A comparison between intravascular ultrasound and venography in identifying key parameters essential for iliac vein stenting.

OBJECTIVE: Deep venous stenting has become the primary treatment option for obstructive venous disease. Precise identification and quantification of the disease as well as localization of optimal landing zones are key elements to success. Compared with venography (anteroposterior projection), intravascular ultrasound (IVUS) seems to be more sensitive in determining those parameters. This study was a blinded comparison of the relative accuracy of venography compared with IVUS in determining key parameters essential for iliac vein stenting. METHODS: Between October 2013 and November 2015, there were 155 limbs (152 patients) that underwent an endovascular intervention for chronic iliofemoral vein stenosis. Venography and IVUS data were reviewed by vascular surgeons and radiologists, respectively, each blinded to the other to identify location and severity of maximal stenosis, location of iliac-caval confluence, and optimal distal landing zone. Data from venography were compared with data from IVUS. Maximal stenosis was defined as the most severe stenosis found among the four segments-common iliac vein, external iliac vein, common femoral vein, and infrarenal vena cava. IVUS was the "gold standard" for comparisons. RESULTS: Venography failed to identify lesion existence in 19% of limbs. The median maximal area stenosis was significantly higher with IVUS than with venography (69% vs 52%; P < .0001). Furthermore, venographic correlation with IVUS for the anatomic location of maximal stenosis was present in only 32% of the limbs; venography missed the location of maximal stenosis in more than two-thirds of limbs. The iliac-caval confluence location on venography correlated with IVUS findings in only 15% of patients. In 74%, it was located higher with IVUS than with venography. The mean difference was one vertebral body. Agreement between venography and IVUS on location of the distal landing zone was only 26%. The distal landing zone defined with IVUS was lower than with venography in 64% of limbs. CONCLUSIONS: Compared with IVUS, venography substantially and significantly misses stenotic lesions-their location and severity; venography also misidentifies the location of the iliac-caval confluence and the distal landing zone in the majority of limbs. Those differences between IVUS and venography suggest that IVUS is the better diagnostic and procedural tool in iliac-caval stenting.

Peripheral venous hypertension in chronic venous disease.

BACKGROUND: Microvascular venous hypertension has emerged as a central feature of chronic venous disease (CVD). Yet, the incidence and severity of peripheral venous hypertension in the clinical setting have not been reported. This is an observational study of venous hypertension in the lower limb of a large cohort of patients with suspected CVD referred to a single referral center during a 16-year period. METHODS: Clinical and venous laboratory test data for 8868 limbs of 5792 patients with CVD symptoms seen from 1999 to 2015 were analyzed. Subset A limbs had a mix of obstruction/reflux or neither (n = 4132). These are limbs in which duplex ultrasound reflux (yes/no) status is known. The incidence and severity of obstruction in these limbs are unknown as tests of obstruction were not routinely performed. Subset B limbs had central obstruction (n = 159). These are limbs with intravascular ultrasound-proven stenosis in the iliac veins that was corrected by stent placement. Reflux was assessed by duplex ultrasound and air plethysmography (venous filling index [VFI90]). Pressure measurements included supine venous pressure, erect venous pressure, and ambulatory venous pressure (AMVP). Pressure measurements are categorized according to Clinical, Etiology, Anatomy, and Pathophysiology (CEAP) clinical class, reflux and obstruction with Venn distributions of prevalence. RESULTS: All pressures (supine, erect, and ambulatory) trended worse in higher CEAP clinical classes. Supine foot venous pressures were elevated in 70% and 76% of subsets A and B, respectively. A positive association between elevated supine pressures and reflux could not be shown in this study. Supine foot venous pressure did not worsen with increasing reflux in the two subsets, but erect foot venous pressure did. Elevated supine pressures were associated with obstruction in subset B. AMVP worsened in most higher reflux categories. Ambulatory venous hypertension was dominantly associated (Venn distribution) with reflux, less commonly with obstruction. CONCLUSIONS: Supine venous hypertension is associated with obstruction and does not worsen with reflux. In contrast, erect foot venous pressure worsens in severe reflux categories. Ambulatory venous hypertension worsens in higher CEAP clinical classes. It worsens with increasing reflux. AMVP is dominantly associated (Venn distribution) with reflux, not obstruction.