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Acoustic attenuation in the propagation path of focused ultrasound ablation surgery determines the energy loss toward the focal region and is critical to the consequent treatment outcomes. In situ non-invasive, reliable, and accurate measurement is challenging for multi-layered heterogeneous tissues within the focusing angle. A novel measurement approach is proposed and its performance is evaluated using ex vivo porcine tenderloin and bovine heart. A big boiling bubble (i.e., larger than a few millimeters in size) was produced at the focus as a strong reflector inside the tissue, and the echo amplitudes were used to determine the acoustic attenuation. Two models, acoustic ray and energy loss, were developed to derive the equivalent acoustic attenuation coefficient for a focused beam. The measured acoustic attenuation coefficients of ex vivo porcine tenderloin and bovine heart at 0.97 MHz and a thickness of 3 cm are 0.159 ± 0.002 and 0.250 ± 0.005 Np/cm, respectively, which are all within the scope of measured values in the literature. In addition, the echo amplitude is sensitive to the conditions of the propagation path, and the inverse acoustic attenuation coefficient of the silicone gel pad placed in front of the tissue sample was 0.807 ± 0.002 Np/cm, which is comparable to the measurement using the insertion substitution method, 0.766 ± 0.003 Np/cm. Our proposed approach could determine the tissue acoustic attenuation for focused ultrasound ablation surgery reliably and accurately in situ. The easy operating protocol may allow clinical translation and adoption for improved safety and efficacy. [ABSTRACT FROM AUTHOR]

Focused ultrasonic ablation surgery (FUAS) for tumor treatment has emerged as an effective non-invasive therapeutic approach, but its widespread clinical utilization is limited by its low therapeutic efficiency caused by inadequate tumor targeting, single imaging modality, and possible tumor recurrence following surgery. Therefore, this study aimed to develop a biological targeting synergistic system consisting of genetically engineered bacteria and multi-functional nanoparticles to overcome these limitations. Escherichia coli was genetically modified to carry an acoustic reporter gene encoding the formation of gas vesicles (GVs) and then target the tumor hypoxic environment in mice. After E. coli producing GVs (GVs- E. coli) colonized the tumor target area, ultrasound imaging and collaborative FUAS were performed; multi-functional nanoparticles were then enriched in the tumor target area through electrostatic adsorption. Multi-functional cationic lipid nanoparticles containing IR780, perfluorohexane, and banoxantrone dihydrochloride (AQ4N) were coloaded in the tumor to realize targeted multimodal imaging and enhance the curative effect of FUAS. AQ4N was stimulated by the tumor hypoxic environment and synergistically cooperated with FUAS to kill tumor cells. In sum, synergistic tumor therapy involving multi-functional nanoparticles mediated by genetically engineered bacteria overcomes the limitations and improves the curative effect of existing FUAS. Inadequate tumor targeting, single image monitoring mode, and prone tumor recurrence following surgery remain significant challenges yet critical for tumor therapy. This study proposes a strategy for genetically engineered bacteria-mediated multifunctional nanoparticles for synergistic tumor therapy. The multifunctional genetically engineered biological targeting synergistic agent can accomplish tumor-targeting therapy, synergistic FUAS ablation, hypoxia-activated chemotherapy combined with FUAS ablation, and multiple-imaging guidance and monitoring all at the same time, thereby compensating for the shortcomings of FUAS treatment. This strategy could pave the way for the progress of tumor therapy. [Display omitted] [ABSTRACT FROM AUTHOR]

Objective: To evaluate the feasibility, safety, and effectiveness of Focused Ultrasound Ablation Surgery (FUAS) combined with ultrasound-guided suction curettage in the management of Cesarean Scar Pregnancy (CSP).Study Design: We retrospectively analyzed 52 patients with CSP from April, 2017, to December, 2019. All the patients received one session of FUAS, and suction curettage under ultrasound guidance was performed 1-3 days after FUAS. The intraoperative blood loss in suction curettage, duration of vaginal bleeding after curettage, reproductive outcomes, and adverse effects were recorded and analyzed.Results: All the 52 patients completed one session of FUAS combined with suction curettage without serious adverse effects. The mean intraoperative blood loss was 32.81 ± 53.83 mL. 47 (90.38 %) patients had a successful suction curettage with a blood loss of less than 80 mL. 5 (9.62 %) patients had an active bleeding of ≥80 mL; however, the bleeding was stopped effectively by Foley's urinary catheter and no evident bleeding presented when the catheter was removed 24 h later. The mean duration of vaginal bleeding was 7.88 ± 4.24 days. 48 (92.30 %) patients recovered with little vaginal bleeding after curettage. 4 (7.69 %) type III CSP patients experienced late-onset severe bleeding and required UAE or surgery. During 6-36 months of the follow-up period, 12 patients expressed reproductive plan, in which 4 patients delivered by cesarean section, 3 patients had an ongoing pregnancy and 1 patient had an abortion in the early pregnancy.Conclusions: FUAS combined with ultrasound-guided suction curettage is a safe and effective treatment strategy in the management of CSP type I and CSP type II and is particularly advantageous for CSP patients with reproductive requirements. However, further studies are warranted to determine the meticulous inclusion criteria for patients with type III CSP. [ABSTRACT FROM AUTHOR]