Comparison of computed tomography venography and intravascular ultrasound in screening and classification of iliac vein obstruction in patients with chronic venous disease.

OBJECTIVE: To investigate power of computed tomography venography (CTV) to identify and characterize iliac vein obstruction (IVO) compared with intravascular ultrasound (IVUS) examination in highly symptomatic patients with chronic venous disease (CVD). METHODS: CVD CEAP C3-6 limbs with visual analog scale for pain score of greater than 3 and/or Venous Clinical Severity Scale of greater than 8 were prospectively investigated with CTV and IVUS examination. The segment of maximum IVO was verified and categorically classified: group I, 0% to 49%; group II, 50% to 79%; and group III, 80% or greater. The CTV's screening power to detect the point and degree of maximum IVO was compared with IVUS. RESULTS: The CTV point of maximum IVO was 80% in the left limb, 10% in the right limb, 10% bilaterally; 2% in the inferior vena cava; 91% in the common iliac vein (CIV) confluence (41.6% below the CIV confluence, 34.5 at the CIV confluence, and 23.9% above the CIV confluence); 7% at the external iliac vein (kappa index 0.841; P < .001, when compared with IVUS). The distal venous segment considered free of obstruction was above inguinal ligament: 68% (CIV, 47%; external iliac vein, 21%) 32% below the inguinal ligament (common femoral vein, 26%; deep femoral vein, 6%) (kappa index 0.671; P = .023, when compared with IVUS). The power of CTV to detect an IVO of 50% or greater (groups II and III) when compared with IVUS achieved a sensitivity and specificity ratio of 94.0% and 79.2%, respectively. The positive predictive value was 94%, the negative predictive value was 79.1%, accuracy was 86.7% (kappa, 0.733), and interobserver agreement was 92.1% (95% confidence interval, 87.1-97.7; kappa, 0.899). CONCLUSIONS: CTV is a powerful screening method in determining the precise point of compression and classifying IVO in limbs with symptomatic CVD when compared with IVUS. The prevalence of an obstruction above the iliac vein confluence is significant and should be considered in iliac vein stenting treatment strategy. The tomographic classification system proposed here may help to define the optimum technique of treatment, prognosis, and comparison of outcome results.

Comparison of computed tomography venography and intravascular ultrasound in screening and classification of iliac vein obstruction in patients with chronic venous disease

Objective: To investigate power of computed tomography venography (CTV) to identify and characterize iliac vein obstruction (IVO) compared with intravascular ultrasound (IVUS) examination in highly symptomatic patients with chronic venous disease (CVD). Methods: CVD CEAP C3-6 limbs with visual analog scale for pain score of greater than 3 and/or Venous Clinical Severity Scale of greater than 8 were prospectively investigated with CTV and IVUS examination. The segment of maximum IVO was verified and categorically classified: group I, 0% to 49%; group II, 50% to 79%; and group III, 80% or greater. The CTV's screening power to detect the point and degree of maximum IVO was compared with IVUS. Results: The CTV point of maximum IVO was 80% in the left limb, 10% in the right limb, 10% bilaterally; 2% in the inferior vena cava; 91% in the common iliac vein (CIV) confluence (41.6% below the CIV confluence, 34.5 at the CIV confluence, and 23.9% above the CIV confluence); 7% at the external iliac vein (kappa index 0.841; P < .001, when compared with IVUS). The distal venous segment considered free of obstruction was above inguinal ligament: 68% (CIV, 47%; external iliac vein, 21%) 32% below the inguinal ligament (common femoral vein, 26%; deep femoral vein, 6%) (kappa index 0.671; P » .023, when compared with IVUS). The power of CTV to detect an IVO of 50% or greater (groups II and III) when compared with IVUS achieved a sensitivity and specificity ratio of 94.0% and 79.2%, respectively. The positive predictive value was 94%, the negative predictive value was 79.1%, accuracy was 86.7% (kappa, 0.733), and interobserver agreement was 92.1% (95% confidence interval, 87.1-97.7; kappa, 0.899). Conclusions: CTV is a powerful screening method in determining the precise point of compression and classifying IVO in limbs with symptomatic CVD when compared with IVUS. The prevalence of an obstruction above the iliac vein confluence is significant and should be considered in iliac vein stenting treatment strategy. The tomographic classification system proposed here may help to define the optimum technique of treatment, prognosis, and comparison of outcome results. (J Vasc Surg: Venous and Lym Dis 2019;-:1-10.) Keywords: Iliac vein obstruction; Computed tomography Venography; Intravascular ultrasound; May-Thuner syndrome; Cockett syndrome; Classification

Correlation between venous pressure gradients and intravascular ultrasound in the diagnosis of iliac vein compression syndrome

Objective: The objective of this study was to evaluate the correlation between venous pressure gradients (VPGs) and intravascular ultrasound (IVUS) for the diagnosis of caval-iliac venous obstructions in patients with advanced chronic venous insufficiency. Methods: Fifty patients with advanced chronic venous insufficiency symptoms (Clinical, Etiology, Anatomy, and Pathophysiology class 3 to 6) were prospectively submitted to multiplanar venography (MV) with intravenous pressure measurements and IVUS. The patients' lower limbs were divided accordingly: group I, limbs with <50% obstruction on IVUS (n » 49); and group II, limbs with $50% obstruction on IVUS (n » 51). Receiver operating characteristic curves compared the diagnostic performance of the VPGs. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy assessed the performance of VPGs in categories to determine the presence of significant obstruction. Logistic regression assessed the capacity of the VPGs to identify significant obstruction. Results: The most frequent point of venous compression according to IVUS was the proximal left common iliac vein (70%; P < .05). Group II showed a greater prevalence of transpelvic (group I, 8.2%; group II, 74.5%; P < .001) and paravertebral collaterals (group I, 4.1%; group II, 45.1%; P < .001) on n MV. The femoral vein pressures at rest and after reactive hyperemia as well as the femorocaval gradient after reactive hyperemia (FCG-rh) and the femoral gradient after reactive hyperemia were significantly higher in group II (P » .001, P < .001, P » .002, and P » .006). The FCG-rh and the femoral gradient after reactive hyperemia presented the best diagnostic performance among the VPGs (P » .004 and P » .007) in n the receiver operating characteristic curve analysis, although no significant differences between them were found. All the gradients presented low values of sensitivity (<40%). negative predictive value (<60%). and accuracy (<30%). Logistic regression showed that FCG-rh was significantly independent of MV (OR, 8.1; P » .011) in identifying significant obstructions. Conclusions: There is correlation between the VPGs and significant obstructions with IVUS. However, this correlation does not translate to a good diagnostic performance of these VPGs. Only the FCG-rh added significant information to MV in identifying significant caval-iliac vein obstructions.

Correlation between venous pressure gradients and intravascular ultrasound in the diagnosis of iliac vein compression syndrome.

OBJECTIVE: The objective of this study was to evaluate the correlation between venous pressure gradients (VPGs) and intravascular ultrasound (IVUS) for the diagnosis of caval-iliac venous obstructions in patients with advanced chronic venous insufficiency. METHODS: Fifty patients with advanced chronic venous insufficiency symptoms (Clinical, Etiology, Anatomy, and Pathophysiology class 3 to 6) were prospectively submitted to multiplanar venography (MV) with intravenous pressure measurements and IVUS. The patients' lower limbs were divided accordingly: group I, limbs with <50% obstruction on IVUS (n = 49); and group II, limbs with ≥50% obstruction on IVUS (n = 51). Receiver operating characteristic curves compared the diagnostic performance of the VPGs. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy assessed the performance of VPGs in categories to determine the presence of significant obstruction. Logistic regression assessed the capacity of the VPGs to identify significant obstruction. RESULTS: The most frequent point of venous compression according to IVUS was the proximal left common iliac vein (70%; P < .05). Group II showed a greater prevalence of transpelvic (group I, 8.2%; group II, 74.5%; P < .001) and paravertebral collaterals (group I, 4.1%; group II, 45.1%; P < .001) on MV. The femoral vein pressures at rest and after reactive hyperemia as well as the femorocaval gradient after reactive hyperemia (FCG-rh) and the femoral gradient after reactive hyperemia were significantly higher in group II (P = .001, P < .001, P = .002, and P = .006). The FCG-rh and the femoral gradient after reactive hyperemia presented the best diagnostic performance among the VPGs (P = .004 and P = .007) in the receiver operating characteristic curve analysis, although no significant differences between them were found. All the gradients presented low values of sensitivity (<40%), negative predictive value (<60%), and accuracy (<30%). Logistic regression showed that FCG-rh was significantly independent of MV (OR, 8.1; P = .011) in identifying significant obstructions. CONCLUSIONS: There is correlation between the VPGs and significant obstructions with IVUS. However, this correlation does not translate to a good diagnostic performance of these VPGs. Only the FCG-rh added significant information to MV in identifying significant caval-iliac vein obstructions.

Randomized double-blinded study comparing medical treatment versus iliac vein stenting in chronic venous disease.

OBJECTIVE: Iliac vein stenting has emerged as the procedure of choice in the treatment of iliac vein obstruction (IVO). However, clinical outcomes have never been studied by a randomized clinical trial. Our purpose was to compare medical and endovascular treatment results in symptomatic chronic venous disease (CVD) patients with significant IVO documented by intravascular ultrasound (IVUS). METHODS: Patients with Clinical, Etiology, Anatomy, and Pathophysiology clinical class C3 to C6 and a visual analog scale for pain (VAS pain) score >3 were considered eligible. We randomly assigned limbs with ≥50% IVO on IVUS to undergo medical treatment alone or medical treatment plus iliac vein stenting. The patient and clinical physician were blinded. Primary outcomes included change from baseline in VAS pain score, Venous Clinical Severity Score, and 36-Item Short Form Health Survey quality of life questionnaire. Secondary outcomes included stent integrity, migration, and patency rates at 6 months. RESULTS: Of 207 CVD patients, 58 (28%) were eligible and eight (14%) were excluded; 51 of 85 class C3 to C6 limbs (60%) had ≥50% IVO by IVUS. Iliac vein stenting, in randomized patients, was 100% technically successful. At 6 months' follow-up, the mean VAS pain score declined from a median of 8 to 2.5 in patients receiving stents and from 8 to 7 in patients receiving only medical treatment (P < .001). The Venous Clinical Severity Score dropped from a median of 18.5 to 11 after stenting and from 15 to 14 with medical treatment (P < .001). The 36-Item Short Form Health Survey (0-100) improved from a total median score of 53.9 to 85.0 with stenting and 48.3 to 59.8 after medical treatment (P < .001). There was no stent fracture or migration, and the primary, assisted primary, and secondary patency rates were 92%, 96%, and 100%, respectively (median, 11.8; range, 6-18 months). CONCLUSIONS: Endovascular treatment of IVO with stenting is safe and promotes effective relief of symptoms and improvement in quality of life compared with medical treatment alone in symptomatic CVD patients. Our results echo those achieved in numerous previously published nonrandomized clinical series.

Randomized double-blinded study comparing medical treatment versus iliac vein stenting in chronic venous disease

OBJECTIVE:Iliac vein stenting has emerged as the procedure of choice in the treatment of iliac vein obstruction (IVO). However, clinical outcomes have never been studied by a randomized clinical trial. Our purpose was to compare medical and endovascular treatment results in symptomatic chronic venous disease (CVD) patients with significant IVO documented by intravascular ultrasound (IVUS).METHODS:Patients with Clinical, Etiology, Anatomy, and Pathophysiology clinical class C3 to C6 and a visual analog scale for pain (VAS pain) score >3 were considered eligible. We randomly assigned limbs with ≥50% IVO on IVUS to undergo medical treatment alone or medical treatment plus iliac vein stenting. The patient and clinical physician were blinded. Primary outcomes included change from baseline in VAS pain score, Venous Clinical Severity Score, and 36-Item Short Form Health Survey quality of life questionnaire. Secondary outcomes included stent integrity, migration, and patency rates at 6 months.

May-Thurner: diagnosis and endovascular management.

Common left iliac vein compression, otherwise known as May-Thurner (MT), is an anatomical risk factor for lower extremity deep vein thrombosis (DVT). MT refers to chronic compression of the left iliac vein against the lumbar spine by the overlying right common iliac artery. The compression may be asymptomatic. The syndrome is a clinical spectrum of physical findings and history plus the lesion. It is characterized by the varying degrees of venous hypertension. This can be non-thrombotic, combined with acute DVT or post-thrombotic. Traditionally, acute DVT was treated with standard anticoagulation and sometimes, thrombectomy. However these measures do not address the underlying culprit lesion of mechanical compression. Furthermore, if managed only with anticoagulation, patients with residual thrombus are at risk for developing recurrent DVT or post-thrombotic syndrome (PTS). Both retrospective and prospective studies have shown that endovascular management should be the preferred approach to dissolve proximal thrombus and to also treat the underlying compression with endovascular stent placement.

Criteria for detecting significant chronic iliac venous obstructions with duplex ultrasound.

OBJECTIVE: The purpose of this study was to determine the sonographic criteria for diagnosis of iliac venous outflow obstruction by assessing the correlation of this method with intravascular ultrasound (IVUS) in patients with advanced chronic venous insufficiency (CVI). METHODS: The evaluation included 15 patients (30 limbs; age, 49.4 ± 10.7 years; 1 man) with initial CVI symptoms (Clinical class, Etiology, Anatomy, and Pathophysiology [CEAP] classification, CEAP1-2) in group I (GI) and 51 patients (102 limbs; age, 50.53 ± 14.5 years; 6 men) with advanced CVI symptoms (CEAP3-6) in group II (GII). Patients from both groups were matched by gender, age, and race. The Venous Clinical Severity Score was considered. All patients underwent structured interviews and duplex ultrasound (DU) examination, measuring the flow phasicity, the femoral volume flows and velocities, and the velocity and obstruction ratios in the iliac vein. The reflux multisegment score was analyzed in both groups. Three independent observers evaluated individuals in GI. GII patients were submitted to IVUS, in which the area of the impaired venous segments was obtained and compared with the DU results and then grouped into three categories: obstructions <50%, obstructions between 50% and 79%, and obstructions ≥80%. RESULTS: The predominant clinical severity CEAP class was C1 in 24 of 30 limbs (80%) in GI and C3 in 54 of 102 limbs (52.9%) in GII. Reflux was severe (reflux multisegment score ≥3) in 3 of 30 limbs (10%) in GI and in 45 of 102 limbs (44.1%) in GII (P < .001). There was a moderately high agreement between DU and IVUS findings when they were grouped into three categories (κ = 0.598; P < .001) and high agreement when they were grouped into two categories (obstructions <50% and ≥50%; κ = 0.784; P < .001). The best cutoff points and their correlation with IVUS were 0.9 for the velocity index (r = -0.634; P < .001), 0.7 for the flow index (r = -0.623; P < .001), 0.5 for the obstruction ratio (r = 0.750; P < .001), and 2.5 for the velocity ratio (r = 0.790; P < .001). Absence of flow phasicity was observed in 62.5% of patients with obstructions ≥80%. An ultrasound algorithm was created using the measures and the described cutoff points with accuracy of 86.7% for detecting significant obstructions (≥50%) with high agreement (κ = 0.73; P < .001). CONCLUSIONS: DU presented high agreement with IVUS for detection of obstructions ≥50%. The velocity ratio in obstructions ≥2.5 is the best criterion for detection of significant venous outflow obstructions in iliac veins.

Criteria for detecting significant chronic iliacvenous obstructions with duplex ultrasound

The purpose of this study was to determine thesonographic criteria for diagnosis of iliac venous out flow obstruction by assessing the correlation of this method with intravascular ultrasound (IVUS) in patients with advanced chronic venous insufficiency (CVI). The evaluation included 15 patients (30 limbs; age,49.4 % 10.7 years; 1 man) with initial CVI symptoms (Clinicalclass, Etiology, Anatomy, and Pathophysiology [CEAP]classification, CEAP1-2) in group I (GI) and 51 patients (102limbs; age, 50.53 % 14.5 years; 6 men) with advanced CVI symptoms (CEAP3-6) in group II (GII). Patients from bothgroups were matched by gender, age, and race. The Venous Clinical Severity Score was considered. All patients underwent structured interviews and duplex ultrasound (DU) examination, measuring the flow phasicity, the femoral volume flowsand velocities, and the velocity and obstruction ratios in the iliac vein. The reflux multisegment score was analyzed in bothgroups. Three independent observers evaluated individuals inGI. GII patients were submitted to IVUS, in which the area ofthe impaired venous segments was obtained and comparedwith the DU results and then grouped into three categories: obstructions <50%, obstructions between 50% and 79%, andobstructions...