AbstractTissue ablation techniques have emerged as a critical component of modern medical practice and biomedical research, offering versatile solutions for treating various diseases and disorders. Percutaneous ablation is minimally invasive and offers numerous advantages over traditional surgery, such as shorter recovery times, reduced hospital stays, and decreased healthcare costs. Intra‐procedural imaging during ablation also allows precise visualization of the treated tissue while minimizing injury to the surrounding normal tissues, reducing the risk of complications. Here, the mechanisms of tissue ablation and innovative energy delivery systems are explored, highlighting recent advancements that have reshaped the landscape of clinical practice. Current clinical challenges related to tissue ablation are also discussed, underlining unmet clinical needs for more advanced material‐based approaches to improve the delivery of energy and pharmacology‐based therapeutics.
Embolic Agents: Advances in Biomaterials and Technologies for Vascular Embolization (Adv. Mater. 33/2019)
Abstract Minimally invasive transcatheter embolization is a common nonsurgical procedure in interventional radiology used for the deliberate occlusion of blood vessels for the treatment of diseased or injured vasculature. A wide variety of embolic agents including metallic coils, calibrated microspheres, and liquids are available for clinical practice. Additionally, advances in biomaterials, such as shape‐memory foams, biodegradable polymers, and in situ gelling solutions have led to the development of novel preclinical embolic agents. The aim here is to provide a comprehensive overview of current and emerging technologies in endovascular embolization with respect to devices, materials, mechanisms, and design guidelines. Limitations and challenges in embolic materials are also discussed to promote advancement in the field.
Needlestick Injuries in Interventional Radiology Are Common and Underreported
We characterized the effect of systemic therapy given after portal vein embolization (PVE) and before hepatectomy on hepatic tumor and functional liver remnant (FLR) volumes. All 76 patients who underwent right PVE from 2002–2016 were retrospectively studied. Etiologies included colorectal cancer (n = 44), hepatocellular carcinoma (n = 17), cholangiocarcinoma (n = 10), and other metastases (n = 5). Imaging before and after PVE was assessed. Chart review revealed systemic therapy administration, SNaPshot genetic profiling, and comorbidities. Nine patients received systemic therapy; 67 did not. Tumor volume increased 28% in patients who did not receive and decreased −24% in patients who did receive systemic therapy (p = 0.026), with no difference in FLR growth (28% vs. 34%; p = 0.645). Among 30 patients with genetic profiling, 15 were wild type and 15 had mutations. Mutations were an independent predictor of tumor growth (p = 0.049), but did not impact FLR growth (32% vs. 28%; p = 0.93). Neither cirrhosis, hepatic steatosis, nor diabetes impacted changes in tumor or FLR volume (p > 0.20). Systemic therapy administered after PVE before hepatic lobectomy had no effect on FLR growth; however, it was associated with decreasing tumor volumes. Continuing systemic therapy until hepatectomy may be warranted, particularly in patients with genetic mutations.
Pathogenesis of Thromboembolism and Endovascular Management
Venous thromboembolism (VTE), a disease that includes deep venous thrombosis (DVT) and pulmonary embolism (PE), is associated with high mortality, morbidity, and costs. It can result in long-term complications that include postthrombotic syndrome (PTS) adding to its morbidity. VTE affects 1/1000 patients, costs $13.5 billion annually to treat, and claims 100,000 lives annually in the US. The current standard of care for VTE is anticoagulation, though thrombolysis may be performed in patients with PE and threatened limb. This review discusses pathogenesis and medical treatment of VTE and then focuses on endovascular treatment modalities. Mechanical- and catheter-directed thrombolysis (CDT) is discussed, as well as patient selection criteria, and complications. The first prospective study (CaVenT) comparing CDT with anticoagulation alone in acute DVT, despite study shortcomings, corroborates the existing literature indicating improved outcomes with CDT. The potential of the ongoing prospective, multicenter, randomized ATTRACT trial is also highlighted.
Bilateral inferior petrosal sinus sampling: experience in 327 patients
Objective To describe findings and outcomes of 331 bilateral inferior petrosal sinus sampling (BIPSS) procedures performed in 327 patients evaluated for Cushing disease (CD). Materials and methods The radiology department's electronic database was searched to identify all BIPSS procedures (1990–2013). Electronic medical records were used to identify demographics, laboratory, procedural, surgical and pathologic findings. Results A total of 331 BIPSS procedures were performed in 327 patients (254 F, 73 M), mean age 41 (range 7–81) years. The overall technical success rate was 88% for bilateral cannulation, though nearly two-thirds of the technical failures had unilateral sampling that diagnosed CD. Of the 331 BIPSS procedures, 40 were performed without, and 291 with stimulation by Acthrel or desmopressin. Sensitivity was 89–94% for unstimulated BIPSS, 96% for stimulated BIPSS, and 77% for MRI. BIPSS lateralization was accurate in about half of patients, compared with 75% accuracy for MRI. Mean inferior petrosal sinus (IPS):peripheral adrenocorticotropic hormone ratio was 17.3 (SE 1.8) at baseline, and 99.2 (SE 14.8) at 3 min, with decreasing values over time. All patients with follow-up after surgical resection for centralizing BIPSS were reported to be cured, with cortisol levels significantly decreased from 19 to 4 μg/dL (p<0.0001). Complications from BIPSS were rare, including groin hematoma (2.5%), but no thromboembolic complications were seen. Conclusions BIPSS remains the ‘gold standard’ for diagnosing CD. Stimulation with Acthrel or desmopressin is key to increasing specificity. When only one IPS can be successfully cannulated, results may still be diagnostic. BIPSS findings cannot be used to accurately lateralize lesions within the pituitary.