Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3775_Библиотеки_им_академика_М_И_Перельмана

Chronic venous disease and venous thrombosis have been reported more frequently on the left lower limb rather than on the right one: a fact that already Virchow attributed to the possible com­pression of the left iliac vein by the crossing iliac artery [1, 2]. At the same time, cadaver dissec­tions reported a surprisingly high percentage of iliac intraluminal lesions that affect iliac venous drainage, in up to 30% of unselected cases [3, 4]. These intraluminal lesions have been described as webs, ridges, velums, bridges, quilted wall adhesions, and even total occlusion [5].

The genesis of these lesions remains a matter of debate, combining the possible traumatic effect of the nearby artery pulsation with a pos­sible ontogenesis. Magnetic resonance imaging points out the possible overlapping presence of intrinsic and extrinsic causes of iliac drainage impairment in up to 66% of patients [6].

fundamental. Typical presentation includes recurrent deep venous thrombosis, lower limb swelling and pain, ulceration, venous claudica­tion, and chronic venous disease.

Non-thrombotic iliac vein lesion (NIVL) can present an acute or chronic onset. The first one is easier to detect since it is easily associated with sudden leg edema and redness. The chronic con­dition is more difficult to be detected and requires a full investigation of patient history, physical examination, and diagnostic imaging. In the diagnostic process, it must be remembered that also trauma, surgery, recent catheterization radia­tion, and malignancies can be involved in iliac venous drainage impairment.

As suggested by Gaweesh [12, 13], pelvic obstruction could be the reason for varicose veins in patients without a history of deep venous thrombosis, thereby offering stenting of the iliac

veins as a solution. If this obstruction hypothesis was true, it would introduce a new industry of treatment for simple varicose veins. Recent investigations with air plethysmography have questioned the obstruction hypothesis by demon­strating improved gravitational venous drainage in patients with varicose veins. The venous drain­age index (VDI) in mL/s was faster, presumably because the outflow pathways were larger as a result of the reflux [14]. Further investigations on a tilt table have defined a cutoff point in the venous drainage index (VDI) to differentiate between proximal obstruction on one hand and normal subjects or patients with varicose veins without pelvic obstruction on the other [15]. This simple investigation could be performed as a first step, noninvasive screening test. After demon­strating a prolonged VDI, the site and nature of the obstruction can be investigated further using the more invasive imaging techniques like abdominal or transvaginal ultrasound, contrast venography, CT, MRI, or intravenous ultrasound.

Endocavitary (transvaginal or transrectal) examination by a 5–7.5 MHz probe is the pri­mary way to visualize pelvic varicosities [17]. Phlebography has been considered the refer­ence imaging technique for pelvic congestion syndrome assessment, to be performed after a preliminary ultrasound assessment [18]. Nowadays, after the improvement of tech­niques and knowledge around the application of duplex, this method seems to have become the gold standard [19].

The introduction of intravascular ultrasound (IVUS) technique has supported previous finding in demonstrating that the diagnostic sensitivity of venography for non-thrombotic iliac vein lesion (NIVL) is only on the order of about 50% [20]. Considering the absence of radiation and its sen­sitivity above 90%, intravascular ultrasound (IVUS) is now considered a diagnostic standard in this type of lesions.