Single-session total endovascular iliocaval reconstruction with stent grafting for the treatment of inferior vena cava agenesis and concurrent iliac venous aneurysm rupture.

Iliac venous aneurysms are rare vascular abnormalities that may be manifested by abdominal masses, pelvic tenderness, or hypovolemia and may lead to rupture, thrombosis, pulmonary embolism, paradoxical embolism, or death. Inferior vena cava agenesis, like venous aneurysm, is an uncommon condition that may present with deep venous thrombosis. This report describes a patient with inferior vena cava agenesis and iliac venous aneurysm rupture treated with emergent iliocaval reconstruction and endovascular stent graft placement.

Iliac venous aneurysms are vascular abnormalities that may lead to rupture, thrombosis, pulmonary embolism, or death. Described in the setting of trauma, venous aneurysms have been treated using balloon angioplasty, stenting, staple plication and resection over a balloon mandril, aneurysmectomy, and lateral venorrhaphy.2, 3 Inferior vena cava (IVC) agenesis, like venous aneurysm, is an uncommon condition. Thought to arise from embryologic dysgenesis or early IVC thrombosis, the spectrum of IVC agenesis and hypoplasia may present with deep venous thrombosis. Such patients have been treated conservatively with anticoagulation and compression stockings or aggressively with open thrombectomy and caval reconstruction or endovascular iliocaval reconstruction.4, 5 This report describes a patient, who consented for this publication, with IVC agenesis and iliac venous aneurysm rupture treated with emergent iliocaval reconstruction and endovascular stent graft placement.

Case report

Institutional Review Board approval was not required for the preparation of this report. The patient's consent was obtained for creation of this report.

A 49-year-old man with history of left deep venous thrombosis after rotator cuff repair in 2008 managed with anticoagulation presented after “bending over, feeling a popping sensation, and developing right lower quadrant pain.” In the emergency department, heart rate was 143 beats/min and blood pressure was 78/46 mm Hg. Hemoglobin concentration was 6.6 mg/dL. Computed tomography (CT) of the abdomen and pelvis demonstrated absence of the infrarenal IVC with bilateral common and external iliac venous aneurysms and a right-sided 20- × 14- × 9-cm retroperitoneal hematoma concerning for venous aneurysm rupture or a hemorrhagic malignant neoplasm (Fig 1). There was high attenuation material within both common iliac veins, thought to represent acute deep venous thromboses. Right common iliac arteriography showed no extravasation, pseudoaneurysm, nor neovascularity to suggest neoplasm. Right ascending iliocaval venography revealed a venous aneurysm involving the common and external iliac vein, measuring up to 5.5 cm (Fig 2). Extravasation was seen at the mid-right external iliac vein with eccentric thrombus within the periphery. Fifteen endovascular biopsy specimens were obtained throughout multiple areas of the venous aneurysm using 5.5F forceps (Cordis, Fremont, Calif), confirming the presence of acute thrombus with no neoplastic cells.

Fig 1

A, Axial computed tomography (CT) image with intravenous administration of contrast material demonstrating the ruptured right common iliac vein aneurysm (white arrow) with surrounding retroperitoneal hematoma (arrowheads), as well as a left common iliac vein aneurysm (black arrow). B, Coronal CT image showing the ruptured right iliac vein aneurysm (arrow) with adjacent retroperitoneal hematoma (arrowheads). C, Dilated retroperitoneal collateral veins (arrowheads) with a diminutive inferior vena cava (IVC; white arrow). D, Dilated azygos (arrow) and hemiazygos (arrowhead) veins with absence of the IVC consistent with IVC agenesis.

Fig 2

A, Right femoral iliac arteriography showing no extravasation, arteriovenous fistula, or pseudoaneurysm of the external (arrow) or internal (arrowhead) iliac arteries. B, Right ascending saphenous venography demonstrating a 5.5-cm ruptured common and external iliac vein aneurysm (arrowheads). There are filling defects within the right common femoral vein consistent with thrombus (arrow). C, A left common iliac vein aneurysm is appreciated as well (arrowhead). D, Serial balloon angioplasty of the inferior vena cava (IVC, arrow) and iliac veins. E, Placement of 20- × 55-mm Wallstent endoprostheses in the suprarenal and infrarenal IVC, a 20- × 50-mm Gianturco Z-stent at the renal confluence (arrow), and 14- × 90-mm Wallstent endoprostheses in the IVC into the proximal common iliac veins. F, Ruptured right iliac vein aneurysm excluded with overlapping 16- × 156-mm and 16- × 93-mm Medtronic Endurant II stent grafts (arrowheads). G and H, Completion venography showing restoration of in-line flow from the right common femoral vein to the suprarenal IVC with exclusion of right iliac vein aneurysm (arrowheads).

As the patient remained stable, with blood pressure of 102/74 mm Hg, and given the extravasation, a decision was made to endovascularly treat the aneurysm using stent graft placement. In the setting of IVC agenesis or hypoplasia, it was thought that iliocaval reconstruction, with good venous outflow, would be required to maintain stent graft patency. From a right internal jugular (IJ) approach, a NaviCross guiding catheter (Terumo Medical Corp, Tokyo, Japan) and stiff angled Glidewire (Terumo Medical Corp) were used to traverse the occluded IVC. Venous integrity was confirmed using contrast agent injections (Isovue 300; Bracco Diagnostics, Monroe Township, NJ) in conjunction with intravascular ultrasound (IVUS) (Volcano Medical, San Diego, Calif). A baseline activated clotting time (ACT) was obtained, 5000 units of unfractionated heparin were given, and the ACT was repeated at 30-minute intervals with goal ACT of 200 to 250 maintained with repeated heparin boluses. From a right great saphenous vein approach, mechanical thrombectomy of the left popliteal, femoral, common femoral, and external iliac veins was performed using the Indigo reperfusion system (Penumbra, Alameda, Calif). Angioplasty of the right common iliac vein and IVC was then performed using 14-mm and 16-mm balloons (Bard PV, Tempe, Ariz) because of concomitant multifocal stenoses with thrombus. Next, angioplasty of the entire IVC was performed with an 18-mm balloon; 20- × 55-mm Wallstents (Boston Scientific, Marlborough, Mass) were then deployed in the hepatic IVC, below the hepatic vein confluence and within the infrarenal IVC. Overlapping 20-mm × 5-cm Gianturco Z-stents (Cook Medical, Bloomington, Ind) were placed at the level of the renal veins to preserve renal vein inflow.

Using the double barrel technique, two 14- × 90-mm Wallstents were deployed simultaneously in the inferior IVC extending into the common iliac veins. From a right IJ vein approach, mechanical thrombectomy of the right lower extremity was performed using the AngioJet thrombectomy device (Boston Scientific). To exclude the ruptured right iliac vein aneurysm, overlapping 16- × 16- × 156-mm and 16- × 16- × 93-mm Endurant II stent grafts (Medtronic, Minneapolis, Minn) were delivered across the right-sided aneurysm, extending from the inguinal ligament into the common iliac vein Wallstent. Exclusion of the ruptured aneurysm was confirmed with venography and IVUS.

Additional attempts were made to remove the remaining thrombus within the lower extremity using the AngioJet thrombectomy device with suboptimal results, prompting the decision to perform thrombolysis. A 5F UniFuse thrombolysis catheter (AngioDynamics, Latham, NY) was placed into the left lower extremity extending from the left common iliac vein to the left popliteal vein. Tissue plasminogen activator was administered at 1 mg/h with heparin infusion at 500 units/h.

After 24 hours of thrombolysis, left iliofemoral venography was performed, revealing complete resolution of thrombus throughout the left popliteal and femoral veins, with thrombus remaining within the left common femoral and external iliac vein aneurysms. There was no evidence of hemorrhage from the left iliac venous aneurysm. To exclude the thrombus and to promote flow from the left lower extremity, 14- × 60-mm, 16- × 60-mm, and 18- × 60-mm overlapping Wallstents were deployed. Postdeployment venography demonstrated brisk in-line flow. Completion venography demonstrated excellent in-line flow throughout the iliocaval reconstruction without significant residual stenosis, thrombosis, hemorrhage, or aneurysm opacification (Fig 3); 90 mg of enoxaparin (Sanofi-Aventis, Paris, France), 300 mg of clopidogrel (Bristol-Myers Squibb, New York, NY), and 81 mg of aspirin were administered. Repeated CT of the abdomen and pelvis with intravenous administration of contrast material demonstrated a stable 20- × 14- × 9-cm right retroperitoneal hematoma with widely patent iliocaval stents and stent grafts (Fig 3). The patient was discharged 5 days later.

Fig 3

A and B, Completion venography demonstrating brisk in-line flow from both femoral veins to the suprarenal inferior vena cava (IVC) without stenosis, thrombus, or aneurysm. Both the ruptured right iliac vein aneurysm (B; arrowheads) and left iliac vein aneurysm have been excluded. The Gianturco Z-stent is seen at the renal confluence (A; arrowheads). C, Coronal reformatted computed tomography (CT) image demonstrating the widely patent iliocaval reconstruction. D, Coronal reformatted CT image showing the patent iliac vein stent graft (white arrowheads) with adjacent retroperitoneal hematoma (arrow).

The patient was seen in the interventional radiology clinic 2 weeks later without complaints. The patient was transitioned from enoxaparin to warfarin. Repeated CT of the abdomen and pelvis, performed at 3 months, demonstrated a patent iliocaval system. Duplex ultrasound of both lower extremities, also performed at 3 months, showed no evidence of deep venous thromboses within the lower extremities. Repeated conventional venography, performed at 4 months, showed patent iliocaval stents and stent grafts.

Discussion

Although it is not often associated with iliac venous aneurysms or venous rupture, iliocaval thrombosis is a common cause of morbidity in otherwise healthy patients. The indications for iliocaval reconstruction include venous occlusion in the setting of recurrent deep venous thrombosis, post-thrombotic syndrome, and curtailment of habitual activities. This case illustrates that iliocaval reconstruction may also be used as part of a strategy to treat ruptured venous aneurysms in the setting of iliocaval agenesis. The iliocaval reconstruction technique has been described elsewhere. Briefly, after bilateral great saphenous vein and right IJ vein access is obtained, a vertebral tip catheter and straight stiff guidewire are used to perform recanalization. If initial recanalization is unsuccessful, sharp recanalization using a BRK-1 trans-septal needle (St. Jude Medical, Saint Paul, Minn) and loop snare is performed. Once through-and-through access is obtained, tract integrity is evaluated using contrast material or carbon dioxide injections in conjunction with IVUS. The IVC is then dilated to 18 mm, the common iliac veins are dilated to 16 mm, and the external iliac and common femoral veins are dilated to 14 mm. Next, 18- to 22-mm self-expanding stents are deployed in the IVC with common iliac stents deployed such that the square of the stent diameter is half the square of the stented IVC diameter, rounded up to the next available size. Postprocedure angioplasty, venography, and IVUS are performed. Afterward, the inflow is evaluated from an IJ approach, and angioplasty is performed as necessary. Iliocaval reconstruction is technically successful in 83%. The 4-year primary and secondary patency rates are 35% and 72% for iliac vein recanalization and 40% and 80% for IVC recanalization, respectively. Although additional studies are needed to further refine iliocaval reconstruction techniques and describe long-term patency, this case emphasizes that endovascular therapy is a potential treatment alternative for complex venous disease including IVC agenesis and concomitant iliac venous aneurysm rupture.