Urology and Deep Vein Thrombosis

Deep vein thrombosis (DVT) and clots in the lung (pulmonary embolism (PE)) constitute major health problems that result in significant morbidity and mortality in the United States. It is estimated that venous thrombosis and pulmonary embolism are associated with 300,000 to 600,000 hospitalizations a year and that as many as 50,000 individuals die each year as a result of pulmonary embolism.

What is deep vein thrombosis?

In the leg, there are numerous veins whose function is to take the blood back to the heart. Sometimes, these veins get blocked by blood clots. When a blood clot forms in the deep veins of the leg, it is medically known as DVT. There are also superficial veins in the leg and clots can also form in them. However, it is the blood clots in the deep veins which are of a major concern.



What is the problem associated with DVT?

The major risk of blood clots is that they can break off and migrate to the lungs. In the lungs these clots can block your airways and prevent the blood from getting oxygen (pulmonary embolism). Blood clots in the lung can be life threatening. In addition, once a clot has occurred in the deep veins of the leg, the vein will be ruined and the valves inside will become deformed. This will result in life long swelling of the leg which may cause pain and swelling of the leg (post phlebitic syndrome).



How common are blood clots after urological surgery?

A lot of hospital data both from Europe and North America indicates that DVT occurs in at least 10-25% of surgical patients. Many of these clots are identified and treated, but some are missed and cause pulmonary embolism. Hospital data in North America indicate that clots in the lung occur in 1-3% of patients undergoing surgery. Further, the likelihood of a major pulmonary embolus leading to death is very high. Advancing age and malignancy are associated with even higher rates of both DVT and PE in urology patients.



What types of urological procedures are associated with a high risk of developing DVT?

DVT is a significant complication following any type of urologic surgery, but is most common after any open procedure. The following urological procedures are all associated with a risk for DVT.

Radical prostatectomy (removal of prostate has highest risk 2-3%)

Kidney transplant

Radical nephrectomy (removal of kidney)

Partial nephrectomy (only part removal of kidney)

Transurethral surgery (TURP) 0.3%

Laparoscopic nephrectomy (kidney removed using camera)

Bladder surgery

Advanced age and cancer contribute to thromboembolic risk for all urologic surgical patients.



What are risk factors for developing DVT?

There are many risk factors for developing blood clots and some of these include:

- Obesity

- An inherited tendency to form blood clots

- age (greater than 60)

- Previous blood clot

- Surgery- almost any type but especially hip, knee, abdominal

- taking the birth control pill

- Heart failure

- Cancer

- sitting in a plane for a long time

- Paralysis

How do I know if I have DVT?

A number of individuals will not even know if they have a blood clot in the leg. When the symptoms do occur, they may include:

- Leg swelling

- Leg pain

- Low grade fever

- A tender rope like feeling at the back of the calf

- Warm ankle

- Pain on walking

How do I know if I have PE?

In a few individuals the first sign of DVT can be the chest pain associated with a PE. The warning signs and symptoms of a pulmonary embolism include:

- Chest pain or discomfort. This pain or discomfort usually gets worse when you take a deep breath or when you cough.

- Sudden onset of shortness of breath. This is a very common symptom

- Fast heart and breathing rates

- Lightheaded or dizzy

- fainting spells

- coughing up blood

- heightened sense of anxiety (something is not right)

How is diagnosis of DVT made?

The above symptoms are not diagnostic for DVT and may resemble other medical disorders. To confirm the diagnosis, other radiological tests are required.

Blood test: The majority of individuals who develop a DVT or PE have an elevated blood level of a clot-dissolving substance called D dimer. However, D dimer levels are also increased in other medical conditions and the test is not very specific. At present, the test is used to identify individuals who are at risk for recurrence of DVT.

Duplex ultrasound: This non invasive painless test can rapidly identify if there is a clot in the leg. It can also determine the size and location of the clot. However, the test cannot determine if there is a blood clot above the groin area and pelvis.

MRI: MRI is never the first test of choice. If a blood clot is suspected in the pelvis or groin area, MRI is an excellent modality. It is painless and does not expose one to radiation. It is slightly more expensive than ultrasound.

Venogram: Venogram is a rarely performed test today. It requires the injection of a dye and radiation exposure. With the availability of ultrasound and MRI, venogram is only done when these 2 tests are non diagnostic.

What is the treatment of DVT?

The goal of treatment is to prevent the blood clot from growing, to ensure that it does not break off and travel through the veins to the lungs, and to help reduce the possibility of another blood clot forming.

Treatment may include:

Bed rest: When a new clot is discovered it is essential that one stay in bed for at least 4-7 days. This is done so that the clot does not break off while walking.

Medications: There are numerous blood thinning medications to treat DVT. In the hospital, you will be placed on a blood thinner (heparin) which is given via an IV. After a few days, you will be switched over to a pill (Warfarin) which you will have to take for at least 6-9 months.

What are complications of blood thinners?

The major complication is bleeding. Bruising is another common side effect of these medications. Thus, when taking these medications one should avoid any activity that can cause trauma.

What happens if I cam unable to take blood thinners?

In some cases, an umbrella like device (IVC Filter) can be placed in the large vein. This device will prevent the blood clots from going to the lungs. However, these devices are temporary solutions and also have their own complications. They are also expensive.

How does one prevent DVT?

The best treatment for DVT is to prevent it. There are various preventive measures. There is no single method that is the best so a combination approach is the most useful;

Activity: For those who are involved with a profession where they sit of stand for prolonged periods, one should move around every few hours.

Mobile: After surgery, one should try and be mobile as soon as possible. This mobility will prevent DVT. Even when recuperating at home, one should try and walk at least 2-3 times daily.

SCDs: For hospitalized patients, one should wear the pneumatic sequential compression devices (SCDs). These specially designed stockings squeeze the calf and thigh every few seconds and are helpful in preventing DVT. Today, they are also available for home use.

Stockings: One should wear compression stockings if you have any one of the above risk factors for developing a DVT.



Medications: For those individuals who are at high risk for developing DVT, there are medications one can take to prevent DVT. These medications (low molecular weight heparin) can be used at home or in the hospital.

Final Word

Most health care workers are well aware of DVT and its consequences. If you feel that you may be at risk for a DVT or would like to learn more, discuss this with your family physician, urologist or any other health care worker.