Hemostasis and sealing of air leaks in the lung using high-intensity focused ultrasound

HIFU, a noninvasive and effective treatment for chyluria: 15 years of experience

BACKGROUND

The current treatment therapies for chyluria are often invasive and recurrent. Here, we investigated a novel noninvasive treatment of chyluria with high-intensity focused ultrasound (HIFU) and evaluated its clinical efficacy.

METHODS

155 patients with chyluria were treated with HIFU ablation and followed up over a period of 15 years from May 2000 to December 2015. Routine examinations including urine color observation, color Doppler ultrasound examination, blood serum test of Cr, BUN, and albumin, and detection of urinary chyle were performed before and after the treatment, 1 week, 1 and 6 months post-treatment, and followed up via telephone and other forms. We lost contact with 54 patients during the course of the study.

RESULTS

In the 101 complete cases, the serum levels of Cr and BUN and the color Doppler ultrasound examination did not reveal significant differences before and after the treatment. However, there was a significant increase in the hemoglobin and albumin levels, as well as the body weight after the HIFU treatment. The other 54 patients also showed an improvement of the symptoms after the HIFU treatment before losing contact.

CONCLUSIONS

Our results suggest that the HIFU ablation therapy is a feasible, effective, and noninvasive method for the treatment of chyluria.

A Review of Therapeutic Ablation Modalities

Understanding basic science and technical aspects is essential for scientists and engineers to develop and enhance ablative modalities, and for clinicians to effectively apply therapeutic ablative techniques. An overview of ablative modalities, anatomical locations, and indications for which ablations are performed is presented. Specifically, basic concepts, parameter selection, and underlying biophysics of tissue injury of five currently used therapeutic ablative modalities are reviewed: radiofrequency ablation (RFA), cryoablation (CRA), microwave ablation (MWA), high-intensity focused ultrasound (HIFU), and chemical ablation (CHA) (ablative agents: acetic acid, ethanol, hypertonic sodium chloride, and urea). Each ablative modality could be refined for expanding applications, either independently or in combination, for future therapeutic use.

High-intensity focused ultrasound ablation: an effective and safe treatment for secondary hypersplenism

OBJECTIVE

Hypersplenism is a common disease. The conventional treatment is splenectomy and partial splenic embolization; however, both of them have high complication rates and technical defects. Therefore, safer and more effective techniques should be considered for the treatment of hypersplenism. High-intensity focused ultrasound (HIFU) may provide an effective and safe way for treatment of hypersplenism. Therefore, we conducted this study to assess the safety and efficacy of HIFU in treatment of secondary hypersplenism.

METHODS

A total of 28 patients who suffered from secondary hypersplenism were treated with HIFU ablation. All patients who underwent HIFU were closely followed-up over a year. MRI scan was performed, and the spleens were observed. Blood counts and liver function tests were also carried out.

RESULTS

In the follow-up process, the levels of white blood cells and platelets in the blood after HIFU were significantly higher than those before HIFU, liver function also improved after HIFU treatment. In addition, the symptoms were ameliorated significantly or even disappeared. The MRI showed that the ablation area had turned into a non-perfused volume, and after 12 months of HIFU ablation, the ablated area shrank evidently; the sunken spleen formed a lobulated shape and the splenic volume decreased.

CONCLUSION

HIFU ablation is a safe, effective and non-invasive approach for secondary hypersplenism.

ADVANCES IN KNOWLEDGE

For the first time we used HIFU ablation to treat secondary hypersplenism. It not only expands indications of HIFU but also provides better choice for the treatment of secondary hypersplenism.

Radiofrequency thermocoagulation of lung tumours. Where we are, where we are headed

Only 25% of all lung cancers are diagnosed in an early stage allowing surgical treatment. Primary tumours usually concerning lung metastasis are breast, colon, kidney, uterus/cervix, prostate, and head and neck tumours. During recent years many publications have confirmed the effectiveness and reliability of lung radiofrequency ablation (RFA) alone or together with other techniques (chemotherapy, radiotherapy...). Results suggest that survival increase and curative rates of lung radiofrequency are similar to those achieved by more aggressive procedures and present lower rates of complications. Pneumothorax, pleural effusion and alveolar haemorrhage are the most frequent complications. Indications for lung RFA must be individually evaluated by lung cancer committees. Percutaneous lung RFA may be useful in patients with pulmonary primary tumours and metastases, especially in those with nodules smaller than 3 cm and a peripheral location (>1 cm from the hilum). PET/CT seems to be the most accurate technique in patient follow up.

Therapeutic opportunities in biological responses of ultrasound

The therapeutic benefits of several existing ultrasound-based therapies such as facilitated drug delivery, tumor ablation and thrombolysis derive largely from physical or mechanical effects. In contrast, ultrasound can also trigger various time-dependent biochemical responses in the exposed biological milieu. Several biological responses to ultrasound exposure have been previously described in the literature but only a handful of these provide therapeutic opportunities. These include the use of ultrasound for healing of soft tissues and bones, the use of ultrasound for inducing non-necrotic tumor atrophy as well as for potentiation of chemotherapeutic drugs, activation of the immune system, angiogenesis and suppression of phagocytosis. A review of these therapeutic opportunities is presented with particular emphasis on their mechanisms. Overall, this review presents the increasing importance of ultrasound's role as a biological sensitizer enabling novel therapeutic strategies.