**5.3 Dual prophylaxis**

178 Deep Vein Thrombosis

(Rabinov & Paulin, 1972). Currently, contrast venography is rarely indicated nowadays and has been replaced by the noninvasive measures. It is sometimes performed to confirm the diagnosis of a clinically suspected DVT. However, if noninvasive imaging is normal or inconclusive and still DVT is clinically suspected, venography is done to confirm the diagnosis. In the cases of clinical suspicion of DVT, a negative contrast venography rules out the need for anticoagulant treatment (Hull et al., 1981). The test has certain limitations and

Magnetic resonance venography (MRV) is an accurate noninvasive venographic technique for the detection of DVT. It has a sensitivity and specificity comparable to contrast venography (Carpenter et al., 1993). Furthermore, it can detect thrombi places not seen by the conventional venography, such as pelvic, ovarian veins or vena cava. Two major limitations for MRV are present, namely, the expensive cost and prolonged time necessary (Carpenter et al., 1993).

Scintigraphy has been described as a diagnostic tool for DVT (Knight, 1993). However, the

The diagnosis of PE may be made by a variety of imaging techniques, including chest X-ray, ventilation-perfusion scan, computed tomography (CT) of the chest vessels and pulmonary

On clinical suspicion of PE, the initial evaluation is made using chest X-ray, Electrocardiography (ECG) and ABG. Further evaluation is made by ventilation-perfusion

Currently, CT venography combined with pulmonary CT angiography for the detection of PE is increasingly used to confirm the diagnosis of suspected PE and the results have been

The incidence of DVT and subsequent PE can be decreased by adopting certain prophylactic mechanical and/ or pharmacologic measures, which have been proved to be safe and effective in most types of major surgeries (Martino et al., 2007; Geerts et al., 2008). Mechanical methods act by reducing stasis of venous blood and may stimulate endogenous fibrinolysis, while pharmacologic agents act by clot prevention through the various steps of

Mechanical prophylaxis is usually simple to conduct and relatively less costy. It may be achieved through the use of graduated compression stockings, anti-embolism stocking, electrical stimulation of the leg muscles, intermittent external pneumatic calf compression and/ or the use of specific tables (Martino et al., 2007; Geerts et al., 2008; Miller, 2011).

These measures are very effective in most surgeries and therefore, should be made a routine practice (Agnelli, 2004). Low-dose unfractionated heparin or low-molecular-weight heparin

data of its clinical efficacy compared to the standard methods are still lacking.

scan, CT of the chest vessels (Gulsun Akpinar & Goodman, 2008).

the clotting cascade (Martino et al., 2007; Geerts et al., 2008).

extremely promising (Krishan et al., 2011).

**5. Prophylaxis of DVT/PE** 

**5.1 Mechanical measures** 

**5.2 Pharmacologic measures** 

complications.

**4.3 Imaging in PE** 

angiography.

DVT may develop while the patient is on prophylaxis, therefore, the idea of dual prophylaxis (mechanical and pharmacologic) has emerged (Dainty et al., 2004; Whitworthet al., 2011).

This combination has been evaluated in patients undergoing colorectal operations. A combination of low-dose unfractionated heparin and graduated compression stockings has been found to be 4-fold more effective than low-dose unfractionated heparin alone in DVT/PE prophylaxis (Wille-Jorgensen et al., 2003). Similarly, this dual prophylaxis has been found to be cost-effective in high-risk patients undergoing surgeries for gynecologic tumors (Dainty et al., 2004).

### **5.4 Duration of prophylaxis during radical pelvic surgeries**

Following radical pelvic surgery, mechanical prophylaxis may be started before the operation, while pharmacologic prophylaxis is usually started after the operation and continued daily for 5–10 days or until the patient was fully mobile (Geerts et al., 2008; unpublished data by the author).
