Chapter 59 - Importance, etiology, and diagnosis of chronic proximal venous outflow obstruction

Abstract

Symptoms of proximal chronic venous obstruction may vary greatly, ranging from moderate swelling and pain to discoloration and stasis ulcers. Symptoms are also influenced by any concomitant deep or superficial reflux. Obstruction plays an important role in the clinical expression of chronic venous disease, especially as pain. Less common causes of chronic blockage of the iliaccaval vein include benign or malignant tumors, retroperitoneal fibrosis, iatrogenic injury, irradiation, cysts, and aneurysms. Relief of symptoms is immediate, following successful stenting of malignant obstructions. The long-term outcome appears to depend largely on the progress of the tumor. Iliocaval stenosis due to retroperitoneal fibrosis has been treated successfully by stenting. Ultrasound investigation and outflow fraction determinations by plethysmographic methods have been shown to be unreliable and play only a limited role. Although abnormal plethysmography findings may indicate obstruction to the venous outflow, significant blockage may exist in the presence of normal findings. Even the invasive pressures (i.e., hand/foot pressure differential and reactive hyperemia pressure) increase and indirect resistance calculations appear insensitive, and do not define the level of obstruction.