Inferior Vena Cava Stent Placement Research Articles

Antithrombotic Therapy for Inferior Vena Cava Stenting of Malignant Inferior Vena Cava Syndrome: A Questionnaire Study of Japan Interventional Radiology Study Group (JIVROSG)

Abstract Purpose The aim of this study was to evaluate the differences in antithrombotic therapy policies for inferior vena cava (IVC) stent placement among institutions and interventional radiologists in Japan. Materials and Methods The cross-sectional online-based questionnaire was conducted between December 2022 and January 2023, and a total of 114 institutions were included in this study. The questionnaire contained eight questions that were grouped into three sections: (1) whether IVC stents have been performed or not, (2) the number of IVC stent placements, and (3) the basic strategy of antithrombotic therapy for pre-, intra-, and post-IVC stent placement. Results Of the 114 institutions, 38 responses (33%) were collected. Twenty-four of the 38 institutions (63%) had performed IVC stent placement during the study period. The mean number of IVC stent placements during the study period was 3.4 cases per institution. The most frequently selected antithrombotic therapeutic strategies pre-, intra-, and post-stenting were no antithrombotic therapy (62.5%), anticoagulation therapy (54.2%), and no antithrombotic therapy (41.7%). Conclusion This study has revealed there is no consensus regarding antithrombotic therapy for IVC stent placement in Japan. The results of this study may contribute to our understanding of the status of antithrombotic therapy for IVC stent placement. Future prospective studies are warranted to clarify the periprocedural antithrombotic therapy for IVC stent placement.

Necessity of Prophylactic Anticoagulation Therapy Following Inferior Vena Cava Stent Placement in Patients with Cancer.

Although percutaneous stent placement for malignant inferior vena cava syndrome is a highly feasible and effective treatment option, there is no clear evidence for the necessity of prophylactic anticoagulation therapy after inferior vena cava stent placement. This study retrospectively evaluated the necessity of prophylactic anticoagulation following inferior vena cava stent placement in patients with malignant inferior vena cava syndrome. The data of 54 patients (28 men and 26 women; median age 61.2 years) with malignant inferior vena cava syndrome who received inferior vena cava stent placement between 2011 and 2021 were retrospectively reviewed. Prophylactic anticoagulation was administered to 15 of 54 patients (27.8%) following stent placement. Symptom recurrence rates at 1 and 2 months after stent placement were compared between patients with and without prophylactic anticoagulation using Gray relational analysis. The timeline of symptom recurrence, survival time, and adverse events were also evaluated. At 1 and 2 months, symptom recurrence rates were 48.6% and 71.4%, respectively, in patients with prophylactic anticoagulation and 28.3% and 37.0%, respectively, in patients without prophylactic anticoagulation. The overall median follow-up duration was 27 days and that of the patients with and without prophylactic anticoagulation was 37 and 25 days, respectively. The median survival times of patients with and without anticoagulation therapy were 69 and 30 days, respectively (p = 0.236). No procedure-related complications occurred. There was no significant difference in the symptom recurrence rates after inferior vena cava stent placement with or without prophylactic anticoagulation in this study.

3:54 PM Abstract No. 88 Safety and efficacy of Gianturco tracheobronchial z-stent placement for recanalization in patients with inferior vena cava occlusion

To evaluate the technical success and safety of Gianturco Z-stent placement in patients with occlusion of the inferior vena cava (IVC). Between January 2010 and July 2019, a retrospective review was performed including patients who underwent placement of Gianturco tracheobronchial Z-stents (Cook Medical, Bloomington, IN) in the IVC for treatment of IVC occlusion. Indication for placement, technical success, primary patency, and clinical success as measured by symptomatic improvement were recorded. Patients received clinical follow-up and computed tomographic (CT) imaging for patency evaluation initially at 1 to 4 months and yearly thereafter. Z-stent placement was performed in the IVC of 20 patients (median, age, 47 years; range, 21-88 years; percent female, 50%). Indications for IVC stent placement consisted of non-malignant occlusions in 13 patients and malignant occlusions in 7 patients. Technical success was achieved in all patients; no procedure-related major adverse events were observed. Data on clinical success was available in 11 of 13 patients treated for non-malignant IVC occlusions at initial follow-up (mean follow-up length, 1.4 months; range, 1-2 months) demonstrating symptomatic improvement in 100% (11/11) of patients. Patency of IVC stents was maintained in 92.3% (12/13) of patients treated for non-malignant occlusions (mean follow-up length, 1.5 months; range, 1-4 months). Longer-term follow-up was available in 5 patients with non-malignant occlusions and all (5/5) demonstrated maintained patency of IVC stents (mean follow-up length, 21.8 months; range, 12-45 months). Of the patients treated for malignant IVC occlusion for whom data was available, symptomatic improvement was achieved in 100% (4/4 patients; median follow-up length, 3.5 months; range, 2-17 months) and patency of the IVC stent was maintained in 100% (5/5 patients; median follow-up length, 5 months; range, 2 weeks-19 months). Through available follow-up, off-label placement of Gianturco tracheobronchial Z-stents in the IVC appears safe for patients with both non-malignant and malignant occlusions. Long-term follow-up will be necessary in evaluating the efficacy and durability of the intervention.

In Situ Left Lateral Sectionectomy in Deceased Donor Liver Transplantation: Could This Be Another Solution for a Large-for-Size Graft? A Case Report

BackgroundLarge-for-size (LFS) graft should be avoided when performing an adult deceased donor liver transplantation (DDLT) as it is associated with abdominal compartment syndrome, severe graft injury, and primary graft nonfunction. When inadvertently facing with LFS graft intraoperatively, the most commonly reported approach has been a surgical reduction of the right lobe despite its technical difficulty in addition to ongoing coagulopathy after graft reperfusion. We report a case where we performed a left lateral sectionectomy instead of a right lobe modification. Case ReportA 44-year-old 58.4 kg female patient was admitted with drug-induced acute hepatic failure and underwent an emergency DDLT. The donor was a 51-year-old 60.0 kg man. At the time of procurement, the liver was noted to be hypertrophic. The estimated graft/recipient weight ratio was 3.49%. After completing the vascular and bile duct anastomosis, the abdomen could not be closed due to its large graft size. Because of the hypertrophic left lateral lobe and ongoing coagulopathy, we decided to perform an in situ left lateral sectionectomy rather than right posterior sectionectomy or right hemihepatectomy. The next day, the liver function failed to improve, and the patient’s blood pressure began to decline gradually. Computed tomography showed severe inferior vena cava (IVC) compression by the graft, and the patient underwent transjugular IVC stent placement. Soon after, the patient’s blood pressure improved and liver function gradually normalized. The patient was discharged uneventfully on postoperative day 45. ConclusionUnder specific conditions, in situ left lateral sectionectomy is a solution for unexpected LFS graft during DDLT.

Lower Extremity Venous Stent Placement: A Large Retrospective Single-Center Analysis.

To study short-term and long-term outcomes of lower extremity venous stents placed at a single center and to characterize changes in vein diameter achieved by stent placement. A database of all patients who received lower extremity venous stents between 1996 and 2018 revealed 1,094 stents were placed in 406 patients (172 men, 234 women; median age, 49 y) in 513 limbs, including patients with iliocaval stents (9.4% acute thrombosis, 65.3% chronic thrombosis, 25.3% nonthrombotic lesions). Primary, primary assisted, and secondary patency rates were assessed for lower extremity venous stents at 1, 3, and 5 years using Kaplan-Meier analyses and summary statistics. Subset analyses and Cox regression were performed to identify risk factors for patency loss. Vein diameters and Villalta scores before and up to 12 months after stent placement were compared. Complication and mortality rates were calculated. Primary, primary assisted, and secondary patency rates at 5 years were 57.3%, 77.2%, and 80.9% by Kaplan-Meier methods and 78.6%, 90.3%, and 92.8% by summary statistics. Median follow-up was 199 days (interquartile range, 35.2-712.0 d). Patency rates for the subset of patients (n= 46) with ≥ 5 years of follow-up (mean ± SD 9.1 y ± 3.4) were nearly identical to cohort patency rates at 5 years. Patients with inferior vena cava stent placement (hazard ratio 2.11, P < .0001) or acute thrombosis (hazard ratio 3.65, P < .0001) during the index procedure had significantly increased risk of losing primary patency status. Vein diameters were significantly greater after stent placement. There were no instances of stent fracture, migration, or structural deformities. In patients with chronic deep vein thrombosis, Villalta scores significantly decreased after stent placement (from 15.7 to 7.4, P < .0001). Perioperative mortality was < 1%, and major perioperative complication rate was 3.7%. Cavo-ilio-femoral stent placement for venous occlusive disease achieves improvement of vein disease severity scores, increase in treated vein diameters, and satisfactory long-term patency rates.

SAT-167 THE CASE OF A NOT SO ABSENT INFERIOR VENA CAVA

Background: Congenital absence of the inferior vena cava (IVC) is an extremely rare condition, which may be congenital or due to perinatal thrombosis, is associated with lower limb deep vein thrombosis risk, non-healing venous ulcers and the development of collateral venous drainage systems. We report a case of a congenitally absent IVC in a patient with renal failure and subsequent renal transplantation, with recurrent acute kidney injury (AKI) related to exercise, whom underwent successful IVC stenting with restoration of venous flow. Case: The patient was a 28-year-old female with a diagnosis of congenital absence of her IVC, with venous drainage of her lower limbs achieved by markedly dilated ascending lumbar veins which drained into an enlarged azygous vein. She had a history of chronic kidney disease with renal transplant at age 4, which failed after recurrent unexplained episodes of acute tubular necrosis (ATN). After her second transplant at age 26 she continued to have recurrent episodes of biopsy proven ATN, which were subsequently found to be related to exercise with creatinine levels of more than 300µmol/L from a baseline of 113µmol/L. Pelvic angiography demonstrated abrupt pinching of the enlarged right lumbar vein at the L4/L5 vertebrae with straight leg raise and subsequent flow of blood into the left lumbar vein. The dilated ascending lumbar veins in the retroperitoneum, which drain the renal transplant, course between the psoas muscle and the lumbar vertebral bodies. During exercise, it is hypothesised that there is venous hypertension in the kidney due to outflow obstruction from compression of the ascending lumbar veins (from psoas muscle compression) at the level of L4/L5. There is subsequent decreased venous return, leading to arterial hypotension, poor renal perfusion, and AKI. These episodes recovered with intravenous fluids and bed rest. Botox injections into the psoas muscles were minimally beneficial in reducing exercise related AKI and complicated by a rash. CT venogram identified suggestion of a chronically occluded IVC remnant, with contrast present in the native kidneys, which appeared small and unscarred, as well as a thin (2mm) cord extending from the liver to the transplant kidney (See Image 1). Subsequently, she underwent endovascular balloon recanalization of the right common iliac vein and IVC to 14mm with restoration of antegrade flow. Subsequent venogram demonstrated some elastic recoil and collapse of the recanalized IVC, so she underwent dilatation of the IVC to 18mm with iliocaval segment reconstruction with stents (20mm caval stents and 10mm iliac stents) shown in Image 2. Repeat imaging 2 days later demonstrated patent stenting in the common iliac vein and IVC, with persisting dilated azygous system, however the lumbar veins had decreased in calibre. Post stenting, her creatinine was 115µmol/L increasing to 144µmol/L after walking 20,000 steps/day for two consecutive days. Image 1: CT venogram showing chronically occluded IVC remnant (indicated with arrow). Image 2: Angiography showing successful IVC stent placement. ▪▪▪ ▪▪▪ The aim of iliocaval reconstruction was to provide a low resistance pathway for venous drainage which would not be subject to extrinsic compression. Iliocaval reconstruction appears to have improved the effect of exercise on renal function.

03:36 PM Abstract No. 97 The Wallflex colonic stent adapted for endovascular treatment of malignant IVC obstruction

Malignant inferior vena cava (IVC) obstruction may cause debilitating ascites and lower extremity and perineal edema in late stage cancer patients. IVC stent placement can palliate symptoms, but available stents exhibit risk of migration and suboptimal radial strength and sizes. We report our early experience with use of the Wallflex colonic stent adapted for treatment of malignant IVC syndrome. From 2009-2018, self-expanding Wallflex colonic stents (all 25 mm diameter with a 30 mm distal flare; 60, 90, or 120 mm length) were placed in 36 patients (median age 63 yrs) to treat malignant IVC syndrome. Anatomical, procedural, and clinical outcome data were retrospectively evaluated. IVC obstruction was due to primary liver cancer (n = 9) or liver and/or retroperitoneal metastases (n = 27) with mean lesion length of 13.6 cm and baseline pressure gradient of 16.4±5.5 mm Hg (range 6-28). Ten patients had IVC tumor thrombus. Wallflex stents were placed transfemorally in 35 and by jugular vein in 1. The first 3 stents were placed for salvage fixation of Wallstents that had partially migrated into the right atrium. An additional 3 were used to treat recurrent or residual stenosis after Gianturco Z-stent placement. The Wallflex stent was the primary device in the remaining 30. Twelve cases required coaxial placement of Palmaz XL stents for additional radial strength. Technical success was 100% with pressure gradient reduction to 3.7±3.0 mm Hg (range 0-12, p<0.001). Post-stenting anticoagulation was given for 14 patients. In short-term follow-up, leg edema and/or ascites improved in 34 (94.4%) patients, unchanged in 2, unknown in 1. Acute IVC thrombosis occurred in 1 patient with extensive intraluminal tumor thrombus. Cranial stent migration was not seen intraprocedurally. In the one patient with transjugular stent placement, asymptomatic partial migration of the Wallflex stent into the right atrium was incidentally found on CT 38 days later. The Wallflex colonic stent is an attractive option adaptable for use in the palliative treatment of malignant IVC syndrome. Transfemoral stent placement is recommended. Reinforcement with balloon expandable stents may be necessary.

Outcomes of Stent Placement for Chronic Occlusion of a Filter-bearing Inferior Vena Cava in Patients with Severe Post-thrombotic Syndrome

To evaluate the technical aspects and short-term clinical results of stent placement for chronic occlusion of a filter-bearing inferior vena cava (IVC) in patients with severe post-thrombotic syndrome (PTS). A retrospective analysis of 24 patients with severe PTS associated with occlusion of a filter-bearing IVC treated by stent placement was conducted at a single institution from January 2010 to December 2014. Patient-reported quality of life and limb Villalta scores were evaluated before and after treatment by questionnaire and clinical examination, respectively. Stent patency was evaluated by duplex Doppler ultrasound, venography, or venous computed tomographic (CT) angiography. All patients tolerated the procedure well. Nineteen patients with filter-bearing IVC and bilateral iliofemoral occlusions were treated with "double-barrel" stents, two were treated with fenestrated stents, and the remaining three patients were treated by unilateral stent placement of the iliofemoral vein and filter-bearing IVC. Quality of life and Villalta scores were significantly improved (p<.001) after the procedure. The 1-year, and 2-year cumulative primary and secondary stent patency rates were 67% and 91%, and 45% and 77%, respectively. During a median follow-up period of 27 months (range 3-55 months), the cumulative rates of complete relief of pain (visual analog scale >5) and swelling (grade 3) were 77% (13 of 17 limbs at risk) and 75% (24 of 32 limbs at risk), respectively. There were 23 limbs with active ulcers and the cumulative rate of ulcer healing at 2 years was 73%. There were no cases of clinical bleeding, symptomatic pulmonary embolism, or mortality. Recanalization of an occluded IVC filter and stent placement through the filter is a feasible and safe method for management of PTS associated with filter-bearing IVC occlusions, with acceptable short-term stent patency and clinical results. However, close follow-up after procedure is necessary because of a relatively high re-occlusion rate.

Technical and Anatomic Factors Influencing the Success of Inferior Vena Caval Stent Placement for Malignant Obstruction

PurposeTo evaluate the outcomes of inferior vena cava (IVC) stent placement for malignant obstruction and to identify anatomic and procedural factors influencing technical and clinical success. Materials and MethodsA total of 57 patients (37 male, 20 female; age range, 22–86 y) underwent 62 IVC stent placement procedures using 97 stents (47 Wallstents, 15 S.M.A.R.T. stents, 18 Wallflex stents, 17 others) from 2005 to 2016 for malignant IVC obstruction caused by hepatic metastases (n = 22; 39%), primary hepatic malignancy (n = 16; 28%), retroperitoneal metastases (n = 16; 28%), or other primary malignancy (n = 5; 9%). Presenting symptoms included lower-extremity edema (n = 54; 95%), ascites (n = 28; 50%), and perineal edema (n = 14; 25%). Sixteen percent (n = 10) and 10% (n = 6) of the procedures involved tumor and bland thrombus, respectively. ResultsStent placements resulted in 100% venographic patency and significantly decreased pressure gradients (P < .0001). Lower-extremity swelling, perineal swelling, and abdominal distension improved within 7 days in 83% (35 of 42), 100% (9 of 9), and 40% (6 of 15) of patients, respectively, and at 30 days after the procedure in 86% (25 of 29), 89% (8 of 9), and 80% (4 of 5) of patients, respectively. Increased pre- and post–stent placement pressure gradients were associated with worse outcomes. A 4% stent misplacement rate (4 of 97) was related to the use of Wallstents with caudal stent tapering, asymmetric deployment superior to the obstruction, suprahepatic IVC involvement, and decreased stent adherence to the IVC wall as a result of local mechanical factors. ConclusionsStent placement is reliable, rapid, and durable in improving malignant IVC syndrome. Understanding of technical and anatomic factors can improve accuracy and avoid complications of stent misplacement.

Technical considerations, outcomes, and durability of inferior vena cava stenting.

Inferior vena cava (IVC) thrombosis is an uncommon condition but can cause devastating complications to those affected. Historically, this has been treated with an open surgical approach (with high morbidity) and with angioplasty in more recent years. Herein we describe technical aspects of stenting of the IVC in patients with recalcitrant chronic occlusive disease and evaluate its outcomes. We reviewed all the patients treated in an endovascular fashion for venous disease at our institution from 2005 to 2014 to identify and to include those with IVC stent placement in this study. Clinical characteristics, treatment details, and outcomes data were collected from medical records. Primary end points were technical success, symptom resolution, freedom from reintervention, and patency rate at follow-up. Twenty-eight patients (15 men) with a mean age of 48 ± 2.7 years underwent IVC stent placement for 16 occlusions (4 congenital) and 12 high-grade stenoses. Hypercoagulable state was noted in 14 patients, 7 of whom had malignant disease. A previously placed IVC filter was present in 13 patients. Median time from onset of symptoms to presentation was 81 months (3-480 months). Lytic therapy with tissue plasminogen activator (Alteplase) was performed in 12 patients for a median of 2 days (range, 1-3 days). Self-expanding stents (Wallstent; Boston Scientific, Natick, Mass) were used most commonly in the IVC (n = 22) with or without adjunctive use of balloon-expandable stents (Palmaz stent; Cordis, New Brunswick, NJ). Technical success was 100%. At median follow-up of 10 months (range, 0-56 months), thrombotic complications requiring reintervention occurred in four patients at 1, 4, 8, and 37 months. One patient died at 2 weeks secondary to underlying malignant disease. Freedom from reintervention, patency rate, and symptom-free survival rate at 2 years were 84%, 90%, and 80%. Endovascular stenting for chronic occlusive disease of the IVC is safe and effective in the midterm follow-up, with minimal morbidity. Reintervention rate is low, with excellent functional outcomes.

Long-term efficacy of stent placement for treating inferior vena cava stenosis following liver transplantation

The aims of this study were to evaluate both the efficacy of stent placement for treating inferior vena cava (IVC) stenosis and the patency of hepatic veins (HVs) following IVC stent placement. Fourteen hepatic transplant recipients underwent stent placement to treat IVC stenosis. The median interval between transplantation and stent placement was 32 days. Stents varied from 20-36 mm in diameter and were 60-120 mm long. We retrospectively analyzed the technical and clinical success, changes of hepatic venous flow, and the patency of the IVC stents. Stent placement was successful in all patients. Clinical success was achieved in 12 patients. Four patients underwent HV balloon angioplasty or stent placement through IVC stent meshes either immediately (n = 1) or 12-110 days after (n = 3) IVC stent placement. Nine of the 12 patients were healthy when this manuscript was completed, and the last follow-up computed tomography scan obtained at a median of 65.3 months after IVC stent placement revealed the patency of the stent-placed IVC and HVs. IVC stent placement seems to be an effective treatment with an excellent, long-term patency for treating posttransplant stenosis, although the possibility of hepatic venous outflow abnormalities following IVC stent placement should also be considered.

Intravascular Ultrasound–guided Direct Intrahepatic Portacaval Shunt: Midterm Follow-up

To describe the midterm patency and clinical results of the intravascular ultrasound (US)-guided direct intrahepatic portacaval shunt (DIPS) procedure for the treatment of intractable ascites and variceal bleeding. From February 23, 1999, to December 18, 2002, inferior vena cava (IVC)-to-portal vein (PV) shunts were created in 40 patients for ascites (n = 35) and bleeding (n = 5). Intravascular US was used to guide direct puncture from the IVC to the PV. The shunts were completed with the use of single (n = 15) or overlapping (n = 25) polytetrafluoroethylene (PTFE)-covered Palmaz stents. These stent-grafts were deployed primarily at diameters of 8 mm. The diameter of the shunt was increased in three cases to achieve a target portosystemic gradient (PSG) of 15 mm Hg or lower. All patients were followed clinically and with portography with manometry. All DIPSs were created successfully. Mean PSGs were reduced from 23 mm Hg before DIPS creation to 9 mm afterward. During the follow-up period of a maximum of 38 months, 22 of 40 patients died or underwent liver transplantation (mean follow-up, 9 months; median, 6 months). At the time of this report, 18 of 40 patients remain living after follow-up ranging in duration from 8 to 38 months (mean, 22 months; median, 16.5 months). During the follow-up period, there was one stent-graft occlusion and three stenoses. These four patients were successfully treated by additional stent-graft placement. In addition, two patients developed IVC stenosis cephalad to the DIPS, which required IVC stent placement. The primary patency rates by Kaplan-Meier analysis were 100% at 6 months and 75% (95% CI, 53%-97%) at 12 months. Intravascular US-guided direct IVC-to-PV shunts may be created successfully with minimal complications. Primary patency of the shunt is greater than that with conventional TIPS with a bare wire stent and appears equal to that with TIPS with a PTFE-covered stent-graft.

Clinical outcome after intrahepatic venous stent placement for malignant inferior vena cava syndrome.

We evaluated the clinical outcome of malignant inferior vena cava (IVC) syndrome after intrahepatic IVC stent placement by retrospective analysis of 50 consecutive patients (25 men, 25 women, age 32-83 years) with malignant IVC syndrome who were treated with intrahepatic stent placement. Gianturco-Rosch-Z (GRZ) stents (n = 45), and Wallstents (n = 5) were inserted. Clinical outcome was assessed from patients' records using a score based on leg swelling, scrotal/vulvar edema, ascites and anasarca before and after stent placement, as well as at last follow-up visit before death. Clinical follow-up was supplemented by duplex sonography in 36 patients. Inferior venocavography was performed in 5 patients prior to re- intervention. Follow-up time ranged from 1 to 932 days (mean 62 days). Mean pressure gradient in the IVC was reduced from 14 +/- 4.1 mmHg before to 2.9 +/- 3.2 mmHg after stent placement (p < 0.001). Four patients had stent occlusion, 2 of whom were successfully re-stented. Primary and secondary patency was 59% and 100%, respectively at 540 days. Immediate clinical data were available in 44 patients: 38 improved; 6 did not respond. Last follow-up visit data were available in 36 patients: 24 showed persistent symptom relief till death. All symptom scores were significantly improved after stent placement (p < 0.001) and with the exception of ascites, remained significantly improved (p < 0.05) until the last follow-up. Increased serum bilirubin was a common characteristic of clinical failures and recurrences. Intrahepatic IVC stent placement resulted in significant symptomatic relief in patients with malignant IVC syndrome. Palliation was effective even in patients with a very short life expectancy.

Ultrasonically Guided Inferior Vena Cava Stent Placement: Experience in 83 Cases

Traditionally, inferior vena cava (IVC) stent placement is performed with fluoroscopic guidance. The object of this study was to evaluate use of ultrasound (US) as guidance for IVC stent placement for the management of Budd-Chiari syndrome. Eighty-three patients with IVC membranous stenosis (n = 30), membranous occlusion (n = 19), segmental stenosis (n = 21), or segmental occlusion (n = 13) underwent IVC recanalization, balloon dilation, and stent placement under US guidance. Among the 83 patients, 67 had at least one patent hepatic vein, while 16 patients had three occluded hepatic veins. IVC stents were successfully placed in 79 of 83 patients, with a success rate of 95%. After the procedure, the symptoms and signs of IVC obstruction disappeared or markedly improved in all patients, and the blockage of hepatic outflow was alleviated in 67 patients. Pericardial effusion, complete atrial ventricular block, and stent migration into the right atrium occurred, respectively, in one patient. During 1-46-month follow-up, stent restenosis occurred in one patient; the other stents remained open and functioned effectively. Because of the absence of nonionizing radiation and iodinated contrast material, and its low cost, US is well suited and often preferred for guidance of IVC stent placement.