Juan Montoya: Hello, I’m Dr. Juan Montoya. I’m a urologist and the President of the Urology Center of Colorado. In this video, I will demonstrate the application technique for SpaceOAR® Hydrogel. SpaceOAR® Hydrogel is a temporary spacer that separates the prostate from the rectum. With this separation, the volume of normal tissue exposed to the radiation is greatly reduced. This may dramatically lower the complications related to radiotherapy. Both the fiducial markers and the SpaceOAR® Hydrogel are placed through a transperineal approach under local anesthesia. This procedure is well tolerated by patients, easily performed in the office setting and generally takes a short period of time.
On the day of the procedure, each patient is instructed to eat a light breakfast and will receive a fleets enema two hours prior to the procedure. The patient will pre-medicate with 5-10 milligrams of Valium® as well as 5/325 milligram Percocet® one hour before the procedure. Patients are accompanied by a responsible adult or will have transportation arranged. At our center, we also prescribe a prophylactic antibiotic of Levofloxacin 500 milligrams orally one hour before the procedure.
The patient is brought into the treatment room and placed in the dorsal lithotomy position with stirrups. The buttocks is positioned at the end of the table. This provides maximum access to the perirectal space for visualizing the needle approach to reach the mid gland of the prostate. I find that conversing with the patient during the procedure allows them to relax and improves their experience.
The patient’s scrotum is held away from the perineum with a medium-size ioban. Lidocaine and prilocaine cream is applied to the perineum 5 to 10 minutes prior to aseptic preparation using chlorhexidine.
A sterile field is used to prepare the lidocaine for the local anesthetic and to assemble the space for Hydrogels syringes. For the local anesthetic, we use 20 milliliters of 2% lidocaine buffered with 8.4% sodium bicarbonate at a 10 to 1 ratio. In addition, we have a syringe with sterile saline for the hydrodissection, three fiducial markers and the SpaceOAR® Hydrogel kit.
The transrectal ultrasound probe is covered by a condom and inserted into the patient’s rectum. After donning sterile gloves, I administer the local anesthetic. Using a 25 gauge needle, I create a skin wheel with local anesthetic at the insertion site that is approximately one to two centimeters above the probe. Using the same needle, I inject two to three CCs into the deeper subcutaneous tissue. I then switch the spinal needle and under ultrasound guidance, anesthetize the anticipated needle track for the fiducials and spacer. Again, with ultrasound, I advance the needle to the prostatic apex on the right and inject approximately two to three CCs of local.
I will withdraw the needle halfway to the skin and redirect it to the patient’s left prostatic apex where another two to three CCs is infiltrated. These apical injections will abut the prostate capsule. This procedure allows adequate anesthesia for both the fiducial markers and the Hydrogel injection. In total, I generally use between 12 to 15 CCs of anesthetic.
Next, I will prepare the SpaceOAR® device which will allow time for the lidocaine to take full effect. I will then place the fiducials followed by the SpaceOAR® Hydrogel. Using sterile technique, remove the end cap from the diluent syringe with a blue label and attach that syringe to the powder vial. Without depressing the plunger, push the syringe into the vial cap until it is fully depressed, piercing the vial seal. The red line will disappear below the rim. Now inject the syringe contents into the vial. Shake the vial syringe assembly until the powder is completely dissolved and set it aside to help dissipate bubbles. Remove the accelerator syringe cap, expel liquid as needed so the five milliliters remains in the syringe. Then pull back once you see [inaudible 00:04:40].
With the syringe held upright and holding the syringe barrel, attach to the accelerator syringe to the Y-connector. Use caution not to depress the syringe plunger to avoid fluids entering the Y-connector. You can see that the powder vial precursor that has been resting is now clear and most of the bubbles have dissipated. Invert the precursor syringe assembly and withdraw five milliliters into the syringe. Avoid drawing bubbles. Unscrew the syringe from the powder vile than pull back one milliliter of air. Holding the syringe upright, attach the precursor syringe to the Y-connector. Attache syringe holder to the two syringe barrels. Carefully attach the plunger cap to the plungers of both syringes while firmly holding the plungers to avoid dispensing solution into the Y-connector.
Now that the patient is sufficiently numbed, I will place the fiducial markers. The fiducial markers are placed via a transperineal approach. At our institution, we place three markers with the goal to triangulate the markers within the prostate. One fiducial is placed at the lateral base, one at the apex of the gland, with a third marker mid gland on the contralateral side.
The next step is to perform hydrodissection to ensure that the space between the prostate and the anterior rectal wall opens. Now I will attach the 18 gauge needle that is provided in the device tray to the saline syringe and prime the needle to make sure there is no air left in the needle itself. Under sagittal ultrasound guidance and with the transrectal probe caudally placed to view needle advancement, the hydrodissection needle, bevel down, is advanced through the midline, about one and a half centimeters anterior to the probe and at a 10 to 15 degree downward angle. The needle tip is positioned and then is advanced along the Denonvilliers’ fascia and anterior rectal wall interface until it is within the mid gland, fat plane. Switching to the axial view, the needle tip is located and confirmed to be in the prostate mid gland. Very slight needle tip movement confirms that the needle tip is correctly positioned in the fat plain and that the tip moves independently of the anterior rectal wall or Denonvilliers’ fascia. A slight one milliliter saline puff with symmetric saline distribution further confirms proper needle tip positioning.
Once the initial puff confirms an appropriate location, further hydrodissection in the sagittal plane is performed to open the space and ensure adequate coverage from base to apex. In the event that the initial puff reveals improper positioning, the needle can be readjusted and a one CC puff can be repeated. With the needle tip again at mid gland, an axial view confirms midline needle positioning and bilateral hydrodissection. I typically use 5 to 10 CCs of saline. Aspirate to ensure that the needle is not intravascular. Now I will detach the saline syringe, keeping my hand still so I do not move the hydrodissection needle.
Before attaching the SpaceOAR® syringe, advanced the plunger to expel air only up to the top of the syringe. Do not allow the fluids to enter the Y-connector as this could clog the device. Being careful to maintain the needle position. Attach the SpaceOAR® system assembly to the 18 gauge needle. Recheck the axial view to confirm the needle position. Under ultrasound guidance in the sagittal view, use a smooth and continuous injection technique to dispense the SpaceOAR® Hydrogel into the space between the prostatic fascia and the rectum. The entire contents should be injected over approximately 10 seconds without stopping. Then withdraw the needle syringe assembly and discard the SpaceOAR® system device. I will then view the image in the sagittal view to make sure the gel dispersed from apex to base, and in axial view to determine if the gel provided good separation. An MRI scan confirms that the gel had very good disbursement from apex to base