Venous Stenting Research Articles

Dural Venous Sinus Stenting in Idiopathic Intracranial Hypertension: A National Database Study of 541 Patients.

Dural venous sinus stenting (VSS) is an effective intervention for patients with idiopathic intracranial hypertension (IIH) refractory to medical treatment. Our goal was to evaluate the efficacy by utilizing a large multi-institutional sample. Five hundred forty-one patients >18years old who underwent VSS within 3years of IIH diagnosis were queried using Current Procedural Terminology and International Classification of Diseases, Tenth Revision codes from the TriNetX Analytics Network. Patient demographics, baseline symptoms, procedures, and clinical outcomes were evaluated within 1 year postoperatively. Outcomes examined were headache, tinnitus, blindness/low vision, optic nerve sheath fenestration (ONSF), cerebrospinal fluid (CSF) shunt, and use of medications (acetazolamide, methazolamide, furosemide, topiramate, tricyclic antidepressants, and valproate) for IIH. Prestent and poststent data were compared using Fisher exact test, and the odds ratios were computed using the Baptista-Pike method. The mean age at VSS was 36.7±10.6; 92% were female, 65% of patients were Caucasian, 25% were Black/African American, 1% were Asian, and 9% were of other/unknown race. Within the 1-year follow-up, acetazolamide and topiramate use were significantly reduced post-VSS (P < 0.0001∗; odds ratio, 0.45; confidence interval, 0.35-0.57 and P= 0.03∗; odds ratio, 0.71; confidence interval, 0.52-0.95, respectively). Also, headaches, visual disturbance, dizziness/giddiness, and tinnitus significantly improved post-VSS (P < 0.005∗). Finally, the number of CSF shunt procedures and ONSF procedures demonstrated no significant change post-VSS (P > 0.05). VSS is an effective and safe procedure resulting in significant improvement of headaches, visual impairment, dizziness, and tinnitus, acetazolamide and topiramate usage were lower after VSS in patients with IIH. The paucity of pre-VSS and post-VSS CSF shunt and ONSF procedure data does not provide enough evidence to establish significance.

Venous Stent Migration of the Right Ventricle

Peripheral migration of a venous stent to the heart is a rare but known complication, with the heart being the most common site of landing. Echocardiographic modalities are essential in clinical diagnosis and management, particularly with limited data and consensus regarding the best management approach. (Level of Difficulty: Intermediate.)

External iliac vein dimensions can change after placement of a more proximal iliac vein stent

ObjectiveWe have occasionally observed during vein stenting for proximal iliac vein stenosis, the appearance of a more distal stenosis in the iliac vein that had not been initially observed before placement of the more proximal vein stent. In the present retrospective study, we aimed to document this observation. MethodsWe identified patients in whom changes in the area measurement and linear dimensions of the external iliac vein (EIV) were observed on venography and/or intravascular ultrasound (IVUS) after stent placement for chronic nonthrombotic iliac stenosis in the common iliac vein (CIV). The images of these IVUS scans were subsequently analyzed to determine the cross-sectional area, major axis, and minor axis measurements in the EIV, before and after placement of a proximal CIV stent. ResultsA total of 32 limbs with complete and quality IVUS and venography images available that allowed for measurement of the EIV before and after vein stent placement in the CIV were evaluated. The patient cohort was 55% men, with a mean age of 63.8 ± 9.9 years and a mean body mass index of 27.8 ± 7.8 kg/m2. Of the 32 limbs, 18 were left sided and 14 were right sided. Most (n = 12 [60%]) of the limbs had presented with venous-related skin changes (C4 disease). The remainder of the cohort had had active (C6 disease; n = 4 [20%]) or recently healed (C5 disease; n = 1 [5%]) venous ulceration and isolated venous-related edema (C3; n = 3 [15%]). The minimal CIV area before and after CIV stenting was 28.47 ± 23.53 mm2 and 196.34 ± 42.62 mm2, respectively. The minimal mean EIV cross-sectional area before and after CIV stenting was 87.44 ± 38.55 mm2 and 50.69 ± 24.32 mm2, respectively, a statistically significant reduction of 36.75 mm2 (P < .001). The mean EIV major axis and minor axis had both decreased similarly. The minimal mean EIV major axis before and after CIV stenting was 15.22 ± 3.13 mm and 11.13 ± 3.58 mm, respectively (P < .001). The minimal mean EIV minor axis before and after CIV stenting was 7.26 ± 2.40 mm and 5.84 ± 1.42 mm, respectively (P < .001). ConclusionsThe results from the present study have shown that the dimensions of the EIV can change significantly after placement of a proximal CIV stent. Possible explanations include masked stenosis due to distal venous distention resulting from the more proximal stenosis, vascular spasm, and anisotropy. The presence of proximal CIV stenosis can potentially lessen the appearance, or completely mask the presence, of an EIV stenosis. This phenomenon appears unique to venous stenting, and the prevalence is unknown. These findings underscore the importance of completion IVUS and venography after venous stent placement.

Estimation of venous sinus pressure drop in patients with idiopathic intracranial hypertension using 4D-flow MRI.

We aimed to explore a non-invasive estimate of pressure drop in patients who undergo venous sinus stenting to treat idiopathic intracranial hypertension (IIH). This prospective study included 28 IIH patients scheduled for venous stenting. 4D-flow MRI was acquired 24-48 h before venous manometry. Manometry-obtained pressure drop (Mp) was dichotomized into low (Lp: 0-8 mmHg) and high (Hp: 8-30 mmHg) groups. Hemodynamic indices were compared between Lp and Hp. Trans-stenotic pressure drop was estimated by work-energy equation, simplified Bernoulli equation, vorticity magnitude, and velocity difference between inlet and outlet and was compared with Mp. Measurement agreement, correlation, and accuracy were evaluated using the κ coefficient, Pearson's r, and confusion matrix-derived accuracy. Among 28 patients (mean age 38.8 ± 12.7), 19 (67.9%) were female. Work-energy equation-estimated pressure drop (WEp) had strong correlation (r = 0.91, 95% confidence interval [CI]: 0.81-0.96, p < 0.001) and high agreement (intraclass correlation coefficient = 0.90, 95% CI: 0.78-0.95, p < 0.001) with Mp. WEp classified Lp and Hp with an accuracy of 0.96. The κ value between WEp and Mp was 0.92 (95% CI: 0.78-1.00). In the work-energy equation, the viscosity energy term (Ve) had the largest weights, and the ratio of Ve to the summation of the three energy terms was 0.93 ± 0.07. Ve had strong correlation with mVort (r = 0.93, 95% CI: 0.85-0.97, p < 0.001), and mean vorticity magnitude was significantly elevated in Hp compared to that in Lp (259.8 vs. 174.9 mL/s, p < 0.001). Trans-stenotic pressure drop in IIH can be estimated using the work-energy equation with favorable accuracy. • Trans-stenotic pressure drop in patients with idiopathic intracranial hypertension can be estimated accurately with the work-energy equation using the 4D-flow MRI full velocity field. • Compared with traditional venous sinus manometry, the 4D-flow MRI-derived pressure drop is totally non-invasive and cost-saving. • 4D-flow MRI may help neurointerventionalist to select IIH patients suitable for venous sinus stenting.

Clinical tolerance of untreated reflux after iliac vein stent placement

BackgroundWe have recently demonstrated in a large patient cohort that the prevalence and severity of reflux will improve in most limbs after stenting and that most limbs will not develop new-onset reflux. In the present report, we have focused on the long-term clinical outcomes associated with untreated reflux in the same patient cohort who had undergone iliofemoral venous stenting without correction of residual reflux. MethodsThe clinical outcomes data from 1379 limbs treated with only iliac vein stenting without correction of superficial or deep reflux from 1997 to 2018 were analyzed (23-year follow-up period). Of the 1379 limbs, 632 (46%) had had preexisting reflux before stenting and 747 (54%) had did not. The reflux data (reflux segmental score, air plethysmography, ambulatory venous pressure) for these patients have been previously reported in detail. The subsets were compared perioperatively with each other using the following variables: grade of swelling, visual analog scale for pain score, venous clinical severity score, venous stasis dermatitis, ulceration, and quality of life measures. ResultsBoth groups demonstrated improvements in the venous clinical severity score, grade of swelling, visual analog scale score, and quality of life. No differences were found in ulcer healing (5% vs 3% for limbs with and without prestent reflux, respectively) and resolution of dermatitis (6% vs 5% for limbs with and without prestent reflux, respectively) between the two groups. Of the 632 limbs with preexisting reflux, 218 (34%) had had axial reflux and 414 had had nonaxial reflux (66%). The clinical outcomes were similar between the two groups. Using a multisegment reflux score, the limbs with prestent reflux (n = 632) were divided into two groups. A segmental score of ≥3 indicated severe reflux and a score of <3 indicated moderate reflux. Of these 632 limbs, 161 (25%) had severe reflux and 471 (75%) had moderate reflux. The two groups demonstrated similar outcomes for most clinical parameters. The post-thrombotic limbs and nonthrombotic limbs also showed similar outcomes. ConclusionsThe long-term follow-up of patients after iliac vein stenting showed that uncorrected reflux is well tolerated by most patients across most clinical measures.

Effect of perioperative intravenous magnesium sulfate on postoperative pain after iliac venous stenting

BackgroundThe aim of the present study was to evaluate the effect of perioperative intravenous (IV) magnesium sulfate (MS) on low back pain (LBP) severity after iliac venous stent implantation. MethodsThe present study was a single-center retrospective study. A total of 97 patients who had undergone iliac venous stenting for post-thrombotic syndrome between January 1, 2019 and January 11, 2021 were considered for inclusion in the present study. The patients were divided into two groups: those who had received perioperative MS infusions (group M) and those who had not (control group; group C). Group M was given an IV bolus of 20 mg/kg before anesthesia induction and an IV MS infusion of 20 mg/kg/h during the procedure. Postoperative LBP severity was evaluated using the numerical rating scale at 1, 6, 12, and 24 hours after the procedure. The total tramadol consumption within 24 hours was measured with the help of a patient-controlled analgesia device. Moreover, additional analgesic needs and complaints of nausea and vomiting were evaluated. ResultsA total of 97 patients were considered for inclusion in the present study. Of the 97 patients, 29 were excluded because of a lack of follow-up data, leaving 68 patients for the final analysis (group M, n = 36; group C, n = 32). The demographic data, body mass index, sedation time, procedure time, and stented side data were similar between the two groups (P > .05). The rates of atropine and ephedrine use during the procedure were similar between the two groups (P > .05). The numerical rating scale scores were significantly lower for group M at all follow-up periods (P < .001). The total tramadol consumption at 24 hours postoperatively was 191.94 ± 68.194 mg for group M and 378.75 ± 31.367 mg for group C (P < .001). Additional analgesics were used by 8 patients (22.2%) in group M and 17 patients (53.1%) in group C. Additional analgesic needs were significantly lower for group M (P = .008). Nausea and vomiting were observed in six (19.4%) and four (11.1%) patients in group M and eight (32%) and five (15.6%) patients in group C, respectively (P > .05). ConclusionsFor patients undergoing iliac venous stenting, perioperative MS infusion was an effective and safe treatment option that reduced LBP severity, opioid consumption, and the need for additional analgesics in the acute postoperative period.

Venous Stenting After First Rib Resection: Is It Safe?

Venous stenting has been condemned for use prior to rib resection, based on the historical risk of stent fracture and poor long term outcomes.1 Recent series continue to show the risk of stent complications, up to 60% in a literature review by Schropp et al.2 However, a study by Rajendran in 2019 suggested acceptable secondary patency rates of 100% at two years, with primary patency of 55% in patients with recalcitrant lesions stented after decompression.3

Lower Limb Weakness due to Spinal Venous Congestion in Chronic Inferior Vena Cava Occlusion: A Case Report.

A 31 year-old male presented with a long history of reduced sensation and motor function in his lower limbs upon waking every morning, lasting 30-50 minutes during which he was unable to ambulate. He was involved in a severe road traffic accident as a child, and was born prematurely requiring prolonged neonatal hospitalisation. Both duplex ultrasonography and magnetic resonance venography identified an occlusion of the IVC, with patent common femoral and iliac veins draining into large spinal collaterals. No other cause was identified for his symptoms. After appropriate multidisciplinary team discussion and patient counselling, the patient proceeded to have endovenous recanalization of his IVC and common iliac veins with dedicated venous stents. Post-operatively, the patient reported an immediate resolution of neurological symptoms, with an improvement in quality of life questionnaire scores and with stent patency at 9-month follow up. IVC occlusion with symptomatic spinal venous congestion is a rare condition which may be successfully treated with endovascular iliocaval recanalization, although long-term outcomes of this treatment are still unknown.

Idiopathic Intracranial Hypertension from Benign to Fulminant: Diagnostic and Management Issues.

Idiopathic intracranial hypertension (IIH) primarrily affects obese women of childbearing years and is commonly associated with headaches, pulsatile tinnitus, and vision changes. Though most patients have a "benign" course, it can lead to significant morbidity, including blindness. The treatment approach is based on severity of visual impact and includes weight loss, intracranial pressure lowering medications, and sometimes surgery, such as spinal fluid diversion, optic nerve sheath fenestration, or venous sinus stenting. More studies are needed to determine when surgery is most appropriate and which surgical procedure provides maximal benefit with the least risk.

S2597 Gastrointestinal Hemorrhage From Hepaticojejunal Varices: A Rare Complication of Pancreaticoduodenectomy

Introduction: Ectopic varices are portosystemic collaterals that form outside the esophageal-gastric region and frequently pose a diagnostic and therapeutic challenge. Rarely, bleeding from ectopic varices can occur as a complication of pancreatic surgery. We describe a case of gastrointestinal bleeding from ectopic hepaticojejunal varices after pancreaticoduodenectomy. Case Description/Methods: A 66-year-old man with a history of intraductal papillary mucinous neoplasm (PMN) with high-grade dysplasia status post Whipple procedure two years previously, presented to the hospital with melena. His Whipple procedure had been complicated by splenic vein thrombosis and disease recurrence, necessitating further debridement three months prior to presentation. On examination, his vital signs were stable and there were no stigmata of liver disease. His laboratory tests were notable for a hemoglobin 8.0 g/dL (from baseline of 11 g/dL), platelets 174 × 109/L, BUN 29 mg/dL, INR 1.0. He initially underwent EGD and colonoscopy, which were unremarkable. A second look endoscopy was performed and deep intubation of the afferent limb revealed ectopic varices with stigmata of recent bleeding at the hepaticojejunostomy (Panel A). Cross-sectional imaging demonstrated a patent splenic vein but chronic occlusion of the portal and proximal superior mesenteric veins with cavernous transformation, extensive upper abdominal varices and splenomegaly (Panel B). There was no clinical or radiologic evidence of cirrhosis. After multidisciplinary discussion, an endovascular approach was deemed technically infeasible given extensive chronic mesenteric thrombus and a surgical approach was deemed prohibitively high-risk. The patient ultimately underwent endoscopic injection of 2-octyl cyanoacrylate into the ectopic varices and has remained without recurrent bleeding in over 5 months of follow-up. Discussion: Hemorrhage from ectopic jejunal varices following pancreatic surgery has previously been described in only a few case reports. Given the potential for vascular injury and local inflammation, these procedures can result in mesenteric venous thrombosis with subsequent ectopic variceal formation. If present, defining the vascular supply of varices with early multi-disciplinary involvement is paramount to their management. Multiple treatments have been reported, including portal venous stenting, embolization, and local sclerotherapy or cyanoacrylate injection as in this case.Figure 1.: (A) Ectopic varices (yellow arrows) are noted in the afferent limb at the hepaticojejunostomy. (B) Coronal view of computed tomography scan of abdomen demonstrating large upper abdominal collaterals (red arrow) that drain close to the afferent limb (white arrow).

Cerebral Venous Sinus Stenting for the Treatment of Idiopathic Intracranial Hypertension in a Child

AbstractIdiopathic intracranial hypertension (IIH) is a disease characterized by an increase in the opening pressure of the cerebrospinal fluid (CSF) associated with symptoms of elevated intracranial pressure (ICP). The condition is more prevalent in women and typically managed clinically. Surgical treatment is reserved for select refractory cases. The well-established surgical procedures for the management of IIH are CSF shunting and fenestration of the optic nerve sheath. These procedures, however, are associated with high rates of complication and recurrence.More recently, venous sinus angioplasty with stents has been employed in cases with documented narrowing of the sigmoid-transverse sinuses. This technique is associated with a significant reduction in the venous pressure gradient at the stenosis site, alleviating the symptoms of intracranial hypertension.We report a case of a previously healthy 12-year-old patient who presented with 10-day history of headaches, blurring of vision, nausea and vomiting, which evolved with worsening of the visual acuity and papilledema. Imaging scans disclosed stenosis of the right transverse and sigmoid sinuses. The patient underwent stenting of the stenotic venous segments and showed good evolution, with significant clinical improvement within 24 hours of the procedure.

Experimental study of a heparin-coated venous stent fabricated by atomic layer deposition.

To evaluate the safety and efficacy of heparin-coated venous stents in animals. We used atomic layer deposition technology to obtain a heparin coating with good stability and then prepared a heparin-coated venous stent based on this technology. The experimental stents were prepared according to the diameter of the rabbit inferior vena cava and were divided into Ni-Ti alloy stent group, Ni-Ti-Al2O3 stent group and Ni-Ti-Al2O3-Heparin stent group. 3 days, 7 days and 14 days after stent implantation, the materials were collected, and the three groups of stents were observed by hard tissue section pathology, immunohistochemistry and scanning electron microscope to observe the differences in vascular wall inflammation, thrombosis, lumen stenosis and vascular intima regeneration. The experiment confirmed the safety of the heparin-coated stent in vivo. Compared with the control group, the experimental group showed a high degree of vascular endothelialization and an intact neointimal structure 14 days after implantation. The long-term safety and biological effects of heparin-coated venous stents in animals require further study.

Clinical Utility of Routine Postprocedural Computed Tomography of the Head Following Elective Neuroendovascular Interventions

Little evidence supports acquisition of routine head imaging after uncomplicated elective neurosurgical procedures for patients with unchanged neurological examinations; however, imaging is still performed by some neurointerventionalists. We assessed the clinical utility of routine computed tomography of the head (CTH) following elective neuroendovascular interventions, including aneurysm coiling, aneurysm stent-assisted coiling, aneurysm flow diversion, arteriovenous malformation/fistula embolization, middle meningeal artery embolization for subdural hematoma, extracranial carotid artery stenting, and venous sinus stenting. Retrospective chart review identified patients undergoing neuroendovascular intervention from 2011 to 2021 at our institution. Demographic, clinical, and radiographic variables, including presenting signs and symptoms, antiplatelets and/or anticoagulant medications, intraprocedural complications, postprocedural CTH findings, and postprocedural neurological examinations, were recorded. Association of clinical variables with an abnormal postprocedural CTH was assessed with univariate analysis. Patients with ruptured vascular pathology, preoperative embolizations, and missing postprocedural CTH images and/or reports were excluded. Of 509 procedures identified, 354 were eligible for analysis; 4.8% of patients (17/354) had abnormal findings on postprocedural CTH. Nine patients had intraprocedural complications or new postprocedural neurological deficits that would have prompted imaging regardless of institutional practice. None of the remaining 8 (2.3%) patients required additional procedures. New postprocedural neurological deficit was the only significant predictor of abnormal postprocedural CTH (odds ratio= 6.79; 95% confidence interval, 2.01-20.32; P= 0.0009). In a large cohort of patients undergoing elective neuroendovascular intervention, no patients were identified for whom routine postprocedural CTH alone meaningfully altered their clinical care. Routine CTH is not necessary after uncomplicated elective neuroendovascular interventions performed with careful postprocedural neurological assessment.

A descriptive study of venous pressures and gradients while awake and both pre- and post-stent under anesthesia in patients with idiopathic intracranial hypertension

BackgroundThis study aims to explore factors that affect venous sinus pressures and associated gradients while awake and under general anesthesia (GA) both before and after venous sinus stenting (VSS) in...

Midterm and Long-Term Outcomes following Dedicated Endovenous Nitinol Stent Placement for Symptomatic Iliofemoral Venous Obstruction: Three- to 5-Year Results of the VIRTUS Study

PurposeTo assess the midterm patency and long-term safety of placement of a dedicated venous stent (Vici Venous Stent System) for the treatment of venous lesions of the iliofemoral outflow tract. Materials and MethodsPatients with unilateral obstructive disease of the iliofemoral veins and a Clinical, Etiological, Anatomical, Pathophysiological class of 3 or higher or a Venous Clinical Severity Score of 2 or greater were enrolled in this prospective, multicenter, single-arm study at 23 sites in the United States and Europe. The patients were followed up for 36 months after the index procedure for the assessment of patency and up to 60 months for the assessment of safety. The clinical outcomes in 11 patients with a stent fracture were assessed. ResultsA total of 200 patients enrolled in 2 cohorts (ie, feasibility cohort, n = 30; pivotal cohort, n = 170) were combined for this analysis. The overall 36-month primary patency rate was 71.7% (86/120), and the 36-month primary patency rate was 96.4% (27/28) for the nonthrombotic group and 64.1% (59/92) for the postthrombotic group. The freedom from major adverse events was 81.2% (53/65) through 60 months. The 60-month Kaplan-Meier estimate of freedom from target vessel revascularization (TVR) was 84.3%. In 9 of the 11 patients who had a stent fracture (1 patient with nonthrombotic etiology and 10 patients with postthrombotic etiology) identified at 12 months, the stents extended into the common femoral vein. The TVR rates and clinical outcomes were similar between patients with and without a stent fracture. ConclusionsThe results of the VIRTUS study demonstrated good midterm patency and long-term safety following the placement of a dedicated venous stent for iliofemoral obstruction.

A Comparison of Patient and Device Issues Reported for Recalled Venous Stent Systems

The first two Food and Drug Administration (FDA)-approved stents for treatment of iliofemoral vein obstruction, Boston Scientific's Vici and BD's Venovo venous stent systems, were both recalled in early 2021 within years of entering the market. Given the recent addition of patient issues as a publicly reported variable by the FDA Manufacturer and User Facility Device Experience (MAUDE) database, we set forth to analyze adverse event reports in MAUDE to better characterize issues reported for each system. MAUDE was queried for all adverse event reports for brands "Vici" and "Venovo" from their respective US FDA market approval dates to August 19, 2021. Reported device issues, patient issues, and interventions performed for each adverse event were compiled and compared using Fisher's exact test. A total of 50 unique adverse event reports were compiled for the Vici system and 341 for the Venovo system. The most common device issue reported for the Vici system was migration (48% vs. 0%; P=0.0001) versus activation failure in Venovo (85% vs. 4%; P=0.0001). A significantly higher proportion of Venovo reports specified no patient complications or symptoms (90% vs. 26%; P=0.0001), with no intervention performed (89% vs. 32%; P=0.001). A significantly higher proportion of Vici devices were extracted (8% vs. 2%; P=0.01), required use of a new device (26% vs. 5%; P=0.0001), and required application of a second stent within the venous stent initially placed (28% vs. 2%; P=0.0001). The rate of intervention with balloon expansion was not significantly different between the Vici and Venovo systems (6% vs. 2%; P=0.08). While 2 venous stent systems were recalled simultaneously, significant differences exist between reported device issues in MAUDE and whether patient injury was involved and well described. Our data suggest that despite recent improvements to MAUDE reporting, additional standardization with specificity regarding patient issues and interventions is needed to assist vascular surgeons monitoring real-time adverse event trends for vascular devices.

Assuring the Biofunctionalization of Silicone Covalently Bonded to Rhamnolipids: Antibiofilm Activity and Biocompatibility.

Silicone-based medical devices composed of polydimethylsiloxane (PDMS) are widely used all over the human body (e.g., urinary stents and catheters, central venous catheters stents) with extreme clinical success. Nevertheless, their abiotic surfaces, being prone to microorganism colonization, are often involved in infection occurrence. Improving PDMS antimicrobial properties by surface functionalization with biosurfactants to prevent related infections has been the goal of different works, but studies that mimic the clinical use of these novel surfaces are missing. This work aims at the biofunctional assessment of PDMS functionalized with rhamnolipids (RLs), using translational tests that more closely mimic the clinical microenvironment. Rhamnolipids were covalently bonded to PDMS, and the obtained surfaces were characterized by contact angle modification assessment, ATR-FTIR analysis and atomic force microscopy imaging. Moreover, a parallel flow chamber was used to assess the Staphylococcus aureus antibiofilm activity of the obtained surfaces under dynamic conditions, and an in vitro characterization with human dermal fibroblast cells in both direct and indirect characterization assays, along with an in vivo subcutaneous implantation assay in the translational rabbit model, was performed. A 1.2 log reduction in S. aureus biofilm was observed after 24 h under flow dynamic conditions. Additionally, functionalized PDMS lessened cell adhesion upon direct contact, while supporting a cytocompatible profile, within an indirect assay. The adequacy of the biological response was further validated upon in vivo subcutaneous tissue implantation. An important step was taken towards biofunctional assessment of RLs-functionalized PDMS, reinforcing their suitability for medical device usage and infection prevention.

Medium Term Outcomes of Deep Venous Stenting in the Management of Venous Thoracic Outlet Syndrome

Venous thoracic outlet syndrome (vTOS) is a relatively rare condition associated with significant morbidity. Its management continues to evolve, with increasing use of endovascular adjuncts, such as percutaneous thrombectomy and angioplasty, in addition to first rib resection. The utility of stenting residual venous stenotic lesions is poorly defined within the literature. This study sought to review the medium term patency rates of upper limb deep venous stenting in the management of vTOS. A single centre, retrospective review of patients managed for vTOS with first rib resection followed by upper limb deep venous stenting between January 2012 and February 2021 was conducted. Post-procedural ultrasounds were reviewed to determine stent patency. Twenty-six patients were included, with 33 stents placed. The median duration of follow up was 50 months. On venous duplex ultrasound at three years post-operatively, primary patency rates were 66%, primary assisted patency rates were 88%, secondary patency rates were 91%, and total occlusion rates were 9%. After stent placement, 80% of patients remained asymptomatic with regard to compression symptoms. Upper limb deep venous stenting is an effective adjunct to surgical decompression in the management of vTOS. Stent medium term patency rates are promising; however, further studies with longer follow up and larger cohorts with multicentre results are required to confirm these early findings.

Utilization of and Outcomes Associated with Intravascular Ultrasound during Deep Venous Stent Placement among Medicare Beneficiaries

PurposeTo evaluate temporal trends, practice variation, and associated outcomes with the use of intravascular ultrasound (US) during deep venous stent placement among Medicare beneficiaries. Materials and MethodsAll lower extremity deep venous stent placement procedures performed between January 1, 2017, and December 31, 2019 among Medicare beneficiaries were included. Temporal trends in intravascular US use were stratified by procedural setting and physician specialty. The primary outcome was a composite of 12-month all-cause mortality, all-cause hospitalization, or repeat target vessel intervention. The secondary outcome was a composite of 12-month stent thrombosis, embolization, or restenosis. ResultsAmong the 20,984 deep venous interventions performed during the study period, 15,184 (72.4%) utilized intravascular US. Moderate growth in intravascular US use was observed during the study period in all clinical settings. There was a variation in the use of intravascular US among all operators (median, 77.3% of cases; interquartile range, 20.0%–99.2%). In weighted analyses, intravascular US use during deep venous stent placement was associated with a lower risk of both the primary (adjusted hazard ratio, 0.72; 95% confidence interval [CI], 0.69–0.76; P < .001) and secondary (adjusted hazard ratio, 0.32; 95% CI, 0.27–0.39; P < .001) composite end points. ConclusionsIntravascular US is frequently used during deep venous stent placement among Medicare beneficiaries, with further increase in use from 2017 to 2019. The utilization of intravascular US as part of a procedural strategy was associated with a lower cumulative incidence of adverse outcomes after the procedure, including venous stent thrombosis and embolization.

Venous stent patency is independent of total stented length in nonthrombotic iliac vein and post-thrombotic venous stenoses

ObjectiveVenous stenting has become the preferred treatment of symptomatic outflow obstruction due to nonthrombotic iliac vein lesions (NIVLs) and post-thrombotic venous stenoses (PTs). A paucity of data exists regarding the effect of stent length on patency rates after intervention. We evaluated the association between stent length and patency in patients treated for iliofemoral venous outflow obstruction. MethodsThe institutional review board approved the present study. A total of 161 patients had undergone venous stenting for NIVLs and thrombotic disease from January 2016 to April 2021. For thrombotic disease, patients with PTs and those with acute deep vein thrombosis (DVT) with underlying outflow obstruction were included. The patient characteristics evaluated included gender, age, body mass index, diagnosed thrombophilia, a history of venous thromboembolism, and CEAP (clinical, etiologic, anatomic, pathophysiologic) score. All the patients had undergone multiplanar venography and intravascular ultrasound during the index procedure. The intravascular ultrasound findings were used to determine the diameter and length of the implanted stents. The patients were placed into two groups, those with stented lengths ≤100 mm and those with stented lengths >100 mm. The primary end point was stent patency between the two groups using duplex ultrasound at 6 months. ResultsA total of 108 patients (58.3% female) had had 6-month duplex ultrasound scans available for review. Their mean age was 55.6 ± 17.2 years. The mean body mass index was 31.7 ± 6.9 kg/m2. Overall, the 6-month patency was 89.9%. Of the 108 patients, 56 (51.9%) had had a total stented length of ≤100 mm with a 6-month patency of 92.9%. The remaining 52 patients (48.1%) had had a total stented length >100 mm with a 6-month patency of 86.5%. The rate of patency did not differ significantly between the two groups (P = .222). Stent patency at 6 months for patients with NIVLs was 98% (40 of 41). Stent patency for patients with PTs was 84% (32 of 38). Patency for patients with acute DVT who had undergone stenting after thrombectomy was 86% (25 of 29). Overall, 10 patients with thrombotic disease, including PT and acute DVT, had developed stent thrombosis. The total stented length was not predictive of the loss of patency. ConclusionsThese findings suggest that the length of stent coverage does not confer an increased likelihood of stent thrombosis for patients with iliofemoral venous obstruction. Interventionalists should treat the affected venous segments identified on intravascular ultrasound and effectively stent from normal to normal venous areas, regardless of the stent length required. These results suggest that the total stented length is not a risk factor for stent thrombosis for both NIVL and thrombotic iliofemoral venous lesions.