Society of Interventional Radiology Research Reporting Standards for Genicular Artery Embolization.

Genicular artery embolization (GAE) is an emerging, minimally invasive therapy to address the global burden of knee osteoarthritis (OA) and the unmet needs for medically refractory disease. Although total knee arthroplasty has been a standard intervention for severe cases, GAE is developing into a promising alternative, particularly for patients ineligible for or unwilling to undergo surgery. GAE targets the inflammatory cascade underlying OA pathophysiology by arresting neoangiogenesis and preventing pathological neoinnervation, offering potential pain relief. Although early studies have established safety and short-term effectiveness, ensuing studies are needed to validate long-term safety, durability, and comparative effectiveness and to optimize patient selection, embolic agent selection, and administration techniques. Standardized reporting guidelines are therefore essential to enhance transparency and reproducibility across clinical trials, facilitating data aggregation and comparison. This Society of Interventional Radiology (SIR)-endorsed reporting standards consensus document provides a framework to harmonize future research efforts and to improve the interpretation of outcomes.

Updates on the Model for End-Stage Liver Disease Score and Impact on the Liver Transplant Waiting List: A Narrative Review.

The model for end-stage liver disease (MELD) score is an established indicator of cirrhosis severity and a predictor of morbidity and mortality in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) creation and for allocation in liver transplantation. Since the adoption of the score, its use has been expanded to multiple new indications requiring model modifications, including relevant clinical and demographic variables, to increase predictive accuracy. The purpose of this report is to provide an update on the modifications made to the MELD score, comparing their performance with C statistics, advantages and disadvantages, and impact on mortality at 3 months after placing a TIPS or awaiting liver transplantation.

Endovascular Assessment of Liver Hemodynamics in Patients with Cirrhosis Complicated by Portal Hypertension.

The hepatic venous pressure gradient (HVPG) is currently considered the gold standard to assess portal hypertension (PH) in patients with cirrhosis. A meticulous technique is important to achieve accurate and reproducible results, and values obtained during measurement are applied in risk stratification of patients with PH, allocating treatment options, monitoring follow-up, and deciding management options in surgical patients. The use of portosystemic pressure gradients in patients undergoing placement of transjugular intrahepatic portosystemic shunts has been studied extensively and has great influence on decisions on shunt diameter. The purpose of this study was to describe the recommended technique to measure HVPG and portosystemic pressure gradient and to review the existing literature describing the importance of these hemodynamic measurements in clinical practice.

Assessing the Effects of Geniculate Artery Embolization in a Nonsurgical Animal Model of Osteoarthritis.

PURPOSE: To create a nonsurgical animal model of osteoarthritis (OA) to evaluate the effects of embolotherapy during geniculate artery embolization (GAE). MATERIALS AND METHODS: Fluoroscopy-guided injections of 700 mg of sodium monoiodoacetate were performed into the left stifle in 6 rams. Kinematic data were collected before and after induction. At 10 weeks after induction, Subjects 1 and 4-6 underwent magnetic resonance (MR) imaging with dynamic contrast enhancement (DCE) and Subjects 1, 3, and 4-6 underwent angiography with angiographic scoring to identify regions with greatest disease severity for superselective embolization (75-250-µm microspheres). Target vessel size was measured. At 24 weeks after angiography, DCE-MR imaging, angiography, and euthanasia were performed, and bilateral stifles were harvested. Medial/lateral tibial and femoral condylar, patellar, and synovial samples were cut, preserved, decalcified, and scored using the Osteoarthritis Research Society International criteria. The stifle and synovium Whole-Organ Magnetic Resonance Imaging Score and Multicenter Osteoarthritis Study score were determined. The volume transfer constant (Ktrans) and extracellular volume fraction (ve) were calculated from DCE-MR imaging along the lateral synovial regions of interest. RESULTS: The mean gross and microscopic pathological scores were elevated at 38 and 61, respectively. Mean synovitis score was elevated at 9.2. Mean pre-embolization and postembolization angiographic scores were 5 and 3.8, respectively. Mean superior, transverse, and inferior geniculate artery diameters were 3.1 mm ± 1.21, 2.0 mm ± 0.50, and 1.6 mm ± 0.41 mm, respectively. Mean pre-embolization and postembolization cartilage and synovitis scores were elevated at 35.13 and 73.3 and 5.5 and 9.2, respectively. The Ktrans/ve values of Subjects 4, 5, and 6 were elevated at 0.049/0.38, 0.074/0.53, and 0.065/0.51, respectively. Altered gait of the hind limb was observed in all subjects after induction, with reduced joint mobility. No skin necrosis or osteonecrosis was observed. CONCLUSIONS: A nonsurgical ovine animal knee OA model was created, which allowed the collection of angiographic, histopathological, MR imaging, and kinematic data to study the effects of GAE.

Improving Cone-Beam CT Angiography for Prostatic Artery Embolization: Is a Low-Dose Protocol Equivalent to the Standard?

PURPOSE: To compare the utility of low-dose versus standard cone-beam computed tomography (CT) angiography protocols in identifying nontarget embolization (NTE) during prostatic artery embolization (PAE). MATERIALS AND METHODS: A prospective, single-center, Phase-1 study (NCT02592473) was conducted for lower urinary tract symptoms in benign prostatic hyperplasia. Prostate volume, international prostate symptom score (IPSS), quality of life score (QoL), International Index of Erectile Function (IIEF), peak flow rate, UCLA Prostate Cancer Index (UCLA-PCI), and postvoid residual were recorded at baseline and 1, 3, 6, 12, and 24-months after PAE. Six-second (standard protocol, n = 29) or 5-second (low-dose protocol n = 45) rotations were made. Images were selected and matched in pairs by areas of NTE and compared by readers using a binomial generalized estimating equation model. Procedural outcomes were analyzed using a linear mixed model. RESULTS: Seventy-four cone-beam CT angiographies were performed in 21 patients. IPSS and QoL scores significantly improved (P <.05). There was no change in UCLA-PCI or IIEF scores. Dose area product of the low- and standard-dose protocol were 37,340.82 mGy·cm2 ± 104.66 and 62,645.66 mGy·cm2 ± 12,711.48, respectively, representing a dose reduction of 40.4%. A total of 120 comparisons showed no preference between the 2 protocols (P =.24). Observers identified 76 and 69 instances of NTE in the standard- and low-dose protocols, respectively (P =.125). CONCLUSIONS: Low-dose cone-beam CT angiography achieved equivalent clinical utility in identifying NTE during PAE, with the advantage of a lower radiation dose.

Improvement in Quality of Life and Decrease in Large-Volume Paracentesis Requirements With the Automated Low-Flow Ascites Pump.

The automated low-flow ascites pump (alfapump) is an implantable device that drains ascites directly into the urinary bladder. We studied its safety (absence of serious complications) and efficacy (decreased large-volume paracentesis [LVP] requirement and improved quality of life [QoL]) in the management of ascites in a cohort of North American patients with cirrhosis and recurrent ascites ineligible for transjugular intrahepatic portosystemic shunt (TIPS). QoL was measured by the Chronic Liver Disease Questionnaire (CLDQ) and Ascites Questionnaire (Ascites Q). Following alfapump implantation, patients were monitored for ascites control, laboratory abnormalities, QoL, adverse events, and survival at 12 months. A total of 30 patients (60.0 ± 9.9 years; 57% male; Model for End-Stage Liver Disease score, 11.4 ± 2.7) received an alfapump, mostly by an interventional radiology approach (97%), followed by longterm prophylactic antibiotics. The alfapump removed a mean ascites volume of 230.6 ± 148.9 L/patient at 12 months, dramatically reducing the mean LVP frequency from 2.4 ± 1.4/patient/month before pump implantation to 0.2 ± 0.4/patient/month after pump implantation. All surviving patients had improved QoL (baseline versus 3 months; CLDQ, 3.9 ± 1.21 versus 5.0 ± 1.0; Ascites Q, 51.7 ± 21.9 versus 26.7 ± 18.6; P < 0.001 for both) and a better biochemical index of nutritional status (prealbumin 87.8 ± 37.5 versus 102.9 ± 45.3 mg/L at 3 months; P = 0.04). Bacterial infections (15 events in 13 patients), electrolyte abnormalities (11 events in 6 patients), and renal complications (11 events in 9 patients) were the most common severe adverse events. By 12 months, 4 patients died from complications of cirrhosis. Alfapump insertion may be a definitive treatment for refractory ascites in cirrhosis, especially in patients who are not TIPS candidates.

Adoption of a dedicated multidisciplinary team is associated with improved survival in acute pulmonary embolism.

BACKGROUND: Acute pulmonary embolism remains a significant cause of mortality and morbidity worldwide. Benefit of recently developed multidisciplinary PE response teams (PERT) with higher utilization of advanced therapies has not been established. METHODS: To evaluate patient-centered outcomes and cost-effectiveness of a multidisciplinary PERT we performed a retrospective analysis of 554 patients with acute PE at the university of Virginia between July 2014 and June 2015 (pre-PERT era) and between April 2017 through October 2018 (PERT era). Six-month survival, hospital length-of-stay (LOS), type of PE therapy, and in-hospital bleeding were assessed upon collected data. RESULTS: 317 consecutive patients were treated for acute PE during an 18-month period following institution of a multidisciplinary PE program; for 120 patients PERT was activated (PA), the remaining 197 patients with acute PE were considered as a separate, contemporary group (NPA). The historical, comparator cohort (PP) was composed of 237 patients. These 3 groups were similar in terms of baseline demographics, comorbidities and risk, as assessed by the Pulmonary Embolism Severity Index (PESI). Patients in the historical cohort demonstrated worsened survival when compared with patients treated during the PERT era. During the PERT era no statistically significant difference in survival was observed in the PA group when compared to the NPA group despite significantly higher severity of illness among PA patients. Hospital LOS was not different in the PA group when compared to either the NPA or PP group. Hospital costs did not differ among the 3 cohorts. 30-day re-admission rates were significantly lower during the PERT era. Rates of advanced therapies were significantly higher during the PERT era (9.1% vs. 2%) and were concentrated in the PA group (21.7% vs. 1.5%) without any significant rise in in-hospital bleeding complications. CONCLUSIONS: At our institution, all-cause mortality in patients with acute PE has significantly and durably decreased with the adoption of a PERT program without incurring additional hospital costs or protracting hospital LOS. Our data suggest that the adoption of a multidisciplinary approach at some institutions may provide benefit to select patients with acute PE.

Feasibility and Procedural Safety of alfapump System Implantation by IR: Experience from the MOSAIC Study, a Multicenter, Open-Label Prospective Study in Cirrhotic Patients with Refractory Ascites.

PURPOSE: To evaluate feasibility, procedural outcomes, and safety aspects of implantation of the alfapump system for management of refractory ascites by interventional radiology (IR) methods. MATERIALS AND METHODS: The multicenter open-label prospective MOSAIC study included 29 patients (mean age 60.0 y ± 9.9; range, 32-72 y, 17 [56.7%] male) with cirrhotic refractory ascites who received an alfapump system implanted by IR. The fully subcutaneous alfapump system consists of a pump and 2 silicone catheters, whose distal ends are inserted in the peritoneum and the bladder, respectively. The device moves ascites from the peritoneum to the bladder, reducing the requirement of paracentesis. Pumped volume and speed can be customized as required. The implant procedure was performed under general or local anesthesia. Both catheters were placed under ultrasound guidance. The pump was inserted in a subcutaneous pocket on the upper abdomen. Incidence and severity of procedure-related serious adverse events up to 3 months after implantation were recorded. RESULTS: Technical success was achieved in 29 (100%) IR implant procedures. The pump was usually implanted on the right abdomen (76.7%). In 5 patients, deviation from the Instructions for Use was required. Adverse events (requirement of additional incisions, postoperative bleed) occurred in 3 patients. At 3 months after implantation, 3 possibly procedure-related serious adverse events (ascites leakage, bacterial peritonitis, postoperative bleeding) had occurred. Two explantations (2/29; 6.8%) (cellulitis, pump pocket infection) and 4 reinterventions (pump or catheter replacement) were required, corresponding to an adverse event incidence rate of 9/29 (31.0%). CONCLUSIONS: Placement of the alfapump using IR methods is both feasible and technically successful.

The Role of Interventional Radiologists in the Use of Extracorporeal Membranous Oxygenation in the Catheter-Directed Treatment of Pulmonary Embolism.

Patients with pulmonary embolism who are in hemodynamically unstable condition present a special challenge to the interventionalist. When treating such patients, extracorporeal membranous oxygenation (ECMO) can help to stabilize these patients' condition; however, specific criteria for its use do not exist. Two patients are presented here to familiarize the reader with the use of ECMO and to demonstrate its utility for the interventional radiologist.

Meta-Analysis of Prostatic Artery Embolization for Benign Prostatic Hyperplasia.

PURPOSE: To perform meta-analysis of available data on prostatic artery embolization (PAE). MATERIALS AND METHODS: Meta-analysis was conducted on articles published between November 2009 and December 2015. Peer-reviewed studies with > 5 patients and standard deviations and/or individual-level data on one or more of the following outcomes were included: prostate volume (PV), peak flow rate (Qmax), postvoid residual (PVR), International Prostate Symptom Score (IPSS), quality of life (QOL) score, International Index of Erectile Function (IIEF) score, and prostate-specific antigen (PSA) level. A random-effects meta-analysis was performed on the outcomes at 1, 3, 6, and 12 months after PAE compared with baseline values, with a P < .05 decision rule as the null hypothesis rejection criterion. RESULTS: Nineteen of 268 studies were included in data collection, with 6 included in the meta-analysis. At 12 months, PV decreased by 31.31 cm3 (P < .001), PSA remained unchanged (P = .248), PVR decreased by 85.54 mL (P < .001), Qmax increased by 5.39 mL/s (P < .001), IPSS improved by 20.39 points (P < .001), QOL score improved by -2.49 points (P < .001), and IIEF was unchanged (P = 1.0). There were a total of 218 adverse events (AEs) among 662 patients (32.93%), with 216 being Society of Interventional Radiology class A/B (99%). The most common complications were rectalgia/dysuria (n = 60; 9.0%) and acute urinary retention (n = 52; 7.8%). No class D/E complications were reported. CONCLUSIONS: PAE provided improvement in Qmax, PVR, IPSS, and QOL endpoints at 12 months, with a low incidence of serious AEs (0.3%), although minor AEs were common (32.93%). There was no adverse effect on erectile function.

Prospective, Randomized, Concurrently-Controlled Study of a Stent Graft versus Balloon Angioplasty for Treatment of Arteriovenous Access Graft Stenosis: 2-Year Results of the RENOVA Study.

PURPOSE: To present final, 2-year data from randomized comparison of an expanded polytetrafluoroethylene stent graft (SG) and percutaneous transluminal angioplasty (PTA) for treatment of arteriovenous graft (AVG) anastomotic stenoses. MATERIALS AND METHODS: A 28-site, prospective, controlled US study enrolled 270 patients with malfunctioning AVG anastomotic stenoses of ≥ 50%; 138 patients underwent SG placement, and 132 underwent PTA alone. Follow-up imaging and intervention were event-driven. RESULTS: The study was completed by 191 patients (97 SG, 94 PTA). Five patients were lost to follow-up or withdrew; 74 patients died during the study (38 SG, 36 PTA). At 12 months, treatment area primary patency (TAPP) was SG 47.6% versus PTA 24.8% (P < .001), access circuit primary patency (ACPP) was SG 24% versus PTA 11% (P = .007), and index of patency function (IPF) was SG 5.2 months/intervention ± 4.1 versus PTA 4.4 months/intervention ± 3.5 (P = .009). At 24 months, TAPP was SG 26.9% versus PTA 13.5% (P < .001), ACPP was SG 9.5% versus PTA 5.5% (P = .01), and IPF was SG 7.1 months/intervention ± 7.0 versus PTA 5.3 months/intervention ± 5.2; estimated number of reinterventions before graft abandonment was 3.4 for SG patients versus 4.3 for PTA patients. There were no significant differences in adverse events (P > .05) except for restenosis requiring reintervention rates of 82.6% in PTA patients versus 63.0% in SG patients (P < .001). CONCLUSIONS: At 2 years, SG use provided a sustained, greater than 2-fold advantage over PTA in treatment area and overall access patency. Time to subsequent intervention was longer in the SG group.

Meta-Analysis of Local Endovascular Therapy for Acute Ischemic Stroke.

A meta-analysis was performed to assess randomized controlled trials comparing local endovascular therapy (with and without intravenous thrombolysis) versus standard care (intravenous thrombolysis alone when appropriate) for acute ischemic stroke. Local endovascular therapy showed a significant improvement in functional independence versus standard care (odds ratio, 1.779; 95% confidence interval, 1.262-2.507; P < .001). This benefit strengthened further on subgroup analyses of trials in which a majority of cases used stent retrievers, trials with intravenous thrombolysis use in both arms when appropriate, and trials that required preprocedural imaging of all patients. There were no significant differences between arms in terms of mortality, hemicraniectomy, intracranial hemorrhage, and cerebral edema rates (P > .05). In conclusion, in the treatment of acute ischemic stroke, local endovascular therapy leads to improved functional independence compared with standard care.

Bleeding Risk and Management in Interventional Procedures in Chronic Liver Disease.

The coagulopathy of liver disease is distinctly different from therapeutic anticoagulation in a patient. Despite stable elevated standard clot-based coagulation assays, nearly all patients with stable chronic liver disease (CLD) have normal or increased clotting. Common unfamiliarity with the limitations of these assays in CLD may lead to inappropriate and sometimes harmful interventions, including blood product transfusions before a procedure. Knowledge of the distinct hemostatic alterations in CLD can allow identification of the small subset of patients with clinically significant coagulopathy who can benefit from hematologic optimization before invasive procedures.