IN.PACT AV Access Trial: Economic Evaluation of Drug-Coated Balloon Treatment for Dysfunctional Arteriovenous Fistulae Based on 12-Month Clinical Outcomes

PurposeTo study, from a U.S. payer’s perspective, the economic consequences of drug-coated balloon (DCB) versus standard percutaneous transluminal angioplasty (PTA) use for the treatment of stenotic lesions in dysfunctional hemodialysis arteriovenous fistulae.Materials and MethodsCost differences between DCBs and PTA at year 1 and beyond were calculated via 2 methods. The first approach used the mean absolute number of trial-observed access circuit reinterventions through 12 months (0.65 ± 1.05 vs 1.05 ± 1.18 events per patient for DCBs and PTA, respectively) and projected treatment outcomes to 3 years. The second approach was based on the trial-observed access circuit primary patency rates at 12 months (53.8% vs 32.4%) and calculated the cost difference on the basis of previously published Medicare cost for patients who maintained or did not maintain primary patency. Assumptions regarding DCB device prices were tested in sensitivity analyses, and the numbers needed to treat were calculated.ResultsUsing the absolute number of access circuit reinterventions approach, the DCB strategy resulted in an estimated per-patient savings of $1,632 at 1 year and $4,263 at 3 years before considering the DCB device cost. The access circuit primary patency approach was associated with a per-patient cost savings of $2,152 at 1 year and $3,894 at 2.5 years of follow-up. At the theoretical DCB device reimbursement of $1,800, savings were $1,680 and $2,049 at 2.5 and 3 years, respectively. The one-year NNT of DCB compared to PTA was 2.48.ConclusionsEndovascular therapy for arteriovenous access stenosis with the IN.PACT AV DCB can be expected to be cost-saving if longer follow-up data confirm its clinical effectiveness.     

MRI as First Line Imaging for Suspected Acute Appendicitis during Pregnancy: Diagnostic Accuracy and level of Inter-Radiologist Agreement

ObjectiveEvaluation of acute appendicitis (AA) in pregnancy is supported with diagnostic imaging. Typically, ultrasound (US) is performed first, and then often followed by magnetic resonance imaging (MRI) due to continued diagnostic uncertainty. The purpose of our study was to evaluate the sensitivity, specificity, and accuracy of US as compared to MRI and to evaluate the inter-radiologist agreement amongst body Radiologists with varying levels of expertise.Materials and MethodsWe performed a retrospective study of 364 consecutive pregnant patients with clinical suspicion of AA at a single center over a 6-year period. Sensitivity, Specificity, accuracy, positive and negative predictive values were calculated for US and MRI. Inter Radiologist agreement was determined using Cohen's Kappa analysis between original interpreting Radiologist and retrospective review by expert Radiologist.ResultsThirty-one of 364 patients (8.5%) underwent appendectomy based on preoperative diagnosis, with confirmation of acute appendicitis (AA) by pathology in 19. US was able to visualize the appendix in only 6 (1.65%), 5 of whom had appendicitis. 141 patients underwent MRI, and correctly diagnosed appendicitis in 9. No patient with a negative MRI diagnosis had AA. The sensitivity, and negative predictive value for diagnosing AA with MRI was 100%. The MRI inter-reader agreement for appendix visualization and overall accuracy were 87.9 and 98% with Cohen Kappa of 0.7 and 0.56 respectively.ConclusionsOur data suggests that MRI should be considered the first line imaging modality in pregnant patients suspected of having AA. Body Radiologists with varied levels of experience in MRI readouts had substantial agreement.     

Fully Integrated Laser Guidance for CT-Based Punctures: A Study in Phantoms and Patients

PurposeTo test the hypothesis of equal or even superior applicability and accuracy of a fully integrated, laser-based computed tomography (CT) navigation system compared with conventional CT guidance for percutaneous interventions.Materials and MethodsCT-guided punctures were first performed in phantoms. Four radiologists with different experience levels (2 residents (L.B., C.D.) and 2 board-certified radiologists (B.M., K.R.) performed 48 punctures using both conventional image-guided and laser-guided approaches. Subsequently, 12 punctures were performed in patients during a clinical pilot trial. Phantom targets required an in-plane or a single-/double-angulated, out-of-plane approach. Planning and intervention time, control scan number, radiation exposure, and accuracy of needle placement (measured by deviation of the needle tip to the designated target) were assessed for each guidance technique and compared (Mann-Whitney U test and t test). Patient interventions were additionally analyzed for applicability in a clinical setting.ResultsThe application of laser guidance software in the phantom study and in 12 human patients in a clinical setting was both technically and clinically feasible in all cases. The mean planning time (P = .009), intervention time (P = .005), control scan number (P < .001), and radiation exposure (P = .013) significantly decreased for laser-navigated punctures compared with those for conventional CT guidance and especially in punctures with out-of-plane-trajectories. The accuracy significantly increased for laser-guided interventions compared with that for conventional CT (P < .001).ConclusionsInterventional radiologists with differing levels of experience performed faster and more accurate punctures for out-of-plane trajectories in the phantom models, using a new, fully integrated, laser-guided CT software and demonstrated excellent clinical and technical success in initial clinical experiments.     

Comparing Radiomics features of tumour and healthy liver tissue in a limited CT dataset: A machine learning study

IntroductionLiver cancer lesions on Computed Tomography (CT) withholds a great amount of data, which is not visible to the radiologists and radiographer. Radiomics features can be extracted from the lesions and used to train Machine Learning (ML) algorithms to predict between tumour and liver tissue. The purpose of this study was to investigate and classify Radiomics features extracted from liver tumours and normal liver tissue in a limited CT dataset.MethodsThe Liver Tumour Segmentation Benchmark (LiTS) dataset consisting of 131 CT scans of the liver with segmentations of tumour tissue and healthy liver was used to extract Radiomic features. Extracted Radiomic features included size, shape, and location extracted with morphological and statistical techniques according to the International Symposium on Biomedical Imaging manual. Relevant features was selected with chi2 correlation and principal component analysis (PCA) with tumour and healthy liver tissue as outcome according to a consensus between three experienced radiologists. Logistic regression, random forest and support vector machine was used to train and validate the dataset with a 10-fold cross-validation method and the Grid Search as hyper-parameter tuning. Performance was evaluated with sensitivity, specificity and accuracy.ResultsThe performance of the ML algorithms achieved sensitivities, specificities and accuracy ranging from 96.30% (95% CI: 81.03%–99.91%) to 100.00% (95% CI: 86.77%–100.00%), 91.30% (95% CI: 71.96%–98.93%) to 100.00% (95% CI: 83.89%–100.00%)and 94.00% (95% CI: 83.45%–98.75%) to 100.00% (95% CI: 92.45%–100.00%), respectively.ConclusionML algorithms classifies Radiomics features extracted from healthy liver and tumour tissue with perfect accuracy. The Radiomics signature allows for a prognostic biomarker for hepatic tumour screening on liver CT.Implications for practiceDifferentiation between tumour and liver tissue with Radiomics ML algorithms have the potential to increase the diagnostic accuracy, assist in the decision-making of supplementary multiphasic enhanced medical imaging, as well as for developing novel prognostic biomarkers for liver cancer patients.     

Validation of clinical photography and a laser fluorescence device for assessment of enamel demineralization during multi-bracketed fixed orthodontic treatment

AimTo compare the validity of DIAGNOdent pen™ 2190 and clinical photographs in the diagnosis (presence or absence) and assessment of white spot lesions (WSLs) during multi-bracketed fixed orthodontic treatment.MethodsA total of 1607 readings from 99 patients were obtained using DIAGNOdent pen™ 2190, clinical photographs, and visual assessment criteria to assess WSLs at 6 -, 12- and 18 months after bonding of brackets. Receiver operating characteristic curves were constructed, and areas under the curve (AUC) were calculated to assess the presence or absence of WSLs and distinguish the severity of WSLs as slight or severe. Sensitivities, specificities, and AUC were calculated for outcomes at an alpha of 0.05 and 95% confidence intervals (CIs).ResultsThe values of sensitivity and specificity of DIAGNOdent pen™ 2190 were found to be 0.78 and 0.83, respectively, to distinguish presence/absence of WSLs with good accuracy (AUC= 0.855; 95% CI: 0.820–0.889) and for digital photographs, accuracy was excellent (AUC= 0.973, 95% CI: 0.956–0.991) with sensitivity and specificity of 0.96 and 0.99, respectively. However, the accuracy of DIAGNOdent pen™ 2190 was poor (AUC= 0.543, 95% CI: 0.418–0.668) in delineating slight and severe WSLs with a sensitivity of 0.31 and specificity of 0.83; while the values of sensitivity and specificity for distinguishing slight or severe lesions for clinical photographs were 0.96 and 0.99, respectively with excellent accuracy (AUC=0.978, 95% CI: 0.936–1.000).ConclusionsClinical photographs had better validity than DIAGNOdent pen™ 2190 in diagnosis and assessment of severity of demineralized lesions during multi-bracketed fixed orthodontic treatment.     

The effect of different statistical approaches on image quality data obtained from radiological examinations

IntroductionSelection of optimal image acquisition protocols in medical imaging remains a grey area, the superimposed use of the Likert scale in radiological image quality evaluations creates an additional challenge for the statistical analysis of image quality data.Using a simulation study, we have trialled a novel approach to analysing radiological image quality Likert scale data.MethodsA simulation study was undertaken where simulated datasets were generated based on the distribution of Likert scale values according to varying image acquisition protocols from a real dataset. Simulated Likert scale values were pooled in four different ways; the mean, median, mode and the summation of patient Likert scale values of which the total was assigned a categorical Likert scale value. Estimates of bias, MAPE and RMSPE were then calculated for all four pooling approaches to determine which method most accurately represented an expert's opinion.ResultsWhen compared to an expert's opinion, the method of summation and categorisation of Likert scale values was most accurate 49 times out of the 114 (43.0%) tests. The mean 28 times out of 114 (24.6%), the median 23 times out of 114 (20.2%) and the mode 17 times out of 114 (14.9%).ConclusionWe conclude that our method of summation and categorisation of Likert scale values is most often the best representation of the simulated data compared to the expert's opinion.Implications for practiceThere is scope to reproduce this simulation study with multiple observers to reflect clinical reality more accurately with the dynamic nature of multiple observers. This also prompts future investigation into other anatomical areas, to see if the same methods produce similar results.     

Radiation-Free Thoracic Endovascular Aneurysm Repair with Fiberoptic and Electromagnetic Guidance: A Phantom Study

PurposeTo evaluate the feasibility and accuracy of a radiation-free implantation of a thoracic aortic stent graft employing fiberoptic and electromagnetic tracking in an anthropomorphic phantom.Materials and MethodsAn anthropomorphic phantom was manufactured based on computed tomography (CT) angiography data from a patient. An aortic stent graft application system was equipped with a fiber Bragg gratings and 3 electromagnetic sensors. The stent graft was navigated in the phantom by 3 interventionalists using the tracking data generated by both technologies. One implantation procedure was performed. The technical success of the procedure was evaluated using digital subtraction angiography and CT angiography (before and after the intervention). Tracking accuracy was determined at various anatomical landmarks based on separately acquired fluoroscopic images. The mean/maximum errors were measured for the stent graft application system and the tip/end of the stent graft.ResultsThe procedure resulted in technical success with a mean error below 3 mm for the entire application system and <2 mm for the position of the tip of the stent graft. Navigation/implantation and handling of the device were rated sufficiently accurate and on par with comparable, routinely used stent graft application systems.ConclusionsThe study demonstrates successful stent graft implantation during a thoracic endovascular aortic repair procedure employing advanced guidance techniques and avoiding fluoroscopic imaging. This is an essential step in facilitating the implantation of stent grafts and reducing the health risks associated with ionizing radiation during endovascular procedures.     

Five-Year Outcomes of the Bioresorbable Peripheral Remedy Stent in the Treatment of Iliac Artery Disease

PurposeTo evaluate the 5-year performance of a bioresorbable vascular scaffold, the Remedy stent, for the treatment of iliac artery atherosclerotic disease.Materials and MethodsThis prospective, multicenter, single-arm clinical study evaluated 97 patients (97 lesions) with symptomatic TransAtlantic Inter-Society Consensus II A/B iliac artery lesions for 5 years after stent placement. The primary efficacy end point was 12-month primary patency compared with the prespecified standard derived from historical data with metallic stents, and the primary safety end point was the occurrence of major adverse clinical events within 5 years. All angiographic and computed tomography angiographic findings were evaluated by an independent core laboratory for quantitative vessel analysis.ResultsThe 12-month primary patency rate was 88.6% (95% CI, 80.1%–94.4%), which was lower than the prespecified standard. No significant difference was noted between the diameter stenosis at 9 and 12 months. There were no device- or procedure-related deaths, major amputation, or distal embolization during the follow-up period. The ankle-brachial index maintained significant improvement through the 5-year period compared with that at baseline. The Kaplan–Meier estimates of freedom from target lesion revascularization (TLR), major adverse cardiovascular events, and major adverse cardiovascular and limb events were 95.8%, 91.7%, and 87.5% at 12 months and 85.4%, 72.1%, and 62.5% at 5 years, respectively.ConclusionsThe 5-year follow-up outcomes, including freedom from TLR, of the Remedy stent in iliac artery lesions were satisfactory, with a good safety profile. Nevertheless, the 12-month primary patency did not meet the expected standard compared with that of contemporary metallic stents.     

Impact of Chemoembolic Regimen on Immune Cell Recruitment and Immune Checkpoint Marker Expression following Transcatheter Arterial Chemoembolization in a VX2 Rabbit Liver Tumor Model

PurposeTo characterize the effects of commonly used transcatheter arterial chemoembolization (TACE) regimens on the immune response and immune checkpoint marker expression using a VX2 rabbit liver tumor model.Materials and MethodsTwenty-four VX2 liver tumor-bearing New Zealand white rabbits were assigned to 7 groups (n = 3 per group) undergoing locoregional therapy as follows: (a) bicarbonate infusion without embolization, (b) conventional TACE (cTACE) using a water-in-oil emulsion containing doxorubicin mixed 1:2 with Lipiodol, drug-eluting embolic-TACE with either (c) idarubicin-eluting Oncozene microspheres (40 μm) or (d) doxorubicin-eluting Lumi beads (40–90 μm). For each therapy arm (b–d), a tandem set of 3 animals with additional bicarbonate infusion before TACE was added, to evaluate the effect of pH modification on the immune response. Three untreated rabbits served as controls. Tissue was harvested 24 hours after treatment, followed by digital immunohistochemistry quantification (counts/μm² ± SEM) of tumor-infiltrating cluster of differentiation 3⁺ T-lymphocytes, human leukocyte antigen DR type antigen-presenting cells (APCs), cytotoxic T-lymphocyte–associated protein-4 (CTLA-4), and programmed cell death protein-1 (PD-1)/PD-1 ligand (PD-L1) pathway axis expression.ResultsLumi-bead TACE induced significantly more intratumoral T-cell and APC infiltration than cTACE and Oncozene-microsphere TACE. Additionally, tumors treated with Lumi-bead TACE expressed significantly higher intratumoral immune checkpoint markers compared with cTACE and Oncozene-microsphere TACE. Neoadjuvant bicarbonate demonstrated the most pronounced effect on cTACE and resulted in a significant increase in intratumoral cluster of differentiation 3⁺ T-cell infiltration compared with cTACE alone.ConclusionsThis preclinical study revealed significant differences in evoked tumor immunogenicity depending on the choice of chemoembolic regimen for TACE.     

Intravascular Ultrasound-Guided Transvenous Biopsy of Abdominal and Pelvic Targets Difficult to Access by Percutaneous Needle Biopsy: Technique and Initial Clinical Experience

PurposeTo report initial clinical experience with intravascular ultrasound (US)-guided transvenous biopsy (TVB) for perivascular target lesions in the abdomen and pelvis using side-viewing phased-array intracardiac echocardiography catheters.Materials and MethodsIn this single-institution, retrospective study, 48 patients underwent 50 intravascular US-guided TVB procedures for targets close to the inferior vena cava or iliac veins deemed difficult to access by conventional percutaneous needle biopsy (PNB). In all procedures, side-viewing phased-array intracardiac echocardiography intravascular US catheters and transjugular liver biopsy sets were inserted through separate jugular or femoral vein access sheaths, and 18-gauge core needle biopsy specimens were obtained under real-time intravascular US guidance. Diagnostic yield, diagnostic accuracy, and complications were analyzed.ResultsIntravascular US-guided TVB was diagnostic of malignancy in 40 of 50 procedures for a diagnostic yield of 80%. There were 5 procedures in which biopsy was correctly negative for malignancy, with a per-procedure diagnostic accuracy of 90% (45/50). Among the 5 false negatives, 2 patients underwent repeat intravascular US-guided TVB, which was diagnostic of malignancy for a per-patient diagnostic accuracy of 94% (45/48). There were 1 (2%) mild, 2 (4%) moderate, and 1 (2%) severe adverse events, with 1 moderate severity adverse event (venous thrombosis) directly attributable to the intravascular US-guided TVB technique.ConclusionsIntravascular US-guided TVB performed on difficult-to-approach perivascular targets in the abdomen and pelvis resulted in a high diagnostic accuracy, similar to accepted thresholds for PNB. Complication rates may be slightly higher but should be weighed relative to the risks of difficult PNB, surgical biopsy, or clinical management without biopsy.     

Intravascular Ultrasound-Guided Transvenous Biopsy of Retroperitoneal Lymph Nodes: Diagnostic Accuracy and Safety Compared with CT-Guided Percutaneous Biopsy

PurposeTo compare the diagnostic accuracy and adverse event rates of intravascular ultrasound (US)-guided transvenous biopsy (TVB) versus those of computed tomography (CT)-guided percutaneous needle biopsy (PNB) for retroperitoneal (RP) lymph nodes.Materials and MethodsIn this single-institution, retrospective study, 32 intravascular US-guided TVB procedures and a sample of 34 CT-guided PNB procedures for RP lymph nodes where targets were deemed amenable to intravascular US-guided TVB were analyzed. Procedural metrics, including diagnostic accuracy, defined as diagnostic of malignancy or a clinically verifiable benign result, and adverse event rates were compared.ResultsThe targets of intravascular US-guided TVB were primarily aortocaval (47%, 15/32) or precaval (34%, 11/32), whereas those of CT-guided PNB were primarily right pericaval (44%, 15/34) or retrocaval (44%, 15/34) (P < .001). The targets of intravascular US-guided TVB averaged 2.4 cm in the long axis (range, 1.3–3.7 cm) compared with 2.9 cm (range, 1.4–5.7 cm) for those of CT-guided PNB (P = .02). There was no difference in the average number of needle passes (3.8 for intravascular US-guided TVB vs 3.9 for CT-guided PNB; P = .68). The diagnostic accuracy was 94% (30/32) and the adverse event rate was 3.1% (1/32) for intravascular US-guided TVB, similar to those of CT-guided PNB (accuracy, 91% [31/34]; adverse event rate, 2.9% [1/34]).ConclusionsIntravascular US-guided TVB had a diagnostic accuracy and adverse event rate similar to CT-guided PNB for RP lymph nodes, indicating that intravascular US-guided TVB may be as safe and effective as conventional biopsy approaches for appropriately selected targets.     

Deep Learning Based on MR Imaging for Predicting Outcome of Uterine Fibroid Embolization

PurposeTo develop and validate a deep learning model based on routine magnetic resonance (MR) imaging obtained before uterine fibroid embolization to predict procedure outcome.Materials and MethodsClinical data were collected on patients treated with uterine fibroid embolization at the Hospital of the University of Pennsylvania from 2007 to 2018. Fibroids for each patient were manually segmented by an abdominal radiologist on a T1-weighted contrast-enhanced (T1C) sequence and a T2-weighted sequence of MR imaging obtained before and after embolization. A residual convolutional neural network (ResNet) model to predict clinical outcome was trained using MR imaging obtained before the procedure.ResultsInclusion criteria were met by 727 fibroids in 409 patients. At clinical follow-up, 85.6% (n = 350) of 409 patients (590 of 727 fibroids; 81.1%) experienced symptom resolution or improvement, and 14.4% (n = 59) of 409 patients (137 of 727 fibroids; 18.9%) had no improvement or worsening symptoms. The T1C trained model achieved a test accuracy of 0.847 (95% confidence interval [CI], 0.745–0.914), sensitivity of 0.932 (95% CI, 0.833–0.978), and specificity of 0.462 (95% CI, 0.232–0.709). In comparison, the average of 4 radiologists achieved a test accuracy of 0.722 (95% CI, 0.609–0.813), sensitivity of 0.852 (95% CI, 0.737–0.923), and specificity of 0.135 (95% CI, 0.021–0.415).ConclusionsThis study demonstrates that deep learning based on a ResNet model achieves good accuracy in predicting outcome of uterine fibroid embolization. If further validated, the model may help clinicians better identify patients who can most benefit from this therapy and aid clinical decision making.     

Image-Guided Percutaneous Needle Biopsy for Benign and Malignant Bone Tumors: Systematic Review and Meta-Analysis

PurposeTo compare the diagnostic yield and accuracy of both image-guided core-needle biopsy (CNB) and fine-needle biopsy and evaluate the benefit of performing fine-needle biopsy in addition to CNB in patients with suspected benign and malignant bone tumors.Materials and MethodsA systematic search was performed on March 10, 2021, to determine whether fine-needle aspiration (FNA) plays any role when performed alone or in combination with CNB. The included studies were aggregated for the pooled estimates of diagnostic yield and histologic accuracy of image-guided percutaneous needle biopsy of bone tumors. Twenty-nine studies published between 1996 and 2021 were included.ResultsWhen all patients with bone tumors were included, the rates of diagnostic yield and accuracy of FNA and CNB were 88.5% and 82.5% and 91.4% and 92.7%, respectively; the rates of both the methods combined were 96.5% and 94.1%, respectively; and for the lytic subgroup, the rates of diagnostic yield and accuracy of CNB and both the methods combined were 94.3% and 100% and 98.9% and 90.4%, respectively. A P value of <.05 was considered statistically significant.ConclusionThe present meta-analysis showed that core biopsy alone outperformed fine-needle biopsy alone in all categories of benign and malignant tumors. Additionally, the diagnostic yield was improved when FNA was used in addition to CNB for lytic bone lesions.     

Quantification of Blood Flow in Dialysis Access Using Custom-Acquisition Protocol and Imaging Methods: A Clinical Validation Study

PurposeTo determine access blood flow (ABF) rate using 2D image sequences acquired with digital subtraction angiography (DSA) and fluoroscopy.Materials and MethodsA total of 23 patients with known or suspected malfunctioning accesses were imaged using 2 filming modes: DSA at 3 or 6 frames/s (F/s), and fluoroscopy at 10 or 15 pulses/s (P/s). ABF rates were quantified using a bolus tracking method based on cross-correlation algorithm and compared with catheter-based thermal dilution (TD) flow measurements. The indicator-dilution curves were fitted with a gamma-variate (GV) curve fitting model to assess the effect on accuracy. Radiation doses were calculated to examine any increased susceptibility to tissue reactions and stochastic effects.ResultsFor DSA images, the absolute percent deviations (mean ± standard error of mean) in computed flow vs TD flow measurements at 3 F/s and 6 F/s were 34% ± 4.5% and 20% ± 4.7%, respectively, without curve fitting, and 31% ± 3.3% and 20% ± 4.1%, respectively, with curve fitting. For fluoroscopic images, the deviations at 10 P/s and 15 P/s were 44% ± 7.3% and 68% ± 10.7%, respectively, without curve fitting and 36% ± 6.4% and 48% ± 7.1%, respectively, with curve fitting. The mean peak skin dose and effective dose at 6 F/s were 3.28 mGy and 75 μSv, respectively.ConclusionsDigital subtraction angiography images obtained at 6 F/s offered the highest accuracy for dialysis access blood flow quantification.     

Prediction of the response to photodynamic therapy in patients with chronic central serous chorioretinopathy based on optical coherence tomography using deep learning

PurposeTo assess the prediction of the response to photodynamic therapy (PDT) in chronic central serous chorioretinopathy (CSCR) based on spectral-domain optical coherence tomography (SD-OCT) images using deep learning (DL).MethodsRetrospective study including 216 eyes of 175 patients with CSCR and persistent subretinal fluid (SRF) who underwent half-fluence PDT. SD-OCT macular examination was performed before (baseline) and 3 months after treatment. Patients were classified into groups by experts based on the response to PDT: Group 1, complete SRF resorption (n = 100); Group 2, partial SRF resorption (n = 66); and Group 3, absence of any SRF resorption (n = 50). This work proposes different computational approaches: 1st approach compares all groups; 2nd compares groups 1 vs. 2 and 3 together; 3rd compares groups 2 vs. 3.ResultsThe mean age was 55.6 ± 10.9 years and 70.3% were males. In the first approach, the algorithm showed a precision of up to 57% to detect the response to treatment in group 1 based on the initial scan, with a mean average accuracy of 0.529 ± 0.035. In the second model, the mean accuracy was higher (0.670 ± 0.046). In the third approach, the algorithm showed a precision of 0.74 ± 0.12 to detect the response to treatment in group 2 (partial SRF resolution) and 0.69 ± 0.15 in group 3 (absence of SRF resolution).ConclusionDespite the high clinical variability in the response of chronic CSCR to PDT, this DL algorithm offers an objective and promising tool to predict the response to PDT treatment in clinical practice.     

The Retrograde Basilic Approach for Balloon-Assisted Maturation of Brachiocephalic Arteriovenous Fistulas

PurposeTo assess the feasibility and outcomes of an approach utilizing transbasilic access for balloon-assisted maturation (BAM) of brachiocephalic arteriovenous fistulas (BCAVFs).Materials and MethodsThis retrospective analysis comprised 28 patients (mean age, 63 years ± 10.8) who underwent endovascular treatment of their immature BCAVFs via a basilic approach from December 2016 to December 2018. The mean age of the BCAVFs was 3.3 months ± 1.4 at the time of BAM. Other demographic data, vascular access characteristics, procedural data, technical and clinical success rates, and adverse events were also evaluated.ResultsAll patients had inflow juxta-anastomotic stenoses, with 4 patients (14%) having concomitant outflow tract stenoses and 1 patient (4%) having a short-segment occlusion at the stenotic juxta-anastomotic segment. Technical success was achieved in 27 patients (96%). The mean diameter of the largest balloon used was 5.7 mm ± 0.6. Clinical success was achieved in 22 patients (79%), with 6 patients (21%) requiring a subsequent additional intervention before successful cannulation. No perioperative adverse events were observed.ConclusionsThe retrograde basilic approach is feasible, safe, and effective for BAM of BCAVFs.     

Influence of coronary stenosis location on diagnostic performance of machine learning-based fractional flow reserve from CT angiography

BackgroundCompared with invasive fractional flow reserve (FFR), coronary CT angiography (cCTA) is limited in detecting hemodynamically relevant lesions. cCTA-based FFR (CT-FFR) is an approach to overcome this insufficiency by use of computational fluid dynamics. Applying recent innovations in computer science, a machine learning (ML) method for CT-FFR derivation was introduced and showed improved diagnostic performance compared to cCTA alone. We sought to investigate the influence of stenosis location in the coronary artery system on the performance of ML-CT-FFR in a large, multicenter cohort.MethodsThree hundred and thirty patients (75.2% male, median age 63 years) with 502 coronary artery stenoses were included in this substudy of the MACHINE (Machine Learning Based CT Angiography Derived FFR: A Multi-Center Registry) registry. Correlation of ML-CT-FFR with the invasive reference standard FFR was assessed and pooled diagnostic performance of ML-CT-FFR and cCTA was determined separately for the following stenosis locations: RCA, LAD, LCX, proximal, middle, and distal vessel segments.ResultsML-CT-FFR correlated well with invasive FFR across the different stenosis locations. Per-lesion analysis revealed improved diagnostic accuracy of ML-CT-FFR compared with conventional cCTA for stenoses in the RCA (71.8% [95% confidence interval, 63.0%–79.5%] vs. 54.8% [45.7%–63.8%]), LAD (79.3 [73.9–84.0] vs. 59.6 [53.5–65.6]), LCX (84.1 [76.0–90.3] vs. 63.7 [54.1–72.6]), proximal (81.5 [74.6–87.1] vs. 63.8 [55.9–71.2]), middle (81.2 [75.7–85.9] vs. 59.4 [53.0–65.6]) and distal stenosis location (67.4 [57.0–76.6] vs. 51.6 [41.1–62.0]).ConclusionIn a multicenter cohort with high disease prevalence, ML-CT-FFR offered improved diagnostic performance over cCTA for detecting hemodynamically relevant stenoses regardless of their location.     

Minimally Invasive Image-Guided Ablation,Osteoplasty, Reinforcement,and Internal Fixation (AORIF) for Osteolytic Lesions in the Pelvis and Periarticular Regions of Weight-Bearing Bones

PurposeTo assess early outcome, safety, and complications of an alternative to open surgical treatments of osteolytic lesions in periarticular load-bearing bones.Materials and MethodsA single-center, prospective clinical cohort study of 26 lesions in 23 consecutive patients with painful osteolytic skeletal lesions was performed. Patients were followed for an average of 7 mo (1–18 mo). Lesions were targeted from the most intact bone via minimally invasive percutaneous approach for stable anchorage of internal fixation screws using fluoroscopic guidance. Cannulated screws served as universal portals for ablation, balloon osteoplasty, and delivery of bone cement in addition to internal fixation for cement anchoring and prophylactic stabilization of uninvolved bone.ResultsThere were 19 osteolytic lesions in the pelvis, 4 in the proximal femur, 2 in the proximal tibia, and 1 in the calcaneus. All defects were associated with severe pain or fractures. There were no conversions to open surgery and no infection or bleeding requiring transfusion, embolization, or additional procedures. There was significant improvement in visual analogue scale (VAS) pain score from 8.32 ± 1.70 to 2.36 ± 2.23, combined pain and functional ambulation score from 4.48 ± 2.84 to 7.28 ± 2.76, and Musculoskeletal Tumor Society score from 45% to 68% (P < .05).ConclusionsAblation, osteoplasty, reinforcement, and internal fixation is a safe and effective minimally invasive percutaneous image-guided treatment option for functional improvement or palliation of painful osteolytic lesions in the pelvis and periarticular loadbearing bones.     

Retrograde Pedal Access via Occluded Arteries in Endovascular Treatment of Critical Limb Ischemia

PurposeTo evaluate the feasibility and technical outcomes of retrograde access via occluded pedal arteries in endovascular treatment of critical limb ischemia (CLI) when the conventional antegrade approach fails.Materials and MethodsOne hundred fifty-one patients with CLI (age 69 y ± 10.5; 116 men) who were not surgical candidates and were treated via retrograde pedal access between January 2016 and January 2018 were evaluated retrospectively. Seventy patients in whom retrograde access was performed through occluded arteries constituted the occluded group, and 81 patients who were treated via retrograde access from patent arteries constituted the nonoccluded group. Pedal access success, lesion crossing success, angiographic success, overall technical success, and procedure-related complications were evaluated and compared between groups.ResultsPedal access success (74 of 78 vs 83 of 87 attempts; P = .873) and lesion crossing success (64 of 78 vs 77 of 87 lesions; P = .340) were comparable between subgroups. Angiographic success (54 of 78 vs 77 of 87 lesions; P = .012) and overall technical success (48 of 70 vs 72 of 81 patients; P = .004) rates were lower in the occluded group. Procedure-related complications were similar between groups (P = .096).ConclusionsRetrograde pedal access from occluded pedal arteries is a feasible option when an antegrade approach fails in endovascular treatment of CLI. Although it has lower technical success, its use enables angiosome-directed therapy and has the potential to improve the outcomes of the procedure.     

Assessment of 3-Year Patency after Endoluminal versus Surgical Bypass Therapy for Complex Femoropopliteal Artery Disease

PurposeTo compare the 3-year clinical outcomes of endoluminal bypass with those of surgical bypass for complex femoropopliteal (FP) arterial lesions.Materials and MethodsIn this retrospective multicenter study, 530 patients with symptomatic peripheral artery disease (Rutherford classification 1–3, 66.0%; 4–6, 34.0%) who underwent either endoluminal bypass with Viabahn stent grafts (n = 276) or surgical bypass (n = 254) (with saphenous vein grafts, 74.4%; prosthetic grafts, 25.6%) for FP arterial lesions between 2010 and 2018 were analyzed. The propensity score-matched analysis was performed to compare the 3-year clinical outcomes of endoluminal bypass with those of surgical bypass. The primary end point was primary patency (freedom from restenosis). The secondary end points were secondary patency, freedom from target lesion revascularization (TLR), limb salvage, and overall survival. The interaction effect of baseline characteristics on the association of the revascularization strategy with the risk of restenosis was analyzed using the Poisson mixed-effect model.ResultsThe propensity score-matched analysis extracted 107 pairs. After propensity score matching, the primary patency rate at 1, 2, and 3 years was 84.5%, 75.1%, and 70.9%, respectively, for the endoluminal bypass group versus 78.6%, 73.3%, and 72.0%, respectively, for the surgical bypass group (P = .65). There was no significant difference in secondary patency, freedom from TLR, limb salvage, and overall survival (all P > .05). The subsequent interaction analysis revealed that the involvement of popliteal lesions, small distal reference vessel diameters, and long lesions favored surgical bypass over endoluminal bypass because of improved primary patency (all P for interaction < .05).ConclusionsThe 3-year clinical outcomes after endoluminal bypass or surgical bypass for FP arterial lesions were similar.