Venous recanalization by metallic stents after failure of balloon angioplasty or surgery: four-year experience

Indications, technical aspects, and outcomes of stent placement in chronic iliofemoral venous obstruction

BACKGROUND

Iliofemoral Venous Stent Placement (IVS) has evolved to a well-established endovascular treatment modality for chronic iliofemoral venous obstruction (CIVO). Dedicated venous stents gained FDA approval in 2019 and solidified IVS as a defined intervention with clear indications, contraindications, risks, benefits, and procedural management principles. This review focuses on the indications, technical aspects and outcomes of stenting for CIVO. Other aspects pertaining to IVS are covered in manuscripts that are part of this series.

METHODS

This study conducted a literature search limited to English articles. Three search strategies were employed, and references were managed in Covidence software. Four investigators independently screened and evaluated articles, excluding meta-analyses, clinical trial protocols, and non-relevant studies. Eligible studies, focused on clinical outcomes and stent patencies, underwent thorough review.

RESULTS

The literature search yielded 1,704 studies, with 147 meeting eligibility criteria after screening and evaluation. Exclusions were based on duplicates, irrelevant content, and non-iliac vein stent placement.

CONCLUSION

Successful IVS for CIVO relies on meticulous patient selection, consistent use of IVUS during procedures, and attention to the technical details of IVS.

Iliofemoral Vein Stenting in a Patient with Pelvic Metastasis

We report a case of an 81-year-old woman with extensive pelvic lymphadenopathy that caused severe stenosis and occlusion of the right common and external iliac veins and proximal common femoral vein. Pelvic lymphadenopathy resulted from the recurrence of a previous right ovarian epithelial tumor. The patient had severe right lower extremity edema, consistent with severe venous insufficiency. She was treated with high-pressure balloon angioplasty (12-14 mm in diameter) and four self-expanding stents (14-10 mm diameter, 80-40 mm length). The postoperative response was dramatic to a near-complete resolution of the edema. The venous clinical severity scores were 10 and 2 at presentation and 6 months after the follow-up, respectively. Balloon angioplasty and stenting are safe and effective methods for providing symptomatic relief for lower extremity venous insufficiency in patients with extensive and unresectable pelvic masses.

A clinical guide to Deep venous stenting for chronic iliofemoral venous obstruction

INTRODUCTION

An increase in endovenous interventions for deep venous pathologies has been observed. This article aims to provide an overview of the role of venous stenting in the management of chronic conditions affecting the deep venous system of the lower limbs, with a focus on intervention relating to the vena cava and iliofemoral venous segments.

METHOD

An overview of the literature on the minimally invasive venous stenting procedures that are being increasingly used in the management of chronic conditions affecting the deep venous system of the lower limbs.

RESULTS

We discuss key areas of interest to a venous specialist practicing in this area, including diagnostic imaging in chronic deep venous disease, with a focus on the use of intravascular ultrasound in this context; treatment of chronic venous outflow obstruction, including the rationale and structural indications for stenting, current guidance regarding stent placement, and fundamental points to consider during decision-making (endophlebectomy and stenting, stenting across the inguinal ligament, optimal sizing of venous stents, extension of venous stenting to beyond the common femoral vein confluence, the role of thrombolysis useful in chronic venous disease, and arteriovenous fistulae); outcomes and initial reports of stenting; and the future of venous stents.

CONCLUSION

Deep venous stenting has become a key treatment option for chronic (thrombotic or non-thrombotic) obstructive venous disease. Dedicated venous stents and intravascular ultrasound represent important technological advances in the minimally invasive treatment of symptomatic chronic deep venous obstruction, which previously required open surgical reconstruction.

Clinical outcomes and overview of dedicated venous stents for management of chronic iliocaval and femoral deep venous disease

OBJECTIVES

Venous stenting of the lower extremities has grown in popularity and is now considered a key component of the primary treatment strategy for the management of pathologically obstructive or stenotic lesions of the deep venous system. This review aims to provide an overview of the role of venous stenting in the management of chronic conditions affecting the deep venous system of the lower limbs.

METHODS

An overview of venous stents design and current role of stenting procedure in individuals presenting with Chronic Venous Insufficiency (CVI) and presenting the current trials of dedicated venous stenting in management of chronic deep venous lesions. This review provides a focused insight on venous stent design, physical properties and the available dedicated venous stents selected studies with their related patency outcome based on selective literature search of the PubMed database and Cochrane library.

CONCLUSIONS

Dedicated venous stent technology is advancing at a rapid pace alongside the increased undertaking of endovascular deep venous stent reconstruction in the management of iliocaval vein pathologies. The ideal design(s) for venous stents remain unknown, although it is hoped that the presence of new dedicated venous stents in clinical practice will allow the generation of experience and data to advance our understanding in this area.

Iliac vein stenting in a patient with lower extremity swelling resulting from diffuse pelvic mass: A case report

We report a 66-year-old male patient with severe right lower extremity swelling resulting from diffuse pelvic mass with compression on right external iliac vein. The patient had papillary urothelial carcinoma of bladder seven years ago and radical cystectomy and ureterostomy was performed. Recurrence of malignancy had occurred five years after the operation. The patient had also bilateral diffuse lung metastasis. The external iliac vein had severe stenosis and invasion of pelvic mass into the vein was evident on venography. Venoplasty of external iliac vein was performed throughout the stenosis. A venous stent of 80 mm length and 12 mm diameter was introduced over the guidewire and deployed in the external iliac vein. Dramatic clinical response was evident since postoperative day two. Swelling of right lower extremity was resolved dramatically on three-month and six-month follow-up visits. We believe that endovascular venous recanalization of iliac veins is feasible and safe in patients with unresectable and diffuse pelvic masses.

Inferior Vena Cava Reconstruction in Symptomatic Patients Using Palmaz Stents: A Retrospective Single-Center Experience

BACKGROUND

The use of stents for treating central venous occlusion is well described. Limited evidence exists related to Palmaz balloon-expandable stent use in inferior vena cava (IVC) reconstruction. We analyzed patency and complication rates after IVC reconstruction using Palmaz stents.

METHODS

From 2002 to 2019, 37 patients (mean age: 51 year) underwent IVC reconstruction with 68 Palmaz stents. Indications were symptomatic chronic venous obstruction in the infrarenal (n = 25) and intrahepatic (n = 12) IVC. Demographic, operative, and imaging data were evaluated. Clinical data, abdominal CT, and/or duplex ultrasound were used to determine patency at follow-up.

RESULTS

Restoration of caval patency was achieved in all patients, with complications in 2/37 (5.4%) patients (thrombus formation within the stent; stent embolization eight days after placement). Follow-up data were available for 27 patients. Primary patency was maintained through last follow-up in 19/27 (70%) patients (mean: 1.1 year), with successful stent redilation performed in 6 patients. Mean duration of primary-assisted patency (n = 5) was 1.2 year. Late lumen loss was (n = 13) was 40% during a mean time to follow-up of 2.0 years. Primary patency in patients with occlusion secondary to malignancy was 109 day (range: 1 day-1.0 year), whereas primary patency in patients with occlusion from other etiologies was 1.1 year (range: 2 day-5.9 year). The Kaplan-Meier analysis demonstrated primary and primary-assisted patency of 66% and 84%, respectively, at 24 and 48 months.

CONCLUSIONS

Palmaz balloon-expandable stents for IVC reconstruction is feasible and effective for symptomatic IVC occlusion. Risk of stent migration was low.

A systematic review on the use of deep venous stenting for acute venous thrombosis of the lower limb

OBJECTIVES

The aim is to evaluate venous stent patency, the development of post-thrombotic syndrome, recurrence, quality of life and the optimal post-procedural anticoagulation regimen in the treatment of iliofemoral deep venous thrombosis.

METHOD AND RESULTS

EMBASE and Medline databases were interrogated to identify studies in which acute deep venous thrombosis patients were stented. Twenty-seven studies and 542 patients were identified. Primary, assisted primary and secondary patency rates 12 months after stent placement ranged from 74 to 95, 90 to 95 and 84 to 100%, respectively. The observed post-thrombotic syndrome rate was 14.6%. The incidence of stent re-thrombosis was 8%. In 26% of studies, patients received additional antiplatelet therapy. Quality of life questionnaires employed in 11% of studies, demonstrating an improvement in the chronic venous insufficiency questionnaire (22.67 ± 3.01 versus 39.34 ± 6.66).

CONCLUSION

Venous stenting appears to be an effective adjunct to early thrombus removal; however, further studies are needed to identify optimal anticoagulant regimen and effect on quality of life.

Efficacy and patency of primary stenting for hepatic venous outflow obstruction after living donor liver transplantation

BACKGROUND

Hepatic venous outflow is important for graft survival in living donor liver transplantation (LDLT). If hepatic venous outflow obstruction occurs, hepatic vein stenting is considered to restore the patency.

PURPOSE

To retrospectively evaluate the efficacy and patency of primary hepatic vein stenting for hepatic venous outflow obstruction (HVOO) after LDLT.

MATERIAL AND METHODS

Percutaneous interventions, including hepatic vein stent placement with or without balloon angioplasty, were performed in 21 patients who had undergone LDLT and had HVOO confirmed through hepatic venography or manometry, including the patients who had a structural abnormality. Two stents each were inserted in four patients; therefore, the total number of treated anastomoses was 25. Technical success, patency rates, and pressure gradients between hepatic veins and the right atrium were evaluated in 19 patients each.

RESULTS

Technical success was achieved in 25 of 26 vessels (96%). The mean interval between operation and stenting was 43 days. After the procedure, the follow-up period was a mean 530 days. The mean pressure gradient decreased from 8.5 mmHg to 2.1 mmHg after treatment (P < 0.01). The patency rates of the 25 vessels were 80% at 1, 2, and 3 years after stent placement. However, middle hepatic vein stenting revealed a low patency rate (all were 36%). Three of seven stents (43%) in the middle hepatic vein occluded during follow-up.

CONCLUSION

Percutaneous primary hepatic vein stent replacement is an effective treatment for HVOO after LDLT.

Diagnosis and Treatment of Lower Extremity Deep Vein Thrombosis: Korean Practice Guidelines

Lower extremity deep vein thrombosis is a serious medical condition that can result in death or major disability due to pulmonary embolism or post-thrombotic syndrome. Appropriate diagnosis and treatment are required to improve symptoms and salvage the affected limb. Early thrombus clearance rapidly resolves symptoms related to venous obstruction, restores valve function and reduces the incidence of post-thrombotic syndrome. Recently, endovascular treatment has been established as a standard method for early thrombus removal. However, there are a variety of views regarding the indications and procedures among medical institutions and operators. Therefore, we intend to provide evidence-based guidelines for diagnosis and treatment of lower extremity deep vein thrombosis by multidisciplinary consensus. These guidelines are the result of a close collaboration between interventional radiologists and vascular surgeons. The goals of these guidelines are to improve treatment, to serve as a guide to the clinician, and consequently to contribute to public health care.

Use of Cryopreserved Small Aortic Homografts for Large Vein Replacement

Total obstruction, stenosis, or ligation of any large vein is associated with significant morbidity. No synthetic grafts can adequately replace large veins, particularly in areas subjected to motion (flexion or extension). Artificial prosthetic materials usually occlude within a short period.

Since 1987, the author has used cryopreserved allografts of small aortas varying from 1 to 1.7 cm in diameter to replace large vein channels in the upper or lower body. These allografts provide a manageable, pliable conduit with normal endothelium. He implanted grafts bridging gaps from 4 to 30 cm in length, in 14 patients (10 women, 4 men). Veins replaced were five iliac, three iliofemoral, and six subclavian-innominate. The long-term patency rate (follow-up 3 months to 10 years) is 93%.

The use of small aortic cryopreserved homografts for large vein replacement, particularly in mobile areas (groin, thoracic inlet, pelvis) is recommended. These grafts appear superior to any previous grafts used for the same purpose.

Arteriovenous fistula geometry in hybrid recanalisation of post-thrombotic venous obstruction

Introduction

Post-thrombotic obstruction can be adequately treated by percutaneous transluminal angioplasty and stenting. When post-thrombotic trabeculations extend below the femoral confluence, proper inflow can be facilitated by endophlebectomy and creation of an arteriovenous fistula. The aim of this study was to investigate whether it is more favourable to place the arteriovenous fistula at the cranial or caudal end of the endophlebectomy to prevent stenosis or occlusion.

Methodology

We retrospectively analysed the clinical data of all patients who underwent a hybrid procedure in our two centres. Demographics, interventional details and post-operative imaging were collected.

Results

Data on 42 limbs with cranially and 23 limbs with caudally placed arteriovenous fistulas were collected. Post-thrombotic disease of the profunda femoral vein alone or in combination with the femoral vein was observed more often in the cranial group. The caudal group more often received a smaller sized and straight polytetrafluoroethylene fistula, while the cranial group comprised a significantly higher amount of stented segments. Logistic regression showed that only reduced femoral inflow (hazard ratio 2.934 (95%CI, 1.148–7.494)) was a significant predictor of stent stenosis and/or occlusion. Logistic regression for risk of occlusion showed a significant influence of stent-related complications (hazard ratio 4.691 (95%CI, 1.205–18.260)) and a tendency towards influence of arteriovenous fistula geometry in favour of the cranially placed fistula.

Conclusion

Placement of the arteriovenous fistula in the cranial part of the endophlebectomy during hybrid recanalisation may result in a more favourable outcome, yet this tendency was not statistically significant. Moreover, femoral inflow is pivotal in maintaining patency and should thus be adequately assessed pre-operatively.

Preliminary report on a new concept stent prototype designed for venous implant

Venous obstruction at iliocaval level in both forms, primary and secondary, is a significant cause of severe chronic venous insufficiency. A new therapeutic approach to this pathology emerged with the introduction of stenting procedures that proved effective, leading to good long-term results. However, at present, the majority of implanted stents have been designed for arterial implant and this can pose a limit in particular districts. The purpose of this preliminary acute study was to verify the deliverability and safety of a new stent specially designed for venous-vessel implant. We assess the safety and deliverability of two braided, self-expanding, nickel–titanium stents (Jotec GmbH, Hechingen, Germany) specially designed for endovascular implant in veins. The two stents, despite being based on the same concept, have a different design: stent A presents a proximal tapering shape specially designed to reduce migration, while stent B does not. Both of them are enlarged at their distal extremity and present variable radial force the length of the stent itself, the said force becoming very high in the intermediate segment. Stents were implanted in the internal jugular vein of a sheep, showing optimal deliverability. The completion venography showed the migration of stent B into the right atrium. Stent A maintained its location, confirmed by intravascular ultrasound examination. No scaffolding effect was detected and an adequate adherence and adaptability to the vein wall was obtained. In conclusions, the stent A design matches the characteristics required by vein implants. Stability is achieved even where difficult anatomical conditions apply, such as in the jugular vein. Deployment is easy and precise in a given landing zone. Radial resistive force is very high, as required in specific vein districts, but is also associated with good flexibility. Following this preliminary acute report, further studies are required.

Indications for endophlebectomy and/or arteriovenous fistula after stenting

Endovenous recanalization with percutaneous transluminal angioplasty and stenting in post-thrombotic syndrome patients with iliocaval obstruction is a treatment modality quickly gaining popularity. Studies show good patency and clinical success rates. If the obstruction extends distally, below the inguinal ligament, stenting remains controversial. Without adequate inflow, the patency of stented iliocaval segments drops dramatically. This suggests that treatment of diseased common femoral, femoral and profunda femoral veins is required to ensure adequate inflow. Endophlebectomy, the removal of synechiae and septae from the common femoral vein, is a viable option in these cases. Another option, which can be done concurrently with the endophlebectomy, is the creation of an arteriovenous fistula. Selecting patients for these interventions however remains difficult, as precise preoperative prediction of inflow into the stented segments is difficult. In this paper we describe our experience in using duplex ultrasonography, magnetic resonance venography and conventional venography to assess the patency of the inflow trajectory. We believe this approach is essential in dealing with cases of complex post-thrombotic disease extending below the inguinal ligament. There is a great need to establish criteria to accurately assess pre- and postinterventional flow through treated vein segments.

Tratamento endovascular da síndrome de compressão da veia ilíaca (May-Thurner): relato de caso

A Síndrome de May-Thurner é uma causa pouco comum de sinais e sintomas venosos relacionados ao membro inferior esquerdo. Esta síndrome é caracterizada pela compressão da veia ilíaca comum esquerda pela artéria ilíaca comum direita e, quando tal alteração anatômica causa sintomas que venham a prejudicar a qualidade de vida do paciente, existe a indicação de tratamento cirúrgico ou endovascular para correção desta alteração anatômica. Este artigo é o relato de um caso, no qual optou-se pelo tratamento endovascular com resultado satisfatório e as indicações, as nuances e os resultados esperados para esta técnica no tratamento da Síndrome de May-Thurner são discutidos. Foi concluído que, nesta síndrome, há eficácia do tratamento endovascular com melhora dos sintomas pela recanalização do sistema venoso, sem grandes riscos inerentes ao procedimento e com curto período de internação hospitalar.

Deep Vein Thrombosis Associated with May-Thurner Syndrome in an Amyotrophic Lateral Sclerosis Patient -A Case Report-

There have been a few reports on deep vein thrombosis (DVT) associated with compression of the left common iliac vein by the right common iliac artery, referred to as May-Thurner syndrome (MTS). However, there have been no reports on DVT associated with MTS in amyotrophic lateral sclerosis (ALS) patients exhibiting similar clinical features to paraplegic spinal cord injury patients. We hereby report a case of DVT associated with MTS in an ALS patient, who was treated successfully.

Endovascular stenting of ascending lumbar veins for refractory inferior vena cava occlusion

Chronic inferior vena cava (IVC) occlusion is a debilitating disease process. Recently, endovascular techniques have been described using progressive balloon dilatation and stenting to treat IVC occlusion with reasonable success. We present two cases of endovascular dilatation and stenting of the ascending lumbar vein. This technique provided good early relief of symptoms with ulcer healing, decreased swelling, and decreased pain. To our knowledge this is the first report of endovascular therapy of IVC occlusion via stenting of the ascending lumbar vein. This technique may provide a feasible treatment option when the occluded IVC cannot be reopened.

An Experimental Model for the Treatment of Lethal Bleeding Injury to the Juxtahepatic Vena Cava With Stent Graft

BACKGROUND

Juxtahepatic vein injuries present a high mortality rate. Our objectives were to develop an experimental model of endovascular lethal injury of the juxtahepatic inferior vena cava (JHIVC) and to evaluate its hemodynamic alterations; to treat the lesion with volume replacement, and a stent graft (SG); and to follow the animals after treatment.

METHODS

Twenty dogs were anesthetized and monitored [heart rate (HR), mean arterial pressure (MAP), vesical and peritoneal pressures], and submitted to a JHIVC endovascular injury. After volume replacement the dogs were divided into two groups: control (GI) and experimental (GII). GI was observed until death. GII was treated with SG and followed by Doppler ultrasound (DUS) and cavography for 4 (GIIA), and 8 weeks (GIIB), and then sacrificed and IVC and SG were analyzed.

RESULTS

GI presented increased abdominal pressures, arterial hypotension, and death after 80 minutes. GII had a 100% survival rate till sacrifice, without clinical repercussions. At DUS and cavography all SG were patent, with monophasic pulsatile flow. On US, SG diameters after 2, 4, and 8 weeks did not show differences. On cavography IVC diameters presented no difference between groups GIIA and GIIB throughout the experiment. These data analyzed for the GII as a whole, showed statistically significant differences. Average lumen diameter reduction of SG was 27.43+/-20,00%. Pressure values in the IVC cranially, caudally to the SG, and inside the SG, did not show differences. In the IVC with the SG we observed a thicker neointima layer, and the injury in the media layer was covered with fibroconnective tissue.

CONCLUSIONS

We developed an experimental dog model of endovascular lethal injury of the JHIVC with significant increase in abdominal pressures, and a mortality rate of 100%. The treatment of this lesion with SG resulted in a thickened neointima layer, and a 27% reduction in the JHIVC lumen diameter, without clinical repercussion, and with a 100% survival rate.

Isolated right hepatic vein obstruction after piggyback liver transplantation

The "piggyback" technique for liver transplantation has gained worldwide acceptance. Still, complications such as outflow obstruction have been observed, usually attributable to technical errors such as small-caliber anastomosis of the suprahepatic vena cava, twisting, or kinking. Iatrogenic Budd-Chiari syndrome after piggyback liver transplantation has been reported as a consequence of obstruction involving the entire anastomosis (usually the 3 hepatic veins). Here we describe technical issues, clinical presentation, diagnosis, and treatment of 3 cases in which outflow obstruction affected only the right hepatic vein. In conclusion, all 3 patients developed recurrent ascites requiring angioplasty and/or stent placement across the right hepatic vein to alleviate the symptoms.

Successful Endovascular Treatment of Iliac Vein Compression (May-Thurner) Syndrome in a Pediatric Patient

A 10-year-old boy presented to our clinic with left lower extremity swelling present for 1 year with deterioration of symptoms during the prior month. Laboratory investigation for deep vein thrombosis was negative. Venography and computed tomography scan of the pelvis showed compression of the left common iliac vein by the right common iliac artery. A diagnosis of iliac vein compression syndrome was made. After venography, endovascular treatment was planned. The stenosis did not respond to balloon dilatation and a 12 mm Wallstent was placed with successful outcome. The patient's symptoms improved but did not resolve completely, probably due to a chronically occluded left superficial femoral vein that did not respond to endovascular recanalization. To the best of our knowledge, this is the first case of successful endovascular treatment of iliac vein compression syndrome with stent placement in a pediatric patient.

Treatment of hepatic venous outflow obstruction after piggyback liver transplantation

PURPOSE

To evaluate retrospectively the endovascular management of hepatic venous outflow obstruction after piggyback orthotopic liver transplantation.

MATERIALS AND METHODS

The study was performed with the approval and under the guidelines of the institutional review board and complied with the Health Insurance Portability and Accountability Act. Informed consent from patients was not required by the institutional review board for this retrospective study. From 1995 to 2003, 13 patients (eight male, five female), including 12 adults and one adolescent (age range, 14-67 years; median age, 52 years), underwent endovascular treatment of hepatic venous outflow obstruction after piggyback orthotopic liver transplantation. Patients gave informed consent for all procedures. Eleven patients received whole livers, and two received living-related donor right liver lobes. Four underwent repeat piggyback orthotopic liver transplantation prior to intervention. Primary stent placement was performed in 12 patients. One patient refused primary stent placement and chose venoplasty alone, but required a stent 5 months later. Short balloon-expandable stents (mean diameter, 14.6 mm +/- 1.1 [standard deviation]) were used to minimize jailing of branch vessels and to resist recoil. Pre- and post-procedural pressure gradients were measured. Follow-up included venography, cross-sectional imaging, and laboratory tests. The Wilcoxon signed rank test or the sign test was performed to compare pre- and post-procedural pressure gradients, body weights, and laboratory values.

RESULTS

Technical success (pressure gradient < or = 3 mm Hg) was achieved in 13 of 13 patients, and clinical success, in 12 of 13. Mean pre- and post-procedural pressure gradients were 13.0 mm Hg +/- 1.4 and 0.8 mm Hg +/- 0.3. Mean interval from transplantation to intervention was 348 days +/- 159. Mean follow-up was 678 days (range, 16-2880 days). Technical success did not result in clinical improvement in one patient. Biopsy demonstrated severe hepatic necrosis, likely from prolonged venous congestion, and the patient required repeat transplantation. Only one patient required reintervention for stent migration, and no other complications occurred. No significant restenosis was encountered after stent placement.

CONCLUSION

Hepatic venous outflow obstruction is an uncommon but potentially fatal complication of piggyback orthotopic liver transplantation. Endovascular treatment with balloon-expandable stents is effective, safe, and apparently durable.

Stents in Common Iliac Vein Obstruction with Acute Ipsilateral Deep Venous Thrombosis: Early and Late Results

PURPOSE

To evaluate, by imaging and clinical follow-up, the effectiveness and long-term results of stent placement in cases of common iliac vein obstruction associated with ipsilateral deep vein thrombosis (DVT).

MATERIALS AND METHODS

Retrospective analysis of 22 patients (13 women, nine men; median age, 58 years) with common iliac vein obstruction with ipsilateral DVT was performed for this study. All patients presented with leg edema or pain and were treated with catheter-directed thrombolysis (1,000-2,000 U urokinase per kg body weight per hour; n = 19), aspiration thrombectomy (n = 21), or angioplasty (n = 14) followed by stent placement (n = 22) via an ipsilateral popliteal vein approach (right, n = 2; left, n = 20) under ultrasonographic (US) guidance. Patients were then followed by duplex US, and patency rates were determined by Kaplan-Meier survival analysis.

RESULTS

The mean procedure time was 15 hours (range, 1-23 hours) and the mean urokinase dose was 1,980,000 U (range, 600,000-3,600,000 U) before the implantation of 27 stents. Three patients did not receive urokinase. The technical success rate was 96% (26 of 27 stents) and the clinical success rate was 95% (21 of 22 patients). The causes of common iliac vein obstruction were May-Thurner syndrome (n = 16), pelvic mass (n = 2), and unknown (n = 4). The early complications included upward stent migration in one patient and a spinal epidural hematoma in another. The late complication was partial stent obstruction, which was successfully treated by thrombolysis and angioplasty in one patient. Follow-up lasted 1-41 months (mean, 21.4 months). Overall, the 1-year and 2-year primary patency rates were both 95% and the 1-year and 2-year secondary patency rates were both 100%.

CONCLUSION

Directed catheter thrombolysis and aspiration of DVT are relatively safe, and the use of stents improves patency results in cases of common iliac vein obstruction.

[Successful recanulization of superior venous vessels: a new challenge for interventional pediatric cardiology]

The use of long-term central venous catheters is a routine in chronic pediatric diseases. Thrombotic complications progressively reduce the central venous capital and hamper the long-term management of these patients.

OBSERVATION

We report two cases of obstruction of the central upper venous system and discuss of the techniques used to repermeabilize venous axes before the placement of a new central line.

CONCLUSION

The control of the permeability of the central veins should be performed before any withdrawal of central catheters, repermeabilization of the venous axes being simpler when the central catheter is kept in place in the occluded vessel.

Catheter-directed thrombolysis for deep venous thrombosis

Venous thromboembolism (VTE) represents a significant clinical problem, affecting patients of all age groups, nationalities, and socioeconomic strata. Despite its prevalence, the paradigms for care are largely centered around primary or secondary prophylaxis, with less emphasis on actual treatment of the thrombus. With the recent rapid development of advanced endovascular techniques, it is now feasible to dissolve many thrombi using catheter-directed thrombolysis (CDT), and favorable clinical experience has been reported in over 600 patients. If performed safely, the purported benefits of CDT for DVT include a decreased incidence of persistent phlebitic symptoms, improved quality of life and, possibly, a decreased incidence of recurrent thrombotic events.

Clinical and quantitative angiographic outcomes following elective implantation of the self-expanding Wallstent for longer coronary artery lesions--final results of the Wellstent native study

BACKGROUND: Implantation of short balloon-expandable stents provides superior clinical and angiographic outcome compared with balloon angioplasty in selected patients. The purpose of the Wellstent study was to evaluate the safety and efficacy of the self-expanding Wallstent combined with aspirin and ticlopidine in patients with stable or unstable angina related to a native coronary lesion up to 45 mm in length. METHODS: 105 patients (111 lesions) with stable (57%) or unstable (43%) angina were included in this prospective multicentre evaluation. Angiography before and after Wallstent implantation and at 6-month follow-up was analysed at the core lab using the CAAS 2 system. The primary end-point was incidence of major adverse cardiac events (MACE) at 30 days. Secondary end-points were angiographic outcome at 6 months and MACE at 6 months and 1 year. RESULTS: Acute procedural success (successful stent implantation with residual stenosis <20%) was achieved in 99%. Mean reference diameter was 3.18 +/- 0.66 mm, minimal luminal diameter was 1.00 +/- 0.50 mm pre- and 2.84 +/- 0.47 mm poststent (diameter stenosis 16 +/- 6%). The mean hospital stay was 2.2 days. At 30 days, 95% of patients were free of MACE. At 6 month and 1 year clinical follow-up, 75% and 71% of patients, respectively, remained free of MACE, the majority of which (19 of 30) were re-interventions at re-angiography. In 90% of eligible patients, MLD at follow-up was 1.65 +/- 0.75 mm (late loss 1.20 +/- 0.66 mm, loss index 0.66), diameter stenosis 42 +/- 15%, with a restenosis rate of 32%. Longer stents were associated with greater luminal loss (P = 0.001) and less-favourable clinical outcome. CONCLUSIONS: Wallstent implantation, combined with aspirin and ticlopidine, achieved excellent acute and 30 day clinical results in a heterogenous high-risk patient group. Clinical outcome at 6 months and 1 year remained good, and most adverse events were re-PTCA during follow-up angiography. The loss index of 0.66 and restenosis rate of 32%, related in part to the use of longer stents, emphasizes the continuing need for effective anti-proliferative therapy.

Fatal pericardial tamponade after Wallstent implantation for malignant superior vena cava syndrome

PURPOSE

To report a rare, fatal complication of superior vena cava Wallstent implantation.

CASE REPORT

A 59-year-old man presenting with superior vena cava syndrome caused by small-cell lung cancer underwent stent implantation of 2 kissing Wallstents >1.5 cm above the right atrium. Despite correct stent deployment, vessel perforation occurred in a section not encased by tumor, which led to fatal pericardial tamponade shortly after the procedure. Autopsy revealed perforation of a stent strut through the caval wall into the pericardial space. Anatomical and methodological reasons are discussed.

CONCLUSIONS

The interventionist should be aware of this rare complication. Alternative stent designs avoiding the sharp ends of Wallstents and Palmaz stents should be considered.

Endovascular treatment of hepatic venous outflow obstruction after living-donor liver transplantation

PURPOSE

To evaluate the effectiveness and safety of percutaneous interventional management of hepatic venous outflow obstruction after living-donor liver transplantation (LDLT).

MATERIALS AND METHODS

Percutaneous balloon angioplasty (n = 5) and stent placement (n = 22) were attempted in 27 patients with hepatic venous outflow obstruction. Patient follow-up included clinical and laboratory data collection, Doppler ultrasonography (US), hepatic venography, and computed tomography. The following parameters were documented retrospectively: technical success and complications, clinical improvement, and recurrence. Technical success was defined as elimination or successful reduction of pressure gradients across the stenosis and clinical success was defined as amelioration of presenting signs. Recurrence was defined as relapse of clinical signs with hepatic venous anastomotic restenosis on Doppler US.

RESULTS

Technical success was achieved in all patients. The mean pressure gradients across the stenoses before and after the procedure were 10.6 mm Hg +/- 6.4 (range, 3-39 mm Hg) and 2.4 mm Hg +/- 2.6 (range, 0-8 mm Hg), respectively (P < .001). Three of the five patients who underwent balloon angioplasty developed recurrent stenosis 1-5 weeks after the procedure. These patients underwent repeat balloon angioplasty, and two of them eventually underwent stent placement (n = 1) or surgical repositioning (n = 1) of the graft. Three of the 22 patients who underwent stent placement required a second stent placement procedure because of malpositioning, partial migration, and acute angulation. During the mean follow-up period of 49 weeks +/- 47 (range, 3-214 wk), clinical success was achieved in 20 of 27 patients (73%).

CONCLUSION

Percutaneous interventional management is an effective and safe adjunct for the treatment of hepatic venous outflow obstruction after LDLT.

Intravascular ultrasound scan evaluation of the obstructed vein

PURPOSE

The purpose of this study was the comparison of intravascular ultrasound scanning (IVUS) with transfemoral venography in the assessment of chronic iliac vein obstruction.

METHODS

IVUS and standard, single-plane, transfemoral venography were performed in 304 consecutive limbs during balloon dilation and stenting of an obstructed iliac venous segment. The appearance of the obstruction was described, and the degree of stenosis (maximal diameter reduction) was estimated with venography and IVUS. The stenotic area was derived with diameter calculations (pir(2)) and also was measured with the built-in software of the IVUS apparatus before and after dilation and stenting in 173 limbs. Preoperative hand/foot differential pressure and preoperative dorsal foot venous and intraoperative transfemoral hyperemia-induced pressure elevations after intra-arterial injection of papaverine hydrochloride were measured.

RESULTS

With IVUS, fine intraluminal and mural details were detected (eg, trabeculation, frozen valves, mural thickness, and outside compression) that were not seen with venography. The median stenosis (with diameter reduction) on venographic results was 50% (range, 0 to 100%) and on IVUS results was 80% (range, 25% to 100%). In a comparison with IVUS as the standard, venography had poor sensitivity (45%) and negative predictive value (49%) in the detection of a venous area stenosis of >70%. The actual stenotic area was more severe when measured directly with IVUS (0.31 cm(2); range, 0 to 1.68 cm(2)) versus derived (0.36 cm(2); range, 0 to 3.08 cm(2); P <.001), probably as a result of the noncircular lumen geometry of the stenosis. No correlation was found between any of the preoperative or intraoperative pressure measurements and degree of stenosis with or without collaterals. When collaterals were present, a more severe stenosis (median, 85%; range, 25% to 100%) was observed (versus a 70% stenosis in the absence of collaterals; range, 30% to 99%; P <.001), along with actual stenotic area (with collaterals: median, 0.24 cm(2); range, 0 to 1.18 cm(2); without collaterals: median, 0.45 cm(2); range, 0.02 to 1.68 cm(2); P <.01) and a higher rate of hyperemia-induced pressure gradient (> or =2 mm Hg; with collaterals, 34%; without collaterals, 11%; P <.05).

CONCLUSION

Venous IVUS appears to be superior to single-plane venography for the morphologic diagnosis of iliac venous outflow obstruction and is an invaluable assistance in the accurate placement of venous stents after venoplasty. No preoperative or intraoperative pressure test appears to adequately measure the hemodynamic significance of the stenosis. In lieu of adequate hemodynamic tests, IVUS determination of morphologically significant stenosis appears to be presently the best available method for the diagnosis of clinically important chronic iliac vein obstruction. Collateral formation should perhaps be looked on as an indicator of a more severe stenosis, although significant obstruction may exist with no collateral formation.

Proximal lower extremity chronic venous outflow obstruction: recognition and treatment

As postthrombotic disease becomes better understood, the importance of venous outflow obstruction is recognized increasingly. It appears that obstruction of the iliac vein is particularly important and results in more severe symptoms than more distal segmental blockages. Unfortunately, no accurate invasive or noninvasive test for the evaluation of obstruction is available. In fact, it is not known what degree of venous stenosis should be considered hemodynamically "critical." Thus, currently it is impossible to detect borderline obstructions of potential hemodynamic significance. A high index of suspicion must be maintained. The diagnosis relies on clinical signs and symptoms, and treatment must be based on results of morphologic investigations such as transfemoral phlebography or, preferably, intravascular ultrasonography. Percutaneous iliac venous balloon dilation and insertion of a stent offers a safe and efficient method to correct pelvic venous obstruction. It is less invasive and relatively safer than open surgery and can, therefore, be offered to a larger group of patients. Furthermore, initial percutaneous management does not preclude subsequent bypass or reflux surgery. Although the technique is recent and follow-up relatively short, there is cautious optimism that this treatment will be useful and replace bypass surgery for iliac venous obstruction.

Endovascular surgery in the treatment of chronic primary and post-thrombotic iliac vein obstruction

OBJECTIVES

To compare the results and complications of endovascular surgery in limbs with post-thrombotic and non-thrombotic disease and to detail some technical aspects of the procedure.

DESIGN

A single centre, prospective study.

MATERIALS AND METHODS

Between March 1997 and August 1999, 139 consecutive lower extremities with chronic iliac venous obstruction (61 limbs with primary disease [MTS] and 78 with post-thrombotic disease [PTS]) were treated by balloon dilation and stenting. History, clinical examination, procedure and follow-up data were recorded.

RESULTS

Mortality was zero. Non-thrombotic complication rate was only 3%. Postoperative (8%, 6/78) and late occlusion (3%, 2/69) occurred only in post-thrombotic limbs. Primary, primary-assisted and secondary cumulative patency rates of the stented area at 2 years were 52%, 88% and 90%, respectively, in the PTS group as compared to 60%, 100% and 100% in the MTS group. Clinical improvement in pain and swelling was significant in both groups. Half of active venous ulcers healed after the procedure.

CONCLUSIONS

Chronic iliac vein obstruction appears to be a symptomatic lesion that can be treated safely and effectively by endovascular surgery regardless of aetiology. Generous use of IVUS is suggested in both diagnosis and treatment since phlebography is unreliable. The clinical improvement was significant in both groups; however, more excessive neointimal hyperplasia and a higher early and late occlusion rate were observed in post-thrombotic disease. Stenting after balloon dilation is advised in all venoplasties; stents should be inserted well into the IVC when treating iliocaval junction stenosis. A wide-diameter (16 mm) stent is recommended. The stent should cover the entire lesion as outlined by the IVUS.

Balloon dilation and stenting of chronic iliac vein obstruction: technical aspects and early clinical outcome

PURPOSE

To describe the technical aspects of percutaneous balloon dilation and stenting for the treatment of venous outflow obstruction in chronic venous insufficiency.

METHODS

Between March 1997 and December 1998, 94 consecutive patients (median age 48 years, range 14 to 80) with suspected iliac vein obstruction in 102 limbs were studied prospectively with the intent to treat any venous occlusion or stenosis verified during femoral vein cannulation. Data from the history, clinical examination, procedure, and follow-up were recorded. Preoperative indicators of obstruction were venographic evidence of occlusion, stenosis, or pelvic collateral vessels; increased arm-foot venous pressure differential; and abnormal hyperemia-induced venous pressure elevation.

RESULTS

Cannulation and technical success rates were 98% and 97%, respectively, with 118 Wallstents deployed in 77 veins. Primary, assisted primary, and secondary patency rates at 1 year were 82%, 91%, and 92%, respectively. Clinical improvement in pain and swelling was significant.

CONCLUSIONS

Stenting of benign iliac vein obstruction is a safe method with good short-term results. Venous lesions should always be stented; when treating iliocaval junction lesions, stents should be inserted well into the inferior vena cava. Absence of collateral vessels does not exclude the existence of significant obstruction, and their presence may indicate an obstruction not visualized. No gold standard for accurate pre- or intraoperative patient selection is currently available.

Chronically occluded inferior venae cavae: endovascular treatment

PURPOSE

To report the results of endoluminal recanalization and stent placement in patients with chronic occlusions of the inferior vena cava (IVC).

MATERIALS AND METHODS

Seventeen consecutive patients (12 male, five female patients; mean age, 40.6 years; age range, 15-77 years) with chronic IVC occlusions were treated during a 6-year period. The mean duration of symptoms was 32 months. Underlying active malignancy was the cause of occlusion in four patients. Five patients with superimposed acute thrombus underwent catheter-directed thrombolysis prior to IVC recanalization. Clinical patency was defined as absence or improvement of symptoms. Clinical follow-up was supplemented with ultrasonography, vena cavography, or both in 10 patients.

RESULTS

Technical success was achieved in 15 (88%) patients. Additional thrombolytic therapy and stent placement was needed in two patients to maintain patency at 4 and 6 months after the procedure. Twelve patients had IVCs that remained patent after a mean follow-up of 19 months for a primary patency rate of 80%. The primary assisted patency rate was 87% (13 of 15). There were four deaths owing to underlying disease 6-21 months after the procedures. There were no procedure-related complications.

CONCLUSION

Endoluminal recanalization and stent placement in chronically occluded IVCs has a good intermediate-term outcome and should be considered in patients who have symptoms and who often do not have adequate alternative therapy.

Endovascular treatment of hepatic venous outflow obstruction after piggyback technique liver transplantation

BACKGROUND

The piggyback technique of orthotopic liver transplantation is an attractive alternative that preserves the recipient inferior vena cava and allows uninterrupted venous blood return during the anhepatic phase. As with other transplantation techniques, the vascular anastomoses required by the piggyback technique can develop strictures.

METHODS

Review of records of 264 piggyback transplantations revealed two cases of delayed-onset hepatic venous obstruction from anastomotic strictures. Both patients also had symptoms of inferior vena cava obstruction, with azotemia and lower extremity edema. Both patients were treated percutaneously with balloon-expandable stents.

RESULTS

Rapid, dramatic resolution of symptoms was achieved in both patients. Patients remain completely asymptomatic at 39 and 3 months of follow-up.

CONCLUSIONS

Hepatic venous anastomotic strictures in recipients of piggyback technique transplants are a very uncommon complication. They may be easily and effectively treated by minimally invasive endovascular intervention.

Percutaneous venous interventions

Percutaneous procedures by interventional radiologists are becoming an increasingly frequent part of the overall care of patients with complex venous thrombotic diseases. Inferior vena caval filters are used in the setting of failed or contraindicated anticoagulation. Catheter-directed thrombolysis is considered for patients with extensive iliofemoral deep venous thrombosis. Venous angioplasty is often indicated for patients with dialysis shunt venous stenoses, upper extremity venous stenoses and for stenoses within venous bypass grafts. Venous stenting is often employed following angioplasty to ensure long-term procedural success. Finally, suction and mechanical thrombectomy and embolectomy are relatively new procedures that are available to optimize patient management.