Iliac Stent Research Articles

Insights from Computational Fluid Dynamics and In Vitro Studies for Stent Protrusion in Iliac Vein: How Far Shall We Go?

These findings provide significant implications for the enhancement of iliac vein stent implantation strategies and stent design. The prevalent use of stents for treating Iliac Vein Compression Syndrome (IVCS) has shown efficacy, yet the associated clinical adverse events, including stent restenosis and postoperative thrombosis, are significant concerns. Up to now, the mechanism how the stent implantation induces the restenosis and DVT is still unclear. Our study hypothesizes that these adverse outcomes arise from altered blood flow dynamics following stent implantation. Employing computational modeling and medical imaging, we simulated IVCS after various stenting procedures to assess their impact on venous blood flow characteristics, including wall shear stress (WSS), residence time (RRT), and oscillatory shear index (OSI). Our findings reveal that a stent protruding into the vena cava impedes blood circulation, with increased protrusion exacerbating this obstruction. This is particularly evident at the vein bifurcation, where low WSS and elevated OSI and RRT are observed. Moreover, a higher stent strut density further obstructs blood flow, deteriorating the hemodynamic environment. Consequently, stent protrusion into the vena cava can enhance the likelihood of adverse post-surgical events. These insights have profound implications for optimizing iliac vein stent implantation techniques and stent design.

Long-term follow-up for the treatment of symptomatic pelvic venous insufficiency secondary to combined iliac vein stenosis and ovarian vein reflux treated with iliac vein stenting alone

BackgroundWe previously reported that in women with symptomatic pelvic venous insufficiency secondary to combined iliac vein stenosis (IVS) and ovarian vein reflux (OVR), treated with iliac vein stenting alone that 78% reported complete symptom resolution up to 6 months. The purpose of this investigation was to determine the long-term effectiveness of this treatment strategy, the poststent reintervention rate and the incidence of poststent ovarian vein embolization (OVE) for residual symptoms. MethodsA retrospective review of prospectively collected data at the Center for Vascular Medicine was performed. We investigated women with pelvic pain or dyspareunia secondary to combined IVS and OVR who were treated with stenting alone. Patients whose primary complaint was dysmenorrhea and/or leg symptoms were excluded from the analysis. Assessments and interventions consisted of an evaluation for other causes of pelvic venous disorder by a gynecologist, documentation of preintervention and 3-, 6-, 12-, 24-, and 36-month visual analog scale pain scores; transabdominal duplex ultrasound examination; stent type, diameter, and length; vein territory covered; and reintervention rates. All patients underwent diagnostic venography of their pelvic, left ovarian veins, and pelvic reservoirs, and intravascular ultrasound examination of their iliac veins. ResultsFrom February 2018 to January 2023, 141 women with a pelvic venous disorder secondary to IVS and OVR were identified. The average age was 44.7 ± 10.5 years with 3.18 ± 1.82 pregnancies. The average follow-up time for the entire cohort was 12.0 ± 12.1 months (median, 10.65 months). Types of stents were Venovo 48 (34%), Wallstent 14 (10%), and Abre 79 (56%). The most common diameter and stent lengths used were 14 and 16 mm and 140 and 150 mm, respectively. The most common vein territories covered were the inferior vena cava to the left external iliac vein in 83% and inferior vena cava to right external iliac vein in 13%. Pelvic and dyspareunia VAS scores before the intervention and at 3, 6, 12, 24, and 36 months after the intervention were as follows: 6.4 ± 73 (n = 141), 2.6 ± 3.3 (n = 98), 1.71 ± 2.83 (n = 77), 2.04 ± 3.5 (n = 76), 2.4 ± 3.7 (n = 30), and 1.15 ± 3 (n = 13) (P ≤ .001). Of the entire cohort no patients required OVE and pelvic reservoir embolization. Pelvic reservoirs were present in 113 of 141 patients (83%). Stent reinterventions were required in 19 of 141 patients (13%). ConclusionsThe majority of women with pelvic pain secondary to combined IVS and OVR achieved near complete symptom resolution with iliac vein stenting alone, despite the presence of a pelvic reservoir in 83% of patients. Although most women complained of some minimal residual pelvic pain or dyspareunia, the majority were satisfied with their outcomes and did not require further intervention. In this patient population, iliac vein stenting should be considered the primary treatment modality. OVE should be reserved for patients with persistent or recurrent pelvic pain unresolved with stenting.

Anticoagulation plus antiplatelet therapy versus anticoagulation alone following iliac vein stent implantation in acute and subacute deep vein thrombosis: A multicenter study with propensity score matching

BackgroundIliac vein stenting is an effective treatment for iliac venous stenosis after percutaneous mechanical thrombectomy. Nevertheless, while some researchers have investigated medical therapy following iliac vein stenting, no consensus has been reached to date. ObjectivesTo evaluate the effectiveness and safety of anticoagulation plus antiplatelet therapy following iliac vein stent implantation in patients with acute and subacute iliofemoral deep vein thrombosis (DVT). Materials and methodsThis retrospective study comprised 234 patients: 167 patients in Group 1 with a mean age of 64.3 ± 13.5 years received anticoagulants alone, and 67 patients in Group 2 with a mean age of 60.7 ± 15.4 years received anticoagulation plus antiplatelet therapy. All patients received technically successful percutaneous pharmacomechanical thrombectomy and iliac vein stent implantation, and 61 patients underwent additional catheter-directed thrombolysis. The two groups exhibited comparable demographics, comorbidities, DVT burdens, and procedural details. Through propensity score matching (PSM) analysis, 62 pairs of patients from Group 1 and Group 2 were matched. ResultsDuring a follow-up period of 33.7 ± 16.5 months, the cumulative primary patency rates were 95.1 %, 89.7 % and 88.3 % at one, three and five years in Group 1 compared to 98.8 %, 98.5 % and 98.5 % in Group 2 for the entire cohort (p = 0.042); in the PSM analysis, the rates were 91.9 %, 87.3 % and 87.3 % at one, three and five years in Group 1 versus 98.4 % at one, three and five years in Group 2 (p = 0.039). The cumulative bleeding-free rate was 98.2 % at one, three and five years in Group 1 versus 95.5 %, 93.8 % and 93.8 % at one, three and five years in Group 2 for the entire cohort (p = 0.089), and it was 98.4 % at one, three and five years in Group 1 versus 95.2 %, 93.3 % and 93.3 % (p = 0.156) at one, three and five years in Group 2 in the PSM analysis. ConclusionAnticoagulation plus antiplatelet therapy significantly improved stent patency, with a non-significant increase in the bleeding rate.

ILIAC VENOUS STENTING PROVIDES LONG TERM RELIEF FROM CHRONIC PELVIC PAIN

ObjectiveIliac Venous Obstruction (IVO) has been reported as a cause of chronic pelvic pain (CPP), however , there is a paucity of data in the literature reporting outcomes of venous stenting in this population. This study reports on a group of women with CPP and evidence of IVO: i) the long-term impact of iliac vein stenting on pain scores; ii) the associations of age, stenosis severity, and concurrent presence of ovarian vein reflux (OVR) on pain ; and iii) the effect of pregnancy post stenting. MethodsRetrospective analysis of prospectively collected data of women with chronic pelvic pain who subsequently underwent iliac vein stenting. Data analysed included demographics, venous measures (iliac and ovarian veins), visual analogue scales, and pregnancy post-stenting. ResultsA total of 113 female patients who had a history of chronic pelvic pain and underwent iliac venous stenting were included in analyses. Mean age at the time of stenting was 46.5 ± 15.7 years (range: 17 - 88 years). Baseline LCIV diameter on duplex was 0.43 ± 0.18 cm and LCIV area stenosis on IVUS was 77.4 ± 9.4%. Baseline pain severity was correlated with younger age, degree of stenosis and presence of OVR. At a median follow-up of 5 years post-stenting, 98% had improved pain scores, and 73% had complete resolution of their pain despite the presence of residual OVR . Pregnancy post-stenting did not result in recurrence of pain and there were no stent-related complications with pregnancy. ConclusionIliac venous stenting provides long term relief from CPP even with residual OVR and post-stent pregnancy. With 73% of women having full pain resolution, and the rest having a mean residual pain score of less than 3 , this study supports venous stenting for the treatment of CPP of venous origin, especially young women.

Iatrogenic migration of iliac stent graft that was implanted for the reason of iliac artery perforation at the beginning of TAVI into the ascending aorta during the procedure

Abstract Introduction Vascular complications are one of the substantial complications of transcatheter aortic valve implantation (TAVI). Stent graft implantation is a powerful tool for managing them. Case presentation This article describes a case of iliac artery perforation by 10 Fr sheath in an 86-year-old female at the beginning of the TAVI procedure that was solved by stent graft implantation. However, the stent graft was later unintentionally dislocated into the ascending aorta during repeated attempts of sheath and guiding wire introduction. Finally, the migrated stent graft was successfully extracted using a loop snare device. Conclusions This article highlights the fact that armamentarium passage through an implanted stent graft, especially when newly deployed, can be tricky and should be done gently and carefully, optimally under fluoroscopic guidance. The permanent multidisciplinary team realizes TAVI can be advantageous for immediate management of difficult clinical situations.

The effects on clinical outcomes of administering medications together or separately in prolonged dual antiplatelet therapy after peripheral revascularisation.

In the current guidelines, dual antiplatelet therapy [acetylsalicylic acid (ASA) + clopidogrel] is recommended for at least three months after peripheral iliac stenting. In this study, we investigated the effect on clinical outcomes of adding ASA in different doses and at different times after peripheral revascularisation. Seventy-one patients were administered dual antiplatelet therapy after successful iliac stenting. Group 1, consisting of 40 patients, was given 75 mg of clopidogrel plus 75 mg of ASA in a single dose in the morning. In group 2, separate doses of 75 mg of clopidogrel (in the morning) and 81 mg of 1 × 1 ASA (in the evening) were started in 31 patients. The demographic data and bleeding rates of the patients after the procedure were recorded. The groups were found to be similar in terms of age, gender and accompanying co-morbid factors (p > 0.05). The patency rate was 100% in the first month in both groups, and it was above 90% at the sixth month. When one-year patency rates were compared, although the first group had higher rates (85.3%), no significant difference was found (p < 0.05). However, there were 10 (24.4%) bleeding events in group 1, and five (12.2%) of these were in the gastrointestinal system, resulting in reduced haemoglobin levels (p = 0.038). ASA doses of 75 mg or 81 mg did not affect one-year patency rates. However, higher bleeding rates were observed in the group that received both clopidogrel and ASA treatment simultaneously (in the morning) despite the lower dose of ASA.

Successful use of lithoplasty for re-expansion of covered iliac stents with unilateral occlusion.

Vessel wall calcification is associated with stent under-expansion and in-stent restenosis. The traditional approaches to treat peripheral artery calcification are percutaneous transluminal angioplasty (PTA) and atherectomy. Shockwave intravascular lithotripsy (IVL) uses sonic wave pressure to disrupt calcium of the severely calcified lesions. Published reports of IVL to treat in-stent restenosis are limited to coronary interventions and bare metal platforms. We describe the case of a 55-year-old male with extremely compressed under-expanded covered stents associated with severe wall calcification that resulted in stent occlusion. The IVL system balloon was deployed uneventfully, in a phased manner. Bilateral bare metal stents were also placed in a kissing fashion to further re-expand the arterial segments. Reintervention with IVL facilitated successful revascularization and the stent remained patent at 24 months. Our case highlights the use of IVL as an effective tool in the management of vessel wall calcification both for primary and secondary interventions.

Efficacy of ultrasound in the evaluation of iliac vein stenting.

Objectives: The current study evaluated the efficacy of iliac and IVC ultrasound alone for follow-up evaluation of iliac vein stents in patients with pelvic venous disorders or iliac occlusion from chronic deep vein thrombosis. Methods: A retrospective single site cohort study was conducted by evaluating the most recent 100 iliac vein and inferior vena cava ultrasounds in patients who had undergone iliac vein stenting. Inclusion criteria included a history of iliac vein stent placement. Exclusion criteria included patients under 18-years-old, duplicates of the same patient, and pregnancy at the time of ultrasound. The degree of visualization for color flow, gray scale, and phasicity were determined and classified into the following categories: complete, partial, or none. In addition, each chart was assessed for external compression, in-stent narrowing, and requirements for further imaging. Results: Of the 100 iliac vein and IVC ultrasounds assessed in this review, 99 of the ultrasounds were sufficient for evaluation during follow-up visits without requiring further investigation. Within this study cohort, the average follow-up time was 22months. The average participant body mass index was 27.6. One iliac vein and IVC ultrasound was considered inadequate for follow-up evaluation and required further imaging. Conclusion: The use of iliac and IVC venous doppler ultrasound alone in the follow-up evaluation of iliac stent patency is effective and noninvasive and avoids unnecessary radiation exposure and cost.

Venous stenting versus venous ablation.

The minimally invasive procedures of venous ablation and iliac vein stenting are evolving treatment options for venous insufficiency. Yet, there are no studies directly comparing the outcome of these procedures. We performed a survey on patients who had both procedures, to determine if either procedure helped more and if there is any other clinical factor related to the outcome. We collected data between Jan 2012 and Feb 2019 from 726 patients who failed to improve swelling after conservative management. The patients underwent iliac vein stenting and vein ablations. We recorded patient assessment of the leg immediately after completion of both procedures. Follow-up was performed using in-person questionnaires by asking if improvement in lower extremity swelling occurred and if so, which procedure helped more. Of the 726 patients who underwent endovenous closure and iliac vein stent placement, 254 (35%) were males. The average age of the patients was 70 (±13.7 SD, range 29-103) years. The presenting symptom (C of CEAP classification) of lower extremity limb venous disease was 34.8%, 44.6%, 5.6%, and 15% for C3-C6, respectively. Patients were asked about swelling, and they stated: swelling is better (605, 83.3%), swelling is not better (118, 16.3%), and not sure if there is any improvement in swelling (3, 0.4%). Patients stated the following completion of both procedures: both procedures equally helped (129, 18%), iliac vein stent superior (167, 23%), endovenous ablation superior (177, 24%), neither helped (112, 16%), and not sure which procedure helped more (141, 19%). After ANOVA, we concluded that older patients (average = 72.5 years) were more often not sure which procedure helped more (p = .024), and younger patients (average = 68.4years) stated that endovenous ablation helped more (p = .014). There were no significant differences between the groups regarding gender (p = .9), laterality (p = .33), or presenting symptoms scores (p = .9). There was no statistical relationship between the procedure that was performed first and the procedure that helped more (p = 0.095). In this qualitative assessment, preliminary data suggest that the comparative role of iliac vein stent versus endovenous ablation warrants further study. The data were broadly distributed, and neither procedure was superior. In addition, 16% of the patients stated that neither procedure helped. The age of patients may also play a role in their procedure preferences and their subjective assessment for improvement.

Prospective Cohort Study of a Treatment Strategy for a Combination of the Left Common Iliac Vein Compression Stenosis and Pelvic Venous Insufficiency.

To develop a strategy for the iliac vein stenting in patients with a combination of the left common iliac vein (LCIV) compression stenosis and pelvic venous insufficiency (PVI). This prospective comparative cohort study included 55 patients with hemodynamically significant LCIV stenosis out of 285 females with PVI screened in 2014-2022. All 55 patients underwent duplex ultrasound, multi-detector computed venography, ovarian venography, and multiplanar pelvic venography. Patients underwent LCIV stenting or the left gonadal vein (LGV) embolization as the primary intervention. The endpoints (chronic pelvic pain [CPP] relief, patency of stents, and reduction in pelvic venous reflux [PVR]) were evaluated 1 and 10 days, as well as 1, 6, and 12 months after the procedure. All patients received antithrombotic therapy after the interventions. The primary LCIV stenting was performed in 49 patients and resulted in the CPP relief in 69.4%, pain reduction from 7.9±1.3 to 1.7±1.1 visual analog scale (VAS) scores (p=0.005), and substantial reduction of PVR in LGV (from 4.3±0.6 seconds to 1.9±0.3 seconds, p=0.003). The LGV embolization as the second stage of treatment was performed in 30.6% of patients with the LGV reflux greater than 5 seconds as a possible cause for the CPP persistence. The primary LGV embolization failed in 100% of patients (no changes in CPP and PVR). The LCIV stenting at the second stage resulted in the CPP relief within 10 days and the pelvic venous reflux (PVR) reduction. There were no complications of stenting, and the patency of stents in the follow-up period was 100%. Postembolization syndrome occurred in 9.5% of patients. No thromboses of the veins of the pelvis and lower extremities were identified. Treatment of patients with a combination of LCIV compression and PVI involves staged endovascular interventions: the LCIV stenting should be considered the first-line treatment, while the LGV embolization is performed when the PVI symptoms persist for more than 6 months and is not acceptable as the first-line treatment. The developed strategy of endovascular treatment for the combination of left common iliac vein (LCIV) and pelvic venous insufficiency (PVI) provides an effective elimination of chronic pelvic pain (CPP) and reflux in the pelvic veins and avoids unnecessary embolizations of the gonadal veins, thereby eliminating possible risks related to complications of embolization. The use of antithrombotic therapy is an effective and safe approach for preventing venous thromboembolic events after endovascular interventions.

The impact of stent protrusion into the inferior vena cava or jailing of the contralateral iliac vein on the incidence of contralateral deep vein thrombosis following venous stenting.

Iliac vein stenting is the standard of care for patients with pelvic venous disorders secondary to symptomatic iliac vein outflow obstruction. Venous stents are often extended proximally into the inferior vena cava (IVC) which may result in partial or complete coverage of the contralateral iliac vein. The purpose of this investigation is to determine if extension of iliac vein stents into the IVC results in increased risk of contralateral deep venous thrombosis (DVT). We retrospectively reviewed prospectively collected data from 409 patients who underwent iliac vein stenting at the Center for Vascular Medicine (CVM) from 2019 to 2020. Stent type, covered territories, initial and follow-up consults, ultrasound and operative reports were reviewed to assess for incidence of post-implantation DVT. Patients were stratified into three groups: Iliac vein stents which protruded into the IVC, stents that completely covered the orifice of the contralateral iliac vein and those with no stent protrusion into the IVC. Out of 409 patients, the average age was 53.96 ± 13.40 years with 94 males and 315 females. All stents placed were Venovo stents and all iliac vein lesions were non-thrombotic stenoses. The average follow-up period was 14.35 ± 10.09 months. The most common territories stented were the IVC-LCIV-LEIV (n = , 74%) and the IVC-RCIV-REIV (n = , 26%). Stent protrusion and distance into the IVC in millimeters (mm) was the following: Partial protrusion (n = 314, 77%, 27.6 ± 19.1), jailing of the contralateral iliac vein (n = 78, 19%, 45.9 ± 18.6), no protrusion (n = 16, 4%). The overall DVT rate post-implantation was 0.49% (n = 2). No DVTs ipsilateral to the index stent were identified and both DVTs were contralateral DVTs. A hypercoaguable disorder was reported in 6 patients (1.5%). There were no significant differences in prevalence of contralateral DVT between the three groups. (p = .35). The rate of contralateral DVTs post iliac vein stenting with Nitonol based stents is extremely low. Partial or complete coverage of the contralateral iliac vein via stenting does not result in an increased incidence of contralateral DVT in the short-term. Longer follow up is needed to determine if contralateral DVTs occur after long-term implantation.

Nickel allergy in a patient after nitinol stent placement

We report a case involving a patient who developed a polymorphic rash and prurigo lesions on the limbs and anterior thorax, accompanied by an urticarial reaction on the back, following the endovascular placement of a femoral and iliac nitinol stent for critical limb ischemia. Patch testing identified a nickel allergy. The patient responded well to corticosteroid therapy, showing significant clinical improvement. This report discusses the epidemiology, pathophysiology, and clinical implications of nickel allergy, particularly in the context of using nickel-alloy stents.

Staged versus nonstaged elective hybrid iliofemoral revascularization – analysis of ten years of prospective data

Reports of large series of hybrid iliofemoral revascularization for chronic lower limb ischemia are scarce. The aims of this study were to evaluate outcomes for staged and non-staged procedures, and to evaluate risk factors for outcomes at 90 days. Patients were consecutively included between 2013 and 2023. Surgical site infection (SSI) was defined by the ASEPSIS criteria and major adverse limb events (MALE) as onset of acute or continuing or worsening chronic limb ischemia or major amputation. Factors associated with outcomes were tested in a multivariable logistic regression analysis and expressed in Odds ratios (OR) with 95% confidence intervals (CI). Patients undergoing non-staged procedures (n=124) had higher TASC (Trans-Atlantic Inter-Society Consensus) class representing anatomical occlusive complexity, more often through-and through femoral guidewire access, more endoprosthesis, more covered stents, longer procedure time with open groin wounds, and less contralateral femoral access, than those undergoing staged procedures (n=31). The median time interval between the staged procedures was one day, and iliac stenting was done first in 77%. The median in-hospital stay was non-significantly longer in staged procedure (8 versus 6 days, p=0.053). The overall SSI and MALE rates were 25.8% and 20.0%, respectively, without differences between groups. Diabetes mellitus (OR 3.7, 95% CI 1.2 - 7.2]) and presence of a foot ulcer (OR 3.7, 95% CI [1.5 - 9.4]) were independently associated with MALE at 90 days. Postoperative hyperglycemia was non-significantly associated with SSI (OR 2.1 [95% CI 1.0 - 4.5], p=0.066) in multivariable analysis. The risks of SSI and MALE after elective hybrid iliofemoral revascularization were high. There appears to be no benefit in performing staged as opposed to non-staged procedures. The extent of iliofemoral occlusive disease according to the TASC classification had little influence on outcomes whereas diabetes mellitus and presence of a foot ulcer had greater impact on MALE.

Current Diagnostic and Therapeutic Approaches in May-Thurner Syndrome in Children, Adolescents, and Young Adults: A Survey among Thrombosis Experts of the German Society of Thrombosis and Haemostasis.

May-Thurner syndrome (MTS) is a pelvic venous disorder involving compression of the left common iliac vein by the right common iliac artery, which results in predisposition for deep vein thrombosis. Although MTS is increasingly recognized in young patients, specific guidelines on diagnosis and management for children, adolescents, and young adults do not exist so far. The aim of this study was to assess current diagnostic and therapeutic practice in Germany, Austria, and Switzerland in children and young adults with thrombosis and MTS.We designed an online survey with 11 questions, which we sent via a mailing list to all members of the German, Austrian, and Swiss Society of Thrombosis and Haemostasis Research. Between July and October 2022, 33 specialists answered the questionnaire. Most participating specialists worked at pediatric hospitals (61%). Numbers of annually treated thromboses ranged from <5 (26%) to >30 (13%). Most specialists used venous ultrasound to diagnose deep vein thrombosis, 53% magnetic resonance imaging. Only 25% of specialists systematically screened for MTS in deep vein thrombosis. MTS was managed with anticoagulation (65%), iliac vein stent placement (32%), or balloon angioplasty (13%). In total, 31% of specialists reported to use more than one therapeutic method. Diagnostic and therapeutic approaches for MTS differed between specialists. Lack of standardization resulted in individualized and highly diverse management. Prospective observational clinical studies investigating the outcome of different management strategies including long-term follow-up on outcome and incidence of postthrombotic syndrome will help in defining patient groups who benefit most from revascularizing interventional strategies and developing standardized guidelines.

Covered Endovascular Reconstruction of the Iliac Artery Bifurcation (CERIB).

The aim of this study was to present the covered endovascular reconstruction of the iliac artery bifurcation (CERIB) technique as a revascularization option for aorto-iliac occlusive disease (AIOD) involving the iliac artery bifurcation. This was a retrospective single-center study including all patients undergoing a CERIB procedure from January 2021 until December 2022. Covered endovascular reconstruction of the iliac artery bifurcation procedures were performed percutaneously with bilateral femoral access, excepting cases where simultaneous open femoral artery reconstruction was required due to the extension of peripheral arterial occlusive disease. Standard patient, procedural, and follow-up (FU) data including survival and arterial reinterventions were gathered and analyzed. A total of 13 patients were included (11/13 male, median age=70 [60-76] years). Additional open and/or endovascular procedures included endarterectomy of the femoral bifurcation (n=6), rotational atherectomy (n=2), and 1 axillary artery cutdown for upper limb access (n=1). Median operating time was 2.9 hours (1.5-4.9 hours); median radiation duration and dose were 28.4 (14.3-63.3 minutes) and 4090.6 (384.4-9430.1 cGray/cm2), respectively. The stent grafts used for CERIB were BeGraft peripheral n=31, BeGraft Aortic n=4 and BeGraft peripheral plus n=1 (Bentley InnoMed GmbH, Hechingen, Germany). In 2 patients with prior stenting of the common iliac artery (CIA), only the internal and external iliac arteries (IIA and EIA) were treated in this study, and in 2 cases, additional uncovered stents were required for relining. Technical success was 100%. During a midterm FU (median 18 [4-31] months), 2 patients died from cardiovascular reasons and 1 patient with prior iliac stenting required reinterventions for recurring occlusion. Covered endovascular reconstruction of the iliac artery bifurcation is a straightforward option for treating AIOD involving the iliac artery bifurcation that allows preservation of internal iliac artery perfusion and shows good early and midterm results. Prior iliac artery stenting may be a risk factor for early occlusion after CERIB. Aorto-iliac occlusive disease with involvement of the internal iliac artery is encountered regularly in vascular surgical practice, but the internal iliac artery is often not included in the revascularization strategy. The present article will increase the awareness for the relevance of including the internal iliac artery in revascularization strategies and presents CERIB as another method to be added to the armamentarium of (endo-)vascular surgeons and interventionalists.

Cook Zenith Alpha Endograft: A Protocol to Minimise Limb Graft Occlusion

Numerous articles have reported an increased incidence of limb graft occlusion (LGO) with the Cook Zenith Alpha endograft compared with other endografts in endovascular aortic aneurysm repair (EVAR). The present study aimed to assess the rate of LGO after EVAR in particular with the Cook Zenith Alpha device when adhering to a standardised protocol designed to prevent limb related complications. This was a non-sponsored retrospective study performed in two university vascular surgery centres employing the same protocol for limb complication prevention during EVAR from 2016 to 2019. The protocol encompassed: (1) angioplasty of any common or external iliac artery with > 50% stenosis before endograft navigation; (2) proximal sealing zone of limbs at the same level of the flow divider with minimum overlap, which is more restrictive than the Cook Zenith Alpha instructions for use; (3) semi-compliant kissing ballooning of limbs; (4) limb stenting for any residual tortuosity, kinking, or stenosis; and (5) adjunctive common and external iliac stenting for residual stenosis or dissection after EVAR. Patients enrolled in this study were treated with standard aortobi-iliac EVAR. Follow up was performed by clinical visit and duplex ultrasonography at discharge, six months, and yearly thereafter. The primary endpoint was to evaluate the LGO rate with different EVAR devices (Cook Zenith Alpha, Gore C3, and Medtronic Endurant) and to determine potential risk factors for LGO associated with the Zenith Alpha. In the study period, 547 EVARs were considered: 233 (42.6%) Cook Zenith Alpha, 196 (35.8%) Gore Excluder,and 118 (21.6%) Medtronic Endurant. The mean follow up was 44 ± 23 months, and the five year freedom from LGO was 97 ± 3%, without differences between groups (97 ± 2%, 95 ± 3%, and 100% with Cook Zenith Alpha, Medtronic Endurant, and Gore Excluder, respectively; p= .080). In the Zenith Alpha group, intra-operative adjunctive iliac artery angioplasty, iliac artery stenting, or iliac limb stenting was performed in 8%, 3.4%, and 9.7% of cases, respectively. Analysis of potential risk factors for LGO identified external iliac artery distal landing and large main bodies (ZIMB 32 - 36) to be independently associated with LGO during follow up (hazard ratio [HR] 18, 95% confidence interval [CI] 3 - 130, p= .004; and HR 12, 95% CI 1.2 - 130, p= .030, respectively). The present experience with a protocol for limb complication prevention allows achievement of a low rate of LGO at five years with Zenith Alpha endografts similar to other endografts. Specific risk factors for the Cook Zenith Alpha endograft are external iliac artery distal landing and the use of a large main body (ZIMB 32 - 36).

Lower extremity woven and nonwoven venous stent morphology and luminal changes

ObjectiveVenous stents are a common treatment modality for obstructive venous disease. Venous stents differentiate themselves by either a woven or braided structure, open or closed cell arrangement or based on material composition (elgiloy vs nitinol). Changes in the morphology of venous stents over time may contribute to restenosis or thrombosis. Woven elgiloy stents are prone to proximal and distal edge deformation compared with dedicated venous stents, which offer increased radial force at stent edges. The objective of this study is to describe luminal morphological changes among various venous stents and between woven to nonwoven venous stent configuration, over time. MethodsA retrospective review at a single institution between January 2014 and June 2021 identified patients treated with venous stents. Patients with iliac and/or femoral venous stents with intraoperative intravascular ultrasound and a postoperative computed tomography scan were included in the study. Cross-sectional diameters measurements were taken at proximal, middle, and distal portions of each stent from intravascular ultrasound examination at the time of initial stenting and compared with the cross-sectional diameter measurements taken from computed tomography imaging at follow-up. A paired t test was used to compare the luminal change with a D'Agostino-Pearson test used for normality. ResultsFifty-four stents distributed among 38 patients were identified. The mean time to follow-up was 17.5 months. Stents were placed in the common iliac vein (n = 37, 68.5%), external iliac vein (n = 14, 25.9%), and common femoral vein (n = 3, 5.6%). Implanted stents included the Boston Scientific Wallstent (n = 23, 42.6%), Bard Venovo (n = 3, 5.6%), Boston Scientific Vici (n = 23, 42.6%), and Medtronic Abre (n = 5, 9.3%). The mean luminal loss was measured at 2.12 mm proximally (95% confidence interval [CI], 1.64-2.60; P<.001), 1.29 mm at the mid-stent (95% CI, 0.83-1.74, P<.001), and 1.56 mm distally (95% CI, 0.99-2.12; P<.001). There was no significant difference in luminal changes between woven and nonwoven stents at proximal (P = .374), middle (P = .179), and distal (P = .609) stent measurements. ConclusionsThis study reports morphological changes within venous stents and between woven and nonwoven venous stents. Our findings demonstrate that the edge-stent luminal decrease traditionally attributed to woven configurations also occurs with the newer nonwoven stents. Additional factors such as anatomical location, pelvic curvature, and other external forces may be accountable for this change rather than geometrical configuration of the stent.

Recanalization of superficial femoral artery chronic total occlusion through retrograde popliteal approach recanalization of superficial femoral artery chronic total occlusion

PurposeThis retrospective study aims to evaluate the safety, practicality, and efficacy of the independent retrograde popliteal approach for recanalization superficial femoral artery (SFA) occlusions when the bilateral common femoral artery approach is unavailable, such as after endovascular aneurysm repair or common iliac artery stenting. MethodsThis treatment was considered for patients with contralateral iliac artery occlusion, severe iliac tortuosity, or those who had previously undergone endovascular aneurysm repair or common iliac stenting. Patients with SFA lesions extending into the P1–P2 segment of the popliteal artery or with calcification in the P3 segment were excluded. Angioplasty and stenting were conducted via the popliteal artery approach, with hemostasis at the puncture site achieved using an EXOSEAL vascular closure device. Patients were routinely followed up at 3, 6, and 12 months, and annually thereafter. ResultsForty-eight consecutive patients with SFA occlusion who underwent endovascular treatment via the retrograde popliteal artery approach were included in this study. Retrograde puncture of the popliteal artery was successful in all cases. Six-French sheaths were utilized in all procedures. The EXOSEAL vascular closure device was successfully applied in all 48 cases. No instances of pseudoaneurysms, arteriovenous fistulas, major bleeding, or embolic complications were observed. The technical success rate for SFA recanalization was 100 %. All patients experienced clinical improvement. The ankle-brachial index significantly increased from an initial 0.33 ± 0.11 at admission to 0.81 ± 0.19 at discharge (P < 0.001). The mean follow-up period was 25.1 ± 11.7 months. Kaplan-Meier analysis revealed primary patency rates of 82.5 % at 12 months and 71.8 % at 24 months. No patients required major amputation during the follow-up period. ConclusionThe endovascular treatment of SFA occlusions via the independent retrograde popliteal approach is a viable alternative, demonstrating a low incidence of puncture-related complications and a high success rate of recanalization.

The Safety and Efficacy of ZelanteDVT™ Catheter Rheolytic Thrombectomy in the Treatment of Patients with Iliac Vein Stent Thrombosis

ObjectiveTo examine the safety and efficacy of ZelanteDVT™ catheter rheolytic thrombectomy in the treatment of patients with iliac vein stent thrombosis. MethodsA retrospective analysis method was conducted by means of collecting the data of 32 patients who had completed the treatment of iliac vein stent thrombosis with ZelanteDVT™ catheter rheolytic thrombectomy from March 2019 to March 2023. Data on clinical characteristics, technical success, clinical success, complications, and early follow-up were analysed. ResultsThe technical success rates were 100%, intraoperatively, in which 22 cases were improved to thrombus clearance Grade II (50-90%), 10 were Grade III (＞90%). There were 21 cases treated with subsequent catheter directed thrombolysis (CDT), and the average urokinase administration of (120.90±29.63)*10ˆ4 units. The clinical success rates were 100% and the swelling of the affected limbs were significantly improved, a significant difference in the pre/post-operative between-thigh circumference difference [(5.16±1.08) vs (1.75±0.84), P＜0.000]. The pre/post-operative VCSS was [ (12.94±1.70) vs (7.44±1.31), P＜0.000]. No serious complications occurred during the perioperative period. The post-operative and 12-month stent patency rate was 100.00% (32/32) and 71.88% (23/32), respectively. ConclusionThe ZelanteDVT™ catheter rheolytic thrombectomy seems to have a promising application prospect for the treatment of patients with iliac vein stent thrombosis.

Pivotal Evaluation of Novel Dedicated Venous Stent for Iliofemoral Venous Obstruction: A Prospective Cohort Study.

The purpose was to evaluate the clinical outcomes of a dedicated venous stent with the tripartite composite segments for the treatment of iliofemoral venous obstruction (IVO) in a mixed cohort of nonthrombotic iliac vein lesion (NIVL) and post-thrombotic syndrome (PTS) over a period of 12 months. The Grency Trial is a prospective, multicenter, single-arm, open-label, pivotal study, which was conducted at 18 large tertiary hospitals in China from August 2019 to October 2020. A total of 133 hospitalized patients were screened and 110 patients with clinical, etiology, anatomical, and pathophysiology clinical class (CEAP) clinical grade C>3 and iliac vein stenosis >50% or occlusion, including 72 patients with NIVL and 38 patients with PTS, were implanted with Grency venous stents. Primary endpoint was stent patency at 12 months follow-up, and secondary outcomes were technical success; improvement in venous clinical severity score (VCSS) at 3, 6, and 12 month follow-up; and rates of clinical adverse events. Among 110 patients who were implanted with Grency venous stents, 107 patients completed the 12 month follow-up. All 129 stents were successfully implanted in 110 limbs. Twelve-month primary patency rate was 94.39% [95% confidence interval [CI]=88.19%-97.91%] overall, and 100% [94.94%-100%] and 83.33% [67.19%-93.63%] in the NIVL and PTS subgroups, respectively. Venous clinical severity score after iliac vein stenting improved significantly up to 12 months follow-up. There were 3 early major adverse events (1 intracerebral hemorrhage and 2 stent thrombosis events related to anticoagulation therapy), and 7 late major adverse events (1 cardiovascular death, 1 intracranial hemorrhage with uncontrolled hypertension, and 5 in-stent restenosis cases without stent fractures or migration). The Grency venous stent system appeared excellent preliminary safe and effective for IVO treatment. Further large-scale studies with longer-term follow-up are needed to evaluate long-term patency and durability of stent. The design of venous stents for iliofemoral venous obstruction (IVO) must address engineering challenges distinct from those encountered in arterial stenting. The Grency venous stent, a nitinol self-expanding stent specifically tailored for IVO, features a composite structure designed to meet the stent requirements of various iliac vein segments. The Grency Trial is a prospective, multicenter, single-arm, open-label pivotal study aimed at evaluating the efficacy and safety of the Grency stent system. Following a 12-month follow-up period, the Grency venous stent system has demonstrated both safety and efficacy in treating iliofemoral venous outflow obstruction.