In a study comparing multiplanar venography to intravascular ultrasound (IVUS) for diagnosing common or external iliac and common femoral vein stenosis, IVUS imaging was found to change both the treatment plan in 60/100 patients and the number of stents placed in 50/100 patients. Presenter Paul Gagne (Darien, USA) maintained that “without IVUS, iliofemoral vein occlusive disease would have been undertreated in the majority of patients studied”.
The VIDIO (Venography versus intravascular ultrasound for diagnosing iliofemoral vein occlusive disease) study is a prospective, single-arm, multicentre, study designed to compare multiplanar venography to intravascular ultrasound for diagnosing common or external iliac and common femoral vein stenosis, and the extent, and morphology (ie. stenosis versus scar, compression or post-thrombotic scar) of the occlusive disease (primary endpoints). The patients enrolled have CEAP 4–6 (clinical) disease.
Secondary endpoints include clinical (CEAP and VCSS (Venous Clinical Severity Score)) and Quality of Life (QoL) (CIVIQ-14 and SF-36v2 questionnaires) improvement after intervention. Venous ulcers were monitored and measured in CEAP 6 patients. Patients were evaluated for chronic venous obstructive disease due either to compression or scar from prior deep vein thrombosis (ie. chronic deep vein thrombosis or deep vein thrombosis).
The study was conducted at 14 sites in the USA, Poland, UK and Italy. Enrolment was initiated in July 2014 and completed in July 2015. Clinical follow-up was completed at the end of December 2015.
According to Gagne, 100 patients underwent standardised, multiplanar venography (antero-posterior, 30 degree RAO and 30 degree LAO) of the common or external iliac vein and common femoral vein of the index limb (Lesser Femoral Trochanter to Inferior Vena Cava) to identify stenosis or obstruction. Based on these images, the investigator determined if there was a flow-limiting lesion requiring intervention with a percutaneous transluminal angioplasty and/or stent. If yes, the type of intervention, balloon and stent to be used was to be stated. The patient then underwent IVUS interrogation of the same common or external iliac vein and common femoral vein segments. Following IVUS, the investigator was asked again, if there was a flow-limiting lesion requiring intervention with a percutaneous transluminal angioplasty and/or stent. If yes, the type of intervention, balloon and stent to be used was to be stated. Differences in identified intravenous pathology and intervention were then compared for the two imaging modalities.
Intervention was at the discretion of the investigator and was not defined by the protocol. Baseline, one and six-month follow-up included venous duplex ultrasound, and the clinical and quality of life assessment tools.
The goal of the study, Gagne said, “was to determine if significant additional diagnostic information was gained when the central deep veins of the lower extremities of patients with CEAP 4–6 disease were evaluated with both IVUS and multiplanar venography versus venography alone. The intent was to determine if clinically significant venous disease was missed when venography alone is used to evaluate these patients. We also analysed whether IVUS altered the procedure performed compared to the plan following venography”.
Gagne reported, “In the 300 vein segments studied, IVUS detected lesions in 63 (21%) segments that were missed by venography. Venography detected only five lesions not detected by IVUS. Thus, IVUS was significantly more sensitive for identifying iliofemoral vein occlusive disease than venography. We also found that the degree of stenosis was 11% greater with IVUS than venography based on diameter measurements and that venography missed almost 18% of lesions based on cross sectional area measurements and calculations assessed by the core laboratory ‘over read’ of the imaging.”
In the study, IVUS imaging changed both the treatment plan in 60/100 patients and the number of stents placed in 50/100 patients. Without IVUS, Gagne maintains, “iliofemoral vein occlusive disease would have been undertreated in the majority of patients studied”.
Using the SF-36v2 QoL tool, patients treated with stents had almost uniform improvement of all measures which was statistically significant at one and six months. Patients who did not receive stenting had no significant change in their QoL. “Patients with treatable iliofemoral vein occlusive disease respond very well to stenting, such that making the diagnosis of chronic venous outflow disease important for improving the lives of these chronic venous disease patients,” Gagne said.
In conclusion, Gagne reported, the VIDIO study has shown that “IVUS appears to be more sensitive for identifying significant iliac and common femoral vein outflow obstruction and is more accurate for measuring the degree of stenosis based on both cross sectional area measurements and diameter stenosis and appears to be the best guide for stent intervention.”
“Finally, I believe that IVUS should be considered the gold standard for diagnosing and directing treatment in the iliac and common femoral veins and the basis for trial research imaging in the future,” he maintained.