Therapeutic Ultrasound

Along with being an invaluable diagnostic tool, Ultrasound is also used in the treatment of patients. Using ultrasound as a therapeutic tool began in the 1940’s. There are now many types of ultrasound therapies for patients, and more continue to be researched.

Ultrasound Assisted Thrombolysis

This treatment uses ultrasound to treat blood clots.

DVT, deep vein thrombosis, is a very serious condition where a blood clot forms in a deep vein. These clots usually occur in the legs.  If a blood clot forms in a superficial vein it is not as serious as deep vein clots, which requires emergent care.

Ultrasound-assisted thrombolysis utilizes a small catheter, which contains an ultrasound wire as well as medications. The catheter is then threaded to the area of the clot. The catheter fragments the blood clot. The ultrasound is able to loosen up the blood clot. Clots are formed with fibrin. The ultrasound loosens and separates the fibrin. Then, the medications contained within the catheter dissolve the deep vein clot. The blood clot is usually dissolved within three days.

 HIFU

This therapy uses ultrasound to treat cancers, as well as hemostasis (ultrasound to stop bleeding)

High-Intensity Focused Ultrasound uses ultrasound to focus on an area and destroy tissues that have pathogens (such cancerous tumors). Introduced over fifty years ago, HIFU is recently being tested on many types of cancer.

HIFU works by directly a high frequency sound beam at part of a cancerous tumor. HIFU uses heat to destroy the tissue through ablation, a method of removing tissue like dermabrasion.

If an MRI is used to guide the procedure, it is known as Magnetic Resonance-guided Focused Ultrasound. If ultrasound is used to guide the procedure, it is called Ultrasound-guided Focused Ultrasound.

There are clinical trials being conducted to examine using HIFU for brain and breast cancer, liver, bone and prostate cancer. China has been forefront in conducting clinical trials on HIFU use for many types of cancers. Europe is also conducting trials to determine if HIFU could be used for cancer patients not well enough for surgery.

HIFU has many benefits over traditional treatments such as surgery. It does not have as many side effects as other, more traditional treatments do. HIFU also allows healthy cells to remain, while targeting cancerous cells only.

HIFU is used to treat prostate cancer that is organ-confined (not spreading). It has also been used to treat liver and pancreatic cancers. HIFU has been tested on: kidney cancer, breast cancer, and ovarian cancers.

HIFU cannot be used on tumors that are widespread. In addition, this type of therapy can’t pass through air or solid bone, so certain types of cancer can’t be treated with HIFU. It cannot be used on brain cancer, skin cancer or lung cancers.

Lithotripsy

This therapy uses ultrasound to treat stones.

Discovered in the 1980’s, Lithotripsy uses ultrasound to treat kidney stones (urinary calculosis) or stones located in the gallbladder or liver. These stones can also form in the bladder and ureter. There are calcium stones, as well as cystine, uric acid, and struvite stones. Calcium stones are the most common. They can be as small as grains of sand or very large, like a golf ball. They can block the urinary tract. Stones affect up to 10% of the population and lead to many emergency room visits.

Lithotripsy uses several steps to treat these stones:

Step One – the patient is asked to lie on cushions or the patient may be asked step into a tub of warm water

Step Two – the stones are located by ultrasound, and pinpointed for the next step to occur accurately.

Step Three – around 2 – 8 (thousand) shock waves crush the stones, causing them to fragment into much smaller pieces. The patient may feel a tapping feeling but is given pain medication for any discomfort. The shock waves are sent from a Lithotripsy machine. The ultrasound shatters the stones into small, sand like particles that can be ejected from the body through urination.

Targeted Ultrasound drug delivery

This treatment uses ultrasound to deliver drug therapy to a targeted area.

Along with huge diagnostic benefits, the energy of the ultrasound has the ability open living cells for therapeutic purposes, such as drug delivery. Living cells have a protective membrane that shields the inner cell from harm.  Ultrasound not only opens this membrane, but after drugs are delivered, the cell then closes the outer shell.

Ultrasound is able to open living cells by collapsing bubbles, which is caused by ultrasound. The collapse causes a shock wave, which opens the cell membrane. The drugs are delivered, and then the cell then fixes the ‘hole’ made by the shock wave in a few minutes.

Research is being conducted to see how this type of ultrasound therapy could advance chemotherapy, gene therapy and large-molecule drug delivery.

Ultrasound is non-invasive, and would allow drugs such as chemotherapy drugs to be delivered to specific cells, leaving healthy cells alone. Ultrasound would also only focus on the area of the tumor.

Transdermal Ultrasound Drug Delivery

This treatment uses ultrasound to deliver drug therapy to cells.

Rather than painful injections using needles, ultrasound transdermal drug delivery is able to deliver drugs non-invasively. This therapy could be used for diabetics who traditionally inject insulin. Some drugs, peptides and proteins aren’t able to be delivered this way because they are molecularly large, but additional research is being conducted to conquer this.

 Physical Therapy Ultrasound

Physical therapists use ultrasound in the therapeutic treatment of conditions such as muscle spasms, joint swelling and tendonitis. Peyronie’s disease, a painful disease commonly known for causing penile curvature, can also be helped by ultrasound therapy which breaks down formed scar tissue.

Ultrasound therapy cannot be used around areas of a metal implant, on an area of infection or malignancy (abnormal growth such as cancer). For pregnant women, ultrasound therapy cannot be performed on the abdomen. Epiphyseal areas, known as growth plates, are other areas contraindicated of ultrasound therapy.

To perform this therapy, a wand or probe with a round head is placed on the skin in the area needed. Gel is applied to the probe to provide smooth traction for the probe. The gel also improves the transmission of the ultrasound waves. The frequency of therapeutic ultrasound is around 0.8 to 3.0 MHz. When ultrasound therapy is begun, sound waves pass through the skin. This causes tissues under the skin to vibrate. Although the patient does not feel any heat on the surface, the vibration does cause deep heating within the tissues which is very beneficial. When performing ultrasound therapy, the intensity can be adjusted.  Along with continuous sound waves, the ultrasound can also be pulsed. For patients who have scars, the power intensity is increased to promote breakdown of the scar tissue.

Along with providing deep heat to tissues, ultrasound therapy causes increased blood flow to local areas. This can help decrease a patient’s chronic inflammation or swelling. Some studies are showing ultrasound therapy can also promote healing in bone fractures.  The treatment takes around five minutes, although for patients with scar tissue it can be longer.

 

 
 

 

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