Outcomes of Venoplasty-Assisted,Peripherally Inserted Central Catheter Placement in Patients with Upper-Arm Venous Stenosis: Comparison with Midlines and Contralateral Placement

PurposeTo compare the effectiveness and safety of percutaneous transluminal angioplasty and peripherally inserted central catheter (PTA + PICC), contralateral PICC, and midline catheterization (MC) in patients with venous stenosis.Materials and MethodsA total of 7,327 PICC procedures were performed in 5,421 patients at a single institution between 2013 and 2019. Among them, 87 patients had upper-arm venous stenoses and were managed with PTA + PICC, contralateral PICC, or MC. Data on catheter-dwell time, clinical success rate, and adverse events were recorded. The procedure was considered to have clinically succeeded when a PICC was removed from the patient just before discharge or after the completion of therapy. Catheter survival time and the chance of adverse events were compared among the groups using the Kaplan-Meier method and log-rank test.ResultsPTA + PICC, contralateral PICC, and MC procedures were performed for 57 (65.5%, 57/87), 10 (11.5%, 10/87), and 20 (23.0%, 23/87) patients, respectively. The mean catheter-dwell time in the PTA + PICC, contralateral PICC, and MC groups was 49.7, 28.7, and 15.1 days, respectively, and the clinical success rate of each group was 86.0% (49/57), 80.0% (8/10), and 50.0% (10/20). The PTA + PICC group had a significantly longer catheter survival time than the MC group (P < .001). The chance of a catheter-related infection (P = .008) was significantly lower in the PTA + PICC group than in the MC group.ConclusionsPTA + PICC or contralateral PICC should be considered prior to ipsilateral MC when venous stenosis is encountered during PICC procedures.     

Value Improvement by Assessing IR Care via Time-Driven Activity-Based Costing

PurposeTo evaluate time-driven activity-based costing (TDABC) in interventional radiology for image-guided vascular malformation treatment as an example.Materials and MethodsRetrospective analysis was performed on consecutive vascular malformation treatment cycles [67 venous malformations (VMs) and 11 arteriovenous malformations (AVMs)] in a university hospital in 2018. All activities were integrated with a process map, and spent resources were assigned accordingly. TDABC uses 2 parameters: (i) practical capacity cost rate, calculated as 80% of theoretical capacity, and (ii) time consumption of each resource determined by interviews (23 items). Thereby, the total costs were calculated. Treatment cycles were modified according to identified resource waste and TDABC-guided negotiations with health insurance.ResultsTotal personnel time required was higher for AVM (1,191 min) than for VM (637 min) treatment. The interventional procedure comprised the major part (46%) of personnel time required in AVM, whereas it comprised 19% in VM treatment. Materials represented the major cost type in AVM (75%) and VM (45%) treatments. TDABC-based treatment process modification led to a decrease in personnel time need of 16% and 30% and a cost reduction of 5.5% and 15.7% for AVM and VM treatments, respectively. TDABC-guided cost reduction and TDABC-informed negotiations improved profit from ?56% to +40% and from +41% to +69% for AVM and VM treatments, respectively.ConclusionsTDABC facilitated the precise costing of interventional radiologic treatment cycles and optimized internal processes, cost reduction, and revenues. Hence, TDABC is a promising tool to determine the denominator of interventional radiology's value.     

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

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

Cost Burden and Cost Influencers of Inferior Vena Cava Filter Placement and Retrieval among Medicare Beneficiaries with Acute Venous Thromboembolism

PurposeTo examine the frequency, costs, and cost influencers of inferior vena cava filters (IVCFs) placements and retrievals among a national sample of patients using Medicare data.Materials and MethodsThis retrospective cohort study used the U.S. Medicare 100% database, a nationally representative sample of all U.S. patients aged ≥65 years, from 2014 through 2020. Procedures and clinical characteristics were identified from the diagnosis and procedure codes on Medicare claims. Beneficiaries aged ≥65 years with newly diagnosed venous thromboembolism (VTE) were identified and followed to obtain data on IVCF placements and retrievals. Data on the costs of the index IVCF procedures and any subsequent IVCF placements and retrievals were obtained. Multivariate models were used to estimate the impact of patient and clinical characteristics on costs.ResultsAmong 501,216 patients with newly diagnosed VTE, 4,995 (1%) received an IVCF placement; of these, 1,215 (24.3%) had a retrieval procedure. Beneficiaries with IVCF placements and retrievals differed from a demographic and clinical perspective than from those without. Costs varied by the site of service, VTE acuity, and VTE type. Cost influencers included age, race, census region, service location, and VTE type.ConclusionsIVCF placement costs were driven by baseline patient characteristics (age, race, geographic residence, acute VTE diagnosis, and inpatient site of service), whereas retrieval costs were driven by age and deep vein thrombosis diagnosis. Strategies to mitigate the retrieval costs or the need to retrieve IVCFs may reduce the overall cost burden of IVCFs.     

Cost-Effectiveness of a Guided Peripherally Inserted Central Catheter Placement System: A Single-Center Cohort Study

PurposeTo assess the cost-effectiveness of peripherally inserted central catheter (PICC) placements using an ultrasound and electrocardiogram-guided system versus external measurements and confirmatory chest X-rays (CXRs).Materials and MethodsSixty-eight guided PICC placements were performed in 63 outpatients (mean age, 43 ± 13 years; 50% male) and compared to 68 propensity score-matched PICC placements (mean age, 44 ± 13 years; 56% male) performed using external measurements by the same operators. Post-placement CXRs were used to confirm final catheter tip positioning. Cohorts were compared in terms of repositioning rates, desired tip positioning rates (in the lower third of the superior vena cava or at the cavoatrial junction), and estimated cost per PICC positioned as desired using manufacturer quotes, Medicare reimbursement rates, and hourly wages for staff time. Agreement between tip positioning according to the guided system versus CXR was also assessed.ResultsGuided PICC placements required less repositioning (1.5% vs 10.3%, P = .03) and resulted in more catheters positioned as desired (86.8% vs 67.6%, P = .01) than the external measurement approach. The cost per PICC positioned as desired was lower for guided placements ($318.54 vs $381.44), suggesting that the guided system was cost-effective in this clinical setting. Guided system-CXR agreement for tip position was poor (κ=0.25, P = .002) due to tips being slightly farther from the cavoatrial junction on CXR than indicated by the guided system.ConclusionsThe guided PICC placement system was cost-effective in outpatients treated by a single division of interventional radiology at an academic institution.     

Multicenter Experience with the Surfacer Inside-Out Access Catheter System in Patients with Thoracic Venous Obstruction: Results from the SAVE Registry

PurposeTo report the device performance and safety for the Surfacer Inside-Out access catheter system in patients with thoracic central venous obstruction (TCVO) requiring central venous access (CVA).Materials and MethodsFive sites prospectively enrolled 30 patients requiring a tunneled dialysis catheter between February 2017 and September 2018 in the SAVE (Surfacer System to Facilitate Access in Venous Obstructions) registry. Patient demographics, medical history, and type of TCVO were documented at enrollment. Device performance and adverse events were collected during the procedure and upon hospital discharge. Twenty-nine of the 30 patients enrolled required CVA for hemodialysis. Retrospective classification of TCVOs according to SIR reporting standards showed 9 patients (30%) had Type 4 obstructions, 8 (26.7%) had Type 3, 5 (16.7%) had Type 2, and 8 (26.7%) had Type 1 obstruction.ResultsCentral venous catheters (CVCs) were successfully placed in 29 of 30 patients (96.7%). The procedure was discontinued in 1 patient due to vascular anatomical tortuosity. All 29 patients with successful CVC placement achieved adequate catheter patency and tip positioning. There were no device-related adverse events, catheter malposition, or intra- or postprocedural complications. Mean time from device insertion to removal for the 29 patients who successfully completed the procedure was 24 ± 14.9 (range, 6–70) minutes. Mean fluoroscopy time was 6.8 ± 4.5 (range, 2.2–25.5) minutes.ConclusionsThe Surfacer Inside-Out procedure provided an alternative option to restore right-sided CVA in patients with TCVO.     

Spontaneous Dislodgement of Tunneled Dialysis Catheters after De Novo versus Over-The-Wire-Exchange Placement

PurposeTo evaluate dislodgement of tunneled dialysis catheters (TDCs) in de novo (DN) placement with ultrasound versus over-the-wire exchange (OTWE).Materials and MethodsData were collected retrospectively on all TDC placements at this institution from 2001 to 2019 and were excluded if no removal date was recorded or if dwell time was more than 365 days. Information on TDC brand, placement, insertion/removal, and removal reason were collected. Multiple logistic regression evaluated factors associated with TDC dislodgement. DN placement and OTWE were compared for rate of dislodgement (generalized estimating equations method) and TDC dwell time (survival analysis).ResultsIn total, 5328 TDCs were included with 66% (3522) placed DN and 32% (1727) via OTWE. Mean dwell time was 65 ± 72 days, and dislodgement occurred in 4% (224). TDC dislodgement rates in the DN and OTWE groups were 0.48 and 0.93 per 1000 catheter days, respectively. Brand (Ash Split vs. VectorFlow), placement technique (OTWE vs. DN), laterality (left vs. right), and site (left vs. right internal jugular vein) were significant predictors of dislodgement. OTWE placement exhibited 1.7 times the odds of dislodgement (95% confidence interval, 1.2–2.6; P = .004) compared to DN and had significantly higher probability of dislodgement across time (hazard ratio = 2.0; P < .001) compared to DN. Dislodgement rates for OTWE vs. DN were 8% vs. 3% (3 months), 13% vs. 6% (6 months), and 38% vs. 17% (1 year).ConclusionsTDC spontaneous dislodgement rates were significantly and consistently higher after OTWE compared to DN placement. These data support more careful attention to catheter fixation after OTWE placement.     

Research Consensus Panel Follow-Up: A Systematic Review and Update on Cost Research in IR

PurposeTo systematically review cost research in interventional radiology (IR) published since the Society of Interventional Radiology Research Consensus Panel on Cost in December 2016.Materials and MethodsA retrospective assessment of cost research in adult and pediatric IR since December 2016 to July 2022 was conducted. All cost methodologies, service lines, and IR modalities were screened. Analyses were reported in a standardized fashion to include service lines, comparators, cost variables, analytical processes, and databases used.ResultsThere were 62 studies published, with most from the United States (58%). Incremental cost-effectiveness ratio, quality-adjusted life-years, and time-driven activity-based costing (TDABC) analyses were performed in 50%, 48%, and 10%, respectively. The most frequently reported service line was interventional oncology (21%). No studies on venous thromboembolism, biliary, or IR endocrine therapies were found. Cost reporting was heterogeneous owing to varying cost variables, databases, time horizons, and willingness-to-pay (WTP) thresholds. IR therapies were more cost-effective than their non-IR counterparts for treating hepatocellular carcinoma ($55,925 vs $211,286), renal tumors ($12,435 vs $19,399), benign prostatic hyperplasia ($6,464 vs $9,221), uterine fibroids ($3,772 vs $6,318), subarachnoid hemorrhage ($1,923 vs $4,343), and stroke ($551,159 vs $577,181). TDABC identified disposable costs contributing most to total IR costs: thoracic duct embolization (68%), ablation (42%), chemoembolization (30%), radioembolization (80%), and venous malformations (75%).ConclusionsAlthough much of the contemporary cost-based research in IR aligned with the recommendations by the Research Consensus Panel, gaps remained in service lines, standardization of methodology, and addressing high disposable costs. Future steps include tailoring WTP thresholds to nation and health systems, cost-effective pricing for disposables, and standardizing cost sourcing methodology.     

Comparison of Anticoagulation Regimens Following Stent Placement for Nonthrombotic Lower Extremity Venous Disease

PurposeTo determine whether subtherapeutic anticoagulation regimens are noninferior to therapeutic anticoagulation regimens following stent placement for nonthrombotic lower extremity venous disease.Materials and MethodsFifty-one consecutive patients (88% women; mean age, 44 years) who underwent stent placement for nonthrombotic lower extremity venous disease between 2002 and 2016 were retrospectively identified. The patients were divided into 2 cohorts: those who received prophylactic enoxaparin or no anticoagulation (subtherapeutic) after the procedure and those who received therapeutic doses of anticoagulation with enoxaparin, warfarin, and/or rivaroxaban (therapeutic) after the procedure. Baseline demographic characteristics, procedure characteristics, and outcomes were compared between the 2 groups using the Student t test, Fisher exact test, and χ² test. The subtherapeutic and therapeutic anticoagulation groups did not differ significantly in the baseline demographic characteristics (eg, sex, race, and age) or procedure characteristics (eg, number of stents placed, stent brand, stent diameter, etc).ResultsThe mean clinical follow-up time was 4.4 years (range, 0–16.3 years). There were no thrombotic adverse events or luminal obstructions due to in-stent restenosis in either group. There were 5 minor bleeding adverse effects in the therapeutic group and no bleeding adverse effects in the subtherapeutic group (P = .051). There were no statistically significant differences in subjective symptom improvement (P = .75).ConclusionsIn this retrospective cohort, the subtherapeutic and therapeutic anticoagulation regimens produced equivalent outcomes in terms of adverse event rates, reintervention rates, and symptomatic improvement, suggesting that therapeutic doses of anticoagulation do not improve outcomes compared with subtherapeutic anticoagulation regimens following nonthrombotic venous stent placement.     

Comparison between Antegrade versus Retrograde Ureteral Stent Placement for Malignant Ureteral Obstruction

PurposeTo compare the technical success of antegrade uteral stent (AUS) and retrograde ureteral stent (RUS) placements in patients with malignant ureteral obstruction (MUO) and to determine the predictors of technical failure of RUS.Materials and MethodsThis study retrospectively included 61 AUS placements (44 patients) performed under fluoroscopic guidance and 76 RUS placements (55 patients) performed under cystoscopic guidance in patients with MUO from January 2019 to December 2020. Technical success rates of the 2 techniques were compared using inverse probability of treatment weighting (IPTW) analysis. Logistic regression was used to identify predictive factors for technical failures.ResultsTechnical success was achieved in 98.4% of the AUS group and 47.4% of the RUS group. After stabilized IPTW, the technical success rate was higher in the AUS group than in the RUS group (adjusted risk difference, 49.4%; 95% confidence interval [CI], 35.4%–63.1%). The independent predictors for technical failure of the RUS procedure were age of ≥65 years (odds ratio [OR], 5.56; 95% CI, 1.73–21.27), ureteral orifice invasion (OR, 4.21; 95% CI, 1.46–13.46), and extrinsic cancer (OR, 15.58; 95% CI, 2.92–111.81).ConclusionsThe technical success rate of AUS placement was higher than that of RUS placement in patients with MUO. RUS failure was associated with age of ≥65 years, cancer with ureteral orifice invasion, and extrinsic ureteral obstruction.     

Venous Biomechanics of Angioplasty and Stent Placement: Implications of the Poisson Effect

PurposeTo characterize the Poisson effect in response to angioplasty and stent placement in veins and identify potential implications for guiding future venous-specific device design.Materials and MethodsIn vivo angioplasty and stent placement were performed in 3 adult swine by using an established venous stenosis model. Iron particle endothelium labeling was performed for real-time fluoroscopic tracking of the vessel wall during intervention. A finite-element computational model of a vessel was created with ADINA software (version 9.5) with arterial and venous biomechanical properties obtained from the literature to compare the response to radial expansion.ResultsIn vivo angioplasty and stent placement in a venous stenosis animal model with iron particle endothelium labeling demonstrated longitudinal foreshortening that correlated with distance from the center of the balloon (R² = 0.87) as well as adjacent segment narrowing that correlated with the increase in diameter of the treated stenotic segment (R² = 0.89). Finite-element computational analysis demonstrated increased Poisson effect in veins relative to arteries (linear regression coefficient slope comparison, arterial slope 0.033, R² = 0.9789; venous slope 0.204, R² = 0.9975; P < .0001) as a result of greater longitudinal Young modulus in veins compared with arteries.ConclusionsClinically observed adjacent segment narrowing during venous angioplasty and stent placement is a result of the Poisson effect, with redistribution of radially applied force to the longitudinal direction. The Poisson effect is increased in veins relative to arteries as a result of unique venous biomechanical properties, which may be relevant to consider in the design of future venous interventional devices.     

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.     

High-Suspicion Subcentimeter Thyroid Nodules: Cost Effectiveness of Active Surveillance versus Fine Needle Aspiration

PurposeTo compare the cost-benefit of active surveillance (AS) against immediate fine needle aspiration (FNA) of sonographically suspicious subcentimeter thyroid nodules.Materials and MethodsA Markov model was constructed to compare the cost-benefit of 3 strategies from the point of discovery until death: (a) Surveillance of all nodules, (b) Surveillance of nodules with positive cytology, and (c) Surgery of nodules with positive cytology. The reference case was a 40-year-old woman with a sonographically suspicious subcentimeter thyroid nodule. Transition probabilities, costs, and health state utilities were derived from the literature. Sensitivity analyses were performed to evaluate model uncertainty. Willingness-to-pay threshold was set at $100,000/quality-adjusted life year.ResultsSurveillance of nodules with positive cytology dominated in the reference scenario and was cost-beneficial over Surveillance of all nodules, independent of the utility of AS. Surveillance of all nodules was cost-beneficial only at a life expectancy of <2.6 years or surveillance duration of <4 years.ConclusionsWhile current guidelines recommend AS of sonographically suspicious subcentimeter nodules, the results of this study suggest that immediate FNA (Surveillance of nodules with positive cytology) is more cost-beneficial than AS (Surveillance of all nodules). Patients with positive cytology on FNA may subsequently opt for AS (Surveillance of nodules with positive cytology) or surgery (Surgery of nodules with positive cytology) according to their level of comfort (ie, utility) with AS.     

Interventional Radiologists Achieve Equivalent Outcomes and Lower Costs for Totally Implantable Venous Access Device Placement Compared to Operating Room Placement

PurposeTo compare the cost and outcomes of surgical and interventional radiology (IR) placement of totally implantable venous access devices (TIVADs) within a large regional health system to determine the service line with better outcomes and lower costs to the health system.Materials and MethodsA retrospective review of all chest port placements performed in the operating room (OR) and IR suite over 12 months was conducted at a large, integrated health system with 6 major hospitals. Secondary electronic health record and cost data were used to identify TIVAD placements, follow-up procedures indicating port malfunction, early adverse events (within 1 month after the surgery), late adverse events (2–12 months after the procedure), and health system cost of TIVAD placement and management.ResultsFor 799 total port placements included in this analysis, the rate of major adverse events was 1.3% and 1.9% for the IR and OR groups, respectively, during the early follow-up (P = .5655) and 4.9% and 2.8% for the IR and OR groups, respectively, during the late follow-up (P = .5437). Malfunction-related follow-up procedure rates were 1.8% and 2.6% for the IR and OR groups, respectively, during the early follow-up (P = .4787) and 12.4% and 10.5% for the IR and OR groups, respectively, during the late follow-up (P = .4354). The mean cost of port placement per patient was $4,509 and $5,247 for the IR and OR groups, respectively. The difference in per-patient cost of port placement was $1,170 greater for the OR group (P = .0074).ConclusionsThe similar rates of adverse events and follow-up procedures and significant differences in insertion cost suggest that IR TIVAD placement may be more cost effective than surgical placement without affecting the quality.     

Dural Venous Sinus Stent Placement Reduces Dosage Requirements for Carbonic Anhydrase Inhibitors in Patients with Idiopathic Intracranial Hypertension

This retrospective single-center study evaluated the change in required dosage of acetazolamide and topiramate before and after dural venous sinus stent placement (VSSP) for idiopathic intracranial hypertension (IIH). Adults diagnosed with IIH who failed optimized medical management and were treated with VSSP were included. This study comprised 55 patients who underwent VSSP for the diagnosis of IIH. The median preprocedural dosage of acetazolamide and topiramate was 1,000 mg (range, 500–4,000 mg) and 100 mg (range, 0–200 mg), respectively, among patients able to tolerate the medications. The median postprocedural dosage of acetazolamide and topiramate was 375 mg (range, 0–4,000 mg), with a mean reduction of 52.9% (P = .001), and 0 mg (range, 0–200 mg), with a mean reduction of 45.9% (P = .005), respectively. Dural VSSP significantly reduced dosage requirements for acetazolamide and/or topiramate, potentially reducing the morbidity secondary to medication side effects.     

Comparison of Fibered versus Nonfibered Coils for Venous Embolization in an Ovine Model

PurposeTo compare nylon fibered (F) with nonfibered (NF) coils for embolization in an ovine venous model.Materials and MethodsFour- to 8-mm-diameter, 0.035-inch F and NF coils were deployed in 24 veins in 6 sheep. The number of coils, total length of the coils, and length of implanted coil pack required to achieve complete stasis were recorded, as were vessel diameter, radiation dose, ease of packing, damage to embolized vessel, and time to stasis. Venography at 1 and 3 months was used to assess the migration and durability of vessel occlusion. Veins were harvested at 3 months.ResultsF and NF coils were deployed in 24 veins, and stasis was achieved, without immediate coil migration or vessel damage. The mean numbers of F and NF coils per vein were 5 and 8.75, respectively (P = .007). The vessel diameter between the groups was not statistically different. The total coil length (F, 70 cm vs NF, 122.5 cm; P = .0007), coil pack length (F, 29.3 mm vs NF, 39.4 mm; P = .003), time to stasis (F, 5.3 minutes vs NF, 9.0 minutes; P = .008), and radiation dose (F, 25.3 mGy vs NF, 34.9 mGy; P = .037) were significantly different between the groups. Challenges with the animal model prevented conclusive long-term results. Migration occurred with 8 of 11 (72%) coil packs in the femoral veins and 0 of 13 (0%) coil packs in the internal iliac and deep femoral veins. Venography demonstrated that of 16 remaining coil packs, 11 were occluded at 1 month and 10 remained occluded at 3 months.ConclusionsFibers allow for significantly fewer coils to achieve immediate venous occlusion.     

Hemodialysis Catheters in Infants: A Retrospective Single-Center Cohort Study

PurposeEvaluate technical aspects and outcomes of insertion/maintenance of hemodialysis (HD) central venous catheter (CVC) during infancy.Materials and MethodsSingle-center retrospective study of 29 infants who underwent 49 HD-CVC insertions between 2002 and 2016. Demographics, procedural, and post-procedural details, interventional radiology (IR) maintenance procedures, technical modifications, complications, and outcomes were evaluated. Technical adjustments during HD-CVC placement to adapt catheter length to patient size were labeled “modifications.” CVCs requiring return visit to IR were called IR-maintenance procedures. Mean age and weight at HD-CVC insertion were 117 days and 4.9 kg.ResultsOf the 29 patients, 13 (45%) required renal-replacement-therapy (RRT) as neonates, 10 (34%) commenced RRT with peritoneal dialysis (PD), and 19 (66%) with HD. Fifteen nontunneled and 34 tunneled HD-CVCs were inserted while patients were ≤1 year. Technical modifications were required placing 25/49 (51%) HD-CVCs: 5/15 (33%) nontunneled and 20/34 (59%) tunneled catheters (P = .08). Patients underwent ≤6 dialysis-cycles/patient during infancy (mean 2.3), and a mean of 4.1 and 49 HD-sessions/catheter for nontunneled and tunneled HD-CVCs, respectively. Mean primary and secondary device service, and total access site intervals for tunneled HD-CVCs were 75, 115, and 201 days, respectively. A total of 26 of 49 (53%) patients required IR-maintenance procedures. Nontunneled lines had greater catheter-related bloodstream infections per 1,000 catheter-days than tunneled HD-CVCs (9.25 vs. 0.85/1,000 catheter days; P = .02). Nineteen patients (65%) survived over 1 year. At final evaluation (December 2017): 8/19 survived transplantation, 5/19 remained on RRT, 2/19 completely recovered, 1/19 lost to follow-up, and 3 died at 1.3, 2, and 10 years.ConclusionsPlacement/maintenance of HD-CVCs in infants pose specific challenges, requiring insertion modifications, and IR-maintenance procedures to maintain function.     

Cryoablation of Venous Malformations: A Systematic Review

This study aimed to review systematically the efficacy, safety, and technical aspects of cryoablation in the treatment of venous malformations (VMs) and to provide the groundwork for future studies. A literature search for clinical studies utilizing percutaneous cryoablation of VMs was performed. All clinical studies related to primary or secondary treatment of VMs with percutaneous cryoablation were included in this review. These selected studies were evaluated for patient characteristics, cryoablation technique, technical success, lesion size and pain scores before and after cryoablation, and adverse outcomes. Random effects analysis of postprocedural changes in lesion volume and pain scores was performed. There were 54 patients with 55 cases of cryoablation of VMs. Of these cases, 27 recorded changes in lesion volume and 31 recorded changes in pain scores. The weighted mean postprocedural decrease in lesion size was 92.0% (raw average, 71.7%). The weighted mean reduction in pain score was 77% (raw average, 78.2%). Considering all treated cases (55), complete resolution of symptoms was seen in 35 cases (63.6%) and overall (complete or partial) improvement in 52 cases (94.5%). Common postprocedural symptoms included pain, bruising, swelling and numbness lasting less than 2 weeks. There were two major adverse events (3.7%), with both cases due to persistent dysesthesia. Patients with a history of prior sclerotherapy demonstrated lower preprocedural and postprocedural pain scores (4.7 and 1.3) than patients without prior treatments (5.8 and 2.8). Cryoablation of VMs appears to be potentially safe and effective on limited short-interval follow-up.     

Length of Stay Predicts Risk of Early Infection for Hospitalized Patients Undergoing Central Venous Port Placement

PurposeTo compare early totally implantable central venous port catheter–related infection rates after inpatient vs outpatient placement and to determine whether the risk associated with inpatient placement is influenced by length of hospital stay.Materials and MethodsIn this single-institution retrospective study, 5,301 patients (3,618 women; mean age 57 y) underwent port placement by interventional radiologists between October 2004 and January 2018. The 30-day infection rate was compared between inpatients and outpatients using survival analysis. Among inpatients, the effect of time from admission to port placement and from placement to discharge was analyzed using a survival regression tree.ResultsThe 30-day infection rate was 3.6% (95% confidence interval [CI] = 1.9%–6.1%) among 386 inpatients and 1.0% (95% CI = 0.7%–1.3%) among 4,915 outpatients (hazard ratio [HR] = 3.6, 95% CI = 2.0–6.6, P < .001). Inpatient placement was a significant risk factor after accounting for covariates in multivariate analysis (HR = 2.2, 95% CI = 1.0–4.7, P = .05) and controlling for demographic differences by propensity score matching (HR = 2.8, 95% CI = 1.0–7.8, P = .04). Infection rate was 11% (95% CI = 4.7%–22%) among 65 inpatients in whom time from admission to placement was ≥ 7 days, 5.1% (95% CI = 1.9%–11%) among 129 inpatients in whom admission to placement was < 7 days and time to discharge was > 3 days, and 0% (95% CI = 0%–2.1%) among 192 inpatients in whom admission to placement was < 7 days and time to discharge was ≤ 3 days (P < .001).ConclusionsInpatient port placement was associated with a higher risk of early infection. However, a clinical decision tree based on shorter length of stay before and after placement may identify a subset of hospitalized patients not at increased risk for infection.     

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.