Optimal Medical Therapy Following Deep Venous Interventions: Proceedings from the Society of Interventional Radiology Foundation Research Consensus Panel

The optimal medical management of patients following endovascular deep venous interventions remains ill-defined. As such, the Society of Interventional Radiology Foundation (SIRF) convened a multidisciplinary group of experts in a virtual Research Consensus Panel (RCP) to develop a prioritized research agenda regarding antithrombotic therapy following deep venous interventions. The panelists presented the gaps in knowledge followed by discussion and ranking of research priorities based on clinical relevance, overall impact, and technical feasibility. The following research topics were identified as high priority: 1) characterization of biological processes leading to in-stent stenosis/rethrombosis; 2) identification and validation of methods to assess venous flow dynamics and their effect on stent failure; 3) elucidation of the role of inflammation and anti-inflammatory therapies; and 4) clinical studies to compare antithrombotic strategies and improve venous outcome assessment. Collaborative, multicenter research is necessary to answer these questions and thereby enhance the care of patients with venous disease.     

Research Priorities in Percutaneous Image- and Endoscopy-Guided Interventions for Biliary and Gallbladder Diseases: Proceedings from the Society of Interventional Radiology Foundation Multidisciplinary Research Consensus Panel

Recent technological advancements, including the introduction of disposable endoscopes, have enhanced the role of interventional radiology (IR) in the management of biliary and gallbladder diseases. There are unanswered questions in this growing field. The Society of Interventional Radiology Foundation convened a virtual research consensus panel consisting of a multidisciplinary group of experts to develop a prioritized research agenda regarding percutaneous image- and endoscopy-guided procedures for biliary and gallbladder diseases. The panelists discussed current data, opportunities for IR, and future efforts to maximize IR’s ability and scope. A recurring theme throughout the discussions was to find ways to reduce the total duration of percutaneous drains and improve patients’ quality of life. After the presentations and discussions, research priorities were ranked on the basis of their clinical relevance and impact. The research ideas ranked top 3 were as follows: (a) percutaneous multimodality management of benign anastomotic biliary strictures (laser vs endobiliary ablation vs cholangioplasty vs drain upsize protocol alone), (b) ablation of intraductal cholangiocarcinoma with and without stent placement, and (c) cholecystoscopy/choledochoscopy and lithotripsy in nonsurgical patients with calculous cholecystitis. Collaborative, retrospective, and prospective research studies are essential to answer these questions and improve the management protocols for patients with biliary and gallbladder diseases.     

Proceedings from the Society of Interventional Radiology Foundation Research Consensus Panel on Artificial Intelligence in Interventional Radiology: From Code to Bedside

Artificial intelligence (AI)-based technologies are the most rapidly growing field of innovation in healthcare with the promise to achieve substantial improvements in delivery of patient care across all disciplines of medicine. Recent advances in imaging technology along with marked expansion of readily available advanced health information, data offer a unique opportunity for interventional radiology (IR) to reinvent itself as a data-driven specialty. Additionally, the growth of AI-based applications in diagnostic imaging is expected to have downstream effects on all image-guidance modalities. Therefore, the Society of Interventional Radiology Foundation has called upon 13 key opinion leaders in the field of IR to develop research priorities for clinical applications of AI in IR. The objectives of the assembled research consensus panel were to assess the availability and understand the applicability of AI for IR, estimate current needs and clinical use cases, and assemble a list of research priorities for the development of AI in IR. Individual panel members proposed and all participants voted upon consensus statements to rank them according to their overall impact for IR. The results identified the top priorities for the IR research community and provide organizing principles for innovative academic-industrial research collaborations that will leverage both clinical expertise and cutting-edge technology to benefit patient care in IR.     

Interventional Radiology Obesity Therapeutics: Proceedings from the Society of Interventional Radiology Foundation Research Consensus Panel

The Society of Interventional Radiology Foundation commissioned a Research Consensus Panel to establish a research agenda on “Obesity Therapeutics” in interventional radiology (IR). The meeting convened a multidisciplinary group of physicians and scientists with expertise in obesity therapeutics. The meeting was intended to review current evidence on obesity therapies, familiarize attendees with the regulatory evaluation process, and identify research deficiencies in IR bariatric interventions, with the goal of prioritizing future high-quality research that would move the field forward. The panelists agreed that a weight loss of >8%–10% from baseline at 6–12 months is a desirable therapeutic endpoint for future IR weight loss therapies. The final consensus on the highest priority research was to design a blinded randomized controlled trial of IR weight loss interventions versus sham control arms, with patients receiving behavioral therapy.     

Lymphatic Interventional Treatment for Chyluria via Retrograde Thoracic Duct Access

Chyluria is the leakage of intestinal lymph (chyle) into the urine. Novel lymphatic intervention techniques, such as interstitial lymphatic embolization, proved to be a useful treatment option for chyluria. However, one of the challenges of this approach is the difficulty in identifying connections between the lymphatic system and kidney collecting system. Here, embolization of the abnormal lymphatic connection through retrograde thoracic duct access in 3 chyluria patients is introduced.     

Endovascular Lymphatic Decompression via Thoracic Duct Stent Placement for Refractory Ascites in Patients with Cirrhosis: A Pilot Study

PurposeTo evaluate the technical and clinical success of endovascular lymphatic decompression via thoracic duct (TD) stent placement in patients with cirrhosis with refractory ascites.Materials and MethodsNine patients (6 men and 3 women; median age, 66 [interquartile range {IQR}, 65–68] years; range, 62–78 years) who underwent TD stent placement for refractory ascites with contraindications for liver transplantation and transjugular intrahepatic portosystemic shunt creation were included in this retrospective study. TD stent placement was performed under local anesthesia using retrograde access from the venous system. Self-expanding stents from 5 to 8 mm in diameter were used and extended into the subclavian vein by approximately 1 cm. Technical (correct positioning of the stent) and clinical success (no more requirement of paracentesis) were evaluated. In addition, the safety of the procedure and TD pressure evolution were evaluated.ResultsThe technical success rate was 100%, and 3 (33%) patients reported clinical success. Five (56%) patients reported 7 minor adverse events (Grade I), among which 2 TD perforations were induced by stent angioplasty, with no clinical manifestation or treatment required. The median TD pressure decreased from 19 mm Hg (IQR, 11–24 mm Hg) at the beginning of the procedure to 6 mm Hg (IQR, 5–11 mm Hg) after TD stent placement. The median survival time after the procedure was 7.1 months.ConclusionsEndovascular lymphatic decompression via TD stent placement is feasible and safe and was effective on ascites in some patients with cirrhosis with refractory ascites.     

Musculoskeletal Oncologic Interventions: Proceedings from the Society of Interventional Radiology and Society of Interventional Oncology Research Consensus Panel

Musculoskeletal interventions are increasingly used with palliative and curative intent in the multidisciplinary treatment of oncology patients with bone and soft-tissue tumors. There is an unmet need for high-quality evidence to guide broader application and adoption of minimally invasive interventional technologies to treat these patients. Therefore, the Society of Interventional Radiology Foundation and the Society of Interventional Oncology collaborated to convene a research consensus panel to prioritize a research agenda addressing the gaps in the current evidence. This article summarizes the panel’s proceedings and recommendations for future basic science and clinical investigation to chart the course for interventional oncology within the musculoskeletal system. Key questions that emerged addressed the effectiveness of ablation within specific patient populations, the effect of combination of ablation with radiotherapy and/or immunotherapy, and the potential of standardization of techniques, including modeling and monitoring, to improve the consistency and predictability of treatment outcomes.     

Predictors for Nonhome Patient Discharge following Lower Extremity Arterial Interventions

PurposeTo identify the variables associated with patient discharge disposition to optimize postprocedural care and discharge planning following lower extremity arterial interventions for peripheral artery disease (PAD).Materials and MethodsThe 2014–2017 American College of Surgeons National Surgical Quality Improvement Program database was queried using current procedural terminology codes for endovascular infrainguinal interventions for PAD. The main outcome variable of interest was nonhome discharge. Covariates included patient sociodemographic variables, age quartile (upper quartile, ≥77 years), comorbidities (diabetes, renal disease, bleeding disorder, congestive heart failure [CHF], and chronic obstructive pulmonary disease), presence of an open wound before a procedure, type of procedure, operative time, symptom severity, American Society of Anesthesiologists class, and baseline functional status. Univariate analysis and multivariate logistic regression were performed on Stata/SE 15.1.ResultsA total of 3,190 patients met the inclusion criteria, of whom 664 (20.8%) had nonhome discharge. Multivariate regression revealed that age (odds ratio [OR], 1.9 for the upper age quartile [>77 years]; 95% confidence interval [CI], 1.46–2.50), operative time (OR, 1.2 per increase in quartile; 95% CI, 1.09–1.30), preoperative wound (OR, 1.5; 95% CI, 1.24–1.90), renal failure (OR, 1.7; 95% CI, 1.30–2.14), CHF (OR, 2.2; 95% CI, 1.51–3.24), symptom severity (OR, 1.7; 95% CI, 1.46–1.98), and independent functional status (OR, 0.74; 95% CI, 0.59–0.92; P = .007) were associated with nonhome discharge. All P values were ≤.001 unless otherwise stated.ConclusionsProlonged procedural time, the presence of preprocedural wound and patient comorbidities, symptomatology, and baseline functional status may be used to identify patients who will require a nonhome discharge and early discharge planning.     

Experimental VX2 Rabbit Liver Tumor Model in Carbon Tetrachloride–Induced Cirrhosis of the Liver

Liver cirrhosis is a major underlying factor in the development of hepatocellular carcinoma. Currently, there is an unmet need for midsize experimental vertebrate models that would offer reproducible implantable liver tumors in a cirrhotic liver background. This study establishes a protocol for a syngeneic rabbit model of VX2 liver cancer with underlying liver cirrhosis induced using carbon tetrachloride (CCl₄). Male New Zealand white rabbits (n = 3) received CCl₄ by intragastric administration once weekly. Concentrations started at 5% v/v CCl₄ dissolved in olive oil. CCl₄ dosing was progressively increased every week by 2.5% v/v increments for the duration of treatment (16 weeks total). VX2 tumors were then orthotopically implanted into the left hepatic lobe and allowed to grow for 3 weeks. Cross-sectional imaging confirmed the presence of hepatic tumors. Gross and histopathological evaluations showed reproducible tumor growth in the presence of liver cirrhosis in all animals.     

Intranodal Lymphangiography and Embolization for the Treatment of Early Postoperative Lymphatic Leaks after Pelvic Surgery

PurposeTo assess outcome and predictors of outcome after lymphatic embolization (LE) for early postoperative lymphatic leak after pelvic surgery.Material and MethodsLymphangiography (LG) procedures performed between May 2015 and February 2020 for postoperative intraperitoneal lymphatic leaks after pelvic surgery were reviewed. Treatment indication was lymphatic drainage of >500 mL/d persisting for >1 week. LE was performed by injecting glue into the iliac lymph node. Fisher exact and Wilcoxon rank-sum tests were used for comparative analysis, and logistic regression was used to assess predictors of outcome.ResultsLG was performed in 71 patients. A leak was demonstrated in 69 patients who underwent LE. The mean drainage was 1,329 mL/d ± 773. Catheters were removed in 49 (69.0%) patients after 1 procedure and in 69 (97.2%) patients after a mean of 1.3 procedures. The mean drainage at the time of catheter removal was 157 mL/d ± 100. Failure occurred in 12 (16.9%) cases, including 2 (2.8%) cases of unsuccessful catheter removal and 10 (14.1%) cases of catheter reinsertion owing to recurrent ascites (n = 3) and lymphoceles (n = 7). Older age and drainage of >1,500 mL/d were associated with failure (P = .004). Drainage of >1,500 mL/d was associated with a post-LE catheter dwell time of longer than 1 week (P = .024). Minor adverse events were noted in 4 (5.6%) patients who presented with transient leg swelling.ConclusionsLE was effective for treating pelvic surgery-related lymphatic leaks. Reintervention may be required. Drainage of >1,500 mL/d was associated with clinical failure and a post-LE catheter dwell time of longer than 1 week.     

Rendezvous Technique for Advanced Pancreatic Duct Interventions

Interventional radiology can be used to perform complex pancreatic duct (PD) interventions in cases in which PD abnormalities limit the feasibility of an endoscopic approach. A multidisciplinary approach with gastroenterology using the rendezvous technique can improve procedural success. The establishment of through-and-through access to the PD via a combined percutaneous and endoscopic approach can be used when endoscopy alone fails. In this study, 3 cases are presented in which the rendezvous technique was successfully employed to access the PD for subsequent interventions.     

Emergent Transjugular Intrahepatic Portosystemic Shunt as a First-Line Therapy in Patients with Cirrhosis with Acute Gastroesophageal Variceal Hemorrhage

PurposeTo investigate the safety and effectiveness of emergent transjugular intrahepatic portosystemic shunt (TIPS) as first-line therapy in patients with advanced cirrhosis with acute variceal hemorrhage.Materials and MethodsFrom July 2016 to June 2019, 76 patients with advanced cirrhosis and acute variceal hemorrhage were included in this retrospective study. All patients underwent emergent TIPS as first-line therapy within 24 hours. Gastroesophageal varices in patients with cirrhosis were diagnosed with contrast-enhanced computed tomography because emergent endoscopy has not been routinely performed in this center. The primary outcomes were the control rate of bleeding and the rate of rebleeding. Secondary outcomes were the technical success rate of procedure, transplantation-free survival, the mean hospitalization time, the time of stay in the intensive care unit, and adverse events.ResultsAll patients underwent TIPS creation successfully and were transferred to general wards. The median follow-up time was 21.7 months (interquartile range, 12.6–28.1 months). The control rate of bleeding (≤5 days) was 100%. The rates of early (>5 days to 6 weeks) and late (>6 weeks to 2 years) rebleeding were 6.6% and 1.3%, respectively. The 6-week, 1-year, and 2-year transplantation-free survival rates were 94.7%, 93.4%, and 84.6%, respectively. The incidences of acute liver failure, hepatic encephalopathy, and shunt dysfunction were 5.3%, 25%, and 5.3%, respectively.ConclusionsEmergent TIPS as a first-line therapy in patients with advanced cirrhosis with acute variceal hemorrhage is safe and effective. This study provides an alternative approach for medical centers without emergent endoscopy facility to manage the condition.     

Internet Search Trends Relevant to Interventional Oncology: A Google Trends Study (2004–2020)

Interventional Radiology (IR) procedures addressing cancer have been grouped in the subspecialty of interventional oncology and represent an important component of modern multidisciplinary cancer care. This study pinpoints temporal and geographical trends of public online searches for terms related to the field, as well as IR-related cancer therapies. Google Trends data were analyzed for long-term (2004–2020) trends in the United States and worldwide. Overall, search interest for IR increased throughout the United States but decreased globally. Specific search volumes for cancer-related IR techniques such as radioembolization and chemoembolization therapies increased by 2.8- and 2.5-fold, respectively, in the United States, whereas the search volumes for ablation techniques remained steady or decreased. Future research and advocacy may focus on increasing public awareness of the field.     

Irreversible Electroporation for Hepatic Tumors: Protocol Standardization Using the Modified Delphi Technique

PurposeA consensus study of panelists was performed to provide a uniform protocol regarding (contra) indications, procedural parameters, perioperative care, and follow-up of irreversible electroporation (IRE) for the treatment of hepatic malignancies.Materials and MethodsInterventional radiologists who had 2 or more publications on IRE, reporting at least 1 patient cohort in the field of hepatobiliary IRE, were recruited. The 8 panelists were asked to anonymously complete 3 iterative rounds of IRE-focused questionnaires to collect data according to a modified Delphi technique. Consensus was defined as having reached 80% or greater agreement.ResultsPanel members’ response rates were 88%, 75%, and 88% in rounds 1, 2, and 3, respectively; consensus was reached on 124 of 136 items (91%). Percutaneous or intraoperative hepatic IRE should be considered for unresectable primary and secondary malignancies that are truly unsuitable for thermal ablation because of proximity to critical structures. Absolute contraindications are ventricular arrhythmias, cardiac stimulation devices, and congestive heart failure of New York Heart Association class 3 or higher. A metal stent outside the ablation zone should not be considered a contraindication. For the only commercially available IRE device, the recommended settings are an inter-electrode distance of 10–20 mm and an exposure length of 20 mm. After 10 test pulses, 90 treatment pulses of 1500 V/cm should be delivered continuously, with a pulse length of 70–90 μs. The first post-procedural follow-up should take place 1 month after IRE and thereafter every 3 months, using cross-sectional imaging plus tumor marker assessment.ConclusionsThis article provides recommendations, created by a modified Delphi consensus study, regarding patient selection, workup, procedure, and follow-up of IRE treatment for hepatic malignancies.     

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.     

A Practical Guide to Use of Publicly Available Data Sets for Observational Research in Interventional Radiology

Observational data research studying access, utilization, cost, and outcomes of image-guided interventions using publicly available “big data” sets is growing in the interventional radiology (IR) literature. Publicly available data sets offer insight into real-world care and represent an important pillar of IR research moving forward. They offer insights into how IR procedures are being used nationally and whether they are working as intended. On the other hand, large data sources are aggregated using complex sampling frames, and their strengths and weaknesses only become apparent after extensive use. Unintentional misuse of large data sets can result in misleading or sometimes erroneous conclusions. This review introduces the most commonly used databases relevant to IR research, highlights their strengths and limitations, and provides recommendations for use. In addition, it summarizes methodologic best practices pertinent to all data sets for planning and executing scientifically rigorous and clinically relevant observational research.     

Combining Laparoscopic Liver Partitioning and Simultaneous Portohepatic Venous Deprivation for Rapid Liver Hypertrophy

Future liver remnant (FLR) volume is an important indicator of the risk of posthepatectomy liver failure (PHLF) and limits the feasibility of major hepatectomies. A case series of 5 patients treated with a novel approach is presented. Laparoscopic liver partitioning was combined with subsequent liver venous deprivation (embolization of both the portal and the hepatic veins). Baseline average FLR was 28.8%. All procedures were successfully performed without major complications. Mean 1-, 2- and 4-week hypertrophy of the FLR were 35%, 40.3%, and 46.4%, respectively. Four patients underwent planned surgery after a mean interval of 28 days. Of these, 2 patients achieved sufficient FLR volume and function after 2 weeks and underwent surgery before the 4-week volumetric analysis. One patient did not undergo surgery because of intraoperative diagnosis of peritoneal metastases. No cases of PHLF were observed at 5-day follow-up.     

Use of Contrast-Enhanced Ultrasound to Determine Thoracic Duct Patency

The aim of this study was to determine the feasibility of using contrast-enhanced ultrasound (CEUS) evaluation to determine thoracic duct (TD) outlet patency. Nine patients referred for lymphatic imaging and intervention underwent percutaneous intranodal ultrasound contrast injection and conventional lymphangiography (CL). Eight of 9 patients had a patent TD by CEUS and CL. One patient did not have a patent TD. There was 100% agreement between CEUS and CL. These results suggest that CEUS is an imaging modality that might be as accurate as CL in determining TD patency.     

Intranodal Glue Embolization for Postoperative Lymphatic Leaks in the Groin and Pelvis: Comparison with Sclerotherapy

PurposeTo compare the effectiveness of and adverse events related to intranodal glue embolization (IGE) with those of intracavitary sclerotherapy for the treatment of postoperative groin and pelvic lymphatic leaks.Materials and MethodsFrom November 2015 to July 2021, IGE for postoperative pelvic or groin lymphocele or lymphorrhea was performed in 33 patients. From January 2010 to July 2021, 28 patients with postoperative pelvic or groin lymphocele were treated with sclerosis alone. Clinical success was defined as resolution of drainage within 3 weeks of the last intervention performed without recurrence. Patients presenting >1 year after surgery or with <30 days of follow-up were excluded. Patients with lymphorrhea treated with IGE were not statistically compared with those in the sclerosis group because they were not eligible for sclerosis.ResultsClinical success was similar between the groups (lymphocele IGE, 15/18, 83.3%, vs sclerosis, 15/23, 65.2% [P = .29]; lymphorrhea IGE, 8/9, 88.9%). The mean number of interventions performed to successfully treat a lymphocele was significantly higher in the sclerosis group (2.5 for sclerosis vs 1.3 for IGE; P = .003; lymphorrhea IGE, 1.0). The mean time to resolution was significantly longer for sclerosis than for IGE (27 vs 7 days; P = .002; 4 days for lymphorrhea IGE). There were no sclerosis-related adverse events and 2 IGE-related adverse events: (a) 1 case of mild lymphedema and (b) 1 case of nontarget embolization resulting in deep vein thrombosis.ConclusionsFor treatment of postoperative pelvic and groin lymphoceles, IGE results in faster resolution with fewer interventions compared with sclerosis. IGE is also an effective treatment for postoperative groin lymphorrhea.