Role of IVUS in Management of Iliocaval Obstruction
Role of IVUS in Management of Iliocaval Obstruction
To assess the role of IVUS in

 1. Providing diagnostic important data as: luminal diameters, cross-sectional area,
 assessment of potential thrombus volume which enables optimal choice of appropriate
 angioplasty technique, endovascular device guidance, and their impact on procedural
 technical success and patency rates.

 2. comparing diagnostic accuracy of intravascular ultrasound (IVUS) with multiplanar
 venography and CT venography for iliocaval obstruction.
Acute and chronic venous disorders of the lower extremities affect millions of people and
 cause substantial disability. Surgeons and pathologists identified the presence of
 'spur-like' abnormalities of the left common iliac vein, these abnormalities were
 hypothesized to result from compression and/or irritation from the adjacent crossing right
 common iliac artery. In the 1990s, physicians, starting to perform catheter-directed
 thrombolysis to treat extensive deep vein thrombosis (DVT), observed that about 50% of
 patients had an iliac vein stenosis.Treatment is aimed at ameliorating the symptoms and,
 whenever possible, at correcting the underlying abnormality. Graduated compression is the
 cornerstone of modern therapy. Deep system disease is often refractory to treatment, but
 superficial system disease can usually be treated by ablating the refluxing vessels.
 Effective venous return from the lower extremities requires the interaction of the heart, a
 pressure gradient, the peripheral muscle pumps of the leg, and competent venous valves. In
 the absence of pathology, this system functions to reduce venous pressure from approximately
 100 mm Hg to a mean of 22 mm Hg within a few steps.

 Nonthrombotic venous compression patients with left common iliac vein compression can present
 in the 2nd or 3rd decade of life and are more common in women. Patients can have limb pain,
 limb swelling, ipsilateral chronic venous insufficiency, lipodermatosclerosis, recurrent
 superficial venous thrombophlebitis, and venous claudication.

 Thrombotic iliofemoral venous compression with a predisposing anatomic configuration with a
 prothrombotic physiological state can present with acute pain and swelling of the left lower
 extremity consistent with an acute iliofemoral DVT mostly phlegmasia cerulea dolens . In the
 acute phase, patients with a patent foramen ovale can also present with a pulmonary embolism,
 cryptogenic stroke, with or without pulmonary embolism, or systemic arterial embolism.

 The abnormalities in venous physiology associated with chronic venous disease, and their
 quantification by diagnostic tests, are also considerably more complex than for PAD. With CVD
 one must gauge the effects of obstruction and/or reflux in a vascular bed uniquely designed
 to return venous blood to the heart against gravity with the aid of a peripheral muscle pump
 and in phase with respiratory mechanics.

 Duplex ultrasound (DUS) is initial diagnostic test. The criteria include: poststenotic
 turbulence, as indicated by a mosaic velocity profile, abnormal Doppler signal at the area of
 stenosis, continuous flow with the Valsalva maneuver, and sluggish with no spontaneous flow
 and poor augmentation and no respiratory phasicity. But there is limitations as obesity
 ,casts, dressings, open wounds, Patients with severe edema/swelling and limited patient
 mobility.

 Cross-sectional imaging includes computed tomographic venography (CTV) with venous phase
 contrast or magnetic resonance venography (MRV).

 Catheter-based phlebography traditionally is considered to be the most definitive technique
 for the evaluation of venous obstruction, supplemented with direct pressure measurements
 across an area of perceived stenosis in order to determine whether a pressure gradient
 exists.

 Intravascular ultrasound (IVUS) uses a catheter-based ultrasound probe that enables
 high-resolution evaluation of the vein wall and internal venous architecture in 360. IVUS is
 more sensitive than phlebography for the detection and characterization of iliac vein
 pathology. This would be expected since IVUS gives a 360 image versus a single plane image
 shown by standard phlebograms. Intravascular ultrasound also identifies intraluminal
 trabeculations, septations, webs, and wall thickening, which can be minimized or missed on
 standard phlebography, plus reduced radiation exposure in contrast to other modalities.

 IVUS is better in evaluating lesion morphology, accurate assessment of luminal dimensions,
 transmural lesion characteristics. Delineation by IVUS of the spatial distribution of the
 lesion in a concentric or eccentric pattern and the presence of a soft (fibrous) or hard
 (calcified) plaque may influence the choice of endovascular therapy as well as predict the
 risk of immediate or late complications (ie, perforation, thrombosis, restenosis). Evaluation
 of lesion volume before and after the procedure by IVUS provides a quantitative method to
 estimate the amount of lesion debulking or displacement and a reference point from which to
 assess the lesion recurrence/restenosis. IVUS also fulfills many of the necessary
 requirements of a guidance system for endovascular procedures, namely precise delivery and
 positioning of stents within target lesions. IVUS is particularly helpful in assessing the
 relationship of the ostia of branch vessels to the lesion that can be used as landmarks
 during procedures.
Inclusion Criteria:

 -  1-acute iliocaval obstruction 2-chronic iliocaval obstruction with CEAP clinical class
 3-6 3- acute on top of chronic iliocaval obstruction with CEAP clinical class 3-6
 4-symptomatic acute femoro-iliocaval occlusion who underwent successful thrombolysis

 Exclusion Criteria:

 1 - concomitant peripheral arterial disease in the affected limb. 2-life expectancy less
 than 5 years. 3- pregnancy 4- malignancy 5-raised renal chemistry 6-pelvic fibrosis 7-
 contraindication to anti-coagulation therapy. 8-congenital venous malformations 9-Not
 providing informed consent 10-Any concurrent disease as heart failure