CHICAGO (CBS) -- As any animal owner will tell you, pets are precious members of the family.
So, when one suburban family discovered a life-threatening condition with their beloved dog, they allowed her to become the second-smallest dog to undergo a unique procedure.
Five months ago, the Cassidy family dog, Tiffany, left a routine checkup and something, clearly, was wrong.
"When we walked out, she went on all fours down on the ground," said Pam Cassidy. "She couldn't hold her weight up."
The vet first thought Tiffany was having a bad reaction to her vaccinations, but it was actually a problem with her liver.
"It's a vessel that's bypassing the liver and taking all the toxins throughout the body," said vet Cris Otoni. "When those toxins run through the brain, that's when they are having the symptoms"
"Basically she was acting like she was drunk all the time," said Brett Cassidy.
Vets put Tiffany on medication, but she needed more.
Surgery on the liver to treat this condition is risky. Now vets prefer minimally invasive treatment, entering through the jugular vein. However, the procedure is difficult for a dog of Tiffany's size.
That's when vets from the VCA in Downers Grove stepped up to the plate.
"There's a worry that her jugular vein was going to be too small to pass all the guide wires that were needed," said VCA's Felipe Galvao. "There was a worry we weren't going to be able to find the vessel."
In spite of any concerns, there wasn't much of a choice. "I don't think she had very long to live," Galvo said.
The team performed the two-hour surgery, coiling off the bad vessel and putting a stent in the good vessel to guide the blood in the right direction. The procedure cost $20,000, but the Cassidy family said the price was worth it.
"It was really a miracle how quickly she changed," said Brett Cassidy.
Tiffany had been diagnosed with an intrahepatic portosystemic shunt (IHPSS). Normally, all of the blood that come from the intestines flows directly to the liver so the liver is able to process toxins coming from the intestinal tract. Shunts occur when there is a direct communication between the blood coming from the intestines (portal circulation) and the systemic circulation (caudal vena cava). This is a congenital abnormality. Shunts can be classified as extrahepatic (where the communication occurs outside of the liver) or intrahepatic (communication occurs within the liver). The treatment that provides the best outcome is to correct the shunting vessel. Unfortunately, this is challenging to do in intrahepatic shunts since the surgeon would have to dissect the liver, which has been associated with many complications. Surgical approaches for IHPSSs have been associated with complication rates as high as 77%, perioperative mortality rates as high as 64%. This prompted the need of developing alternative treatment options for these patients.
Endovascular techniques were developed to close the shunting vessel (i.e. decrease blood flow through the shunting vessel). This technique involves passing guidewires and catheters through the jugular vein (typically) and accessing the shunting vessel. Thrombogenic coils are placed within the shunting vessel to decrease flow. A stent in the caudal vena cava is placed in order to prevent the coils from migrating into the systemic circulation. Portal pressures are measured during the procedure to make sure that the coils are not significantly increasing portal pressures, which could be associated with gastrointestinal side-effects. Patients normally remain in the hospital for 1-2 days after the procedure. Possible intra-op complications are low, but can be due to portal hypertension, coil displacement, arrhythmias (if caval stent is placed within the right atrium - more of common with left divisional portosystemic shunts). Possible post-operative complications include seizures, hemorrhage from the jugular access site, and portal hypertension. Fortunately, these are not common complications.
Overall, endovascular procedures have lower morbidity and mortality when compared to conventional surgical procedures. Outcome of endovascular procedures is considered excellent or fair in approximately 80% of patients. The median survival post-procedure is approximately 6 years. Most of the treated patients do well with one procedure (~85%). However, approximately15% may benefit from additional coils. There are 5% of dogs that have a high pressure gradient that do not require treatment. When evaluating outcome according to shunt location, excellent outcome was achieved in 80% of central divisional, 67% of right divisional, and 48% of left divisional intrahepatic shunts. Left divisional intrahepatic shunts are most cranially and most likely to develop collaterals.
Gastrointestinal bleeding was initially noted in approximately 13% of dogs prior to endovascular treatment. The risk of gastrointestinal bleeding has decreased significantly after life-long omeprazole treatment has been recommended.
A CT scan is necessary prior to the endovascular procedure in order to map the shunting vessel. Then, a separate procedure will be scheduled for the endovascular procedure. This helps to minimize anesthesia time as well as intravenous contrast load. We recommend performing these procedures when patients are somewhere between 4-6 months of age. The risk in doing them when they are very young is that we don't want them to over their caval stent since vessel size may increase in diameter as they grow.
Tiffany has continued to do well!