Blood-Vessel Anomaly Boosts DVT Risk after ACL Reconstruction

The overall rate of symptomatic lower-extremity deep vein thrombosis (DVT) following arthroscopic ACL procedures is reported to be <0.3%, and guidelines from the American College of Chest Physicians recommend against DVT prophylaxis prior to arthroscopic knee surgery, unless a patient has risk factors for blood clots. But some patients are unknowingly at high risk for clots, as a case report by Ackerman et al. in the June 10, 2105 JBJS Case Connector shows.

A 45-year-old woman presented for arthroscopic ACL reconstruction in her left knee. Unbeknownst to her or her surgeons, the patient had asymptomatic May-Thurner syndrome—an anatomic variant of the iliac blood vessels in which the right common iliac artery crosses over the left common iliac vein, compressing the vein against the lumbar spine.

Nine days after ACL surgery, the patient showed up in the ED with pain and swelling in the operative leg. Ultrasound revealed an extensive DVT extending distally from the common femoral vein. Imaging of the chest and cardiac workups were negative for heart or lung thromboembolism.

A heparin drip was started, and a vascular surgeon ordered a left-leg venograph, which revealed a large clot extending from the origin of the left common iliac vein to the insertion site of the catheter in the popliteal vein. Severe stenosis of the left common iliac vein confirmed May-Thurner syndrome (see image below).

CC_N00202_gs_f1

Treatment consisted of an infusion of tissue plasminogen activator (Alteplase) directly to the clot, continued intravenous heparin, and an angioplasty with stents to open the stenosed left common iliac vein. Mechanical thrombolysis and aspiration of a residual femoral vein thrombus was accomplished with a Trellis device.

Postoperatively the patient was transitioned to therapeutic warfarin for six months and instructed to wear compression stockings. She completed her ACL physical therapy protocol uneventfully, and one year after the ACL reconstruction, the knee graft was stable and there was no evidence of post-thrombotic syndrome.

The authors remind orthopaedists that May-Thurner syndrome, which is more common in women than men, should be suspected in the presence of an extensive iliofemoral DVT. They emphasize that multimodal and aggressive treatment, in consultation with a vascular specialist, should be initiated to bust the clot and reduce the risk of post-thrombotic syndrome. Post-clot, such patients should be maintained on warfarin for a minimum of six months, and patients with stents often require lifelong aspirin therapy.

Tags: , , , , , , , , , , , , ,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: