**4. Diagnosis of DVT/PE**

176 Deep Vein Thrombosis

Endothelial injury of the vessel wall may be induced by surgical dissection in various radical pelvic surgeries (e.g. radical cystectomy) or from infiltration of the vessel wall by the tumor. In addition, catheters placed distally or proximally in the venous system are among the risk factors (Evans et al., 2010). However, in this situation, the risk of DVT/PE is determined by multiple factors including catheter size (Evans et al., 2010), degree of vein trauma during catheter insertion and dwell and hypercoagulability of the patient' blood.

Hypercoagulability or thrombophilia or prothrombotic state is a blood coagulation disorder with a subsequent increase in the incidence of thrombosis (Heit, 2007). There are multiple genetic and acquired risk factors that influence thrombophilia. The presence of these inherited risk factors alone usually does not cause thrombosis unless an additional risk

Antithrombin deficiency, which is the first major form of thrombophilia, was identified in 1965, while the most common defects, such as factor V Leiden mutation and prothrombin gene mutation G20210A were described in the 1990s (Dahlbäck, 2008; Rosendaal & Reitsma, 2009). The risk of developing DVT/PE increases significantly if one of these abnormalities is

There are various possibilities, which can induce a hypercoagulable state during major radical pelvic surgeries. These possibilities include decreased fibrinolytic activity associated with surgery (Egan et al., 1974), increased level of coagulation factors I, V, VIII, IX, X, and XI, the presence of activated intermediate coagulation products such as thrombinantithrombin III complexes and abnormalities of the platelets (Piccioli et al., 1996). In addition, the malignant cells may secrete a substance promoting coagulation, such as tissue factor and cancer procoagulant or factors that influence vascular endothelial permeability such as vascular endothelial growth factor and subsequently stimulate fibrin deposition

In the prospective study of Duke University Medical Center 411 patients undergoing major abdominal and pelvic gynecologic surgery were evaluated for DVT and the related possible risk factors (Clarke-Pearson et al., 1987). In this study, the important factors, which maintained statistical significance in stepwise logistic regression model were age, edema of the ankle, type of surgery, nonwhite race, presence of varicose veins, history of radiation

It has been found that the risk factors for distal DVT are different from those of proximal DVT. In the national (France) multicenter prospective OPTIMEV study, out of 6141 patients with symptoms suggestive of DVT, diagnosis was objectively confirmed in only 1643 and isolated distal DVT was more common than proximal one (Galanaud et al., 2009). In this study, acute or transient risk factors, such as recent surgery, recent plaster immobilization and recent travel, were more frequently discovered in distal DVT. On the other hand, in proximal DVT chronic risk factors such as active cancer, congestive heart failure or

Active cancer and related chemotherapy can increase the incidence of DVT by multiple mechanisms. In chronic lymphocytic leukemia patients, studies showed a link between lenalidomide associated DVTs and inflammation, upregulation of TNFα and endothelial cell

factor is present (Heit, 2007; Kyrle et al., 2010).

(Goad & Gralnick, 1996).

dysfunction (Aue etal., 2011).

present in patients undergoing radical pelvic surgery.

preoperatively, past DVT and duration of surgery.

respiratory insufficiency and age above 75 years were more frequent.

The majority of cases of DVT/PE have one or more risk factor. Many cases of DVT/PE are asymptomatic. Suspected pulmonary embolism is a medical emergency and can be fatal. In symptomatic DVT cases, the patient may present with lower limb pain, unilateral leg swelling, redness and sometimes prominent superficial veins. A tender calf, especially with dorsiflexion (Homan's sign) and rarely a palpable venous cord are among the possible physical signs. However, the presence of these manifestations is nonspecific, because in more than 50% of the cases presenting with these symptoms, DVT is absent (Dainty et al., 2004). Therefore, diagnosis of DVT based on symptoms only is problematic and proper hospital assessment and further diagnostic tools are needed for accurate diagnosis. Similarly, most of the symptoms and signs of PE are nonspecific and simulate post-surgery pulmonary complications. However, physicians should maintain a high degree of suspicion if the patient is complaining of pleuritic chest pain, hemoptysis, dyspnea, tachycardia and tachypnea.

#### **4.1 Laboratory testing**

The use of a simple prediction tool, together with the laboratory tests of D-dimers and arterial blood gases (ABG) in cases of suspected PE are useful tools to exclude or prove DVT (Crisan et al., 2011). D-dimers are fibrinogen degradation products which are generally present at higher concentrations than normal in the blood of people with DVT.

#### **4.2 Imaging in DVT**

Imaging for DVT includes B-mode duplex Doppler ultrasound, impedance plethysmography, contrast venography, and magnetic resonance venography (MRV). Doppler ultrasound is currently the most common technique for the diagnosis of symptomatic DVT. B-mode ultrasonography allows a bi-dimensional image of the vessels of the lower extremity and when compression techniques are used, a sensitivity of up to 90% and a specificity of 96% to 100% can be achieved in the detection of DVT (Cronan et al., 1987; O'Leary et al., 1988).

In duplex ultrasonography B-mode is combined with Doppler flow, therefore, providing information about flow velocity. When color Doppler flow is used with compression Bmode ultrasonography (color duplex ultrasonography), additional data on the direction of flow is gained (Cronan et al., 1987; O'Leary et al., 1988).

Impedance plethysmography is a noninvasive diagnostic test that has a good accuracy in the detection of proximal DVT, when the results are analyzed in combination with positive clinical data (Kearon et al., 1998). However, false positive results may be obtained with this test and if the results of this test are non-diagnostic or not coping with the clinical data, venography should be performed (Kearon et al., 1998).

Contrast venography is still the gold standard for the diagnosis of DVT and is used by investigators as a reference standard for testing the new noninvasive diagnostic DVT measures (Tapson et al., 1999).

The technique is done as classically described (Rabinov & Paulin, 1972). A misdiagnosis is expected if all the deep veins from the leg up to the vena cava are not seen. When there is a persistent filling defect in the lumen of 2 or more veins, the diagnosis of DVT is confirmed

Deep Venous Thrombosis After Radical Pelvic Surgery 179

(LMWH) are the drugs of choice in patients undergoing radical pelvic operations in the fileds of general, vascular, major urologic and gynecologic surgeries (Agnelli, 2004). In urologic patients judged as low-risk, early postoperative mobilization is the only measure needed. On the other hand, higher-risk patients should receive vitamin K antagonists,

Some investigators recommended a double prophylaxis of mechanical measures as well as pharmacologic measures using pre- and post-operative anticoagulation, usually in the form of LMWH (Whitworthet al., 2011). They found that the use of preoperative anticoagulation seems to significantly decrease the risk of DVT in high-risk patients undergoing major gynecologic surgeries. In addition, there was no significant change in the rates of

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

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

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;

The goals of treatment of patients with DVT and PE are to prevent local growth of the thrombus, prevent the thrombus from breaking down into small pieces (emboli) and traveling to other places, prevent complications of DVT, prevent recurrence of the thrombus

DVT is treated by immediate institution of anticoagulant therapy. Treatment is given as either unfractionated heparin or low molecular weight heparins, followed by few weeks to 6 months of oral anticoagulant therapy (Clarke-Pearson & Abaid, 2008). However, life-long anticoagulation has been recommended in some patients with active cancers after partial improvement or failure of treatment, because they remain at very high risk to recurrent DVT (Clarke-Pearson & Abaid, 2008).Low concentrations of heparin can inhibit the early stages of blood coagulation. However, higher concentrations are needed to inhibit the much higher concentrations of thrombin that are formed if the DVT process is not modulated (Hirsh &

and in some clinical situations accelerate fibrinolysis (Hirsh & Hoak, 1996).

LMWH and/ or fondaparinux (Agnelli, 2004).

complications secondary to this protocol.

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

**5.3 Dual prophylaxis** 

(Dainty et al., 2004).

unpublished data by the author).

**6. Treatment of DVT/PE** 

Hoak, 1996).

al., 2011).

(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 complications.

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