Contralateral Hypertrophy Post Yttrium-90 Transarterial Radioembolization in Patients With Hepatocellular Carcinoma and Portal Vein Tumor Thrombus.

Objectives Contralateral hypertrophy of non-irradiated liver following Yttrium-90 (90Y) transarterial radioembolization (TARE) is increasingly recognized as an option to facilitate curative surgical resection in patients that would otherwise not be surgical candidates due to a small future liver remnant (FLR). This study aimed to investigate the correlation between patient features and liver hypertrophy and identify potential predictors for liver growth in patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT) undergoing TARE. Methodology Twenty-three patients with HCC and PVTT were included. Contralateral liver hypertrophy was assessed at six months posttreatment based on CT or MRI imaging. Thirteen patient features were selected for statistical and prediction analysis. Univariate Spearman correlation and analysis of variance (ANOVA) tests were performed. Subsequently, four feature-selection methods based on multivariate analysis were used to improve model generalization performance. The selected features were applied to train linear regression models, with fivefold cross-validation to assess the performance of the predicted models. Results The ratio of disease-free target liver volume to spared liver volume and total liver volume showed the highest correlations with contralateral hypertrophy (P-values = 0.03 and 0.05, respectively). In three out of four feature-selection methods, the feature of disease-free target liver volume to total liver volume ratio was selected, having positive correlations with the outcome and suggesting that more hypertrophy may be expected when more volume of disease-free liver is irradiated. Conclusions Contralateral hypertrophy post-90Y TARE can be an option for facilitating surgical resection in patients with otherwise small FLR.

The Aortic Team Model and Collaborative Decision Pathways for the Management of Complex Aortic Disease: Clinical Practice Update From the Canadian Cardiovascular Society/Canadian Society of Cardiac Surgeons/Canadian Society for Vascular Surgery/Canadian Association for Interventional Radiology.

Disease of the aortic arch, descending thoracic, or thoracoabdominal aorta necessitates dedicated expertise across medical, endovascular, and surgical specialties. Cardiologists, cardiac surgeons, vascular surgeons, interventional radiologists, and others have expertise and skills that aid in the management of patients with complex aortic disease. No specialty is uniformly expert in all aspects of required care. Because of this dispersion of expertise across specialties, an aortic team model approach to decision-making and treatment is advocated. A nonhierarchical partnership across specialties within an interdisciplinary aortic clinic ensures that all treatment options are considered and promotes shared decision-making between the patient and all aortic experts. Furthermore, regionalization of care for aortic disease of increased complexity assures that the breadth of treatment options is available and that favourable volume-outcome ratios for high-risk procedures are maintained. An awareness of best practice care pathways for patient referrals for preventative management, acute care scenarios, chronic care scenarios, and pregnancy might facilitate a more organized management schema for aortic disease across Canada and improve lifelong surveillance initiatives.

Prospective evaluation of efficacy and safety of distal radial and radial artery access using a novel articulating-tip guidewire.

BACKGROUND: Guidewire-facilitated access to peripheral vessels is commonplace in vascular access, but guidewire insertion into small vessels, such as the radial and distal radial arteries, can still be challenging. Failure to gain access on the first attempt may contribute to increased risks of procedural complications, such as vessel dissection, spasm, and occlusion. This research assessed the safety and efficacy of radial and distal radial artery access using a novel, FDA-cleared, small-core-diameter guidewire with an articulating tip, under ultrasound guidance. METHODS: This was a prospective, single-arm, single-center trial. Patients in need of vascular access were screened for participation and enrolled in the study. Guidewire insertion was attempted by four physicians (three interventional radiologists and an interventional nephrologist) at 162 arterial sites-65 radial and 97 distal radial, having a mean diameter of 2.0 mm. RESULTS: First-attempt successful placement of the guidewire in the artery occurred at 87.6% of access sites (142/162) and differences in the success rate between the radial and distal radial arteries or between vessels with diameter smaller or larger than 2 mm were not observed (62/68 and 67/77, respectively; p = 0.6). Four of the five reported adverse events were unrelated to the study device or procedure. Two of the three distal radial artery spasms occurred before the guidewire was used. The other two events were a radial artery spasm, and a distal radial artery site hematoma. All adverse events resolved spontaneously. CONCLUSIONS: First-attempt placement of a novel articulating tip guidewire in the radial and distal radial arteries occurred at a high rate in our study and was not associated with safety concerns.

Hepatic Hilar Nerve Block for Adjunctive Analgesia during Percutaneous Thermal Ablation of Hepatic Tumors: A Retrospective Analysis.

PURPOSE: To determine whether hepatic hilar nerve block techniques reduce analgesic and sedation requirements during percutaneous image-guided thermal ablation of hepatic tumors. MATERIALS AND METHODS: A single-center retrospective cohort analysis was performed of 177 patients (median age, 67 years; range, 33-86 years) who underwent percutaneous image-guided thermal ablation of liver tumors. All patients were treated utilizing local anesthetic and moderate sedation between November 2018 and November 2021 at a tertiary level hospital, with or without the administration of a hepatic hilar nerve block. Univariable and multivariable linear regression analyses were performed to determine the relationship between the administration of the hilar nerve block and fentanyl and midazolam dosages. RESULTS: A total of 114 (64%) patients received a hilar nerve block in addition to procedural sedation, and 63 (36%) patients received procedural sedation alone. There were no significant differences in the baseline demographic and tumor characteristics between the cohorts. The procedure duration was longer in the hilar block cohort than in the unblocked cohort (median, 95 vs 82 minutes; P = .0012). The technical success rate (98% in both the cohorts, P = .93) and adverse event rate (11% vs 3%, P = .14) were not significantly different between the cohorts. After adjusting for patient and tumor characteristics, ablation modality, and procedure and ablation durations, hilar nerve blocks were associated with lower fentanyl (-18.4%, P = .0045) and midazolam (-22.7%, P = .0007) dosages. CONCLUSIONS: Hepatic hilar nerve blocks significantly decrease the fentanyl and midazolam requirements during thermal ablation of hepatic tumors, without a significant change in the technical success or adverse event rates.

Distal Transradial Artery Access for Neuroangiography and Neurointerventions : Pitfalls and Exploring the Boundaries.

INTRODUCTION: The distal transradial approach (dTRA) is progressively gaining more clinical use in the fields of cardiology and other vascular interventions, as it offers a number of advantages compared to conventional radial approach (TRA). These include lower rates of vascular occlusion which permits preservation of the proximal radial artery for future procedures in the event of a distal occlusion. AIM: To share the experience in the use of dTRA for neurointerventions, showing its advantages, pitfalls as well as sharing our optimized puncture and hemostatic ultrarapid compression protocols to improve the use of this vascular access. METHODS: A retrospective analysis of our experience of diagnostic and interventional procedures performed via dTRA using an optimized protocol for puncture and postpuncture compression of the dTRA was performed. The rate of complications (hematoma and arterial dissection at puncture site) femoral crossover, and assessment of postprocedural stenosis/occlusion with the ultrarapid compression protocol were also assessed. RESULTS: From March 2019 to July 2020 a total of 100 distal radial procedures were carried out and 53 diagnostic angiograms (53%) and 47 interventional procedures (47%) were included in the analysis. We achieved a 96% technical success, with a femoral crossover requirement in 3 cases (3%), and one conventional TRA crossover due to puncture failure. Of the patients 3 presented puncture site hematomas (3%) with no intervention required, 61 patients (61%) underwent the ultrarapid hemostasis protocol in association with a hemostatic pad. Ultrasound follow-up was performed in 20 patients (20%) at 1-2 months with 1 case of occlusion (5%) and 2 of radial stenosis (10%). In all 3 cases proximal radial artery remained patent. CONCLUSION: The dTRA is a safe and feasible access route for angiography and neurointerventions. Using vasodilators prepuncture, we attained a variable increase in the vascular diameter facilitating puncture and reducing the risk of occlusion and vascular spasm. A rapid deflation protocol for postpuncture hemostasis does not significantly increase the hematoma rate.

Non-target digital ischemia in an ulnar artery distribution following transradial access: Case report and review of best practice techniques.

Transradial access is a safe approach for visceral endovascular interventions, with lower complication rates compared to transfemoral access. This report describes an unusual case of ulnar artery thrombosis following splenic artery aneurysm embolization via left transradial approach, resulting in non-target digital ischemia and eventual amputation of the ring and little finger distal phalanges. Technical considerations to reduce the incidence of access complications are also reviewed, along with practice modifications undertaken at our institution following this case to improve outcomes.

The Many Care Models to Treat Thoracic Aortic Disease in Canada: A Nationwide Survey of Cardiac Surgeons, Cardiologists, Interventional Radiologists, and Vascular Surgeons.

BACKGROUND: Several specialties treat thoracic aortic disease, resulting in multiple patient care pathways. This study aimed to characterize these varied care models to guide health policy. METHODS: A 57-question e-survey was sent to staff cardiac surgeons, cardiologists, interventional radiologists, and vascular surgeons at 7 Canadian medical societies. RESULTS: For 914 physicians, the response rate was 76% (86 of 113) for cardiac surgeons, 40% (58 of 146) for vascular surgeons, 24% (34 of 140) for radiologists, and 14% (70 of 515) for cardiologists. Several services admitted type B dissections (vascular 37%, cardiology 31%, cardiac 18%, other 7%), and care was heterogeneous. Ownership of disease management was overestimated relative to the perspective of the other specialties. Type A dissection admissions and treatment were more uniform, but emergent call coverage varied. A 24/7 aortic specialist on-call schedule was present only 4% of the time. "Aortic" case rounds promoted attendance by a broader aortic specialty contingency relative to rounds that were specialty specific. Although 89% of respondents felt an aortic team was best for patient care, only 54% worked at an institution with an aortic team present, and only 28% utilized an aortic clinic. Questions designed to define an aortic team derived 63 different combinations. CONCLUSIONS: Thoracic aortic disease follows a network of undefined and variable care pathways, despite its high-risk population in need of complex treatment considerations. Multidisciplinary aortic teams and clinics exist in low volume, and the "aortic team" remains an obscure construct. A multispecialty initiative to define the aortic team and outline standardized navigation pathways within the health systems hospitals is advocated.

CONTEXTE: La prise en charge de la maladie de l'aorte thoracique peut faire appel à plusieurs spécialités, ce qui a pour effet de multiplier les trajectoires de soins des patients. Cette étude visait à caractériser ces différents modèles de soins afin d'éclairer l'élaboration des politiques de santé. MÉTHODOLOGIE: Un sondage électronique de 57 questions a été envoyé aux chirurgiens cardiaques, aux cardiologues, aux radiologistes interventionnels et aux chirurgiens vasculaires membres de 7 associations médicales canadiennes. RÉSULTATS: Sur un total de 914 médecins, le taux de réponse a été de 76 % (86 sur 113) chez les chirurgiens cardiaques, de 40 % (58 sur 146) chez les chirurgiens vasculaires, de 24 % (34 sur 140) chez les radiologistes et de 14 % (70 sur 515) chez les cardiologues. Plusieurs services avaient admis des cas de dissection aortique de type B (chirurgie vasculaire 37 %, cardiologie 31 %, chirurgie cardiaque 18 %, autre 7 %) et les soins étaient hétérogènes. Les spécialistes surestimaient leur responsabilité de la prise en charge des cas par rapport à celle des autres spécialistes. Les admissions de cas de dissection de type A et leur traitement étaient plus uniformes, mais la présence de spécialistes de garde pouvant traiter les cas urgents était variable. La présence continue d'un spécialiste de l'aorte de garde n'était observée que pendant 4 % du temps. Les séances de discussion de cas « aortiques ¼ favorisaient la participation par une gamme plus large de spécialistes de l'aorte que les discussions axées sur une spécialité donnée. Si 89 % des répondants estimaient qu'une équipe « aortique ¼ était la meilleure option pour les soins aux patients, ils n'étaient que 54 % à travailler dans un établissement disposant d'une telle équipe et 28 % à utiliser les services d'une clinique de l'aorte. En réponse aux questions portant sur les éléments constitutifs d'une équipe aortique, 63 combinaisons différentes de spécialités ont été proposées. CONCLUSIONS: La prise en charge de la maladie de l'aorte thoracique emprunte un dédale de trajectoires de soins non définies et variables, alors que sa population à haut risque a besoin de traitements complexes. Les équipes multidisciplinaires et les cliniques spécialisées dans le traitement de l'aorte sont rares, et la notion d' « équipe aortique ¼ demeure un concept obscur. Nous préconisons une initiative réunissant des spécialistes de différents domaines pour définir les éléments constitutifs d'une équipe aortique et établir des trajectoires de navigation normalisées au sein des hôpitaux du système de santé.

Ultrasound-guided access to the distal radial artery at the anatomical snuffbox for catheter-based vascular interventions: a technical guide.

Conventional radial access has been shown to have many advantages over the transfemoral approach. The risk of potential radial artery occlusion and subsequent hand ischaemia can be reduced further by accessing the vessel distally at the anatomical snuffbox, allowing maintenance of antegrade flow to the hand by the superficial palmar arch branch. Additional potential advantages of distal radial access in comparison to the conventional radial approach at the wrist include fewer puncture-site complications and faster post-procedural haemostasis as the vessel is very superficial. Furthermore, it provides another safe, non-femoral option for vascular access. The use of ultrasound guidance enables the operator to identify important anatomical landmarks and avoid injuring adjacent structures. We provide a detailed step-by-step guide for performing distal radial access using sonographic and anatomical correlation, thereby facilitating safe access and optimising technical success.

Safety and Efficacy of a Truncated Deflation Algorithm for Distal Transradial Access.

PURPOSE: To assess safety and efficacy of a modified rapid hemostasis protocol for distal transradial access (TRA). MATERIALS AND METHODS: A single-center retrospective study of patients undergoing percutaneous image-guided procedures from a distal TRA with rapid deflation hemostasis protocol was performed. Between March 2017 and August 2019, 593 procedures in 434 patients were performed. Mean patient age was 63.5 y (range, 18-94 y). RESULTS: The most common procedures were transarterial chemoembolization (218; 36.8%), abdominal and pelvic embolization (116; 19.6%), yttrium-90 mapping (115; 19.4%), yttrium-90 administration (84; 14.2%), and diagnostic angiography (44; 7.4%). Mean (range) values for clotting parameters were international normalized ratio 1.2 (0.9-3.2), partial thromboplastin time 33.5 s (26-44 s), and platelets 23.4 × 109/L (37-552 × 109/L). A hematoma developed in 7 (1.2%) patients. No radial artery occlusions were encountered during follow-up. Nursing intensity was defined as the number of minutes after the procedure required for assessing and managing the access site for bleeding. The mean nursing intensity was 25.1 min (range, 25-40 min). CONCLUSIONS: The rapid deflation hemostasis protocol for distal TRA at the anatomical snuffbox was feasible and safe. No significant difference or association was found between hematoma formation and clotting parameters after the procedure or type of vascular access equipment used.

Left Distal Transradial Access (ldTRA): A Comparative Assessment of Conventional and Distal Radial Artery Size.

PURPOSE: To assess left radial artery size, technical feasibility and safety of ldTRA in the anatomical snuffbox for percutaneous image-guided procedures. MATERIALS AND METHODS: A retrospective single-center study was performed from November 2016 to June 2018 on all patients undergoing ldTRA for interventional radiology procedures. RESULTS: A total of 287 patients (91 female and 196 male), aged 18-94 years (mean age 64 years), were included. 389 procedures were performed which included hepatic chemoembolization (n = 161), selective internal radiation therapy Y-90 mapping (n = 74), selective internal radiation therapy Y-90 administration (n = 48), diagnostic angiography (n = 34), mesenteric and pelvic embolization (n = 59), stent insertion (n = 8) and miscellaneous (n = 5). Mean sonographic measurement of the left radial artery size at the conventional site at the wrist was 2.55 mm (range 1.4-3.3 mm) and 2.34 mm (range 1.4-3.2 mm) at the anatomical snuffbox (p < 0.001). Technical success rate was 100%, a single small hematoma occurred in the first patient (0.3%). 74.2% of patients had follow-up for radial artery patency (mean 46 days, range 0-66 days), which did not reveal radial artery occlusions or pseudoaneurysm formation. CONCLUSION: The left distal radial artery in the anatomical snuffbox is smaller in comparison with the conventional access site at the wrist. The difference however is small and does not require intentional downsizing of vascular access equipment to facilitate utilization of ldTRA. Assessment of the vessel size is imperative for appropriate equipment selection and optimizing procedural success. This study supports that ldTRA is technically feasible and safe.

Interventional radiology and COVID-19: evidence-based measures to limit transmission.

As we face an explosion of COVID-19 cases and deal with an unprecedented set of circumstances all over the world, healthcare personnel are at the forefront, dealing with this emerging scenario. Certain subspecialties like interventional radiology entails a greater risk of acquiring and transmitting infection due to the close patient contact and invasive patient care the service provides. This makes it imperative to develop and set guidelines in place to limit transmission and utilize resources in an optimal fashion. A multi-tiered approach needs to be devised and monitored at the administrative level, taking into account the various staff and patient contact points. Based on these factors, work site and health force rearrangements need to be in place while enforcing segregation and disinfection parameters. We are putting forth an all-encompassing review of infection control measures that cover the dynamics of patient care and staff protocols that such a situation demands of an interventional department.

Ablative Transarterial Radioembolization Improves Survival in Patients with HCC and Portal Vein Tumor Thrombus.

PURPOSE: Patients with hepatocellular carcinoma and portal vein tumor thrombus have a poor prognosis and limited therapeutic options. We sought to compare survival, tolerability, and safety in such patients treated with conventional yttrium-90 transarterial radioembolization dosimetric techniques or ablative transarterial radioembolization. MATERIALS AND METHODS: This retrospective, single-center cohort study included patients with hepatocellular carcinoma and right, left, and/or main portal vein tumor thrombus, preserved liver function (Child-Pugh class ≤ B7), and good performance status (Eastern Cooperative Oncology Group score ≤ 1) treated with yttrium-90 microspheres from 2011 to 2018 with ablative intent transarterial radioembolization (A-TARE), or conventional technique (cTARE). Statistical models were used to compare overall survival, post-treatment survival, toxicities, and prognosticators of response. RESULTS: Fifty-seven patients were included (21 [36.8%] ablative and 36 [63.2%] conventional intent). Median overall survival was 15.7 months. Compared to conventional treatment, ablative radioembolization was associated with longer median overall survival (45.3 vs 18.2 months; P = 0.003), longer post-treatment survival (19.1 vs 4.9 months; P = 0.005), a 70% lower risk of death (hazard ratio 0.30; 95% confidence interval, 0.13-0.70; P = 0.005), and improved 4-year survival (53.9% vs 11.2%). Overall survival did not differ significantly between treatment with resin and glass microspheres (27.5 vs 22.2 months; P = 0.62). Acceptable hepatic toxicities were observed after yttrium-90 administration, without statistical differences between the groups. CONCLUSION: In patients with advanced hepatocellular carcinoma and portal vein tumor thrombus, A-TARE is associated with longer survival than cTARE. Neither modality is associated with deleterious effects on liver function.

Transapical Coil Embolization of a Postsurgical Ascending Thoracic Aortic Pseudoaneurysm.

Ascending aortic pseudoaneurysms are a rare but potentially life-threatening complication of aortic root or cardiac surgery. Surgical repair is established as first-line treatment; however, patient comorbidities, technical considerations, and anatomic limitations often preclude patients from repeat surgery, thus necessitating alternative approaches. Here, we present a case of coil embolization of an ascending aortic pseudoaneurysm via a transapical approach in a particularly complex scenario where percutaneous and peripheral access was technically unfeasible.

Radical Radial: Pearls and Pitfalls in Transradial Yttrium-90 Liver-Directed Therapy.

The frequency of transradial access in interventional radiology has been steadily increasing, including for yttrium-90 (Y-90) selective internal radiation therapy to treat hepatic malignancies. The aim of this article is to detail an optimized approach to transradial Y-90 (TRY-90), showing it to be a safe and feasible first-line approach to hepatic selective internal radiation therapy. Salient preprocedural considerations to enable appropriate patient selection for TRY-90 are discussed and a detailed equipment list is provided. The article will describe our approach to TRY-90 in addition to a discussion around technical pearls and pitfalls.

Retrievable Inferior Vena Cava Filters: A Tertiary Centre Perspective and Quality Assurance Study.

PURPOSE: To conduct a retrospective review and quality assurance study of inferior vena cava (IVC) filter retrieval over a two-year period at a tertiary care centre. METHODS: Patients who underwent IVC filter placement or retrieval over a two-year period were identified. Medical records were reviewed for patient characteristics, filter indication, time to filter retrieval, and complications. RESULTS: IVC filters were placed in 229 patients between January 1, 2015 and December 31, 2016. 113 retrievals were attempted and 101 filters were successfully retrieved (89.4%). Median time to first retrieval attempt was 48 days (range of 5-728). Seventy-one patients died in the interval after filter insertion before a retrieval attempt at a median time of 27 days (range of 3-430). In 17 patients, retrieval was complicated by or delayed because of penetration of IVC wall (n = 6), large thrombus burden trapped by filter (n = 5), filter tilt or migration (n = 3), and unclear reasons (n = 3). Time-to-first unsuccessful retrieval attempt was 141 days (median). Of all filters placed, 55.9% were never retrieved. Excluding deceased patients with in-situ filters (n = 71) and unsuccessful retrievals left in-situ as permanent filters (n = 5), there remains 52 patients (33%), with a median filter in-situ time of 488 days. CONCLUSION: Our study indicates that as many as 33% of patients may have been lost to follow-up of their in-situ IVC filter. Considering widespread reports of long-term complications and the recent safety alert issued by Health Canada, it is evident that a unified strategy is needed to track patients post filter insertion.

Prospective Study on Total Fluoroscopic Time in Patients Undergoing Uterine Artery Embolization: Comparing Transradial and Transfemoral Approaches.

PURPOSE: Comparing total fluoroscopy time (FT) to perform uterine artery embolization (UAE) with transradial approach (TRA) versus transfemoral approach (TFA). Our hypothesis was that there would be no significant procedural time penalty incurred, despite the learning curve associated with adopting a new approach. MATERIALS AND METHODS: A cohort study was undertaken including 66 consecutive patients undergoing UAE with either TRA/TFA between January and September 2015. Total FT was recorded prospectively for each procedure, and data subsequently analyzed retrospectively. Each operator had at least 2 years of experience as an interventional radiologist having performed at least 200 TFA UAEs. All operators had recently incorporated TRA into their practice. RESULTS: A total of 39 TFA and 27 TRA cases were included in the study; mean age for TFA group was 44.4 years (± 4.9) and for TRA group was 45.1 years (± 4.9) (p = 0.59). Mean FTs were comparable between the two groups (p = 0.86) despite a learning curve associated with TRA: The mean total FT with TFA was 20.36 min (± 9.48) compared to TRA 20.12 min (± 7.67). CONCLUSIONS: FTs for TRA UAE were comparable to TFA UAE, even though TRA had been recently adopted as a new approach. Despite the learning curve associated with developing a novel technique, operators should not expect the efficiency of their service to be significantly compromised. Introducing this safe and effective method of vascular access should therefore be considered.

Safety and efficacy of venoplasty in MS: A randomized, double-blind, sham-controlled phase II trial.

OBJECTIVE: To determine the safety and efficacy of balloon vs sham venoplasty of narrowing of the extracranial jugular and azygos veins in multiple sclerosis (MS). METHODS: Patients with relapsing or progressive MS were screened using clinical and ultrasound criteria. After confirmation of >50% narrowing by venography, participants were randomized 1:1 to receive balloon or sham venoplasty of all stenoses and were followed for 48 weeks. Participants and research staff were blinded to intervention allocation. The primary safety outcome was the number of adverse events (AEs) during 48 weeks. The primary efficacy outcome was the change from baseline to week 48 in the patient-reported outcome MS Quality of Life-54 (MSQOL-54) questionnaire. Standardized clinical and MRI outcomes were also evaluated. RESULTS: One hundred four participants were randomized (55 sham; 49 venoplasty) and 103 completed 48 weeks of follow-up. Twenty-three sham and 21 venoplasty participants reported at least 1 AE; one sham (2%) and 5 (10%) venoplasty participants had a serious AE. The mean improvement in MSQOL-54 physical score was +1.3 (sham) and +1.4 (venoplasty) (p = 0.95); MSQOL-54 mental score was +1.2 (sham) and -0.8 (venoplasty) (p = 0.55). CONCLUSIONS: Our data do not support the continued use of venoplasty of extracranial jugular and/or azygous venous narrowing to improve patient-reported outcomes, chronic MS symptoms, or the disease course of MS. CLINICALTRIALSGOV IDENTIFIER: NCT01864941. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that for patients with MS, balloon venoplasty of extracranial jugular and azygous veins is not beneficial in improving patient-reported, standardized clinical, or MRI outcomes.

Interventional Radiology in Canada: Current Challenges and Future Directions.

OBJECTIVE: We aim to define the practice of interventional radiology (IR) in Canada, barriers that have been faced by interventional radiologists, and ways in which the Canadian Interventional Radiology Association (CIRA) have attempted to address these issues. CONCLUSION: IR has faced significant challenges in the Canadian setting. Recognizing the need to address these challenges, leaders in the field of IR in Canada founded the CIRA to serve as our national voice and lobby group.

Intraprocedural Parenchymal Blood Volume Is a Predictor of Treatment Response for Chemoembolization in Hepatocellular Carcinoma: Results of a Prospective Study.

PURPOSE: To evaluate cone-beam parenchymal blood volume (PBV) before and after embolization as a predictor of radiographic response to transarterial chemoembolization in unresectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A phase IIa prospective clinical trial was conducted in patients with HCCs > 1.5 cm undergoing chemoembolization; 52 tumors in 40 patients with Barcelona Clinic Liver Criteria stage B disease met inclusion criteria. Pre- and postembolization PBV analysis was performed with a semiquantitative best-fit methodology for index tumors, with a predefined primary endpoint of radiographic response at 3 months. Analyses were conducted with Wilcoxon signed-rank tests and one-way analysis of variance on ranks. RESULTS: Mean tumoral PBV measurements before and after embolization were 170 mL/1,000 mL ± 120 and 0 mL/100 mL ± 130, respectively. Per modified Response Evaluation Criteria In Solid Tumors, 25 tumors (48%) exhibited complete response (CR), 13 (25%) partial response (PR), 3 (6%) stable disease (SD), and 11 (21%) progressive disease (PD). Statistically significant changes in median PBV (ΔPBV) were identified in the CR (P = .001) and PR (P = .003) groups, with no significant difference observed in SD (P = .30) and PD groups (P = .06). A statistically significant correlation between ΔPBV and tumor response was established by one-way analysis of variance on ranks (P = .036; CR, 200 mL/100 mL ± 99; PR, 240 mL/100 mL ± 370; SD, 64 mL/100 mL ± 99; PD, 88 mL/100 mL ± 129). CONCLUSIONS: Intraprocedural PBV can be used as a predictor of response in index HCC tumors of > 1.5 cm.