Faculty Bibliography

Genicular artery embolization is increasingly recognized as a safe and effective treatment option for symptomatic knee osteoarthritis and recurrent hemarthrosis following total knee arthroplasty. Genicular arteries are an essential vascular supply for the knee joint and demonstrate considerable variability. Familiarity with the anatomy and common variations is critical for pre-procedural planning, accurate target selection, and minimizing adverse events in trans-arterial embolization procedures. This review aims to provide a detailed discussion of the genicular artery anatomy that is relevant to interventional radiologists performing genicular artery embolization.

PURPOSE/OBJECTIVE:To characterize how the adoption of virtual residency interviews (2020-2021 cycle) has impacted the geographic distribution of radiology resident matches. METHODS:University-based interventional (IR) and diagnostic radiology (DR) residency programs from 2017 to 2021 were identified using a national residency database (FRIEDA). Public applicant data were obtained from official residency program websites. Medical schools and residency programs were categorized by US census regions. Geographic applicant distribution before and after the initiation of virtual interviews was statistically assessed using Chi-square tests. The effect of virtual interviews on the probability of matching within the same geographic region as one's medical school was evaluated with multivariate logistic regression. RESULTS:4358 radiology residents (88% diagnostic, 12% interventional) matched at 102 radiology programs during the study period. 71% (n = 3115 residents) had data available for analysis. 56.3% of DR and 49.3% of IR residents matched in the same geographic region as their medical school. The geographic distribution of applicants who matched at Southern IR residency programs significantly changed after implementation of virtual interviews (p < 0.0001). Virtual interviews did not increase the odds of matching in the same region as one's medical school for IR (OR 1.11, p = 0.08) or DR (OR 1.01, p = 0.58) applicants. Top-20 ranked DR programs had lower odds of in-region matches (OR 0.87, p < 0.001). CONCLUSION/CONCLUSIONS:With few exceptions, shifting to virtual residency interviews did not significantly affect the geographic distribution of IR or DR residency matches. Top-ranked DR programs match more regionally diverse applicants.

PURPOSE/OBJECTIVE:To characterize the safety, efficacy, and potential role of genicular artery embolization (GAE) as a disease-modifying treatment for symptomatic knee osteoarthritis (OA). MATERIALS AND METHODS/METHODS:This is an interim analysis of a prospective, single-arm clinical trial of patients with symptomatic knee OA who failed conservative therapy for greater than 3 months. Sixteen patients who underwent GAE using 250-μm microspheres and had at least 1 month of follow-up were included. Six patients completed the 12-month follow-up, and 10 patients remain enrolled. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was evaluated at baseline and at 1, 3, and 12 months. Serum and plasma samples were collected for biomarker analysis. The primary end point was the percentage of patients who achieved the minimal clinically important difference (MCID) for WOMAC pain score at 12 months. Baseline and follow-up outcomes were analyzed using the Wilcoxon matched-pairs signed-rank test. RESULTS:Technical success of the procedure was 100%, with no major adverse events. The MCID was achieved in 5 of the 6 (83%) patients at 12 months. The mean WOMAC pain score decreased from 8.6 ± 2.7 at baseline to 4.9 ± 2.7 (P = .001), 4.4 ± 2.8 (P < .001), and 4.7 ± 2.7 (P = .094) at 1, 3, and 12 months, respectively. There was a statistically significant decrease in nerve growth factor (NGF) levels at 12 months. The remaining 8 biomarkers showed no significant change at 12 months. CONCLUSIONS:GAE is a safe and efficacious treatment for symptomatic knee OA. Decreased NGF levels after GAE may contribute to pain reduction and slowing of cartilage degeneration.

Objective: Genicular artery embolization (GAE) is a novel, minimally invasive procedure for treatment of knee osteoarthritis (OA). This meta-analysis investigated the safety and effectiveness of this procedure. Design: Outcomes of this systematic review with meta-analysis were technical success, knee pain visual analog scale (VAS; 0"“100 scale), WOMAC Total Score (0"“100 scale), retreatment rate, and adverse events. Continuous outcomes were calculated as the weighted mean difference (WMD) versus baseline. Minimal clinically important difference (MCID) and substantial clinical benefit (SCB) rates were estimated in Monte Carlo simulations. Rates of total knee replacement and repeat GAE were calculated using life-table methods. Results: In 10 groups (9 studies; 270 patients; 339 knees), GAE technical success was 99.7%. Over 12 months, the WMD ranged from −34 to −39 at each follow-up for VAS score and −28 to −34 for WOMAC Total score (all p "‹< "‹0.001). At 12 months, 78% met the MCID for VAS score; 92% met the MCID for WOMAC Total score, and 78% met the SCB for WOMAC Total score. Higher baseline knee pain severity was associated with greater improvements in knee pain. Over 2 years, 5.2% of patients underwent total knee replacement and 8.3% received repeat GAE. Adverse events were minor, with transient skin discoloration as the most common (11.6%). Conclusions: Limited evidence suggests that GAE is a safe procedure that confers improvement in knee OA symptoms at established MCID thresholds. Patients with greater knee pain severity may be more responsive to GAE.

PURPOSE/OBJECTIVE:Non-operative management of hepatic trauma with adjunctive hepatic arterial embolization (HAE) is widely accepted. Despite careful patient selection utilizing CTA, a substantial proportion of angiograms are negative for arterial injury and no HAE is performed. This study aims to determine which CT imaging findings and clinical factors are associated with the presence of active extravasation on subsequent angiography in patients with hepatic trauma. MATERIALS AND METHODS/METHODS:The charts of 243 adults who presented with abdominal trauma and underwent abdominal CTA followed by conventional angiography were retrospectively reviewed. Of these patients, 49 had hepatic injuries on CTA. Hepatic injuries were graded using the American association for the surgery of trauma (AAST) CT classification, and CT images were assessed for active contrast extravasation, arterial pseudoaneurysm, sentinel clot, hemoperitoneum, laceration in-volving more than 2 segments, and laceration involving specific anatomic landmarks (porta hepatis, hepatic veins, and gallbladder fossa). Medical records were reviewed for pre- and post-angiography blood pressures, hemoglobin levels, and transfusion requirements. Angiographic images and reports were reviewed for hepatic arterial injury and performance of HAE. RESULTS:In multivariate analysis, AAST hepatic injury grade was significantly associated with increased odds of HAE (Odds ratio: 2.5, 95% CI 1.1, 7.1, p = 0.049). Univariate analyses demonstrated no significant association between CT liver injury grade, CT characteristics of liver injury, or pre-angiographic clinical data with need for HAE. CONCLUSION/CONCLUSIONS:In patients with hepatic trauma, prediction of need for HAE based on CT findings alone is challenging; such patients require consideration of both clinical factors and imaging findings.

PURPOSE/OBJECTIVE:To evaluate ablation zone sizes in patients undergoing pulmonary tumor cryoablation with 14-gauge cryoablation probes. MATERIALS AND METHODS/METHODS:Single-center retrospective analysis of all consecutive patients who underwent cryoablation of pulmonary tumors with one or more 14-gauge probes (August 2017-June 2020) was performed. Intraprocedural and 1-2 month post-procedural chest CTs were evaluated to characterize pulmonary lesions, ice balls, and ablation zones. Single-probe 14-gauge ablation zone volumes were compared to manufacturer reference isotherms, and to single- and two-probe ablation zones from a prior investigation of 17-gauge probes. Overall and local recurrence-free survival were calculated to 3 years. RESULTS:) (all p<0.001). Three-year overall and local recurrence-free survival were 69% (95% CI: 53-89%) and 87% (95% CI: 74-100%), respectively. CONCLUSIONS:14-gauge probes generate larger ablation volumes than 17-gauge probes. Manufacturer-reported isotherms are significantly larger than actual cryoablation zones. Cryoablation can attain low rates of local recurrence.

Venous malformations, the most common type of vascular malformation, are slow-flow lesions resulting from disorganized angiogenesis. The International Society for the Study of Vascular Anomalies (ISSVA) classification offers a categorization scheme for venous malformations based on their genetic landscapes and association with congenital overgrowth syndromes. Venous malformations present as congenital lesions and can have broad physiologic and psychosocial sequelae depending on their size, location, growth trajectory, and tissue involvement. Diagnostic evaluation is centered around clinical examination, imaging evaluation with ultrasound and time-resolved magnetic resonance imaging, and genetic testing for more complex malformations. Interventional radiology has emerged as first-line management of venous malformations through endovascular treatment with embolization, while surgery and targeted molecular therapies offer additional therapeutic options. In this review, an updated overview of the genetics and clinical presentation of venous malformations in conjunction with key aspects of diagnostic imaging and treatment are discussed.

Purpose: To determine the safety and effectiveness of genicular artery embolization (GAE) in reducing knee pain in patients with mild to moderate knee osteoarthritis (OA), as measured by validated patient reported outcome measures, and to characterize pre/post-procedural trends in multiple OA-associated serum biomarkers
Material(s) and Method(s): In an ongoing, prospective, single-arm clinical trial, patients with mild to moderate (Kellgren-Lawrence grade 2-3) symptomatic knee OA, without prior surgery and who failed conservative therapy, were included. Pre-intervention imaging (plain radiographs and MRI), patient-reported outcome measures (KOOS, WOMAC, VAS), and serum biomarkers (IL-1Ra, CRP, Hyaluronan, COMP, VEGF, CCL2-MCP-1) were obtained. Each patient underwent transcatheter arterial embolization of one or more genicular arteries in the affected knee using 250-mum microspheres (Embozene, Varian). One- and three-month post-intervention patient-reported outcome measures and serum biomarkers were obtained. Baseline and follow-up outcomes were compared using paired Wilcoxon signed-rank tests.
Result(s): The first 7 patients (4 male, mean age 68 +/- 6y, mean BMI 30 +/- 2) recruited into this trial were included in this preliminary analysis. Technical success was 100%. There were no adverse events. By 3 months, VAS pain scores decreased from 56 to 21 (63% decrease); WOMAC pain scores decreased from 8 to 4 (50% decrease); and KOOS pain scores (for which higher scores indicate less pain) increased from 57 to 81 (42% increase), all P >0.05. Baseline and 3-month mean biomarker values were: IL-1Ra (471 +/- 276 vs 590 +/- 320 pg/mL), CRP (1.81 +/- 1.78 vs 3.24 +/- 4.25 mg/L), Hyaluronan (92 +/- 66 vs 166 +/- 102 ng/mL), COMP (942 +/- 336 vs 1057 +/- 462 ng/mL), VEGF (372 +/- 283 vs 303 +/- 101 pg/mL), and CCL2-MCP-1 (335 +/- 90 vs 323 +/- 69 pg/mL), all P >0.05.
Conclusion(s): Patient-reported pain scores demonstrated a trend in improvement 3 months after GAE at our interim analysis. There were no significant changes between baseline and 3-month follow-up in serum OA biomarkers in this small sample size. Full study analysis will further delineate trends in serum biomarkers after GAE.
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Purpose: To evaluate the cryoablation zones generated in human subjects during the treatment of pulmonary tumors using 14-gauge cryoablation probes; current understanding of in vivo pulmonary cryoablation zone volumes stems predominantly from study of 17-gauge probes
Material(s) and Method(s): A single-center database of all adult patients who underwent CT-guided cryoablation of pulmonary tumors between August 2017 and June 2020 was compiled. All patients were treated using one or more 14-gauge cryoablation probes. Intraprocedural and 1- to 2-month post-procedural chest CTs were evaluated to characterize pulmonary lesions, procedural ice balls, and follow-up ablation zones. Comparison of single-probe ablation zone volumes to manufacturer reference values, and to previously published data on 17-gauge probes was performed using the Wilcoxon rank-sum test. Comparison of ablation zone volume to the number of probes used, distance of the pulmonary lesion to the pleura, and distance of the pulmonary lesion to the nearest >=3 mm vessel, were performed using Kruskal-Wallis and Pearson correlation tests.
Result(s): Pulmonary cryoablation was performed on 47 pulmonary lesions (64% primary adenocarcinoma) across 45 unique procedures on 42 patients (Female: 50%; Mean age: 75.2 +/- 11.5 years). Mean intraprocedural ice ball volume when 1, 2, or 3 probes were used was 5.4 +/- 3.8, 8.0 +/- 4.8, and 22.9 +/- 10.8 cm³, respectively. Mean cryoablation zone volume at 1-2 months when 1, 2, or 3 probes were used was 5.0 +/- 2.3, 37.5 +/- 20.5, and 28.4 cm³, respectively (n = 1 for 3 probes). Mean single-probe ablation zone volume (5.0 +/- 2.3 cm³) was significantly larger than that previously reported for 17-gauge probes (3.0 +/- 0.3 cm³) (P = 0.014)¹, but significantly smaller than manufacturer-reported in vitro 0degreeC, -20degreeC, and -40degreeC isotherms (all P < 0.0001). The number of probes was significantly associated with ablation zone volume (P = 0.0033). Mean cryoablation zone volume was not significantly associated with lesion distance to pleura (P=0.40) or lesion distance to the nearest >=3 mm vessel (P = 0.60).
Conclusion(s): Single-probe pulmonary cryoablation with 14-gauge probes generates significantly larger ablation zone volumes than with 17-gauge probes. In vivo pulmonary cryoablation generates significantly smaller ablation zone volumes than manufacturer-reported in vitro isotherms. Use of multiple probes significantly increased ablation zone volume compared with use of a single probe.
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