Principle, Indications and Advantages of Ultrasound Focused Knife (HEF) for the Treatment of Uterine Fibroids Liu Yuanshui, Department of Minimally Invasive Oncology, Shandong Qianfo Mountain Hospital
Principle of ultrasound ablation technology
The energy of focused ultrasound is not enough to cause damage to tissues in the non-treatment area it passes through. At the same time, the cavitation effect of ultrasound makes the intercellular fluid and intracellular gas molecules form bubbles under the action of positive and negative pressure of ultrasound, and then contract and expand to the final burst, and the energy generated causes cell damage and necrosis. The resulting energy causes cell damage and necrosis. The morphology and size of the focal field of focused ultrasound, as well as the effect and reaction of the tissue to ultrasound, play a decisive role in the depth of ultrasound treatment, the extent of tissue damage and the degree of damage. Therefore, by setting the parameters of the ultrasound transducer, it is possible to achieve the goal of targeting and destroying the lesion without damaging the tissues around the treatment target, thus achieving the goal of non-invasive treatment.
Indications for treatment:
(1) clearly diagnosed uterine fibroids, excluding uterine sarcoma, other lesions of the uterus and non-benign lesions of the cervix.
(2) Fibroids that can be revealed by ultrasound with the monitoring of the treatment equipment.
Relative indications (conditions that can be treated with some medical treatment):
(1) cervical fibroids, submucosal and subplasma fibroids with tissues, and vascular smooth muscle tumors.
(2) Acute and chronic pelvic inflammatory disease.
(3) History of multiple lower abdominal surgeries, history of intestinal adhesions, foreign body placement on the acoustic channel of the lower abdomen.
(4) Those with hard textured surgical scars on the lower abdominal wall that have significant attenuation of the visualized ultrasound.
(5) Those who cannot insist on continuous prone for more than 1 hour.
Contraindications:
(1) Those with uncontrollable hypertension.
(2) Having a history of cerebrovascular accident.
(3) Having a history of myocardial infarction.
(4) History of collagenous connective tissue disease.
(5) History of abdominal radiotherapy.
Ultrasound ablation treatment
① Treatment principle: Using ultrasound can pass through human tissue and focus on the characteristics of a specific target area, the energy is gathered to a sufficient intensity, so that the focal area reaches an instant high temperature and destroys the target tissue, which is manifested in histopathology as coagulative necrosis, also called ablation. This results in the destruction of the lesion area without damage to the tissue outside the lesion area.
② Treatment features:
(1) Image monitoring: Real-time monitoring of ultrasound images is used to identify the planned selected target tumor. The entire treatment process is controlled by the system and provides timely feedback on treatment results.
(2) Accuracy: The energy at the focal point produces coagulative necrosis of the tissue at the focal point with no damage to the surrounding tissue or the tissue on the acoustic channel. The border between the treated and non-treated areas is only 6 to 10 cells wide.
(3) Free movement: The free movement of the focal point and the monitoring probe in space can realize three-dimensional combination scanning treatment, and physicians can choose a fast, flexible and effective treatment plan according to different patients and different tumors.
(4) Thorough treatment: The treatment planning software of Focused Ultrasound Tumor Treatment System can help physicians accurately target and remove the entire tumor tissue. There is no upper limit to the volume of tumor that may be treated.
(5) Controllable treatment: Throughout the treatment process, the real-time imaging technology can provide video feedback to the physician and adjust the treatment dose at any time according to the digital grayscale changes.
(③) Treatment advantage: The whole treatment process is non-invasive, non-bleeding and does not require anesthesia, which truly achieves the treatment of tumors in the body from outside the body and kills tumor tissues. During the treatment process, by moving the ultrasound treatment head and changing the focusing depth of ultrasound, the combined scanning mode of: point-line surface-body is used to ablate the whole myoma in a conformal manner.
Advantageous features of high-energy focused ultrasound treatment
1.Non-invasive treatment
In vitro operation, complete destruction of in vivo lesions.
No incision and no radiological damage.
No need for surgical exposure or puncture guidance.
No damage to the tissue through which the ultrasound passes or normal structures outside the target area.
2.Treatment with low total cost
Significantly shortening the patient’s hospital stay
No blood transfusion during treatment.
Significantly reduce the patient’s complications during and after surgical procedures
Less pain for the patient and faster recovery of the organism after treatment
Reduces the application of broad-spectrum antimicrobials after surgery.
3.Uniform dose distribution of treatment
Extracorporeal scanning treatment, so that the ultrasound energy is evenly distributed within the target area.
Solve the problem that minimally invasive interventional treatment (microwave, radiofrequency, laser, freezing, etc.) rely on the treatment head for energy diffusion, and the treatment dose is not uniformly distributed.
4.Target area tissue lethality treatment
Lethal dose of ultrasound in the target area, non-selective so that any tissue in the target area is completely destroyed.
According to the principle of surgical excision, from outside the body “remove” the lesion in the body.
5.Conformal treatment
Stereomic conformal scanning treatment fully guarantees the complete destruction of in vivo lesions from outside the body.
It is not limited by the shape of the tumor.
6.Treatment not limited by tumor size
It can completely destroy cancer masses of any size in the body.
7.Treatment of selective destruction of blood vessels
Generally, only destroying blood vessels of less than 2mm in diameter in the tumor, which effectively ensures the safety of treatment.
It increases the treatable range of lesions and makes local treatment possible for tumor patients who cannot receive surgery due to vascular anatomical factors; promotes the repair of local normal tissues.
8.Treatment in real time
Stereoscopic localization of tumor during treatment.
The ultrasonic monitoring device monitors the whole treatment process in real time to effectively prevent the occurrence of off-target. Real-time treatment.
9.Treatment with real-time judgment of therapeutic effect
During the treatment process, the changes of sonogram in the target area before, during and after the treatment are used to timely evaluate whether there is coagulative necrosis of tissues and whether there is skin damage in the treatment area.
10.Dose controlled treatment
By judging the efficacy of the target area in real time, the treatment dose is controlled by feedback, so that the lethal dose is uniformly distributed within the target area.
Possible risks of focused ultrasound treatment
(1) Nerve damage.
(2) Adverse reactions in sedation and pain relief.
(3) Mild skin burns.
Careful preparation before treatment and real-time monitoring during treatment can avoid the above risks.
Common reactions after ultrasound ablation of uterine fibroids
1. abdominal wall discomfort: due to intestinal preparation and drug induction before treatment and maintaining a certain position during the operation, most of them improve in one or two days after the operation
2.Muscle aches and pains: there may be muscle aches and pains of different degrees due to maintaining a certain position during the treatment, which will improve after resting and there may be some changes in the first one or two menstrual periods after the treatment: due to the treatment
Stress performance and myoma near the endothelium may have an effect
3. Mild swelling and pain in the lower abdomen, slight swelling and pain in the buttocks and waist: related to the position during treatment, mostly improving in a few days after surgery
4.Small amount of vaginal discharge: may occur when the fibroid is close to the endothelium due to the stimulation of the fibroid, very occasionally there is light blood discharge, keep the vulva clean, mostly improve after menstruation
5.Dizziness and mild nausea: caused by the application of sedative and analgesic drugs during the treatment, which mostly improves after resting after the operation
Typical cases.
1 Myoma situation before treatment: right anterior wall myoma, size 49mmx55mmx43mm
Before ablation 3 months after ablation 1 year after ablation
2 Before treatment: posterior wall leiomyoma, size 51mmx60mmx59mm
Before ablation 3 months after ablation 7 months after ablation