**2.3 Ultrasound interventional therapy for endometriosis**

## *2.3.1 Pelvic endometriosis*

Ultrasound-guided puncture sclerotherapy [16], sclerosing agent selection includes anhydrous ethanol, lauryl alcohol, etc. Anhydrous ethanol is less used due to easy to cause low fever, sharp pain, allergies and drunk-like reactions and other adverse reactions poly(lauryl alcohol), the scientific name of polyoxyethylene lauryl alcohol ether, is called polydocanol in Europe. After the injection into the cyst, the protein of the cell will be precipitated quickly, the double molecular layer of the cell wall will be destroyed, the epithelial cells of the cyst wall will be necrotic, the secretion of the fluid of the cell will be inhibited, and the aseptic inflammation will be produced to make the fibrosis of the cyst wall, so as to achieve the purpose of curing the cyst. The drug is widely used. Before the operation, the number and nature of the cyst were confirmed. Under the guidance of real-time ultrasound positioning, the puncture needle entered the center of the cyst, extracted the fluid from the cyst, rinsed the wall of the cyst repeatedly with normal saline, and finally injected with poly(lauryl alcohol) for retention, with a total volume of <50 ml. The results showed that the total effective rate of ultrasound intervention was 93.75%, which had little effect on ovarian reserve function.

## *2.3.2 Adenomyosis*

High intensity (frequency < 1 MHz) focused ultrasound can be used to treat adenomyosis [17]. High intensity focused ultrasound (HIFU) can promote lowfrequency and high-energy ultrasound to reach the target tissue through the body surface fat. It makes use of the cavitation, mechanical and thermal effects of ultrasound to induce irreversible damage and degeneration of adenomyosis cells. After the operation, the volume of the lesion was reduced, the symptoms of the patients were relieved, and the treatment process was safe.
