ENDOVASULAR MANAGEMENT of CHRONIC ILIOCAVAL OCCLUSION

Abstract

CONCLUSION D uring the past decade, venous outflow obstruction has become recognized as more relevant in CVD than previously anticipated, it has either a nonthrombotic (primary or idiopathic) or postthrombotic (secondary) cause. Either type can involve reflux, obstruction, or a combination of both. We should have a low threshold for extending investigation beyond duplex US evaluation of the lower extremity in CVI patients with a clinical severity beyond the demonstrated hemodynamic abnormalities, patients lacking another explanation for their symptoms, and patients with a history of DVT. MRV or CT may be good noninvasive screening tests if the appropriate technical expertise is available, while venography with the adjunctive use ofIVUSis the optimal technique for evaluation of iliac and caval pathology and also during intraoperative intervention. Endovenous therapy represents a significant component in the treatment of chronic venous insufficiency due to thrombosis. Theclinical options for treatment of residual obstruction, following DVT, now favorreconstruction of the native axial veins with self-expanding metallic stents. The evolution of the tools and techniques is ongoing, as the majority of the procedures have been adapted from arterial interventions. Because the venous system is characterized by lower pressure and lower flow state, compared with the arterial system, manipulations within veins are thrombogenic, and good technique is essential. Appreciating that stents represent a form of bypass and, therefore, require good inflow as well as outfow to remain patent is fundamental. Often, this is not obvious to the inexperienced physician, who underestimates the role of residual thrombus in distal veins or the importance of a stent extending into the IVC by one centimeter. Hybrid and complex open reconstructions have low long-term patency and should be used selectively as a last resort for resistant cases espicially (PTS), failed endovenous, severely symptomatic and, surgically fit. Iliocaval venous stenting alone is sufficient to control symptoms in the majority of patients with combined outflow obstruction and deep reflux. The patency rate is not related to the length of stented area or the placement of the stent across the inguinal ligament, but is dependent upon the etiology and whether the treated postthrombotic obstruction is occlusive or non-occlusive. Venous stenting can be performed with low morbidity and mortality, long-term high patency rate, and a low rate of in-stent restenosis. It resulted in major symptom relief in patients with chronic venous disease, which was not consistently reflected in any substantial hemodynamic improvement by conventional measurements. The beneficial clinical outcome occurred regardless of presence of remaining reflux, adjunct saphenous procedures, or etiology of obstruction. Many areas related to iliocvaval vein stenting require further study and clarification, including the role of IVUS imaging (used in only two studies), the degree of correctible stenosis, the relationship between silent and symptomatic obstructions, interrelationship of obstruction and reflux, and finally, a hemodynamic metric for obstruction.