Thrombolysis and stenting for DVT in a patient with May-Thurner syndrome

Clinical History

A 26-year-old male patient presented with acute onset of left leg pain and swelling. He also complained of intermittent vomiting and lower abdominal pain. The white cell count was normal with slightly raised C-reactive protein. The D-Dimer blood levels were markedly elevated.

Imaging Findings

The Doppler ultrasound showed extensive acute thrombus in the left leg veins (Fig. 1). CT performed for lower abdominal pain once again showed the thrombus to the level of the left common iliac vein which appeared compressed by the right common iliac artery (Fig. 2). The venogram confirmed extensive DVT with typical tram tracking and filling defects (Fig. 3). Thrombolysis was commenced using Alteplase (TPA) and follow-up venogram after 24 hours revealed near-complete resolution of the thrombus (Fig. 4). The patient was then discharged on warfarin. Five months later, the patient was re-admitted electively and a 12 x 60 mm self-expandable wall stent was inserted. A completion venogram demonstrated good contrast flow into the IVC (Fig. 5). The patient was asymptomatic at his last follow up 6 months post-stent insertion with a normal Doppler ultrasound (Fig. 6).

Discussion

May-Thurner syndrome is a condition in which patients develop iliofemoral deep venous thrombosis (DVT) due to an anatomical variant in which the right common iliac artery overlies and compresses the left common iliac vein against the lumbar spine. The reported incidence of the variant is 20%; however, it is rarely considered in the differential diagnosis of DVT, particularly in patients with other risk factors. [1, 2]. It is three times more common in women than in men.
Typical presentation is in the second to fourth decades of life with left iliofemoral DVT with or without other risk factors of DVT. The diagnosis is usually achieved by venography and CT findings of the compressed and effaced left common iliac vein as seen in our patient. It has been reported that systemic anticoagulation alone is insufficient treatment, and a more aggressive approach is necessary to prevent recurrent DVT [2]. Many institutions advocate “hybrid approach” in the treatment which consists of combination of catheter-directed thrombolysis and endovascular stenting [3]. Anticoagulation is usually recommended for 6 to 12 months duration. It is recommended to use a large self-expandable stent extending into the IVC to prevent migration. Stent placement has proven to be highly successful in May-Thurner Syndrome with reported 2 year iliac vein patency rates of 95% to 100% [4].

In this patient, access was obtained through a thrombosed gastrocnemius vein. A catheter was passed through the thrombus and a bolus of 10 mg of TPA was seeded throughout its length. An infusion catheter was then placed with its functioning segment in the left iliac system. Split level infusions were set up delivering 0.5 mg of TPA through the sheath and infusion catheter respectively giving a total dose of 1 mg per hour. This was continued for 25 hours until the review venogram showed near-complete resolution of the clot. Anticoagulation was commenced and he was discharged on warfarin. After MDT decision, he was readmitted electively for left common iliac vein stent which was successfully performed. The patient is currently doing well with patent leg and iliac veins and the stent as shown at the last follow-up ultrasound.

In summary, this is an under-recognized condition and needs to be particularly considered in relatively young patients presenting with extensive DVT. More aggressive treatment options such as thrombolysis and stenting should be considered along with anticoagulation to prevent long term morbidity.

Differential Diagnosis List

Final Diagnosis

Thrombolysis and stenting for DVT in a patient with May-Thurner syndrome

URL:	https://eurorad.org/case/11486
DOI:	10.1594/EURORAD/CASE.11486
ISSN:	1563-4086