Society of Interventional Radiology Quality Improvement Standards for Percutaneous Transcatheter Embolization

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.

Double-Balloon Catheter-Mediated Transarterial Chemotherapy Delivery in a Swine Model: A Mechanism Recruiting the Vasa Vasorum for Localized Therapies

PURPOSE

Treatment of hypovascular tumors, such as pancreatic adenocarcinoma, is challenging owing to inefficient drug delivery. This report examines the potential mechanism of localized drug delivery via transarterial microperfusion (TAMP) using a proprietary adjustable double-balloon occlusion catheter in a porcine model.

MATERIALS AND METHODS

Adult Yorkshire swine (N = 21) were used in the Institutional Animal Care & Use Committee-approved protocols. The RC-120 catheter (RenovoRx, Los Altos, California) was positioned into visceral, femoral, and pulmonary arteries with infusion of methylene blue dye, gemcitabine, or gold nanoparticles. Transmural delivery was compared under double-balloon occlusion with and without side-branch exclusion, single-balloon occlusion, and intravenous delivery. Intra-arterial pressure and vascular histologic changes were assessed.

RESULTS

Infusion with double-balloon occlusion and side-branch exclusion provided increased intra-arterial pressure in the isolated segment and enhanced perivascular infusate penetration with minimal vascular injury. Infusates were predominantly found in the vasa vasorum by electron microscopy.

CONCLUSIONS

TAMP enhanced transmural passage mediated by localized increase in arterial pressure via vasa vasorum.

Stent-Graft Placement for Hepatic Arterial Hemorrhage after Pancreaticobiliary Surgery: Long-Term Clinical Outcomes

PURPOSE

To evaluate the safety and long-term clinical outcomes of stent-graft placement to treat hepatic arterial hemorrhage after pancreaticobiliary surgery.

MATERIALS AND METHODS

Outcomes were retrospectively evaluated in 61 patients (50 men and 11 women; mean age, 63 years) who underwent stent-graft placement for delayed arterial hemorrhage (after 24 hours) after pancreaticobiliary surgery from 2006 to 2023. Bleeding sites included the gastroduodenal artery stump (n = 54), common or proper hepatic artery (n = 5), and right hepatic artery (n = 2). The stent-grafts used were Viabahn (n = 27), Comvi (n = 11), Jostent (n = 3), Covera (n = 11), and Lifestream (n = 7). Technical and clinical success and adverse events (AE) were evaluated. After stent-graft placement, overall survival (OS), hemorrhage-free survival (HFS), and stent patency were evaluated.

RESULTS

The technical and clinical success rates of stent-graft placement were 97% and 93%, respectively. The severe AE rate was 12% and was significantly higher in patients who underwent pylorus-sacrificing rather than pylorus-preserving surgery (P = .001). None of the severe AEs were associated with patient mortality. Median OS after stent-graft placement was 854 days, and median HFS was 822 days. The 1-, 3-, 5-, and 10-year stent patency rates were 87%, 84%, 79%, and 72%, respectively.

CONCLUSIONS

Stent-graft placement was safe and provided long-term control of hepatic arterial hemorrhage after pancreaticobiliary surgery.

Ultrasound-guided genitofemoral nerve block for femoral arterial access gain and closure: a randomized controlled trial

OBJECTIVES

This study aimed to compare the analgesic efficacy and safety of the femoral branch block of the genitofemoral nerve (FBB) versus local infiltration anesthesia (LIA) for femoral arterial access gain and closure.

METHODS

Eighty-two patients (age, 64.8 ± 10.9 years; female, 30.5%) undergoing endovascular procedures using 5-Fr femoral sheath were assigned to either FBB (n = 41) or LIA (n = 41). In both groups, 2% lidocaine HCL with 1:100,000 epinephrine was used as an anesthetic solution. Pain scores during access gain and closure were evaluated using a visual analog scale (score 0-10), patient satisfaction levels with the quality of anesthesia were scored on a 7-point Likert scale, and adverse events were recorded.

RESULTS

The primary endpoint, pain scores during access closure, was significantly lower in the FBB group than in the LIA group (0.1 ± 0.37 vs 1.73 ± 0.92; p < 0.001). The FBB group also had significantly lower pain scores during access gain compared to the LIA group (0.83 ± 0.83 vs 2.78 ± 1.26; p < 0.001). There was an inverse relationship between pain scores and FBB after adjustment for age, gender, and body mass index (p < 0.001). FBB group reported significantly higher satisfaction with anesthesia quality compared to the LIA group (6.49 ± 0.64 vs 4.05 ± 1.05; p < 0.001). No complications were recognized in either group.

CONCLUSIONS

Ultrasound-guided genitofemoral nerve blocks offered better acute pain relief and higher patient satisfaction than LIA during femoral arterial access gain and closure.

CLINICAL RELEVANCE STATEMENT

In this prospective randomized controlled trial, ultrasound-guided genitofemoral nerve blocks offered better acute pain relief than local infiltration anesthesia, resulting in enhanced patient satisfaction.

KEY POINTS

• FBB provided better pain relief during access gain and closure than LIA. • FBB offered higher patient satisfaction with the quality of anesthesia than LIA. • No anesthesia-related or access site complications were recognized in either treatment group.

Hepatic Hypertrophy in Normal and Cirrhotic Livers Following Portal Vein Embolization: Comparative Assessment of 2 Different Embolic Regimens in a Large Animal Model

PURPOSE

To compare the mechanistic effects and hypertrophy outcomes using 2 different portal vein embolization (PVE) regimens in normal and cirrhotic livers in a large animal model.

METHODS AND MATERIALS

The Institutional Animal Care and Use Committee approved all experiments conducted in this study. Fourteen female Yorkshire pigs were separated into a cirrhotic group (CG, n = 7) and non-cirrhotic group (NCG, n = 7) and further subgrouped into those using microspheres and coils (MC, n = 3) or n-butyl cyanoacrylate (nBCA, n = 3) and their corresponding controls (each n = 1). A 3:1 ethiodized oil and ethanol mixture was administered intra-arterially in the CG to induce cirrhosis 4 weeks before PVE. Animals underwent baseline computed tomography (CT), PVE including pre-PVE and post-PVE pressure measurements, and CT imaging at 2 and 4 weeks after PVE. Immunofluorescence stainings for CD3, CD16, Ki-67, and caspase 3 were performed to assess immune cell infiltration, hepatocyte proliferation, and apoptosis. Statistical significance was tested using the Student's t test.

RESULTS

Four weeks after PVE, the percentage of future liver remnant (FLR%) increased by 18.8% (standard deviation [SD], 3.6%) vs 10.9% (SD, 0.95%; P < .01) in the NCG vs CG. The baseline percentage of standardized future liver remnant (sFLR%) for the controls were 41.6% for CG vs 43.6% for NCG. Based on the embolic agents used, the sFLR% two weeks after PVE was 58.4% (SD, 3.7%) and 52.2% (SD, 0.9%) (P < .01) for MC and 46.0% (SD, 2.2%) and 47.2% (SD, 0.4%) for nBCA in the NCG and CG, respectively. Meanwhile, the sFLR% 4 weeks after PVE was 60.5% (SD, 3.9%) and 54.9% (SD, 0.8%) (P < .01) and 60.4% (SD, 3.5%) and 54.2% (SD, 0.95%) (P < .01), respectively. Ki-67 signal intensity increased in the embolized lobe in both CG and NCG (P < .01).

CONCLUSIONS

This preclinical study demonstrated that MC could be the preferred embolic of choice compared to nBCA when a substantial and rapid FLR increase is needed for resection, in both cirrhotic and non-cirrhotic livers.

Outcomes after Genicular Artery Embolization Vary According to the Radiographic Severity of Osteoarthritis: Results from a Prospective Single-Center Study

This prospective single-center study compared outcomes after genicular artery embolization (GAE) in people with mild radiographic knee osteoarthritis (OA) (n = 11) versus moderate to severe radiographic knee OA (n = 22). The mild OA group was older and had experienced symptoms for less time (P < .05). All participants underwent complete embolization of neovessels from genicular arteries. The primary outcome was the proportion of responders at 6 months according to predetermined improvements in pain, function, and/or global change. Results indicated that a higher proportion of participants (n = 9, 81.8%) with mild OA fulfilled responder criteria after treatment compared with people with moderate to severe OA (n = 8, 36.4%) (P = .014). Secondary outcomes for pain, quality of life, and global change were also better in the mild OA group (P < .05). No serious adverse events occurred, including the absence of osteonecrosis on magnetic resonance imaging. The study demonstrated that outcomes after GAE varied according to the severity of baseline radiographic OA.

Endovascular Treatment of Visceral Artery Pseudoaneurysms with Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs)

Background and Objectives: Treatment of visceral artery pseudoaneurysms (VAPs) is always indicated regardless of their diameters, as their risk of rupture is significantly higher than that of visceral artery aneurysms. The invasiveness of surgery and its associated complications have led to a shift in favor of radiological interventions as the initial treatment of choice. However, there are still some unanswered questions on endovascular treatment of VAPs regarding the optimal endovascular technique and the efficacy and safety outcomes. The purpose of this multicenter study was to retrospectively evaluate the effectiveness and safety of endovascular treatment of visceral pseudoaneurysms using Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs). Materials and Methods: Consecutive patients who underwent endovascular embolization with EVOH-based NALEAs for visceral artery pseudoaneurysms between January 2018 and June 2023 were retrospectively evaluated. Results: 38 embolizations were performed. Technical success was achieved in all patients. The clinical success rate was high (92.1% overall), with no significant differences between ruptured and unruptured VAPs (p = 0.679). Seven patients (18.4%) experienced procedure-related complications, related to one case of non-target embolization, four splenic abscesses due to end-organ infarction, and two femoral pseudoaneurysms. The rates of procedure-related complications, end-organ infarction, and vascular access-site complications did not significantly differ between ruptured and unruptured VAPs (p > 0.05). Conclusions: Both ruptured and unruptured visceral pseudoaneurysms can be effectively and safely treated with NALEA-based endovascular embolization. We suggest considering the use of NALEAs, particularly in specific clinical cases that highlight their advantages, including patients with coagulopathy, fragile vessels, and embolization targets that are located at a considerable distance from the microcatheter tip and are otherwise difficult to reach.

The prominent role of percutaneous transarterial embolization in the treatment of anterior abdominal wall hematomas: the results of three high volume tertiary referral centers

PURPOSE

Percutaneous transarterial embolization (PTE) represents a fast, safe and effective option for life-threatening anterior abdominal wall hematomas (AWHs) and those unresponsive to conservative treatment. Our study aims to assess cumulative results of safety, technical and clinical success of PTE performed in three high-volume tertiary referral centers and to evaluate the efficacy of the different embolic materials employed.

MATERIALS AND METHODS

A consecutive series of 124 patients (72.8 ± 14.4 years) with AWHs of different etiology submitted to PTE were retrospectively collected and analyzed. Clinical success, defined as absence of recurrent bleeding within 96 h from PTE, was considered as primary endpoint. The results of the comparison of three groups based on embolic agent employed were also analyzed.

RESULTS

Spontaneous AWHs accounted for 62.1%, iatrogenic for 21.8% and post-traumatic for 16.1% of cases. SARS-CoV-19 infection was present in 22.6% of patients. The most commonly embolized vessels were epigastric inferior artery (n = 127) and superior epigastric artery (n = 25). Technical and clinical success were 97.6 and 87.1%, respectively. Angiographic signs of active bleeding were detected in 85.5% of cases. Four (4%) major complications were reported. The comparison of the three groups of embolic agents (mechanical, particulate/fluid and combined) showed no statistically significant differences in terms of clinical success. SARS-CoV-2 infection was found to be an independent factor for recurrent bleeding and poor 30-day survival.

CONCLUSION

PTE performed with all the embolic agent employed in our centers is a safe and effective tool in the treatment of life-threatening anterior AWH of each origin.

Transcatheter Arterial Embolization for Bleeding Related to Pelvic Trauma: Comparison of Technical and Clinical Results between Hemodynamically Stable and Unstable Patients

BACKGROUND

Endovascular intervention is now the primary line of therapy for arterial injury brought on by pelvic trauma since it can significantly reduce considerable morbidity associated with surgery and can swiftly access and control bleeding sites. Despite international guidelines and widespread awareness of the role of angioembolization in clinical practice, robust evidence comparing the outcomes of angioembolization in hemodynamically stable and unstable patients is still lacking. This study aims to directly compare the outcomes of angioembolization for the treatment of pelvic traumatic arterial injury in patients with hemodynamic stability vs. hemodynamic instability.

METHODS

In our multicenter retrospective investigation, we analyzed data from consecutive patients who underwent, from January 2020 to May 2023, angioembolization for traumatic pelvic arterial injury.

RESULTS

In total, 116 angioembolizations were performed. Gelatin sponges (56.9%) and coils (25.9%) were the most widely used embolic agents. The technical and clinical success rates were 100% and 91.4%, respectively. No statistically significant differences were observed between the two groups in terms of technical success, clinical success, procedure-related complication rate, or 30-day bleeding-related mortality.

CONCLUSIONS

Angioembolization is an effective and safe option for the management of traumatic pelvic arterial lesions even in hemodynamically unstable patients, despite technical variations such as greater use of prophylactic angioembolization.

A Multicenter Retrospective Cohort Study Evaluating the Clinical Outcomes of Patients with Coagulopathy Undergoing Transcatheter Arterial Embolization (TAE) for Acute Non-Neurovascular Bleeding

Background and Objectives: Transcatheter arterial embolization (TAE) is the mainstay of treatment for acute major hemorrhage, even in patients with coagulopathy and spontaneous bleeding. Coagulopathy is associated with worsening bleeding severity and higher mortality and clinical failure rates. Furthermore, some unanswered questions remain, such as the definition of coagulopathy, the indication for TAE or conservative treatment, and the choice of embolic agent. This study aims to assess the efficacy and safety of TAE for spontaneous non-neurovascular acute bleeding in patients with coagulopathy. Materials and Methods: This study is a multicenter analysis of retrospectively collected data of consecutive patients with coagulopathy who had undergone, from January 2018 to May 2023, transcatheter arterial embolization for the management of spontaneous hemorrhages. Results: During the study interval (January 2018-May 2023), 120 patients with coagulopathy underwent TAE for spontaneous non-neurovascular acute bleeding. The abdominal wall was the most common bleeding site (72.5%). The most commonly used embolic agent was polyvinyl alcohol (PVA) particles or microspheres (25.0%), whereas coils and gelatin sponge together accounted for 32.5% of the embolic agents used. Technical success was achieved in all cases, with a 92.5% clinical success rate related to 9 cases of rebleeding. Complications were recorded in 12 (10%) patients. Clinical success was significantly better in the group of patients who underwent correction of the coagulopathy within 24 h of TAE. Conclusions: Transcatheter arterial embolization (TAE) is effective and safe for the management of acute non-neurovascular bleeding in patients with coagulopathy. Correction of coagulopathy should not delay TAE and vice versa, as better clinical outcomes were noted in the subgroup of patients undergoing correction of coagulopathy within 24 h of TAE.

Transcatheter Arterial Embolization (TAE) of Cancer-Related Bleeding

Background and Objectives: Roughly 10% of cancer patients experience an episode of bleeding. The bleeding severity can range from occasional trivial bleeds to major bleeding. The treatment for the bleeding may vary, depending on the clinical condition and anatomical site, and may include various strategies, among which TAE is a cornerstone of major bleeding management. However, the existing literature on tumor hemorrhages is inconsistent. The objective of this multicenter retrospective cohort study was to evaluate the effectiveness and safety of arterial embolization in the treatment of tumor hemorrhages in patients with solid cancers. Materials and Methods: The data for patients with solid cancers undergoing TAE for the management of tumor hemorrhages from January 2020 to May 2023 were gathered. Results: A total of 92 patients with cancer-related bleeding were treated between January 2020 and May 2023. No bleeding was detected by X-ray angiography (XA) in 12 (13%) cases; therefore, a blind embolization was performed. The most common bleeding site was the liver (21.7%). A total of 66 tumor hemorrhages were spontaneous. The most commonly used embolic agent was polyvinyl alcohol (PVA) particles (30.4%). Technical success was achieved in 82 (89.1%) cases, with an 84.8% clinical success rate related to 14 cases of rebleeding. Proximal embolization was performed for 19 (20.7%) patients. Complications were recorded for 10 (10.9%) patients. The 30-day bleeding-related mortality was 15.2%. The technical success, clinical success, proximal embolization rate, and 30-day rebleeding were worse in the subset of patients undergoing TAE with coils. Conclusions: Transcatheter arterial embolization (TAE) represents a viable and potentially life-saving therapeutic approach in the management of tumor hemorrhages, demonstrating a notable effectiveness and safety. The TAE of bleeding tumors using coils resulted in a higher rate of non-superselective proximal embolization, with a trend toward lower clinical success rates and higher rebleeding episodes.

Transcatheter Arterial Embolization (TAE) in the Management of Bleeding in the COVID-19 Patient

Background and Objectives: Increasing attention is being paid to the coagulation disorders associated with SARS-CoV-2 infection. Bleeding accounts for 3-6% of COVID-19 patient deaths, and is often a forgotten part of the disease. The bleeding risk is enhanced by several factors, including spontaneous heparin-induced thrombocytopenia, thrombocytopenia, the hyperfibrinolytic state, the consumption of coagulation factors, and thromboprophylaxis with anticoagulants. This study aims to assess the efficacy and safety of TAE in the management of bleeding in COVID-19 patients. Materials and Methods: This multicenter retrospective study analyzes data from COVID-19 patients subjected to transcatheter arterial embolization for the management of bleeding from February 2020 to January 2023. Results: Transcatheter arterial embolization was performed in 73 COVID-19 patients for acute non-neurovascular bleeding during the study interval (February 2020-January 2023). Coagulopathy was observed in forty-four (60.3%) patients. The primary cause of bleeding was spontaneous soft tissue hematoma (63%). A 100% technical success rate was recorded; six cases of rebleeding resulted in a 91.8% clinical success rate. No cases of non-target embolization were observed. Complications were recorded in 13 (17.8%) patients. The efficacy and safety endpoints did not differ significantly between the coagulopathy and non-coagulopathy groups. Conclusions: Transcatheter Arterial Embolization (TAE) is an effective, safe and potentially life-saving option for the management of acute non-neurovascular bleeding in COVID-19 patients. This approach is effective and safe even in the subgroup of COVID-19 patients with coagulopathy.

Endovascular embolization of visceral artery aneurysm: a retrospective study

To assess the safety and efficacy of endovascular embolization techniques, we compared the short- to medium-term prognosis of coil embolization for symptomatic visceral aneurysms (SVAA) and asymptomatic visceral aneurysms (ASVAA) to identify risk factors associated with 30-day mortality. Explore the symptom profile and intrinsic associations of SVAA. A retrospective study of 66 consecutive patients at two tertiary care hospitals from 2010 to 2020 compared the short- to mid-term outcomes of 22 symptomatic VAAs and 44 asymptomatic VAAs treated with coil embolization. Univariate and log-rank tests were used to analyze the prognostic impact of SVAA and ASVAA. SVAA group had significantly higher 30-day mortality than ASVAA group (2(9.1%) vs 0, P = 0.042), both patients who died had symptomatic pseudoaneurysms. Perioperative complications such as end-organ ischemia (P = 0.293) and reintervention (P = 1) were similar in both groups. No difference in event-free survival was identified between the two groups (P = 0.900), but we found that the majority of pseudoaneurysms were SVAA (4/5) and that they had a much higher event rate than true aneurysms. In addition, dyslipidemia may be an influential factor in the development of VAA (P = 0.010). Coil embolization is a safe and effective method of treatment for VAA. Most pseudoaneurysms have symptoms such as abdominal pain and bleeding, and in view of their risk, more attention should be paid to symptomatic patients and the nature of the aneurysm should be determined as soon as possible to determine the next stage of treatment.

Efficacy and Safety of Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs) in Transcatheter Arterial Embolization (TAE) of Acute Non-Neurovascular Bleeding: A Multicenter Retrospective Cohort Study

Background and Objectives: Transcatheter arterial embolization (TAE) is part of the daily practice of most interventional radiologists worldwide. The ideal liquid embolic agent is far from being identified. Non-adhesive liquid embolic agents (NALEA) harden from the outside to the inside, resulting in deep penetration, known as "magma-like" progression, which permits a more distal embolization with good control of the embolic material. This multicenter retrospective cohort study aims to assess the efficacy, feasibility and safety of transcatheter arterial embolization (TAE) with ethylene-vinyl alcohol (EVOH)-based NALEAs (Onyx and Squid) in acute bleeding outside of the neurovascular area. Materials and Methods: This study is a multicenter analysis of retrospectively collected data of consecutive patients who had undergone, from January 2015 to December 2022, transcatheter arterial embolization with non-adhesive EVOH-based agents in the setting of acute non-neurovascular bleeding. Results: Fifty-three patients underwent transcatheter arterial embolization for acute non-neurovascular bleeding. Eight (15.1%) procedures were performed in patients with coagulopathy. The most used concentration of EVOH-based NALEAs was 34 (i.e., 8%), with a mean dose of 0.5 (±0.3) mL. The mean CT-to-groin time, the mean procedure time, the mean CT-to-embolization time and the mean fluoroscopy time were 22.9 (±12.4) min, 27.5 (±7) min, 50.3 (±13.1) min and 7.5 (±2.8) min, respectively. Technical success was achieved in all cases with a 96.2% clinical success rate. Complications were recorded in six (11.3%) patients. No statistically significant differences were observed between the group of patients with coagulopathy and the group of patients without coagulopathy in terms of efficacy and safety endpoints. Conclusions: Transcatheter arterial embolization (TAE) performed with non-adhesive EVOH-based embolic agents is an effective, feasible and safe strategy for the management of acute non-neurovascular bleeding, even in the subgroup of patients with coagulopathy.

Comparison of Bronchial Artery Embolisation Versus Conservative Treatment for Bronchiectasis-Related Nonmassive Haemoptysis: A Single-Centre Retrospective Study

OBJECTIVE

To compare the safety and effectiveness between bronchial artery embolisation (BAE) and conservative treatment for bronchiectasis-related nonmassive haemoptysis patients.

MATERIALS AND METHODS

From January 2015 to December 2020, consecutive bronchiectasis-related nonmassive haemoptysis patients who underwent either BAE (n = 98) or conservative treatment (n = 118) were included. Treatment-related complications, length of hospital stays, clinical success rate, patient satisfaction, and recurrence-free survival rates were compared between groups. Prognostic factors related to recurrence were also analysed.

RESULTS

During a median follow-up time of 44.8 months (range, 2.4-83.6 months), 34 and 66 patients in the BAE and conservative treatment groups suffered relapse. The 1-year, 2-year, 3-year and 5-year haemoptysis-free survival rates in the BAE and conservative treatment groups were 79.2%, 68.1%, 62.8%, and 57.6% and 64.0%, 52.8%, 44.1%, and 37.0%, respectively (P = 0.007). The minor complication rate after BAE was higher than that after conservative treatment (23/98 vs. 12/118, P = 0.008). BAE was associated with shorter hospital stays (5.0 vs. 7.0 days, P = 0.042) and higher patient satisfaction (88.8% vs. 74.6%, P = 0.008) than those for conservative treatment and with comparable clinical success rates (95.9% vs. 91.5%, P = 0.192). Treatment type, haemoptysis duration, and bronchiectasis severity were independently significant predictors of recurrence for these patients.

CONCLUSIONS

BAE could be another option for bronchiectasis-related nonmassive haemoptysis patients. In the patients with longer duration and more severe bronchiectasis, BAE still appeared to have better long-term haemoptysis control than conservative therapy.

Iatrogenic Renal Artery Injury in 90 Cases: Arteriographic Findings and Outcomes after Embolization for Bleeding

PURPOSE

To evaluate differences in arteriographic findings and outcomes after embolization among patients with a suspected iatrogenic renal arterial injury (IRAI).

MATERIALS AND METHODS

Patients at the authors' institution who underwent renal arteriography for suspected IRAIs after partial nephrectomy, biopsy, or percutaneous access over a 20-year period were included. Records, imaging, and outcomes were reviewed. Data analysis was performed using the Fisher exact or Kruskal-Wallis test.

RESULTS

Ninety arteriograms were performed on 83 patients after partial nephrectomy (n = 32), biopsy (n = 27), or percutaneous access (n = 24), including for nephrostomy/ureterostomy and stone removal. The median number of days between the index procedure and arteriogram was highest (15 days) after partial nephrectomy and lowest (5 days) after biopsy (P = .0001). Embolization was performed during 76% of arteriograms. If prearteriographic imaging showed positive results for IRAIs, embolization was performed in 67% versus 33% if imaging showed negative results (P = .005). The transfusion rate was higher after biopsy than after partial nephrectomy or percutaneous access (P = .002). Acute kidney injury after arteriogram occurred in 7% of patients; however, all returned to baseline by 1 week.

CONCLUSIONS

Despite the different mechanism of IRAIs in partial nephrectomy, biopsy, and percutaneous access, arteriographic findings and outcomes were overall similar among groups. Prearteriographic imaging can help identify IRAIs but cannot supersede the clinical judgment regarding indication for embolization. IRAIs can present acutely or after a long interim, although patients who underwent biopsy presented earlier and more frequently required a blood transfusion. IRAIs can be treated with embolization without permanent deleterious effects on renal function.

Material characterization of GPX®: A versatile in situ solidifying embolic platform technology

Endovascular embolization is a minimally invasive procedure during which blood flow to targeted tissues is selectively occluded. The list of clinical indications for embolization continues to expand. Liquid embolic agents are injectable compositions that transition into a solid or semi-solid form when introduced into blood vessels. The mechanism that triggers the liquid-to-solid transition is a key distinguishing feature of liquid embolic agents. GPX is a waterborne liquid embolic agent comprising oppositely charged polyelectrolytes: polyguanidinum and inorganic polyphoshate. In situ solidification is driven by electrostatic condensation of the polyelectrolytes, triggered by ionic strength differentials. We report in vitro characterization of the material properties of GPX, it is in vivo effectiveness in acute animal studies, and its potential for chemoembolization. The viscosity of GPX can be varied over a wide range by adjusting the polyguanidinium MW and/or concentration. Formulation of GPX with either tantalum microparticles (30 wt%) or iodinated radiocontrast agents (300 mgI ml^-1) did not significantly change the flow behavior of GPX; the viscosity was independent of shear rate and remained within a clinically practical range (80-160 cP). Formulation of GPX with doxorubicin substantially increased viscosity at low shear rates and resulted in a power law dependence on shear rate. High contrast and effective vascular occlusion were demonstrated in both swine kidneys and rete mirabile. Contrast from iodinated compounds was temporary, dissipating within hours. The doxorubicin in vitro release profile was linear over 90 days. The results demonstrate that GPX is a versatile liquid embolic platform that can be formulated with a wide range of viscosities injectable at clinically practical flow rates, with either transient or permanent contrast, and that can provide prolonged zero-order delivery of doxorubicin to embolized tissues.

Results from the First-in-Human Study of the Caterpillar™ Arterial Embolization System

PURPOSE

To assess occlusion success and adverse events associated with the use of a self-expanding device for peripheral artery embolization.

METHODS

This prospective, single-arm, feasibility study was conducted using the Caterpillar™ Arterial Embolization Device composed of opposing nitinol fibers and a flow-occluding membrane. Twenty patients (24 embolization sites) were treated at four investigational centers in New Zealand and Australia and followed for 30 days. Embolization sites included mesenteric, accessory renal, and iliac arteries and their branches. Primary outcome measures were peri-procedural occlusion confirmed by angiography and freedom from device-related serious adverse events (SAEs) at 30 days. Secondary observations included time to occlusion and assessment of adverse events.

RESULTS

Peri-procedural occlusion was 100%, and freedom from a device-related SAE was 94.7% at 30 days. One patient had abdominal bloating that required hospitalization deemed possibly related to the device or procedure. Twenty-two of 24 embolization sites were occluded with one device (91.7%). Mean procedure duration was 11.7 ± 8.6 min (device deployment time: 1.8 ± 1.0 min), and mean fluoroscopy time was 241 ± 290.7 s. All embolization sites occluded during the procedure with 62.5% occluded within three minutes and 91.6% occluded within ten minutes. No devices migrated or required re-embolization. Freedom from device- and procedure-related adverse events was 84.2%. One patient died from aortic rupture during a subsequent adjunctive abdominal aortic endovascular procedure deemed unrelated to the embolization device or procedure.

CONCLUSIONS

This first-in-human study of the Caterpillar embolization device achieved peri-procedural occlusion in all patients with a 94.7% freedom from device-related SAE at 30 days.

LEVEL OF EVIDENCE

Level 2b-prospective, multicenter, single-arm, first-in-human clinical study. Pre-specified endpoints were analyzed using descriptive statistics.

Drug-Eluting Bead Bronchial Arterial Chemoembolization With and Without Microwave Ablation for the Treatment of Advanced and Standard Treatment-Refractory/Ineligible Non-Small Cell Lung Cancer: A Comparative Study

Purpose

To compare the outcomes of drug-eluting bead bronchial arterial chemoembolization (DEB-BACE) with and without microwave ablation (MWA) for the treatment of advanced and standard treatment-refractory/ineligible non-small cell lung cancer (ASTRI-NSCLC).

Materials and Methods

A total of 77 ASTRI-NSCLC patients who received DEB-BACE combined with MWA (group A; n = 28) or DEB-BACE alone (group B; n = 49) were included. Clinical outcomes were compared between groups A and B. Kaplan–Meier methods were used to compare the median progression-free survival (PFS) or overall survival (OS) between the two groups. Univariate and multivariate Cox proportional hazards analyses were used to investigate the predictors of OS for ASTRI-NSCLC treated with DEB-BACE.

Results

No severe adverse event was found in both groups. Pneumothorax was the predominant MWA-related complication in group A, with an incidence rate of 32.1% (9/28). Meanwhile, no significant difference was found in DEB-BACE-related complications between groups A and B. The overall disease control rate (DCR) was 61.0% (47/77), with a significantly higher DCR in group A (85.7% vs. 46.9%, P = 0.002). The median PFS in groups A and B was 7.0 and 4.0 months, respectively, with a significant difference (P = 0.037). The median OS in groups A and B was both 8.0 months, with no significant difference (P = 0.318). The 6-month PFS and OS rates in groups A and B were 75.0% and 78.6%, 22.4% and 59.2%, respectively, while the 12-month PFS and OS rates in groups A and B were 17.9% and 28.6%, 14.3% and 22.4%, respectively. Of these, a significantly higher 6-month PFS rate was found in group A (75.0% vs. 22.4%; P < 0.001). The cycles of DEB-BACE/bronchial artery infusion chemotherapy [hazard ratio (HR): 0.363; 95% confidence interval (CI): 0.202–0.655; P = 0.001] and postoperative immunotherapy (HR: 0.219; 95% CI: 0.085–0.561; P = 0.002) were identified as the predictors of OS in ASTRI-NSCLC treated with DEB-BACE.

Conclusion

MWA sequentially combined with DEB-BACE was superior to DEB-BACE alone in the local control of ASTRI-NSCLC. Although the combination therapy reveals a trend of prolonging the OS, long-term prognosis warrants an investigation with a longer follow-up.