Popliteal vein aneurysm is a local expansion of a venous vessel located under the knee joint. As a rule, it occurs against the background of varicose veins of the lower extremity. It is manifested by a feeling of discomfort, swelling of the leg. Possible neurological disorders due to compression of the fibular nerve. It can be asymptomatic, sometimes it is diagnosed only with the development of thromboembolic complications – venous thrombosis or pulmonary embolism. It is diagnosed on the basis of imaging studies: ultrasound, MRI, contrast CT or phlebography. Treatment is resection with the creation of an anastomosis or replacement of the site with an autovene.
Q87.8 Other specified vein lesions
Popliteal vein aneurysm is a rare pathology, less than 250 cases of the disease have been described in the specialized literature. Phlebologists believe that the actual prevalence of aneurysms of this localization is somewhat higher, since some cases are asymptomatic. The importance of the problem is due to the high probability of developing thrombosis and thromboembolism, including recurrent ones. Mostly middle-aged and older people get sick.
Causes of popliteal vein aneurysm
Unlike superficial venous aneurysms, which can be congenital in nature, popliteal vein aneurysm is formed during life. The following factors are considered the reasons for its formation:
- constant increase in venous pressure;
- increased blood flow rate;
- turbulent swirls of the blood flow in this part of the vessel.
Pathology develops against the background of varicose veins. There is no clear correlation between the severity of varicose veins and the probability of aneurysm formation.
An increase in pressure and an uneven distribution of load on the vascular wall leads to a change in its structure. Muscle and elastic fibers are destroyed or replaced by connective tissue. The tone of the vessel wall decreases. The lumen of the vein increases. A local expansion is formed, in which favorable conditions for the formation of blood clots are created.
Specialists in the field of phlebology distinguish two types of popliteal vein aneurysms:
- Baggy (sac-shaped, saccular). The vein wall protrudes from one side.
- Fusiform (fusiform). The vein cavity expands from all sides.
There are no clear criteria for determining local expansion as aneurysms in the literature. Some authors suggest that the increase in diameter by half is considered a pathology, others – three times compared to normal indicators.
Symptoms of popliteal vein aneurysm
Patients complain of a feeling of discomfort in the popliteal region and on the posterior surface of the lower leg. After a long stay on the legs, by the end of the day there is swelling of the distal parts of the limb. In some cases, an asymptomatic course is observed, the pathology is detected accidentally during examination for varicose veins or is detected after the development of thromboembolic complications.
On external examination, the popliteal region is not changed, the superficial veins in the basin of the large, small or both subcutaneous veins are dilated. Large aneurysms can reach 8 cm, with the occurrence of large protrusions in the popliteal fossa, a soft tumor-like formation is sometimes palpated.
In 2/3 of cases, blood clots are detected in the aneurysm cavity during ultrasound. The ingress of a blood clot into the pulmonary vein system is the cause of PE, which poses a danger to the patient’s life. In some patients, thrombosis of the deep veins of the lower extremities develops when a thrombus is detached, the outcome of which may be chronic venous insufficiency. With compression of the common peroneal nerve, sensory and motor disorders occur according to the type of neuropathy.
Diagnostics of popliteal vein aneurysm
Diagnostic measures are carried out by phlebologists. In the presence of complications, vascular surgeons and neurologists are involved in the examination of the patient. They carry out a survey, a general inspection. The following visualization techniques are used:
- Duplex scanning of veins. The main method of research. During the procedure, blood flow parameters are evaluated, the degree of expansion of the vein in the popliteal zone is determined, the type of aneurysm is determined, blood clots are detected in the vessel cavity, the condition of superficial and deep veins is studied.
- CT venography. It is produced using bolus contrast. Complements the data obtained during the ultrasound examination of the veins.
- MRI of the vessels of the extremities. Due to the high cost and lower availability, it is used infrequently. Allows you to estimate the width of the lumen and the thickness of the vessel wall, to clarify the size of the thrombus (if present) and the nature of blood flow.
- Phlebography. It is a traditional method for studying the condition of veins, it is used when ultrasound is not informative enough, CT or MRI is impossible.
Treatment of popliteal vein aneurysm
Due to the high risk of thrombosis and embolism, surgical treatment is required. In the absence of thromboembolic complications, planned interventions are performed in a hospital setting. Symptomatic aneurysms and asymptomatic dilations with a diameter of more than 2 cm are considered as indications. The following techniques are used:
- Tangential resection. It is indicated for small saccular aneurysms. The altered lateral part of the vessel is removed, the defect is closed with an autovenous patch.
- Resection with anastomosis. It is recommended for sac-like extensions of small size. The affected area of the vein is excised, an end-to-end anastomosis is created.
- Resection with autoprosthesis. It is used for large aneurysms. It provides for the removal of a portion of the vessel, followed by the replacement of the defect with an autograft from the patient’s subcutaneous vein.
- Excision with aneurysmography. It is produced with fusiform extensions. The aneurysm wall is excised longitudinally, the vein is strengthened by creating a duplication or suturing an autovenous patch.
The development of deep thrombosis is an indication for hospitalization, the appointment of heparin, and then anticoagulants. With severe circulatory disorders, thrombectomy is performed. Patients with PE are resuscitated, thrombolytic therapy is prescribed. In case of massive thromboembolism, thromboembolectomy or catheter fragmentation of the embolus is performed.
In the absence of complications, the prognosis is favorable. Relapses after surgical excision of an aneurysm are rare, the likelihood of thrombosis is determined by the severity of congestion in the lower extremities due to varicose veins. Early removal of the bulge during nerve compression allows you to fully restore sensitivity and movement. The outcome of the occurrence of PE and deep venous thrombosis depends on the severity of the complication.
Due to the rare occurrence of the disease, specific prevention has not been developed. It is recommended to follow general measures to prevent the occurrence and progression of varicose veins. In the presence of varicose veins, you should receive the prescribed treatment, regularly examine the veins to assess the condition of the vessels and exclude aneurysms.