Evaluating the Safety and Effectiveness of Quick-Soluble Gelatin Sponge Particles for Genicular Artery Embolization for Chronic Knee Pain Associated with Osteoarthritis

Comparative Safety of 3 Temporary Embolic Agents in Transcatheter Arterial Embolization for Degenerative, Inflammatory, and Overuse Joint Disorders

PURPOSE

To evaluate the safety and degree of pain relief of 3 rapidly biodegraded embolic materials, including imipenem (IPM)/cilastatin sodium (CS), quick-soluble gelatin sponge particles (QS-GSPs), and resorbable microsphere (RMs), in transcatheter arterial embolization (TAE) for degenerative, inflammatory, and overuse joint disorders.

MATERIALS AND METHODS

Consecutive 431 patients, 527 joints with refractory overuse injuries, knee osteoarthritis, frozen shoulder, symptomatic rotator cuff tear, synovitis of the foot joints, and persistent pain after knee joint arthroplasty who underwent TAE between March 2020 and May 2023 were included in this retrospective study. IPM/CS, QS-GSPs, and RMs were used in 140 patients (176 TAEs), 136 patients (163 TAEs), and 155 patients (182 TAEs), respectively. Adverse events were monitored immediately after the procedure. Changes in pain numeric rating scale (NRS) score were evaluated at 1, 3, and 6 months after TAE.

RESULTS

No severe adverse events were observed. Increased pain at the site of embolization after the procedure lasting more than 7 days occurred in 7.1%, 22.1%, and 5.8% of patients with IPM/CS, QS-GSPs, and RMs, respectively, more commonly in the elbow joint. The NRS score improved from the baseline to 1, 3, and 6 months with IPM/CS (6.9 [SD ± 1.3] vs 4.4 [SD ± 2.2], 3.6 [SD ± 2.3], and 3.1 [SD ± 2.4], respectively; all P < .0001), QS-GSPs (6.4 [SD ± 1.5] vs 4.3 [SD ± 2.1], 3.6 [SD ± 2.2], and 3.0 [SD ± 2.1], respectively; all P < .0001), and RMs (7.0 [SD ± 1.3] vs 4.4 [SD ± 2.2], 3.2 [SD ± 2.1], and 2.3 [SD ± 1.8], respectively; all P < .0001).

CONCLUSIONS

IPM/CS, QS-GSPs, and RMs demonstrated acceptable safety profiles and effectively alleviated pain in TAE for degenerative, inflammatory, and overuse joint disorders.

Bioresorbable Gelatin Microspheres for Temporary Transarterial Embolization: Feasibility Study in Porcine Kidney Model

PURPOSE

To evaluate the in vivo characteristics, degradation profile, and feasibility of a bioresorbable gelatin microsphere (R-GM) for controlled, temporary embolization in a porcine kidney model.

MATERIALS AND METHODS

Six male farm pigs underwent transarterial embolization of the artery to the left kidney upper pole (LKUP) and to the right kidney upper pole (RKUP) using 100-300-µm-sized tris-acryl gelatin microsphere (T-GM) and R-GM, respectively. Follow-up angiography was performed in 2 h, 2 days, 1 week, 3 weeks, and 16 weeks to assess the presence of recanalization of the embolized arteries. Each pig was killed at each time point, and histopathologic analysis was performed to evaluate the presence of embolic agents, inflammatory reaction, and degree of tissue damage of the embolized renal segment.

RESULTS

On 2 h post-angiogram, LKUP was occluded, and RKUP was fully recanalized in all pigs. Parenchymal staining of the RKUP area was normalized at 2 h post-embolization and maintained until the 16-week follow-up. No R-GM or fragments were found in any specimens except for 2 days, but tris-acryl microspheres were observed in tissues with infarction with inflammatory changes until the 16-week follow-up. The levels of macrophages, giant cells, neovascularization, and fibrosis were higher in the LKUP compared to the RKUP at 1 week to 16 weeks (all, p < 0.05). The LKUP had a higher infarct area up to 97.17 ± 0.64% at 1 week compared to the RKUP, which had no infarction (0 ± 0%).

CONCLUSION

Temporary transarterial embolization using R-GM was feasible in vivo, achieving temporary occlusion followed by complete recanalization of the embolized vessel and minimal tissue damage.

LEVELS OF EVIDENCE

No levels of Evidence (Experimental study).

Safety and Efficacy of Genicular Artery Embolization for Knee Joint Osteoarthritis Associated Pain: A Systematic Review

PURPOSE

To systematically review the literature on the effectiveness, safety, and long-term outcomes of genicular artery embolization (GAE) for knee joint osteoarthritis (OA) associated pain.

MATERIALS AND METHODS

After registering the protocol with the PROSPERO database, a search was conducted from inception until July 31, 2023, in MEDLINE, Cochrane Central Register of Controlled Trials, and ScienceDirect databases to gather studies evaluating GAE's safety and efficacy in knee OA. A total of 4979 studies were identified and evaluated against the inclusion criteria. Data on study characteristics, success parameters, and adverse events were collected and synthesized.

RESULTS

Twenty-three studies, primarily single-center prospective studies with a total of 657 patients, were included. Most studies reported a 100% technical success rates, except one study reporting a rate of 84.2%. Clinical success rates, defined variably across studies, ranged from 30% to 100%, depending on the study's follow-up period and outcome measures. The most frequent adverse events included skin discoloration without an ulcer (15.6%, n = 98) and transient post-procedural knee pain (10.2%, n = 64). Most studies were rated as fair in terms of quality, but the lack of robust randomized controlled trials highlighted the need for further comparative studies to standardize outcome reporting.

CONCLUSION

GAE appears to be a promising option for knee OA pain, particularly for patients unresponsive to conservative treatments or ineligible for surgery. High-quality studies are needed to confirm long-term effectiveness and standardize outcome measures.Clinical ImpactThis study highlights the safety and efficacy of genicular artery embolization as a minimally invasive treatment for knee osteoarthritis, particularly in patients who are unresponsive to conservative treatments or unsuitable for surgery. By targeting neovascularization and reducing inflammation, genicular artery embolization provides pain relief and functional improvement. Clinicians can consider genicular artery embolization as an alternative to surgery for mild-to-moderate OA, offering a lower adverse event rate and faster recovery.

Lipiodol Versus Imipenem/Cilastatin in Genicular Artery Embolization: A Retrospective Study on Safety and Clinical Success

PURPOSE

This study aims to evaluate the safety and effectiveness of genicular artery embolization (GAE) using lipiodol in comparison to imipenem/cilastatin (IPM-CS).

MATERIALS AND METHODS

This retrospective study screened patients who underwent GAE between January 2022 and February 2023 for inclusion. Clinical outcomes were assessed at 1, 3, and 6 months post-procedure using the Visual Analog Scale (VAS) for pain and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for pain, stiffness, functional capacity, and total scores. Technical and clinical success rates, complications, and patient-reported outcomes were assessed.

RESULTS

A total of 42 patients were included in the study, with 13 patients treated with lipiodol and 29 with IPM-CS for GAE. Transient skin discoloration was noted in 23.1% of lipiodol patients and 31% of the IPM-CS group (p = 0.722). One patient (7.6%) in the lipiodol group developed knee edema and erythema due to drug-induced vasculitis (p = 0.309). Clinical success rates in the lipiodol group were 76.9% at 1 month, consistent at 3 months, and 69.2% at 6 months. For the IPM-CS group, success rates were 89.7, 86.2, and 75.9%, respectively, with no significant differences (p = 0.353, p = 0.657, p = 0.713). The median percentage change in WOMAC stiffness scores for the lipiodol group at 1, 3, and 6 months post-GAE were - 25%, - 16.7%, and - 16.7%, respectively, while the IPM-CS group showed decreases of - 40%, - 50%, and - 50%. Significant differences were found between the groups at all time points (p = 0.017, p = 0.009, and p = 0.002, respectively).

CONCLUSION

Lipiodol shows comparable clinical success to IPM-CS in GAE.

How Arterial Embolization Is Transforming Treatment of Oncologic and Degenerative Musculoskeletal Disease

BACKGROUND

Arterial embolization is a minimally invasive treatment that occludes blood vessels supplying pathological tissue. Developed to control bleeding without surgery, it has evolved over decades and is now applied in musculoskeletal oncology as a preoperative treatment, palliative care, or standalone therapy for select tumors. Recently, its use has expanded globally in treating chronic pain syndromes and osteoarthritis.

MATERIALS AND METHODS

We reviewed the literature on arterial embolization in various musculoskeletal conditions. The focus was on established oncologic indications for primary and metastatic bone or soft tissue tumors, and emerging evidence on degenerative diseases like osteoarthritis, inflammatory musculoskeletal pathology, and intractable pain. Emphasis was placed on leading studies regarding efficacy, complications, and recurrence rates.

DISCUSSION

Arterial embolization has progressed from bleeding control to a versatile therapeutic option in musculoskeletal medicine. It offers symptom relief, reduces tumor size, and improves quality of life. Applications include oncologic interventions and management of degenerative and inflammatory conditions. Despite its benefits, variations in complications and recurrence rates highlight the need for standardized protocols and further research.

CONCLUSIONS

Arterial embolization is a safe and effective minimally invasive tool in the multidisciplinary management of a wide range of musculoskeletal pathologies. Ongoing research is crucial to understand long-term efficacy, optimize protocols, and broaden its applications.

Knee pain improvement after genicular artery embolization for the management of knee osteoarthritis: an updated systematic review and meta-analysis of 21 studies

BACKGROUND

Knee osteoarthritis is a progressive inflammatory musculoskeletal disease with a prevalence of approximately 15-23% and limited treatment options. In recent years, transcatheter genicular artery embolization (GAE) has been proposed due to promising results concerning symptomatic knee pain relief and mobility.

OBJECTIVE

This systematic review and meta-analysis aimed to evaluate the aggregated data on the safety and efficacy of GAE for pain reduction in the treatment of knee osteoarthritis.

MATERIALS AND METHODS

A systematic search of the three major databases (MEDLINE, Embase, and CENTRAL) from inception to 27 February 2024 was conducted according to the PRISMA guidelines. Studies reporting pain reduction according to the Visual Analogue Scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)-Total, WOMAC-Pain, and Knee Injury and Osteoarthritis Outcome Score (KOOS)-Pain scales and adverse event rates were included. Meta-analysis was performed by estimating the mean differences and by fitting random-effect models.

RESULTS

Overall, 21 studies were included, comprising of 633 patients and 758 knees treated. The combined data analysis showed that patients who underwent GAE demonstrated mean declines in the VAS score of -38.5 points (95% confidence interval [CI]: -44.9, -32.0) at 1 month, -36.2 points (95% CI -43.0, -29.5) at 3 months, -40.3 points (95% CI: -49.0, -31.7) at 6 months, and -40.5 points (95% CI: -54.5, -26.6) at 12 months. Similarly, significant differences at all time points were also found for the WOMAC-Total, WOMAC-Pain, and KOOS-Pain scores. No difference between permanent and non-permanent embolic material was found in the subgroup analysis for all time points.

CONCLUSION

Genicular artery embolization is safe and effective for the treatment of painful knee osteoarthritis. This result was not affected by the type of embolic material used (permanent vs. non-permanent).

Minimally invasive interventional procedures for osteoarthritis and inflammatory arthritis: A systematic review and meta-analysis

OBJECTIVE

to summarize the evidence on the efficacy of minimally invasive interventional procedures such as radiofrequency ablation (RFA) and transcatheter arterial embolization (TAE) in patients with osteoarthritis or inflammatory arthritis.

METHODS

a literature search was conducted in PubMed and Web of Science databases. Both randomized controlled trials (RCTs) and non-randomized studies of interventions (NRSI) were included. The results were organized according to the treated anatomical site: knee, hip, foot and ankle, shoulder, hand and wrist, sacroiliac joints. Data about treatment efficacy were extracted. The main outcome was change in pain intensity using the 0-10 visual analog scale (VAS) from baseline to 1 month. Additional timepoints at 3, 6 and 12 months were assessed. Change in functional status was evaluated. Pooled estimates were calculated as the mean difference (MD) and 95 % confidence interval relative to baseline. The meta-analyses of RCTs and NRSI were conducted separately.

RESULTS

of the 4599 retrieved articles, 164 were included in the review and, considering all the established timepoints, 111 (38 RCTs and 73 NRSI) were selected for the meta-analysis. Only one article described patients with inflammatory arthritis. In the meta-analysis of RCTs, one month after the procedure, MD in VAS was -3.98 (-4.41 to -3.55; k = 21) for knee RFA, and -3.18 (-3.96 to -2.39; k = 8) for sacroiliac joints RFA. In the meta-analysis of NRSI, MD in VAS was -4.12 (-4.63 to -3.61; k = 23) for knee RFA, -3.84 (-4.77 to -2.92; k = 7) for knee TAE, -4.34 (-4.96 to -3.71; k = 2) for hip RFA, -3.83 (-4.52 to -3.15; k = 3) for shoulder RFA and -4.93 (-5.58 to -4.28; k = 14) for sacroiliac joints RFA. Significant decrease in pain intensity was found also at 3, 6 and 12 months. Additionally, functional status improved at all the assessed timepoints.

CONCLUSION

minimally invasive interventional procedures can improve pain and functional status of patients affected by OA or chronic sacroiliac pain of degenerative origin. Further research is warranted in the field of inflammatory rheumatic diseases.

Geniculate Artery Embolization for the Treatment of Mild to Moderate Knee Osteoarthritis Improves Pain and Function at Short-Term Follow-Up With Significant Procedural Heterogeneity Described Across the Literature: A Systematic Review

PURPOSE

To evaluate procedural heterogeneity, patient-reported outcomes (PROs), and complications following geniculate artery embolization (GAE) for knee osteoarthritis (OA).

METHODS

A literature search was performed using PubMed, Embase, and Scopus databases from inception to August 2023 according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Human clinical studies reporting PROs following GAE for treatment of knee OA were included, and a qualitative comparison across PROs, procedural descriptions, and complications was performed. Study quality was assessed using the Cochrane Collaboration's risk of bias tool and the Methodological Index for Non-Randomized Studies criteria. The primary outcome measures included changes in PROs at 12 months and variances in procedural methodology.

RESULTS

A total of 17 studies, consisting of 533 patients and 620 knees, were identified. The reported mean improvement at 12 months for visual analog scale for pain and Western Ontario and McMaster Universities Arthritis Index scores ranged from 10 to 59 and 35.3 to 47, respectively. At 12 months, median improvements were observed in Knee injury and Osteoarthritis Outcome Score subscales such as Pain (range, 8.3-19.5), Quality of Life (15.49-25.0), Sport (7.5-26.3), and Symptoms (1.8-25.0). Decreasing minimal clinically important difference (MCID) achievement was observed between the 3-month and 6-month follow-up points. Patients with advanced OA and degenerative findings on magnetic resonance imaging exhibited lower rates of MCID achievement. Transient adverse events occurred in up to 80% of patients. Limited evidence from serial magnetic resonance imaging assessments suggests that GAE improves levels of synovitis. Significant heterogeneity exists among the GAE methodology as 4 different definitions of technical success, 4 distinct embolization targets, and use of 5 embolization agents were noted.

CONCLUSIONS

GAE results in short-term improvements in pain and function with decreasing MCID achievement observed after 3 to 6 months. Patients with severe OA also demonstrate lower rates of MCID achievement. A high rate of transient complications is reported, including skin discoloration and access site hematomas. Significant protocol heterogeneity exists, which contributes to variable outcomes.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

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.

Genicular Artery Embolization: A New Tool for the Management of Refractory Osteoarthritis-Related Knee Pain

Osteoarthritis (OA) of the knee is a prevalent cause of chronic pain and disability, particularly affecting women. While traditionally attributed to chronic wear and tear, recent evidence highlights multifactorial pathogenesis involving low-grade inflammation and neoangiogenesis. Current therapeutic options include physical therapy, pharmacotherapy, and total knee arthroplasty (TKA). However, a subset of patients remain symptomatic despite conservative measures, necessitating the development of minimally invasive interventions. Genicular artery embolization (GAE) emerges as a promising option, targeting neovascularization and inflammatory processes in OA. This paper reviews the pathophysiological basis, patient selection criteria, procedural details, and outcomes of GAE. Notably, GAE demonstrates efficacy in relieving knee pain and improving function in patients refractory to conventional therapy. While further research is warranted to elucidate its long-term outcomes and compare it with existing modalities, GAE represents a novel approach in the management of symptomatic knee OA, potentially delaying or obviating the need for surgical intervention. Here, we synthesize the relevant literature, technical details of the procedure, and future perspectives. Moreover, the success of GAE prompts the exploration of transarterial embolization in other musculoskeletal conditions, underscoring the evolving role of interventional radiology in personalized pain management strategies.

Genicular Artery Embolization: Embolic Material and Imaging Review

Osteoarthritis (OA) of the knee is a degenerative condition impacting numerous individuals globally. Genicular artery embolization (GAE) has emerged as an effective minimally invasive therapy for managing medically refractory OA-related pain in patients who are not eligible for surgery. This intervention works by disrupting the inflammatory and neoangiogenic pathways that contribute to pain. The efficacy of GAE has been demonstrated in various clinical trials, yielding promising results. This review aims to explore recent advancements in the embolic materials used during GAE, examining their properties and potential benefits. Additionally, it will describe the use of pre-, intra-, and postprocedural imaging-particularly magnetic resonance imaging and other modalities-to optimize GAE outcomes.

Preliminary report on embolization with quick-soluble gelatin sponge particles for angiographically negative acute gastrointestinal bleeding

Prophylactic embolization is usually performed using gelatin sponge particles, which are absorbed within several weeks, for managing angiographically negative gastrointestinal bleeding. This study aimed to evaluate the safety and effectiveness of transcatheter arterial embolization (TAE) with quick-soluble gelatin sponge particles (QS-GSP) that dissolve in less than 4 h for treating angiographically negative gastrointestinal bleeding. We included ten patients (M:F = 7:3; mean age, 64.3 years) who underwent prophylactic TAE with QS-GSP for angiographically negative acute gastrointestinal bleeding between 2021 and 2023. The technical success rate of TAE, clinical outcomes focusing on rebleeding, and procedure-related complications were evaluated. The embolized arteries were the gastroduodenal (n = 3), jejunal (n = 4), and ileal (n = 3) arteries. QS-GSP (150-350 µm or 350-560 µm) were used alone (n = 8) or in combination with a coil (n = 1). A 100% technical success rate was accomplished. In 1 patient (10%), rebleeding occurred 2 days after prophylactic TAE of the gastroduodenal artery, and this was managed by repeat TAE. There were no procedure-related complications. The use of QS-GSP for prophylactic TAE appears to be safe and effective for controlling bleeding among patients with angiographically negative gastrointestinal bleeding. There were no cases of related ischemic complications of the embolized bowels likely attributable to recanalization of the affected arteries following biodegradation of QS-GSP.