**2. Of venous thromboembolism**

Venous trombosis is usually located in the veins of the lower extremity. The thrombosis probably has its origin in the valve pockets of the veins of the lower leg. There are several pathogenetic factors, but a common denominator is reduction of flow velocity in the veins. This may occur in a varity of situations, e.g.:


These are classic examples of patients that may suffer a deep venous trombosis (DVT) or more severely a pumonary embolism (PE).

There are many clinical examples of variatons on the theme.

The thrombosis may begin in the popliteal or femoral vein progressing centrally until it breaks off and sends its potentially fatal embolism to the lungs. It may also have its origin in the iliac veins, in which case the diameter of the ensuing embolism is sufficient large to close off the entire pulmonary artery, causing immediate death.

Venous Thromboembolism as a Preventable Patient Injury:

**4. Venous tromboembolism and patient injury** 


**5. VTE and the database of the DPIA** 

VTE may be judged to be a patient injury in the following situations:

situation, where an experienced specialist would have done so,

of going to court (2).

been avoided,

the incident,

endure.

approved.

serious.

are met.

the DPIA.

benefits, and finally,

conditions:

Experience of the Danish Patient Insurance Association (1996 - 2010) 161

Association (DPIA) will consider these claims. The DPIA operates on a no-blame, no-fault basis and does not take any legal action beyond assessing damages. As a result, patients may file a claim with the DPIA free of charge with the sole purpose of seeking financial compensation. Thus, the injured patient is spared the expense of legal fees and the trouble

In general, financial compensation may be granted under any one of the following

1. an experienced specialist would have acted differently, whereby the injury would have

2. defects in or failure of the technical equipment were of major concern with respect to

3. the injury could have been avoided by using alternative treatments, techniques or methods if these were considered to be equally safe and potentially offer the same

4. the injury is rare, serious, and more extensive than the patient should be expected to

Compensation is calculated based on the extent of pain and suffering, reduced income, reduced ability to work, and medical expenses as well as whether the injury could be expected to be permanent. Compensation is rendered if the calculated amount exceeds 1,500 €. The government pays the compensations. After the decision has been made, the patient may file an appeal to the Patient Damage Appeal Board and further through the courts of law. From 1996 to 2010, the DPIA received 64.400 claims; 34.9 % of these were


In such cases the DPIA may consider to give compensation if the other conditions of the law

Since 1996 we have maintained a database of all claims. Until the end of 2010, there were 688 claims, where the complication was VTE. In table 1 is shown the number of patients with DVT alone, the patients who also had PE, and the patients with rare thombosis. The rates of approval of the claims are around 60 % compared to the average rate of 35 % of



A special variety of the disease exists, where an obstruction is present at the iliac venous junction. This is called the *left iliac vein syndrome*, and it is normally not associated with pulmonary embolism, as the lumen of the left common vena iliaca is partially obstructed by a fine net of the endothelium at the junction. The compression from the crossing of the right common iliac artery adds to the obstruction.

In some cases the source of embolism is located in a venous malformation, and the thrombi to the lungs may be small and not easily clinically detectable. The pressure in the pulmonary artery increases slowly over months with the continuing pulmonal embolization causing cronical *cor pulmonale*. The *foramen ovale* may open under the increased pressure in the right side of the heart, releasing minor emboli to the arterial circulation. The end result is usually cardiac arrest due to the increased pressure with dilation of the right ventricle.

In rare cases the thrombosis occurs in the veins of the upper extremity. The size of emboli from the arms is not sufficient to give any serious problem from the lungs, but it is important to know that this possibility exists.

Thombosis in the mesenteric veins is a very rare, but potentially deadly disease. The onset of symptoms is much slower than that of arterial vascular iscaemia, where as a rule you have only 6 hours from the embolization to completion of thrombectomy, if gangrene and resection should be prevented. In venous ishaemia there are often days or weeks of symptoms before the onset of gangrene, and if the ischaemia has progressed to gangrene, a simple resection will often be sufficient. Venous intestinal ischaemia is usually not recognized until laparotomy, and it may be very difficult to make the diagnosis by laparoscopy alone.

Thrombosis in the venous sinuses of the brain is an important side effect to birth control drugs, and must always be considered as a differential diagnosis when a patient on the pill develops symptoms from the brain.

Finally, another inborn vascular anomaly has bearing on the embolisation from the veins of the lower limbs: The *foramen ovale*, which normally closes at the time of birth, will sometimes remain open and allow emboli from the right side to cross over to the left side and continue in the arterial system. This is known as "paradox" embolisation, and is important to consider, when a patient at risk for venous thrombosis suffers an arterial embolus. The frequency of patent *foramen ovale* in autopsy studies is about 20 %, so this a significant risk, as the frequency of deep venous thrombosis is equally high (1).

The disease known as thrombophlebitis, where a subcutaneous vein is inflamed and thrombosed, has nothing in common with DVT. In the major part of the 20th century it was thought that thrombosis might spread from the superficial veins to the femoral venous system through the sapheno-femoral junction, wherefore acute ligature of the junction was advised. This indication for the sapheno-femoral ligature has since been abandoned. Also, the practice of anticoagulation with thrombophlebitis is no longer advised.
