Levels of evidence (I–III) and recommendation grades (A–C) are defined at the end of the "Major Recommendations" field.
Risk Stratification
Operative Factors
Laparoscopic surgery of all types causes serum hypercoagualability of varying degrees (level I, II evidence). Shorter (less than one hour) and less complex laparoscopic procedures such as simple laparoscopic cholecystectomy probably have low risk of venous thromboembolism (VTE) disease (level III evidence). Longer/complex laparoscopic procedures such as laparoscopic roux-en-y gastric bypass are higher risk, (level II evidence). Although patient positioning may alter deep vein thrombosis (DVT) risk, there is not enough significant evidence to suggest that DVT prophylaxis should be changed based on body position alone.
Patient Factors
Age, immobility, history of venous thromboembolism, varicose veins, malignant disease, severe infection, chronic renal failure, more than three pregnancies, peri-pregnancy, congestive heart failure (CHF), history of myocardial infarction (MI), inflammatory bowel disease, hormone replacement therapy, oral contraceptive use, and obesity all increase risk (level II evidence). Inherited or acquired thrombophylias (e.g., protein C or S deficiency, factor V Leiden, antithrombin deficiency) greatly increase risk (level II evidence). A strong family history of clotting complications should be inquired about, and may also influence prophylactic treatment strategy.
Table 1 – Risk Factors for VTE (One Point Each)
| Procedure Specific |
Patient Specific |
Duration >1 hour
Pelvic procedure
|
History of VTE
Age >40
Immobility
Varicose veins
Cancer
Chronic renal failure
Obesity
Peri-partum
|
Congestive heart failure
Myocardial infarction
Hormone replacement therapy
Oral Contraceptive Use
Multiparity (3)
Inflammatory bowel disease
Severe infection
|
| For inherited or acquired thrombophilias hematology consult is recommended where available |
Prophylactic Methods
Unfractionated Heparin (low dose UH)
The dose is 5000 U given subcutaneously. This should be started within two hours of operation (evidence level II) and then every 8 or 12 hours. Every 8 hours is probably more effective at preventing VTE with similar risk of major bleeding (level II evidence). Continuous infusion of unfractionated heparin is as effective as the subcutaneous route but has an increased risk of major bleeding and also requires hematologic monitoring (level III evidence).
Low Molecular Weight Heparin (LMWH)
The dose and frequency for LMWH depends on the manufacturer, and should be used according to their recommendations, although patient weight may also be a factor. One trial showed a need for increased LMWH in the morbidly obese (level III evidence). LMWH is at least as effective as low dose UH with a similar risk of major bleeding (level I evidence). There is decreased dosing schedule and decreased risk of heparin induced thrombocytopenia with LMWH compared to UH. Most studies start dosing the night before surgery with no other preoperative dosing to decrease the risk of operative bleeding. One trial showed no increase of operative bleeding when given two hours preoperatively versus the night before (level I evidence). Special consideration needs to be given when using LMWH with epidural or spinal anesthesia because of the risk of causing hematoma during placement or removal of the catheter (level II evidence).
Pneumatic Compression Devices (PCD)
Calf length pneumatic compression devices seem to offer the same protection for VTE as LMWH or low dose heparin (level II evidence). Foot pneumatic compression devices increase lower extremity venous blood flow and cause fibrinolysis to the same extent as calf length devices and seem to have similar benefit to calf length (level III evidence). Foot compression devices are often used with obese patients because calf length may not fit properly. With pneumatic compression devices there is no increased risk of bleeding and therefore little risk of use. There are no data to support the use of PCDs on only one extremity or the upper extremities during laparoscopic surgery.
Combination Therapy
LMWH or low dose UH with PCDs may decrease the risk of VTE even more than the single line therapy (level II evidence).
Inferior Vena Cava (IVC) Filters
These have been used for high risk patients—patients with venous stasis disease, body mass index (BMI) >59, truncal obesity, and hypoventilation syndrome, or sleep apnea undergoing Roux-en-Y gastric bypass with good results (level III evidence). There are retrievable filters that can be placed peri-operatively and removed up to a year later or left in place. If filters are left in place, low dose coumadin or equivalent anticoagulation is recommended to prevent IVC thrombosis and pulmonary embolism caused by the filter (level III).
Compression Stockings, Coumadin
These are inferior methods for the prevention of VTE (level III evidence). Presumably, compression stockings do not create enough pressure to prevent stasis in the deep leg veins or alter lower extremity blood flow and fibrinolysis. The anticoagulative effect of coumadin alone starts too late to prevent DVT if given immediately prior to the surgical procedure.
Table 2 - Suggested VTE Prophylaxis
| Procedure |
Risk Factors |
Recommendation |
Level of Recommendation Level of Evidence |
| Laparoscopic Cholecystectomy |
0 or 1 |
None, PCDs, UH, or LMWH |
C; II, III |
| Laparoscopic Cholecystectomy |
2 or more |
PCDs, UH, or LMWH |
C; II, III |
| Laparoscopic Appendectomy |
0 or 1 |
None, PCDs, UH, or LMWH |
C; II, III |
| Laparoscopic Appendectomy |
2 or more |
PCDs, UH, or LMWH |
C; II, III |
| Diagnostic Laparoscopy |
2 or more |
PCDs, UH, or LMWH |
C; II, III |
| Laparoscopic Inguinal Hernia |
2 or more |
PCDs, UH, or LMWH |
C; II, III |
| Laparoscopic Nissen Fundoplication |
0 or 1 |
PCDs, UH, or LMWH |
B/II |
| Laparoscopic Nissen Fundoplication |
2 or more |
PCDs and UH or LMWH |
B/I, II |
| Splenectomy |
0 or 1 |
PCDs, UH, or LMWH |
B/II |
| Splenectomy |
2 or more |
PCDs and UH or LMWH |
B/II
|
| Other Major Laparoscopic Procedures: Roux-Y, etc |
0 or more |
PCDs and UH or LMWH |
B/III |
Abbreviations
- LMWH, low molecular weight heparin
- PCDs, pneumatic compression devices
- UH, unfractionated heparin
Length of Treatment
Length of treatment remains controversial. The guideline developers recommend treatment until patients are fully mobile or until discharge from the hospital, unless the patient has an acquired hypercoagulable state, then treatment for two weeks or more may be prudent (level III). Consultation with a hematologist may be helpful in determining an appropriate treatment strategy in these instances.
Contraindications
Contraindications to anticoagulation therapy for VTE prophylaxis will vary depending on the clinician's assessment of the risk-benefit ratio. The clinician should refer to individual manufacturer recommendations for specific therapy, and utilize sound clinical judgment regarding the decision to withhold prophylactic therapy.
Definitions:
Levels of Evidence
Level I - Evidence from properly conducted randomized, controlled trials
Level II - Evidence from controlled trials without randomization
Or
Cohort or case-control studies
Or
Multiple time series, dramatic uncontrolled experiments
Level III - Descriptive case series, opinions of expert panels
Recommendation Grading
Grade A - Based on high-level (level I or II), well-performed studies with uniform interpretation and conclusions by the expert panel
Grade B - Based on high-level, well-performed studies with varying interpretation and conclusions by the expert panel
Grade C - Based on lower level evidence (level II or less) with inconsistent findings and/or varying interpretations or conclusions by the expert panel
