Vessel Occlusion using Hydrogel-Coated versus Nonhydrogel Embolization Coils in Peripheral Arterial Applications: A Prospective,Multicenter, Randomized Trial

PurposeTo evaluate the safety and effectiveness of hydrogel-coated coils for vessel occlusion in the body trunk.Materials and MethodsA total of 77 patients with various peripheral vascular lesions, treatable by embolization with coils, were randomized (hydrogel group, n = 38; nonhydrogel group, n = 39). In the hydrogel group, embolization of the target vessel was conducted using 0.018-inch hydrogel-coated coils (AZUR 18; Terumo Medical Corporation, Tokyo, Japan) with or without bare platinum coils. The nonhydrogel group received both bare platinum coils and fibered coils without the use of hydrogel-coated coils.ResultsComplete target vessel occlusion was accomplished in 36 patients in the hydrogel group and 37 patients in the nonhydrogel group. No major adverse events were observed in either group. The median number of coils/vessel diameter and the median total coil length/vessel diameter were significantly larger in the nonhydrogel group than in the hydrogel group (P = .005 and P = .004, respectively). The median embolization length was significantly longer in the nonhydrogel group (31.95 mm) than in the hydrogel group (23.43 mm) (P = .002). If no expansion was assumed, the median packing density in the hydrogel group was 44.9%, which was similar to that in the nonhydrogel group (46.5%) (P = .79). With full expansion assumed, the median packing density in the hydrogel group was 125.7%.ConclusionsHydrogel-coated coils can be safely used for peripheral vascular coil embolization, and hydrogel-coated and conventional coils in combination allow for a shorter embolization segment and shorter coil length.     

Predictors of Occlusion of Hepatic Blood Vessels after Irreversible Electroporation of Liver Tumors

PurposeTo examine predictors of midterm occlusion in portal and hepatic veins within or adjacent to the ablation zone after irreversible electroporation (IRE) of liver tumors.Materials and MethodsThis retrospective cohort analysis included 39 patients who underwent CT-guided IRE of liver tumors. Vessels within or adjacent to the ablation zone were identified on CT images acquired immediately after the procedure, and the positional relationships with the ablation zone (within/adjacent), locations (proximal/distal), and diameters (< 4 mm or ≥ 4 mm) were evaluated. Using contrast-enhanced follow-up scans, each vessel was classified as patent, stenosed, or occluded. Associations between vessel occlusion and each variable were investigated.ResultsOverall, 33 portal veins and 64 hepatic veins were analyzed. Follow-up scans showed occlusion in 12/33 (36.7%) portal veins and 17/64 (26.6%) hepatic veins. Vessels within the ablation zone were occluded significantly more frequently than vessels adjacent to the ablation zone (portal: 55.6% [10/18] vs 13.3% [2/15], P = .04; hepatic: 45.4% [15/33] vs 6.4% [2/31], P = .011). Vessels with a diameter < 4 mm were also occluded significantly more frequently than vessels with a diameter ≥ 4 mm (portal: 72.7% [8/11] vs 18.1% [4/22], P = .011; hepatic: 54.8% [17/31] vs 0% [0/33], P < .001). The respective positive and negative predictive values for occlusion of vessels categorized as both within and < 4 mm were 88% (7/8) and 82% (20/25) for portal veins and 79% (15/19) and 96% (43/45) for hepatic veins.ConclusionsMidterm vessel occlusion after liver IRE could be predicted with relatively high accuracy by assessing ablation location and vessel diameter.     

Safety Profile of Particle Embolization for Treatment of Acute Lower Gastrointestinal Bleeding

PurposeTo assess ischemic adverse events following particle embolization when used as a second-line embolic to coil embolization for the treatment of acute lower gastrointestinal bleeding (LGIB).Materials and MethodsThe single-institution retrospective study examined 154 procedures where embolization was attempted for LGIB. In 122 patients (64 men; mean age, 69.9 years), embolization was successfully performed using microcoils in 73 procedures, particles in 34 procedures, and both microcoils and particles in 27 procedures. Particles were used as second-line only when coil embolization was infeasible or inadequate. Technical success was defined as angiographic cessation of active extravasation after embolization. Clinical success was defined as the absence of recurrent bleeding within 30 days of embolization.ResultsTechnical success for embolization of LGIB was achieved in 87% of the cases (134/154); clinical success rate was 76.1% (102/134) among the technically successful cases. Clinical success was 82.2% (60/73) for coils alone and 68.9% (42/61) for particles with or without coils. Severe adverse events involving embolization-induced bowel ischemia occurred in 3 of 56 (5.3%) patients who underwent particle embolization with or without coils versus zero of 66 patients when coils alone were used (P = .09). In patients who had colonoscopy or bowel resection within 2 weeks of embolization, ischemic findings attributable to the procedure were found in 3 of the 15 who underwent embolization with coils alone versus 8 of 18 who underwent embolization with particles with or without coils (P = .27).ConclusionsParticle embolization for the treatment of LGIB as second-line to coil embolization was associated with a 68.9% clinical success rate and a 5.3% rate of ischemia-related adverse events.     

Analyzing Radiation Use during Transjugular Intrahepatic Portosystemic Shunt Creation

Portal vein access during transjugular intrahepatic portosystemic shunt creation was examined in 11 patients. Radiation metrics (kerma area product, reference point air kerma, and fluoroscopy times) during portal vein access were significantly greater for conventional versus intravascular US–guided transjugular intrahepatic portosystemic shunt (54.8 mGy ∙ cm² ± 27.6 vs 8.4 mGy ∙ cm² ± 5.0, P = .009; 210.4 mGy ± 109.1 vs 29.5 mGy ± 18.4, P = .009; 19.1 min ± 8.6 vs 8.9 min ± 4.6, P = .04). Wedged hepatic venography is a major contributor to radiation exposure. Intravascular US guidance is associated with significantly reduced radiation use.     

Pathological Analysis of Vascularization of the Arterialized Veins in Failed Arteriovenous Fistulae

PurposeTo assess venous wall vascularization and its correlation with neointimal hyperplasia (NIH) in failed arteriovenous fistulae (AVFs).Materials and MethodsA total of 43 uremic patients who underwent de novo AVF creation and 39 patients who underwent reconstruction of failed fistulae were enrolled in the study. A 5–10-mm vein segment adjacent to the future fistula creation or reconstruction site was surgically removed and assessed using histopathological analyses and stained by immunohistochemistry to quantify vasa vasorum density (VVD).ResultsBoth the intimal thickness (70.68 [28.81–99.54] vs 4.53 [2.69–7.30] μm, P < .001) and the intimal thickness-to-medial thickness ratio (2.20 [0.77–4.36] vs 0.15 [0.10–0.30], P < .001) were higher in failed AVFs than in preaccess veins. CD31- and factor VIII–marked VVDs in both the intima (6.31 [1.62–12.53] vs 0.0 [0.0–0.0], P < .001; 7.82 [3.33–11.61] vs 0.0 [0.0–0.0], P < .001) and media (10.0 [7.59–12.95] vs 3.71 [2.44–4.87], P < .001; 8.33 [5.55–13.0] vs 3.57 [2.53–4.82], P < .001) as well as the intimal VVD:medial VVD ratio (0.67 [0.19–1.08] vs 0.0 [0.0–0.0], P < .001; 0.71 [0.39–1.14] vs 0.0 [0.0–0.0], P < .001) were significantly higher in failed AVFs than in preaccess veins. Moreover, there was a positive relationship between the intimal VVD:medial VVD ratio and the intimal thickness:medial thickness ratio (P < .001). In addition, the vascular endothelial cell growth factor A expression was higher in failed AVFs than in preaccess veins.ConclusionsVascularization of the vessel wall was noticeably more developed in the arterialized veins, especially at the NIH regions in failed AVFs.     

Retrospective Comparison of Pulmonary Arteriovenous Malformation Embolization with the Polytetrafluoroethylene-Covered Nitinol Microvascular Plug,AMPLATZER Plug,and Coils in Patients with Hereditary Hemorrhagic Telangiectasia

PurposeTo evaluate effectiveness of the polytetrafluoroethylene-covered nitinol mesh microvascular plug (MVP) and compare it with other devices in pulmonary arteriovenous malformation (PAVM) embolization in patients with hereditary hemorrhagic telangiectasia (HHT).Materials and MethodsTwenty-five patients (average age 35 y; range, 15–56 y) with hereditary hemorrhagic telangiectasia (HHT) and de novo PAVM embolization with at least 1 MVP between November 2015 and May 2017 were retrospectively evaluated. Retrospective data were also obtained from prior embolization procedures in the same patient population with other embolic devices dating back to 2008. Technical success, complications, PAVM persistence rates, and category of persistence were analyzed.ResultsIn 25 patients, 157 PAVMs were treated: 92 with MVP, 35 with AMPLATZER vascular plug (AVP), 6 with AVP plus coils, and 24 with coils. The per-PAVM technical success rates were 100% with MVP; 97%, AVP; 100%, AVP plus coils; and 100%, coils. PAVM persistence rates and median follow-up were as follows: MVP, 2% (1/92) (510 d); AVP, 15% (3/20) (1,447 d); AVP plus coils, 20% (1/5) (1,141 d); coils, 46.7% (7/15) (1,141 d). Persistence owing to recanalization for MVP, AVP, AVP plus coils, and coils was 2%, 15%, 0%, and 33%. No difference was found between persistence rates of MVP vs AVP (P = .098). Embolization with a vascular plug (MVP or AVP) with or without coils had a statistically significant lower persistence rate (5.4%) than embolization with coils alone (46.7%) (P = .022).ConclusionsPAVM embolization with MVP had a high technical success rate and a low persistence rate comparable to AVP and lower than coil embolization alone.     

The Lutonix AV Randomized Trial of Paclitaxel-Coated Balloons in Arteriovenous Fistula Stenosis: 2-Year Results and Subgroup Analysis

PurposeTo present final, 2-year results of a randomized trial comparing paclitaxel-coated vs uncoated balloon angioplasty following vessel preparation with ultra–high-pressure percutaneous transluminal angioplasty (PTA) in hemodialysis arteriovenous fistulae (AVFs).Materials and MethodsTwenty-three sites enrolled 285 subjects with dysfunctional AVFs located in the arm. Before 1:1 randomization, successful vessel preparation was achieved (full waist effacement, < 30% residual stenosis). Follow-up was clinically driven except for a 6-month office visit.ResultsNinety-six of 141 subjects in the drug-coated balloon (DCB) arm and 111 of 144 in the control arm completed the study. Target lesion primary patency (TLPP) rates for the DCB and control groups were 58% ± 4 vs 46% ± 4 (P = .02) at 9 months, 44% ± 5 vs 36% ± 4 (P = .04) at 12 months, 34% ± 5 vs 28% ± 4 (P = .06) at 18 months, and 27% ± 4 vs 24% ± 4 (P = .09) at 24 months, respectively. Mean time to TLPP event for subjects with an event was longer for DCBs (322 vs 207 d; P < .0001). Fewer interventions were needed to maintain target lesion patency in the DCB group at 9 months (P = .02) but not at 12 (P = .08), 18 (P = .13), or 24 months (P = .19). The noninferiority safety target was met at all intervals (P < .01). Mortality did not differ between groups (P = .27). Post hoc analyses showed equivalent DCB effect in all subgroups.ConclusionsTwo-year results demonstrate long-term safety and variable efficacy of DCB angioplasty in AVFs.     

Uterine Artery Embolization following Cesarean Delivery but prior to Hysterectomy in the Management of Patients with Invasive Placenta

PurposeTo evaluate outcomes of patients with placenta accreta spectrum (PAS) disorders who underwent uterine artery embolization (UAE) following cesarean delivery but before hysterectomy.Materials and MethodsA retrospective review of patients with PAS treated with cesarean-hysterectomy (C-hyst) was performed. Patients in the UAE group underwent UAE after cesarean delivery but before hysterectomy; patients in the control group underwent C-hyst alone. Estimated blood loss (EBL), transfusion requirements, length of intensive care unit (ICU) stay, and adverse events were evaluated.ResultsThe study included 31 patients, 7 in the UAE group and 24 in the control group. Median EBL, transfusion requirements, and length of ICU stay in the UAE group compared with control group were 1,500 mL (range, 500–2,000 mL) vs 2,000 mL (range, 1,000–4,500 mL) (P = .04), 150 mL (range, 0–650 mL) vs 550 mL (range, 0–3,125 mL) (P = .10), and 0 d (range, 0–1 d) vs 0.5 d (range, 0–2 d) (P = .07). All patients in the UAE group had placenta increta; patients in the control group had placenta accreta (29%), increta (54%), and percreta (17%) (P = .10). Subgroup analysis of patients with placenta increta demonstrated that the UAE group had a significant decrease in median EBL (P = .004), transfusion requirements (P = .009), and length of ICU stay (P = .04). No adverse events following UAE were noted.ConclusionsUAE following cesarean delivery but before hysterectomy in patients with placenta increta appears to be safe and effective in decreasing EBL, transfusion requirements, and length of ICU stay compared with C-hyst alone.     

A Single-Institutional Comparative Analysis of Advanced Versus Standard Snare Removal of Inferior Vena Cava Filters

PurposeTo investigate differences in procedure time, radiation exposure, and periprocedural complications associated with advanced inferior vena cava (IVC) filter retrieval compared with standard snare retrieval.Materials and MethodsA total of 378 patients underwent standard or advanced IVC filter retrieval over a 5-year period. Technical success, retrieval techniques, fluoroscopy time, radiation dose, and complications were analyzed. All retrieval procedures with techniques other than a “snare-and-sheath” method were categorized as advanced, including failed standard attempts requiring intraprocedural conversion to advanced techniques.ResultsA total of 462 filter retrieval attempts were made in 378 patients (57% female). Success rates for standard and advanced retrieval attempts were 86.8% (317 of 365) and 91.8% (89 of 97), respectively. The rate of periprocedural complications was significantly higher in the advanced retrieval group (P = .006). Complication rates for standard and advanced retrievals were 0.6% (2 of 318; all minor) and 5.2% (5 of 97; 3 minor [3.1%] and 2 major [2.1%]), respectively. The 2 major complications during advanced retrievals included filter fracture and embolization. Average fluoroscopy time for advanced retrievals was significantly higher than for standard retrievals (23.1 min vs 4.3 min; P < .001). Average radiation dose for advanced retrievals was also significantly higher than for standard retrievals (557.2 mGy vs 156.9 mGy; P < .001). Use of general anesthesia was also significantly more common in advanced retrievals compared with standard retrievals (6.2% vs 0.9%; P = .002).ConclusionsAdvanced filter retrieval results in a similarly high rate of technical success compared with standard snare retrieval but is associated with greater fluoroscopy time, anesthesia requirements, and radiation exposure.     

Endovascular Venous Stenosis and Thrombosis Large Animal Model: Angiographic,Histological, and Biomechanical Characterizations

PurposeTo characterize an ovine endovascular radiofrequency (RF) ablation-based venous stenosis and thrombosis model for studying venous biomechanics and response to intervention.Materials and MethodsUnilateral short-segment (n = 2) or long-segment (n = 6) iliac vein stenoses were created in 8 adult sheep using an endovenous RF ablation technique. Angiographic assessment was performed at baseline, immediately after venous stenosis creation, and after 2-week (n = 6) or 3-month (n = 2) survival. Stenosed iliac veins and the contralateral healthy controls were harvested for histological and biomechanical assessment.ResultsAt follow-up, the short-segment RF ablation group showed stable stenosis without occlusion. The long-segment group showed complete venous occlusion/thrombosis with the formation of collateral veins. Stenosed veins showed significant wall thickening (0.28 vs 0.16 mm, P = .0175) and confluent collagen deposition compared with the healthy controls. Subacute nonadherent thrombi were apparent at 2 weeks, which were replaced by fibrous luminal obliteration with channels of recanalization at 3 months. Stenosed veins demonstrated increased longitudinal stiffness (448.5 ± 5.4 vs 314.6 ± 1.5 kPa, P < .0001) and decreased circumferential stiffness (140.8 ± 2.6 vs 246.0 ± 1.6 kPa, P < .0001) compared with the healthy controls.ConclusionEndovenous RF ablation is a reliable technique for creating venous stenosis and thrombosis in a large animal model with histological and biomechanical attributes similar to those seen in humans. This platform can facilitate understanding of venous biomechanics and testing of venous-specific devices and interventions.     

Effectiveness and Safety of Atherectomy versus Plain Balloon Angioplasty for Limb Salvage in Tibioperoneal Arterial Disease

PurposeTo evaluate the effectiveness and safety of atherectomy versus plain balloon angioplasty (POBA) for treatment of critical limb ischemia (CLI) due to tibioperoneal arterial disease (TPAD).Materials and MethodsPatients enrolled in the Vascular Quality Initiative registry who had CLI (Rutherford Class 4–6) and underwent atherectomy versus POBA alone for isolated TPAD were retrospectively identified. Of eligible patients, a cohort of 2,908 patients was propensity matched 1:1 by clinical and angiographic characteristics. The atherectomy group comprised 1,454 patients with 2,183 arteries treated, and the POBA group comprised 1,454 patients with 2,141 arteries treated. The primary study endpoint was major ipsilateral limb amputation. Secondary endpoints were minor ipsilateral amputations, any ipsilateral amputation, primary patency, target vessel reintervention (TVR), and wound healing at 12 months.ResultsThe median follow-up period was 507 days, the mean patient age was 69 years ± 11.7, and the mean occluded length was 6.9 cm ± 6.5. There was a trend toward higher technical success rates with atherectomy than with POBA (92.9% vs 91.0%, respectively; P = .06). The rates of major adverse events during the procedure were not significantly different. The 12-month major amputation rate was similar in the atherectomy and POBA groups (4.5% vs 4.6%, respectively; P = .92; odds ratio, 0.97; 95% CI, 0.68–1.37). There was no difference in 12-month TVR (17.9% vs 17.8%; P = .97) or primary patency (56.4% vs 54.5%; P = .64) between the atherectomy and POBA groups.ConclusionsIn a large national registry, treatment of CLI from TPAD using atherectomy versus POBA showed no significant differences in procedural adverse events, major amputations, TVR, or vessel patency at 12 months.     

4D Flow MR Imaging to Improve Microwave Ablation Prediction Models: A Feasibility Study in an In Vivo Porcine Liver

PurposeTo characterize the effect of hepatic vessel flow using 4-dimensional (4D) flow magnetic resonance (MR) imaging and correlate their effect on microwave ablation volumes in an in vivo non-cirrhotic porcine liver model.Materials and MethodsMicrowave ablation antennas were placed under ultrasound guidance in each liver lobe of swine (n = 3 in each animal) for a total of 9 ablations. Pre- and post-ablation 4D flow MR imaging was acquired to quantify flow changes in the hepatic vasculature. Flow measurements, along with encompassed vessel size and vessel-antenna spacing, were then correlated with final ablation volume from segmented MR images.ResultsThe linear regression model demonstrated that the preablation measurement of encompassed hepatic vein size (β = –0.80 ± 0.25, 95% confidence interval [CI] –1.15 to –0.22; P = .02) was significantly correlated to final ablation zone volume. The addition of hepatic vein flow rate found via 4D flow MRI (β = –0.83 ± 0.65, 95% CI –2.50 to 0.84; P = .26), and distance from antenna to hepatic vein (β = 0.26 ± 0.26, 95% CI –0.40 to 0.92; P = .36) improved the model accuracy but not significantly so (multivariate adjusted R² = 0.70 vs univariate (vessel size) adjusted R² = 0.63, P = .24).ConclusionsHepatic vein size in an encompassed ablation zone was found to be significantly correlated with final ablation zone volume. Although the univariate 4D flow MR imaging-acquired measurements alone were not found to be statistically significant, its addition to hepatic vein size improved the accuracy of the ablation volume regression model. Pre-ablation 4D flow MR imaging of the liver may assist in prospectively optimizing thermal ablation treatment.     

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.     

Transarterial Radioembolization versus Transarterial Chemoembolization Plus Percutaneous Ablation for Unresectable,Solitary Hepatocellular Carcinoma of ≥3 cm: A Propensity Score–Matched Study

PurposeTo compare the safety and effectiveness of transarterial radioembolization (TARE) and transarterial chemoembolization with drug-eluting embolic agents combined with percutaneous ablation (transarterial chemoembolization [TACE] + ablation) in the treatment of treatment-naïve, unresectable, solitary hepatocellular carcinoma (HCC) of ≥3 cm.Materials and MethodsTwenty-nine patients with treatment-naïve, unresectable, solitary HCC of ≥3 cm received combined TACE + ablation, and 40 patients received TARE at a single institution. Local tumor response, tumor progression-free survival (PFS), overall survival, need for reintervention, bridge to transplant, and major complications were compared. Clinical variables and outcomes were compared before and after propensity score matching (PSM).ResultsBefore PSM, patients who underwent TARE had a larger tumor size (3.7 vs 5.5 cm; P = .0005) and were older (61.5 vs 69.3 years; P = .0014). After PSM, there was no difference in baseline characteristics between the 2 groups, with the mean tumor sizes measuring 3.9 and 4.1 cm in the TACE + ablation and TARE cohorts, respectively. After PSM (n = 19 in each group), no statistically significant difference was observed in local radiological response (disease control rates, 100% vs 94.7%; P = .31), survival (subdistribution hazard ratio [SHR], 0.71; 95% confidence interval [CI], 0.28–1.80; P = .469), PFS (SHR, 0.61; 95% CI, 0.21–1.71; P = .342), bridge to transplant (21.1% vs 31.6%, P = .46), and major adverse event rates (15.8% vs 10.5%, P = .63) between the 2 groups. The mean total number of locoregional interventions was higher in the TACE + ablation cohort (1.9 vs 1.3 sessions, P = .02), with an earlier median reintervention trend (SHR, 0.61; 95% CI, 0.20–1.32; P = .167).ConclusionsThe present study showed that TARE and the combination of TACE and ablation are comparable in safety and effectiveness for treating treatment-naïve, unresectable, solitary HCC of ≥3 cm.     

Endovascular Revascularization as Primary Treatment for Acute Embolic Mesenteric Ischemia: Stent Thrombectomy plus Aspiration versus Aspiration Alone

PurposeTo investigate the outcomes of stent thrombectomy combined with aspiration versus aspiration alone in acute mesenteric ischemia (AMI).Materials and MethodsThis was a single-center, retrospective cohort study. Between May 1, 2012, and January 1, 2021, 41 patients (mean age, 73.8 years ± 7.9) with AMI who underwent stent thrombectomy plus aspiration (Group 1, n = 14) or aspiration alone (Group 2, n = 27) were included. The treatment regimens and clinical and follow-up outcomes of the patients were reviewed and analyzed. Group differences were compared using a χ² test, Fisher exact test, independent t test, or Mann-Whitney U test. The cumulative survival rate was calculated using a Kaplan-Meier curve.ResultsThe overall clinical success rate was 78.0% (32/41), and no significant differences were found between Group 1 and Group 2 (78.6% vs 77.8%, P = 1.00). Compared with Group 2, Group 1 was associated with a higher complete clearance rate (44.4% vs 78.6%, P = .04), less adjunctive local thrombolysis (48.1% vs 14.3%, P = .03), and a shorter length of hospital stay (10.7 days ± 9.0 vs 5.7 days ± 4.7, P = .03). The estimated survival rates at 1 month, 3 months, 6 months, 1 year, and 2 years were 73.2%, 72.5%, 71.4%, 65.3%, and 59.8%, respectively. No significant difference was found in the survival rate between the groups (log-rank test, P = .96). The recurrence rates for Group 1 and Group 2 were 8.3% (1/12) and 4.0% (1/25), respectively.ConclusionsCompared with aspiration alone, aspiration combined with stent thrombectomy showed a higher complete clearance rate, reduced adjunctive thrombolysis, and a shorter length of hospital stay.     

Association between Radiation Exposure and Endothelium-Dependent Vasodilation: Results from Clinical and Experimental Studies

PurposeThe association between occupational radiation exposure and endothelium-dependent vasodilation (EDV) remains unclear. This study evaluated the association between radiation exposure and EDV among fluoroscopy-guided interventional procedure specialists and explored the possible mechanisms.Materials and MethodsBrachial flow-mediated dilation was compared in 21 interventional cardiologists (the radiation group) and 15 noninterventional cardiologists (the nonradiation group). Animal radiation experiments were also performed to observe the impact of radiation on EDV.ResultsFlow-mediated dilation in both the left (radiation group, 3.63% vs. nonradiation group, 6.77%; P < .001) and right brachial arteries (5.36% vs. 7.33%, respectively; P = .04) and serum nitric oxide (NO) level (343.69 vs. 427.09 μmol/L, respectively; P = .02) were significantly reduced in the radiation group compared to those in the nonradiation group. EDV was significantly impaired in acetylcholine concentrations of 3 × 10⁻⁶ mol/L and 10⁻⁵ mol/L (60.09% vs.74.79%, respectively; P = .03; and 62.73% vs. 80.56%, respectively; P = .002), and reactive oxygen species levels in the aorta intima and media layers were significantly increased in mice after a single x-ray exposure, which could be partly rescued by pretreatment with folic acid (P < .05).ConclusionsRadiation exposure can lead to impairment of flow-mediated vasodilation in human or EDV in mice. In mice acutely exposed to radiation, folic acid alleviated radiation-induced EDV impairment by possible reduction of reactive oxidative species.     

Stereotactic Body Radiotherapy for Stage I Renal Cell Carcinoma: National Treatment Trends and Outcomes Compared to Partial Nephrectomy and Thermal Ablation

PurposeTo assess use of stereotactic body radiotherapy (SBRT) for stage I renal cell carcinoma (RCC) and compare outcomes with thermal ablation and partial nephrectomy (PN).Materials and MethodsThe 2004–2015 National Cancer Database was investigated for histopathologically proven stage I RCC treated with PN, cryoablation, radiofrequency (RF) or microwave (MW) ablation, or SBRT. Patients were propensity score–matched to account for potential confounders, including patient age, sex, race, comorbidities, tumor size, histology, grade, tumor sequence, administration of systemic therapy, treatment in academic vs nonacademic centers, treatment location, and year of diagnosis. Overall survival (OS) was evaluated with Kaplan-Meier plots, log-rank tests, and Cox proportional hazards models.ResultsA total of 91,965 patients were identified (SBRT, n = 174; PN, n = 82,913; cryoablation, n = 5,446; RF/MW ablation, n = 3,432). Stage I patients who received SBRT tended to be older women with few comorbidities treated at nonacademic centers in New England states. After propensity score matching, a cohort of 636 patients was obtained with well-balanced confounders between treatment groups. In the matched cohort, OS after SBRT was inferior to OS after PN and thermal ablation (PN vs SBRT, hazard ratio [HR] = 0.29, 95% confidence interval [CI] 0.19–0.46, P < .001; cryoablation vs SBRT, HR = 0.40, 95% CI 0.26–0.60, P < .001; RF/MW ablation vs SBRT, HR = 0.46, 95% CI 0.31–0.67, P < .001). Compared with PN, neither cryoablation nor RF/MW ablation showed significant difference in OS (cryoablation vs PN, HR = 1.35, 95% CI 0.80–2.28, P = .258; RF/MW ablation vs PN, HR = 0.64, 95% CI 0.95–2.55, P = .079).ConclusionsCurrent SBRT protocols show lower OS compared with thermal ablation and PN, whereas thermal ablation and PN demonstrate comparable outcomes.     

Single-Center Retrospective Comparative Analysis of Transradial,Transbrachial, and Transfemoral Approach for Mesenteric Arterial Procedures

PurposeTo assess feasibility and safety of transradial access (TRA) compared with transfemoral access (TFA) and transbrachial access (TBA) for mesenteric arterial endovascular procedures.Materials and MethodsA retrospective cohort analysis was performed including all consecutive patients who underwent a mesenteric arterial procedure in a tertiary referral center between May 2012 and February 2018. Exclusion criteria were absence of data and lost to follow-up within 24 hours after the procedure. During the study period, 103 patients underwent 148 mesenteric arterial procedures (TBA, n = 52; TFA, n = 39; TRA, n = 57). Mean patient age was 64.3 years ± 13.3, and 91 patients (62%) were women. Primary outcomes were vascular access specified technical success rate and access site complication rate, as reported in hospital records.ResultsTechnical success rate specified for the vascular access technique did not differ between the 3 approaches (TBA 96%, TFA 87%, TRA 91%; TRA vs TBA, P = .295; TBA vs TFA, P = .112; TRA vs TFA, P = .524), and overall access site complication rate was not different between the 3 approaches (TBA 42%, TFA 23%, TRA 35%; TRA vs TBA, P = .439; TBA vs TFA, P = .055; TRA vs TFA, P = .208). However, more major access site complications were reported for TBA than for TRA or TFA (TBA 17%, TFA 3%, TRA 2%; TRA vs TBA, P = .005; TBA vs TFA, P = .026; TRA vs TFA, P = .785).ConclusionsTRA is a safe and feasible approach for mesenteric arterial procedures comparable to TFA, but with a significantly lower major access site complication rate than TBA.     

Evaluation of the Benefit of Extended Catheter-Directed Thrombolysis with Serial Angiography for Acute Pulmonary Embolism

PurposeTo evaluate whether extended catheter-directed thrombolysis (CDT) with repeat visits to the angiography suite provide added benefit in treatment of acute pulmonary embolism (PE).Materials and MethodsThis was a retrospective review of CDT procedures performed for acute PE in 156 patients (age 56.1 y ± 15.3, 46.2% women) between 2009 and 2019. All patients underwent at least 1 follow-up visit to the angiography suite for evaluation of pulmonary artery pressure (PAP) and thrombus burden (Miller score) before termination (111/156, 71.2%) or continuation of CDT (45/156, 28.8%).ResultsPatients who had CDT extended beyond the first follow-up visit required a higher total dose of tissue plasminogen activator (40.7 mg ± 14.3 vs 22.6 mg ± 9.9, P < .001) to achieve a similar final Miller score (6.4 ± 3.8 vs 7.6 ± 3.9, P = .1) and a similar reduction in systolic PAP (?14.4 mm Hg ± 10.2 vs ?12.6 mm Hg ± 11.9, P = .6). The initial Miller scores were similar in both groups (19.7 ± 5.8 vs 19 ± 4, P = .4) but were significantly higher during the first follow-up visit (after 18 hours ± 5.5 vs 20 hours ± 4.8, P = .06) in patients requiring multiple follow-up visits (12.2 ± 5 vs 7.6 ± 3.9, P < .001). Multiple regression analyses identified heart rate > 100 beats/min and systolic PAP > 55 mm Hg as associated with the need for extended CDT. Extended CDT did not result in a higher hemorrhagic complication rate (1/45 vs 6/111, P = .7).ConclusionsPatients presenting with higher heart rates and systolic PAP may benefit from extended CDT to achieve similar reductions in PAP and thrombus burden, without clear added risk of hemorrhage.     

Percutaneous Gastrostomy Compared with Esophageal Stent Placement for the Treatment of Esophageal Cancer with Dysphagia

PurposeTo compare the outcomes of self-expandable metal stent placement and percutaneous gastrostomy (PG) for the treatment of patients with esophageal cancer (EC) and dysphagia.Materials and MethodsThis retrospective observational study consisted of 113 patients with EC and dysphagia who underwent either stent placement (n = 47) or PG (n = 66) at a single center between June 2014 and June 2018.ResultsThere were 63 men and 50 women, with a mean age of 76.5 years (standard deviation 4.9 years). The 2 groups had similar baseline characteristics, except that the PG group had a higher percentage of patients with cervical EC (22.7% vs 2.1%, P < .001). The PG group had better maintenance of nutritional status in terms of reduction in serum albumin level (P = .039) and weight loss (P = .041). Compared with the stent group, the PG group demonstrated a lower incidence of local severe pain (0% vs 21.3%, P < .001) and lower incidence of dislodgment of device (1.5% vs 19.1%, P = .002). The PG group demonstrated longer overall survival compared with the stent group for Stages II and III (201 vs 185 days, P = .034) and Stage IV (122 vs 86 days, P = .001).ConclusionsCompared with stent insertion, PG is associated with better maintenance of nutritional status, fewer complications, and better survival. Thus, PG may be the preferred choice for treating malnutrition in patients with EC and dysphagia.