLND due to fundamentally different risk profiles 2, 1

• Routine pharmacologic prophylaxis in all patients: A 1997 study showed 7% wound hematoma/lymphocele rate with routine LMWH versus 0% without, concluding routine use is not supported 7

• Ignoring the bleeding risk: With VTE rates of 0.2-0.9% and bleeding rates of 0.1-1.0%, the risk-benefit ratio is narrow and tips negative in low-risk patients 1

• Assuming laparoscopic/robotic approach eliminates VTE risk: While lower than open surgery, robotic RP still carries 0.2-0.9% VTE risk requiring mechanical prophylaxis 1