Evaluation of Biomaterials for Bladder Augmentation using Cystometric Analyses in Various Rodent Models

The aim of this procedure is to evaluate the use of biomaterials for bladder augmentation by acquiring functional data by cytometry. This is accomplished by first aner mosin, the scaffold to a defect created in the bladder. The second step of the procedure is tunneling the cystostomy tube to the abdomen.

The third step is placing the cystostomy tube into the augmented bladder and securing it on the dorsum of the animal. The final step is performing cytometry to evaluate the augmented bladder from a functional standpoint. Ultimately, results can show changes in bladder capacity and compliance, voiding pressures, nutrition cycle times, and post void residual volumes through conscious cytometry.

The implications of this technique extend toward therapy of congenital and acquired anomalies of the bladder or urethra that lead to impaired bladder capacity, compliance, and overall function. Because novel biomaterials used for bladder augmentation need to be evaluated functionally. After preparing an animal for abdominal surgery, use a scalpel to make a lower midline incision through the skin.

Using toothed forceps, elevate the rectus muscle and dissect free the posterior surface of the muscle with fine mets and balm scissors size the remainder of the muscle in the midline for the entire length that the skin incision deliver the bladder through the incisional wound place. Once day, suture through the posterior wall of the bladder and then through the anterior wall of the bladder place. Additional sutures laterally on the bladder do not tie these sutures.

When the sutures are held tort, the bladder will have a square configuration measuring approximately one centimeter square in size, the bladder longitudinally through the anterior bladder wall, just inferior to the dome of the bladder along the midline. Be careful not to have too much tension on these sutures as they can easily be pulled through the bladder tissue For this step, loop magnification is preferred for anastomosis of the scaffold. Using fine scissors, trim the silk scaffold to the approximate area of the bladder defect.

Start at one corner of the scaffold and suture it to the bladder in a continuous running fashion. To create a watertight seal all the way around the defect, It is very important for the surgeon to perform a tension-free watertight anastomosis of the scaffold to the bladder. This will ensure the containment of all urine inside the bladder as any intraperitoneal leak will likely result in animal mortality.

As a test, use a 30 gauge hypodermic needle to load the bladder with water. If a leak is found, close it with an additional interrupted suture. Then reduce the reconstructed bladder back into the abdomen prior to closure of the abdominal wall.

Inject the rectus muscle and subcutaneous tissue with bupivacaine for local anesthesia and close the incision. Next, use a continuous running suture to re approximate the rectus muscle and close the skin with a continuous running suture. After cleaning and drying the incision, transfer the animal to a warm, clean cage for awakening from the anesthesia.

Before beginning, create an anchor at the end of a 10 centimeter PE 50 tube so it does not slip out of the bladder. Do this by flaring the end of the tubing by gently exposing it to a flame. Second, verify that the tube has not been occluded.

Inject the non flared end with saline and make certain it flows. After preparing an animal for surgery, before exposing the bladder, make a one centimeter incision on the dorsum between the scapula. Using the metson balm scissors, develop a plane between the skin and the underlying muscle.

Then place the tips of the scissors in the plane and spread them to create a subcutaneous tunnel to the ventral abdomen. Next, flip the animal over. Expose and return the bladder to the abdomen.

Returning to the dorsal incision, place a small clamp into the subcutaneous tunnel. Use your fingers to protect the intraabdominal contents, and then use the tips of the clamp to pierce through the abdominal wall. Now, grasp the smooth end of the flared tube with the clamp and pull it back through the dorsal incision.

Do not pull the flared anchor end past the abdominal wall with the tube through the incision. Place a purse string stitch at the dome of the bladder. Leave a small clamp on the loose end of the suture so that it is not inadvertently pulled through the stitch.

Also, do not pull the suture taut. Now EU 18 gauge needle to pierce the bladder wall at the center of the purse string suture just enough to be intraluminal. Then place the fine forceps in the opening and gently spread them to widen the hole.

Insert the flared end of the catheter into the defect in the bladder until it is intraluminal. Pull the purse string suture tighter around the catheter and tie it down. Then wrap the free suture around the catheter once and tie it down.

Now, test the bladder by slowly injecting saline into it via the tube. If there is flow from the urethra, aspirate the saline to decompress the bladder.Again. If a leak is found, this should be repaired with suture, a urine leak can result in mortality.

Close the abdominal incision as previously demonstrated. Then proceed with closing the dorsal incision. The procedure for closing the dorsal incision is different for rats and mice.

For rats, use scissors to cut the catheter tubing at the level of the skin. Then insert a 22 gauge blunt tip needle into the tubing. Use running sutures to close the skin over the tubing, leaving the needle hub extruded.

Now place an intravenous line cap on the blunt needle and secure the catheter tip to the skin. Afterwards, clean the incision and allow the animal to recover in a warm environment. In mice, the catheter should be secured as follows, leave the catheter long and occlude the end of the catheter by melting it with a flame.

Coil the end of the tubing and leave it in the subcutaneous pouch on the dorsum of the animal. Close the skin over the tubing in a continuous running fashion. Prior to cytric analysis, allow at least five to seven days of postoperative recovery for either rats or mice.

After recovery on the day of cytometry. For mice, it is necessary to first open the dorsal incision under anesthesia and remove the coiled tubing from the subcutaneous pouch. After removing the tubing, close this incision and wait for the mouse to fully awaken from anesthesia before performing the cytometry begin by placing the animals in metabolic cages suspended over scales.

Now access the supra pubic catheters with a 27 gauge needle connected via a ttu to the pressure transducer and the infusion pump. Begin the infusion of physiologic saline. Allow the voiding pattern tracing to stabilize.

Over the next 10 to 20 minutes, the bladder pressure first rises, and this is followed by a void. Then record the tion cycles for 15 to 120 minutes, or at least three or four voiding cycles during the procedure. Watch for catheter kinking and other complications.

Urodynamic tracings can then be analyzed to derive parameters such as voided volumes, compliance, peak voiding pressures into contraction, interval, micturition cycle time, and post void residual volumes. After watching this video, you should have a good understanding of how to augment the bladder using any biomaterial. You will also know how to evaluate function of any rodent bladder using conscious unrestrained cytometry.