Inferior Vena Cava Stent Research Articles

Complications of Deep Venous Stenting and Their Management.

Complications after iliofemoral and inferior vena cava stenting are rare, and most can be managed effectively without significant long-term consequences for the patient. Nevertheless, the procedure is not without risk, and clinicians considering starting a venous practice must be aware of the range of complications that can occur, which range from minor access site bleeds to fatal arrhythmia from stent migration to the heart. Most complications can be avoided with appropriate patient selection, stent sizing, and careful access and deployment techniques.

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.

Abstract 18056: Transhepatic and Trans-Patent Foramen Ovale Ablation of Atrial Fibrillation in the Setting of Chronic Inferior Vena Cava Occlusion: Addressing Complex Anatomic Hurdles and Achieving Therapeutic Success

Background: Rhythm control for atrial fibrillation (AF) is the preferred approach for symptomatic patients, particularly those with reduced ejection fraction. Catheter ablation primarily consists of pulmonary vein isolation via a transseptal approach. In patients with chronic occlusion of inferior vena cava (IVC), surgical ligation of IVC, or congenital venous system abnormalities, conventional femoral venous access may not feasible. Case Report: A 78-year-old male with history of Hypertension, diabetes, coronary artery disease, bilateral DVTs s/p thrombectomy, prior IVC stenting, presented with persistent, symptomatic AF on apixaban. Given a moderately reduced EF of 40-45%, amiodarone intolerance, and contraindication to other AADs, he was referred for catheter ablation. CT venogram showed chronically occluded IVC with patent hepatic veins, therefore transhepatic access to the right atrium was obtained. Transesophageal echocardiography (TEE) was planned for transseptal puncture; however, this showed an incidental PFO. This PFO was easily engaged using a manual modification of a VersaCross transseptal sheath and after entering the left atrium, the sheath was exchanged with a bi-directional sheath (Vizigo). Using this single left atrial access, pulmonary vein isolation and posterior wall isolation were performed. The transhepatic access site was closed with coil embolization to prevent track bleeding (figure 1). Conclusion: We present a case where successful AF ablation was achieved via percutaneous transhepatic approach, with improvised utilization of a conveniently located PFO. This was guided by pre-operative CT, and intra-operative TEE which allowed us to minimize any transseptal puncture related complications. The utilization of a multidisciplinary team comprising electrophysiologists, advanced imaging cardiologists and interventional radiologists is invaluable in executing complex procedures of this nature.

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.

P02] Inferior Vena Cava Reconstruction: A Single Centre Experience

<h3>Objective</h3> Inferior vena cava (IVC) stenting is carried out for symptomatic chronic IVC stenosis or occlusion, and for the treatment of malignant IVC obstruction. The patency of IVC stents placed for both acute on chronic and chronic venous occlusion was determined. <h3>Methods</h3> Retrospective analysis of prospectively collected data was completed on all patients who underwent technically successful IVC stenting for treatment of symptomatic venous outflow obstruction or stenosis between February 2015 and November 2021. All patients had standard pre-operative work up, including venography ± intravascular ultrasound for chronic cases, and followed standard anticoagulation and surveillance programmes post-procedure, unless there was malignant disease. <h3>Results</h3> Sixteen patients underwent IVC stenting. Seven cases (43%) presented acutely with deep vein thrombosis and chronic underlying IVC stenosis or occlusion. Five cases (31%) were for symptomatic malignant external IVC compression. In four cases (25%), kissing iliac stents were placed into the IVC to treat infrarenal IVC disease. The remainder required single stents in the IVC, or were combined with double barrelled iliac stents. Re-intervention occurred in four cases (25%) for in stent thrombosis. Primary patency was 75%, and primary assisted patency was 88%. Stenting the IVC in all cases for malignant obstruction gave symptomatic relief. <h3>Conclusion</h3> Stenting of the occluded/atretic IVC may require additional access from the right internal jugular vein. Stenting above and across the renal veins did not cause any additional complications in this series. Stenting of the IVC is safe, and can give significant improvement in symptoms in patients with limited alternative options for treatment.

RARE CASE OF MASSIVE DVT AFTER MRNA COVID-19 VACCINATION IN A PATIENT WITH CONGENITAL IVC ANOMALY

RARE CASE OF MASSIVE DVT AFTER MRNA COVID-19 VACCINATION IN A PATIENT WITH CONGENITAL IVC ANOMALY

Simultaneous IVC/SVC Endovascular Sharp Recanalization in A Patient with Budd-Chiari Syndrome, Systemic Lupus Erythematosus and Antiphospholipid Syndrome, A Case Report

Abstract:&#x0D; Background: Budd‐Chiari syndrome (BCS) is a rare life-threatening condition and is caused by an obstruction to the hepatic venous outflow. We herein report a case of BCS complicated with inferior vena cava (IVC) and superior vena cava (SVC) stenosis that was managed by a simultaneous IVC/SVC sharp recanalization.&#x0D; Case presentation: A forty-year-old lady came to the clinic complaining of distended abdomen. She is a known case of antiphospholipid syndrome and systemic lupus erythematosus. Triphasic liver computed tomography showed a heterogeneous liver with nutmeg appearance and attenuation of hepatic veins with caudate hypertrophy. There was a severe dilatation of the azygos and hemiazygos veins with multiple posterior mediastinal and retrocrural tortuous collaterals recanalizing the IVC distally. Contrast enhanced CT of the chest showed a chronic complete occlusion of the left brachiocephalic vein with enlargement of the left superior intercostal vein, hemiazygos, and azygos veins. SVC was patent with multiple calcific foci of the wall likely related to chronic thrombosis. Through the right femoral access, inferior venacavogram was obtained, which showed suprahepatic IVC complete occlusion. Then, an upper venous access was obtained through the right internal jugular vein. Followed by a venogram which showed a complete occlusion at the right brachiocephalic vein with extensive collaterals were noted. Sharp recanalization from the jugular access of the brachiocephalic vein/SVC was performed targeting the balloon within the SVC that was advanced from the azygos vein, which followed by placing a covered stent graft. Then Multiple balloon angioplasties were made at the level of suprahepatic IVC followed by placing a non-covered stent.&#x0D; Conclusion: It was a Successful recanalization for the completely occluded suprahepatic IVC and placement of IVC stent, and a Successful recanalization for the completely occluded right brachiocephalic vein and placement of a stent.

Cuffed endotracheal tube as a cardiopulmonary bypass venous return cannula.

Cuffed endotracheal tube as a cardiopulmonary bypass venous return cannula.

Surgical and reconstructive outcomes in primary venous leiomyosarcoma

ObjectivePrimary venous leiomyosarcomas (PVL) are rare and pose challenges in surgical management. This study evaluates the clinical outcomes and identifies predictors of survival in our surgical series of PVL. MethodsA retrospective review was performed of patients who had resection of PVL at three centers between 1990 and 2018. Patient demographics, comorbidities, intraoperative data, survival, and graft-related outcomes were recorded. Survival analysis was performed using Kaplan-Meier curves and Cox proportional hazards regression. ResultsSeventy patients with a diagnosis of PVL were identified between 1990 and 2018. Fifty-four patients (77%) had PVL of the inferior vena cava (IVC) and 16 (23%) had peripheral PVL. The mean follow-up for the series was 55.0 months (range, 1-217 months). Fifty-one patients (96%) with IVC-PVL needed caval reconstruction and 3 (4%) had resection only. There were no deaths within 30 days of surgery. Five patients (9%) required early reintervention including one (2%) IVC stent. Sixteen peripheral PVL were identified. Eight patients (50%) had venous reconstructions performed and 8 (50%) had the vein resected without reconstruction. There were no deaths within 30 days. Five-year survival was 57.5% for IVC-PVL and 70.0% for peripheral PVL. Kaplan-Meier survival analysis for IVC and peripheral PVL revealed no difference in overall survival (P = .624) at 5 years. ConclusionsPVL is a rare and aggressive disease even with surgical resection. We found no difference in survival between IVC and peripheral lesions, suggesting that aggressive management is warranted for PVL of any origin. Management of PVL requires a multidisciplinary approach to provide patients with the best long-term outcomes.

Budd-Chiari syndrome: consensus guidance of the Asian Pacific Association for the study of the liver (APASL).

Budd Chiari syndrome (BCS) is a diverse disease with regard to the site of obstruction, the predisposing thrombophilic disorders and clinical presentation across the Asia-Pacific region. The hepatic vein ostial stenosis and short segment thrombosis are common in some parts of Asia-Pacific region, while membranous obstruction of the vena cava is common in some and complete thrombosis of hepatic veins in others. Prevalence of myeloproliferative neoplasms and other thrombophilic disorders in BCS varies from region to region and with different sites of obstruction. This heterogeneity also raises several issues and dilemmas in evaluation and approach to management of a patient with BCS. The opportunity to recanalize hepatic vein in patients with hepatic vein ostial stenosis or inferior vena cava stenting or pasty among those membranous obstruction of the vena cava is a unique opportunity in the Asia-Pacific region to restore hepatic outflow closely mimicking physiology. In order to address these issues arising out of the diversity as well as the unique features in the region, the Asia Pacific Association for Study of Liver has formulated these guidelines for clinicians.

Abstract No. 504 Update: iliocaval-in-stent restenosis

To examine patient, stent, and angioplasty factors associated with 50% and 75% in-stent restenosis (ISR) of iliocaval stents placed for chronic venous thrombosis with results at 1, 3, 5, and 20 years post-placement. All patients with symptomatic chronic iliocaval venous thrombosis who underwent iliocaval stent placement with either SMART (Cordis, Santa Clara, CA) or Wallstent (Boston Scientific, Natick MA) at an academic medical center from 1996 to 2018 were compiled from a departmental database. In total, 620 iliocaval stents (430 SMART, 190 Wallstent) were placed in 176 patients (52.8% male, median age 51.1 y). Median follow -was 538.1 days (range, 0–6473 days). Rates of ISR at > 50% and > 75% luminal obstruction were calculated using Kaplan-Meier methods. Cox regression analysis of the effects of age, gender, stent brand, stent diameter, stent length, and angioplasty balloon diameter, on ISR was performed. Median and mean time to ISR were 153.5 and 299.2 days, respectively (range, 3–3985 days). In the 20 year follow-up period, ISR occurred in 8.7% of inferior vena cava (IVC) stents, 10.9% of common iliac vein (CIV) stents, and 15.3% of external iliac vein (EIV) stents. Gender did not affect ISR. Increased age was associated with a small but significant increased risk of ISR when all veins were examined as a single cohort at 1, 3, 5, and 20 years and within the EIV at 3, 5, and 20 years. Wallstents were associated with decreased rate of ISR when all veins were examined as a single cohort at 1, 3, 5, and 20 years as well as within EIV and CIV at 1, 3, 5, and 20 years. A small but significant increased risk of ISR was noted with larger stents in the EIV at 1, 3, 5, and 20 years and IVC at 1 year only as well as when all veins are examined as a single cohort at 1, 3, 5, and 20 years. Smaller balloon diameter demonstrated an increased risk of ISR within IVC stents at 1 year only. When the threshold for ISR was raised to > 75% ISR, all of the above significant results were the same. However, in addition, increasing stent length was associated with a small but significant risk of ISR > 75% when all veins were examined as a single cohort at 1, 3, 5, and 20 years. Our study demonstrates clinically acceptable and decreased rates of ISR compared to prior studies for the IVC, CIV, and EIV stents. Age is a small but significant risk factor for ISR, especially within the EIV. Wallstents may decrease ISR in iliac veins but are similar to SMART stents when placed in the IVC. Larger balloon diameters may help with short-term IVC ISR and larger stents may increase the risk of ISR in the EIV.

Endovascular management of portal steal syndrome due to portosystemic shunts after living donor liver transplantation.

Background and AimAfter liver transplant, pre‐existent porto‐systemic shunts (PSS) may persist, causing “portal steal,” leading to graft dysfunction, hepatic encephalopathy (HE), and eventual rejection. In recipients of small‐for‐size transplant liver grafts, shunts may be created intraoperatively, facilitating diversion of portal flow to systemic circulation to avoid ill‐effects of portal overperfusion. These iatrogenic shunts may also subsequently lead to portal steal. We aim to evaluate safety and efficacy of endovascular techniques in management of portal steal due to PSSs in living donor liver transplantation (LDLT) recipients.MethodsBetween 2013 and 2020, we encountered five LDLT recipients with large PSS, who presented with graft dysfunction and/or HE. One patient had a surgically created shunt and four had spontaneous shunts, not surgically ligated during transplant. Endovascular techniques including plug‐assisted or balloon‐occluded retrograde transvenous obliteration (PARTO/BRTO) or covered inferior vena cava (IVC) stent grafts were to occlude these PSS and counter the portal steal in all patients. Technical success and clinical outcomes at 1‐year‐follow‐up were assessed.ResultsImaging showed large PSS causing portal steal syndrome in all five patients. IVC stent graft was used to isolate the shunt in two patients and PARTO/BARTO was performed in three patients. One patient had guarded prognosis due to multiple organ dysfunction and died 5 days after endovascular procedure. At 1‐year follow up, graft functions normalized in four patients with no recurrence of HE. No procedure‐related complications were seen.ConclusionEndovascular techniques can be safely and effectively used to counter portal steal syndrome in LDLT recipients, thus avoiding surgical re‐exploration in these patients.

Liver transplantation with suprahepatic caval anastomosis including inferior vena cava stent

Budd Chiari syndrome (BCS) results from hepatic outflow obstruction. Endovascular management to restore venous patency, including inferior vena cava (IVC) angioplasty with stenting, and transjugular intrahepatic shunt (TIPS) placement to decompress liver congestion, have become standard of care. Herein, we describe a patient with BCS requiring liver transplantation and the surgical technique of suprahepatic IVC anastomosis including thoracic extension of an IVC stent with a review of the relevant literature. A 29-year-old female with BCS due to polycythemia vera, who had been previously managed with TIPS and IVC stent placement, was taken for liver transplantation. Preoperative imaging confirmed stent extension into the thoracic IVC and the stent was unable to be removed intraoperatively. The thoracic IVC was clamped through the diaphragm at the level of the right atrium and the stent was left in place and incorporated within the suprahepatic anastomosis with good vascular outcome at one year follow up. Diligent preoperative preparation is essential with adequate imaging and cardiac surgical consultation in patients with malpositioned stents. Review of the literature shows four cases in which performing the suprahepatic anastomosis including an embedded stent is a viable alternative that allows for avoidance of a thoracotomy.

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.

3:36 PM Abstract No. 86 Predictors of iliocaval in-stent restenosis

Chronic venous disease (CVD) occurs in 1-5% of adults. Iliocaval obstructive lesions play a significant role in the development of CVD. Iliocaval stenting is a mainstay treatment for CVD. However, in-stent restenosis (ISR) occurs in 5-23% and is related to recurrence of symptoms and possible decreased patency. We sought to evaluate risk factors associated with ISR. Patients who underwent successful iliocaval stenting were compiled from a departmental database of all lower extremity venous stents from 1996-2018. In total, 760 iliocaval stents were placed in 160 patients (47.5% female, 52.5% male), mean age 48.7 years. Median follow-up was 332 days (range, 0-5627 days). ISR was defined as >50% reduction in luminal diameter. Risk factors examined for ISR included age, gender, type of stent (Wallstent, Boston Scientific, Natick MA) vs. SMART stent (Cordis, Santa Clara, CA), diameter and length of stent, and diameter of angioplasty balloon. Veins included were the inferior vena cava (IVC), bilateral common iliac veins (CIV), and bilateral external iliac veins (EIV). Median and mean time to ISR was 177 and 422 days respectively (range, 11-3985 days). Neither age nor gender were significantly associated with ISR. Location of stent was not associated with increased risk of ISR. ISR occurred in 15.1% of IVC stents, 15.2% of CIV stents, and 18.4% of EIV stents. In both the CIV and EIV, Wallstents had a decreased risk of restenosis when compared to SMART stents (CIV: HR -3.0, P <0.005; EIV: HR -2.4, P = 0.02). Stent brand was not a risk factor for IVC ISR. Angioplasty balloon diameter following stent deployment was a significant risk factor for ISR as increased balloon diameter was associated with a decreased risk of IVC ISR (HR -2.7, P = 0.01). Balloon diameter did not affect ISR for CIV or EIV stents. Our study had clinically acceptable and similar rates of ISR for the IVC, CIV and EIV. Wallstents may decrease ISR in iliac veins but are similar to SMART stents when placed in the IVC. Some literature suggests that over dilation of stents may help long-term patency (4); however, we found that use of larger balloons decrease ISR in IVC stents only.

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.

Abstract No. 592 Two steps forward, one step back: development of contralateral DVT following left common iliac vein stenting

Treatment of iliac vein narrowing/thrombosis necessitates stent deployment which typically extends into the inferior vena cava (IVC). The purpose of this study is to determine whether stent placement into the left iliac vein leads to future contralateral deep vein thrombosis (DVT). A retrospective analysis of 93 consecutive patients that underwent left common iliac vein stent placement between July 2008 and August 2017 was performed. In addition to demographic data the following was collected: proximal and distal stent landing zones, quantification of stent extension into the IVC, etiology of vein stenosis/thrombosis, presence of an IVC filter, incidence of ipsilateral and contralateral DVT, anticoagulation status, risk factors for DVT after stent placement, and reintervention rates. Pre procedural and post-procedure clinic visits were performed on all patients that had a stent deployed. A multiple logistic regression model was used for analysis. 93 patients (67 female, 26 male) underwent stent placement for left common iliac vein stenosis/thrombosis with an average follow-up of 826 days. Contralateral DVT developed in 9/93 (9.68%) with 8/9 developing after 30 days and 1/9 less than 30 days. Clinical symptoms necessitated reintervention on the ipsilateral side in 30/93 (32.29%) patients with 19/30 after 30 days and 11/30 within 30 days. Stent extension into the inferior vena cava was 24.3 ± 13.6 mm. Stent extension into the IVC in patients that developed contralateral DVT was 26.7 ± 18.0 mm. Mean stent diameter placed into the left common iliac vein was 14 mm for all patients. The upper landing zone/ extent of stent extension into the IVC did not carry an association with contralateral DVT formation (p=0.17) or rate of ipsilateral reintervention (p=0.07). Presence of an IVC filter (p=0.22) and stent diameter (p=0.13) did not correlate with contralateral DVT development. Contralateral DVT formation was a frequent finding in this study population but did not reach statistical significance. Further studies are warranted to elucidate potential etiologies for contralateral DVT formation in this patient population.

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.