Interventional Radiology

Depending on the location of the stone and the size of the pet, there are multiple procedures that may be recommended for both dogs and cats.

Laser lithotripsy: With this procedure, a laser fiber is passed through a scope in the urethra and is used to break the stones into smaller pieces so they may be removed by a basket during the procedure or be passed during urination. The pet will typically go home the same day or the following day.

Percutaneous cystolithotomy (PCCL): This is a minimally invasive procedure where a small (approximately 0.5-1.5cm) incision is made and a scope is inserted into the abdomen and the bladder. Stones are flushed or removed with a basket. The pet will typically go home the same day or the following day.

Urinary stent or bypass device: If the stone is obstructing passage of urine and is more chronic in nature, we may recommend placement of a stent to bypass the obstruction. This may be done via the urethra, through the skin into the kidney or as an open surgical procedure.

Urinary incontinence is more frequently seen in dogs than cats. Urethral sphincter mechanism incontinence is seen most often in middle aged to older female dogs, but may affect any age and gender. The sphincter muscle that keeps the bladder closed loses strength, resulting in urine dribbling (mild to severe). If medical management fails, there are several alternate options:

Urethral bulking agent: With this procedure, a bulking agent is injected into the wall of the urethra. This is a minimally-invasive procedure that may need to be repeated periodically (up to once yearly, but may be less frequent).

Hydraulic occluder placement: A donut-shaped silicone tube is placed around the urethra – similar in appearance to a small blood pressure cuff, which is done through an incision into the abdomen. The tube may be later distended through a port under the skin, to manage incontinence.

Tumors of the bladder, prostate, and urethra most often cause problems by obstructing the passage of urine, leading to a urinary obstruction. There are several minimally invasive options for palliative management of urinary tumors.

Stents may be placed in the ureters, prostate, or urethra, bypassing or pushing the tumor out of the way to allow for more normal urine flow.

Laser therapy may be used to debulk tumors via a scope (similar to lithotripsy)

Small and toy breed dogs such as Yorkshire Terriers, Toy Poodles, Chihuahuas, Pugs, and others may have a deficiency of the cartilage of the trachea, resulting in weakening of the trachea over time. This may cause chronic dry cough, a “goose honk” cough, difficulty breathing, and occasionally collapse.

For dogs that are severely affected or have failed traditional medical management, a tracheal stent may be placed. In this procedure, the trachea is pushed outward to a more normal shape by the stent which is permanently within the trachea.

Dogs and cats may develop a stricture or narrowing of the nasopharynx (the area above the soft palate at the back of the nose). In dogs, this is most often secondary to gastro-esophageal reflux (which sometimes occurs as a separate disease process or associated with anesthesia). In cats, this is most often associated with chronic upper respiratory disease (rhinitis). In both dogs and cats, signs may include noisy breathing, exaggerated swallowing, difficulty swallowing, nasal discharge, and open mouth breathing.

For both dogs and cats, nasopharyngeal ballooning, where a stiff balloon is inflated within the stenosis, breaking down the scar tissue, may be done. In certain cases, placement of a stent may be more appropriate. Both procedures are done via the mouth and nasal cavity.

This is a congenital disease where an anomalous vessel carries blood directly from the vessels of the gastrointestinal tract to the general circulation, bypassing the liver. This form of PSS is seen more commonly in large breed dogs and rarely cats. Pets may have poor growth rates, remain underweight, have vomiting and diarrhea, and show neurologic signs such as dullness, circling, excessive salivation, and occasionally seizures.

Coil embolization: Via a vessel in the neck or leg, a stent is placed within the vena cava where the anomalous shunt vessel is entering. Thrombogenic coils are deployed on the shunt side of the stent, which eventually increases the pressure for blood trying to enter the anomalous vessel. Because blood goes down the path of least resistance, as the shunt vessel closes, blood will be re-routed to the normal circulation via the liver.

Certain types of liver tumors may be very large at the time of diagnosis and may not be amenable to surgical removal, which is typically the treatment of choice.

Chemoembolization: With this procedure, the arteries supplying the tumor are located by entering through the arteries in the leg or neck. Once the tumor blood supply is isolated, it is treated with chemotherapy mixed with an embolizing agent that decreases blood flow. It may be more effective to decrease tumor growth than intravenous chemotherapy.

Dogs and cats rarely develop esophageal cancer; colonic cancer causing obstruction is slightly more common. Strictures, or narrowing, of both esophagus and the colon are also possible. Partial or complete obstructions of the esophagus may cause regurgitation and difficulty swallowing. Partial or complete obstructions of the colon may cause difficulty defecating, constipation, and ribbon-like stool.

Depending on the disease process, either balloon dilation of the stricture or placement of a stent, which pushes abnormal tumor tissue out of the way, may be performed. These procedures are done via the mouth or rectum.