Teaching Case

A 64-year-old female patient suffers from a progressive dyspnea for 2 months. The patient indicates pleuritic pain in the the left hemithorax with a 8/10 intensity. She also notes a 24 hour-long oedema and pain in the left lateral neck region and the ipsilateral supraclavicular region. She denies other symptoms.

A CT-bodyscan is requested on the suspicion of a lymphoma presence.

Saccular dilatation of the proximal third of the left subclavian vein measuring 14.8x16x14.6 mm is documented [Fig. 1a, b and c] with an aneurysm/vein ratio of 16/9.5 mm = 1.68. Angiography confirms an aneurysm in the subclavian vein [Fig. 2a and b]. Doppler exploration confirms an aneurysm on the cephalad side of the vein, and in its interior partial thrombosis can be seen [Fig. 3a, b and c].

Endovascular therapy with coils is indicated due to the presence of oedema and pain in the lower left neck. After signing the informed consent, (explaining possible complications such as vein thrombosis or rupture and coil migration) the procedure is performed without complications, excluding the aneurysm from the systemic vascularisation, evidenced in phlebography [Fig. 4]. Two detachable coils were used, (5x150mm, and 6x200mm). Doppler insonation shows an acoustic shadow artefact (coils) and permeability [Fig. 5a and b].

Venous aneurysms typically consist of real aneurysms, mostly saccular, appearing as isolated soft tissue masses or as a component of arteriovenous malformations, reaching a size two to three times greater than the calibre of the main vessel and its aetiology is generally unknown, although focal defects in the development of the tunica media are suggested as a possible explanation [1, 2, 3]. They're more common in the jugular veins, central thoracic veins and visceral veins, affecting any age and gender [3, 4]. When they occur in the head and neck, they often manifest as asymptomatic masses that increase in size with Valsalva manoeuvres [1, 2, 3, 5].

There are 3 types of venous aneurysms: congenital (neurofibromatosis or Menkes disease), traumatic and acquired (for example arterialised vein grafts.) [5].

Possible complications include: thromboembolism, rupture, venous obstruction and compression of adjacent structures [1, 6, 7]. When these entities occur in the legs or abdomen, surgical resection is recommended due to higher risk for these complications. There are reports of up to a 71% incidence of deep vein thrombosis and pulmonary embolism in popliteal or femoral vein aneurysms, and 41% in intra-abdominal veins [1]. The treatment indications of a venous aneurysm that does not correspond to these anatomical areas are: complications, sustained growth and cosmetic alteration [2].

In our review of the literature there's report of 5 cases of subclavian vein aneurysms and only one of these cases presented a pulmonary thromboembolism as a complication [1, 3, 8].

Doppler Duplex ultrasonography and computed tomography with intravenous injection of non-ionic water-soluble iodinated contrast are the best way to evaluate this disease. Alternatively MRI angiography or phlebography can be performed [2, 3, 9]. Nevertheless, given the benign nature of these diseases when they occur in the mediastinum or neck, very invasive procedures are not recommended unless the patient presents any of the mentioned indications [2].

Venous aneurysms have been treated with conservative management and monitoring, open surgery and also endovascular techniques, which are favoured since they are minimally invasive. Among the latter, the use of coils, glue, stents or thrombin can be included. Regarding the use of stents, embolisation of the aneurysm can be carried out with the stent in place or aneurysm exclusion can be performed by placement of a stent-graft. The stent with the ends positioned at least 15 mm on either side of the aneurysm, serves as a scaffold for intra-aneurysmatic coils implantation, preventing herniation to more proximal vessels allowing denser packing [8].