Imipenem/cilastatin sodium (IPM/CS) as an embolic agent for transcatheter arterial embolisation: a preliminary clinical study of gastrointestinal bleeding from neoplasms

Transarterial Embolization for Adhesive Capsulitis of the Shoulder: Midterm Outcomes on Function and Pain Relief

PURPOSE

To determine the safety and potential effectiveness of transarterial embolization for adhesive capsulitis of the shoulder.

MATERIALS AND METHODS

This prospective study analyzed consecutive adult patients with adhesive capsulitis referred for embolization between January 2018 and May 2023 after a poor response to treatment (symptoms and limitation of motion in ≥2 axes; ≤120° flexion, ≤50° external rotation and/or internal rotation with the shoulder abducted 90°) persisting for >3 months after having completed ≥6 weeks of analgesics and physical therapy. Different types of pain and mobility were measured before embolization and 1, 3, and 6 months after embolization. Overall upper limb function (Quick Disabilities of Arm, Shoulder, and Hand) and patient satisfaction were measured before and 6 months after embolization. Long-term follow-up comprised telephone interviews and clinical history reviews.

RESULTS

A total of 20 patients (12 [60%] women; median age, 50.7; interquartile ranges [IQR], 45‒55 years) were included; 6 (30%) had diabetes and 15 (75%) were off work. Median duration of symptoms before embolization was 39.4 weeks (IQR, 28‒49 weeks), and median duration of rehabilitation therapy was 12.8 weeks (IQR, 8‒16 weeks). Six months after embolization, significant improvements were observed in nocturnal pain (P = .003), pain on moving (P = .001), external rotation (P < .001), internal rotation (P < .001), active flexion (P < .001), passive flexion (P = .03), active abduction (P < .001), passive abduction (P < .001), and overall function (P < .001). Despite objective improvements, patient satisfaction was nearly unchanged. Only 1 patient experienced a mild adverse event.

CONCLUSION

Transarterial embolization is safe and potentially effective in treating adhesive capsulitis of the shoulder refractory to conventional treatment. Clinical improvements were maintained in the mid to long term.

Short-term clinical outcomes of transarterial embolization for symptomatic hand osteoarthritis refractory to conservative treatment

PURPOSE

The present study aims to assess the short-term clinical outcomes and safety of transarterial embolization (TAE) for symptomatic hand osteoarthritis (OA) refractory to conservative treatment.

METHODS

The present retrospective cohort pilot study included nine patients who underwent TAE for symptomatic OA-associated hand pain in a single tertiary center between November 2022 and January 2023. The baseline and post-procedural OA-associated hand pain and function were assessed using the visual analog scale (VAS) and the Australian Canadian Hand Osteoarthritis Index (AUSCAN). The use of conservative treatment and pain medications was also recorded. Post-procedural adverse events were evaluated according to the Society of Interventional Radiology classification.

RESULTS

Compared with the baseline, the overall VAS scores were significantly decreased at 1-week, 1-month, 3-months, and 6-months after TAE (76 ± 15 mm versus 34 ± 18 mm, P < 0.001; 32 ± 11 mm, P < 0.001; 21 ± 15 mm, P < 0.001; 18 ± 19 mm, P = 0.002). Similarly, improvement in the mean total AUSCAN scores (22.0 ± 10.0 versus 13.2 ± 6.6, P = 0.007; 14.11 ± 7.3, P = 0.004; 9.8 ± 6.8, P = 0.004; 9.3 ± 7.4, P = 0.011) were documented. The use of other conservative treatment methods also gradually decreased. There were no severe adverse events reported during the follow-up period.

CONCLUSION

TAE is a feasible and safe treatment method for symptomatic hand OA refractory to conservative treatment. This minimally invasive procedure effectively relieves debilitating OA-associated joint pain and restores hand function with a durable treatment effect.

Musculoskeletal Embolotherapy

Painful articular musculoskeletal (MSK) conditions are common, debilitating and sometimes difficult to treat. Transcatheter embolisation may offer an alternative way to manage the pain associated with these conditions, but the field is still in its infancy. To date, the most commonly studied indication is knee osteoarthritis, but the technique has been trailed in multiple other tissue beds, including for adhesive capsulitis and tendinopathies. Whilst early results appear promising, the existing studies are mostly open-labelled and non-randomised; there is a need for high-quality evidence to robustly assess the procedures efficacy. In this review, we set out to evaluate the current evidence underlying the pathophysiology and mechanism of action of embolisation; discuss the technical aspects of the procedure including embolic selection, and appraise the published clinical outcomes and adverse effects. Finally, we discuss the future directions and research priorities in this rapidly developing field.

Transcatheter arterial embolisation for the relief of shoulder and elbow chronic joint pain refractory to conventional treatment: Systematic review

Angiogenesis and accompanying nerve fibres might cause unsettling joint pain. Studies have suggested that transcatheter arterial embolisation (TAE) of these abnormal neovessels could relieve pain and symptoms in patients with upper limb joint pain refractory to conventional treatment. This study aims to investigate the efficacy and safety of TAE in treating chronic pain of shoulder and elbow joints that have been resistant to other treatments. Using six databases, a systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The primary outcome involved changes in the visual analogue scale (VAS) after TAE; while secondary outcomes involved comparing other parameters where relevant. Average VAS decreased from baseline, then at 1 day, 1 week, 1 month, 3 months, 4 months, 6 months, 1 year, 2 years and 44 months (7.5 at baseline vs. 4.7, 4.3, 3.4, 2.1, 2.5, 1.2, 0.7, 1.1 and 0.1, respectively). Average Quick-DASH scores decreased from baseline, then at 1, 3 and 6 months (61.3 at baseline vs. 30.6, 19.3 and 6.9, respectively). Minor adverse events were reported in 27/143 (18.9%) patients, where they resolved spontaneously or with oral analgesia. TAE is a possible treatment option for refractory shoulder and elbow joint pain; however, randomised controlled trials are still required.

Successful treatment of multiple microbleeds in a large area of the small bowel by transcatheter arterial embolization using imipenem/cilastatin as embolization material

A 44-year-old man with chronic idiopathic pseudo-intestinal obstruction and lumbar disc herniation presented with orthostatic dizziness, black vomiting, and stools. He was suspected to have an ulcer caused by nonsteroidal anti-inflammatory drugs and treated conservatively but continued to have transfusion-dependent anemia. Trans-arterial contrast-enhanced computed tomography showed multiple microbleeds in the small intestine. We diffusely embolized 7 small intestine branches of the superior mesenteric artery using imipenem/cilastatin on 2 separate occasions. This stopped the bleeding, and the patient progressed well without ischemic complications and was discharged on the 25th postoperative day. Transcatheter arterial embolization with imipenem/cilastatin may be a viable treatment option for patients with multiple small bowel bleeds in a large area of the small intestine that are unresponsive to conservative treatment or endoscopic methods.

Transcatheter embolisation in chronic musculoskeletal disorders

Chronic musculoskeletal conditions affect millions of patients worldwide resulting in disability, reduced quality of life, and have a profound economic impact on the individual and society. Current treatment strategies fail patients who have not responded to conservative management but are not surgical candidates. Over the last decade, transcatheter embolisation has emerged as a potential treatment for these difficult to treat patients. By exploiting pathological neovascularisation within conditions such as knee osteoarthritis, adhesive capsulitis, and tendinopathy, embolisation has been used to improve patients' pain and function. This review explores the rationale for musculoskeletal transcatheter embolisation, illustrating the technique, and latest evidence for the most common procedures.

Genicular Artery Embolization for Knee Osteoarthritis: A Comprehensive Review

» Genicular artery embolization (GAE) is a promising treatment option for patients with knee osteoarthritis who are unresponsive to nonsurgical treatments and not yet candidates for surgery.» Current evidence supports the effectiveness of GAE in reducing pain and synovitis, with few reported major adverse events.» The cost-effectiveness and long-term results of GAE compared with other treatment options require further investigation.» Limitations of existing studies include small sample sizes, single-center trials, and lack of comparison between embolic agents and other treatments.» Future research should focus on larger, multicenter trials with longer follow-up periods and head-to-head comparisons with alternative treatment modalities to establish the role of GAE in the management of knee osteoarthritis.

Transcatheter arterial embolization for acute lower gastrointestinal bleeding using imipenem/cilastatin: a single-center retrospective study

BACKGROUND

Transcatheter arterial embolization (TAE) is a standard treatment for acute lower gastrointestinal bleeding (LGIB) in situations where endoscopic approaches are impossible or ineffective. Various embolic materials, such as metallic coils and N-butyl cyanoacrylate, are used. This study aimed to evaluate the clinical outcomes of an imipenem/cilastatin (IPM/CS) mixture as an embolic agent in TAE for acute LGIB.

RESULTS

Twelve patients (mean age, 67 years) with LGIB treated with TAE using IPM/CS were retrospectively evaluated between February 2014 and September 2022. All patients showed evidence of extravasation on computed tomography and 50% (6/12) also showed evidence on angiography. The technical success rate for TAE in this study was 100%, including in patients who showed active extravasation on angiography. The clinical success rate was 83.3% (10/12), with two patients experiencing rebleeding within 24 h after the procedure. No ischemic complications were observed, and no bleeding episodes or other complications were reported during the follow-up period.

CONCLUSIONS

This study revealed that using IPM/CS as an embolic agent in TAE for acute LGIB may be safe and effective, even in cases of active bleeding.

Embolic Decision Making in Musculoskeletal Embolization

In his pioneering work, Okuno and colleagues demonstrated the benefit of musculoskeletal (MSK) embolization, using imipenem as an embolic agent, in various diseases such as knee osteoarthritis (KOA), adhesive capsulitis (AC), tennis elbow and other sports injuries. As imipenem is a last-resort, broad spectrum antibiotic, its use is often not feasible depending on countries and their drug regulation. Since then, several other studies have used other material products such as microparticles or liquid embolics. In addition, several products in development or that are used in other indications may prove useful after full clinical evaluation of safety and efficacy. In this article we will develop our recommendations, through an analysis of recent publications on MSK embolization.

At the Edge of Orthopaedics: Initial Experience with Transarterial Periarticular Embolization for Knee Osteoarthritis in a Romanian Population

Background: Transarterial embolization (TAE) of genicular artery branches is a relatively new technique that has emerged as a promising method for delaying invasive knee surgery in patients suffering from degenerative knee osteoarthritis (OA). In mild to moderate OA, invasive major surgery can be safely postponed, and patients with major risk factors now have an alternative. Our aim was to examine the impact of TAE on clinical outcomes in individuals with degenerative knee OA over a 12-month period. Methods: A case series of 17 patients diagnosed with knee OA and treated with TAE was included in the study. Every patient was clinically evaluated at different timeframes according to the Western Ontario and McMaster Universities’ arthritis index, knee injury, and osteoarthritis outcome scores, and the 36-item short-form survey (WOMAC, KOOS, and SF-36). Results: At the first follow-up (1 month), KOOS and WOMAC improved from 46.6 ± 13.2 (range 27.3–78.2) to 56.5 ± 13.9 (range 32.3–78.4; p = 0.023) and 49.5 ± 13.2 (range 29.3–82.3) to 59.8 ± 12.6 (range 39.3–83.5, p = 0.018), respectively. Physical SF-36 improved significantly from 42.1 ± 7.75 (range 30.3–57.3) to 50.5 ± 9.9 (range 35.6–67.9; p = 0.032). No significant changes in scores were observed at three, six, or twelve months after TAE. Conclusions: TAE provided early pain reduction and considerable improvement in quality of life without complications for a consecutive sample of Romanian patients with mild to severe knee OA.

Transcatheter arterial embolization using imipenem/cilastatin sodium and microspheres for traumatic pseudoaneurysm: A case report

For transcatheter arterial embolization (TAE) of pseudoaneurysms, when the culprit artery is too small or tortuous to be selected with a microcatheter, n-butyl-2-cyanoacrylate (NBCA) may be used as embolic material. Nevertheless, NBCA can cause inadvertent embolization and ischemic complications because liquid adhesives cannot be controlled precisely. In such cases, imipenem/cilastatin sodium (IPM/CS) could be used as an alternative to NBCA for TAE. However, TAE using IPM/CS for traumatic pseudoaneurysms has not been reported previously. Therefore, the possibility of using IPM/CS to embolize refractory traumatic pseudoaneurysms with small culprit arteries remains unknown. A previously healthy 51-year-old man sustained multiple traumatic injuries, including an open pelvic fracture. An emergency TAE for the pelvic fracture, massive blood transfusion, and emergency colostomy and cystostomy were performed on admission day, following which the patient was hemodynamically stable. However, he had repeated episodes of hematochezia due to pelvic pseudoaneurysm on days 18, 53, 60, and 70 after admission despite several TAE attempts using gelatin sponge, coils, and NBCA. During recurrence on day 70, we performed TAE using IPM/CS and microspheres, following which the pseudoaneurysm resolved without rebleeding or obvious ischemic complications. IPM/CS and microspheres could embolize, without rebleeding, the refractory pseudoaneurysm in small and tortuous culprit arteries that could not be embolized with NBCA. For embolization of traumatic pseudoaneurysms with severe tissue damage and small culprit arteries, NBCA might not be able to reach the bleeding point. In such cases, TAE using IPM/CS and microspheres could be a safe and effective procedure.

Feasibility of Neovessel Embolization in a Large Animal Model of Tendinopathy: Safety and Efficacy of Various Embolization Agents

Targeting neovessels in chronic tendinopathies has emerged as a new therapeutic approach and several embolization agents have been reported. The aim of this study was to investigate the feasibility of embolization with different agents in a porcine model of patellar tendinopathy and evaluate their safety and efficacy. Eight 3-month-old male piglets underwent percutaneous injection of collagenase type I to induce patellar tendinopathies (n = 16 tendons). They were divided into four groups (2 piglets, 4 tendons/group): the control group, 50–100 µm microspheres group, 100–300 µm microspheres group, and the Imipenem/Cilastatin (IMP/CS) group. Angiography and embolization were performed for each patellar tendon on day 7 (D7). The neovessels were evaluated visually with an angiography on day 14. The pathological analysis assessed the efficacy (Bonar score, number of neovessels/mm²) and safety (off-target persistent cutaneous ischemic modifications and presence of off-target embolization agents). The technical success was 92%, with a failed embolization for one tendon due to an arterial dissection. Neoangiogenesis was significantly less important in the embolized groups compared to the control group angiographies (p = 0.04) but not with respect to histology (Bonar score p = 0.15, neovessels p = 0.07). Off-target cutaneous embolization was more frequently depicted in the histology of the 50–100 µm microspheres group (p = 0.02). Embolization of this animal model with induced patellar tendinopathy was technically feasible with different agents and allowed assessing the safety and efficacy of neovessel destruction. Particles smaller than 100 µm seemed to be associated with more complications.

6-Month Follow-up of Lateral Femoral Circumflex Artery Embolization to Control Pain Related to Hip Osteoarthritis and Greater Trochanteric Pain Syndrome

Purpose

To present the preliminary results of a cohort of 13 patients with hip osteoarthritis (OA) and great trochanteric pain syndrome (GTPS) refractory to conservative management or physical therapy and no indication for surgery treated with embolization of the lateral femoral circumflex artery.

Material and Methods

This is a single-center prospective cohort from July 2019 to September 2020. Visual analogue scale (VAS) and Western Ontario and MacMaster Universities (WOMAC) were used to compare the symptoms before and after 6-month follow-up. Technical success was considered when at least one artery responsible for the hyperemic synovium was embolized. Complications and adverse events were noted.

Results

In total, 13 patients were included; mean age was 62.4 (± 11.0) years. 10 (76.9%) patients were treated for GTPS and 3 (23.1%) for hip OA. Nine patients were treated with imipenem/cilastatin (I/C) alone. Microsphere 100–300 μm and I/C were combined in 4 patients. The WOMAC Index had a statistically significant decrease in the total from 77 to 27 points (p = 0.001). Pain, rigidity and physical activity have also significantly reduced (19 to 5, p = 0.001; 6 to 2, p = 0.002 and 53 to 22, p = 0.001, respectively). VAS score had a significant decrease (10 to 2, p = 0.002). Two patients present posterior tight numbness, spontaneously improved within 30 days.

Conclusion

In this cohort, lateral femoral circumflex artery embolization was a safe and effective treatment for patients with hip pain due to OA and GTPS.

Transcatheter arterial embolization of abnormal neovessels in a swine model of knee arthritis

BACKGROUND

In recent years, transcatheter arterial embolization (TAE) using imipenem/cilastatin (IPM/CS) has attracted attention as a treatment for relieving osteoarthritis (OA) pain. However, IPM/CS is not approved by Japanese medical insurance for use as an embolic material. Therefore, it is necessary to develop new embolic materials for TAE to relieve OA pain. The purpose of this study was to develop a swine model of knee arthritis and embolize abnormal neovessels (ANs) using two different embolic materials. We compared the embolic effects and tissue damage in knees.

METHODS

Knee arthritis was induced by intra-articular injection of papain into 12 knees in six female swine. The swine were divided into two groups of three swine each (six knees per group) for embolization of ANs in the knees with either IPM/CS or soluble gelatin sponge particles (SGSs). Three days after embolization, we compared the embolic effects using angiography and the tissue damage histopathologically.

RESULTS

ANs were observed in all 12 knees at 42 days after papain injection. The ANs disappeared and the patent arteries were recanalized 3 days after TAE in all 12 knees. Histopathological evaluation revealed synovitis changes, such as synovial thickening and inflammatory cell infiltration, in all 12 knees. There was no evidence of skin or muscle necrosis in either group. The appearance of ANs, recanalization of the parent arteries, and histopathological outcomes were not significantly different between the two groups.

CONCLUSION

SGSs were as safe as IPM/CS for TAE of ANs in this swine model of knee arthritis.

Safety and Efficacy of Embolization with Microspheres in Chronic Refractory Inflammatory Shoulder Pain: A Pilot Monocentric Study on 15 Patients

Purpose: Musculoskeletal (MSK) embolization is emerging in tendinopathy treatment. The objective of this study was to assess the efficacy and safety of MSK embolization with microspheres in the treatment of chronic shoulder pain. Patients and methods: This retrospective monocentric study included patients with chronic shoulder pain resistant to 6 months or more of conventional therapies who were treated with MSK embolization between 2017 and 2021. Embolization was performed using calibrated 100–250 µm microspheres. Clinical success was defined as pain reduction, i.e., a decrease in the visual analogue scale (VAS) pain score of ≥50% at 3 months after MSK embolization as compared to baseline. Adverse events were collected. Results: Fifteen patients (11 women, 4 men) were included, with a median age of 50.3 years (IQR: 46.7–54.5). The median duration of symptoms was 26.6 months (20.6–39.8). The median VAS pain scores were 7.0 (7.0–8.0) at baseline, 6.0 (3.5–7.0) at 1 month, 5.0 (4.5–6.5) and 5.0 (3.0–7.4) at 3 months and 6 months (p = 0.002). Three patients (20%) reported clinical success at 3 months. Three patients experienced minor complications after embolization (paresthesia, n = 2; transient osteo-medullary edema, n = 1) and two patients had moderate complications (transient skin ischemia). Conclusion: MSK embolization with microspheres for treatment of refractory chronic shoulder pain showed moderate results in terms of clinical success and safety.

GAUCHO - Trial Genicular Artery Embolization Using Imipenem/Cilastatin vs. Microsphere for Knee Osteoarthritis: A Randomized Controlled Trial

Genicular artery embolization (GAE) has emerged as a treatment option to improve quality of life in patients suffering from moderate-to-severe pain refractory to conservative treatment of knee osteoarthritis, with encouraging results. This paper describes the study protocol of a single-center, double-blind, randomized controlled trial designed to evaluate and compare the safety and efficacy of GAE using imipenem/cilastatin vs. microspheres for the treatment of moderate-to-severe pain associated with knee osteoarthritis. We hypothesized that there will be no difference in safety and efficacy outcomes. The study received ethics approval of the institutional review board with number 4.364.391 / CAAE: 37590820.3.0000.5342 and is registered onto the Registro Brasileiro de Ensaios Clinicos (ReBEC), with number RBR-2h5rwgb. Technical success was defined as embolization of at least 1 feeding artery supplying the hyperemic synovium of the knee joint. Primary outcome: clinical success was defined as improvement in symptoms, 50% reduction in Western Ontario and McMaster Universities Osteoarthritis Index pain scores or an increase of at least 10 points in the Knee Injury and Osteoarthritis Outcome Score from baseline to 3 months of follow-up. Secondary outcome: radiological success was defined as significant improvement in the Whole-Organ Magnetic Resonance Imaging Score for knee synovitis considering the embolized areas at 12 months of follow-up after GAE and a reduction in the analgesia or other conservative therapies for knee pain used by the patient at 3 and 12 months of follow-up. Clinical assessments will be performed before GAE, during GAE and at hospital discharge (for Visual Analog Scale of pain), and at 30 days, 3 months, and 12 months after GAE.

Small bowel bleeding treated successfully with transcatheter arterial embolization with imipenem/cilastatin

Background

Small bowel bleeding is an uncommon cause of lower gastrointestinal bleeding, which may require different management.

Case Presentation

A 37‐year‐old man presenting with hematochezia was promptly diagnosed with small bowel bleeding by computed tomography angiography. Transcatheter arterial embolization was carried out because the patient's hemodynamic status deteriorated. Hemostasis was achieved by embolization with imipenem/cilastatin, although superselective embolization failed. Capsule endoscopy revealed multiple ulcers and erosions. Drug‐induced small bowel injury was suspected to be the cause of small bowel bleeding.

Conclusion

Computed tomography angiography can facilitate the management of lower gastrointestinal bleeding. Considering transcatheter arterial embolization and choosing an optimal embolic agent depending on the situation are important in the management of hemodynamically unstable patients.

Geniculate Artery Embolization: Role in Knee Hemarthrosis and Osteoarthritis

Roughly 37% of Americans 60 years of age and older experience chronic pain due to osteoarthritis (OA) of the knee. After conservative treatment (pharmacologic, physical therapy, and joint injections) fails, patients often require total knee arthroplasty to alleviate pain and regain knee function. Given the high economic burden of surgery paired with its invasive nature, many patients with this degenerative joint disease seek alternative treatment. Moreover, many patients with severe knee OA who also have comorbidities that preclude surgery-most often morbid obesity-are left without options. Geniculate artery embolization (GAE) is a minimally invasive intra-arterial intervention that was originally developed for the treatment of knee hemarthrosis that has recently been adapted for symptomatic knee OA. Through selective embolization of geniculate branches corresponding to the site of knee pain, GAE inhibits the neovascularity that contributes to the catabolic and inflammatory drive of OA. Preliminary trials over the past decade have demonstrated promising clinical results, including decreased pain and improved function and quality of life after treatment. Given such success, GAE provides another minimally invasive treatment option for knee OA to patients who feel reluctant to undergo or are ineligible for surgery. The authors review the radiographic manifestations and current standard of treatment of OA and hemarthrosis of the knee. Procedural technique, embolic selection, and clinical evidence for GAE in the treatment of OA and hemarthrosis of the knee are also explored. The online slide presentation from the RSNA Annual Meeting is available for this article. ^©RSNA, 2021.

Temperature-responsive biodegradable injectable polymers with tissue adhesive properties

Injectable polymers (IPs) exhibiting in situ hydrogel formation have attracted attention as vascular embolization and postoperative adhesion prevention materials. While utilizing hydrogels for such purposes, it is essential to ensure that they have appropriate and controllable tissue adhesion property, as it is crucial for them to not detach from their deposited location in the blood vessel or abdominal cavity. Additionally, it is important to maintain gel state in vivo for the desired period at such locations, where large amounts of body fluid exist. We had previously reported on a biodegradable IP system exhibiting temperature-responsive gelation and subsequent covalent cross-link formation. We had utilized triblock copolymers of aliphatic polyester and poly(ethylene glycol) (tri-PCGs) and its derivative containing acrylate group at the termini (tri-PCG-Acryl), exhibiting a longer and more controllable duration time of the gel state. In this study, the introduction of aldehyde groups by the addition of aldehyde-modified Pluronic (PL-CHO) was performed for conferring controllable and appropriate tissue adhesive properties on these IP systems. The IP systems containing PL-CHO, which were not covalently incorporated into the hydrogel network, exhibited tissue adhesive properties through Schiff base formation. The adhesion strength could be controlled by the amount of PL-CHO added. The IP system showed good vascular embolization performance and pressure resistance in the blood vessels. The IP hydrogel remained at the administration site in the abdominal space for 2 days and displayed effective adhesion prevention performance. STATEMENT OF SIGNIFICANCE: Injectable polymers (IPs), which exhibit in situ hydrogel formation, are expected to be utilized as vascular embolization and postoperative adhesion prevention materials. The tissue adhesion properties of hydrogels are important for such applications. We succeeded in conferring tissue adhesion properties onto a previously reported IP system by mixing it with Pluronic modified with aldehyde groups (PL-CHO). The aldehyde groups allowed for the formation of Schiff bases at the tissue surfaces. The tissue adhesion property could be conveniently controlled by altering the amount of PL-CHO. We revealed that the in vitro embolization properties of IPs in blood vessels could be substantially improved by mixing with PL-CHO. The IP system containing PL-CHO also exhibited good in vivo performance for postoperative adhesion prevention.

A Rat Model of Frozen Shoulder Demonstrating the Effect of Transcatheter Arterial Embolization on Angiography, Histopathology, and Physical Activity

PURPOSE

To assess the angiographic findings and the effects of transcatheter arterial embolization on physical activity and histopathology using a frozen shoulder rat model.

MATERIALS AND METHODS

First, the angiographic and histopathologic findings of rats in which the shoulder was immobilized with molding plaster for 6 weeks (n = 4) were compared to control rats with normal non-immobilized shoulders (n = 4). Next, a total of 16 frozen shoulder rats were divided into 2 groups. In the transcatheter arterial embolization group (n = 8), imipenem/cilastatin was injected into the left thoracoacromial artery. The changes of physical activity before and after procedures were evaluated and compared with a saline-injected control group (n = 8). Histopathologic findings were also compared between the 2 groups.

RESULTS

Angiography revealed abnormal shoulder staining in all of the rats with a frozen shoulder. On histopathology, the numbers of microvessels and mononuclear inflammatory cells in the synovial membrane of the joint capsule were significantly higher compared with the control rats (both P = .03). In the transcatheter arterial embolization group, the running distance and speed were improved (P = .03 and P = .01, respectively), whereas there were no significant differences in the control group. The number of microvessels and mononuclear inflammatory cells in the transcatheter arterial embolization group were significantly lower than the control group (P = .002 and P = .001, respectively).

CONCLUSIONS

The rat frozen shoulder model revealed the development of neovascularization. Transcatheter arterial embolization decreased the number of blood vessels and inflammatory changes in the frozen shoulder and increased the moving distance and speed of the rats.

Clinical Outcomes of Transcatheter Arterial Embolization for Secondary Stiff Shoulder

PURPOSE

To assess the clinical outcomes of transcatheter arterial embolization (TAE) for secondary stiff shoulder (SSS).

MATERIALS AND METHODS

This is a retrospective analysis of prospectively collected data performed between January 2017 and December 2019. This study comprised 25 patients (20 women and 5 men; median age, 49 years; range 27-59) with SSS resistant to conservative management during at least 3 months. The median time of stiffness was 12 months. The etiology of SSS was postoperative in 14 patients (56%) and posttraumatic in the remaining 11 patients (44%). Periods of immobilization in all patients were associated. TAE was performed, and technical aspects, adverse events, changes for pain, and physical examination before and 6 months after TAE were assessed.

RESULTS

Abnormal vessels were observed in 20 of 25 (80%) of the procedures. Transitory cutaneous erythema was noted in 4 patients treated after TAE. Significant differences were observed in the median pain visual analog scale reduction between before and 6 months after TAE (8 vs 2, P < .001). Shoulder mobility significantly improved in both flexion and abduction degrees between before and at 6 months after TAE in (70° vs 150°; P < .001). No symptoms of recurrence appeared.

CONCLUSIONS

TAE can result in pain reduction and mobility improvement in patients with SSS refractory to conservative therapy.

Mid-Term Results of Transcatheter Arterial Embolization for Adhesive Capsulitis Resistant to Conservative Treatment

PURPOSE

To evaluate the mid-term clinical outcomes of transcatheter arterial embolization (TAE) for adhesive capsulitis (AC) resistant to medical treatments.

MATERIALS AND METHODS

This is a prospective analysis performed between February 2016 and February 2020. Inclusion criteria for TAE were shoulder pain, restriction of movement and no response to conservative treatment for at least 3 months. Demographic variables, risk factors, technical aspects, adverse events, changes by visual analogue scale (VAS) for pain and physical examination before and after TAE were assessed.

RESULTS

This study included 40 patients with AC (35 women and 5 men; mean age 50 ± 9 years old). Abnormal vessels were observed in 31/40 (77.5%) procedures. As embolic agent, imipenem/cilastatin was used. The mean follow-up was 21.2 ± 10.5 months. Significant differences were obtained in terms of pain reduction before and 6 months after TAE with the median visual analogue scale (VAS) of 8 vs. 0.5, P = 0.0001. Substantial differences were found regarding mobility in flexion and abduction before and 6 months after embolization, respectively (79.5° ± 18.5° vs. 133° ± 24.5°, P = 0.0001; 72.4° ± 18.8° vs. 129.7° ± 27.9°, P = 0.0001). No complications occurred. Complete recovery was obtained in 37/40 (92.5%) patients and partial recovery in 2/40 (5%). No clinical recurrence appeared.

CONCLUSIONS

Clinical results of transcatheter arterial embolization with imipenem/cilastatin are effective and stable in the mid-term follow-up for patients presenting with AC resistant to conservative treatments.

Genicular Artery Embolization for Osteoarthritis Related Knee Pain: A Systematic Review and Qualitative Analysis of Clinical Outcomes

Objective To systematically review the published literature on genicular artery embolization (GAE) for osteoarthritis (OA) related knee pain. Materials and Methods Using three databases, a systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Outcome measures included the Visual Analog Scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Results Three single-arm studies were included from an initial search yielding 305 results. One hundred and eighty-six knees in 133 patients with either mild-to-moderate (174/186, 94%) or severe (12/186, 6%) OA underwent embolization with either imipenem/cilastatin sodium (159/186, 85%) or embozene (27/186, 15%). Technical success was 100%. Average VAS improved from baseline at 1 day, 1 week, 1 month, 3 months, 4 months, 6 months, 1 year and 2 years (66.5 at baseline vs 33.5, 32.7, 33.8, 28.9, 29.0, 22.3, 14.8 and 14.0, respectively). Average WOMAC scores improved from baseline at 1, 3, 4, 6, 12 and 24 months (45.7 at baseline vs 24.0, 31.0, 14.8, 14.6, 8.2 and 6.2). Severe OA in 12 cases showed initially improved VAS, but was not sustained. Minor adverse events such as erythema in the region of embolization (21/186, 11%), puncture-site hematoma (18/186, 10%), paresthesia (2/186, 1%) and fever (1/186, 0.5%) were reported. Conclusion Limited single-arm studies report GAE is promising for treating OA-related pain. Most treatments performed for mild-to-moderate OA demonstrated durable clinical responses from 6 months to 4 years. Limited data for severe OA suggest a non-durable response. Future studies should be standardized to facilitate comparison and control for placebo effect.

Effects of Transcatheter Arterial Microembolization on Persistent Trapezius Myalgia Refractory to Conservative Treatment

PURPOSE

To evaluate the safety and efficacy of transcatheter arterial microembolization for patients with trapezius myalgia.

MATERIALS AND METHODS

We retrospectively evaluated the prospectively collected data of patients with trapezius myalgia for > 6 months who were refractory to conservative treatment and were treated by transcatheter arterial microembolization between October 2017 and January 2019. Transcatheter arterial microembolization was performed using imipenem/cilastatin on the vessels of the transverse cervical artery, suprascapular artery, and circumflex scapular artery according to the region of pain.

RESULTS

Forty-two patients were treated by transcatheter arterial microembolization and followed up for 6 months. No major adverse events occurred related to the procedures. The brief pain inventory worst pain scores significantly improved at 1, 2, 3, and 6 months after transcatheter arterial microembolization (8.6 ± 1.3 (before procedure) vs. 5.1 ± 2.9, 4.4 ± 2.9, 4.1 ± 2.8, and 3.9 ± 2.9, respectively, P < 0.001). The brief pain inventory pain interference scores, including general activity, mood, walking ability, normal work, relations with others, sleep, and enjoyment of life, also significantly decreased at 1, 2, 3, and 6 months after transcatheter arterial microembolization compared to those at baseline (all P < 0.01). The clinical success rate at 6 months after transcatheter arterial microembolization was 71.4% (95% confidence interval, 55.4-84.3%).

CONCLUSION

Transcatheter arterial microembolization is a safe and effective treatment for persistent trapezius myalgia. Further evaluation with a control group is needed to confirm the effects of transcatheter arterial microembolization.

LEVEL OF EVIDENCE

Level 4, Case Series.

Short-term follow-up of embolization of hip synovitis

Background

Osteoarthritis (OA) is the most frequent joint disease, affecting 10% of men and 18% of women older than 60 years worldwide. Traditionally, treatment is based in pain management with joint replacement of end-stage disease. In this setting, transcatheter embolization has emerged as an alternative in reduction of pain in patients with OA.

Case presentation

A 77 years-old female presenting with two previous deep vein thrombosis and 10 years of hip pain. Magnetic resonance demonstrated a focal area of enhanced pericapsular signal near the superolateral margin of the acetabulum. Embolization of branches of the ascending branch of the lateral femoral circumflex artery was performed, with decrease of the pain and improvement in the image and her walking ability in a four-month follow-up.

Conclusion

This case report have shown that embolization of hip synovitis is feasible with early clinical success, in tune with the findings of genicular and shoulder embolization. Studies with more patients and long-term results are necessary to corroborate this finding.

Level of evidence

4

Transcatheter arterial embolization of abnormal vessels as a treatment for lateral epicondylitis refractory to conservative treatment: a pilot study with a 2-year follow-up

BACKGROUND

Abnormal vessels and accompanying nerves are possible sources of pain with lateral epicondylitis. The purpose of this study was to describe the safety and efficacy of transcatheter arterial embolization (TAE) for lateral epicondylitis resistant to conservative treatment.

METHODS

This prospective study was conducted in 24 patients with lateral epicondylitis resistant to conservative treatments for more than 3 months, with a symptom duration longer than 6 months, and with moderate to severe pain who were treated with TAE between March 2013 and October 2014. Two patients were lost to follow-up, and the remaining 22 patients were followed up for 2 years after TAE.

RESULTS

Abnormal vessels were identified in all of the patients. No major adverse events were observed. The Quick Disabilities of the Arm, Shoulder and Hand scores at baseline significantly decreased at 1, 3, 6, and 24 months after treatment (50.8 vs 23.4, 8.3, 5.3, and 2.7, respectively; all P < .001). There was a statistically significant (P < .001) change from baseline to the last observed value in all of the clinical parameters, including visual analog scale pain score, Patient-Rated Tennis Elbow Evaluation score, and pain-free grip strength. Magnetic resonance images obtained 2 years after TAE showed an improvement in tendinosis and tear scores compared with baseline, and no patients showed bone marrow necrosis, obvious cartilage loss, or muscle atrophy.

CONCLUSION

TAE could be one possible treatment option for patients with lateral epicondylitis that fails to improve with conservative treatments.

Short-term results of transcatheter arterial embolization for abnormal neovessels in patients with adhesive capsulitis: a pilot study

BACKGROUND

Neovessels and accompanying nerves are possible sources of pain. We postulated that transcatheter arterial embolization of abnormal neovessels would relieve pain and symptoms in patients with adhesive capsulitis.

METHODS

Adhesive capsulitis was treated by transcatheter arterial embolization in 7 patients. Adverse events, changes in visual analog scale scores for night pain and overall shoulder pain, and changes in range of motion and American Shoulder and Elbow Surgeons scores were assessed at 1 week and at 1, 3, and 6 months after the procedure.

RESULTS

Abnormal neovessels were identified at the rotator interval in all patients. No major or minor adverse events were associated with the procedures. Transcatheter arterial embolization rapidly decreased nighttime pain scores from 67 ± 14 mm to 27 ± 14 mm at 1 week after the procedure, with further improvement at 1 and 6 months (6 ± 8 mm and 2 ± 5 mm, respectively). The American Shoulder and Elbow Surgeons score significantly improved from 17.8 ± 4.5 to 39.8 ± 12.0, 64.3 ± 13.9, and 76.2 ± 4.4 at 1, 3, and 6 months, respectively.

CONCLUSION

All patients with adhesive capsulitis had abnormal neovessels at the rotator interval. Transcatheter arterial embolization was feasible, relieved unrelenting pain, and restored shoulder function.