Depending on chronicity and degree of collateralization, as well as anatomic location of the obstruction, thrombosis of the IVC can present with a range of clinical signs and symptoms. Patients with acute thrombosis may present with severe pain and lower extremity edema or even life- and limb-threatening sequelae such as phlegmasia cerulea dolens [3]. Neurologic symptoms such as sciatic pain and cauda equina syndrome have also been described [15].

Those with chronic obstructive pathologies tend to present more innocuously, and some are completely asymptomatic [16]. Many of these patients develop extensive collateral networks through the iliac, hemiazygous, and azygous venous networks [17] and may only become symptomatic if thrombus propagates caudally into the iliac or femoral veins [18]. Chronic lower extremity symptoms are generally classified by the revised CEAP grading system [19] and may range from mild-limb swelling to venous claudication and ulcer formation. Symptom severity may also be affected by concomitant lower extremity venous reflux and venous hypertension, which is more likely to lead to venous ulceration and pain than deep venous obstruction alone [20].

Clinical history should be focused on severity and chronicity of symptoms and the degree to which the patient’s lifestyle has been affected. Often times, patients have already attempted noninvasive therapies such as compression stockings and local wound care, as well as lower extremity venous procedures such as vein stripping or ablation, prior to presentation. Bilateral symptoms may be a clue suggestive of occlusion of the vena cava, rather than pathology limited to the iliofemoral veins. A history of hepatic insufficiency, even if seemingly unrelated, should arouse suspicion for suprahepatic caval involvement and Budd-Chiari syndrome [21]. The patient should be interviewed regarding personal and family history of DVT or hypercoagulability, as well as malignancy.

Physical examination should evaluate for signs of chronic venous disease, including swelling, lymphedema, varicose veins, lipodermatosclerosis, and ulcerations. Superficial varicosities may be noted on the proximal thigh or abdominal wall, suggestive of long-term central venous occlusion. Distal pulses should be assessed to rule out any associated peripheral arterial disease. Finally, lymphadenopathy or masses suggestive of malignancy may be appreciated during a thorough exam.

The majority of patients being evaluated for lower extremity venous disease will first be assessed with duplex ultrasonography. Testing is noninvasive and safe and provides both anatomic and physiologic information. The presence of DVT can be accurately and reliably assessed, as well as valvular incompetence leading to reflux [22]. Duplex ultrasound has been shown to be as accurate as descending phlebography in detecting reflux and is more easily tolerated by the patient [23]. However, the utility of duplex in the iliocaval system is somewhat limited due to user variability, patient body habitus, and presence of overlying bowel gas. When central occlusion is suspected, cross-sectional imaging is of critical importance. CT venography is accurate in identifying congenital anomalies such as caval interruption with azygous or hemiazygous continuation , duplicated or left-sided IVC, and intracaval membranous webs. Renal tumors, leiomyosarcomas, and pheochromocytomas, all of which can lead to direct or indirect caval obstruction, are also easily identified. Perhaps most importantly, the extent of obstruction can be assessed, specifically involvement of the renal and hepatic veins [24]. Due to the flow dynamics in the IVC, there may be artifact related to contrast timing and mixing of non-opacified blood, leading to false-positive results or “pseudothrombus ” [25, 26]. Magnetic resonance venography may obviate some of these issues, does not use ionizing radiation, and is the most reliable modality for evaluating tumor thrombus [24]. However, MRI is time-consuming and costly, and many patients have ferromagnetic implants which preclude them from undergoing the scan. Following some combination of ultrasound and cross-sectional imaging, the majority of patients will proceed to contrast venography in the angiography suite for further diagnostics and potential treatment.

For those patients with acute thrombosis of the IVC, systemic anticoagulation should be initiated in the form of unfractionated heparin, low molecular weight heparin, or fondaparinux [27]. Thrombolytic therapy may also be of benefit, specifically in reducing the incidence of post-thrombotic syndrome ; PTS may occur in upward of 50% of patients with iliocaval thrombosis [28, 29]. The role of anticoagulant therapy in chronic IVC obstruction is less clear, although most patients are maintained on systemic anticoagulation to prevent thrombus propagation and mitigate the risk of pulmonary embolism [3]. Duration of therapy is dependent on the underlying etiology; for those patients with inherited thrombophilia, lifelong anticoagulation may be necessary. There are no guidelines with regard to the various congenital IVC lesions and duration of anticoagulation therapy; thus the decision is tailored to the individual circumstance. However, if the underlying pathology is not corrected, then the thrombotic risk is not abated and presumably these patients should be anticoagulated for life as well. In contrast, if the thrombosis is related to an identifiable cause and that cause is treated, then in the absence of additional indications, anticoagulation may be reasonably stopped after 3 months’ duration [27]. As an example, tumor thrombus from a renal cell carcinoma extending into the IVC may be adequately treated by removal of the tumor and thrombectomy, and a short course of anticoagulation may be sufficient . Additional medical therapies are focused on symptomatic relief of the lower extremities: compression stockings or wraps, local wound care for venous ulcerations, and correction of any venous reflux pathology.

The decision to intervene on a patient with chronic IVC occlusion is made based on weighing individual patient risks and potential benefits. For patients with primary IVC thrombosis, surgery is reserved for those with debilitating or lifestyle-limiting symptoms who have failed medical therapy. Patients who have not improved with a course of compressive wraps and systemic anticoagulation should be considered for intervention. However, with more recent data suggesting good outcomes from less invasive endovascular techniques, the threshold for intervention has been somewhat lowered. In general, patients with CEAP scores of C₃–C₆ warrant intervention. It is important to note that patients with long-standing venous disease and symptoms of post-thrombotic syndrome may not improve clinically, due to ongoing infrainguinal pathology [30]. Patients with complications such as pulmonary embolism, venous ulcerations or gangrene, or renal or hepatic insufficiency should be intervened upon sooner rather than later. For patients with tumors causing IVC occlusion, either by means of tumor thrombus extension or direct caval compression, the indications for surgery should be primarily geared toward the desired oncological outcome. Our general treatment algorithm is outlined in Fig. 40.2.

For those patients deemed appropriate for intervention, open surgical reconstruction has been the traditional treatment of choice. Although this has now largely been relegated to a secondary option, there is still a role for open surgery when endovascular intervention has failed. There is also a role for open bypass in patients with traumatic IVC injuries not amenable to primary repair and for tumor resections which require resection of a portion of the IVC for oncologic clearance [31].

Surgical bypass should be performed using autologous tissue whenever possible, preferably with reversed greater saphenous vein. When no vein is available, the best choice for prosthetic conduit has been ePTFE [30], as outcomes for cryopreserved vein have been mediocre at short-term follow-up [32]. The best results for venous bypass in the central veins are with the Palma procedure or femoral-femoral crossover bypass (Fig. 40.3) [33]. Patency rates in the 70–80% range have been reported at 5-year follow-up with use of a high-quality venous conduit [34–36]. Although this is the patency standard to which central venous bypass should be compared, it is not appropriate for IVC obstruction because the crossover bypass relies on a contralateral iliac system with normal drainage for outflow.

For IVC obstruction, options include bypass from the iliac or femoral vein to the infra- or suprahepatic vena cava or resection and replacement with an interposition graft. The Mayo Clinic group has reported their experience with both scenarios [36]. They noted that early occlusion is common, occurring in 17% of cases. However, with re-intervention, patency at discharge was 96%. At 5-year follow-up, primary and secondary patency of iliocaval bypasses was 75% and 86%, respectively. For femorocaval bypass, the results were much worse, with 44% and 57% patency, respectively. This underscores the importance of a robust inflow to prevent graft thrombosis. In order to augment inflow, many have advocated the use of adjunctive arteriovenous fistulae (AVFs) , especially when femoral vein is used as inflow or a less than ideal conduit is used [30]. AVFs do increase flow in experimental models [37, 38], but no substantial clinical data exists and the use is left to surgeon preference. In general, AVF should be used in prosthetic grafts utilizing the femoral vein as inflow, as well as iliocaval grafts longer than 10 cm [39]. Other factors adversely affecting patency have also been well defined in this group; use of prosthetic grafts, smoking, and male gender have all been associated with poorer outcomes [36]. Use of adjunctive AVF could also be considered in these cases, although there is no data to support this other than anecdotal evidence.

For patients in need of IVC replacement during tumor resection, the results have been positive. In one study of patients undergoing ePTFE interposition grafts, 27/29 grafts remained patent at an average of 2.8-year follow-up, and one of the failures was due to tumor recurrence at 6 years [40]. These patients have high perioperative morbidity and mortality, in line with the expected outcomes from the tumor resection itself. No adjunctive arteriovenous fistulae were constructed and are generally not needed when the inflow is from the infrahepatic vena cava.

In recent years, the use of endovenous stents for central venous occlusive disease has increased significantly with good results and minimal morbidity [41] and should be considered first-line therapy for most patients. Despite the chronicity of occlusion, technical success is achievable in the majority of cases.

Percutaneous access is gained through the femoral, greater saphenous or popliteal vein based on individual clinical situation. Bilateral access may be of some benefit in certain scenarios. The lower extremity may be edematous, and ultrasound guidance is recommended. Preoperative diagnostics including duplex ultrasound and cross-sectional imaging such as CT venography have usually been performed prior to entering the angiography suite and can help guide access and therapy decisions. Contrast venography is then performed to further characterize the lesion, although venography has a sensitivity of only around 50% and intraluminal lesions are easily missed [42]. Chronic, obstructive lesions are characterized by the presence of multiple, robust collateral vessels, although these may only be present in approximately one third of cases [41]. Multiple projections may be needed to identify the native, obstructed vein among many collaterals. Because of these limitations, intravascular ultrasound (IVUS) has become the gold standard for evaluating venous pathology and should be used whenever feasible as an adjunct to traditional subtraction venography. IVUS can reliably detect intravascular webs and membranes, accurately measure diameter, and distinguish between intraluminal obstruction and extrinsic compression [41, 42]. IVUS also limits contrast usage and radiation exposure to both the operator and the patient.

Once the lesion has been appropriately characterized, it is crossed using a wire-catheter combination of the surgeon’s preference. Often this is possible with a 0.035 in. stiff or floppy glide wire and angled glide catheter (Terumo Medical, Somerset, NJ). If the lesion is not easily navigable in this manner, a looped wire technique may also be employed (Fig. 40.4) [43]. It is imperative to use either IVUS or contrast injection to confirm appropriate reentry into the IVC after crossing. Sequential balloon pre-dilatation is then performed to allow for stent deployment. Large, self-expanding Wallstents (Boston Scientific, Marlborough, MA) work well and are sized based on IVUS diameter measurements. Wallstents can foreshorten significantly on post-dilatation, so they should be deployed with generous overlap to avoid gaps [16]. Stents can be deployed across the renal or hepatic veins with no clinical sequelae [16]. Completion IVUS should be used to ensure all sites of disease have been appropriately covered and there is no residual stenosis which may serve as a nidus for recurrence.