Venous Thromboembolism Prophylaxis

Patient Risk Factors and Stratification

Adult patients undergoing open urologic surgery are at risk for development of deep vein thrombosis (DVT) and subsequent pulmonary thromboembolism (PTE), with age >60 years alone placing a patient in the high-risk category, as recommended by the American Urological Association (AUA) 1
Recent major abdominal surgery, such as open laparotomy, and reduced mobility following surgery are risk factors for venous thromboembolism (VTE) 1, 2
Patient-specific risk factors that increase DVT risk include age >40 years, prior history of VTE, cancer, obesity, pregnancy/estrogen therapy, and immobility, as stated by the American Urological Association 1
The Caprini Risk Assessment Model categorizes thrombosis risk as Very low (0 points; 0.5%), Low (1-2 points; 1.5%), Moderate (3-4 points; 3%), and High (≥5 points; 6%) according to the American College of Physicians, as reported by the Mayo Clinic Proceedings 3
The Padua score (high risk ≥4 points) and the IMPROVE VTE Risk Assessment Model (RAM) (increased risk ≥2 points) are validated tools for assessing the risk of deep vein thrombosis, as recommended by the American College of Chest Physicians and the American Society of Hematology 4, 5, 6

Patients undergoing laparotomy, laparoscopy, or thoracotomy lasting greater than 30 minutes should receive pharmacologic thromboprophylaxis with either low-dose unfractionated heparin (UFH) or low molecular weight heparin (LMWH) unless contraindicated, as recommended by the American Society of Clinical Oncology (ASCO) 2
Low-dose unfractionated heparin (LDUH) 5,000 units subcutaneously every 8 hours should be started within 24 hours postoperatively to provide early protection against VTE formation 2
Intermittent pneumatic compression (IPC) devices should be applied to both legs immediately after surgery and used continuously until the patient is fully ambulatory, as recommended by the American Urological Association (AUA) 1, 7
Low molecular weight heparin (LMWH) is the preferred pharmacological agent for VTE prophylaxis in hospitalized patients due to its superior efficacy, safety profile, and once-daily dosing convenience, as recommended by the American College of Physicians and the American College of Surgeons 3, 8
Recommended LMWH regimens include:
Unfractionated heparin (UFH) can be administered at a dose of 5000 U subcutaneously three times daily, as recommended by the American College of Physicians and the National Comprehensive Cancer Network 3

Postoperative initiation of prophylaxis within 24 hours is appropriate to balance bleeding and thrombosis risks in emergency surgery cases, as recommended by the American Society of Clinical Oncology (ASCO) 2
Early ambulation should be encouraged as soon as clinically appropriate, but should not replace pharmacological and mechanical prophylaxis, as recommended by the American Urological Association (AUA) 7
Prophylaxis should be continued for at least 7-10 days postoperatively, and for high-risk patients, consider extending prophylaxis for up to 4 weeks, as recommended by the American Society of Clinical Oncology (ASCO) 2
The minimum duration of prophylaxis is 10-14 days, with consideration of up to 35 days for high-risk patients, as recommended by the American College of Physicians, as reported by the Mayo Clinic Proceedings 3
Extended prophylaxis for 4 weeks is recommended after major abdominal or pelvic cancer surgery for high-risk patients, supported by meta-analyses showing reduced postoperative VTE risk, as stated by the American Society of Clinical Oncology and the American College of Chest Physicians 10, 15, 11, 6, 9

Cancer patients are at higher risk of VTE, and those with high-risk cancer types (e.g., pancreatic, lung, or gastrointestinal cancer) may require more aggressive prophylaxis, as recommended by the American Society of Clinical Oncology (ASCO) 10, 15, 11
High-risk outpatients starting systemic chemotherapy may be offered prophylaxis with apixaban, rivaroxaban, or LMWH if no significant bleeding risk exists, according to the National Comprehensive Cancer Network 11
Neurosurgery patients should receive LMWH or UFH recommended postoperatively, according to the Congress of Neurological Surgeons 15
Non-surgical brain tumor patients should not receive primary pharmacological prophylaxis, as recommended by the American Brain Tumor Association 15
Active bleeding, severe thrombocytopenia (platelets <25×10⁹/L), recent intracranial hemorrhage, and heparin-induced thrombocytopenia are contraindications to pharmacological thromboprophylaxis, as stated by the American College of Chest Physicians and the American Society of Hematology 16

The risk of bleeding should be assessed using the IMPROVE Bleeding RAM (high bleeding risk ≥7 points), as recommended by the American College of Chest Physicians 6
Mechanical prophylaxis, such as intermittent pneumatic compression (IPC) or graduated compression stockings (GCS), should not be used as monotherapy unless pharmacological methods are contraindicated due to active bleeding or high bleeding risk, as recommended by the American Society of Clinical Oncology and the American College of Chest Physicians 17, 2, 11, 6
For patients with high bleeding risk, mechanical prophylaxis (IPC) alone may be used until bleeding risk decreases, as recommended by the American College of Physicians, as reported by the Mayo Clinic Proceedings 3

Prophylaxis should be continued throughout hospitalization and until the patient is fully mobile or discharged, as recommended by the Society of Hospital Medicine and the American College of Chest Physicians 3, 6
High-risk patients undergoing major abdominal or pelvic surgery should receive extended prophylaxis for up to 28-35 days post-discharge, as suggested by the American College of Surgeons 3
Routine ultrasound screening is not recommended for asymptomatic critically ill patients, as stated by the American College of Chest Physicians 6