Cornerstones of CT urography: a shared document by the Italian board of urogenital radiology.

CT urography is a single term used to refer to different scanning protocols that can be applied for a number of clinical indications. If, on the one hand, this highlights the role of the radiologist in deciding the most suitable technique to perform according to the patient's needs, on the other hand, a certain confusion may arise due to the different technical and clinical variables that have to be taken into account. This has been well demonstrated by a previous work based on an online questionnaire administered to a population of Italian radiologists that brought out similarities as well as differences across the national country. Defining precise guidelines for each clinical scenario, although desirable, is a difficult task to accomplish, if not even unfeasible. According to the prementioned survey, five relevant topics concerning CT urography have been identified: definition and clinical indications, opacification of the excretory system, techniques, post-processing reconstructions, and radiation dose and utility of dual-energy CT. The aim of this work is to deepen and share knowledge about these main points in order to assist the radiology in the daily practice. Moreover, a synopsis of recommendations agreed by the Italian board of genitourinary imaging is provided.

CT-urography: a nationwide survey by the Italian Board of Urogenital Radiology.

Computed tomography-urography is currently the imaging modality of choice for the assessment of the whole urinary tract, giving the possibility to detect and characterize benign and malignant conditions. In particular, computed tomography-urography takes advantage from an improved visualization of the urinary collecting system due to acquisition of delayed scan obtained after excretion of intravenous contrast medium from the kidneys. Nevertheless, the remaining scans are of great help for identification, characterization, and staging of urological tumors. Considering the high number of diseases, urinary segment potentially involved and patients' features, scanning protocols of computed tomography-urography largely vary from one clinical case to another as well as selection and previous preparation of the patient. According to the supramentioned considerations, radiation exposure is also of particular concern. Italian radiologists were asked to express their opinions about computed tomography-urography performance and about its role in their daily practice through an online survey. This paper collects and summarizes the results.

18F-FDG PET reveals unique features of large vessel inflammation in patients with Takayasu's arteritis.

PURPOSE: The object of this study was to assess whether 18F-fluorodeoxyglucose PET/CT (FDG PET/CT) provides novel information in patients with Takayasu's arteritis (TA) in addition to that provided by current activity assessment, to analyse the effects of possible confounders, such as arterial grafts, and to verify whether PET/CT could be informative in lesions <4 mm thick. METHODS: We studied 30 patients with TA, evaluated from October 2010 to April 2014 by both PET/CT and magnetic resonance imaging (MRI). All arterial lesions were evaluated by PET both qualitatively (positive/negative) and semiquantitatively (maximum standardized uptake value, SUVmax), and the thickness of lesions in the MRI field of view was evaluated. In a per-patient analysis, the relationships between the PET data and acute-phase reactants and NIH criteria for active TA were evaluated. In a per-lesion analysis, the relationships between the PET features of each lesion and MRI morphological data were evaluated. The effects of the presence of arterial grafts were also evaluated. RESULTS: Increased FDG uptake was seen in 16 of 30 patients (53%) and in 46 of 177 vascular lesions (26%). Significant periprosthetic FDG uptake was seen in 6 of 7 patients (86%) with previous vascular surgery and in 10 of 11 of grafts (91%). Graft-associated uptake influenced the PET results in three patients (10%) and the SUVmax values in five patients (17%). Of 39 lesions with significant FDG uptake, 15 (38%) were <4 mm thick. Lesion thickness was correlated with lesion SUVmax in FDG-avid lesions only. FDG arterial uptake was not associated with systemic inflammation or NIH criteria. CONCLUSIONS: PET/CT reveals unique and fundamental features of arterial involvement in TA. PET/CT may be useful in the assessment of local inflammatory and vascular remodelling events independent of systemic inflammation during follow-up, even in lesions in which the arterial wall is <4 mm. The presence of arterial grafts is a potential confounder. Prospective studies are required to correlate PET findings with relevant clinical outcomes.

Pancreatic fistula: interventional radiological treatment by collection. Jejunal loop internal drainage.

Pancreaticoduodenectomy is a major surgical procedure associated with various and important complications, often difficult to be managed. Pancreatic fistula is due to leakage of pancreatic juice in the abdominal cavity and is the main and most frequent complication after pancreatic surgery. The treatment of pancreatic fistula may change according to degree. Interventional radiology (IR) can offer powerful minimally invasive alternatives in managing pancreatic fistulas. We report the case of a patient affected by ampullar adenocarcinoma who underwent pancreaticoduodenectomy. Surgery was complicated by high-flow pancreatic fistula treated conservatively with CT guided percutaneous transhepatic drainage. Due to persistent leak of pancreatic fluid the abdominal effusion was drained percutaneously in the jejunal loop by Interventional radiology. KEY WORDS: Pancreatic fistula, Jejunal loop internal drainage, Radiological treatment.

Takayasu arteritis: intravascular contrast medium for MR angiography in the evaluation of disease activity.

OBJECTIVE: Takayasu arteritis is difficult to diagnose, and the evaluation of disease activity is even more challenging. Laboratory, clinical, and radiologic criteria are limited indicators of disease activity. Gadofosveset trisodium is a recently introduced intravascular contrast agent. In this study we sought to investigate a correlation between clinical activity and enhancement of vascular wall thickening in patients with Takayasu arteritis who underwent MR angiography with gadofosveset. SUBJECTS AND METHODS: Twenty-three consecutively registered patients (21 women, two men) with Takayasu arteritis underwent MR angiography of the supraaortic trunks, aorta, and visceral vessels. Intravascular contrast medium was used to correlate thickened vessel wall enhancement with clinical criteria of disease activity. ECG-triggered black-blood first-pass high-resolution steady-state imaging was performed for all patients. RESULTS: Before MR angiography, 14 patients were considered to have active disease. Heterogeneous structural involvement of the vascular tree was found. Twenty of 23 patients (87.0%) had supraaortic trunk involvement, including 12 of the 14 patients (85.7%) with active disease. Seventeen of the 23 patients (73.9%) had aortic and visceral vessel involvement, including 12 of the 14 patients (85.7%) with active disease. On steady state images in the active disease group, the mean signal-to-noise-ratio increased from 17.4 to 35.3 after gadofosveset injection (p > 0.0001), while in the nonactive disease group it increased from 52.8 to 69.6 (p = 0.08). A cutoff of 40% was best for differentiating active from inactive disease (sensitivity, 100%; specificity, 89%; positive predictive value, 92%; negative predictive value, 100%). CONCLUSION: Use of intravascular contrast medium significantly increases the effectiveness of MR angiography in differentiating active and inactive disease.

A Prospective Observational Study on the Efficacy and Safety of Infliximab-Biosimilar (CT-P13) in Patients With Takayasu Arteritis (TAKASIM).

Objectives: Infliximab (IFX) is widely used in patients with refractory Takayasu arteritis (TAK). Recently, the IFX-biosimilar CT-P13 has been introduced for the treatment of inflammatory diseases. The aim of this study was to assess the efficacy and safety of CT-P13 in patients with refractory TAK. Methods: In this prospective, open-label, single-center trial, TAK patients either already on treatment with IFX-originator (switch group) or never treated with IFX (naïve group) received CT-P13 for 52 weeks. The primary outcomes of the study were: (i) number of patients with active disease at month 6; (ii) incidence of treatment-emergent adverse events at month 12. Disease activity was assessed at month 6 and month 12 by clinical evaluation (ITAS-2020, ITAS-ESR, and ITAS-CRP scores) and imaging assessment [magnetic resonance angiography (MRA) and (18F)-FDG-PET]. Results: 23 patients were recruited (21 switch, 2 naïve). At baseline, 7 patients (32%) were classified as active. At month 6, one patient voluntarily dropped out and 7 patients were still active (30%), including one patient started on a different bDMARD at month 2 due to poor disease control. Mean daily dose of prednisone equivalent was significantly lower than baseline (4.2 ± 1.9 mg vs. 4.8 ± 2.1 mg, p = 0.009). At month 12, another patient was excluded because of pregnancy desire. Five patients were classified as active (24%), including two patients started on a different bDMARD at month 2 and month 6. Mean daily dose of prednisone equivalent was significantly lower than baseline (3.3 ± 2.6, p = 0.034). No patient experienced side effects during CT-P13 infusion. Overall, one patient experienced grade 1 adverse event and 9 patients experienced grade 2 adverse events. In no case hospitalization was required. CT-P13 retention rate was 90.9% at month 6 and 90.4% at month 12. Conclusion: In this study, the use of IFX-biosimilar CT-P13 in patients with refractory TAK showed satisfying efficacy and safety profile.

sABLATE: a simplified ABLATE score for prediction of complications and outcome in percutaneous thermal ablation of renal lesions.

The aim of the study is to evaluate the performance of a simplified ABLATE score (sABLATE) in predicting complications and outcome with respect to RENAL, mRENAL, and ABLATE scores. This study included 136 renal lesions in 113 patients (M:F ratio = 2.5; mean age 70.8 years). 98 tumors underwent cryoablation at San Raffaele hospital between 01/2015 and 03/2020, while 37 underwent microwave ablation at San Paolo or Policlinico hospitals between 07/2016 and 03/2020. RENAL, mRENAL, ABLATE, and sABLATE scores were calculated using pre-procedural imaging. Data regarding complications and follow-up were registered. Mann-Whitney U test, ROC analyses, and logistic regression analyses were used for complications. Cox-regression analyses were performed for outcome. Mean tumor diameter was 23.2 mm. Mean and median RENAL, mRENAL, ABLATE, and sABLATE scores were 6.8 and 7, 6.9 and 7, 5.3, and 5, and 3.5 and 3, respectively. During a mean follow-up of 21.9 months (range 1-73), we registered 7 complications, 3 cases of residual disease, and 10 local tumor progressions. Mann-Whitney U test p values for complications for RENAL, mRENAL, ABLATE, and sABLATE were 0.51, 0.49, 0.66, and 0.056, respectively. ROC analyses for complications showed an AUC for RENAL, mRENAL, ABLATE, and sABLATE of 0.57, 0.57, 0.55, and 0.71, respectively. Regarding outcome, HR and p values of Cox-regression analyses were 1.30 and 0.36 for RENAL, 1.33 and 0.35 for mRENAL, 2.16 and 0.01 for ABLATE, 2.29 and 0.004 for sABLATE. sABLATE was the only score close to significance for complications, representing a progress even if not definitive. Regarding outcome, ABLATE confirmed its value, and sABLATE maintained validity despite being a simplification.

ABLATE: a score to predict complications and recurrence rate in percutaneous treatments of renal lesions.

RENAL score has been validated on predicting adverse events and relapses in percutaneous treatments of renal lesions. To better fit interventional issues a modified score (mRENAL) has been introduced, but the only difference from the RENAL score is on the dimensional parameter. However, it remains of surgical derivation while a specific interventional score is missing. This study aims to obtain a specific score (ABLATE) to better quantify the risk of complications and relapses in percutaneous kidney ablation procedures compared to the existing surgical scores. Taking inspiration from previous papers, a score was built to quantify the real difficulties faced in percutaneous treatment of renal lesions. The ABLATE score was used on 71 cryoablations to evaluate its predictivity of complications and relapses. Logistic regression was used to predict complication incidence; Cox-regression was used for relapses; ROC analysis was used to evaluate the accuracy of the different scores. Between January 2014 and November 2019, 71 lesions in 68 patients were treated. Overall, malignant histology was found in 62 lesions (87.3%). Mean and median RENAL, mRENAL, and ABLATE scores were 7.04 and 7, 7.19 and 7, and 5.11 and 4, respectively. Out of 71 treatments, we experienced 3 bleeding with anemia (4.2%), only 2 of which needed further treatment (2.82%). The mean and median RENAL, mRENAL, and ABLATE scores in those with complications were 7.66 and 7.01 (p = 0.69), 8.0 and 7.1 (p = 0.54), and 6.6 and 5.0 (p = 0.38), respectively. Out of 62 malignant lesions, we experienced 2 persistent and 6 recurrent lesions (3.2% and 8.4%, respectively). At Cox-regression analyses, mABLATE score outperformed both RENAL and mRENAL scores in predicting recurrences (HR 1.48; p < 0.001 vs. 1.41; p = 0.1 vs. 1.38: p = 0.07, respectively). The ABLATE score showed to be a better predictor of relapses than RENAL and mRENAL. The small number of complications conditioned a lack of statistic power on complications for all the scores. At the moment to quantify the risks in percutaneous kidney ablation procedures, surgical scores are used. A specific score better performs this task.

Large-vessel Vasculitis Affecting the Aorta and its Branches in Relapsing Polychondritis: Case Series and Systematic Review of the Literature.

OBJECTIVE: To describe the features of large-vessel vasculitis (LVV) as it affects the aorta and its branches in patients with relapsing polychondritis (RP). METHODS: Retrospective data and systematic literature review. RESULTS: Twenty-one patients were identified. LVV diagnosis was subsequent to RP and associated with extrachondral involvement in the majority of patients. Supraaortic vessels were more frequently involved (82%). Fourteen patients (67%) were treated with a conventional synthetic disease-modifying antirheumatic drug (csDMARD) and 7 (33%) with a biological DMARD (bDMARD). Vascular interventional procedures were performed in 10 patients (48%). Premature death due to cardiovascular complications was reported in 3 cases (14%). CONCLUSION: Extraaortic LVV is a serious and overlooked RP manifestation. All patients with RP should be investigated for LVV.

Interventional radiology management of high flow priapism: review of the literature.

INTRODUCTION: High-flow priapism is a persistent partial penile tumescence, related to high flow arterial blood into the corpora. In the treatment of high flow priapism, super-selective embolization is considered treatment of choice when conservative treatment fails as reported in the "EAU Guidelines on Priapism", but there are only few series reporting the outcome, the efficacy of different embolic materials and these studies are uncontrolled and relatively small. OBJECTIVES: The aim of this study is to review the literature to outline the state of the art of this interventional treatment and to analyse the outcome of the different embolic agents. METHODS: Through Medline database we searched all the English-language published articles related to priapism. Keywords were chosen according to MeSH terms. We selected case-series from 1990 to 2020 including at least five cases of high-flow priapism.The variables extracted from the selected articles were: number of patients, mean age, diagnostic imaging modality, mono or bilateral involvement of the arteries, embolization material, technical success, clinical success, complications, recurrence rate and type of reintervention, mean follow up, onset of erectile dysfunction. RESULTS: We analyzed 11 papers.A total of 117 patients, mean age of 30 years, were studied during a period of 8 to 72 months. Technical success average was 99%, varying from 93 to 100%. Clinical success average was 88%, varying from 56 to 100%. After two or more treatments, resolution of priapism was obtained in all patients. No major adverse events registered. Recurrence rate of 21%(25/117) was observed, and only 4 pts underwent surgery. A total of 17 pts (15%) developed erectile dysfunction (ED). CONCLUSION: Our data suggested comparable outcomes using different types of materials.In line with the last evidences we suggest that the choice of the embolic material should be selected basing on the expertise of the operator, the characteristic of the fistula and characteristic of the patients.

Percutaneous Microwave Ablation Versus Cryoablation in the Treatment of T1a Renal Tumors.

PURPOSE: Radiofrequency and cryoablation (Cryo) are the most widely used techniques for the treatment of T1a renal tumors in non-surgical candidates, yet microwave ablation (MWA) has been gaining popularity. In this study, we tested the hypothesis that MWA has comparable safety and efficacy to Cryo in the treatment of selected T1a renal masses. MATERIALS AND METHODS: A retrospective comparative analysis of two patient cohorts was carried out on 83 nodules in 72 consecutive patients treated using image-guided percutaneous ablation with either Cryo or MWA. Patient demographics, tumor histology and characteristics, technical success, procedure time, adverse events and complications, nephrometry score (mRENAL) and renal function were evaluated. Local recurrence was evaluated at 1, 6, 12 and 18-24 months. RESULTS: Fifty-one nodules were treated with Cryo and 32 with MWA (44 and 28 patients, respectively). No statistical differences were observed following Cryo or MWA in median tumor size (p = 0.6), mRENAL (p = 0.1) or technical success (p = 0.8). Median procedure time was significantly lower using microwave ablation (p = 0.003). Median follow-up time was similar in the two groups (22 and 20 months, respectively). Occurrence of complications did not differ (Cryo 5/51, MWA 2/32; p = 0.57), and probability of complications or technical success adjusted for mRENAL did not reach statistical significance (p = 0.6). Renal function was preserved in all patients regardless of techniques. Disease recurrence was observed in 3/47 and in 1/30 treated nodules in the Cryo and MWA groups, respectively, without reaching statistical significance (p = 0.06). CONCLUSION: In the patient population studied, MWA showed comparable safety and efficacy relative to Cryo. LEVEL OF EVIDENCE: Level 3, Non-randomized cohort study.

Cooled radiofrequency ablation technology for painful bone tumors.

Bone metastases are a common cause of cancer-related debilitating pain, especially when -localized in the vertebral column and not responsive to standard treatment. In such cases, various treatment options are available; among these is Radiofrequency, whose role has been rapidly growing over the past few years. In this study, we used the innovative Osteocool RF Ablation System (Medtronic) on a patient with a painful bone metastasis localized in the 5th lumbar vertebra, with encouraging results. The radiofrequency ablation of bone metastases with palliative aim represents an excellent treatment option, as it is a minimally invasive and safe procedure, and can be repeated multiple times.

FDG Uptake by Prosthetic Arterial Grafts in Large Vessel Vasculitis Is Not Specific for Active Disease.

OBJECTIVES: This study investigated the incidence and clinical significance of arterial graft-associated uptake of fluorodeoxyglucose in large-vessel vasculitis (LVV). BACKGROUND: The role of 18F-labeled fluorodeoxyglucose-positron emission tomography/computed tomography ([18F]FDG-PET/CT) in the management of LVV remains to be defined. Although [18F]FDG uptake at arterial graft sites raises concerns regarding active arteritis or infection, its clinical significance in LVV has never been formally studied. METHODS: An observational prospective study sought to identify patients with Takayasu arteritis (TA) undergoing [18F]FDG-PET/CT more than 6 months after graft surgery from a large cohort of patients from 2 tertiary referral centers. [18F]FDG uptake by the graft and native arteries was scored on a scale of 0 to 3 relative to hepatic uptake, and periprosthetic maximum standardized uptake value (SUVmax) was calculated. Periprosthetic [18F]FDG uptake in active disease was compared with that in inactive disease, and arterial progression was assessed by prospective magnetic resonance angiography (MRA). RESULTS: Twenty-six subjects with TA were enrolled. All were afebrile with negative blood culture. Periprosthetic uptake was significant in 23 of 26 patients, and the mean SUVmax was 4.21 ± 1.46. Median periprosthetic [18F]FDG uptake score (3; interquartile range [IQR]: 3 to 3) was higher than in native aorta (1; IQR: 0 to 1; p < 0.001). Graft-specific [18F]FDG uptake was unrelated to disease activity. Despite the high frequency of graft-associated [18F]FDG uptake, sequential MRAs did not reveal arterial progression in 25 of 26 patients; the 1 remaining case showed minor progression limited to native arteries. Nine patients underwent repeated PET/CT scanning without showing changes in graft-specific uptake, despite increased treatment. CONCLUSIONS: Significant [18F]FDG uptake that is confined to arterial graft sites in patients with LVV does not reflect clinically relevant disease activity or progression. To minimize exposure to immunosuppression and in the face of negative blood culture, clinically quiescent arteritis, normal or stably raised C-reactive protein levels, we elected not to escalate treatment and monitor progression with MRA.

A true posterior tibial artery aneurysm--a case report.

Aneurysms of infrapopliteal arteries are rare. The etiology is usually traumatic, and most aneurysms are false. The English-language literature reports only 33 cases of infrapopliteal arterial true aneurysms, of which 8 involve the posterior tibial artery. The etiology of these lesions is unclear; a fibromuscular fibrodysplasia similar to ulnar aneurysm may be hypothesized, but traumatic, atherosclerotic, inflammatory, and other pathological processes are also probably involved. The natural history seems to be related to thrombosis and distal embolism more than to rupture. Surgical indications are debated. Aneurysm repair with a complete restoration of the blood flow through the affected artery is particularly challenging owing to the small size of the vessels, and ligation may be required. We report, to the best of our knowledge, the first case of an atherosclerotic posterior tibial artery true aneurysm successfully treated with aneurysmectomy and end-to-end direct reconstruction with a documented good long-term patency. Clinical features, imaging findings, and surgical management are described; indications and treatments (open or endovascular) are discussed.

Chromogranin-A production and fragmentation in patients with Takayasu arteritis.

BACKGROUND: Chromogranin-A (CgA) is a secretory protein processed into peptides that regulate angiogenesis and vascular cells activation, migration and proliferation. These processes may influence arterial inflammation and remodelling in Takayasu arteritis (TA). METHODS: Plasma levels of full-length CgA (CgA439), CgA fragments lacking the C-terminal region (CgA-FRs) and the N-terminal fragment, CgA1-76 (vasostatin-1, VS-1) were analysed in 42 patients with TA and 20 healthy age-matched controls. Vascular remodelling was longitudinally assessed by imaging. CgA peptides were related to markers of systemic and local inflammation, disease activity and vascular remodelling. RESULTS: Levels of CgA-FRs and VS-1 were increased in TA. Treatment with proton-pump inhibitors (PPIs) and arterial hypertension partially accounted for CgA levels and high inter-patient variability. CgA439, CgA-FRs and VS-1 levels did not reflect disease activity or extent. Markers of systemic or local inflammation correlated with higher CgA-FRs and VS-1 in normotensive patients and with higher CgA439 in hypertensive patients. Treatment with non-biologic anti-rheumatic agents was associated with increased CgA-FRs and a distinctive regulation of CgA processing. Reduced blood levels of anti-angiogenic CgA peptides were associated with vascular remodelling in the groups of patients on PPIs and with arterial hypertension. CONCLUSIONS: The plasma levels of CgA fragments are markedly increased in TA as a consequence of disease- and therapy-related variables. Anti-angiogenic forms of CgA may limit vascular remodelling. Given the effect of the various CgA peptides, it is advisable to limit the therapeutic prescriptions that might influence CgA-derived peptide levels to clearly agreed medical indications until further data become available.

Antalgic flexion of the lower limb: an unusual presentation of aortoiliac infection with psoas muscle abscess-four case reports.

Psoas abscess with aortoiliac infection is rare. Patients are often symptomatic for a long time before the correct diagnosis is made. The authors report 4 cases in which the presenting symptom was an antalgic flexion of the left thigh. In 2 patients the cause was an aortic graft infection with enteric fistula; in the other 2, infection developed after transfemoral endovascular procedures. Open surgical treatment was performed in 3 cases and percutaneous drainage in 1. One surgical patient with a late diagnosis eventually died of sepsis; the other 3 are alive and well at mean follow-up of 14 months.

Systemic pentraxin-3 levels reflect vascular enhancement and progression in Takayasu arteritis.

INTRODUCTION: Progression of arterial involvement is often observed in patients with Takayasu arteritis (TA) thought to be in remission. This reflects the failure of currently used biomarkers and activity criteria to detect smouldering inflammation occurring within arterial wall. Pentraxin-3 (PTX3) is a soluble pattern recognition receptor produced at sites of inflammation and could reveal systemic as well as localized inflammatory processes. We verified whether the blood concentrations of PTX3 and of C-reactive protein (CRP) in patients with Takayasu arteritis (TA) might reflect vascular wall involvement, as assessed by signal enhancement after contrast media administration, and the progression of arterial involvement. METHODS: A cross-sectional single-centre study was carried out on 42 patients with TA that comprised assessment of PTX3, of CRP and erythrocyte sedimentation velocity (ESR). In total, 20 healthy controls and 20 patients with Systemic Lupus Erythematous (SLE) served as controls. Vascular imaging was carried out by magnetic resonance angiography, doppler ultrasonography and computed tomography angiography. RESULTS: Patients with TA and SLE had higher plasmatic PTX3 and CRP concentrations than healthy controls (P = 0.009 and 0.017, respectively). PTX3 levels did not correlate with those of CRP. Patients with active systemic TA had significantly higher concentrations of CRP but similar levels of PTX3 than patients with quiescent disease. In contrast, patients with vascular inflammation detectable at imaging had higher PTX3 concentrations (P = 0.016) than those in which vessel inflammation was not evident, while CRP levels were similar. The concentration of PTX3 but not that of CRP was significantly higher in TA patients with worsening arterial lesions that were not receiving antagonists of tumor necrosis factor-α or interleukin-6. CONCLUSIONS: Arterial inflammation and progression of vascular involvement influence plasma PTX3 levels in TA, while levels of CRP accurately reflect the burden of systemic inflammation. These results support the contention that PTX3 reflects different aspects of inflammation than CRP and might represent a biomarker of actual arteritis in TA.

Treatment of refractory Takayasu arteritis with tocilizumab: 7 Italian patients from a single referral center.

OBJECTIVE: The aim of our study was to evaluate the safety and the efficacy of tocilizumab (TCZ) for refractory Takayasu arteritis (TA). METHODS: We retrospectively assessed the outcome of blocking interleukin (IL)-6 with TCZ in 7 consecutive patients with refractory TA using a combination of clinical and imaging assessment. RESULTS: During a median followup visit at 14 months, 4 patients taking TCZ [including 2 nonresponders to tumor necrosis factor (TNF) inhibitors] achieved clinical response, suggesting a nonredundant role for IL-6 in TA. Inflammatory markers normalized in all patients treated with TCZ. However, vascular progression occurred in 4 patients, suggesting the involvement of other inflammatory pathways and confirming the limitations of erythrocyte sedimentation rate and C-reactive protein for disease activity assessment while taking TCZ. Three patients experienced adverse events and 2 suspended TCZ. CONCLUSION: TCZ may be effective in a subset of patients with refractory TA, even in cases of unresponsiveness to TNF inhibitors. Inflammatory markers are not valid markers of TA activity on TCZ. Further studies are needed to confirm these preliminary observations.