Venous ulceration is the most severe manifestation of chronic venous disease and will recur in 100% of noncompliant patients within 3 years. Interventions proven to be effective in reducing the incidence of recurrence include the use of compression stockings and removal of an incompetent superficial venous system. However, despite these interventions, ulcers may recur in as many of 12% of patients within 12 months. Efforts to prevent recurrent ulceration in these patients have led to a proliferation of interventions of unproven value such as ablation of incompetent perforators. The authors of this manuscript sought to identify the incidence of occult iliocaval venous obstruction as a cause of venous ulceration and its recurrence.
The authors used CT or MR venography to evaluate for the presence of occult iliocaval venous obstruction in 64 patients (78 limbs) with C5-6 disease. Using standard ultrasound criteria, reflux was present in the deep, superficial, or both systems in 13%, 38%, and 49% of limbs respectively. However, occult iliocaval venous obstruction of > 50% diameter reduction was identified in 37% of patients, including complete occlusion in 9% of patients and > 80% stenosis in another 14% of patients. Notably, abnormal ultrasound findings in the common femoral veins (diminished respiratory variation and flow augmentation with compression) had a sensitivity and specificity of 77% and 100% for identification of a > 80% stenosis by cross sectional imaging. Women were more likely to have iliocaval venous obstruction, as were those with a history of DVT (12.3 X increased risk) or deep venous reflux (17.7 X increased risk). Based upon their findings, the authors suggest that patients with abnormal common femoral waveforms on duplex ultrasound go directly to percutaneous venography and intervention, while those with a history of DVT or deep venous reflux should go further evaluation with CTV or MRV. Limbs with isolated superficial reflux likely require no further evaluation.
Although previous studies have documented a significant incidence of iliac vein compression in normal populations undergoing CT of the abdomen, this is the first study to evaluate the incidence of potentially clinically important
...those with a history of DVT or deep venous reflux should go further evaluation with CTV or MRV
iliac vein obstruction in patients with active or healed venous ulceration, all of whom are at high risk of recurrence. More than one-third of such patients will have > 50% obstruction and almost one-quarter > 80% obstruction of the iliocaval venous outflow. This study further demonstrates that although the specificity of ultrasound for the identification of iliocaval venous obstruction is high, its sensitivity is inadequate to exclude proximal venous obstruction in these patients. Finally, the study also identifies patients in whom further evaluation for iliocaval venous obstruction should be especially considered – women, patients with a history of DVT, and those with axial deep venous reflux. Unfortunately, as the authors acknowledge, despite identifying iliocaval venous obstruction as a potentially important problem in this patient population, the study does leave several questions unanswered. Important
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