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.     

Large-Bore Aspiration Thrombectomy versus Catheter-Directed Thrombolysis for Acute Pulmonary Embolism: A Propensity Score–Matched Comparison

PurposeTo compare effectiveness and safety of large-bore aspiration thrombectomy (LBAT) with catheter-directed thrombolysis (CDT) for treatment of acute massive and submassive pulmonary embolism (PE).Materials and MethodsThis retrospective review included patients with acute PE treated with LBAT or CDT using tissue plasminogen activator (tPA) between December 2009 and May 2020. A propensity score based on Pulmonary Embolism Severity Index class and PE severity (massive vs submassive) was calculated, and 26 LBAT cases (age 60.2 y ± 17.1, 14/26 women) were matched with 26 CDT cases (age 59.7 y ± 14.2, 14/26 women).ResultsThe CDT group had 22.1 mg ± 8.1 tPA infused over 21.2 h ± 6.6. Both groups demonstrated similar initial and final systolic pulmonary artery pressure (PAP) (LBAT: 54.5 mm Hg ± 12.9 vs CDT: 54.5 mm Hg ± 16.3, P = .8, and LBAT: 42.5 mm Hg ± 14.1 vs CDT: 42.6 mm Hg ± 12.1, P = .8, respectively) and similar reductions in heart rate (LBAT: −5.4 beats/min ± 19.2 vs CDT: −9.6 beats/min ± 15.8, P = .4). CDT demonstrated a higher reduction in Miller score (−10.1 ± 3.9 vs −7.5 ± 3.8, P = .02). LBAT resulted in 1 minor hemorrhagic complication and 2 procedure-related mortalities, and CDT resulted in 1 minor and 1 major hemorrhagic complication.ConclusionsLBAT and CDT resulted in similar reductions of PAP and heart rate when used to treat acute PE. CDT reduced thrombus burden to a greater degree. Although hemorrhagic complications rates were not significantly different, the LBAT group demonstrated a higher rate of procedure-related mortality. Larger studies are needed to compare the safety of these techniques.     

The Effect of Endovascular Treatment of Renal Artery Stenoses on Coexistent Aneurysms Associated with Fibromuscular Dysplasia

PurposeEndovascular data on patients with coexistent renal artery stenosis (RAS) and renal artery aneurysm (RAA) caused by fibromuscular dysplasia (FMD) are scarce, and the outcomes from RAS-specific treatment on RAA remain unclear. This study aimed to evaluate the safety and effectiveness of RAS-specific endovascular management in patients with coexisting RAA caused by FMD.Materials and MethodsClinical and endovascular data on 19 patients with coexistent RAS and RAA caused by FMD who underwent RAS-specific endovascular therapy were analyzed prospectively. An RAA located within 10 mm of the RAS was defined as a stenosis-related RAA (SRAA), and long-term outcomes were evaluated.ResultsNineteen patients (24 RASs and 30 RAAs) underwent endovascular therapy. Twenty-one RASs were treated with balloon angioplasty alone, whereas 3 RASs were treated with stent implantation. None of the RAAs were treated directly. During an average of 4.2 years ± 3.2 of follow-up, systolic and diastolic blood pressures decreased from 183.0 mm Hg ± 19.5 and 120.2 mm Hg ± 19.0 to 127.9 mm Hg ± 10.3 and 80.9 mm Hg ± 6.9, respectively; the number of antihypertensive medications reduced from 1.7 ± 1.0 to 0.8 ± 0.3 (for all, P < .001). The serum creatinine level remained stable. The maximum diameter of all RAAs decreased from 14.6 mm ± 9.7 to 11.3 mm ± 8.4 (P < .001). There was a significant difference in the improvement rate of the maximum diameter between SRAAs (65.0%, 13 of 20) and non-SRAAs (20.0%, 2 of 10) (P = .019).ConclusionsRAS-specific endovascular therapy is safe and effective and possibly aids in preventing RAA progression in patients with FMD with coexistent RAS and RAA.     

Transjugular Intrahepatic Portosystemic Shunt and Thrombectomy (TIPS-Thrombectomy) for Symptomatic Acute Noncirrhotic Portal Vein Thrombosis

PurposeTo report the safety and effectiveness of transjugular intrahepatic portosystemic shunt and mechanical thrombectomy (TIPS-thrombectomy) for symptomatic acute noncirrhotic portal vein thrombosis (NC-PVT).Materials and MethodsPatients with acute NC-PVT who underwent TIPS-thrombectomy between 2014 and 2021 at a single academic medical center were retrospectively reviewed. Thirty-two patients were included (men, 56%; median age, 51 years [range, 39–62 years]). The causes for PVT included idiopathic (n = 12), prothrombotic disorders (n = 11), postsurgical sequelae (n = 6), pancreatitis (n = 2), and Budd-Chiari syndrome (n = 1). The indications for TIPS-thrombectomy included refractory abdominal pain (n = 14), intestinal venous ischemia (n = 9), ascites (n = 4), high-risk varices (n = 3), and variceal bleeding (n = 2). Variables studied included patient, disease, and procedure characteristics. Patients were monitored over the course of 1-year follow-up.ResultsSuccessful recanalization of occluded portal venous vessels occurred in all 32 patients (100%). Compared with pretreatment patency, recanalization with TIPS-thrombectomy resulted in an increase in patent veins (main portal vein [28% vs 97%, P < .001], superior mesenteric vein [13% vs 94%, P < .001], and splenic vein [66% vs 91%, P < .001]). Three procedure-related adverse events occurred (Society of Interventional Radiology grade 2 moderate). Hepatic encephalopathy developed in 1 (3%) of 32 patients after TIPS placement. At 1-year follow-up, return of symptoms occurred in 3 (9%) of 32 patients: (a) ascites (n = 1), (b) variceal bleeding (n = 1), and (c) intestinal venous ischemia (n = 1). The intention-to-treat 1-year portal vein and TIPS primary and secondary patency rates were 78% (25/32) and 100% (32/32), respectively. Seven patients required additional procedures, and the 1-year mortality rate was 3% (1/32).ConclusionsTIPS-thrombectomy is a safe and effective method for treating patients with symptomatic acute NC-PVT.     

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.     

Ultrasound-Accelerated,Catheter-Directed Thrombolysis for Submassive Pulmonary Embolism: Single-Center Retrospective Review with Intermediate-Term Outcomes

PurposeTo evaluate ultrasound-accelerated, catheter-directed thrombolysis (CDT) for treatment of acute submassive pulmonary embolism (PE).Materials and MethodsThis single-center, retrospective study included patients who underwent CDT for acute submassive PE (N = 113, 52% men/48% women) from 2013 to 2017. Baseline characteristics included history of deep venous thrombosis (12%), history of PE (6%), and history of cancer (18%). Of cohort patients, 88% (n=99) had a simplified PE severity index score of ≥ 1 indicating a high risk of mortality.ResultsA technical success rate of 100% was achieved with 84% of patients having bilateral catheter placements. Average tissue plasminogen activator (tPA) therapy duration was 20.7 hours ± 1.5, and median tPA dose was 21.5 mg. Three patients (2.6%) experienced minor hemorrhagic complications. Mean hospital length of stay was 6 days. Mean pulmonary arterial pressure decreased from 55 mm Hg on presentation to 37 mm Hg (P < .01) 1 day following initiation of thrombolytic therapy. All-cause mortality rate of 4% (n = 4) was noted on discharge, which increased to 6% (n = 7) at 6 months. At 6-month follow-up compared with initial presentation, symptom improvements (93%), physiologic improvements (heart rate 72 beats/min vs 106 beats/min, P < .01), oxygen requirement improvements (fraction of inspired oxygen 20% vs 28%, P < .01), and right ventricular systolic pressure improvements by echocardiography (30 mm Hg vs 47 mm Hg, P < .01) were observed.ConclusionsCDT for acute submassive PE was associated with low complications and mortality, decreased right ventricular systolic pressure, high rates of clinical improvement, and improved intermediate-term clinical outcomes.     

Portal Vein Recanalization for Noncirrhotic Portal Vein Cavernous Transformation: Transjugular Intrahepatic Portosystemic Shunt Creation versus Portal Vein Stent Placement

PurposeTo compare the clinical outcomes of transjugular intrahepatic portosystemic shunt (TIPS) creation versus portal vein stent placement (PVS) in patients with noncirrhotic cavernous transformation of the portal vein (CTPV).Materials and MethodsIn this retrospective study, clinical data from patients with noncirrhotic CTPV who underwent TIPS creation or PVS were compared. A total of 54 patients (mean age, 43.8 years ± 15.8; 31 men and 23 women) were included from January 2013 to January 2021; 29 patients underwent TIPS creation, and 25 patients underwent PVS. Stent occlusion, variceal rebleeding, survival, and postprocedural complications were compared between the 2 groups.ResultsThe mean follow-up time was 40.2 months ± 26.2 in the TIPS group and 35.3 months ± 21.1 in the PVS group. The stent occlusion rate in the PVS group (16%, 4 of 25) was significantly lower than that in the TIPS group (41.4%, 12 of 29) during the follow-up (P = .042). The cumulative variceal rebleeding rates in the TIPS group were significantly higher than those in the PVS group (28% vs 4%; P = .027). The procedural success rate was 69% in the TIPS group and 86% in the PVS group (P = .156). There was a higher number of severe adverse events after TIPS than after PVS (0% vs 24%; P = .012).ConclusionsPortal vein recanalization with PVS may be a preferable alternative to TIPS creation in the treatment of noncirrhotic CTPV because of higher stent patency rates, lower risk of variceal rebleeding, and fewer adverse events.     

Combination of Microwave Ablation and Percutaneous Osteoplasty for Treatment of Painful Extraspinal Bone Metastasis

PurposeTo evaluate the efficacy and safety of microwave (MW) ablation combined with percutaneous osteoplasty (POP) on painful extraspinal bone metastases.Materials and MethodsIn this retrospective study, 50 adult patients with 56 extraspinal bone metastasis lesions, who suffered from refractory moderate to severe pain, were treated with MW ablation and POP. Changes in quality of life were evaluated based on the Visual Analog Scale (VAS), daily morphine consumption, and the Oswestry Disability Index (ODI) before and immediately after the procedure and during follow-up times.ResultsTechnical success was achieved in all patients. Mean preoperative VAS score and morphine dose were 7.0 ± 2.6 (range, 3–10) and 66.7 ± 33.2 mg (range, 10–120 mg), respectively. Mean postoperative VAS scores and daily morphine doses were as follows: 1 day, 3.5 ± 2.1 and 36.1 ± 25.8 mg (P < .05); 1 week, 1.5 ± 1.7 and 12.2 ± 14.8 mg (P < .001); 1 month, 0.9 ± 1.4 and 5.7 ± 10.0 mg (P < .001); and 3 months, 0.6 ± 1.2 and 4.7 ± 8.4 mg (P < .001). A significant decrease in the ODI score was also observed (P < .05). Periprocedural death was not observed. A pathologic fracture occurred in 1 (2%) patient with femoral metastasis, and local infection was observed in 2 (4%) patients. Minor cement leakage occurred in 4 (8%) patients with no symptomatic or intra-articular extravasation. No local tumor progression occurred in patients with imaging follow-up.ConclusionsMW ablation combined with POP is an effective and safe treatment for painful extraspinal bone metastases, which can significantly relieve pain and improve quality of life.     

Short-Term Results of Plug-Assisted Retrograde Transvenous Obliteration for Portal Steal from Complicated Portosystemic Shunts in Living-Donor Liver Transplantation

PurposeTo investigate the effectiveness of plug-assisted retrograde transvenous obliteration (PARTO) for portal steal from complicated portosystemic shunts (PSSs) in living-donor liver transplantation (LDLT).Materials and MethodsThis retrospective study included consecutive patients who underwent LDLT and intraoperative or postoperative PARTO for complicated PSS between January 2020 and December 2021. PARTO was performed when hepatofugal portal flow steal was identified during intraoperative cineportography, and afferent vein embolization was difficult because of multiple afferent veins or incomplete afferent vein embolization. Liver volume, complete obliteration of PSS, technical success, adverse events, and follow-up clinical and laboratory data were evaluated.ResultsThirty-seven patients were included, and the technical success rate was 100% with no major adverse events. During the median follow-up of 20.0 months, all patients recovered well with suitable regeneration of the liver without graft dysfunction related to a portal steal. The liver volume significantly increased within 1 month (median, 956 vs 1,198 mL; P < .001). Complete obliteration of a PSS occurred in 36 of 37 (97.3%) patients, and there was no recurrence during follow-up. The Child-Pugh score, serum albumin and total bilirubin levels, and prothrombin time showed significant improvement over serial follow-up. Compared with preprocedural values (14.9 cm/s), follow-up portal flow (median) peaked on the first day (71.2 cm/s, P < .001) and then remained significantly high at 1 week (60.3 cm/s, P < .001) and 1 month (53.1 cm/s, P < .001), in accordance with the graft regeneration.ConclusionsPARTO is an effective procedure for the treatment of complicated PSS in LDLT.     

Dynamic Contrast-Enhanced MR Imaging Evaluation of Perfusional Changes and Ablation Zone Size after Combination Embolization and Ablation Therapy

PurposeThe objectives of this study were to assess the utility of dynamic contrast-enhanced magnetic resonance (MR) imaging in quantifying parenchymal perfusional changes after embolization and to characterize the association between pharmacokinetic (PK) parameters and final microwave ablation volume.Materials and MethodsPK parameters from dynamic contrast-enhanced MR imaging were used to quantify perfusional changes in the liver after transarterial embolization of the right or left lobe in a swine liver model (n = 5). Each animal subject subsequently underwent microwave ablation (60 W for 5 minutes) of the embolized and nonembolized liver lobes. Changes in PK parameters from dynamic contrast-enhanced MR imaging were correlated with their respective final microwave ablation volumes in each liver lobe.ResultsMicrowave ablation volumes of embolized liver lobes were significantly larger than those of nonembolized liver lobes (28.0 mL ± 6.2 vs 15.1 mL ± 5.2, P < .001). PK perfusion parameters were significantly lower in embolized liver lobes than in nonembolized liver lobes (K^trans = 0.69 min^?1 ± 0.15 vs 1.52 min^?1 ± 0.37, P < .001; k_ep = 0.69 min^?1 ± 0.19 vs 1.54 min^?1 ± 0.42, P < .001). There was a moderate but significant correlation between normalized k_ep and ablation volume, with each unit increase in normalized k_ep corresponding to a 9.8-mL decrease in ablation volume (P = .035).ConclusionsPK-derived parameters from dynamic contrast-enhanced MR imaging can be used to quantify perfusional changes after transarterial embolization and are directly inversely correlated with final ablation volume.     

Quantitative Automated Segmentation of Lipiodol Deposits on Cone-Beam CT Imaging Acquired during Transarterial Chemoembolization for Liver Tumors: A Deep Learning Approach

PurposeTo show that a deep learning (DL)–based, automated model for Lipiodol (Guerbet Pharmaceuticals, Paris, France) segmentation on cone-beam computed tomography (CT) after conventional transarterial chemoembolization performs closer to the “ground truth segmentation” than a conventional thresholding-based model.Materials and MethodsThis post hoc analysis included 36 patients with a diagnosis of hepatocellular carcinoma or other solid liver tumors who underwent conventional transarterial chemoembolization with an intraprocedural cone-beam CT. Semiautomatic segmentation of Lipiodol was obtained. Subsequently, a convolutional U-net model was used to output a binary mask that predicted Lipiodol deposition. A threshold value of signal intensity on cone-beam CT was used to obtain a Lipiodol mask for comparison. The dice similarity coefficient (DSC), mean squared error (MSE), center of mass (CM), and fractional volume ratios for both masks were obtained by comparing them to the ground truth (radiologist-segmented Lipiodol deposits) to obtain accuracy metrics for the 2 masks. These results were used to compare the model versus the threshold technique.ResultsFor all metrics, the U-net outperformed the threshold technique: DSC (0.65 ± 0.17 vs 0.45 ± 0.22, P < .001) and MSE (125.53 ± 107.36 vs 185.98 ± 93.82, P = .005). The difference between the CM predicted and the actual CM was 15.31 mm ± 14.63 versus 31.34 mm ± 30.24 (P < .001), with lesser distance indicating higher accuracy. The fraction of volume present ([predicted Lipiodol volume]/[ground truth Lipiodol volume]) was 1.22 ± 0.84 versus 2.58 ± 3.52 (P = .048) for the current model’s prediction and threshold technique, respectively.ConclusionsThis study showed that a DL framework could detect Lipiodol in cone-beam CT imaging and was capable of outperforming the conventionally used thresholding technique over several metrics. Further optimization will allow for more accurate, quantitative predictions of Lipiodol depositions intraprocedurally.     

Safety and Effectiveness of Expandable Intravertebral Implant Use for Thoracolumbar Burst Fractures

PurposeTo determine the safety and effectiveness of an expandable intravertebral implant (Spinejack; Stryker, Kalamazoo, Michigan) as a treatment option for patients with thoracolumbar spine burst fractures without fracture-related neurologic deficit.Materials and MethodsImaging studies before and after expandable intravertebral implantation and medical records of 33 patients, 11 (33.3%) men and 22 (66.6%) women with an overall mean age of 71.7 years ± 8.3, were reviewed for 60 thoracolumbar Magerl Type A3 injuries secondary to osteoporosis, trauma, or malignancy. The mean follow-up time was 299 days.ResultsImplantation of an expandable intravertebral device resulted in a statistically significant reduction in bone fragment retropulsion (mean ± SD, 0.64 mm ± 16.4; P < .001), reduction in the extent of canal compromise (mean, 5.5%; P < .001), increased central canal diameter (mean ± SD, 0.71 mm ± 1.3; P < .001), and restoration of vertebral body height, with a mean increase of 5.0 mm (P < .001). However, the implantation did not result in a statistically significant kyphosis reduction (mean, 1.38°; P = .10). All patients except for 1 reported improvement in pain after surgery, with a mean improvement of 1.54 on a 4-point pain scale (P < .001). No clinically significant adverse events were reported.ConclusionsThis study suggests that expandable intravertebral device implantation is a safe and effective treatment for thoracolumbar vertebral burst fractures in patients without fracture-related neurologic deficit. Although implantation did not result in a statistically significant reduction in kyphotic angle, it offered significant improvement in pain, vertebral body height, fracture fragment retropulsion, and central canal diameter compromise.     

A Motion Artifact Correction Algorithm for Cone-Beam CT in Patients with Hepatic Malignancies Treated with Transarterial Chemoembolization

PurposeTo evaluate the effect of a motion artifact correction algorithm (MACA) on cone-beam computed tomography (CT) during transarterial chemoembolization for hepatic malignancies.Materials and MethodsFrom June 2020 to March 2021, 42 patients with mild-to-severe motion artifacts detected using single cone-beam CT scans were evaluated retrospectively. The image quality of native and motion-corrected data was compared. The maximum intensity, sharpness, and full width at half maximum (FWHM) of 5 segmental hepatic arteries were quantitatively measured. The overall quality of maximum intensity projection (MIP) images, conspicuity of tumor-supplying arteries, and need for selective angiography to ascertain the vascular anatomy were qualitatively evaluated by multiple readers. Paired t and Wilcoxon signed rank tests were used to compare the parameters.ResultsThe mean maximum intensity and sharpness increased from 2,792.01 HU ± 451.36 to 3,148.40 HU ± 594.46 and from 0.31 ± 0.02/mm to 0.34 ± 0.02/mm, respectively, using the MACA (both P < .001). The MACA decreased the mean FWHM from 2.02 mm ± 0.27 to 1.78 mm ± 0.26 (P < .001). The overall quality of the MIP images and the conspicuity of the tumor-supplying artery were enhanced from 2.5 to 3.0 points and from 3.0 to 4.0 points, respectively (both P < .001). Selective angiography was expected to be omitted in 7 cases (16.7%, 7/42) after using the MACA.ConclusionsThe MACA significantly improved both quantitative and qualitative image quality of cone-beam CT in selected patients with motion artifacts during transarterial chemoembolization for hepatic malignancies.     

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.     

Endovascular Pressure Measurements to Assess the Functional Severity of Mesenteric Arterial Stenoses

PurposeTo assess the ability of pressure measurements to discriminate clinically significant celiac artery (CA) or superior mesenteric artery (SMA) stenosis in patients with suspected chronic mesenteric ischemia (CMI).Materials and MethodsSingle-center, retrospective cohort study of 41 intra-arterial pressure measurements during mesenteric angiography with intended revascularization, performed in 37 patients (mean age 67.7 ± 10.8 years, 62% female) between April 2015 and May 2017. Simultaneous prestenotic and poststenotic pressure measurements had been obtained before and after intra-arterial administration of nitroglycerin. Revascularization was performed in 38 of 41 procedures. Definitive diagnosis of CMI was defined as patient-reported symptom relief or improvement after successful revascularization.ResultsPressure gradients obtained after vasodilator administration were significantly higher in CAs and SMAs with ≥50% stenosis. Pressure ratios (pressure distal [Pd]/pressure aorta [Pa]) obtained after vasodilator administration were significantly higher in CAs with ≥50% stenosis. Subgroup analysis of 22 patients with a ≥50% stenosis of either CA or SMA showed significantly higher pressure gradients and Pd/Pa ratios after vasodilator administration in CMI patients (median pressure gradient: CMI [interquartile ratio] 36 [21-40] mm Hg versus no-CMI 20 [9-21] mm Hg, P = 0.041; Pd/Pa: CMI 0.703 [0.598-0.769] versus no-CMI 0.827 [0.818-0.906], P = .009). A ≤0.8 Pd/Pa cutoff value after administration of a vasodilator best identified a clinically relevant stenosis, with 86% sensitivity and 83% specificity. Complications related to the pressure measurements were not observed.ConclusionsIntra-arterial pressure measurements are feasible and safe. Low Pd/Pa ratios were associated with clinically relevant CA or SMA stenosis.     

Percutaneous CT-Guided Abdominal and Pelvic Biopsies: Comparison of an Electromagnetic Navigation System and CT Fluoroscopy

PurposeTo compare electromagnetic navigation (EMN) with computed tomography (CT) fluoroscopy for guiding percutaneous biopsies in the abdomen and pelvis.Materials and MethodsA retrospective matched-cohort design was used to compare biopsies in the abdomen and pelvis performed with EMN (consecutive cases, n = 50; CT-Navigation; Imactis, Saint-Martin-d’Hères, France) with those performed with CT fluoroscopy (n = 100). Cases were matched 1:2 (EMN:CT fluoroscopy) for target organ and lesion size (±10 mm).ResultsThe population was well-matched (age, 65 vs 65 years; target size, 2.0 vs 2.1 cm; skin-to-target distance, 11.4 vs 10.7 cm; P > .05, EMN vs CT fluoroscopy, respectively). Technical success (98% vs 100%), diagnostic yield (98% vs 95%), adverse events (2% vs 5%), and procedure time (33 minutes vs 31 minutes) were not statistically different (P > .05). Operator radiation dose was less with EMN than with CT fluoroscopy (0.04 vs 1.2 μGy; P < .001), but patient dose was greater (30.1 vs 9.6 mSv; P < .001) owing to more helical scans during EMN guidance (3.9 vs 2.1; P < .001). CT fluoroscopy was performed with a mean of 29.7 tap scans per case. In 3 (3%) cases, CT fluoroscopy was performed with gantry tilt, and the mean angle out of plane for EMN cases was 13.4°.ConclusionsPercutaneous biopsies guided by EMN and CT fluoroscopy were closely matched for technical success, diagnostic yield, procedure time, and adverse events in a matched cohort of patients. EMN cases were more likely to be performed outside of the gantry plane. Radiation dose to the operator was higher with CT fluoroscopy, and patient radiation dose was higher with EMN. Further study with a wider array of procedures and anatomic locations is warranted.     

Double-Needle Lavage for Effective Treatment of Difficult-Aspiration Thyroid Cystic Nodules: A Single-Center Controlled Trial

PurposeTo explore the safety and efficacy of double-needle lavage (DNL) in the treatment of difficult aspiration thyroid cystic nodules.Materials and MethodsThis single-center, prospective, randomized controlled trial was conducted using 100 thyroid cysts from 100 patients who were treated in our hospital from January 2018 to August 2019. These patients were placed into 2 groups; group A including 40 patients treated with single-needle aspiration (SNA), and group B including 60 patients treated with DNL. The safety and efficacy of these 2 aspiration methods were compared.ResultsTen patients in group A that did not benefit from SNA were transferred to group B. No complication occurred in either group. Notably, DNL showed significantly higher efficacy than SNA. This was evidenced by the higher extraction rate of materials in the capsule (A vs B, 91 ± 6.51% vs 98.45 ± 1.74%, P < .001) and overall nodule volume reduction rate in group B (A vs B, 87.54 ± 7.84% vs 95.62 ± 3.66%, P < .001). In group B, patients who received DNL treatment with 2 needles pointed at the upper and lower extremes of the cystic nodules (B2) exhibited significantly better aspiration effects compared to patients in which the 2 needles were pointed at the same ultrasound plane (B1) (P < .05), especially for patients with maximum diameter of nodules ≥3 cm (P < .01).ConclusionsDNL treatment could efficiently and safely replace cystic material from thyroid gland. Moreover, our results indicate that DNL treatment in which 2 needles are pointed at the 2 extremes of cystic nodules yields higher efficacy in patients with maximum diameter of nodules ≥3 cm.     

Efficacy and Safety of Ultrasound-Guided Supraclavicular Brachial Plexus Block during Angioplasty of Dysfunctional Arteriovenous Access: A Prospective,Randomized Single-Center Clinical Trial

PurposeTo evaluate the efficacy and safety of the ultrasound-guided supraclavicular brachial plexus block (BPB) during angioplasty of dysfunctional arteriovenous access.Materials and MethodsEighty study participants with dysfunctional arteriovenous access were enrolled in this prospective, randomized clinical trial between November 2016 and February 2018. Eighty patients were randomized to either the ultrasound-guided supraclavicular BPB group (mean age ± standard deviation [SD], 65.1 ± 12.4; male:female = 17:23) or the no regional anesthesia group (mean age ± SD, 64.0 ± 11.7; male:female = 25:15). Pain was assessed on the 10-point Visual Analogue Scale. Participant satisfaction was examined. Six-month clinical follow-up was done to evaluate arteriovenous access patency and long-term complications.ResultsThe BPB group showed a lower average pain score than the control group (mean ± SD, 0.9 ± 1.9 vs 6.4 ± 2.5; P < .001). Participant satisfaction (mean ± SD, 2.8 ± 0.5 vs 2.1±0.8; P < .001) was also higher in the BPB group. Six-month patency was 65% (26/40) in the BPB group and 59% (23/39) in the control group, with no significant difference between the 2 groups (P = .59). No major immediate or delayed complications were observed.ConclusionsUltrasound-guided BPB is highly effective in reducing pain during angioplasty of dysfunctional arteriovenous access with an acceptable safety profile.     

Preliminary Study of Microwave Ablation for Multifocal Papillary Thyroid Microcarcinoma in Nonoperative Candidates

PurposeTo study the feasibility, safety, and effectiveness of microwave ablation (MWA) in patients with multifocal papillary thyroid microcarcinoma (PTMC).Materials and MethodsThis retrospective study included patients who underwent MWA for multifocal PTMC (number of nodules ≤3). A total of 44 patients were included, and the mean age was 43 years (SD ± 11). After ablation, progression-free survival (PFS) at 6, 12, 24, 36, and 48 months; disease progression; change in tumor size and volume; tumor disappearance rate; and adverse events (AEs) were assessed, and the feasibility, safety, and effectiveness of MWA for PTMC were evaluated on the basis of statistical analysis.ResultsThe median follow-up period was 18 months (interquartile range, 12–33 months). The PFS rates at 6, 12, 24, 36, and 48 months were 100.0%, 96.4%, 96.4%, 70.3%, and 52.7%, respectively. The disease progression rate was 11.4% (5 of 44 patients). The maximum diameter (MD) and volume of the ablation zone were larger at the 3-month follow-up than before ablation (median MD, 13.0 vs 7.0 mm; P < .001; median volume, 503.8 vs 113.0 mm³; P < .001). Subsequently, the tumors exhibited a reduction in both size and volume after 18 months (median MD, 4.0 vs 7.0 mm; P = .04; median volume, 12.6 vs 113.0 mm³; P = .055). At the end of the follow-up period, the complete response rate was 59% (26 of 44 patients). The overall AE rate was 6.8%.ConclusionsMWA is a feasible treatment for PTMC (number of nodules ≤3), and this study preliminarily demonstrated the safety and effectiveness of this technique.     

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.