Identification of sentinel lymph nodes in esophageal cancer patients using contrast-enhanced EUS with peritumoral injections

Macrophage uptake rate of Sonazoid in breast lymphosonography is highly conserved in healthy controls

Subcutaneous microbubble administration in connection with contrast enhanced ultrasound (CEUS) imaging is showing promise as a noninvasive and sensitive way to detect tumor draining sentinel lymph nodes (SLNs) in patients with breast cancer. Moreover, there is potential to harness the results from these approaches to directly estimate cancer burden, since some microbubble formulas, such as the Sonazoid used in this study, are rapidly phagocytosed by macrophages, and the macrophage concentration in a lymph node is inversely related to the cancer burden. This work presents a mathematical model that can approximate a rate constant governing macrophage uptake of Sonazoid,ki, given dynamic CEUS Sonazoid imaging data. Twelve healthy women were injected with 1.0 ml of Sonazoid in an upper-outer quadrant of one of their breasts and SLNs were imaged in each patient immediately after injection, and then at 0.25, 0.5, 1, 2, 4, 6, and 24 h after injection. The mathematical model developed was fit to the dynamic CEUS data from each subject resulting in a mean ± sd of 0.006 ± 0.005 h-1and 0.4 ± 0.1 h-1for relative lymphatic flow (EFl) andki, respectively. Furthermore, the roughly 25% sd of thekimeasurement was similar to the sd that would be expected from realistic noise simulations for a stable 0.4 h-1value ofki, suggesting that macrophage concentration is highly consistent among cancer-free SLNs. These results, along with the significantly smaller variance inkimeasurement observed compared to relative lymphatic flow suggest thatkimay be a more precise and promising approach of estimating macrophage abundance, and inversely cancer burden. Future studies comparing tumor-free to tumor-bearing nodes are planned to verify this hypothesis.

Contrast-enhanced guided endoscopic ultrasound procedures

Contrast-enhanced endoscopic ultrasound (CH-EUS) can overcome the limitations of endoscopic ultrasound-guided acquisition by identifying microvessels inside inhomogeneous tumours and improving the characterization of these tumours. Despite the initial enthusiasm that oriented needle sampling under CH-EUS guidance could provide better diagnostic yield in pancreatic solid lesions, further studies did not confirm the supplementary values in cases of tissue acquisition guided by CH-EUS. This review details the knowledge based on the available data on contrast-guided procedures. The indications for CH-EUS tissue acquisition include isoechoic EUS lesions with poor visible delineation where CH-EUS can differentiate the lesion vascularisation from the surrounding parenchyma and also the mural nodules within biliopancreatic cystic lesions, which occur in select cases. Additionally, the roles of CH-EUS-guided therapy in patients whose pancreatic fluid collections or bile ducts that have an echogenic content have indications for drainage, and patients who have nonvisualized vessels that need to be highlighted via Doppler EUS are presented. Another indication is represented if there is a need for an immediate assessment of the post-radiofrequency ablation of pancreatic neuroendocrine tumours, in which case CH-EUS can be used to reveal the incomplete tumour destruction.

Comprehensive review of materials, applications, and future innovations in biodegradable esophageal stents

Esophageal stricture (ES) results from benign and malignant conditions, such as uncontrolled gastroesophageal reflux disease (GERD) and esophageal neoplasms. Upper gastrointestinal endoscopy is the preferred diagnostic approach for ES and its underlying causes. Stent insertion using an endoscope is a prevalent method for alleviating or treating ES. Nevertheless, the widely used self-expandable metal stents (SEMS) and self-expandable plastic stents (SEPS) can result in complications such as migration and restenosis. Furthermore, they necessitate secondary extraction in cases of benign esophageal stricture (BES), rendering them unsatisfactory for clinical requirements. Over the past 3 decades, significant attention has been devoted to biodegradable materials, including synthetic polyester polymers and magnesium-based alloys, owing to their exceptional biocompatibility and biodegradability while addressing the challenges associated with recurring procedures after BES resolves. Novel esophageal stents have been developed and are undergoing experimental and clinical trials. Drug-eluting stents (DES) with drug-loading and drug-releasing capabilities are currently a research focal point, offering more efficient and precise ES treatments. Functional innovations have been investigated to optimize stent performance, including unidirectional drug-release and anti-migration features. Emerging manufacturing technologies such as three-dimensional (3D) printing and new biodegradable materials such as hydrogels have also contributed to the innovation of esophageal stents. The ultimate objective of the research and development of these materials is their clinical application in the treatment of ES and other benign conditions and the palliative treatment of malignant esophageal stricture (MES). This review aimed to offer a comprehensive overview of current biodegradable esophageal stent materials and their applications, highlight current research limitations and innovations, and offer insights into future development priorities and directions.