James X. Chen

Complication and Readmission Rates following Same-Day Discharge after Percutaneous Renal Tumor Ablation

PURPOSE To evaluate readmission rate and complications in patients undergoing same-day discharge following percutaneous thermal ablation of renal tumors. MATERIALS AND METHODS Patients undergoing same-day discharge following thermal ablation of renal tumors were reviewed. The primary outcome was the rate of readmission within 30 days of same-day discharge. The secondary outcomes included the rate and clinical outcomes of periprocedural complications. RESULTS Same-day discharge occurred in 166/174 patients (95%), of whom 2/166 (1%) required short-term readmission due to pulmonary embolism and acute-on-chronic kidney injury. Both patients recovered without permanent morbidity. Admission due to complications occurred in 8/174 (5%) cases, the majority of which were related to hemorrhage. No significant differences in rates of complications or admission were found between cryoablation and RF ablation. Major complications (Clavien-Dindo grade II or higher, SIR grade C or higher) occurred in 7/174 (4%) cases, the majority related to hemorrhage. All cases were detected in the standard 4 hour postprocedural observation period and managed conservatively. The mean hemorrhage volume was significantly larger in patients requiring admission versus those discharged the same day (289 mL vs 34 mL; P = .02). Higher-volume hemorrhage occurred in larger tumors (mean, 4.0 cm vs 3.0 cm; P = .04). There was no association between major complications and central tumor or age. CONCLUSIONS Routine same-day discharge following percutaneous renal tumor thermal ablation can be performed with a low rate of short-term readmission. The majority of periprocedural complications can be managed conservatively, and patients can be discharged the same day.

Analysis of the Final DENALI Trial Data: A Prospective, Multicenter Study of the Denali Inferior Vena Cava Filter

PURPOSE To report the final 2-year data on the efficacy and safety of a nitinol retrievable inferior vena cava (IVC) filter for protection against pulmonary embolism (PE). MATERIALS AND METHODS This was a prospective multicenter trial of 200 patients with temporary indications for caval filtration who underwent implantation of the Denali IVC filter. After filter placement, all patients were followed for 2 years after placement or 30 days after filter retrieval. The primary endpoints were technical success of filter implantation in the intended location and clinical success of filter placement and retrieval. Secondary endpoints were incidence of clinically symptomatic recurrent PE, new or propagating deep vein thrombosis (DVT), and filter-related complications including migration, fracture, penetration, and tilt. RESULTS Filter placement was technically successful in 199 patients (99.5%). Filters were clinically successful in 190 patients (95%). The rate of PE was 3% (n = 6), with 5 patients having a small subsegmental PE and 1 having a lobar PE. New or worsening DVT was noted in 26 patients (13%). Filter retrieval was attempted 125 times in 124 patients and was technically successful in 121 patients (97.6%). The mean filter dwell time at retrieval was 200.8 days (range, 5-736 d). There were no instances of filter fracture, migration, or tilt greater than 15° at the time of filter retrieval or during follow-up. CONCLUSIONS The Denali IVC filter exhibited high success rates for filter placement and retrieval while maintaining a low complication rate in this clinical trial.

Role of Catheter-directed Thrombolysis in Management of Iliofemoral Deep Venous Thrombosis

The treatment for iliofemoral deep venous thrombosis (DVT) is challenging, as the use of anticoagulation alone can be insufficient for restoring venous patency and thus lead to prolongation of acute symptoms and an increased risk of chronic complications, including venous insufficiency and postthrombotic syndrome (PTS). In these cases, earlier and more complete thrombus removal can ameliorate acute symptoms and reduce long-term sequelae. Endovascular therapies involving the use of pharmacologic, mechanical, and combined pharmacomechanical modalities have been developed to achieve these goals. The most frequently used of these techniques, catheter-directed thrombolysis (CDT), involves the infusion of a thrombolytic agent through a multiple-side-hole catheter placed within the thrombosed vein to achieve high local doses and thereby break down the clot while minimizing systemic thrombolytic agent exposure. Randomized controlled trial results have indicated decreased PTS rates and improved venous patency rates in patients treated with CDT compared with these rates in patients treated with anticoagulation. The use of newer pharmacomechanical techniques, as compared with conventional CDT, reduces procedural times and thrombolytic agent doses and is the subject of ongoing investigations. Endovascular thrombus removal techniques offer a means to improve venous valvular function and decrease the risk of debilitating long-term complications such as PTS and are a promising option for treating patients with iliofemoral DVT. (©)RSNA, 2016.

Tumor Growth Kinetics and Oncologic Outcomes of Patients Undergoing Active Surveillance for Residual Renal Tumor following Percutaneous Thermal Ablation.

PURPOSE To evaluate growth kinetics and oncologic outcomes of patients with renal tumors undergoing active surveillance (AS) for residual viable tumor following percutaneous ablation. MATERIALS AND METHODS Following percutaneous thermal ablation, residual tumor was detected in 21/133 (16%) patients on initial follow-up imaging, and AS was undertaken in 17/21 (81%) patients. Initial tumor volumes and volumes after ablation were assessed from cross-sectional imaging to calculate volumetric growth rate (VGR) and volume doubling time (VDT) of residual tumor. The rate of metastasis, overall survival, and renal cell carcinoma (RCC)-specific survival were compared between patients in the AS group and in the routine follow up group of patients who did not have residual tumor. RESULTS Median tumor volume prior to ablation, after first ablation, and at final follow-up were 25 cm(3), 6 cm(3), and 6 cm(3), respectively, in patients with residual tumor. Stable, mild, and moderate VGR occurred in 8/17 (47%), 4/17 (24%), and 5/17 (29%) cases, respectively. The 4 cases with fastest VDT underwent delayed intervention with ablation (n = 1) and nephrectomy (n = 3) without subsequent residual, recurrence, or metastasis. There was no significant difference in the rates of RCC metastasis, overall survival, or RCC-specific survival between AS and routine follow-up groups. Metastatic RCC and subsequent death occurred in 1 patient in the AS group, after the patient had refused offers for retreatment for local progression over 60.7 months of follow-up. CONCLUSIONS In cases when patients are not amenable to further intervention, AS of residual tumor may be an acceptable alternative and allows for successful delayed intervention when needed.

Randomized Embolization Trial for NeuroEndocrine Tumor Metastases to the Liver (RETNET): study protocol for a randomized controlled trial

BackgroundNeuroendocrine tumors (NETs) are the second most common gastrointestinal malignancy after colon cancer. Up to 90% of patients with NETs develop liver metastases, which are a major determinant of symptoms and survival. Current guidelines recommend embolotherapy for progressive or symptomatic NET liver metastases, but the optimal technique among bland embolization, lipiodol chemoembolization, and drug-eluting bead chemoembolization remains unknown and controversial.Methods/designA prospective, open-label, multicenter randomized controlled trial will be conducted in patients with progressive or symptomatic unresectable NET liver metastases. Patients will be randomized to treatment with bland embolization, lipiodol chemoembolization, or drug-eluting microsphere chemoembolization, with 60 enrollees per arm. The primary endpoint will be hepatic progression-free survival (HPFS) following initial embolotherapy by RECIST criteria. The sample size is powered to detect an HR of 1.78 for HPFS following chemoembolization compared with bland embolization, which was estimated on the basis of existing retrospective studies. Secondary endpoints include overall progression-free survival, duration of symptom control, quality of life, rate of adverse events, and interval between embolotherapy cycles. Interim safety analyses will be performed at 10 and 30 patients per arm.DiscussionThe RETNET trial is a prospective, multicenter randomized controlled trial designed to determine the optimal embolotherapy technique for NET liver metastases.Trial registrationClinicalTrials.gov, NCT02724540. Registered on March 31, 2016.

Endobronchial Forceps-Assisted and Excimer Laser-Assisted Inferior Vena Cava Filter Removal: The Data, Where We Are, and How It Is Done

The recognition of inferior vena cava filter related complications has motivated increased attentiveness in clinical follow-up of patients with inferior vena cava filters and has led to development of multiple approaches for retrieving filters that are challenging or impossible to remove using conventional techniques. Endobronchial forceps and excimer lasers are tools for designed to aid in complex inferior vena cava filter removals. This article discusses endobronchial forceps-assisted and excimer laser-assisted inferior vena cava filter retrievals.

A randomized comparison between an intravenous catheter system with a retractable guidewire and conventional intravenous catheters

Introduction The aim of this study is to compare an intravenous (IV) catheter system which uses a retractable guidewire (RG-IV) designed to facilitate IV placement with a conventional IV (C-IV) catheter control. Materials and methods A prospective, randomized design was used. Patients referred to interventional radiology for outpatient procedures were offered participation. Enrollment occurred between August and November 2013. Patients were assigned to receive the RG-IV or C-IV in a 1:1 randomization scheme. After assignment, up to three attempts by a registered nurse occurred with the assigned device; if all three attempts failed, crossover to the other device occurred. The primary outcome variable was first-attempt success at IV placement. Secondary outcome variables included patient and clinician satisfaction, number of attempts, and time to successful placement. Two hundred twenty patients were enrolled (139 men, 81 women) in the study. Results Of the 220 patients, two were withdrawn prior to IV attempt leaving 218 subjects, 109 in each group. First attempt success (77% RG-IV vs. 82% C-IV, p = 0.5), number of attempts to achieve IV access (1.26 RG-IV vs. 1.29 C-IV, p = 0.98), and time to achieve IV success (2.9 minutes RG-IV vs. 2.7 C-IV, p = 0.82) did not differ between groups. Patient satisfaction with insertion was higher in the C-IV group (4.5/5 vs. 3.9/5, p<0.001) although comfort comparison was not (3.3/5 RG-IV vs. 3.5/5 C-IV, p = 0.15). Conclusions In an interventional radiology outpatient population, the RG-IV and C-IV were comparable in first-attempt success, number of attempts, and time to achieve IV success. Patient satisfaction was higher with C-IV.