Prostatic Artery Embolization (PAE)
Treating enlarged prostates without the risk of sexual side effects.
Prostatic Artery Embolization (PAE) is a cutting-edge procedure performed to help improve urinary symptoms caused by an enlarged prostate without the risk of sexual side effects. Originally developed in Europe and South America, this procedure is now being studied in the United States. UNC Interventional Radiology is excited to be contributing to this research.
The UNC interventional radiologists encourage any patient or physician who wants more information on PAE to contact them to discuss the options that are available.
PAE: A new minimally-invasive approach at UNC
Prostatic artery embolization is performed through a small puncture in the groin. A catheter is inserted through the artery and directed toward the prostate. Once the catheter is positioned in the artery supplying blood to the prostate, tiny particles are injected that plug up the artery, blocking blood flow. This is called embolization. The process is then repeated on the other side, most commonly through the same original puncture. The procedure can take anywhere from 1-4 hours, depending on the location and size of the prostatic arteries.
The PAE procedure blocks the blood flow to the areas of the prostate that are most affected by benign prostatic hyperplasia (BPH), resulting in death, or necrosis, of isolated areas. Because it is impossible to block all of the blood flow to the prostate, it does not die completely. These areas of necrosis cause the prostate to initially be softer, alleviating some of the pressure that is causing blockage of the urine. Over several months, the body’s immune system reabsorbs the dead tissue and replaces it with scar. This scar tissue slowly contracts resulting in shrinkage of the prostate. Over a six- month period, the prostate will shrink by 20-40%, resulting in improved and less frequent urination.
During the PAE procedure
General anesthesia is not used for the PAE procedure, so the patient will not be “put to sleep”. The patient will receive IV medications that take away pain and anxiety with the goal of making them comfortable for the entire procedure. The procedure itself is not painful. The most discomfort that patients report is from lying flat on their backs for the duration of the procedure.
The PAE procedure can be challenging because of the very small size of the prostatic arteries and the ‘twists-and-turns’ that need to be navigated with the catheter to get to them. However, the interventional radiologists at UNC have been using the same techniques in other parts of the body for many years, giving them the knowledge and skill to be able to perform PAE.
After the PAE procedure
Because the PAE procedure does not involve surgery or physical removal of part of the prostate, the patient will not see results immediately. The first changes are seen most commonly 1-2 months after the procedure with continued improvement until 5-6 months afterward.
According to the data on PAE that has already been published, PAE provides satisfactory improvement for 75-80% of men who undergo the procedure. The reason it does not work for some is either related to the inability to complete the embolization due to the size and location of the arteries or an inherent weakness in the bladder that does not resolve after the prostate shrinks.
Because this is a new procedure, there is no long-term data available yet. From the studies that have been done, the results of the PAE procedure last for at least 3-4 years. However, they could last much longer and further study is needed to determine this.
Possible Medical Risks
As with any medical procedure there are some risks involved, but with PAE, they are mild. The greatest risk comes from the accidental injection of particles into arteries not supplying the prostate, but the bladder or rectum instead. This could result in death of tissue within these organs.
At UNC, the physicians have a valuable technology called Cone Beam CT. This allows the physicians to obtain CT images on the procedure table that simulate the injection of the particles before the actual injection takes place. During this simulation, they can see if any of the particles will be going into the wrong arteries, allowing them to make any necessary adjustments before the actual embolization.
As there is no pathway from the prostate to the lungs or brain, it is impossible for the particles to cause blood clots in the lungs, leading to a possible stroke. The particles all become lodged in the prostate. The particles do not dissolve and are permanent. Interventional radiologists have been using the same particles for other procedures for many years and have not seen any problems arise from them.
Other small risks of the procedure include blood in the urine, semen, or stool; leakage of blood in the puncture site; bladder spasm; or infection of the puncture site or prostate. All of these potential complications will either resolve on their own or can be treated with a short course of medication.
The University of North Carolina is leading a study to evaluate the use of prostatic artery embolization (PAE) in patients with severe benign prostatic hyperplasia (BPH). In the study, physicians are evaluating the usefulness of PAE specifically for men with extremely large prostates, measured at greater than 80 grams or cm3 on ultrasound, CT or MRI. There are other conditions that could prevent someone from enrolling including kidney dysfunction, suspicion for prostate cancer or bladder stones.
If a patient is 65 years old or older and enrolled in Medicare, the costs of the PAE procedure and all of the other research-related tests will be covered by Medicare, once the patient is accepted into the study. If a patient does not have Medicare, health insurance companies are not covering the procedure in most cases. However, they may cover the costs of other tests associated with the research.
If a patient does not qualify for the PAE research study, there may be other opportunities to have the procedure performed at UNC. The UNC interventional radiologists encourage any patient or physician who wants more information on PAE to contact them to discuss the options that are available.