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.

Clinical results of ultrasound-guided intra-arterial embolization targeting abnormal neovessels for plantar fasciitis: 66 cases with up to 4 years of follow-up.

BACKGROUND: Plantar fasciitis (PF) is the most common cause of chronic heel pain, affecting young and older patients. METHODS: This retrospective study included patients with PF refractory to conservative treatment who underwent intra-arterial embolization of abnormal neovessels. All patients received temporary embolic material through a needle percutaneously inserted into the posterior tibial artery. The numeric rating scale (NRS) pain score, American Orthopaedic Foot and Ankle Society (AOFAS) score, and procedure-related adverse events were evaluated. RESULTS: Between January 2020 and February 2022, 66 patients with PF were treated with intra-arterial embolization without major adverse events. The NRS pain score improved significantly, and the AOFAS score increased from 65.8 pre-treatment to 92.8 at 1 year post-treatment. The treatment effect was maintained until the final follow-up (mean duration: 30.9 months). CONCLUSIONS: Ultrasound-guided intraarterial embolization using temporary embolic material may be effective for PF. LEVEL OF EVIDENCE: IV.

Genicular artery embolization as a treatment for refractory osteoarthritis related knee pain.

Genicular artery embolization (GAE) is a minimally invasive outpatient therapy for osteoarthritis (OA) related knee pain, refractory to conservative management. This intervention targets neovasculature which arises in the setting of angiogenesis in OA. Various clinical trials highlighted in this manuscript suggest that GAE is effective in durably reducing OA-related knee pain, with a limited adverse event profile. This review also explores the clinical evaluation of GAE candidates, genicular artery anatomy, technical components of the procedure, and imaging from various GAE embolizations. It also discusses future directions for research which may illuminate predictors of clinical success as well as avenues for evolution in the GAE treatment.

Alteration of chronic inflammatory status by transarterial embolization in frozen shoulder evaluated by fluorine-18 fluorodeoxyglucose positron-emission tomography/computed tomography.

BACKGROUND: Frozen shoulder (FS) is speculated to have an inflammatory etiology. On angiography, abnormal angiogenesis is observed around the affected shoulder, suggesting a possible source of inflammation and pain. The effectiveness and safety of transarterial embolization (TAE) targeting abnormally proliferating blood vessels have been reported. This study investigated changes in chronic inflammatory and hypoxic status before and after TAE in FS by [18F]-fluoro-2-deoxyglucose (FDG) positron-emission tomography/computed tomography as a possible mechanism of the therapeutic response to TAE. METHODS: Fifteen patients with unilateral FS, persistent for more than 6 months, who were refractory to conservative treatments, underwent TAE using the temporary embolic agent imipenem/cilastatin. Patients underwent positron-emission tomography/computed tomography with FDG (as a biomarker of inflammation) before and 8 weeks after TAE. Regional uptake was evaluated by the maximum standardized uptake value. The lesion-side-to-(contralateral-) normal-side uptake ratio was also calculated. Pain and functional scales, range-of-motion, and laboratory tests, including white blood cell, C-reactive protein, interleukin 6, vascular endothelial growth factor, and tumor necrosis factor α were evaluated. RESULTS: On FDG-PET, the average maximum standardized uptake value of the lesion-side was significantly greater than that of the normal-side (maximum standardized uptake value before TAE: 3.11 ± 1.25 vs 1.95 ± 1.15, P = .0001; 8-weeks post-TAE: 2.36 ± 0.74 vs 1.78 ± 0.69, P = .0002). The mean lesion-side-to-(contralateral-) normal-side uptake ratios before TAE (1.71 ± 0.60) decreased after TAE (1.37 ± 0.29, P = .011). The decrease of FDG uptake (-21.1 ± 12.2%) showed a significant correlation with the change in the pain scale score (r = -0.56, P = .039) and extension score (r = -0.59, P = .026). CONCLUSION: Chronic inflammation in FS, as demonstrated by FDG uptake, was decreased after TAE. Thus, chronic inflammation is likely to be an underlying mechanism that should be targeted for symptomatic improvement of frozen shoulder.

Transarterial Embolization of Neovascularity for Refractory Nighttime Shoulder Pain: A Multicenter, Open-Label, Feasibility Trial.

PURPOSE: To assess the feasibility of transarterial embolization (TAE) for recalcitrant nighttime shoulder pain in a multicentric study. MATERIALS AND METHODS: This prospective, open-label, feasibility trial included 100 patients treated at 5 institutions. TAE was performed in 76 patients with adhesive capsulitis (AC) and 24 patients with symptomatic rotator cuff tears (sRCTs). The ipsilateral radial artery was punctured, and imipenem/cilastatin sodium was infused as an embolic agent. Adverse events, 10 point pain numerical rating scale (NRS), range of motion (ROM) of the shoulder joint, and quality of life (via the EuroQol-5D [EQ-5D]) were evaluated. RESULTS: All patients exhibited neovascularity on baseline angiography, and all TAE procedures were performed successfully. No patient experienced a major adverse event. The mean nighttime pain NRS scores at baseline and 1, 3, and 6 months after TAE were 6.4 ± 2.2, 3.4 ± 2.6, 2.3 ± 2.5, and 1.6 ± 2.2, respectively (for all, P < .001). The mean ROM of anterior elevation at baseline and 1, 3, and 6 months after TAE were 97° ± 29°, 119° ± 28°, 135° ± 27°, and 151° ± 17°, respectively (for all, P < .001). The mean EQ-5D scores at baseline and 1, 3, and 6 months after TAE were 0.63 ± 0.17, 0.73 ± 0.16, 0.80 ± 0.17, and 0.84 ± 0.17, respectively (for all, P < .001). There was no significant difference in the clinical success rate between the AC and sRCT groups. CONCLUSIONS: TAE for nighttime shoulder pain caused by AC and sRCTs was feasible with sufficient safety and efficacy.

Intra-Arterial Infusion of Imipenem/Cilastatin Sodium through a Needle Inserted into the Radial Artery as a New Treatment for Refractory Trapeziometacarpal Osteoarthritis.

PURPOSE: To evaluate the efficacy and safety of intra-arterial infusion of temporary embolic material with/without radiographic monitoring via a needle placed into the radial artery to occlude abnormal neovessels for trapeziometacarpal osteoarthritis. MATERIALS AND METHODS: Thirty-one patients having Eaton stage II or III osteoarthritis, with a symptom duration longer than 6 months, resistant to conservative therapy for at least 3 months were prospectively enrolled. All procedures were performed by infusing imipenem/cilastatin sodium through a 24-gauge needle that was percutaneously inserted into the radial artery. Seven patients underwent the procedure with fluoroscopy, and 21 patients underwent the procedure without fluoroscopy. The mean Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, numerical rating scale (NRS), and Patient Global Impression of Change (PGIC) scale were evaluated before and at 2, 6, and 24 months after the first procedure. RESULTS: Technical success was 100%. The mean procedure time (from the beginning of local anesthesia to the removal of needle) was 2.9 minutes ± 1.6. The QuickDASH score improved from the baseline to 2, 6, and 24 months (49.2 ± 11.2 vs 22.1 ± 11.2, 20.9 ± 16.6, and 19.5 ± 16.1, respectively, all P <.001). The NRS improved from the baseline to 2, 6, and 24 months (7.2 ± 1.1 vs 3.1 ± 1.8, 2.8 ± 2, and 2.5 ± 2.1, respectively, all P <.001). Improvement on PGIC was observed in 84%, 81%, and 77% of patients at 2, 6, and 24 months, respectively. No major adverse events were encountered. CONCLUSIONS: Intra-arterial infusion of temporary embolic material is a feasible treatment option for trapeziometacarpal osteoarthritis.

Association between Baseline Osteoarthritic Features on MR Imaging and Clinical Outcome after Genicular Artery Embolization for Knee Osteoarthritis.

PURPOSE: To explore the association between baseline osteoarthritis (OA)-related magnetic resonance (MR) imaging features and pain reduction after genicular artery embolization (GAE) in patients with mild-to-moderate symptomatic knee OA resistant to conservative therapy. MATERIALS AND METHODS: This was a retrospective analysis of patients with mild-to-moderate symptomatic knee OA treated with GAE using imipenem-cilastatin sodium. The clinical outcome was scored at baseline and 6 months after treatment using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). MR images were scored using the MR imaging osteoarthritis knee score. Linear regression was used to evaluate associations of before-treatment MR imaging scores with WOMACpain and WOMACtotal reduction after 6 months. RESULTS: Fifty-four patients (22.2% male; median age, 69.4 years; median WOMACpain at baseline, 12) were evaluated. Of all OA features scored, a higher cartilage full-thickness defect score showed the strongest association with less reduction of both WOMACpain (B,-0.63 [95% confidence interval (CI), -0.91 to -0.34]; P < .001) and WOMACtotal scores (B, -1.77 [95% CI, -2.87 to -0.67]; P < .001) following treatment. The presence of grade 2-3 effusion synovitis (B, -2.99 [95% CI, -5.39 to -0.60]) bone marrow lesions (B, -0.52 [95% CI, -0.86 to -0.19]), osteophytes (B, -0.21 [95% CI, -0.36 to -0.06]), and cartilage defect surface area score (B, -0.25 [95% CI -0.42 to -0.08]) all showed a significant association with less WOMACpain reduction (all P < .05). CONCLUSIONS: In patients with mild-to-moderate symptomatic knee OA treated with GAE, the presence and severity of full-thickness cartilage defects, effusion synovitis, bone marrow lesions, osteophytes, and cartilage surface area scores at baseline are associated with less favorable clinical outcomes at 6 months.

Inflammation and Hypervascularization in a Large Animal Model of Knee Osteoarthritis: Imaging with Pathohistologic Correlation.

PURPOSE: To evaluate if synovial inflammation and hypervascularization are present in a dog model of knee osteoarthritis and can be detected on conventional magnetic resonance imaging (MRI), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), contrast-enhanced magnetic resonance imaging (CE-MRI), and quantitative digital subtraction angiography (Q-DSA) imaging. MATERIALS AND METHODS: Six dogs underwent MRI and angiography of both knees before and 12 weeks after right knee anterior cruciate ligament injury. Synovial vascularity was evaluated on CE-MRI, DCE-MRI, and Q-DSA by 2 independent observers. Synovial inflammation and vascularity were histologically scored independently. Cartilage lesions and osteophytes were analyzed macroscopically, and cartilage volumetry was analyzed by MRI. Vascularity and osteoarthritis markers on imaging were compared before and after osteoarthritis generation, and between the osteoarthritis model and the control knee, using linear mixed models accounting for within-dog correlation. RESULTS: In all knees, baseline imaging showed no abnormalities. Control knees did not develop significant osteoarthritis changes, synovial inflammation, or hypervascularization. In osteoarthritis knees, mean synovial enhancement score on CE-MR imaging increased by 13.1 ± 0.59 (P < .0001); mean synovial inflammation variable increased from 47.33 ± 18.61 to 407.97 ± 18.61 on DCE-MR imaging (P < .0001); and area under the curve on Q-DSA increased by 1058.58 ± 199.08 (P = .0043). Synovial inflammation, hypervascularization, and osteophyte formations were present in all osteoarthritis knees. Histology scores showed strong correlation with CE-MR imaging findings (Spearman correlation coefficient [SCC] = 0.742; P = .0002) and Q-DSA findings (SCC = 0.763; P < .0001) and weak correlation with DCE-MR imaging (SCC = -0.345; P = .329). Moderate correlation was found between CE-MR imaging and DSA findings (SCC = 0.536; P = .0004). CONCLUSIONS: In this early-stage knee osteoarthritis dog model, synovial inflammation and hypervascularization were found on imaging and confirmed by histology.

Reliable patient-reported outcome measure and survivorship of UKA for primary spontaneous osteonecrosis.

PURPOSE: Primary Spontaneous osteonecrosis of the knee (SPONK) was a result of a subchondral insufficiency fracture based on histopathological examinations. There were few studies examining patients who underwent unicompartmental knee arthroplasty (UKA) for the treatment of primary SPONK. The aim of this study was to investigate (1) patient-reported outcome measure (PROM), (2) survivorship of revision as end point and (3) survivorship of complication as end point in patients with primary SPONK. METHODS: The clinical examinations of a consecutive series of 61 medial UKAs for primary SPONK of the medial femoral condyle from 2008 to 2012 were evaluated retrospectively at our institution. There were 18 males and 43 females with a mean age of 73.7 years (60-91). In all patients, preoperative radiographs were analyzed according to the stage of primary SPONK. We conducted Kaplan-Meier survival analyses using revision and complications for any reasons as the end point. RESULTS: Mean follow-up was 6.6 years (range 6-10). UKA using Physica ZUK (LIMA Corporate. UD, Italy) for SPONK improved patients' 2011 Knee Society symptom score, patient satisfaction, patient activities, EQ-5D and postoperative ranges of motion compared with their preoperative status (P < 0.01). Revision surgery was required in one knee (1.6%) due to postoperative fracture of the medial tibial plateau after a fall that occurred 6 months postoperatively. The projected rate of survivorship of UKA was 90.4% at 10 years (95% confidence interval 0.80-1). The projected rate of survivorship with complication at end point was 87.7% at 10 years (95% confidence interval 0.76-0.99). CONCLUSION: The present study demonstrated that primary spontaneous osteonecrosis of the knee (SPONK) can be successfully be treated with UKA at a mean follow-up of 6.6 years. LEVEL OF EVIDENCE: II.

Midterm Clinical Outcomes and MR Imaging Changes after Transcatheter Arterial Embolization as a Treatment for Mild to Moderate Radiographic Knee Osteoarthritis Resistant to Conservative Treatment.

PURPOSE: To describe the safety and efficacy of transcatheter arterial embolization for mild to moderate radiographic knee osteoarthritis (OA) that is resistant to conservative treatment. MATERIALS AND METHODS: This prospective study included 72 patients (95 knees) with OA of Kellgren-Lawrence (KL) grade 1-3 and persisting moderate to severe pain that was resistant to conservative management who were treated with transcatheter arterial embolization between July 2012 and March 2016. Clinical outcomes were evaluated at 1, 4, and 6 months and then every 6 months for a maximum of 4 years. The Whole-Organ Magnetic Resonance Imaging Score (WORMS) was evaluated at baseline and at 2 years after embolization in 35 knees. RESULTS: Abnormal neovessels were identified in all cases. There were no major adverse events related to the procedures. Mean Western Ontario and McMaster Universities Osteoarthritis Index pain scores significantly decreased from baseline to 1, 4, 6, 12, and 24 months after treatment (12.1 vs 6.2, 4.4, 3.7, 3.0, and 2.6; all P < .001). The cumulative clinical success rates at 6 months and 3 years after embolization were 86.3% (95% confidence interval [CI], 78%-92%) and 79.8% (95% CI, 69%-87%), respectively. WORMS scores at 2 years after embolization in 35 knees showed significant improvement of synovitis vs baseline (P = .0016) and no osteonecrosis or other evidence indicating aggressive progression of degenerative changes. CONCLUSIONS: Transcatheter arterial embolization significantly improved pain symptoms and clinical function in patients with mild to moderate knee OA that was resistant to conservative treatment.

Clinical Outcomes of Transcatheter Arterial Embolization for Adhesive Capsulitis Resistant to Conservative Treatment.

PURPOSE: To evaluate clinical outcomes of transcatheter arterial embolization (TAE) for adhesive capsulitis resistant to conservative treatments. MATERIALS AND METHODS: This study comprised 25 patients (18 women and 7 men; mean age, 53.8 y; range, 39-68 y) with adhesive capsulitis resistant to conservative treatments. TAE was performed, and adverse events (AEs), pain visual analog scale (VAS) score changes, range of motion (ROM), and American Shoulder and Elbow Surgeons (ASES) scores were assessed. RESULTS: Abnormal vessels were identified in all patients. No major AEs were associated with TAE. One patient was lost to follow-up. The remaining 24 patients were available for final follow-up (mean, 36.1 months; range, 30-44 months). Of the 24 patients, 16 (67%) experienced quick improvement of nighttime pain (ie, VAS scores decreased > 50% from baseline) within 1 week, and 21 (87%) improved within 1 month. In terms of mean overall pain (ie, pain at its worst), VAS scores significantly decreased at 1, 3, and 6 months after treatment (82 mm before treatment vs 52, 19, and 8 mm after treatment; P < .001). ASES scores significantly improved at 1, 3, and 6 months after treatment (16.1 before treatment vs 41.4, 69.1, and 83.5 after treatment; P < .001). No symptom recurrence or late-onset AEs were observed. Shoulder ROM and function further improved during midterm follow-up. CONCLUSIONS: TAE is a possible treatment option for patients with adhesive capsulitis that has failed to improve with conservative treatments.

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.

Extracellular matrix protein tenascin-C is required in the bone marrow microenvironment primed for hematopoietic regeneration.

The BM microenvironment is required for the maintenance, proliferation, and mobilization of hematopoietic stem and progenitor cells (HSPCs), both during steady-state conditions and hematopoietic recovery after myeloablation. The ECM meshwork has long been recognized as a major anatomical component of the BM microenvironment; however, the molecular signatures and functions of the ECM to support HSPCs are poorly understood. Of the many ECM proteins, the expression of tenascin-C (TN-C) was found to be dramatically up-regulated during hematopoietic recovery after myeloablation. The TN-C gene was predominantly expressed in stromal cells and endothelial cells, known as BM niche cells, supporting the function of HSPCs. Mice lacking TN-C (TN-C(-/-)) mice showed normal steady-state hematopoiesis; however, they failed to reconstitute hematopoiesis after BM ablation and showed high lethality. The capacity to support transplanted wild-type hematopoietic cells to regenerate hematopoiesis was reduced in TN-C(-/-) recipient mice. In vitro culture on a TN-C substratum promoted the proliferation of HSPCs in an integrin α9-dependent manner and up-regulated the expression of the cyclins (cyclinD1 and cyclinE1) and down-regulated the expression of the cyclin-dependent kinase inhibitors (p57(Kip2), p21(Cip1), p16(Ink4a)). These results identify TN-C as a critical component of the BM microenvironment that is required for hematopoietic regeneration.

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.

Transcatheter Arterial Embolization for Chronic Prostatitis/Chronic Pelvic Pain Syndrome: A Retrospective Study of 44 Patients.

PURPOSE: To investigate the preliminary treatment outcomes of transcatheter arterial embolization (TAE) for chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). MATERIALS AND METHODS: This retrospective study included patients with refractory CP/CPPS who underwent TAE between April 2022 and February 2023. All patients had persistent pelvic pain for at least 3 months, a total score of at least 15 on the NIH-Chronic Prostatitis Symptom Index (NIH-CPSI), and lacked evidence of infection. All procedures were performed by injecting imipenem/cilastatin sodium (IPM/CS) from bilateral prostatic arteries ± internal pudendal arteries. NIH-CPSI, pain numeric rating scale (NRS), and complications were evaluated at 1, 3, and 6 months after the initial TAE and at the final follow-up. RESULTS: Out of 48 patients, 44 were included in this study, with four excluded because of loss of follow-up. No severe procedure-related complications were observed. Pretreatment and post-treatment evaluations at 1, 3, and 6 months after the initial TAE and at the final follow-up (mean 16.6 months) revealed a decrease in the mean NIH-CPSI scores from 27 ± 6 to 21 ± 8, 20 ± 9, 17 ± 9, and 18 ± 9, respectively (all P < 0.001). Pain NRS scores were also decreased from 7.0 ± 1.6 to 4.8 ± 2.5, 4.1 ± 2.6, 3.7 ± 2.4, and 3.4 ± 2.3, respectively (all P < 0.001). The proportions of clinical success, defined as a reduction of at least 6 points from baseline in the NIH-CPSI, at 6 months after TAE and at the final follow-up were 70 and 64%, respectively. CONCLUSIONS: This study provides evidence of the feasibility of TAE using IPM/CS for CP/CPPS, suggesting both symptomatic improvement and safety.

The formation of an angiogenic astrocyte template is regulated by the neuroretina in a HIF-1-dependent manner.

The vascular and nervous systems display a high degree of cross-talk and depend on each other functionally. In the vascularization of the central nervous system, astrocytes have been thought to sense tissue oxygen levels in hypoxia-inducible factors (HIFs)-dependent manner and control the vascular growth into the hypoxic area by secreting VEGF. However, recent genetic evidences demonstrate that not only astrocyte HIFs but also astrocyte VEGF expression is dispensable for developmental angiogenesis of the retina. This study demonstrates that hypoxia-inducible factor 1 alpha subunit (HIF-1α), a key transcription factor involved in cellular responses to hypoxia, is most abundantly expressed in the neuroretina, especially retinal progenitor cells (RPCs). A neuroretina-specific knockout of HIF-1α (αCre(+)Hif1α(flox/flox)) showed impaired vascular development characterized by decreased tip cell filopodia and reduced vessel branching. The astrocyte network was hypoplastic in αCre(+)Hif1α(flox/flox) mice. Mechanistically, platelet-derived growth factor A (PDGF-A), a mitogen for astrocytes, was downregulated in the neuroretina of αCre(+)Hif1α(flox/flox) mice. Supplementing PDGF-A restored reduced astrocytic and vascular density in αCre(+)Hif1α(flox/flox) mice. Our data demonstrates that the neuroretina but not astrocytes acts as a primary oxygen sensor which ultimately controls the retinal vascular development by regulating an angiogenic astrocyte template.

Bone marrow-derived cells serve as proangiogenic macrophages but not endothelial cells in wound healing.

Bone marrow-derived cells (BMDCs) contribute to postnatal vascular growth by differentiating into endothelial cells or secreting angiogenic factors. However, the extent of their endothelial differentiation highly varies according to the angiogenic models used. Wound healing is an intricate process in which the skin repairs itself after injury. As a process also observed in cancer progression, neoangiogenesis into wound tissues is profoundly involved in this healing process, suggesting the contribution of BMDCs. However, the extent of the differentiation of BMDCs to endothelial cells in wound healing is unclear. In this study, using the green fluorescent protein-bone marrow chim-eric experiment and high resolution confocal microscopy at a single cell level, we observed no endothelial differentiation of BMDCs in 2 acute wound healing models (dorsal excisional wound and ear punch) and a chronic wound healing model (decubitus ulcer). Instead, a major proportion of BMDCs were macrophages. Indeed, colony-stimulating factor 1 (CSF-1) inhibition depleted approximately 80% of the BMDCs at the wound healing site. CSF-1-mutant (CSF-1(op/op)) mice showed significantly reduced neoangiogenesis into the wound site, supporting the substantial role of BMDCs as macrophages. Our data show that the proangiogenic effects of macrophages, but not the endothelial differentiation, are the major contribution of BMDCs in wound healing.

Transcatheter arterial embolization using imipenem/cilastatin sodium for tendinopathy and enthesopathy refractory to nonsurgical management.

PURPOSE: To evaluate the feasibility and effects of transcatheter arterial embolization with imipenem/cilastatin sodium (CS) to treat tendinopathy and enthesopathy that are refractory to traditional nonsurgical management. MATERIALS AND METHODS: Transcatheter arterial embolization with imipenem/CS as an embolic agent was performed in seven patients (five men; mean age, 51.7 y) with tendinopathy and enthesopathy (patellar tendinopathy, n = 1; rotator cuff tendinopathy, n = 2; plantar fasciitis, n = 1; lateral epicondylitis, n = 1; iliotibial band syndrome, n = 1; and Achilles insertion tendinopathy, n = 1). All patients had unrelenting pain at the site of tendinopathy and enthesopathy before the procedure. Technical success, adverse events, and changes in visual analog scale (VAS) scores were assessed. RESULTS: All procedures were technically successful, and no major adverse events developed. Compared with before the procedure, mean VAS scores were significantly decreased at 1 day, 1 week, and 1 and 4 months after the procedure (72.7 mm±9.9 vs 17.4 mm±18.5, 16.0 mm±18.1, 13.7 mm±7.3, and 9.7 mm±6.8, respectively; all P< .001). CONCLUSIONS: Transcatheter arterial embolization with imipenem/CS was feasible and effectively relieved unrelenting pain associated with tendinopathy and enthesopathy.

Transarterial Embolization for Refractory Overuse Sports Injury: Pictorial Case Reports.

Transarterial embolization for the treatment of chronic musculoskeletal diseases is gaining increasing interest in the field of interventional radiology. Overuse sports injury is defined as an injury occurring in the absence of a single, identifiable traumatic cause. In the treatment of this condition, there is a need for reliable results and a quick return to activity. Minimally invasive treatments with short periods of missed practice are required. Intra-arterial embolization has the potential to meet this need. In this article, we describe cases of embolization for refractory overuse sports injuries including patellar tendinopathy, pes anserine, plantar fasciitis, triangular fibrocartilage complex injury, hamstring injury, infrapatellar fat pad inflammation, Achilles tendinopathy, delayed union metatarsal bone fracture, lumbar spondylolysis, and repetitive hamstrings strain.

Elbow Artery Embolization for Lateral Epicondylitis.

Lateral epicondylitis, also known as tennis elbow, is characterized by a low-grade inflammatory process in the lateral aspect of the elbow. Symptoms are typically treated conservatively, and most patients show resolution or improvement of symptoms within a few months. For those with refractory symptoms, treatment options are limited with questionable benefit. Embolization of the arteries supplying the elbow decreases the neo-vascularity seen in epicondylitis. The procedure may result in marked improvement in pain and function, which has shown to be durable.